Research On The Building Formwork Of Bamboo And Plastic Composite Material

Utilizing the fibre of bamboos and polypropylene (PP ) to make the high-performance building formwork of bamboo/plastic composite ,which promotes the development of building formwork industry of our country, lightens the old and useless plastics pollution to the environment, expands the bamboo application, transforms traditional bamboo products industry to improve its added value.In this article , the following four researches are accomplished to discover a suitable technology to manufacture the bamboo-plastic composite of building formwork, which overcomes the drawback( effect of explosion treatment to fiber morphology, the scattering in the plastic melting ,bamboo fibre bad compatible to plastic).1)Study on high-yield pulping of green bamboo with steam explosion process. The result shows that explosion pulp of breaking length up to 3300um and yield up to 80% is obtained by suitable processing condition of pretreatment and steam explosion.2)Study on the compound technique and the performance of bamboo/plastic composite.( i )compairing two processing technology of double-screw extruding machine technology with interal batch mixer technology, Its result shows mixing bamboo fibre ,PP powder, and right dosage of compatible materials in high-speed mixer , pushing and granulating, mould pressing and sample-making, can realize bamboo fibre scattering in plastic melting body and improve bamboo plastic compatibility. It is suitable processing technology for bamboo/plastic composite. (ii)Adopt single factor experimental way to test, investigate bamboo plastic matching , compatible materials dosage two factor's influence on the performance of bamboo/plastic composite. The result shows: increasing bamboo fibre content, bamboo/plastic composite mechanics performance is on the rise, when bamboo fibre charge is 40% flexural strength reaches maximum (raise for the pure polypropylene by 35%); Increase the bamboo fibre, can improve heat resistance of material obviously (material hotout of shape temperature can raise for the base body plastics by 37 C when bamboo fibre charge was 50% );The rise of bamboo fibre can make melt flow rate drop , increase difficulty of processing. The right dosage of compatible materials contributes to improving composite performance, compatible materials charge was 7%, 30% bamboo / PP composite tensile strength raise about 15% , elongation at break raised about 20%.3)Bamboo/plastic compatibility and mechanism analysing. The analysis results by means of DSC and SEM indicate that the compatible material improves the compatibility bamboo fibre and PP really, and raises the strength of forming of the system; When compatible material dosage is right, bamboo fibre can reinforce plastics , make bamboo/plastic composite mechanics performance improve a lot for the base body plastics.4) Study on the building formwork of bamboo/plastic composite. The orthogonal design is adopted to investigate the influence of bamboo-plastic matching, board density , hot pressing temperature and hot pressing time four factors on building formwork. The result indicates that the optional conditions of manufacturing building formwork of bamboo/plastic composite are: the bamboo-plastic matching 5:5, the density 1.0g/cm3, hot pressing temperature 200 C, hot pressing time 15min. the building formwork of bamboo/plastic composite physics mechanics performance exceed " plywood for concrete form " the not high-quality material last standard (GB/17656-1999 ), flexural strength is 31.1Mpa, combine intensity is 4.0Mpa, absorb water thickness is 0.41%, but the elastic amount is on the low side.