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Silva Fennica 1926-1997
1990-1997
1980-1989
1970-1979
1960-1969
Acta Forestalia Fennica
1953-1968
1933-1952
1913-1932

Articles containing the keyword 'pulp'

Category : Article

article id 5614, category Article
Mika Jääskelä, Kari Heliövaara, Mikko Peltonen, Hannu Saarenmaa. (1997). Comparison of protection methods of pine stacks against Tomicus piniperda. Silva Fennica vol. 31 no. 2 article id 5614. https://doi.org/10.14214/sf.a8515
Keywords: forest protection; GIS; Tomicus piniperda; timber storage; insect pests; road side landings of timber; pulpwood stacks; protection of timber
Abstract | View details | Full text in PDF | Author Info

Three most promising protection methods of pine pulp wood stacks against the attacks of Tomicus piniperda L. were compared. The methods were the covering of stacks by fibreglass-strengthened paper or twofold achrylene netting, removing the upper parts of stacks, and enhanced planning of the placement of the timber store using ARC/INFO GIS-software. T. piniperda was observed to strongly prefer the upper parts of the stacks: 90 % of the beetles occurred within 0.5 meters of the top of the stacks. Covering of the stacks decreased the attack density of T. piniperda, and the protection effect of covering was 80 %. Due to long transport distances and fragmentation of forest landscape the relocation of timber store was found to be an unsuitable method in the practical level. Also, taking into account the costs of the method, removing of the upper parts of stacks was considered to be the optimal solution.

  • Jääskelä, E-mail: mj@mm.unknown (email)
  • Heliövaara, E-mail: kh@mm.unknown
  • Peltonen, E-mail: mp@mm.unknown
  • Saarenmaa, E-mail: hs@mm.unknown
article id 5570, category Article
Anne Toppinen, Riitta Hänninen, Susanna Laaksonen. (1996). A dynamic forecasting model for the Finnish pulp export price. Silva Fennica vol. 30 no. 4 article id 5570. https://doi.org/10.14214/sf.a8505
Keywords: inventory; Finland; cointegration; business cycles; pulp; price; sulphate pulp; export prices
Abstract | View details | Full text in PDF | Author Info

This study investigates the relationship between Finnish sulphate pulp export prices and international pulp inventories using the Johansen cointegration method. Long-run equilibrium is found to exist between pulp price and NORSCAN inventory for the study period, 1980-94. Granger causality is found to exist from inventory to price but not vice versa. A simple short-run forecasting model for the Finnish pulp export price is formed. In preliminary analysis, the explanatory power of model is found to be acceptable but only under stable market conditions.

  • Toppinen, E-mail: at@mm.unknown (email)
  • Hänninen, E-mail: rh@mm.unknown
  • Laaksonen, E-mail: sl@mm.unknown
article id 5522, category Article
Jari Kokkola. (1993). Drying of pulpwood in northern Finland. Silva Fennica vol. 27 no. 4 article id 5522. https://doi.org/10.14214/sf.a15683
Keywords: pulpwood; storage; moisture; green weight; storage weight loss
Abstract | View details | Full text in PDF | Author Info

Drying of pulpwood bolts of Scots pine (Pinus sylvestris L.), birch (Betula spp.) and Norway spruce (Picea abies (L.) H. Karst.) was studied by measuring the drying of sample bolts placed in experimental piles. The results revealed that the main factors affecting timber drying are debarked surface area, moisture content at the time of felling and the size of the bolt. Furthermore, pine and spruce bolts located in the upper part of the pile dry better than bolts near the ground.

The investigation of green weight changes of whole piles of pine and birch was based on data collected in 1987–91. The green weight of piles was dependent mainly on storage time and on region; effect of weather variables could not be distinguished. Specific calibrating coefficients for motor-manual and mechanical cutting were included in the green weight equations.

Comparison between green weight equations and detected weight losses of sample piles indicates that fitted models seem to produce at least approximate results for the green weights, the said results thus lending themselves to be utilized as part of a transportation cost model.

The PDF includes an abstract in Finnish.

  • Kokkola, E-mail: jk@mm.unknown (email)
article id 5371, category Article
Riitta Laurila. (1989). Pieniläpimittaisen männyn kuituominaisuudet. Silva Fennica vol. 23 no. 1 article id 5371. https://doi.org/10.14214/sf.a15530
English title: Fibre properties in Pinus sylvestris pulpwood.
Original keywords: kuitupuu; pienpuu; mänty; trakeidit; puuaineen ominaisuudet; kuitujen pituus; soluseinän paksuus
English keywords: Pinus sylvestris; cell wall thickness; wood properties; pulpwood; small-sized stems; tracheid length; smallwood
Abstract | View details | Full text in PDF | Author Info

Properties of fibres in pulpwood, especially length, width and the thickness of walls in tracheids, are essential for strength properties of pulp and paper. Length and width of tracheids increase from pith to surface in radial direction. Young and small-sized stems have also smaller fibres. Small-sized Pinus sylvestris L. test trees had tracheids that were shorter both in stems and knot wood than those in normal sized trees. However, cell walls in test trees were as thick as in normal sized trees. It seems that especially the L/T -ratio (length/thickness) in small stems is worse than in normal sized pulp wood.

The PDF includes an abstract in English.

  • Laurila, E-mail: rl@mm.unknown (email)
article id 5267, category Article
Matti Kärkkäinen. (1986). Mänty- ja kuusirunkojen arvosuhteet. Silva Fennica vol. 20 no. 2 article id 5267. https://doi.org/10.14214/sf.a15446
English title: Value relations of Scots pine and Norway spruce stems.
Original keywords: kuusi; paperiteollisuus; mänty; sahatavara; sahateollisuus; raaka-aine; rungon koko
English keywords: Pinus sylvestris; Norway spruce; Picea abies; Scots pine; simulation; pulping; sawn goods; sawmill industry; pulp industry; raw material; stem size
Abstract | View details | Full text in PDF | Author Info

A mathematical model was developed for determining the value of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.) stems on the basis of sawing and pulping. The model was based on selling prices of sawn goods, pulp and other products as well as processing costs. Sawing was applied to large-dimension parts of stems and pulping to other parts and small stems. Bark and other residues were burned. The quality of pine stems was described by the distance of the lowest dead branch. In spruce only stem size affected the quality-

According to the results, the size of stem affects considerably the value of pine stems and clearly that of spruce stems. The main reason is an increase in the productivity of frame sawing as the stem size increases. In pine another factor is the higher price of sawn goods. The effect of pulp price increases as the stem size decreases. Even in large sized stems the effect of pulp was notable as the value of chips and saw dust was determined on the basis of product values in export. The competition ability of mechanical pulp was greatly affected by the price of electricity.

The PDF includes an abstract in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 5187, category Article
Fuhe Luo. (1983). Determination of stem value. Silva Fennica vol. 17 no. 3 article id 5187. https://doi.org/10.14214/sf.a15170
Keywords: Pinus sylvestris; Scots pine; modelling; pulpwood; saw log; stem value; taper curve model; bark model; cubic spline interpolation
Abstract | View details | Full text in PDF | Author Info

A dynamic programming approach toward stem value estimation for standing Scots pine (Pinus sylvestris L.) trees was developed. The determination of the saw log value was based on the sawing pattern and on the final products composition. The combination of taper curve models and bark models providing taper curves both over bark and under bark, which constituted the basis of the optimum stem scaling. A computer program was developed to determine the optimum log sequence of the stem aiming at maximizing the value of the final products. To examine the reliability of the computation system, 445 Scots pine sample trees from 29 stands were used as a test material. The stem values of sample trees were calculated in two ways: 1) with 12 measured diameters, and 2) with 12 estimated diameters derived from measured tree characteristics. In both cases the values of the intermediate diameters were calculated via cubic spline interpolation.

The PDF includes a summary in Finnish.

  • Luo, E-mail: fl@mm.unknown (email)
article id 5166, category Article
Rihko Haarlaa, Matti Kärkkäinen. (1982). Tervalepän kuitujen pituus. Silva Fennica vol. 16 no. 4 article id 5166. https://doi.org/10.14214/sf.a15081
English title: Fibre length in common alder.
Original keywords: kuitupuu; tervaleppä; puun anatomia; kuidut
English keywords: fibre length; Alnus glutinosa; pulpwood; fibres
Abstract | View details | Full text in PDF | Author Info

A material consisting of 21 common alder (Alnus glutinosa (L.) Gaertn.) trees from 11 stands was collected. From each stem discs were sawn by 2 m interval. Samples were taken of the discs from various distances from pith. They were macerated and the average fibre length was based on 50 observations.

The fibre length increased significantly from the pith to the disc surface. The increase was approximately similar at various heights of the tree. The tree characteristics had only minor effect. However, near the pith the increase in fibre length was higher in trees with wide growth rings than in other trees. Near the disc surface the growth rate had no effect. In typical pulpwood bolts the average length was 800–950 μm which corresponds well to the data given in the literature.

The PDF includes a summary in English.

