An Asian automaker has replaced machined aluminium with a carbon fibre-reinforced composite in an injection moulded oil control valve within the variable valve timing system that controls engine intake and exhaust.
The high-performance thermoplastic valve (2-8 valves per vehicle depending on engine size) reduces cost and weight and improves engine response time.
The Sumiploy CS5530 resin is produced by Sumitomo Chemical, of Tokyo, Japan, and sold in North America by Sumitomo Chemical Advanced Technologies, which will exhibit at the Society of Plastics Engineers’ Automotive Composites Conference & Exhibition (SPE ACCE), 5-7 September, in Novi, Michigan, US.
Sumiploy is a formulation of Sumitomo’s SumikaExcel polyethersulfone (PES) resin plus chopped carbon fibre and a proprietary additive package that boosts wear resistance and dimensional stability. The resulting composite is said to offer excellent thermal resistance, good dimensional stability and long-term creep resistance over a broad temperature range, good impact strength, chemical resistance to aromatic hydrocarbons like gasoline, ethanol, and engine oil, inherent flame retardance, and high environmental stress-crack resistance (ESCR). Unlike many other high-temperature thermoplastics that are challenging to mould, Sumiploy CS5530 is high-flow, making it easier to mould high-precision 3D geometries in thin walls.
For the oil control valve, key engineering requirements that Sumiploy CS5530 composite had to pass include ultra-high dimensional accuracy (10.7 mm ± 50 mm or 0.5%), thermal stability from -40 to 150oC, low coefficient of friction, chemical resistance to engine oils, and excellent fatigue strength and creep resistance. Drivers for making the change from machined aluminium to a thermoplastic composite include lowering manufacturing costs, improving engine performance, and lowering weight. The part has been in commercial use since 2015. Being a thermoplastic, it is fully recyclable (melt reprocessable) at the end of vehicle life.
Sumiploy resins are also well suited for use in electrical/electronics and aerospace components to replace machined steel or aluminium as well as other high-performance thermoplastics like polyetheretherketone (PEEK), polyaryletherketone (PAEK) and polyetherimide (PEI). While not critical for this application, Sumiploy resins offer reduced friction against mating surfaces in minimally lubricated environments as well as enhanced functionality and lower manufacturing costs thanks to the parts consolidation from high-precision injection moulding. The resins are good candidates for metal replacement in applications like oil control valve pistons, solenoid valve pistons, heating/ventilation/air conditioning (HVAC) vanes and pistons, industrial gears, and non-lubricated bushings and bearings.
For the first time, Sumitomo Chemical Advanced Technologies will exhibit at SPE ACCE. In booth 221, the company will display information on Sumiploy polymer alloys as well as SumikaExcel PES, SumikaExcel micro-powder additive, and SumikaSuper liquid crystal polymer (LCP).
Image provided by Sumitomo Chemical
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