Product dimensions out of tolerance

The product dimensions are unstable. When this defect appears in products of Process No. 4, it is usually related to a specific process parameter range or equipment state. If it continues to appear, it will directly affect the product qualification rate and production rhythm, increasing material loss and rework costs. Timely diagnosis and elimination is a basic requirement for ensuring stable production.

1. Process parameter factors: curing condition fluctuation, feeding amount fluctuation, transfer pressure fluctuation, mold temperature fluctuation. 2. Runner and gate design factor: In transfer molding, the material needs to enter the cavity through runners and gates; the runner length, cross-sectional shape and gate size directly affect pressure loss, fiber breakage and filling balance, and unreasonable design is the root of many quality problems.

1. Process parameter optimization and adjustment: stabilize the curing process parameters, precisely control the feeding amount, stabilize the transfer pressure, control the mold temperature. 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 product dimensions out of tolerance 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.