Insufficient filling

The material does not fill the cavity. When filling is insufficient, the product shows obvious material missing at the end of the cavity or at the thinnest wall, and the edge of the shortage is smooth or irregularly shaped. Similar to the short shot of '2079851475616104452, but in compression molding and transfer molding, insufficient filling may also be directly related to the feeding position and feeding method——if the material is unevenly distributed in the mold, local material shortage will occur even if the total amount is sufficient. Products with insufficient filling cannot be used, and their local unfilled areas of the mold will cause the flow pattern of the next molding to change.

1. Process parameter factors: insufficient transfer pressure, poor material flowability, gate blockage, low mold temperature, insufficient feeding amount.

1. Process parameter optimization and adjustment: increase the transfer pressure, improve material flowability (preheat), clean the gate, raise the mold temperature, increase the feeding amount. 2. Systematic troubleshooting method: Troubleshooting of transfer molding problems follows the order of 'runner -> feeding -> parameters -> mold'. First check whether the runners and gates are blocked or worn, then verify the feeding amount and material preheating, then adjust the transfer pressure and speed, and finally check the mold venting and temperature uniformity. 3. Preventive management: Establish standardized process parameter cards and quality control limits for each set of mold/product, and regularly conduct process capability index (CPK) evaluations. For recurring problems, use fishbone diagrams or 5Why analysis to trace the root cause, and solidify the countermeasures as PFMEA control points.

This problem is a typical manifestation of insufficient filling in transfer molding; the core of the solution lies in the rational design of the runner and gate system, the effective transmission of transfer pressure, and the uniform control of mold temperature. It is recommended to start troubleshooting from the runner system and transfer parameters.