MATERIALS: Injection-Moldable Thermoplastic Composites Boast To Be Strongest Yet

Piper Plastics' new thermoplastic composites are said to bridge the gap between standard reinforced thermoplastic compounds and pre-preg lay-up composites.

A new line of injection-moldable thermoplastic composites developed by high-performance machining company, injection molder and plastic component design firm Piper Plastics, Chandler, Ariz., reportedly bridge the performance gap between standard injection molding compounds and pre-preg lay-up composites. Kyron MAX materials allow parts to be injection molded at high volumes with strengths that approach lay-up composites and metals. Targeted markets include aerospace, automotive, industrial, oil & gas, and medical.

            The new line includes three series with progressively higher tensile properties because of the fillers used, respectively, as follows: Series S includes PEEK, PPS, PEI, PPA, and nylon 6/6 reinforced with the company’s proprietary MAX fibers and sizing technology and targeted to replace aluminum, cast iron and magnesium; Series ES and Series XS are comprised of PEEK and PPA reinforced with MAX fibers, glass fibers and carbon fibers.  Series ES is targeted to replace steel, aluminum, cast iron and magnesium whereas XS can replace titanium, stainless steel, steel, aluminum, cast iron and magnesium.  According to materials engineering manager Dave Wilkinson, Series S materials are designed for conventional injection molding whereas ES and XS are designed for proprietary high-pressure molding technology developed by the company.

            Among the key features of the Kyron MAX materials are higher than steel tensile strength at over 100,000 psi, weight that is nearly 75% less than steel and about 60% less than titanium, and the ability to mold components in a high-volume, tightly controlled process that significantly reduce the manufacturing costs associated with pre-preg lay-up composites. Wilkinson also emphasizes the better “practical toughness” due to lower filler loadings than used in traditional thermoplastic compounds due to the MAX fiber and sizing technology. It generates high mechanical performance—better knit strength and less directional strength as well as higher ductility.  A broader processing window and reduced weight are also claimed.

Wilkinson notes that they are working to replace an automotive component previously made of nylon 66 reinforced with 60% long-glass fiber loading, with a nylon 66 reinforced with 20% MAX fiber, resulting in 25% lower weight and more ductility. Potential interior automotive applications include screws and nuts and bracketing as well as underhood components. 

Working with several aerospace companies and using a material from the XS Series, the company developed a ¼ in., single #10 plastic screw based on titanium screw geometry which can hold a load of over 700 lbs and is half the weight of the titanium screw. (480) 926-8100 •

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