Study On The Manufacturing Technology And Stability Of Bamboo Floor

With the comprehensive development and utilization of bamboo, the contradiction between supply and demand of China’s wood has been alleviated to a certain extent for recent years. As a new type of building decoration materials, bamboo floor becomes one of the ideal flooring choices because natural and green sense is required everywhere nowadays. The bamboo floor mostly in indoor natural environment use, it may easy appears problems such as wet-expansion deformation or cracking if in the outdoor or indoor damp and hot wait for relatively poor conditions when using, so it can not satisfy the users’ needs. The research of the technology of bamboo floor will bear profound realistic significance, it will develop bamboo floor application fields and use place, solve the technology and application performance problems of related products, at the same time, it also continue to promote bamboo flooring industry progress and the development of rural economy.This paper took bamboo floor of flat compression and bamboo floor of lateral pressure as the main study objects, researched the change of chemical components applying chemical method and Fourier Transformation Infrared Ray (FTIR), at the same time, and also researched the bamboo microstructure applying Scanning Electron Micrograph (SEM). The technology of bamboo impregnating resin and hot-pressing of bamboo floor were researched and analyzed through the orthogonal test, related physical and mechanical performance such as the quantity of bamboo impregnating resin, MOR of bamboo floor, impregnated stripping length and hardness were tested, and the optimum technological factors were obtained after statistical analysis. In the product performance, the paper focused the analysis on the shrinkage and swelling properties and thermal conductivity of bamboo floor, and discussed the differences between bamboo floor and ordinary bamboo floor. The main conclusions of this paper are as follows:(1) After bleaching treatment and carbonization treatment, cellulose content, hemicellulose content, lignin content and all kinds of extraction content of bamboo are reduced. The carbonized bamboo which decline range of main chemical components is higher than bleaching bamboo, the cellulose, hemicellulose, lignin content of carbonized bamboo in the reduction of5.02%,16.86%,6.41%respectively, and the hot water extract reduced10.43%which was the largest drop in the extract. According to the analysis of FTIR, the related group strength of cellulose, hemicellulose and lignin weakened obviously, which explains that bleaching treatment and carbonization treatment will make bamboo cellulose, hemicellulose and lignin happen pyrolysis or oxidative degradation, and influence the physical and mechanical performance of bamboo.(2) Scanning electron microscopy (SEM) known that bamboo is a kind of porous material, which mainly composed of bamboo skin system, basic system and vascular system. The vascular bundle near the outside of bamboo wall was denser, but the basic system was into a smaller number. The vascular bundle form near the inside of bamboo wall was larger and the distribution was sparser, the number of the basic system was more. The form and number of vascular bundle have an effect on moisture absorption of bamboo fiber, and also influence the shrinkage and swelling properties of bamboo floor.(3) Melamine modified urea-formaldehyde resin adhesive (MUF) usually has a better water resistance and heat resistance, the dip pre-treatment of bamboo is helpful to improve the weather resistance of bamboo floor. The research of bamboo impregnation process showed that measures such as reduced the liquid concentration of MUF, improved the temperature of gluing process, extend the dipping time can improve the fluidity and penetration effect of glue, and increase the glue distribution on bamboo fiber surface. The best technological parameters of bamboo impregnation process are25%liquid glue concentration,20min dipping time,35℃dipping temperature.(4) Different technical factors have different effects on physical and mechanical properties of bamboo floor. Hot-pressing pressure has a significant effect on MOR of flat compression bamboo floor. Technical factors have no significant effect on impregnated stripping length, relatively speaking, the influence of hot-pressing pressure is more obvious. The hardness is related to bamboo property and technical factors. In the conditions of this experiment, various technical factors have no significant effects on MOR, impregnated stripping length, hardness of lateral pressure bamboo floor, influence trend which similar to flat compression bamboo floor. According to the result of orthogonal test, the best technological parameters of bamboo floor of flat compression and bamboo floor of lateral pressure are1.8-2.0MPa hot-pressing pressure,15min hot-pressing time and120℃hot-pressing temperature.(5) The shrinking and swelling properties of bamboo floor of flat compression and bamboo floor of lateral pressure imparted strong directional properties. The shrinking and swelling properties of flat compression bamboo floor had great changes on thickness direction, shrinking rate roughly7.33%at wet material to absolute-dry stage in the thickness direction and swelling rate roughly8.83%at absolute-dry to wet material stage. The shrinking and swelling properties of lateral pressure bamboo floor had great changes in width direction, shrinking rate roughly6.86%at wet material to absolute-dry stage in the width direction and swelling rate roughly6.90%at absolute-dry to wet material stage. All of these had the close relationship with assemble pattern, chemical components change and fiber structure of bamboo. But the testing analysis showed that the dimensional stability of bamboo floor was obviously superior to the ordinary bamboo floor.(6) The conclusion included that thermal conductivity and moisture content, thermal conductivity and density, both had significant correlation, with the increase of moisture content and density, the thermal conductivity of flat compression bamboo floor and lateral pressure bamboo floor both were increased, and it were decreased when the moisture content and density were decreased. Test result showed that the thermal conductivity roughly0.111w/m.k-0.112w/m.k of bamboo floor for flat compression and bamboo floor for lateral pressure.