  • Haarlaa, E-mail: rh@mm.unknown (email)
  • Kärkkäinen, E-mail: mk@mm.unknown
article id 5162, category Article
Jarmo Eronen. (1982). Soviet pulp and paper industry: Factors affecting its areal expansion. Silva Fennica vol. 16 no. 3 article id 5162. https://doi.org/10.14214/sf.a15077
Keywords: paper industry; pulp industry; Soviet Union; USSR; investment strategy; wood raw material; timber reserves; relative costs
Abstract | View details | Full text in PDF | Author Info

Planners of the Soviet pulp and paper industry are constantly faced with the problem: which investment policy guarantees the best location structure? Should one invest in existing localities or expand to new areas, especially in heavily forested parts of Siberia? A location theory for the pulp and paper industry, based on three factors (markets, wood raw materials, relative costs) has been suggested by the Soviet authors Antonov and Trusova. In the present study the theory is – for the first time – given empirical contents and the feasible areas for future growth of the industry are tentatively determined. One of the main findings of the study is the detecting of considerable unutilized wood reserves in the European USSR. This supports those Soviet views advocating a European-oriented location in investment strategy for the industry, as market and cost factors are unfavourable to Siberian location.

The PDF includes a summary in Finnish.

  • Eronen, E-mail: je@mm.unknown (email)
article id 5149, category Article
Toini Holopainen. (1981). Alterations in the ultrastructure of epiphytic lichens Hypogymnia physodes and Alectoria capillaris caused by air pollution. Silva Fennica vol. 15 no. 4 article id 5149. https://doi.org/10.14214/sf.a15376
Keywords: lichens; air pollution; bioindicators; indicator plants; Hypogymnia physodes; fertilization plant; pulpmill; Bryoria capillaris; ultrastructure
Abstract | View details | Full text in PDF | Author Info

The ultrastructure of Hypogymnia physodes (L.) Nyl. and Alectoria capillaris (Bryoria capillaris (Ach.) Brodo & D. Hawksw.) grown or transplanted near a fertilizer plant and a pulp mill was compared to normal ultrastructure of these lichen species. The ultrastructural changes observed were highly similar in the symbionts of both species and near both the factories although the emissions are different. In the lichens grown near the factories the number of algae had clearly increased. The appearance of the chloroplasts was roundish compared to controls. The pyrenoglobuli and cytoplasmic storage bodies were smaller than normally and the number of polyphosphate bodies had increased. Also, in mycobionts storage droplets were very small or absent and many vacuoles and dark inclusions appeared to hyphae in contrast to controls. In transplanted lichen there existed mainly the same ultrastructural changes as in the lichen grown near factories. Near the fertilizer plant the damage was, however, more severe because all the lichens died during 6–7 months after transplantation. Near the pulp mill part of the lichens survived and seemed to adapt to air pollution.

  • Holopainen, E-mail: th@mm.unknown (email)
article id 5051, category Article
Aili Tuimala. (1979). Kuusen lahon aiheuttamista puutavaralajisiirtymistä ja kantohintamenetyksistä. Silva Fennica vol. 13 no. 4 article id 5051. https://doi.org/10.14214/sf.a14908
English title: Changes in timber assortments and loss in stumpage prices caused by decay in growing Norway spruce timber.
Original keywords: kuusi; kuitupuu; puukauppa; tukkipuu; laho; puutavaralaji; tulonmenetys; puutavaralajisiirtymä
English keywords: Norway spruce; Picea abies; pulpwood; decay; timber; timber assortments; loss of income
Abstract | View details | Full text in PDF | Author Info

Material for this study was collected from 26 stands marked for clear cutting in Southern Finland. The volume of decayed Norway spruce (Picea abies (L.) H. Karst.) timber and pulpwood was determined by deducting the volumes of these assortments (as recorded on the measurement certificate) from the volume of the standing trees. To obtain the economic loss, the volume of decayed wood was multiplied by the difference in stumpage prices between spruce timber of pulpwood and pine pulpwood. In the 17 stands of Buyer A the loss in timber volume caused by decay was 5.84% and the loss in stumpage price 2.84 Fmk/m3 (means weighted by volume). The corresponding figures in the 9 stands of Buyer B were 10.87% and 5.50 Fmk/m3, respectively.

At the mean stumpage price level for the felling season 1977-78 the losses in the stands m.f.c. mentioned above were 2.87% per unit price in the stands of Buyer A and 5.75% in the stands of Buyer B.

The PDF includes a summary in English.

  • Tuimala, E-mail: at@mm.unknown (email)
article id 5034, category Article
Matti Kärkkäinen. (1979). Pinotilavuusmääräinen kuorintahäviö koneellisesti ladotuissa pinoissa. Silva Fennica vol. 13 no. 2 article id 5034. https://doi.org/10.14214/sf.a14891
English title: Barking loss of mechanically loaded piles.
Original keywords: kuitupuu; mänty; puutavaranmittaus; koivu; kuorinta; pinotilavuus
English keywords: birch; Scots pine; pulpwood; debarking; piled volume; stacked volume; barking loss
Abstract | View details | Full text in PDF | Author Info

In this study the loose volume of 58 piles of pulpwood were measured before and after barking by rotary ring barker. The volume was 2,121 m3. A recommendation is made, based on the results of the study, concerning the barking loss from piled wood: for green Scots pine (Pinus sylvestris L.) pulpwood, 8.8% of the stacked volume; for seasoned pine pulpwood, 6.1% of the stacked volume; and 8.0% for birch (Betula sp.) pulpwood, green and seasoned. The amount of bark left on bolts was small for pine bolts, namely 0.33%, but quite large for birch bolts, 2.84% of the green weight.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 5005, category Article
Matti Kärkkäinen. (1978). Kuorinnan vaikutus pinon tiiviyteen. Silva Fennica vol. 12 no. 3 article id 5005. https://doi.org/10.14214/sf.a14859
English title: The effect of barking on the pile density.
Original keywords: koneellistuminen; karsinta; kiintotilavuus; kuitupuun mittaus; pinomittaus; kuorinta; moottorisahakarsinta
English keywords: mechanization; pulpwood; limbing; pile density; measuring of piled wood; solid volume; debarking
Abstract | View details | Full text in PDF | Author Info

According to the available literature, the times when pulpwood limbing was made by axe and barking by hand tools, barking either had no effect on the pile density (if limbing quality was good) or increased pile density (if limbing was bad). When rotary barking machines are used, the branch stumps remain intact during barking. Therefore, if there are branch stumps in the pulpwood, barking decreases the pile density. Nowadays, when power saw limbing is a common practice in Finland, barking presumably greatly decreases the pile density, due to the fact that in power saw limbing branch stumps are numerous and high. Therefore, the method to estimate the solid volume of a pile of unbarked pulpwood are not applicable to barked pulpwood without modification.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4927, category Article
Matti Kärkkäinen. (1975). Kantojen käytön kehittyminen Suomessa. Silva Fennica vol. 9 no. 4 article id 4927. https://doi.org/10.14214/sf.a14769
English title: Development of stump utilization in Finland.
Original keywords: metsätalous; historia; polttopuu; tervanpoltto; polttoaineet; selluteollisuus; kannot; hyötykäyttö
English keywords: stumps; forestry; fuelwood; history; pulp industry; tar; utilization
Abstract | View details | Full text in PDF | Author Info

The utilization of stump and root wood is analysed in this paper on the basis of literature from middle of 19th century to the present date. According to the information available, the utilization of pine stumps in tar production was small compared to that of peeled Scots pine stemwood in the 19th century. During the 1st and 2nd World War the utilization of stumps for tar production reached its highest levels. Other industrial utilization of stumps has been small up to the present time but now stumps are beginning to be used in the pulp industry.

The greatest amounts of stumps have been utilized by the rural population. Stumps were used as fuel. In the thirties, the yearly amount used was over 200,000 m3 (solid measure), and even in the sixties over 100,00 m3. No industrial utilization method has yet reached these levels.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4899, category Article
Matti Kärkkäinen. (1974). Näkökohta tyvi- ja latvaläpimitan keskiarvoon perustuvasta mäntypölkkyjen kuutioinnista. Silva Fennica vol. 8 no. 2 article id 4899. https://doi.org/10.14214/sf.a14743
English title: Note on the volume based on the mean of butt and top diameters of Scots pine bolts.
Original keywords: kuitupuu; mänty; puutavaranmittaus; kapeneminen; tyviläpimitta; latvaläpimitta; kiintotilavuus
English keywords: Pinus sylvestris; Scots pine; pulpwood; timber scaling; tapering; butt diameter; top diameter; volume determination
Abstract | View details | Full text in PDF | Author Info

In this paper the use of butt and top diameters of pulpwood bolts for volume determination is analysed. The study is based on the taper data of Scots pine (Pinus sylvestris L.) stems. According to the results, the use of the mean of butt and top diameters in the volume determination under Finnish condition causes a positive error in small stems. If the stems are so big that the butt portions of the stems can be used as saw logs, the remaining top bolts, used as pulpwood, are estimated to be smaller than they are in reality. Accordingly, there is a negative error.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4896, category Article
Matti Kärkkäinen. (1974). Keskusmuotoluvun perusteita tukkien ja kuitupuun mittauksessa. Silva Fennica vol. 8 no. 1 article id 4896. https://doi.org/10.14214/sf.a14740
English title: Foundations of middle form factor in the measurement of logs and pulpwood.
Original keywords: kuitupuu; tukkipuu; puutavaranmittaus; menetelmät; muotoluku; kiintomitta
English keywords: logs; form factor; pulpwood; methods; timber scaling; determination of volume
Abstract | View details | Full text in PDF | Author Info

