Research Of Using Laser Direct Marking Two-Dimensional Bar Code Technology On PVC

Nowadays, laser direct marking has replaced the traditional carving methods in a great degree, becoming an important way in the future information tracking. PVC material printing process is complex, laser direct marking is very suitable for this kind of material surface. This topic from process parameters and poor barcode image processing two aspects, the following research work has been done:Studied the barcode depth relations with power, scanning speed. From the point of pulse energy, the engraving depth is deduced and through the experiment to determine the relation between the powen scanning speed and depth to modify the model. Statisticsing the recognition time for different depth of barcodes, get the depth range of recognition time is shorter, determine the scope of the operating parameters of the laser.Selecting contrast and print growth as the barcode image evaluation index. Control variable method is used to study the relationship between four parameters (scanning speed, line spacing, partial focal distance) which affecting the quality of machining and evaluation index. Each laser parameters take 5 levels.Using the method of surface effect to design 30 experiments. By contrast, the X and Y direction of print growth as the evaluation index, using the second order nonlinear model to simulate model of various process parameters, and then optimized the four parameters, finally 5 sets of the optimized process parameters were determined. On this basis, through researched the relationship between mechanics properties of the pipe and the depth of barcode to determine the optimal parameters combination.Choosing a reasonable method to deal with the noise of barcode.For different quality of barcode image choosing a reasonable binarization method.Using image enhancement technology to repair the surface scratches. For seriously damaged barcodes, by image enhancement technology completed information repair.The researching finding of this thesis has an important effect for the application of laser marking 2D-barcodes on the PVC,with some instructions on the other non-metallic.