First, weld formation mechanism
Weld marks from the mold at different positions of the outflow of molten plastic convergence of the convergence of the formation of traces of weld formation is due to the gate out of the melt through the gate after the complex shape of the cavity to reach the convergence of the respective temperature and pressure , The speed is not exactly the same result.
Melts formed when the merging seam meld line and weld line (weld line), the performance of the weld line was significantly better than the weld line.In general, the merging angle greater than 135 degrees to form a weld line, less than 135 degrees When the formation of weld marks.
The performance of the fusion line is obviously better than that of the welding line. The convergence angle has an important influence on the performance of the fusion joint because it affects the degree of fusion, entanglement and diffusion of the molecular chain after welding. The larger the convergence angle is, the better the weld joint performance is.
Figure: Weld marks and weld lines defined
Second, the form of weld marks
Weld marks are the weakest part of the injection molded parts, not only affect the appearance of the product, but also prone to stress concentration, affecting the overall strength of products.
Third, the causes of weld marks and improve the countermeasures
The quality of weld marks and man-machine material method ring and other factors have a direct or indirect relationship, the key is to grasp the main factors that influence, and determine the correct improvement measures.
Weld mark improvement measures in the table below:
