Prepreg tack loss

The prepreg cannot be bonded during use. When this defect occurs in products of Process No. 3, it is usually related to a specific process parameter range or equipment status. If it persists, it will directly affect the product qualification rate and production cycle, increasing material loss and rework costs. Timely diagnosis and elimination is a basic requirement to ensure stable production.

1. Material factor: Excessive B-staging of the resin due to too long storage time, high storage temperature causing pre-curing, release agent adsorbed on the surface, and insufficient tackifier in the resin formulation. 2. Preheating factor: The preheating temperature and time of the material (especially thermosetting molding compounds) directly affect its flowability and curing behavior; improper preheating can lead to poor filling or uneven curing, which is a key control point unique to compression molding. 3. Molding pressure factor: In compression molding, pressure is not only used to overcome flow resistance, but also directly affects the compactness of the product and the degree of fiber wetting; insufficient pressure is an important cause of loose products and insufficient strength.

1. Process parameter optimization and adjustment: Control the storage conditions and time, store at low temperature, check the tack before use, and adjust the tackifier amount. 2. Systematic troubleshooting method: Compression molding problem troubleshooting follows the order of "material -> temperature -> pressure -> mold". First check the preheating and flowability of the material, then verify the mold temperature distribution and curing time, next adjust the molding pressure and mold closing speed, and finally check the mold venting and demolding conditions. 3. Preventive management: Establish standardized process parameter cards and quality control limits for each mold/product, and regularly conduct process capability index (CPK) assessments. For recurring problems, use fishbone diagrams or 5Why analysis to trace the root cause, and solidify countermeasures as PFMEA control points.

This problem is a typical manifestation of prepreg tack loss in compression molding, and the core of the solution lies in the reasonable preheating of the material and the guarantee of flowability, as well as the precise matching of mold temperature and molding pressure. It is recommended to make coordinated adjustments from both the material state and process parameters.