Faster, thinner, lighter, robust, sustainable – the set of requirements which modern mobile devices must meet is becoming increasingly stringent with each new generation of products launched on the market. The challenge has been to come up with the materials that can fulfill these demands in sufficient volumes while remaining cost-efficient. Recognizing this need, Covestro has developed a completely new composite technology based on thermoplastics and carbon fibers, that, says the company, can meet these requirements in full.
The technology, called Covestro CFRTP (continuous fiber-reinforced thermoplastic) composites, are based on films of endless unidirectional carbon fibers (UD films). Several layers of these films are positioned one on top of the other, cut and then laminated. This produces extremely stiff and lightweight composite sheets with no distortion or shrinkage. The number, direction and sequence of layers can be optimized for the relevant application, such as housings and other components. Unlike thermosetting plastics, the composites can be easily recycled at the end of their service life.
According to Covestro, these CFRTP (continuous fiber-reinforced thermoplastic composites) solutions come into their own when used in consumer electronics products. Unlike typical semi-finished plastic materials, they feature an ‘organic’ pattern, are cool to the touch thanks to their excellent thermal conductivity, and sound like metal on impact.
“They provide the best strength-to-weight ratio of all standard composites on the market and also outperform metals in this respect, which means they’re ideal for making parts for IT devices that are impressively robust despite their thin-walled, lightweight design,” said David Hartmann, who is heading the area of thermoplastic composites at Covestro, together with Dr. Michael Schmidt. They also fulfill the high standard of Underwriters Laboratories’ UL94 V-0 flammability rating.
Unlike small-series production with thermosetting plastics, Covestro CFRTP solutions enable flexible, cost-efficient mass production. Two of the reasons for this are short cycle times – with minimal manual work – and high yields. The sheets are easy to transport without any cooling or special treatment, and are ready for further processing by the customer.
An additional advantage is the unprecedented level of design freedom which the use of these materials provides to product designers. Different combinations of resin and fibers can be used to create specific visual effects and textures – in the mold or using sandblasting, CNC milling or laser cutting, for example. Coating and various printing or embossing processes offer possibilities for adding further design features; openings and functions can also be integrated into the components themselves.
Covestro has committed to furthering this technology, as evidenced by the investment in research in this area, last year’s acquisition of a company specializing in composites, and the company’s current efforts to establish a global production network and an expanded product portfolio. “We’re also working with machine manufacturers and carbon fiber suppliers to press ahead with the rollout of this technology,” said Dr. Michael Schmidt.
Next to the electronics market, the company is exploring other application areas, as well, such as the automotive and transport industry. Lightweight and strong, Covestro CFRTP composites could offer new design options for components used in the automotive and transport industry, such as door trim, bodywork parts and backrests for automobiles. In buses, trucks and railroad cars, the composites could be used for applications such as interior and exterior paneling.
Covestro will be showcasing its CFRTP solutions at K 2016, Hall 6, Stand A 75.