Уточнить поиск
Результаты 1-2 из 2
Scots pine (Pinus sylvestris L.) stem wood and bark moisture and density influencing factors
2012
Millers, M., Latvia Univ. of Agriculture, Jelgava (Latvia) | Magaznieks, J., Latvia Univ. of Agriculture, Jelgava (Latvia)
Latvia uses average moisture content and density indexes obtained in Russia and European countries; though, these indexes are different, and there is no information about the most suitable one for conditions in Latvia. Research complex on Latvia’s industrially important tree species - Scots pine (Pinus sylvestris L.) stemwood and bark moisture and density changes, depending on influencing factors, is being conducted at Forestry Faculty of Latvian University of Agriculture. The research results on Scots pine, obtained during the year 2011 in the whole territory of Latvia, are outlined in this article. Wood and bark moisture and density were analyzed in 21 sampling plots, arranged in middle aged and cutting-aged reached forest stands, depending on tree age, cutting time and location place in the tree stem. The average moisture content of pine wood mostly depends on heartwood specific weight and age of the tree. With an increase of tree age, average wood moisture content value decreases from 111% (40-year-old trees) to 77% (145-year-old trees). Scots pine heartwood moisture content changes a little during the year: 30– 34% for 71 to 146-year-old trees; and 34-41% for 37–70-year-old trees. Sapwood moisture content is changes from 113% (in the summer) to 130% (in the winter), without any reference to the age of the tree. The average density of oven dry timber obtained from 71–146-year-old trees in the research is 0.501 g cmE-3, whereas in freshly cut condition – 0.848 g cmE-3.
Показать больше [+] Меньше [-]Problems related to the wood drying in Latvian wood processing enterprises
2001
Akerfelds, I. (Latvia Univ. of Agriculture, Jelgava (Latvia). Faculty of Forestry. Dept. of Wood Processing)
A questionnaire related to the wood drying was carried out among wood processing enterprises in Latvia to clarify the main problems and possible differences depending on production capacity and products. Deformation (twist, bow, spring, cupping etc.) during the kiln drying has been identified as the most important problem for all enterprises. Many problems are related to the product area as very often improper drying technology or incorrect drying schedule is used. Others are connected to the organization and control of drying process - optimisation of the drying schedule, energy consumption, kiln control unit, maintenance of measuring equipment, MC measurement, quality control during drying. There is a difference between softwood and hardwood drying in the product and sales area. Considerably more problems are recognized in hardwood drying (hardwood is often used in furniture production and has higher quality demands).
Показать больше [+] Меньше [-]