Lfi Long Glass Fiber Reinforced Polyurethane Composite High Speed Milling Technology Was Studied

LFI long glass fiber-reinforced polyurethane composite (Abbreviation LFI polyurethane composite) is an excellent thermosetting composite with the outstanding characteristics like high specific tenacity and high modulus, good wear resistance and Strong corrosion resistance, and fast moulding, which has been widely employed in aerospace, Building material and automobile industries and other fields.In the automobile industry, on account of the limitations of the molding process, LFI long glass fiber-reinforced polyurethane moulded workpiece (Abbreviation LFI Polyurethane molding workpiece) needs secondary processing to meet the demand of the actual assembly. Due to the worse processability of LFI polyurethane composite. During the milling process, the bad rigidity of the workpiece easily makes it vibrate during the milling process. Additionally, the high milling temperatures, significant tool wear and low Efficiency are also the main factors to restrict the development and application of this composite. In order to solve these existing problems, the author conducts the following experiments by trimming LFI long glass fiber-reinforced polyurethane composite with the dashboard:(l)Analyzing the factors affecting the milling of LFI long glass fiber-reinforced polyurethane composite with the dashboard, and designing proper test programs:1) The reinforced fiber glass in the composite has high intensity and hardness. However, the milling of thick materials needs great work, which exerts large impact on the tool;2) The LFI long glass fiber-reinforced polyurethane composite has low thermal conductivity. Hence, it often transfers heat through the tool, which accelerates the tool wear;3) The compound ABS epidermis on the dashboard surface has low melting point; therefore, it melts easily and stick to the tool which has adverse effect on chip removal.(2)Based on single factor experiment, the paper uses two different milling cutter to down cut and dry mill the LFI Polyurethane molding workpiece. The test shows that the milling depth and the feeding speed are the main factors affecting the milling force, but their effect on milling temperature is relatively small. Besides, milling speed greatly influences the milling temperature and the tool life, while exerts relatively unobvious impact on milling force.(3)According to the results of experiments, this paper finds out the law of the milling parameters affecting the milling force, the milling temperature, and the tool life. Through fitting, the paper obtains empirical formula of milling force and milling temperature. What’s more, this paper makes suggestions about the tool selection and optimizes the milling parameters to improve processing efficiency of LFI polyurethane composite and lengthen the tool life. After all, this paper provides theoretical bases and technical guidance for practical processing.