| China has abundant timber resources of Ginkgo wood which is a very important economic tree species. At present, the utilization of Ginkgo wood is not high, and there is great potential for industrial utilization. The use of Ginkgo wood including physical and chemical properties of Ginkgo branches, the research and development of high additional value of functional wood composite material is scientific and rational use of a major aspect of Ginkgo wood. The Ginkgo branches as the main raw materials, systematic study of the Ginkgo branches preservative, Ginkgo extruded tubular particleboard production technology and elastic properties, multi function of(anti-corrosion, mildew, thermal insulation, sound insulation) Ginkgo extruded tubular particleboard composite wall in modern timber structure building application etc. The main research contents and conclusions are as follows:Firstly, take the Soxhlet extraction method for extraction experiment of Ginkgo branches, bacteriostatic effect of chloroform extract ingredients. The ASE350 accelerated solvent extraction apparatus of Ginkgo branches of the extraction experiment, by gas phase chromatography-mass spectrometry(GC-MS) combined with technology analysis identified the extract of compounds, and determination of the flavonoids content in many parts of the Ginkgo tree. The results show that there are more than 30 compounding ingredients in the extraction, Among them, the alkane compounds accounted for about 8%, alcohols accounted for about 11%, ketones accounted for about 39%, heterocyclic amide accounts for about 2%, sterols accounted for about 9%, sesamin accounted for 5.72%. In addition, the structure also comprises 16% naphthalene compounds. Except alkane have stable structure non-intense reactive property and have not inhibitory fuction against the cell growth with wide bactericidal activity. Some of other component(account for more than 91%) have the inhibitory function against the cell growth with the wide bactericidal activity. Above mentioned function formed chimical mechanism of inhibitory function against the cell growth with wide bactericidal activity of Ginkgo branches. The flavonoid content in different parts of the tree is different. The root has the lowest content, the branches have more and the highest part is the leaves. The results are compliance with the plant biosynthesis laws.The extruded tubular particleboard were fabricated with Ginkgo branches using extruded technology(5% resin content, 160 ℃ extruded temperature and 0.35 m/min extruded speed). The Ginkgo extruded tubular particleboard had good physical and mechanical properties, which the density was 0.33 g/cm3, moisture content was 10%, the modulus of rupture along the length of the board was 1.0 MPa, and perpendicular to the length of the board was 0.6 MPa. The modulus of elasticity along the length was 295 MPa, perpendicular to the legnth was 85 MPa. The formaldehyde emission was 9 mg/100 g. At the same time, the extruded tubular particleboard rectangular coordinate system was build, and the elastic properties of extruded tubular particleboard was also measured and analyzed in this thesis. The results showed that the modulus of elasticity alonge the length direction far less than those in the thickness and width direction. The poisson’s ratio, e.g. μxy and μxz, is the least in the six poisson’s ratios. The elastic properties of extruded tubular particleboard less than those of normal particleboard. The extruded tubular particleboard could been seemed as transversely isotropic materials, and the cross section perpendicular to the length could been seemed as transversely isotropy section.The anti-mold and anticorrosive performances of Ginkgo branches and Ginkgo extrued tubular particleboard were evaluated systematacially in this study. The Penicillium sp., Rhizopus sp. and Aspergillus sp. were chosen as the mold to test the anti-mold performance of Ginkgo branches, Pine and Poplar. The Coriolus versioolor(L.ex Fr.)Quel., Lenzites acuta Berk, and Gloeophyll um trabeum(Pers.:Fr.Murr.) were used as the wood-destroying fungi to evaluate the anticorrosive performances of Ginkgo branches, populus tomentosa, Ginkgo extrued tubular particleboard and mixed wood species extrued particleboard.Short period(two weeks) bacteria screening test was used to choose the most several seriously damage bacterials. And then, the picked out bacterials were used to do the long term(12 weeks) anticorrosive test of the Ginkgo branches and the particleboard. The results show that the Ginkgo branches has the best anticorrosive performance. The infection ability of Aspergillus sp. is stronger than Penicillium sp. and Rhizopus sp. The weight loss of Lenzites acuta Berk in Ginkgo branches was the highest in the short period bacteria screening test. This paper established the Ginkgo branch preservative performance prediction model, Ginkgo branch, Ginkgo extrued tubular particleboard corrosion testing time and weight retention rate between the exponential relationship, weight retention test value and predictive value of the relative error is very small.Then the Ginkgo extruded tubular particleboard was innovatively applied in the manufacture of the composite walls in the wood construction with three different air layer thickness(0 mm, 23 mm and 74 mm). The heat and sound insulation performance of the composite walls have been studied here. The results show that the thermal resistance of the composite walls increased with the air layer thickness when it is lower than 74 mm and the composite wall with 23 mm air layer thickness has the best economical performance. In the insulation of low and high frequency sounds, the Ginkgo extruded tubular particleboard is better than the rockwool. The sound insulation performance was improved by adding the number of the particleboard, but it was not linearly improved. For the light frame wood construction, 2 × 4 system walls with single row studs, when the filling thickness of sound insulation materials and the cavity thickness are the same, the composite wall has the best sound insulation performance.At last, the finite element model of the composite walls produced by the Ginkgo extrud-ed tubular particleboard has been established to study the thermal insulation performance. When air layer thickness to a certain extent, the internal air layer form convection, thermal resistance of the role in the air layer is reduced greatly. The air layer thickness of the composite walls was especially considered and the impact mechanism was studied. |
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