Study On Preparation And Application Of Bamboo Powder Self-binding Forming Sheet For Household Use

The use of moso bamboo for the preparation of various types of panels usually requires the use of adhesives,but the application of adhesives usually brings problems such as the emission of harmful substances,while the use of bamboo self-bonding molding technology for the preparation of non-adhesive panels is not only environmentally friendly,but also easier to achieve recycling and natural degradation.Bamboo self-combining technology is a technology to produce glue-free panels by processing bamboo into certain units and directly using its own chemical composition to form self-combination without adding any adhesive.In this paper,we use mechanically crushed bamboo powder as raw material,and make bamboo powder self-bonded forming board through hot-in hot-out process.We study the effects of bamboo age,particle size ratio,moisture content,hot pressing temperature and board density on the surface morphology,physical properties,mechanical properties and chemical composition of bamboo powder self-bonded forming board,and get the best preparation process of bamboo powder self-bonded forming board,and use ink-jet printing technology to print on the surface of bamboo powder self-bonded forming board.The decoration is used as interior decorative material to explore the application of bamboo powder self-bonded forming panels in the home.The main findings are as follows:（1）The bamboo age,particle size ratio and moisture content were used as the influencing factors in the orthogonal test to optimize the best combination of raw materials.The orthogonal test of L₉（3⁴）was used to study the effects of three factors on the physical and mechanical properties of the bamboo powder self-bonded formed boards,and finally it was concluded that the water content had the greatest effect on the bamboo powder self-bonded formed boards,and the final combination was optimized with 3-year-old moso bamboo,particle size of 60 mesh or more,and the best physical and mechanical properties of the boards prepared by bamboo powder with 60%water content,with a water absorption thickness expansion rate of 14.5%and an internal bonding strength of 0.44 MPa.The thickness expansion rate of water absorption was 14.5%and the internal bond strength was 0.44MPa.（2）The effects of water content on the surface morphology,physical and mechanical properties,microscopic morphology and chemical composition of the bamboo powder self-bonded formed sheets were investigated.When the water content increased,the physical and mechanical properties of the boards first rose and then decreased.When the water content of bamboo powder was 40%,the water absorption thickness expansion rate of the boards was 13.0%and the internal bond strength was 0.47 MPa.When the moisture content of bamboo powder was lower than 40%,no suitable moisture could be provided,the degradation of cellulose and hemicellulose in bamboo powder became lower,the softening temperature of lignin decreased insignificantly,and the softening degree of bamboo fibers and thin-walled cells decreased,which led to the reduction of the embeddedness of bamboo powder with each other and the physical and mechanical properties decreased.When the moisture content is higher than 40%,during the hot-pressing process,the drainage time increases,the thermal conductivity to the core layer decreases,the softening time becomes shorter,the physical and mechanical properties also decrease,and the color change of the surface of the board is not obvious.（3）The effect of hot-pressing temperature on the surface morphology,microscopic morphology,physical and mechanical properties and chemical composition of the bamboo powder self-bonded formed sheets was investigated significantly.As the temperature increased,the physical and mechanical properties of the sheets also gradually increased,and when the hot-pressing temperature reached 220°C,the absorbing thickness expansion rate of the sheets was 9.9%and the internal bonding strength was 0.56 MPa.As the hot-pressing temperature increased,the thermal conductivity toward the core layer increased during the hot pressing process,which led to an increase in the drainage rate,the degree of softening and plasticization time of the bamboo powder,which enabled the bamboo fibers and thin-walled cells to be fully softened.At the same time,the chemical composition can also be degraded more,so that better physical and mechanical properties can be obtained.However,since the surface color of the bamboo powder self-bonded forming sheet is darker at 220°C and it is more difficult to be applied in actual production,the best performance of the bamboo powder self-bonded forming sheet prepared at 200°C was concluded considering the basic performance,process cost,and product aesthetics.（4）The effects of panel density on the surface morphology,microscopic morphology,and physical and mechanical properties of bamboo powder self-bonded formed panels were investigated.With the increase of density,the compression ratio of bamboo powder per unit volume increased,the physical deformation of bamboo fibers and thin-walled cells increased,the bond between bamboo powder was denser,the surface of bamboo powder self-bonded formed sheets was smoother,and the physical and mechanical properties of bamboo powder self-bonded formed sheets improved.The physical and mechanical properties of bamboo powder are also gradually improved.However,the increase of density has no obvious effect on the surface color and chemical composition of the board.（5）The best combination of bamboo powder through process optimization is:3-year-old moso bamboo,particle size of 60 mesh or more,moisture content of 40%;hot pressing temperature of200℃,the board density of 1.0 g/cm³.in this process the bamboo powder self-bonding molding board water absorption thickness expansion rate and internal bonding strength of 12.8%（<14.0%）and 0.71 MPa（>0.60 MPa）,respectively.All of them meet the requirements of GB/T 11718-2009"MDF"for the performance of common type MDF used in wet condition.The bamboo powder self-adhesive forming board was used as the substrate to prepare interior decorative panels using VU ink-jet printing technology.Compared with wood fiberboard,linden wood plywood and bamboo composite,the adhesion of bamboo powder self-adhesive forming board was weaker than linden wood plywood,but better than commercially available wood fiberboard and bamboo composite.