Slush molding is a unique processing operation that was developed originally for polyvinyl chloride (PVC) based materials. It has been utilized to produce a variety of automotive interior products, including instrument panel skins, where relatively intricate designs are required. PVC becomes brittle upon aging, while thermoplastic polyolefin (TPO) doesn’t lose its ductility upon aging. TPOs have made significant inroads into interior applications in the form of thermoformed extruded sheet. However, when multiple grains, geometric (technical) grains, deep profile lettering, and logos are needed, slush molding is the preferred process. Currently, there is an increased demand for non-PVC slush moldable materials, such as TPO, that can meet these demanding aggressive styling requirements.
The semi-crystalline nature of TPO compositions renders them more difficult to process than PVC in slush molding. Moreover, TPO is typically a blend of polymers and has some unique challenges in slush molding. This paper will address the issues and challenges associated with formulating TPO materials suitable for slush molding.
Additionally, we will also discuss equipment and associated manufacturing requirements for these materials.