PlastiComp Inc. (Winona, Minn., USA), a manufacturer of long-fiber thermoplastic (LFT) materials and technologies, has expanded its Complēt LFT composite pellet product line to include drop-in replacements for die-cast magnesium. The new LFT products duplicate the mechanical and electrical properties of magnesium with injection molding or extrusion materials that offer up to 40 percent reduction in weight.
PlastiComp’s new LFT composites match the mechanical performance of pressure die-cast magnesium and aluminum with tensile modulus values up to 42,000 MPa. On the electrical side, they offer surface resistivity values down to 0.2 ohm/sq and EMI shielding capabilities in the 60-80 dB range depending on wall section thickness.
PlastiComp says the combination of mechanical and electrical properties provided in these new LFT composites are achievable in a range of polymers from commodity to engineering resins based on performance requirements and price sensitivity. In addition to hand-held devices and peripherals in the consumer electronics industry, PlastiComp’s new magnesium substitution LFT composites can also replace metal-profile extruded frames within the automotive industry.
“Structurally, long-fiber reinforced composites have a history of successfully being used to replace metals, such as aluminum, because they offer weight savings and easier fabrication, which provide considerable cost reductions. Where composites have previously fallen short is in meeting the combination of both structural and electrical characteristics of metals,” said Raj Mathur, Ph.D., vice president technology at PlastiComp. “It is common in the consumer electronics and automotive industries to use metals like magnesium for their stiffness and EMI shielding properties. Now, PlastiComp is able to offer LFT drop-in substitutes that allow these types of metal applications to be converted to long fiber.”
“Even though our new materials contain both long-fiber reinforcement and nano fillers to achieve magnesium substitution properties, they mold extremely well,” says Mathur. “PlastiComp has already successfully demonstrated commercial applications, with cross sections in the 0.7- to 1-mm range, which were injection molded without any difficulty using these LFT composites. Microstructural characterization showed a conductive network of intertwined carbon fibers and uniform dispersion of the nano fillers throughout the parts.”