In this literature review some error possibilities in the measurement of solid volume of logs and pulpwood are discussed. Although both underestimation and overestimation can occur for various reasons it seems likely that in the stereometric measurement method the real volume is underestimated, at least when Huber’s formula is applied, and the respective middle form factors are too low. Numerous results of empirical investigations are presented in the paper, too.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4883, category Article
Matti Kärkkäinen. (1973). Näkökohta kuitupuupölkkyjen siirtelymatkasta. Silva Fennica vol. 7 no. 3 article id 4883. https://doi.org/10.14214/sf.a14720
English title: A note on the moving distance of pulpwood bolts.
Original keywords: hakkuut; kuitupuu; metsätyö; puunkorjuu; metsäkuljetus; ajourat; kaato; kasaus
English keywords: forest haulage; pulpwood; timber harvesting; fellings; forest work; off-road haulage; strip road; bunching
Abstract | View details | Full text in PDF | Author Info

The aim of the paper was to analyse, using a computer simulation technique, the moving distance of pulpwood bolts when direct felling of trees is used and the bolts are gathered alongside the strip road. According to the results, the average moving distance of bolts depends in a complicated way on the usable part of the stem and the spacing of strip road. As a rule, the differences between moving distances of two-meter bolts weighted and unweighted by bolt volume of various trees is 0–16% when the strip road spacing is 30 m the reason being the fact that the heaviest butt bolts are often more far away from the strip road than the top bolts.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4872, category Article
Matti Kärkkäinen. (1972). Kuusen ja männyn sydänpuuosuudesta. Silva Fennica vol. 6 no. 3 article id 4872. https://doi.org/10.14214/sf.a14679
English title: The proportion of heartwood in Norway spruce (Picea abies) and Scots pine (Pinus sylvestris).
Original keywords: kuusi; kuitupuu; mänty; sydänpuu; läpimitta
English keywords: Norway spruce; Picea abies; Scots pine; diameter; heartwood; pulpwood; Pinus sylvestri
Abstract | View details | Full text in PDF | Author Info

The study deals with the variation in the proportion of heartwood  in Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) both within and between stems as examined on the basis of literature. Special attention is paid to an application, in which on the basis of the diameter of pulpwood bolts, efforts are made to predict the proportion of heartwood in the total volume of bolts. It is shown that the method, even when based on homogenous material of 564 Norway spruce and Scots pine bolts, easily leads to wrong conclusions concerning the proportion of heartwood.

The PDF includes a summary in English.

  • Kärkkäinen, E-mail: mk@mm.unknown (email)
article id 4718, category Article
Ilmo Rinkinen. (1964). Suomen sahateollisuuden jätepuu. Jätepuun käyttöä ja sen edullisuutta koskeva tutkimus. Silva Fennica no. 115 article id 4718. https://doi.org/10.14214/sf.a14277
English title: Waste wood of the Finnish sawmill industry. A study of the use of waste wood and its profitability.
Original keywords: sahateollisuus; jätepuu; sahat; raaka-aine; selluteollisuus; kierrätys
English keywords: recycling; waste wood; sawmills; sawmill industry; raw materia; pulp industry
Abstract | View details | Full text in PDF | Author Info

The purpose of this investigation was to construct a procedure for measuring the profitability of the use of waste wood. The average price a sawmill gets from the waste wood depends, on the amount of use compared with the waste wood output, and on the composition of waste wood. Production of different kinds of waste wood presupposes investments, therefore, the size of a sawmill, in addition to its location, affects the composition. The data was collected by mailing a questionnaire through the central organizations of the sawmill industry in 1959.

The amount of waste wood per standard of sawn wood increases with the size of the sawmill. Because small sawmills cannot generally use or sell their waste wood, they strive at using the raw material effectively. In addition, they produce much rough-edged sawn wood, and sorting is not as strict as at large sawmills. They also leave their sawn wood untrimmed.

Finland’s pulp industry has expanded significantly since 1958. This has increased the need of raw wood, and the demand of sawmill waste. An additional data collected showed that in 1958 there was about 150 and in 1963 about 200 sawmills delivering waste wood to the forest industry. The amount of waste wood used as raw material compared with the total waste wood utilization had increased about 10% during the period. The production of cellulose chips became profitable when the annual output of sawn wood of a sawmill exceeded 1,000-2,000 stds. The size structure of the sawmills affects the regional usage of the waste wood.

The PDF includes a summary in English.

  • Rinkinen, E-mail: ir@mm.unknown (email)
article id 4472, category Article
Pienpuukomitea. (1933). Pienpuukysymys. Silva Fennica no. 31 article id 4472. https://doi.org/10.14214/sf.a9044
English title: The small timber problem.
Original keywords: kuusi; Picea abies; metsänhoito; polttopuu; kuitupuu; pienpuu; puusokeri; puun kaasutus; puun kysyntä
English keywords: Norway spruce; fuel wood; pulp wood; wood sugar; wood gas; wood demand
Abstract | View details | Full text in PDF | Author Info

A Committee was appointed in 1931 to prepare a program to improve the trade of small timber and to develop Finnish fuels and their production. The low demand for small timber is caused by the reduced export of Egyptian balks, and decreased demand of fuel wood that have been replaced by the imported fuels, like coal. At the same time, the supply of small timber has grown significantly due to increased thinnings, and better transport facilities that have made timber more accessible. Also, decreasing demand of large timber has increased the supply of small timber. The demand of small timber concentrates on Norway spruce (Picea abies (L.) H. Karst.). The sales of small timber are crucial from the silvicultural point of view. Selection felling of large timber in the past has reduced the supply of logs and led to surplus of small timber.

The article discusses the uses of small timber and potential new fields, such as wood sugar as fodder or refining wood as fuel. The use of timber should be promoted especially in the domestic industry. The Committee suggests funding for an additional forestry teaching post in the University of Technology, for forest technology and forest economics research in the Forest Research Institute, for research in wood technics, and for follow-up of forest sugar and wood gas fields.

The PDF includes a summary in English.

  • Pienpuukomitea, E-mail: pk@mm.unknown (email)
article id 4470, category Article
Einar Maliniemi. (1933). Päivittäisistä paperipuiden valmistusmääristä eri vuoden aikoina Perä-Pohjolassa. Silva Fennica no. 29 article id 4470. https://doi.org/10.14214/sf.a9042
English title: Seasonal variations of pulpwood harvesting in the northernmost Finland.
Original keywords: kuitupuu; työtehotutkimus; hakkuu; Perä-Pohjola; puutavaranvalmistus; kausityö
English keywords: pulpwood; felling; time and motion study; labour productivity
Abstract | View details | Full text in PDF | Author Info

The fellings of small timber have been expanded from seasonal to full-year operation in many areas. A time and motion study was conducted on the felling of pulpwood in different times of the year in seven felling sites in the northernmost Finland. The work was payed per one pulpwood bolt. The output of a one-man teams was larger than 2-6-man teams. Teams of even numbers were more effective than teams of uneven numbers. One-man teams were more popular during summer. The output was largest during the summer. In the late summer the results decrease, because barking of trees becomes more difficult. Shortening of daylight hours begin to shorten the workdays in the autumn. In December, the average working days are about 6 hours. Snow and low temperatures make logging and barking more difficult during the winter. The output was lowest in January, despite that work days are 1 ½ hours longer than in December. It is concluded that pulpwood fellings should be avoided from December to March 15. If the fellings are necessary, the wage system should be changed more flexible than at present. The size of cutter’s lots should be adjusted so, that work periods are not too short. Sufficiently big lots save time spent on travelling between the sites and villages.

The PDF includes a summary in German.

  • Maliniemi, E-mail: em@mm.unknown (email)

Category : Article

article id 7124, category Article
Viljo Holopainen. (1960). Central marketing of cellulose, with particular reference to brand policy. Acta Forestalia Fennica vol. 73 no. 2 article id 7124. https://doi.org/10.14214/aff.7124
Keywords: Finland; Europe; export; marketing; pulp industry; cellulose; Scandinavia; sales of sellulose; joint selling
Abstract | View details | Full text in PDF | Author Info

Sales of cellulose have been handled in Finland since 1918 on a central marketing system through the Finnish Cellulose Union (Suomen Selluloosayhdistys), which is a joint sales company formed by the enterprises. First part of the paper constitutes the questions of the channels and functions of marketing. The most focal problem is related to the interests of individual producers. The second part concentrates on the brand policy of central marketing.

The small number of producer companies and – for 40 years ago – the existence of relatively few categories and grades on the market have contributed to the birth of central marketing of cellulose in Finland. Central marketing is probably more advantageous for smaller firms and companies less well placed than the biggest concerns. It levels out the status held by the best and the weakest firm in individual marketing and consequently perhaps does not give a top brand the standing it would have in relation to the other brands in individual marketing. Central marketing may have advantages also in regards of general price level and marketing costs.

The marketing system is dependent on the conditions in which it is to be carried out. An example of this is that Scandinavian cellulose producers have fairly good opportunities under the individual marketing system of using the service factor, owing to the good and far-ranging scheduled shipping facilities of the countries. It is probably the different conditions in this country that have made Finland’s cellulose marketing system essentially different from that of the Scandinavian countries.

The PDF includes a summary in Finnish.

  • Holopainen, E-mail: vh@mm.unknown (email)
article id 7122, category Article
Kullervo Kuusela. (1960). Pinotavaraleimikon taksatoriset tunnukset ja niiden vaikutus leimikkoarvioinnin tarkkuuteen. Acta Forestalia Fennica vol. 72 no. 5 article id 7122. https://doi.org/10.14214/aff.7122
English title: Mensurational characteristics of cordwood stock market for felling and their effect on the precision of stock estimation.
Original keywords: kuitupuu; metsänarviointi; kuutiomäärä; koeala; kuitupuuleimikko
English keywords: pulpwood; forest mensuration; methods; sample plots; pulpwood marked for felling
Abstract | View details | Full text in PDF | Author Info

The annual fellings and sales of pulpwood from the State Forests of Finland comprised 4.0–4.6 million m3 in 1955–1959. In order to improve the accuracy of the methods used in estimating the pulpwood stocks marked for felling, a pilot survey of 18 marked stocks was carried out in 1959. The stock area, average plot volume, variation of the plot volumes, size and shape of the plot and the distribution of the trees by diameter classes as factors affecting the precision have been studied in this paper.

