When the injection screw compressive material difficulties in charging port, or along the barrel length can not form a sufficient adhesion to the transportation of materials, then screw slippage occurs. In the pre-plastic screw stage rotary screw conveying material along the direction of the screw in the machine barrel and back accumulated when the material ready for the next injection, screw slippage will occur. If the screw pre-plastic phase starts to slip, then continue to rotate the screw, axial screw stop the Games. Usually screw slippage will cause degradation of the material occurs prior to injection, there will be a short shot, to extend the processing cycle and other product quality problems.
　　Causes include screw slipping back pressure is too high, the second half of the barrel too hot or too cold, or screw barrel wear, the screw feed zone screw groove is too shallow, improper design of the hopper, hopper blockage or material shortage, wet resin, the resin lubricant content is too high, the material particle size is too small, the resin used in cutting poor shape or renewable materials.

　　Influence of Process Parameters
　　After the barrel section is usually caused by low temperature injection screw slippage of the main reasons. Injection molding machine barrel is divided into three sections, the feed section in the rear, forming a layer of molten material in a thin layer of polymer is heated during compression. Molten layer attached to the barrel. Without this thin, it is difficult to transport the pellets forward.
　　Material within the feed zone must be heated to the critical temperature, the molten layer to produce a key. However, often the material in the barrel is too short residence time of the polymer can not reach that temperature. This occurs because the device may be too small, the corresponding configuration smaller barrel and screw caused. The residence time is too short could easily lead to polymer melt or inadequate mixing, which will cause screw slippage or stall.
　　Two simple method for handling the problem appears now be described. From the beginning of the end of the barrel added a small amount of cleaning materials, and check the melting temperature. Dongguan Huahong brand if the residence time is short, it will be lower than the melting temperature of the barrel temperature setpoint. The second method is to observe the molded article, if you find like marble stripes, black spots or streaks of light, it shows that the material in the machine barrel are not well kneaded.
　　One screw slippage occurs is to try to solve, gradually raise the temperature of the feed zone, until the screw rotation and back to achieve harmonization. Sometimes had the barrel temperature increased to the recommended set value or more in order to achieve this range.
　　Set too high back pressure can also lead screw stall or slip. Increase the back pressure setpoint will increase the energy into the material. If the back pressure is set too high, then the screw may not produce enough forward conveying melt pressure to overcome the back pressure of the back pressure, screw rotation will not be back in a position to do so will melt more functions and significantly improve the melt temperature, thereby adversely affecting the quality of products and cycles. Back pressure applied to the melt can be adjusted Dongguan Huahong brand through a control valve on the injection barrel.

　　Influence equipment
　　If the screw slippage is due to the processing device and not caused by process parameters, the screw and barrel wear is very likely to be a key issue. And feeding the same paragraph, when the resin melt in the screw compression segment adhered to the cylinder wall. When the screw rotates, the material is subjected to shear force after leaving the barrel wall to the front of the conveyor. If worn area on the screw and barrel, so the screw can not be effectively conveyed forward materials. If you suspect the device there is wear and tear, you should check the screw and barrel, and verify with the gap between the two. If the gap with the screw and barrel more than the standard value, replace or repair work should proceed.
　　Screw design parameters in particular the compression ratio (the feed zone depth than the homogenization zone depth) of plastics uniformity play a crucial role. Feed zone too light (get smaller compression ratio) would reduce productivity and due to lack of feed and cause screw slippage. Various resin suppliers generally recommend the best compression ratio injection materials.
　　Check ring (check valve) failure also cause screw slippage.
　　When the screw shaft and plastics materials, check ring should be in front of the (open) position, contact fixing ring seat. If the check ring is in the back (closed) state, or between forward and backward between the state, the molten polymer through a non-return