Articles containing the keyword 'softwood'
Category : Article
According to the literature, the mechanical strength of the green reaction wood of softwood species (compression wood) is greater than that of normal wood. Drying increases the mechanical strength but less in reaction wood than in normal wood. In particular, the tensile strength along the grain and the impact strength are lower than in normal wood. The compression strength and possibly bending strength are greater, however.
The properties of the reaction wood of hardwood species (tension wood) differ from those of softwoods. When green, all mechanical properties are weaker than those of normal wood. When dried, the tensile strength and impact strength are better and compression strength lower. There is no great difference in the bending strength.
When the higher density of reaction wood is not taken into account and there are no impact forces, the mechanical strength of reaction wood in sawn goods etc. does not differ so much from that of normal wood. The harmful effect of knots, for example, can in practice be much greater.
The PDF includes a summary in English.
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Kärkkäinen,
E-mail:
mk@mm.unknown
- Raivonen, E-mail: mr@mm.unknown
Category : Article
The objectives of the paper were to find out structure of the sawing time when using field circular saws, influence of the different factors on the sawing time and its structure, average sawing time per unit of raw material and sawn goods, and the fundamentals for the creation of an equitable system for the determination of the basis of payment in sawing work. The observations of the time study were made on both a single log and a work period basis. The material was collected using four saws of different brands.
The results showed that the season when the work was done, and top diameter of the logs to be sawn affected the constant times included in the total sawing time and the time used for sawing of center pieces. While the tree species did not affect the constant times, the grade of the logs of different tree species did have effect, especially in winter sawing. The factors affecting the different phases of the work are described in detail. The length of sawing time was longer in the winter than in the summer. The preparatory jobs in sawing required in average 82 cmin per log, and the time increased with increasing top diameter. The actual sawing is the most time-consuming part of the work, it took in average 132 cmin.
The PDF includes a summary in English.
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Granvik,
E-mail:
bg@mm.unknown
The investigation examines export sales of Finnish sawn softwood sales in 1951-1958, concentrating on the volume of the sales. The material was collected from the archives of Finnish Sawmill Owner’s Association and the Finnish Sawmill Control Organization and the annual reports of the former. Correlation analysis was used in assessing the interdependence of the monthly sales volume and the price, and opening sales and the total sales volume of the year.
A slightly negative correlation was seen between the sale price and the monthly sales volume. Goods sold at under average prices are more abundant than goods sold at over average prices. Generally, with a rising price trend, the annual sales volume increased, but with falling prices the situation was reverse. The sales volume has been dependent on the business cycle development of prices. There was positive correlation between the opening sales and the total sales quantity for the year. The sales volume was at its maximum in the period between November and January, and at the minimum between March and September.
The time of the sales made to different countries differed little judged by quarterly statistics. It seems that the major shippers have generally concluded opening sales first. Northern Finnish shippers and the small shippers of Southern Finland have sold proportionately least during the last quarter. In general, the poorer the qualities in question the smaller on an average the proportion of opening sales but the greater the share of clearance sales.
The PDF includes a summary in English.
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Ervasti,
E-mail:
se@mm.unknown
The aim of the investigation was to estimate the changes in the price ratios of different tree species of sawn timber, timber sizes and qualities, the ratios of the prices obtained by different shippers and from different countries, and their changes, especially the trends and business cycles. The data can be utilized in the organization of sawing and the drawing up of the price scales. The price ratios were calculated by taking 100 as the basic quantity and calculating the values for the other quantities accordingly, the values are called price indices. The data is collected from the sales reports in the archives of the Finnish Sawmill Owners’ Association.
Comparing the ratios of the basic prices, the prices of unsorted pine goods by shipper B (the leading marks of Northern Finland), were considerably higher than the others. The North Finnish pine goods are of the best quality in Finland. The price differences between the other shippers were small. The prices of unsorted spruce goods differed very little with different shippers. In some years the basic prices obtained for pine from different countries showed considerable differences although, in the overall view, the differences were small.
In the leading marks of Northern Finland, the differences between pine and spruce prices was greater than the other price differences. The quality of pine logs in Northern Finland is extremely high. During the periods of prosperity, the price difference between pine and spruce was relatively smaller than during depression. With spruce goods, the relative price difference for the qualities is smaller than with pine goods. For the both species the relative price differences diminished with the increase in the basic price. In the broadest sizes of unsorted pine goods, the price difference of the inch class is much bigger than in the small sizes. This is true especially for boards. The relative price difference between boards and battens increased distinctly with the advance in the basic price. A similar, though not as clear change took place in the price ratio of board and 7” sizes. The price differences between battens and boards are much smaller for spruce than for pine. The trends of the price indices of the different sizes show from the middle of 1920s and as far as the 9” u/s pine sizes very gentle, and in regards of the corresponding spruce sizes, a fairly sharp rising tendency.
The PDF includes a summary in English.