The greater the mean volume of a plot the more homogenous is the structure of the marked stock. The same number of plots gives a better relative precision for the south Finnish marked stock than for the north Finnish ones, which are heterogenous and less valuable. Stocks smaller than 50 ha can often be estimated more advantageously by the strip method or visually than by the plot method. The proper size of plot in Southern Finland is 0.02–0.03 ha. In Northern Finland the plots should be larger due to the heterogenous stocks, about 0.05 ha. The shape can be either circular or rectangular. The former may be more practical and reliable in the field. The minimum number of sample trees is considered to be about 200 per 100 sample plots 0.03 ha in size.

The PDF includes a summary in English.

  • Kuusela, E-mail: kk@mm.unknown (email)
article id 7463, category Article
Paavo J. Ollinmaa. (1955). Koivun vetopuun anatomisesta rakenteesta ja ominaisuuksista. Acta Forestalia Fennica vol. 64 no. 3 article id 7463. https://doi.org/10.14214/aff.7463
English title: On the anatomical structure and properties of the tension wood in birch.
Original keywords: koivu; rakenne; selluloosa; sahaus; rauduskoivu; hieskoivu; vetopuu; kemialliset ominaisuudet
English keywords: birch; Betula pendula; Betula pubescens; silver birch; downy birch; sawing; technical properties; structure; tension wood; pulp; chemical properties
Abstract | View details | Full text in PDF | Author Info

The investigation concerns with the strength of the eccentric growth accompanying formation of tension wood in silver birch  (Betula pendula Roth.) and downy birch (Betula pubescens Ehrh.), behaviour of wood in wood-working machines and its macroscopic characteristics, its microscopic and sub-microscopic structure, chemical composition, resistance against certain chemicals, physical properties, and the strength characteristics of wood.

The most detrimental properties of tension wood used in wood working industry are high longitudinal shrinkage, warping, twisting and checking. The wooliness of the cut is unwanted, for instance, in plywood and furniture. In pulp industry tension wood is better raw material than normal wood because it yields more and purer cellulose than normal wood. However, it has poorer strength properties.

The PDF includes a summary in English.

  • Ollinmaa, E-mail: po@mm.unknown (email)
article id 7430, category Article
Veijo Heiskanen. (1954). Paperipuurankojen mittauksen tarkkuudesta Perä-Pohjolassa. Acta Forestalia Fennica vol. 61 no. 18 article id 7430. https://doi.org/10.14214/aff.7430
English title: On the accuracy of measurements of pulpwood boles in Northern Finland.
Original keywords: kuitupuu; tilavuus; paperipuu; mittaus; kuutioimistaulukot; tyvi-latvamittaus
English keywords: pulpwood; volume; wood measurement; volume tables; top measurement
Abstract | View details | Full text in PDF | Author Info

The study examines the accuracy of volume tables for top measurement of pulpwood boles, and that of top measurement in general in Northern Finland. In this method only top diameter and length of the boles are measured, and the volume is obtained from volume tables. The boles have previously been measured in the middle of the bole, but the method is very time consuming in practice.

The result indicates that the form of both Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) varies greatly. A pulpwood parcel, however, contains both rapidly and gently tapering logs, and the average form differences are much smaller. The difference between the real volume and the volume obtained from the volume tables is generally less than 12% and for more than third of the stock less than 4%.

Pine boles from private forests have been somewhat more and spruce boles less rapidly tapering than boles cut from state forests. The significance of the differences is not clear. Also, the boles in the northern part of the investigation area taper more sharply than those in the southern part.
It is concluded that the accuracy of the top measurement should be improved, but this is only theoretically possible by means of special tables and correction coefficients.

The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.
The PDF includes a summary in English.

  • Heiskanen, E-mail: vh@mm.unknown (email)
article id 7419, category Article
Paavo Aro. (1954). On the reasons for differences in the measurements of exported pulpwood. Acta Forestalia Fennica vol. 61 no. 7 article id 7419. https://doi.org/10.14214/aff.7419
Keywords: pulpwood; measurement; export; paper wood
Abstract | View details | Full text in PDF | Author Info

Exported wood is measured at the port in Finland by certified measurers. Wood is paid according to these measuring certificates. However, in many cases the buyer measures the wood again in the country of destination, and gets smaller amounts. This sometimes causes awkward situations.

To examine the phenomenon one lot of pulpwood was measured both in Finland and in the destination country Germany. Several differences were found for the amounts of wood, and the author discussed the possible reasons for these differences.

However, because of the possible scattering in the measurements, several reductions are always made to the measurements. Hence it was proved that the buyer got the amount of wood they paid for. It is clear that the current practices and tools used to measure the amount of wood do not allow for any more accurate measures.     

The PDF contains a summary in Finnish. 

  • Aro, E-mail: pa@mm.unknown (email)
article id 7406, category Article
Jaakko O. Murto. (1951). Mäntypuumme pihka voiteluöljyn raaka-aineena : puunkäyttöopillinen tutkimus. Acta Forestalia Fennica vol. 59 no. 2 article id 7406. https://doi.org/10.14214/aff.7406
English title: Finnish Scots pine resin as raw material for lubricating oil.
Original keywords: mänty; sota-aika; kannot; pihka; voiteluöljy; pihkaöljy; männynpihka; mäntyöljy; sulffaattiselluloosa
English keywords: Pinus sylvestris; Scots pine; resin; lubricating oil; war-time; tall oil; tar wood; sulphate pulp mill
Abstract | View details | Full text in PDF | Author Info

After the Second World War shortage of lubrication oil forced Finland to develop a substitute product that was produced of indigenous materials. This report is an overview of the history of the already terminated lubricating oil industry and it gives a detailed description of lubricating oil production.

The annual lubricating oil consumption in Finland was 15,000 tons before the war, but during the war it decreased to 7-8,000 tons. In 1943 Oy Tervaöljy Ab (Tar Oil Limited) was established with the state of Finland as the main shareholder. It was commissioned to plan and build tar and tar oil plants, and it also transmitted tar from stump wood pyrolyzing plants to oil factories. Two raw materials were used to produce tar oil: tar wood collected from Scots pine (Pinus sylvestris L.) stumps and tall oil, a by-product of sulphate pulp mills. A total of 9,000 tons of lubricating oil substitutes was produced in 1943-1947, 53% of this from sulphate pulp mill by-products and 47% from tar and shale oil.

The PDF includes a summary in English.

  • Murto, E-mail: jm@mm.unknown (email)
article id 7387, category Article
L. Runeberg. (1946). Trade in forest products between Finland and the United States of America. Acta Forestalia Fennica vol. 54 no. 1 article id 7387. https://doi.org/10.14214/aff.7387
Keywords: Finland; forest industry; exports; markets; demand; USA; pulp; America; import; the United States; paper
Abstract | View details | Full text in PDF | Author Info

The purpose of the analysis presented in the article was to form an estimate as to future Finnish-American trade in forest products. The Finnish-American trade, that had its beginning in 1919, has been steadily growing and at the outbreak of the Second World War occupied third place in Finland’s total foreign trade. Over 90% of the Finnish exports consisted of forest industry products, pulp and newsprint being the most important items. The sales associations of the pulp and paper industries made it possible for the industries to gain a footing in the American market.

The production of pulp and most kinds of paper has increased in the USA up to 1942, but production of newsprint has tended to decrease. The timber resources of the country are large, but there is a considerable timber deficit in the northeastern states, therefore, these regions must be the principal aim for a campaign to build up the future market. According to the survey of future need of imports to the USA, more than two million tons of pulp and 2-3 million tons of paper products are needed in the immediate post-war period. The Canadian and Swedish competition will remain at about the same level, but one Finnish advantage, the quality, has disappeared on account of the progress made by research in the USA during the war.

The PDF includes a summary in Finnish.

  • Runeberg, E-mail: lr@mm.unknown (email)
article id 7371, category Article
Einari Wuoti. (1942). Kuusisahapuun teknillisen ja pinokuution välinen suhde sekä sen riippuvaisuus muotoluokasta. Acta Forestalia Fennica vol. 50 no. 18 article id 7371. https://doi.org/10.14214/aff.7371
English title: Relation between technical and piled cubic meter of Norway spruce saw logs and their relation to form class.
Original keywords: kuitupuu; tukkipuu; kuusitukki; puun hinta; kuusisahapuu; tekninen kuutiometri; pinokuutiometri; muotoluokka
English keywords: saw logs; pulpwood; form class; price of timber; wood price; technical cubic meter; piled measure; piled cubic meter
Abstract | View details | Full text in PDF | Author Info

Due to shortage of large logs, sawmill industry has been forced to buy also smaller logs, which also pulp industry uses as a raw material. Sawmills must be careful in the pricing of the logs, because profitability of sawing of timber depends on the size of the logs. These industries use different measures when they buy timber: pulp industry uses piled measure in meters, while saw logs are measured individually in cubic feet. The aim of the study was to develop sets of figures on technical cubic measure of a saw log and its relation to a piled cubic meter from the same log used as pulp wood. In addition, the effect of form class on the measures was studied.

