The injection molding journey can be quite challenging as manufacturers try to navigate the perils of shear-induced heating and fill imbalances. Some companies are more well-prepared for this journey than others, and Quest Industries is at the forefront of knowing what resources they have at their disposal to achieve well-made plastic parts.
The Lapeer, Michigan company known for designing and manufacturing high-quality plastic injection molds (in addition to rubber molds and microcellular polyurethane tooling) was faced with a significant gas trap issue that developed in a new, transparent cover application. The application required a flawless cosmetic finish along with the ability to form a hermetic seal.
During development, the single cavity mold appeared to pass all tests and the expectation was that the first shots would deliver ideal parts for their customer.
When the unexpected gas trap issue arose during molding (see image at right), Vice President of Manufacturing Matt Trisch immediately recognized the shear-induced melt variation occurring during fill and contacted Beaumont. He had successfully used MeltFlipper in the past and saw that their mold could also be an ideal application for the technology.
Beaumont’s simulation team ran a Moldflow analysis on the project and was quickly able replicate the production issue. You can see here on the left how the gas trap was forming at the end of fill.
After designing a custom MeltFlipper runner system for this application, Matt and his team at Quest retrofitted their existing mold. The first samples off the press showed that the problem was resolved, leading to a very happy customer.
The MeltFlipper was able move the gas trap to the parting line where it could be properly vented out.
Here you can see before and after simulation outputs showing the distribution of the hotter, higher-sheared plastic in the part. On the left (before) it wrapped quickly around the sides of the part creating the gas trap. The after image (right) shows how MeltFlipper is distributing the higher-sheared plastic evenly to both sides of the part, controlling the plastic flow for a more favorable fill pattern.
The before and after part images here show the final result.