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

Laser direct marking technology has many advantages, such as high efficiency, non-pollution, and high recognition rate. It has been widely used in product identification and control and so on. With the requirements of timber industry and information technology, automatic identification of timber product identification is particularly urgent. Specific material characteristics of wood are ideal for laser direct marking bar code technology. This paper has done the following research:Laser marking has some destructive influences on wood surface. Through experiments, it is found that laser power, scanning speed, line spacing are the main factors affecting the surface of the wood bar code depth. Though control variety method, the influence of laser parameters and timber characteristics on marking depth is studied. Then a anticipation model of laser marking depth on wood surface was established, and the feasibility and accuracy of the model was verified.The changing rule of contrast towards laser parameters on wood surface was studied. Single-variable control method and orthogonal test were used in the experiment. Contrast curve and ideal combination of laser parameters of barcode were obtained.The important influencing factors on barcode readability were analyzed. And effective methods on increasing the identification rate of were proposed. Some barcodes can’t be read because of the high carbonation level. This problem can be solved by bleaching the wood after marking barcodes. Some barcodes can’t be read because of the low contrast caused by darker color of the wood. Changing the gradation of the ways can be used to improve the contrast of the bar code. Finally, experimental analysis of the impact of the size of the bar code reader, and has been the minimum size.Use central composite design and response surface method to influence the quality of the bar code marking contrast and depth effect variables, and based on second order nonlinear regression models were fitted to various process parameters to obtain three sets of laser parameters and effects over the variables Finally, by comparing the measured and predicted values obtained in experiments to verify the accuracy of the model.Results of this study for laser marking dimensional bar code technology application and development in the timber industry has important practical significance for direct laser marking of other non-metallic materials also has a certain significance.