Preparation And Characterization Of Biomass Composites Based On FDM

In order to expand the high-value clean utilization of agricultural and forestry residues and expand the family of 3D printing consumables,based on response surface test design and analysis methods,degradable PLA/wood powder composite wires are prepared by means of mixing and extrusion.The 1.75mm PLA/eucalyptus powder composite wire is prepared,and the 3D printing parameters are optimized through practical application,and the wire can be used commercially.The main work and innovations completed are as follows:(1)By mixing self-made eucalyptus,wheat straw,rice husk powder with a moisture content of 10%-15%and a particle size of<0.15mm with polylactic acid(PLA),it is found that the PLA/eucalyptus powder composite material has the best mechanical properties.(2)The response surface method was used to graft the PLA/eucalyptus powder composite material with polyethylene octene(POE)through the extrusion process.The tensile and flexural strengths of PLA/eucalyptus powder composite material are highly consistent with the predicted values,reaching 31.27MPa and 41.63MPa respectively.The optimal values of the extrusion molding temperature,eucalyptus powder ratio and POE content are:extrusion Temperature 170℃,eucalyptus powder ratio 15.6%,POE content 5.1%.(3)The 1.75mm degradable PLA/eucalyptus powder composite wire prepared by the single-screw extrusion method.After 3D printing practice and analysis,the recommended values of the main process parameters of FDM 3D printing are.obtained:printing temperature is 210℃,printing layer height is 0.3mm,The printing filling rate is 60%,and the printing speed is 30mm·s-1.The appearance quality of ashtrays,flower pots,fixtures and other works printed according to the recommended values of the main process parameters is significantly better than the printed works of the deviation values of the process parameters.(4)With the help of scanning electron microscope,the fracture morphology of the extruded specimens of eucalyptus powder,PLA/eucalyptus powder mixed composite and grafted modified materials was observed and analyzed,and it was found that the ductile fracture characteristics of the fractures of the three specimens were progressive.Trend,the ductile fracture characteristics of the graft-modified PLA/eucalyptus composite extruded specimens are the most obvious.(5)PLA/eucalyptus powder mixed composite material,1.75mm size degradable PLA/eucalyptus powder composite wire and 3D printed specimen materials were subjected to thermogravimetric analysis and infrared spectroscopy.It is found that the bonding interface between PLA and eucalyptus powder has been significantly improved after modification.The mechanical properties and weather resistance of PLA/eucalyptus powder composite wire have been significantly improved,and commercial applications are expected.