The Preparation Of 3D Printing Materials Used In FDM Process By Using Energy Grass As Filler

Today,3D printing(Additional Manufacturing)has become more and more prominent in manufacturing industry.This process allows the customization of parts and products,eliminates the cost of mold opening,and facilitate the manufacture of complex structures.The use of energy grass to prepare 3D printing materials for FDM process can reduce the cost of materials,increase the value of filaments and the texture of printed products,has broad prospects.In this paper,the ball milled biomass,reduce the average particle size of raw materials to below 0.2 mm,so that it can smoothly through the nozzle of the 3D printer,improved the compatibility of biomass and PLA base material.So that the melting temperature of corn stalk is decreasing to 113.8?,reduces the temperature of 3D printing and significantly increases the toughness of the material.The impact strength of the ball milled hybrid poplar composites reached 30.1 ×10-3 MJ/m2,which was 71%higher than the untreated control sample.The average particle size of energy grass after ball milling is smaller(50 ?m)or less,and it has good interface compatibility and fluidity.Among four kinds of energy grasses,silvergrass has great potential in the preparation of 3D printing materials,and its tensile strength,Young's modulus and impact strength are 23.1 MPa,652.9 MPa and 38.67×10-3 MJ/m2 respectively.To explore the influence of biomass pretreatment on the properties of composite materials,three different pretreated thorium were used as composite materials in this paper.It was found that there was only 1.49%of hemicellulose after acid treatment,and the content of lignin after alkali-H2O2 treatment was only 6.13%.Steam explosion can hydrolyze the cellulose and hemicellulose.Experiments have found that the reduction of hemicellulose will increase the tensile strength and Young's modulus of the material,and the reduction of lignin content will increase the flexural strength and flexural modulus of the material.The acid treatment can increase the tensile strength and impact strength of the Silvergrass-Plastic composite by 16.5%and 4.1%respectively,which is a good pretreatment method.By comparing the mechanical strength of the acid-treated silvergrass-plastic composite with that of several wood fibers,it can found that the interfacial compatibility of the Silvergrass-Plastic composite is better.The tensile and the bending performance of the material are comparable.The lignocellulosic composite is relatively poor,but its impact strength(40×10-3 MJ/m2)is 25%higher than that of the PLA filament,which solves the problem of excessive brittleness of the lignocellulose composite material.Finally,in order to realize the high value utilization of various components of energy grass,this paper used NaOH to extract the lignin of the silvergrass,and analyzed the separated lignin alkali and sodium lignin sulfonate separately,and used only lignin to prepare 3D printing.material.It was found that the isolated lignin belongs to HGS type lignin with the molecular weight of 5×104-1.5×105.The lignin sulfonate belongs to the GS type and has smaller molecular weight.Thermogravimetric analysis showed that neither lignin decomposes significantly below 200?.The lignin composite material has strong rigidity,young's modulus and flexural modulus are 901.2 MPa and 1465.7 MPa,respectively,its impact strength is similar to that of several lignocellulosic filaments(WP1,WP2,WP3).It shows that lignin composites have certain potential as 3D materials.The material using sodium lignin sulfonate as a filler is relatively brittle and has poor mechanical strength and is not suitable for 3D printing.The acid-treated silvergrass composites and lignin alkali composites were subjected to fused deposition experiments.It was found that the former had an optimum forming temperature of 170?,and the latter had an optimum forming temperature of 150?.