The relation was assessed for trunks that had good, mediocre or unfavourable form class, which distinction is easy to make for a forest worker buying timber. The relations can be used by a buyer of saw logs or pulpwood who need to compare the prices or when the seller of the wood compares the offers.

The PDF includes a summary in German.

  • Wuoti, E-mail: ew@mm.unknown (email)
article id 7364, category Article
V. Pöntynen. (1942). Suomen metsätalouden ja metsäteollisuuden toimintamahdollisuuksista Manner-Euroopan markkinoiden varassa. Acta Forestalia Fennica vol. 50 no. 11 article id 7364. https://doi.org/10.14214/aff.7364
English title: Opportunities of Finnish forestry and forest industry in the market of Continental Europe.
Original keywords: metsätalous; metsäteollisuus; vienti; paperiteollisuus; sahateollisuus; tuonti; selluteollisuus; Eurooppa; vientimarkkinat
English keywords: paper industry; forestry; Europe; forest industry; export; pulp industry; sawmilling industry; import
Abstract | View details | Full text in PDF | Author Info

The article summarizes import and export of timber and manufactured wood products in Europe before the Second World War, and outlines which are the opportunities of import and export after the war. The evaluation is based on statistics of 1936 and 1937. The export balance of Europe was positive; when all the timber assortments were included, Europe exported almost 10 million m3 more timber than it imported. Export and import of round timber were almost in balance, whereas export of paper products was about 12 million m3 larger than import. Consequently, European forest industry reached its magnitude before the war through export overseas. Foreign markets have been important especially for countries like Finland and other Nordic countries.

The war has disturbed the markets. In a scenario where Europe remains a closed sub-area in the global market, there is 10 million m3 excess of timber and wood products. Within Europe, United Kingdom is the greatest importer of timber and manufactured wood products. If UK was excluded from the European market, it would mean a big change in the export and import balance within the area. In 1936 and 1937 the import would have been only 45% and 55%, respectively, of the export if UK is not included in European numbers. If also Russia is excluded from the European sub-area, it would affect especially the export of round wood, sawn timber and plywood. Nordic countries have accounted for about 80% of European paper products export before the war. According to the article, Finnish wood resources do not allow big increase in sawn industry. However, there is potential in increasing demand of pulp in continental Europe in future. In general, Finnish forest industry would have to decrease the production, if the markets would be limited to the European sub-area.

The PDF includes a summary in German.

  • Pöntynen, E-mail: vp@mm.unknown (email)
article id 7346, category Article
Th. Wegelius. (1939). The presence and properties of knots in finnish spruce : investigations concerning the origin and characteristics of branch and knot wood in finnish spruce with particular consideration given to the raw material needs of the paper industry. Acta Forestalia Fennica vol. 48 no. 1 article id 7346. https://doi.org/10.14214/aff.7346
Keywords: Picea abies; pulpwood; quality of wood
Abstract | View details | Full text in PDF | Author Info

The most important characteristics for the quality of round timber is knottiness. Knots decrease the strength of the wood in sawn goods. Knots in pulpwood obstruct the production process of ground pulp and lower the quality. A qualitative classification of saw logs has been suggested, and the abundance of knots could also be used to determine the quality of pulpwood. In this study, visual observations on the preparation of pulpwood in pulp mill were made to observe the quality of the wood. Samples of the wood was collected, and they were divided in five quality classes. To study the influence of age, forest site type and stand on knots, 140 sample trees of Norway spruce (Picea abies (L.) H. Karst.) were analyzed. The article includes detailed analysis of the abundance and position of knots in the stems of spruce, anatomical structure of the knots, microscopic structure of the fibers, and mechanical properties of the branch and knot wood.

  • Wegelius, E-mail: tw@mm.unknown (email)
article id 7335, category Article
V. Pöntynen. (1936). Suomen puunjalostusteollisuus raaka-aineen käyttäjänä vuosina 1925-1935. Acta Forestalia Fennica vol. 45 no. 3 article id 7335. https://doi.org/10.14214/aff.7335
English title: The consumption of wood in forest manufacturing industry in Finland in 1925-1935.
Original keywords: sahateollisuus; selluteollisuus; puun käyttö
English keywords: saw industry; pulp industry
Abstract | View details | Full text in PDF | Author Info

The consumption of wood and the value of the wood in the forest manufacturing industry in 1925‒1935 was studied using the official industrial statistics as the main source of data. The annual wood consumption of sawmills, plywood industry, match production, wood-wool industry, spool production, mechanical pulp mills, sulfite pulp mills and sulfate pulp mills was in average 15.6 million cubic meters, of which 4.0 million m3 was pulpwood, 11 million m3 saw logs and 0.44 million m3 veneer timber. The spool production used 163,200 m3, match production 39,900 m3 and wood-wool production 7,900 m3 of wood. When the wood consumption is at its maximum levels, the fellings cannot be increased sustainably. Thus, the sawing cannot be increased from the present level. The growth of pulp industry has created demand for small timber, and in that industry there is room for expansion.

The PDF includes a summary in German.

  • Pöntynen, E-mail: vp@mm.unknown (email)
article id 7277, category Article
Einari Wuoti. (1933). Kuusipaperipuun kutistumisesta ja kutistumisen osuudesta pinon painumiseen. Acta Forestalia Fennica vol. 39 no. 6 article id 7277. https://doi.org/10.14214/aff.7277
English title: Studies on shrinkage of Norway spruce pulpwood and its effect on sinking of the stacks.
Original keywords: kuitupuu; puukauppa; pino; pinomitta
English keywords: pulpwood; stacked wood; stack; piled wood; measuring of stacked wood
Abstract | View details | Full text in PDF | Author Info

When the volume of the pulpwood was determined from the dimensions of the stack, the practice was to add an agreed percentage to the height of the stack which took account of the sinking of the stack as the wood dried. The stack was piled to the agreed added height, or the percentage was compensated when the stack was delivered to the buyer. The aim of the study was to determine a more accurate percentage to be used in the pulpwood sales.

The dimensions of a stack of Norway spruce (Picea abies (L.) H. Karst) pulpwood and the diameter of each log was measured during the drying. The 223 cm high pile sank by 0.8% to 221 cm, and the stacked cubic meter decreased from 4.46 m3 to 4.42 m3. However, the shrinkage of a solid cubic meter of the wood was 2.8%, markedly more than the sinking of the stack.

The PDF includes a summary in German.

  • Wuoti, E-mail: ew@mm.unknown (email)
article id 7266, category Article
Eino Saari. (1931). Tutkimuksia Suomen puuvanuketeollisuuden raaka-ainekustannuksista. Acta Forestalia Fennica vol. 37 no. 4 article id 7266. https://doi.org/10.14214/aff.7266
English title: Investigations into the costs of raw material in the Finnish pulp industry.
Original keywords: kuitupuu; selluteollisuus; puun hinta; mekaaninen massa; puuhioke; kemiallinen massa
English keywords: pulpwood; pulp industry; mechanical pulp; chemical pulp; wood prices
Abstract | View details | Full text in PDF | Author Info

The article is a review on the wood procurement and cost of pulpwood in the Finnish mechanical and chemical pulp industry in 1922‒1926, based on statistics collected from the members of the Central Association of the Finnish Woodworking Industries (now Finnish Forest Industries), and the series Statistics of Industry and Foreign Trade. Wood trade is carried out by three types of sale: standing sales where the buyer of the wood takes care of fellings and transport (55% of the volume), contracts for the delivery of pulpwood (45% of the volume), and fellings in the own forests of the industry. Norway spruce (Picea abies (L.) H. Karst.) was the most important tree species, and was used almost exclusively especially in the mechanical pulp mills. According to the study, the demand of pulpwood increased markedly during the period. The stumpage prices did, however, not increase accordingly until in 1926. It is assumed that also the supply of wood was high after the World War I.

The PDF includes a summary in English.

  • Saari, E-mail: es@mm.unknown (email)
article id 7265, category Article
V. Pöntynen. (1931). Suomen puunjalostusteollisuuden raaka-aineen käyttö vuosina 1911-29. Acta Forestalia Fennica vol. 37 no. 3 article id 7265. https://doi.org/10.14214/aff.7265
English title: Wood consumption of wood manufacturing industry in Finland in 1911‒1929.
Original keywords: metsäteollisuus; sahateollisuus; selluteollisuus; puun käyttö; puu raaka-aine; vaneriteollisuus; puuhiomo
English keywords: forest industry; wood consumption; pulp industry; sawmilling industry; plywood industry; mechanical pulp
Abstract | View details | Full text in PDF | Author Info

The main source of data was the official industrial statistics in 1911‒1929. The data was complemented with information from other sources, and the figures converted to solid volumes under bark. The wood consumption of wood manufacturing industry in the period varied strongly, being lowest in 1918 (2.2 million m3) and highest in 1927 (18.1 million m3). The wood consumption dropped during the World War I.

The wood manufacturing industry in Finland concentrated on sawmilling industry which has used annually 70‒80% of the wood consumed in the whole wood manufacturing industry. Other sectors of industry using wood were plywood industry, wood-wool industry, spool factories, match industry, mechanical pulpwood industry and pulp industry.

The PDF includes a summary in German.

