Insufficient filling means that the end of the stream is incomplete or part of the cavity is not filled.
(1) The material has poor fluidity, the flow cannot fill the entire cavity, and the TPR/TPE injection molding defect solution: plastics with better fluidity should be selected.
(2) Poor exhaust of the mold can prevent the gas generated by the degradation of air or plastic from being discharged, resulting in excessive pressure at the end of the cavity, and the flow cannot fill the cavity. TPR/TPE injection molding defects. Solution: The countermeasure is to fill the mold at the end. Open the exhaust duct.
(3) The design of the mold casting system is unreasonable. For example, the position of the gate is unreasonable, the size of the gate and the size of the runner are too small, so that the melt flow is not smooth, and the flow cannot fill the cavity. TPR/TPE Injection Molding Problem Solution: The countermeasures are to improve the mold flow path and gate design, and to expand the gate and runner size.
(4) The material cooled by the stream front blocks the gate, runner and injection port, resulting in insufficient filling of the product. TPR/TPE injection molding defect solution: At this time, the size of the cold well should be enlarged.
(5) The nozzle and the die R value are inconsistent, so that the effective amount of the melt and the effective pressure are reduced, resulting in insufficient filling. Solution to the TPR/TPE injection molding defect: the nozzle should be consistent with the R value of the die.
(6) If the feed amount is too large, the effective pressure of the melt will decrease, and the flow cannot fill the cavity. TPR/TPE injection molding defect solution: reduce the feed, and the feed throttling method can be used to control the super feed of the smooth granular material.
(7) In the molding process, the values of the process parameters such as melt temperature, mold temperature, injection holding pressure and injection speed are too low, which will cause the filling length to be shortened, and the solution for cavity filling is insufficient TPR/TPE injection molding defects: Appropriately increase the value of these parameters.
(8) The nozzle temperature is too low, so that the temperature of the melt is reduced when it is injected into the cavity, which causes the filling length to shorten. TPR/TPE injection molding defects. Solution: When opening the mold, the nozzle should be separated from the mold to reduce the mold temperature to the nozzle. The effect is to keep the nozzle temperature within the specified range of the process.
(9) The injection stroke is too short to meet the requirements of the injection quantity of the product, resulting in insufficient supply of TPR/TPE injection molding defects. Solution: At this time, the injection stroke should be adjusted, and the feed port of the particle bridge or the counterflow of the nozzle should be checked. valve.
(10) In the multi-cavity mode, the casting system is unbalanced, so that the cavity away from the main runner cannot fill the TPR/TPE injection molding defect. Solution: You can adjust the width of the gate or make the length of each part consistent. The gating system is balanced so that the stream simultaneously fills the cavity
(11) In the multi-cavity mold, the injection speed of each level is set improperly, resulting in insufficient filling of the product. TPR/TPE injection molding defect solution: The first-stage injection speed should be increased, that is, high-speed injection is set, and when the material passes through the gate, it is reduced. Injection speed, plus time
(12) The design of the product is unreasonable, the length of the product is not proportional to the wall thickness, and the melt is easily blocked at the entrance of the thin-walled part of the plastic part, so that the product is insufficiently filled. TPR/TPE injection defect problem solution: This ratio should be adjusted to a suitable value. Generally, the wall thickness of the plastic part exceeding 8mm or less than 0.5mm is unfavorable for molding, and such wall thickness should be avoided.