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Structural Reaction Injection Molding (SRIM) is generally regarded as a thoroughly developed technology and is currently utilized in many automotive applications; most prominently door panels but also other applications, for example package trays and headliners. The traditional production process involves the placement of a glass fiber mat into a mold prior to injection of a suitable liquid resin system. Upon removal of the part, the glass mat is thoroughly encapsulated by the resin system forming a structural composite material. In the new Long Fiber Injection (LFI) process, the glass fibers are injected along with the resin mixture onto the production mold. This new process demonstrates a new approach to high productivity, low cost manufacture of LD-SRIM composites.

LD-SRIM process technology, which can be readily tailored to match material physical property requirements to end-use applications, is answering the interior trim automotive engineers call for high quality, durable and cost-effective low weight composites. Due to their versatility, LD-SRIM composites, produced by reinforcing a water-blown MDI polyurethane foam matrix with a non-woven fiberglass mat, are successfully displacing PP and ABS thermoplastics, as well as wood fiber composites, in a wide variety of interior trim substrates. The technology's benefits, such as the ability to produce low weight parts (down to 0.27 g/cc for door panels) via pour-in-place techniques, and recent developments in internal mold release (IMR) formulations, have resulted in dramatic growth as demonstrated by its use in an expanding number of North-American produced vehicles.

ICI Polyurethanes has developed a series of structural reaction injection molding resins for automotive interior trim applications. These new resin systems are CFC-free polyurethane foams specifically designed for glass mat reinforcement. These light weight composites can be described as low density structural RIM, LD-SRIM. LD-SRIM can offer a weight reduction of 50% over competitive materials with similar physical properties in applications such as door panels. A LD-SRIM composite with 20% glass reinforcement and a specific gravity of 0.55 g/cm3 has a flexural modulus of 2370 MPa. The LD-SRIM process has several benefits such as the consolidation of manufacturing steps achieved through molding in fasteners or decorative materials and the design flexibility inherent to liquid molding technology.

Management of manufacturing scrap and post-consumer scrap from automobiles will increasingly influence both the acceptance of plastics and choice of plastics in the automotive industry. Polyurea elastomers made by reaction injection molding (RIM) offer many processing, property and cost advantages desired by the automotive industry but their crosslinked nature has generally implied that the scrap cannot be recycled by a widely used recycling method, thermal processing. Recently introduced ICI Polyurethanes imine-polyurea materials for automotive exterior applications can be thermally processed using extruders into sheets, profiles, tubes, moldings etc. The extruded materials have good mechanical integrity and many end-use applications are possible.

A new polyurea RIM elastomer suitable for molding large parts and offering significant improvements in high temperature properties, impact strength and dimensional stability relative to current automotive grade RIM elastomers has been developed by ICI Polyurethanes (Rubicon Chemicals Inc.). The evolution of RIM materials leading to the development of this innovative product is described herein. Related advances in the in-situ treatment of flaked glass reinforcements leading to improvements in demold toughness, heat sag, and coefficient of linear thermal expansion are also detailed. Physical properties illustrating the benefits of this new polyurea RIM system are compared to amorphous nylon and a polyphenylene oxide/nylon alloy.