Tokyo, Japan – Polyplastics Co., Ltd. has developed a testing method that identifies gas formation during the injection molding process and helps to reduce mold deposits. The company’s Gas Investigation Method in Injection Molding (GIMIM) facilitates continuous molding and improves production efficiency.
During the injection molding process, harsh conditions (high temperature, high speed) and deterioration of plastic additives can release high volumes of decomposition gases. Mold deposits, gas burns, and short shots caused by pyrolysis gas can lead to quality problems, including undesirable effects on the dimensions and appearance of products, resulting in a higher defect rate. Maintaining highly efficient production operations is important as manufacturers work to meet today’s highly challenging applications such as automotive electrification and automation.
Polyplastics’ proprietary method captures and evaluates the gases formed during molding and identifies the mechanism by which pyrolysis gas forms during injection molding. The innovative proprietary method traps gases according to mold-based methods, uses gas chromatography mass spectrometers (GC/MS) to qualitatively and quantitatively analyze their composition, identifies the gases that are formed, and makes fundamental improvements to the sources of their formation.
This simple system configuration is divided into the three stages of plasticization, metering, and injection, and each unit is fitted with gas traps to seclude the gases that form within each part of the process. GIMIM can reflect the actual circumstances during molding by directly trapping and analyzing the gases formed during molding.
GIMIM makes it possible to measure high-molecular-weight substances that can cause mold deposits. Since this method directly analyzes gases that are formed inside the mold during filling, the company believes it yields results that are closest to real-world conditions. In further research, Polyplastics plans to examine other problems caused by pyrolysis gas such as short shots and gas burn defects, as well as mold deposits.