One of the common defects in the injection molding process of TPE materials is that there is an incomplete end of the finger flow or a part of the multi-cavity in one mold is not filled. So do you know how to solve the dissatisfaction of TPE materials? Here's what you know:
Possible causes of glue dissatisfaction in TPE materials and solutions:
1. The fluidity of TPE material is not good, and the material flow cannot fill the entire cavity.
Solution: TPE material with good fluidity should be selected.
2. The gas generated when the air or plastic is degraded cannot be discharged due to poor exhaust of the mold, resulting in too high pressure at the end of the cavity and the material flow cannot fill the cavity.
Solution: When such a situation occurs in TPE materials, we can open an exhaust groove at the final filling of the melt.
3. The design of the mold gating system is unreasonable, such as: the gate position is unreasonable, the gate size and the runner size are too small, so that the melt flow is not smooth, and the material flow can not fill the cavity.
Solution: Improve the design of mold runner and gate, and expand the size of gate and runner.
4. The material cooled by the material flow front blocks the gate, runner and injection port, resulting in insufficient filling of TPE material products.
Solution: At this time, the size of the cold material well should be expanded.
5. The R value of the nozzle and the die is inconsistent, which reduces the effective amount and effective pressure of the melt, resulting in insufficient filling.
Solution: The nozzle should be consistent with the R value of the die.
6. If the amount of material is too much, the effective pressure of the melt will drop, and the material flow will not be able to fill the cavity.
Solution: To reduce the feeding, the feeding throttle bolt method can be used to control the overfeeding of slippery granules.
7. The temperature of the nozzle is too low, so that the temperature of the melt is reduced when it is injected into the mold cavity, resulting in the shortening of the mold filling length.
Solution: The nozzle should be separated from the mold when the mold is opened, so as to reduce the influence of the mold temperature on the nozzle and keep the nozzle temperature within the specified range of the process.
8. In the multi-cavity mold, the gating system is unbalanced, so that the cavity far away from the main sprue cannot be filled.
Solution: By adjusting the gate width and size or making the flow channel length of each part consistent, the gating system is balanced, so that the material flow fills the cavity at the same time.
9. In the multi-cavity mold, the injection speed at all levels is set improperly, resulting in insufficient filling of TPE material products.
Solution: The first-stage injection speed should be increased, that is, the high-speed injection should be set, and when the material passes through the gate, the injection speed should be reduced and the time should be increased.
10. The injection stroke is too short, which cannot meet the requirements of the product for the injection volume, resulting in insufficient feeding.
Solution: The injection stroke should be adjusted, and the supply port of the particle bridge should be checked or the nozzle counterflow valve should be adjusted.
To sum up, it is the analysis of the reasons for the dissatisfaction of TPE materials and the corresponding solutions. If you encounter the problem of dissatisfaction with the tape material, you can analyze the reasons and solve it according to the above.