Injection molding machine screw barrel hardware problems

    If the screw slippage due to equipment not process settings causes the screw and barrel wear might be the culprit. Resin melt in the transition section, and stick to the barrel wall, like the feed zone. When the screw rotates, it will melt cut down and transported to the front. If the screw and barrel wear, the screw would be difficult to effectively materials delivered to the front end. If you are unsure whether by wear and tear, can measure the width of the gap between the screw and barrel, Once the tolerance of non-compliance, should its implementation replaced or repaired.

    Screw design, in particular the compression ratio design in the plasticizing plays an important role. The feed zone is too short, the compression ratio is too small, will result in reduced throughput and screw slippage. The resin suppliers will recommend the best compression ratio of its material.

    Cause screw slippage may be due to non-return valve (check valve) is not working properly. When the screw rotation ready for injection, the retaining ring should be located in the front-end (open position), connecting the convex buckle and snap ring frame. If the collar is in the end (i.e., closed position), or in the middle of the frame of the tail and the collar, then the polymer melt it will be difficult to pass through this gap. If you found a problem with the retaining ring, and should be replaced.

    In addition, a resin feed hopper may also be one of the factors that cause the screw to slip. Proper design of the hopper is homogeneous charge, but often overlooked. With fast compression section (ie square hopper suddenly tightened at the bottom) is more suitable for processing of the raw meal, but not suitable for processing recycled materials. Since the recycled material of broad particle size distribution, and therefore affect the uniformity of the feed, which means that the screw can not convey melt uniformly at the same pressure will eventually lead to slipping. To solve this problem, the compression section (i.e., circular hopper in the bottom of the tapered gradually shrink), to handle a wide particle size distribution of material to be used with gradient.