  • Pöntynen, E-mail: vp@mm.unknown (email)
article id 7511, category Article
Jukka Tyrväinen. (1995). Wood and fiber properties of Norway spruce and its suitability for thermomechanical pulping. Acta Forestalia Fennica no. 249 article id 7511. https://doi.org/10.14214/aff.7511
Keywords: Picea abies; wood properties; pulpwood; fiber properties; thermomechanical pulping; pulp properties
Abstract | View details | Full text in PDF | Author Info

In the first part of the study, the selected wood and fiber properties were investigated in terms of their occurrence and variation in wood, as well as their relevance for thermomechanical pulping process and related end-products. It was concluded that the most important factors were the fiber dimensions, juvenile wood content, and in some cases, the content of heartwood being associated with extremely dry wood with low permeability in spruce. The following pulpwood assortments of which pulping potential was assumed to vary were formed: wood from regeneration cuttings, first-thinnings wood, and sawmill chips.

In the experimental part of the study, the average wood and fibre characteristics and their variation were determined for the raw material groups. Subsequently, each assortment – equalling about 1,500 m3 roundwood – was pulped separately for 24 h period. The properties of obtained newsgrade thermomechanical pulps were then determined.

Thermomechanical pulping (TMP) from sawmill chips had the highest proportion of long fibres, smallest proportion of fines, and had generally the coarsest and longest fibers. TMP from first-thinned wood was the opposite, whereas that from regeneration cuttings fell in between these two. High proportion of dry heartwood in wood originating from regeneration cuttings produced a slightly elevated shives content. However, no differences were found in pulp specific energy consumption. The obtained pulp tear index was clearly the best in TMP made from sawmill chips and poorest in pulp from first-thinned wood, which had generally inferior strength properties. No big differences in any of the strength properties were found between pulp from sawmill residual wood and regeneration cuttings. Pulp optical properties were superior in TMP from first-thinnings. No noticeable differences were found in sheet density, bulk, air permeance or roughness between the three pulps.

The most important wood quality factors were the fibre length, fibre cross-sectional dimensions and percentage juvenile wood. Differences found in the quality of TMP assortments suggest that they could be segregated and pulped separately to obtain specific product characteristics and to minimize unnecessary variation in the raw material and pulp quality.

  • Tyrväinen, E-mail: jt@mm.unknown (email)
article id 7658, category Article
Lauri Hetemäki. (1990). Factor substitution in the Finnish pulp and paper industry. Acta Forestalia Fennica no. 211 article id 7658. https://doi.org/10.14214/aff.7658
Keywords: time series; cointegration; pulp and paper industry; factor demand; cost function
Abstract | View details | Full text in PDF | Author Info

The study examines the factor demands of the Finnish pulp and paper industry. In the theoretical part of the study, factor demand equations are derived using neoclassical production theory. In the empirical part, econometric factor demand model is estimated using annual time-series data for the period 1960–86. The relationship of factor demands and their prices are examined in terms of own price, cross price and substitution elasticities.

It is assumed that the ”representative firm” in the pulp and paper industry is minimizing its costs of production at a given output level. In addition, a number of other assumptions are made which enable the production technology to be represented by a cost function, in which the inputs are capital, labour, energy and raw materials. From the cost function, the factor demand equations, i.e., the cost share equations are derived by applying Shephard’s lemma. The equations are transformed to estimable form using translog approximation for the underlying factor share functions.

The study differs from the previous factor demand studies by applying the error correction model based on the Granger Representation Theorem and the results of the cointegration literature to model the dynamics of the factor demand. This approach provides a statistically consistent method for estimating the long-run static factor demand equations and the corresponding short-run equations. In general, the econometrics of integrated processes (e.g. stationarity and cointegration tests) applied in the present study have not been applied before in factor demand systems models.

The empirical results of the study indicate that the error correction approach can be applied to estimations of the factor demands for the pulp and paper industry. In both industry sectors, the adjustment to short run disequlibrium (price shocks) appears to be fairly rapid. The most significant results of the calculated elasticities are that the factor demands of pulp and paper industries clearly react to changes in factor prices and that there are significant substitution possibilities between the different inputs. The absolute values of the elasticities are, on average, somewhat larger than have been obtained in previous studies.

The PDF includes a summary in Finnish.

  • Hetemäki, E-mail: lh@mm.unknown (email)
article id 7627, category Article
Markku Simula. (1983). Productivity differentials in the Finnish forest industries. Acta Forestalia Fennica no. 180 article id 7627. https://doi.org/10.14214/aff.7627
Keywords: productivity; paper industry; Finland; forest industry; sawmill industry; pulp industry
Abstract | View details | Full text in PDF | Author Info

Improvement of Finnish forest industries’ competitiveness in the world markets through productivity increase as branch and plant level requires the search for appropriate comprehensive productivity indicators and the analysis of factors underlying productivity variations. These were the main objectives of the study. The data was based on the information on individual plants in 1974, obtained from the files of Industrial Statistics in the Central Statistical Office in Finland.

The study uses neoclassical average production functions as the starting point and the theory is expanded to cover factors underlying productivity variation when measured with regard to labour, capital, material input, and total factor input. For the measurement of the latter an index formula is suggested which would not necessarily incorporate neoclassical assumptions as they cannot be assumed valid in the Finnish forest industries. The estimation results of average production functions suggest increasing rate of returns in sawmilling but in pulp and paper production evidence remains inconclusive. The elasticity of substitution is unlikely to be constant and the non-homotheticity assumption cannot be rejected.

The productivity variation is, in general, best explained by a relatively simple model with capital-labour ratio, plant size and output quality as explanatory factors. Further trials with input quality, input price ratio, process characteristics, and the rate of capacity utilization improved the models only marginally in most cases, which may have been partly due to the failure to measure the variables successfully.

The cross-section results are compared with those of an earlier time-series study. The estimation results of average production functions yield somewhat different information in the long and short run. Both cross-section and time-series productivity models illustrate the importance of output level in total productivity.

The PDF includes a summary in Finnish.

  • Simula, E-mail: ms@mm.unknown (email)
article id 7574, category Article
Olavi Isomäki. (1974). Sahateollisuuden kuorintajätteiden käyttömahdollisuudet. Erityisesti käyttö maanparannusaineena ja kasvualustana. Acta Forestalia Fennica no. 140 article id 7574. https://doi.org/10.14214/aff.7574
English title: Using possibilities of barking waste in sawmill industry specially using as a soil improver and substrate for plants.
Original keywords: sahateollisuus; raaka-aine; selluteollisuus; hyötykäyttö; kuorintajäte; maanparannusaine
English keywords: bark; recycling; waste wood; sawmill industry; pulp industry; raw material; soil improvement; barking waste
Abstract | View details | Full text in PDF | Author Info

Residue of the wood is good raw material for pulp and board industries, but the question of the use of barking waste still remains to a great extent unsolved. This research deals with the possibilities to utilize the barking waste of sawmill industry in general and, in particular, its use as a soil improver and substrate for plants. It also explains the industrial manufacturing method of composted bark, bark humus, developed by the author as well as the properties of bark humus and the economy of bark humus and the economy of manufacturing.

The PDF includes a summary in Finnish.

  • Isomäki, E-mail: oi@mm.unknown (email)
article id 7572, category Article
Tauno Kallio, Pekka Tamminen. (1974). Decay of spruce (Picea abies (L.) Karst.) in the Åland Islands. Acta Forestalia Fennica no. 138 article id 7572. https://doi.org/10.14214/aff.7572
Keywords: Norway spruce; Picea abies; timber quality; Heterobasidion annosum; pulpwood; decay; Fomes annosus; Armillaria mellea; injuries; timber trees
Abstract | View details | Full text in PDF | Author Info

In 1972, all Norway spruce (Picea abies (L.) H. Karst.) trees of a minimum 7 cm diameter at breast height growing in the sample plots of the Sixth National Forest Inventory were examined on the main island of Aland, Finland. The soundness of standing trees was estimated by means of external characteristics and increment borer chips. The trees were then felled and measured. They were cut into lengths, and the type and extent of decay were studied.

30% of the trees examined was affected by butt rot, ca. 3% by wound decay. A comparison of the results with those of the Sixth National Forest Inventory justifies the estimate that in Aland 23% of spruce trees exceeding 7 cm in diameter at 1.3 m had butt rot.

The proportion of decayed trees in the cubic volume was 31%. Decayed wood material accounted for 5% of the volume including bark. Butt rot increased towards the mature stands. The reduction in the number of timber trees due to decay was 14.5%, in their volume 21.5%, and in the volume of sulphite pulpwood 12%. The share of sulphate pulpwood increased from 1 to 10%. The total reduction in usable wood was 6.3%. The stumpage price of the trees fell by 10.3%. As the degree of decay increased the increment percentage of the trees decreased. The most common cause of butt rot was Fomes annosus (Heterobasidion annosum) found in 46% of the number of decayed trees. Armillaria mellea was found in 16%. Bacteria were found in 50% of the decayed trees.

The PDF includes a summary in Finnish.

