Research On The Manufacturing Process Of Bamboo Sandwich-boards

With the continuous improvement of economic level and the change of people’s lives concept, human’s demand for wood and wood products continues to rise; However, due to the reduction of forest resources around the world, the contradiction between supply and demand becomes increasingly prominent. For its wide distribution, short growth cycle, good material and other characteristics, bamboo becomes the first choice as supplementary materials of wood. China’s bamboo resources are relatively abundant with yield and area being the first in the world. Vigorous development of the use of bamboo resources is one of the effective ways to ease the contradiction between timber supply and demand in China. Development and production of bamboo composite materials is an effective way to make full use of bamboo resources. It not only can ease the contradiction between supply and demand of timber, reduce forest cutting and foreign exchange expenditure, but also can create good economic returns for the enterprise and the state, provide jobs for some regions, increase income for the farmers, create good social benefits. Besides, it can protect the natural environment and promote sustainable development of the forestry to create good ecological benefits. Based on the experience of wood composite materials from home and abroad, taking veneer and bamboo beam as the main objects, this study aims to develop a new type of bamboo compound materials-bamboo sandwich boards (bamboo composite LVL), used in flooring, furniture, countertops, engineering, construction structural materials and other fields.By morphological image analysis system using microbial electron microscopy, the study tested and compared the bamboo fiber morphology of three kinds of bamboos with minor diameter and found that they can be used as raw materials of bamboo sandwich boards. Refer to the manufacturing process of LVL, bamboo sandwich boards were prepared and its performance was tested. It also analyzed bamboo species, veneer species, adhesives and the influence of the irradiation processing to raw materials on the performance of bamboo sandwich boards and studied the manufacturing process of bamboo sandwich boards. Through the experiment the following conclusions were drawn:1. Wood veneer and bamboo beam were assembled in accordance with the way of LVL, taking melamine resins and urea-formaldehyde resin as adhesives. It is feasible to prepare bamboo sandwich boards by hot-pressing.2. The moisture content of bamboo sandwich boards ranges from6.7%to9.4%in line with the technical requirements of man-made board process technology. The specimens with veneer of Eucalyptus saligne and Phyllostachys bammusoides have higher moisture content.3. The bonding strength of specimens ranges between0.52to1.96MPa and is significantly affected by bamboo/wood unit, the pretreatment of materials, adhesives and other factors. The bonding strength of the specimens in Homalium foetidum combined with Oligostachyum lubricum or Phyllostachys bammusoides is higher. Raw material pretreatment can enhance the bonding strength.4. The MOE of bamboo sandwich boards is between12.62and17.20GP, which is significantly affected by wood, veneer, adhesive and radiation processing.5. The MOR of specimen is between85.41and151.24MPa. Bamboo, veneer, adhesive connect and the irradiation treatment have significantly influence on the MOR of bamboo sandwich boards with significantly different influence of different factors.6. Except for a few serious stripping materials, most showed good agglutination performance.7. Under this experimental conditions, the best manufacturing process of bamboo sandwich boards are:P=1.3MPa, T=120℃,(pressing time) t=4min, the60Co-γ irradiation of100KGy dose on Homalium foetidum, Oligostachyum lubricum, UF and assemble according to the way of LVL.8. The performance index under the best preparation conditions are as follows: themoisture content being7.5%,bonding strength being2.59MPa, MOR being14.61GMPa,MOR being151.24MPa and perfect agglutination performance.