Technical Paper
Production of Modular Window Gaskets Using Light Stable Polyurethanes
1990-02-01
900516
The advantages of modular windows with the gasket molded directly onto the glass are now well established. These windows offer aerodynamic design, variable gasket cross-section, molded-in attachments and ease of installation. This greatly increases styling and design flexibility compared to windows with conventional gaskets. There are several choices of molded gasket material which include: PVC, post-painted polyurethane, in-mold coated Polyurethane and light stable polyurethane. Polyurethane processed by reaction injection molding (RIM) is typically selected for larger windows. Polyurethanes can be formulated to give a wide range of flexural modulus values and are readily molded into the long narrow cross-sections characteristic of window gaskets. The use of PVC is limited by the high temperatures, high injection pressures and high clamping forces needed for injection molding of thermoplastic materials.