In-Cavity Buildup

What it is:

Buildup of release agents, the material being molded, or byproducts and residues generated by chemical reactions that take place within the mold cavity (in situations where the compound is chemically being changed along the molding process) negatively affect molding performance in terms of heat transfer, part-dimensional properties, cosmetic appearance, and process efficiency.

Causes:

Buildup issues can be created by two primary sources:

• Excess of release agent present on the mold. This may be the result of a poor choice of release agent for the specific application (e.g., not compatible with the process temperature) or over-application of the release agent onto the mold.
• Lack of release barrier causing buildup of the material being molded or byproducts and residues generated during the molding process. In this case, the choice of release agent may not be adequate for the process conditions (not suitable for the process temperature, poor film formation, etc.). This may also be caused by application deficiencies (not enough release agent film present on the mold) or lack of physical and/or chemical resistance of the release agent to the material, which then penetrates the release agent film and physically or chemically adheres to the mold.

Solutions:

Problems such as these can lead to significant inefficiencies in your operation and cost you a lot of money in rework, scrap, and wasted resources. Chem-Trend has the knowledge and experience to provide your operation with solutions tailored to overcome these problems.

RELATED CASE STUDIES