Optimization Study Of Laser Transmission Welding Process Parameters For Thermoplastic Based On Simulation

With the expansion of the plastic application, people have paid more and moreattention to the technique of laser transmission welding thermoplastic course for itsexcellent welding quality、easy manipulation、high efficiency. Laser transmission weldingtechnology has become an irreplaceable way in many manufacturing sectors which need tobe highly sophisticated. However, there are few domestic studies on this research subject,which results in huge gap on theory and industrialization towards abroad. Therefore,starting a research on laser transmission welding of thermoplastic has significanttheoretical significance.Before selecting the overlap welding way for welding polycarbonate, the paper studiedthe thermal behavior of thermoplastic (such as glass temperature、viscous flow traits、heatexpansion) based on the mechanism of plastic laser transmission welding. Using themethod of experiment and numerical simulation to research the welding process andanalyze the results.First of all, get the transparent samples and the absorbed parts which has0.1%blackcarbon concentration by the mounding way, and check out these samples can be used inlaser transmission welding after the transmittance experiment.Then, based on the Box-Behnken Design theory, design the experiment project withfour factors and each one has five levels, take tensile strength and weld width as theresponses. Destructive welding tensile test and microscope snapshot are done after welding.By anglicizing the results and studying the photos of the welding seam, we could find outthe air vent and the thermal decomposition of the material are the immediate causes of thelow welding tensile. The exorbitant laser power or the too low welding speed both maycause the ablation phenomenon happen; the low clamp force and the short cooling time goagainst the samples getting the effective bond on the weld area.At last, the paper has designed the mathematic model and done the optimizationanalysis. By studying the four factors (laser power、welding speed、clamp pressure and the cooling time) interactive influence to the two responses (tensile strength and the weldwidth),we can find out that the power and the welding speed are the saliency factors,appropriately increase the laser power、clamp pressure、cooling time appropriately anddecrease the welding speed is propitious to raise the quality of the weld. From the contrastof the predicted value and the experimental one, the Response Surface Methodology (RSM)is suitable to optimize the technological parameters. The mathematical models’ accuracyhas been proved and the optimum value which predict by the model is also coincide wellwith the real experiments.This study shows that the RSM can make appreciable impact on the processparameters for improving the quality of the welded samples. Moreover, the study also playa guidance for the automated、massive production, and the technical、theoreticalfoundation for reference are given.