摘要:The LFP-86 fire retardant is a light yellow transparent, liquor which contains N and P. Theresult obtained from experiments on treating wood of Fraxinus mandshurica indicates that the oxygen index of LFP-86 fire retardant is 57 and the retardancy of LFP-86 treated wood meets class I according to JIS D 1201, When the intake of LFP-86 fire retardant is over 60kg/m3and temperature up to 1000℃, the rate of weightloss will be about20% after bur ning 3 rains LFP-86 fire retardant has no ability to defend fungi and ter mites attack In impact bending,bonding strengthand hygrosscopicity resistance, treated woods are lower than untreated woods. LFP-86 has no effects on paintability and corrosivity. There are indications that LFP-86 may be used as a fire retardant for indoor timber and woodcrafts.
摘要:The influence of wood extractiveson the hydration and the bending strength of gypsum plaster and gypsum-bonded particleboard was examined under the existence of commercial retarder RETARDAN P Results indicate: 1. wood extractives can retard the hardening of gypsum plaster and gypsum particleboard, and the bonding strength is also declined Wood species and the quality of gypsum also play important roles for the degree of influence; 2. wood extractives can reinforce the retarding effect of RETAR-DAN P. Meantime the setting time of gypsum .particieboard can be predicted by that of gypsum plaster under interaction of both; 3. the bending strength of gypsum particleboard depends on the wood species, but does not evidently on the addition of retarder.
摘要:Under the schedule of steaming and high temperature drying designed, by using traditional chemical analysis and GC, the author has studied the chemical constitutions of Larch (Larix gmelini)samples before and after drying. The results showed that the steaming and high temperature drying to the wood is a combination process of chemical and physical changes The wood undergoes not only such physical changes as diffution of watery, but also a series of chemical changes The acetyl groups in hemicellulose fall off to formulate acetic acid, increasing the acidity of wood, and thus putting the wood under mild weak acid environment The chemical linkages between lignin and hemicelluloses degraded hydrolically, resulting from the acid effect.
关键词:Larch (Larix gmelini);The schedule of steaming and high temperature drying;Lignin Carbohydrate Complex (L.C.C);Hemicellulose;Acetyl group