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Ervasti,
E-mail:
se@mm.unknown
The objective of the investigation was to study the trends and fluctuations in the composition of sawn goods, changes due to business cycles, and casual fluctuations. The subject is confined to sawn softwood export to Great Britain, the Netherlands, Belgium and France (The North Sea countries) in 1920-1952. The data was based mainly on statistics of the Board of Customs, Series of Foreign Trade, Finnish Sawmill Owner’s Association and the Finnish Official Statistics.
The North Sea countries took 75-85% of the sawn softwood exported from Finland before World War II, and 50-70% of the quantity exported since the war. Sawn softwood export from Finland is almost exclusively long and small-dimension timber. The composition of the export from Finland to the North Sea countries was defined already during the 1900th century, and no big chances were observed even during the period of 1920-1952. The only definite trend was decrease in the proportion of u/s grade.
The PDF includes a summary in English.
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Ervasti,
E-mail:
se@mm.unknown
The purpose of the investigation was to examine the seasonal pattern in Finnish export shipments and export sales of sawn softwood in 1927-1953. Statistics concerning shipments have been obtained from the Board of Customs, and material relating to sales has been provided by the Finnish Sawmill Owner’s Association (now Finnish Sawmills Association). On the basis of original monthly statistics, 13-month moving averages were computed. Finally, a seasonal index was calculated.
According to the results, the export shipments have a fairly apparent seasonal pattern with very low figures from January to April, a peak from June to August, and thereafter a gradual decline up to the end of the year. There are also considerable variations from year to year but in general the exports follow this rhythm. In contrast to export shipments the seasonal pattern of export sales is characterised by significant irregularity. Market developments and speculation play a far greater role than the seasonal factors. Indeed, a seasonal character in export sales can scarcely be discerned.
The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.
The PDF includes a summary in English.
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Holopainen,
E-mail:
vh@mm.unknown
An attempt was made in the study to determine the annual periods available for foliage spraying when cleaning Scots pine (Pinus sylvestris L.) dominated seedling stands. The study was made in nine experimental fields which were established in different parts of Finland. The spraying was applied throughout the growing season by DM, MCPA and Roundup. The results were inventoried one year after the treatments.
The results showed that there were big differences both in the destruction of hardwood sprouts and in the survival of pine seedlings due to the time period of the spraying. Threshold points were observed in the range of effect of DM and MCPA. By means of these it is possible to time the spraying treatments in such a way that there remains only slight damage to pine, but hardwood sprouts are destroyed totally. The results varied with Roundup so much, among other things due to rain, that such threshold points could not be determined. This preparation both had a milder effect on the hardwood seedlings and caused slighter damage to pine than the other preparations.
In Sodankylä in Northern Finland, the pines attained a good resistance to arboricides when the efficient temperature sum of the growing season was 550, but in Punkaharju in Central Finland only when it was 850. The seed provenance of the seedlings had an effect on the resistance. The threshold temperature sums of resistance in pine were on the average 70–74% from the long-term average number of degree days at the origin of the seed. The effect on the hardwood trees grew weaker as the long-term average was filled. Resistance of pine followed with a specific lag the lignification of the shoot and the ceasing of the growth of the needles.
The PDF includes a summary in English.
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Pohtila,
E-mail:
ep@mm.unknown
- Pohjola, E-mail: tp@mm.unknown
Category : Research article
Forest operations involve several different actors. Each actor imposes their own requirements on the harvester in relation to their differing roles in the industry, whether they are concerned with the harvester itself, information, environmental concerns, etc. The manufacturers of harvesters need to meet the requirements imposed by multiple actors, among them logging contractors, whose survival depends on their harvesters. This paper aims to identify the present drivers of product development and describe the roles of the actors who have been identified as those currently affecting the development of harvesters. A multiple-case study of harvester manufacturers was conducted. In total, 4 cases were studied. Each case was comprised of five interviewees: two from each harvesting manufacturer, two logging contractors, and one dealer. Following 20 interviews and 3 validation interviews (with experts from both the industry and academia), the paper concludes that the present drivers of product development of harvesters are legislators, logging contractors, and expert and research organizations. Harvester manufacturers appear to develop harvesters aligned with requirements coming from both logging contractors and legislators. Logging contractors are the primary customers, and they prioritize requirements that reduce cost and improve work environments. Legislators, and expert and research organizations are supporting development in relation to current regulations.
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Gustafsson,
Department of Accounting and Logistics, Linnaeus University, Universitetsplatsen 1, 352 52 Växjö, Sweden
E-mail:
asa.gustafsson@lnu.se
- Johansson, Department of Forestry and Wood Technology, Linnaeus University, 391 82 Kalmar, Sweden E-mail: jimmy.johansson@lnu.se
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Saunders,
Department of Forestry and Natural Resources, Purdue University, 715 State Street, West Lafayette, IN, USA
E-mail:
msaunder@purdue.edu
- Fraver, USFS Northern Research Station, Grand Rapids, MN, USA E-mail: sf@nn.us
- Wagner, School of Forest Resources, University of Maine, Orono, ME, USA E-mail: rgw@nn.us
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Gustafsson,
School of Industrial Engineering (IPS), Växjö University, SE-351 95 Växjö, Sweden
E-mail:
asa.gustafsson@ips.vxu.se
