摘要:A test on the strength of rubberwood showed that rubberwood is almost equal to Chinese fir in some physical properties such as strength, MOE of bending and compression parellel to grain. The relation between the percentage of knots and the reduction in strength of rubberwood were tested as well. The result showed that the relation between them is linear.
摘要:The developed timber kiln model DJQ-1 has a large axial fan which is placed at the end of the stack and forms a horizontal and reverse air flow. The kiln house is of steel and aluminium constructure, which has been proven to have good properties in corrosion resistance. Comparing to the brick and concrete plant, it offers low drying cost, occupies a little area and could be moved easily if necessary. It is suitable for small and medium workshops and factories that have small and medium demands for sawntimber supplied with all species. It is also suitable for high-temperature drying.
摘要:The effects of ammonium polyphosphate (APP) as fire retardant chemical for wood on strength, paintability, corrosivity and toxicity of wood were investigated. The results indicate that bending strength and compression strength parallel to grain of APP treated wood are lower (average 6.25-8.25%) than untreated wood. APP has no effects on paintability, corrosivity and toxicity.
摘要:The gypsum bonded particleboard is a new kind of building material. The object of this paper is to study the possibility of making gypsum particleboard with cotton stalk using the semi-dry method.The results show that although the cold water extractive of cotton stalk retards the setting of gypsum, the setting characteristic of gypsum is changeable and can also be controlled by adding certain chemical accelerator or retarder. The influences of some production parameters were also investigated on the properties of the board.The main production parameters would be suggested:1. Density of the board: <1.2 g/cm~3.2. The ratio of cotton stalk and gypsum: <0.25 (by weight).3. The ratio of water and gypsum: 0.40 (by weight).
摘要:<正> 前言暴马丁香(Syringa reticulata(Blume)Hara var mandshurica(Maxim.)Hara)别名暴马子、白丁香,属于木犀科丁香属,多为小乔木[2、3]分布于我国东北、内蒙古、河北、河南、山西、陕西、甘肃等地。木材质地坚硬、细致、纹理美观、耐潮湿、耐腐朽。可做建筑、细木工及其它木制品,如茶叶筒、食品贮箱等;花可提取芳香油;种子可提取淀粉;树干和树皮可提取镇咳、平喘药物。本文仅对其木材的天然耐腐性及其内含物的化学组份进行初步研究,为合理利用暴马丁香提供科学依据。