  • Kallio, E-mail: tk@mm.unknown (email)
  • Tamminen, E-mail: pt@mm.unknown

Category : Research article

article id 10539, category Research article
Jaakko Repola, Juha Heikkinen, Jari Lindblad. (2021). Pulpwood green density prediction models and sampling-based calibration. Silva Fennica vol. 55 no. 4 article id 10539. https://doi.org/10.14214/sf.10539
Keywords: pulpwood; conversion factor; green density
Highlights: The developed models provided a realistic description of the observed seasonal variation in pulpwood green density; The model predictions were more reliable than those obtained with current practices.
Abstract | Full text in HTML | Full text in PDF | Author Info

Pulpwood arriving at the mills is mainly measured by weighing. In the loading phase of forwarding and trucking, timber is weighed using scales mounted in the grapple loader. The measured weight of timber is converted into volume using a conversion factor defined as green density (kg m–3). At the mill, the green density factor is determined by sampling measurements, while in connection with weighing with grapple-mounted scales during transportation, fixed green density factors are used. In this study, we developed predictive regression models for the green density of pulpwood. The models were constructed separately by pulpwood assortments: pine (contains mainly Pinus sylvestris L); spruce (mainly Picea abies (L.) Karst.); decayed spruce; birch (mainly Betula pubescens Ehrh. and Betula pendula Roth); and aspen (mainly Populus tremula L.). Study material was composed of the sampling-based measurements at the mills between 2013–2019. The models were specified as linear mixed models with both fixed and random parameters. The fixed effect produced the expected value of green density as a function of delivery week, storage time, and meteorological conditions during storage. The random effects allowed the model calibration by utilizing the previous sampling weight measurements. The model validation showed that the model predictions faithfully reproduced the observed seasonal variation in green density. They were more reliable than those obtained with the current practices. Even the uncalibrated (fixed) predictions had lower relative root mean squared prediction errors than those obtained with the current practices.

  • Repola, Natural Resources Institute Finland (Luke), Natural resources, Ounasjoentie 6, 96200 Rovaniemi, Finland E-mail: jaakko.repola@luke.fi (email)
  • Heikkinen, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: juha.heikkinen@luke.fi
  • Lindblad, Natural Resources Institute Finland (Luke), Natural resources, Latokartanonkaari 9, 00790 Helsinki, Finland E-mail: jari.lindblad@luke.fi
article id 2017, category Research article
Pentti Niemistö, Soili Kojola, Anssi Ahtikoski, Raija Laiho. (2017). From useless thickets to valuable resource? – Financial performance of downy birch management on drained peatlands. Silva Fennica vol. 51 no. 3 article id 2017. https://doi.org/10.14214/sf.2017
Keywords: forest management; Betula pubescens; thinning; energy wood; pulpwood; profitability; final cutting
Highlights: The most profitable management regimes for pulpwood and energy wood production in dense downy birch stands on drained peatlands include no thinnings, but final cutting at the stand age of 40–45 years as whole-tree harvesting, or as integrated harvesting of pulpwood and delimbed energy wood stems about 10 years later depending on applicable harvesting method; A competitive management regime is early precommercial thinning at 4 m dominant height to a density of 2500 stems per hectare and production of pulpwood with a rotation of 55–65 years. Equal profitability is achieved with or without traditional first thinning, which can thus be included for other reasons, for example to improve regeneration of spruce.
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Downy birch (Betula pubescens Ehrh.) stands on drained peatlands are often considered useless because they typically do not yield good-quality sawn timber. However, covering an area of ca. 0.5 million hectares and with total yields of up to 250 m3 ha–1, downy birch stands on peatlands in Finland have a potential for pulpwood and/or energy wood production. We examined the financial performance of alternative management regimes (with or without thinnings, different thinning intensities, several rotation lengths) combined with alternative harvesting methods (pulpwood, energy wood, or integrated, energy wood being delimbed stems or whole trees). We used data from 19 experimental stands, monitored for 20–30 years. For harvesting removals we considered both actual thinning removals and final-cutting removals with alternative timings that were based on the monitoring data. We assessed the profitability as a combination of the net present value of the birch generation and the bare land value of future generations of Norway spruce (Picea abies (L.) Karst.). The most profitable management was growing without thinnings until whole-tree final cutting at the stand age of 40–45 years with an advanced multi-tree harvesting method. In contrast, the standard method in whole-tree final cutting resulted in the lowest profitability, and an integrated method with the energy wood as delimbed stems was the best of the standard methods. Thinnings were unprofitable especially when aiming to produce energy wood, whereas aiming for pulpwood, light precommercial thinning was competitive. Commercial thinning at the traditional “pulpwood stage” had little effect on profitability. The best stand age for final cutting was 40–65 years – earlier for very dense stands and whole-tree energy wood harvesting with advanced method, later for precommercially thinned stands and pulpwood harvesting.

  • Niemistö, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Kampusranta 9 C, 60320 Seinäjoki, Finland E-mail: pentti.niemisto@luke.fi (email)
  • Kojola, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Latokartanonkaari 9, 00790 Helsinki, Finland E-mail: soili.kojola@luke.fi
  • Ahtikoski, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Paavo Havaksentie 3, 90014 University of Oulu, Finland E-mail: anssi.ahtikoski@luke.fi
  • Laiho, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Latokartanonkaari 9, 00790 Helsinki, Finland E-mail: raija.laiho@luke.fi
article id 1599, category Research article
Andrew McEwan, Michal Brink, Raffaele Spinelli. (2017). Factors affecting the productivity and work quality of chain flail delimbing and debarking. Silva Fennica vol. 51 no. 2 article id 1599. https://doi.org/10.14214/sf.1599
Keywords: modeling; plantation; coppice; efficiency; pulpwood; processing
Highlights: Machine productivity averaged 59 m3 ub SMH–1, with a 19% incidence of delay time; Productivity increased 70% if tree volume increased from 0.1 to 0.4 m3 ub; Debarking quality was good for 58% of the trees, medium for 29% and poor for 13%; The more trees in a bunch and the higher BWBS, the lower debarking quality.
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Chain flail delimbing and debarking may improve value recovery from small tree harvests, without renouncing the benefits of multi-tree processing. The technology is mature and capable of excellent performance, which has been documented in many benchmark studies. This paper offers new insights into the relationship between the performance of chain flail delimbing and debarking and such factors as tree volume, load volume, tree form and bark-wood bond strength (BWBS). The study was conducted in Chile, during the commercial harvesting of a Eucalyptus globulus Labill. plantation. In an observational study, researchers collected production data from over 780 work cycles, and work quality data from over 1000 individual trees. The analysis of these data shows that productivity is affected primarily by load volume. Work quality is affected by BWBS and by the number of trees in a load. Work quality degrades with increasing BWBS and tree number, since more trees tend to shield each other. Tree form has no effect on either productivity or work quality. Regression and probability functions are provided, and can be used for predictive purposes when trying to optimize current operations or to prospect the introduction of chain flail technology to new work environments.

  • McEwan, Postgraduate Forest Programme, Faculty of Natural and Agricultural Sciences, University of Pretoria, Private Bag X20 Hatfield, Pretoria, 0028, South Africa E-mail: Andrew.McEwan@nmmu.ac.za
  • Brink, Postgraduate Forest Programme, Faculty of Natural and Agricultural Sciences, University of Pretoria, Private Bag X20 Hatfield, Pretoria, 0028, South Africa E-mail: michal@cmo.co.za
  • Spinelli, CNR IVALSA, Via Madonna del Piano 10, I-50019 Sesto Fiorentino (FI), Italy ORCID http://orcid.org/0000-0001-9545-1004 E-mail: spinelli@ivalsa.cnr.it (email)
article id 1611, category Research article
Ilpo Ervasti. (2016). Wood fiber contents of different materials in the paper industry material chain expressed in roundwood equivalents (RWEs). Silva Fennica vol. 50 no. 4 article id 1611. https://doi.org/10.14214/sf.1611
Keywords: pulpwood; paper production; raw materials; roundwood equivalent (RWE); wood pulp; recycled fiber; recovered paper; material recycling
Highlights: The paper industry material recycling chain consists of different material streams; Consumed paper products form a huge fiber source for industry. However, a reliable measuring system should be developed to quantify these fiber volumes; Converting factors are introduced to quantify the wood fiber contents of different paper industry-related materials of the chain, namely, wood pulp, paper and recovered paper; By using these conversion factors it is possible to convert for example global recovered paper utilization volumes into wood fiber volumes expressed in roundwood equivalents (RWEs).
Abstract | Full text in HTML | Full text in PDF | Author Info

At present, there are no means for reliably comparing the wood fiber contents of different material streams within the paper industry material chain with each other. The aim of this article is to introduce conversion factors that make it possible to quantify the volume of wood expressed in roundwood equivalent (RWE) values for different paper industry-related materials in the material chain. These conversion factors apply to wood pulp, paper, and recovered paper. European data are used in quantifying the paper industry material streams and calculating the RWE conversion factors. The introduced conversion factors can be used to estimate RWE volumes at a global scale. With assumption that paper recycling did not occur and that paper production volume remained unchanged, an additional volume of 666 million m3 RWEs would be required globally per annum to produce 167 million tons of virgin wood pulp to replace 222 million tons of recovered paper utilized by the paper industry in 2010. This volume is approximately the same as 1.6 times the total removal of wood in Europe (EU27), or the total annual removal of wood in the USA, Canada, and Brazil combined.

