Showing papers in "China Wood Industry in 2001"

Composition of Wire Net and Wood Veneer

Abstract: A method introduced in this paper was to insert wire net between wood veneers and then, join them together with adhesives. In this way, property of electromagnetic shield was imparted to wood based materials .The technique for manufacturing the composite was investigated through comparing the effect of different adhesives, different wire nets, different layers of wire nets on property of electromagnetic shield. Laboratory products showed good electromagnetic shield property and qualified glue bonding strength.

Status of Resources and Wood Utilization of Eucalyptus Plantation in China

Abstract: This paper reviews the status of resources and utilization of wood from Eucalyptus plantation in China from the viewpoints of Eucalyptus resources situation, researches on wood properties, processing technologies and potential of market development. Some suggestions for sustainable development of Eucalyptus plantation in China are given.

Preliminary Study on Bamboo Veneer Peeling

Abstract: Based on the experiments of bamboo veneer peeling, the technical requirements and compositive application measures relating on bamboo veneer peeling were discussed and analysed.

Modification on Fast-growing Chinese Fir ——by Hotpressing after Impregnated with UF Resin

Abstract: The fast growing Chinese Fir board was modified by hot pressing after impregnated with urea formaldehyde (UF) resin. The results were as follows: (1) the modulus of rupture (MOR) and modulus of elasticity (MOE) of modified Chinese Fir board were increased on an average by 42% and 17% respectively, the water absorption( WA ) was decreased by 45% and the thickness swelling (TS) was no marked change; (2) the effects of hot pressing pressure on properties of MOR and MOE of board were quite obvious and the impregnating time in UF resin was the most effective factor on properties of water absorption and thickness swelling.

Developing Wood Preservation with Great Strength for the Economical Use of Wood

Abstract: This article introduced the present situation of wood preservation in China, discussed the developing orientation and prospects of China's wood preservation in the beginning of the new century from four aspects as follows:1)Wood preservation of building timber; 2) Wood preservation of the wood from plantation; 3)Prevention of blue stain fungus and moulds on wood and bamboo; 4)Research and development of new preservatives.

Study on Modulus of Elasticity in Bending of Plywood by Vibration Method

Abstract: The dynamic modulus of elasticity ( MOE ) in bending of plywood was measured by tests of flexural vibration, longitudinal transmission and longitudinal resonant vibration. The results indicated that the MOE of plywood by different nondestructive tests were different, but there was a correlation between them.

Study on Shear Modulus of Elasticity of Plywood by Vibration Method

Abstract: A surface wave propagation method was proposed to measure the dynamic shear moduli of plywood for the first time. The testing results of the dynamic shear moduli for plywood measured both by flexural vibration method and surface wave propagation method were different. According to the theoretic analysis, the surface wave propagation method was more suitable for nondestructive testing of dynamic shear moduli of plywood since it could solve the problem especially for measurement of dynamic shear moduli of plywood with 45° grain angle.

Effect of Saw Side Clearance Angle on Cutting Roughness

Abstract: In this paper, the effect of saw side clearance angle and saw cutting amount on surface cutting roughness was analyzed. The relationship between saw side clearance angle and roughness was also studied. Results indicated that the surface roughness would not be effected by saw cutting amount as long as saw side clearance angle wasn't changed. This study may be helpful for developing new type of saws and improving cutting quality and efficiency.

Initiation of Microcomputer Wood Identification

Abstract: The "Microcomputer assisted Wood Identification System WIP 89" was further deve loped into an initiation of automatic identification. A feature image analysis software was developed to automatically make divisions on identification between softwood and hardwood, abrupt and gra dual transition from earlywood to latewood for softwoods and ring porous wood, semi ring porous wood and defuse porous wood for hardwood.

Improvement of Dimensional Stability on Wood Composite Floor

Abstract: The effect of two kinds of paints on 2 ply wood composite floor dimensional stability was studied. The results showed that the floor treated with alkyd paint was better as far as the stability and cost concerned . The result also showed that the appropriate adoption of the paint type and composition would certainly improve the stability and beauty of the product.

Pilot Test of Anti-sapstain and Anti-mold Formulations on Rubberwood

Abstract: The mixture formulation of chlorothalonil emulsion (F1) and mixture of chlorothalonil emulsion and other fungicide (F2) was more effective than F2 or sodium pentachlorophenol (NaPCP) alone in controlling stain and mold of rubberwood ( Hevea brasiliensis ). In pilot test, the sawntimber treated with each formulation of F1/F2 and NaPCP was not infected with stain and mold. In vacuum pressure treatment test, the result indicated that F2 could prevent the treated timber for 12 days from stain and mold except white mold; and the mixture of 0.0094% F1 and 0.018% F2 could keep the treated timber for 15 days from stain and mold in air drying procedure under the above concentrations. The higher concentrations of F1/F2 might prevent the treated timber for longer time from stain and mold.

A Study of Moist Character of Wheat Straw

Abstract: In this study, the surface contact angle among methane diisocyanate (MDI)、urea formaldehyde resin(UF) and different parts of wheat straw were tested,and the surface free energy of wheat straw was reckoned by testing the contact angle between liquid with different surface tensile and wheat straw. The result showed that the surface free energy of wheat straw was low and there was difference in the longitudinal and cross directions of the wheat straw.

Study on the Composite of Wood-synthetic Fiber

Abstract: In this report, by studying the composite of wood synthetic fiber pressed with various ways, the effect of modification of wood fiber and adhesive was investigated. The results showed: wood fiber could take esterified reaction with maleic anhydride and succinic anhydride, thereby the wood surface polarity was decreased. Modified adhesive could be adhered better to the surface of materials with different surface polarity. Thus, the two ways were useful for improving the compositing between wood and synthetic fiber.

Review on Studies for Vertical Density Profile of Wood Composites

Abstract: Vertical Density Profile (VDP) is an important structural characteristic of wood composites and has strong affect on panel properties. Both the main process variables and the technological measures that attributed to VDP forming were discussed. A review on the application of computer modeling for vertical density profile was also presented.

Analysis of Bamboo Surface Roughness by Stylus Method

Abstract: Surface roughness of Moso Bamboo (Phylltachys pubescens) was measured by a fine stylus method and analysed with three surface roughness parameters, which were maximum individual peak to valley height( R y),average roughness( R z) and mean peak to valley( R a). Results showed that the outer surface of bamboo was smoother than the inner part and the surface roughness was closely related to both bamboo age and sanding. Compared with the surface of Munchurian Ash (Fraxinus munchurica) and Beech (Fagus spp.) wood, the surface of outer bamboo was relatively smoother.

Synthesis of Water Solvable Low-molecular Weight Phenol-formaldehyde Resin

Abstract: The phenol formaldehyde (PF) resin samples under 16 different synthesis conditions were measured by gel penetration chromatographic instrument (GPC). The resin quality index and molecular weight was gained. The results showed that if the mole ratio of phenol∶formaldehyde∶NaOH was 1∶2.1∶0.1, synthesis time went beyond 180 min , then the resin's disperse index was smaller and the molecular was well distributed and the spectra peak was stability. The proportion of molecular distribution between 200～400 was 98.3%. Solid content was 49.8%. Free phenol content was 0.18%. Free formaldehyde content was 0.14%. Brominable substance content was 15.5%. Resin viscosity was 8.8 mPa·s . pH value of resin was 9.23.The ability of dissolve in water was beyond 7.5.