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Gas injection molding of reinforced engineering plastics for structural applications is a very innovative approach, but is still in an infancy stage. The requirements for window guidance channel are: dimensional stability, high strength to weight ratio, no warpage and low wear. The composite materials with hollow tubular structure can only meet these requirements based on FEA analysis. We evaluated 30% glass filled polyester (short and long glass fibers). The part and tool designs are the key parameters for successful results which are discussed. Information on current gas injection molding technologies is discussed. The new software ‘C-Gas flow analysis’ was used to optimize gate design and process parameters. The design of experiments based on Taguchi method was used. Both available technologies, i.e., gas through nozzle and gas through runner or cavity were tested. The cross section analysis was done using CAT Scan.

TPO is getting wider acceptance for automotive applications. An exterior application like a fascia is a very good example. Interiors are still a challenge due to many reasons including overall system cost. For interior applications, “all-olefin” means it mainly consists of three materials: TPO skin, cross-linked olefinic-based foam and PP substrate. The driving force for TPO in Europe is mainly recyclability while in the USA, it is long-term durability. This paper describes the key limitations of the current TPO systems which are: poor grain retention of TPO skin, shrinkage in-consistency of the skin, high cost of priming (or other treatments) and painting of the skin, lower process window of the semi-crystalline TPO material during thermoforming or In-mold lamination / Low pressure molding, high cost of the foam, low tear strength of the foam for deep draw ratio etc.