  • Ervasti, Aalto University, Industrial Engineering and Management, Maarintie 8, 02150 Espoo, Finland E-mail: ilervasti@gmail.com (email)
article id 1054, category Research article
Karin Kolis, Juhana Hiironen, Esa Ärölä, Arvo Vitikainen. (2014). Effects of sale-specific factors on stumpage prices in Finland. Silva Fennica vol. 48 no. 3 article id 1054. https://doi.org/10.14214/sf.1054
Keywords: pulpwood; timber trade; standing timber sales; hedonic price; sawlogs; non-industrial forest owners
Highlights: Data on 4824 individual sales were used to estimate which factors affect stumpage prices; The time of sale, seasonal harvest restrictions, the location and the assortment affected prices; Larger total volumes and shorter forest haulage distances raised unit prices; A higher percentage of the assortment and percentage of sawlogs within the sale corresponded to higher prices.
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Buyers of standing timber take not only the market situation but also the harvest costs into consideration when making purchase offers. In Finland, 85% of all timber is sold as standing timber, but there is little information for forest owners and third parties regarding how differences in harvest costs are reflected in the stumpage prices. This article analyses the relationship between sale-specific factors and stumpage prices in Finland. Data on 4824 standing timber sales between 2008 and 2012 were gathered from five local Forest Management Associations. Regression analyses were run on the stumpage prices (euros m–3) paid for sawlogs and pulpwood. Seasonal harvest restrictions, the volume of the sale and the timber assortment influenced stumpage prices, as did the presence of forest damages. Prices also differed over time and between locations. Furthermore, the forest haulage distance was statistically significant for pulpwood. The results suggest that the size of the individual sales and the composition of assortments affect the income owners earn from their forest. The results can be used to estimate stumpage prices and the monetary impacts on forest owners of procedures such as forest road network planning and land consolidation, as well as for valuation of forests.
  • Kolis, Aalto University, Department of Real Estate, Planning and Geoinformatics, P.O. Box 12200, FI-00076 Aalto, Finland E-mail: karin.kolis@aalto.fi (email)
  • Hiironen, Aalto University, Department of Real Estate, Planning and Geoinformatics, P.O. Box 12200, FI-00076 Aalto, Finland E-mail: juhana.hiironen@aalto.fi
  • Ärölä, National Land Survey of Finland, Production Support Services, P.O. Box 84, FI-00521 Helsinki, Finland E-mail: esa.arola@nls.fi
  • Vitikainen, Aalto University, Department of Real Estate, Planning and Geoinformatics, P.O. Box 12200, FI-00076 Aalto, Finland E-mail: arvo.vitikainen@aalto.fi
article id 1002, category Research article
Pentti Niemistö. (2013). Effect of growing density on biomass and stem volume growth of downy birch stands on peatland in Western and Northern Finland. Silva Fennica vol. 47 no. 4 article id 1002. https://doi.org/10.14214/sf.1002
Keywords: yield; thinning; silviculture; mortality; pulpwood; stand density; crown; energy-wood
Highlights: The thinning response in young downy birch stands was low and the mortality of merchantable stems was tolerable even in dense unthinned thickets during the rotation of 50 years; The production of above-ground woody biomass and stem volume or even the production of pulpwood increased with stand density, with these values being greatest for unthinned or very lightly thinned plots.
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The objective of the study was to ascertain the relationship of thinning intensity of downy birch (Betula pubescens Ehrh.) stands with height, crown, and diameter development as well as pulpwood, stem volume, and biomass increment using long-term (20−30 years) field experiments. Diameter growth of birches increased with thinning intensity during the first 15 years from thinning in all development phases, though after that it did so only for the youngest stands. The thinning response was low. Thinning intensity had no influence on increase in height. In terms of stem volume with bark, the mortality in unthinned stands during the study period was 30–45 m3 ha-1. The mean stem number in unthinned birch thickets fell from 25 000 ha-1 at a dominant height of 7 m to 3000 ha-1 at 18 m. The stem volume increment over the first 15 years was highest (5–6 m3 ha-1 a-1) on the very lightly thinned or unthinned plots, but later there was no significant difference between initial thinning intensities. The maximum above-ground leafless biomass (over 100 Mg ha-1) was achieved on very lightly thinned plots. Also, the total production (including thinning removal) of biomass or stem volume or even the production of pulpwood increased with stand density, with these values being greatest for very lightly thinned or unthinned plots. During 50-year rotation, the highest leafless above-ground biomass production was 2.5 Mg ha-1 a-1 as a mean value from the experiments. The highest mean annual production of pulpwood (d > 6.5 cm) was 3.2 m3 ha-1 a-1, and, in practice, no saw timber or veneer timber was produced, because of the small size and low quality of the stems. A thinning in downy birch stands increased slightly the size of stems to be removed in future cuttings, but with exception for very light thinning it decreased the production of biomass and merchantable wood.
  • Niemistö, Finnish Forest Research Institute, Parkano Unit, FI-39700 Parkano, Finland E-mail: pentti.niemisto@metla.fi (email)
article id 399, category Research article
Torjus F. Bolkesjø. (2005). Projecting pulpwood prices under different assumptions on future capacities in the pulp and paper industry. Silva Fennica vol. 39 no. 1 article id 399. https://doi.org/10.14214/sf.399
Keywords: paper industry; Norway; capacity; partial equilibrium model; pulpwood; prices
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Capacity changes in the pulp and paper industry affect demand for pulpwood and thus pulpwood prices. This paper analyzes the impacts on roundwood prices in Norway of two possible capacity changes (one new machine and one close-down) that currently are high on the agenda in the Norwegian paper industry, and assesses the generality of the results obtained from these case studies. The two cases are implemented exogenously into a regionalized partial equilibrium forest sector model, and the capacity change scenarios are compared with a business as usual scenario assuming no demand shocks. The projected pulpwood prices change significantly in regions near mills where capacity shifts, at least for the close-down case, but only moderately at an aggregated national level. The reduction in prices under the close-down studied is higher than the price increase from the possible capacity increase case. The asymmetric price responses projected for the two case studies are supported by sensitivity analyses on other regions and cases (technologies). For the capacity increase case it is shown that the level of the projected pulpwood price is sensitive to assumptions on base-year prices and transport costs of imported roundwood, but the magnitudes of the price increases projected as a result of increased demand are less affected by these assumptions.
  • Bolkesjø, Norwegian University of Life Sciences, Dept. of Ecology and Natural Resource Management, Høyskoleveien 14, NO-1432 Ås, Norway E-mail: torjus.bolkesjo@umb.no (email)
article id 494, category Research article
Antero Varhimo, Soili Kojola, Timo Penttilä, Raija Laiho. (2003). Quality and yield of pulpwood in drained peatland forests: pulpwood properties of Scots pine in stands of first commercial thinnings. Silva Fennica vol. 37 no. 3 article id 494. https://doi.org/10.14214/sf.494
Keywords: Pinus sylvestris; peatland; thinning; silviculture; pulpwood; fiber; pulping
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The inherent structural dynamics of drained peatland forests may result in a great variation in various wood and fiber properties. We examined variation in fiber and pulp properties i) among stands, ii) among trees within stands, and iii) within trees in young stands dominated by Scots pine (Pinus sylvestris L.). The stands, selected to cover a maximal range of the potential variation, were all at a stage of development where the first commercial thinnings would be feasible. Differences in the processability of the thinning removals were small. In similar kraft cooking conditions, a 5-unit variation in the kappa number of unbleached pulp was observed among the stands. Stand origin had no effect on pulp bleaching. The wood formed prior to drainage had a higher density, shorter fibers, was slightly slower delignified by cooking, and its yield was slightly lower than that of post-drainage wood. These properties, except for high density, are typical for juvenile wood in general, and at stand level they did not correlate with the proportion of pre-drainage wood. When the variation in fiber and pulp properties was broken down into its components, most of it was derived from tree-level in all the cases. On average, the fiber and pulp properties did not differ from those observed for first-thinning pulpwood from upland sites. Consequently, peatland-grown pulpwood may be mixed with other pulpwood in industrial processes. It would probably be best suited as the raw material for pulps with high bonding requirements, e.g. in the top ply of multi-ply board grades or in some specialty grades.
  • Varhimo, KCL, P.O. Box 70, FIN-02151 Espoo, Finland E-mail: antero.varhimo@kcl.fi (email)
  • Kojola, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland E-mail: sk@nn.fi
  • Penttilä, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland E-mail: sp@nn.fi
  • Laiho, Department of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: raija.laiho@helsinki.fi

Category : Research note

article id 470, category Research note
Paula Jylhä, Juha Laitila. (2007). Energy wood and pulpwood harvesting from young stands using a prototype whole-tree bundler. Silva Fennica vol. 41 no. 4 article id 470. https://doi.org/10.14214/sf.470
Keywords: productivity; energy wood; pulpwood; bundling; integrated harvesting; Fixteri
Abstract | View details | Full text in PDF | Author Info
The productivity of cutting and bundling whole trees using the first prototype of a bundle-harvester comprised of a harwarder as the base machine, an accumulating felling head, and a compacting device was studied in three young stands in order to facilitate the further development of the concept. In addition, the removal and its composition were studied as a means of laying the foundations for developing methods for work rating and measurement on delivery. Bundling enables in-depth integration of pulpwood and energy wood procurement. Both energy wood (crown biomass) and pulpwood can be incorporated into the same bundles, and the subsequent separation of these fractions takes place at the debarking phase at the pulpmill. Bundle-harvesting productivities were relatively low (2.8–3.7 m3/E0-h) when compared to current harvesting technology. Improving working techniques, machine structure, and components showed great potential for increasing the efficiency of the concept. The bundles were dimensionally uniform. Their solid volume varied between 0.350 m3 and 0.513 m3, depending on the bundle assortment and stand properties. Integrating energy wood harvesting with pulpwood harvesting increased removal even by 59 per cent.
  • Jylhä, Finnish Forest Research Institute, Kannus Research Unit, P.O. Box 44, FI-69101 Kannus, Finland E-mail: paula.jylha@metla.fi (email)
  • Laitila, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: jl@nn.fi

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