Lightweight, high-strength continuous carbon fiber thermoplastic composite shell, ten times stronger than injection molded parts

Lightweight, high-strength continuous carbon fiber thermoplastic composite shell, 

ten times stronger than injection molded parts

Bristol-based Tri-Mack Plastics Manufacturing, a manufacturer of high-performance thermoplastic parts, recently announced its latest product development, a lightweight, high-strength enclosure made from just eight layers of unidirectional (UD) carbon fiber-reinforced thermoplastic (CFRTP) tape and only 0.40 inches thick.

The new housing demonstrates Tri Mack's expertise in producing large, thin closures with deep draws using UD tapes. At the CAMX conference, the company demonstrated a range of protective surface sizes and materials made using Tri-Mack's production processes, including automatic tape lay-up ATL, press molding and more. The company claims that Tri-Mack's thermoplastic composite process produces parts in just minutes, unlike thermoset plastics, which take an extremely long time.

For more than a decade, Tri-Mack has been developing proprietary methods for automated lay-up and molding of lightweight thermoplastic composites," said Tom Kneath, vice president of sales and marketing for Tri-Mack Plastics Manufacturing. "We believe these new TPC (thermoplastic composite) shields meet the growing demand for strong, lightweight composite parts. The growing demand for strong, lightweight enclosures where strength and durability are priorities in addition to the lightest weight, and continuous fiber TPC is the material of choice. It is less brittle than thermoset, 10 times stronger than injection-molded parts, and reduces enclosure weight by 30% compared to 6061 aluminum."

The new housings are not limited to carbon fiber; they can be produced using glass fibers, as well as different matrix resins, including polyaryl ether ketone (PAEK), polyether ether ketone (PEEK) and polyetherimide (PEI), and offer a variety of customizable properties and solutions.

Tri-Mack noted that the manufacturing process for enclosures also allows for additional functionality, creating "smart composites" by embedding EMI shielding or adding localized reinforcement through custom lamination. Max McCabe, sales engineer, added, "We can add conductive layers to the process to achieve EMI shielding performance at a fraction of the weight of metal; this also eliminates the plating and painting process steps typical of EMI solutions used on composite parts." McCabe noted that the conductivity and shielding effects can be tailored to the end use, further broadening potential applications in aerospace, unmanned aerial vehicles (UAVs), underwater applications and electric vehicles (EVs), among others.

Ben Lamm, process engineering manager at Tri Mack, who led the new housing project, said there was a definite technical challenge in forming a large, deep housing from TPC. Using UD materials, layers can be stacked in different directions throughout the part," he said. Making complex shapes in this way requires the layers to slide over each other during the molding process. Getting them to move the way they want to produce consistent, wrinkle-free parts requires challenging lay-up and tooling designs, and very precise material handling during processing."

For this 48-year-old company, this level of manufacturing expertise is par for the course. "Tri-Mack has been working with lightweight composites for decades and has a full range of capabilities," Kneath said. "We manufacture injection-molded housings that require EMI shielding and thin-walled TPC enclosures that use assemblies and fasteners instead of metal. Our goal is to build this functionality into a single component and show the industry how lightweight construction can improve product performance through fuel efficiency, battery life history or increased payload."