Time to automate with prepreg tapes

Huntsman Advanced Materials has been supporting Swiss pre-impregnated materials specialist North Thin Ply Technology (NTPT) to produce ultra-thin prepreg components on a Richard Mille luxury watch case. Founded in 2009, NTPT designs and manufactures ultra-thin prepregs for high performance composites applications. From its main facility in Switzerland, the company's 25-strong team focuses on the research and development of prototypes and small series production. The business offers spread tow and associated pre-pregging techniques to manufacture uni-directional prepreg tapes processed with thermoset resins, which can be as thin as a third of a human hair in diameter. To facilitate their handling, the company has also developed an automated tape laying system. NTPT's technology package is completed with simulation software which enables efficient parts designs, taking advantage of the uniqueness of ThinPregs. Based on its track record and expertise in formulating specialty components for impregnation systems and its understanding of the specific requirements of ultra-thin prepreg processing, NTPT decided to work with Huntsman on the watch case project. The watch cases are made from thick blocks of 400 thin ply of ThinPreg carbon fibre uni-directional tape, pre-impregnated with an epoxy resin matrix system based on building blocks of resin, toughener and hardener, selected with Huntsman's support. Because of the ultra-thin interply thickness, the autoclave cured block can be considered as a one phase material which is machinable in the same way as metal. NTPT selected the Huntsman combination of building blocks for this particular application specifically for their ability to meet the necessary criteria required for manufacturing ultra-thin prepreg tapes, as well as their filament bearing properties and the resulting resistance to delamination and crack propagation, which provides the cured uni-directional tapes with outstanding machinability behaviour. Gilles Rocher, sales & marketing manager, NTPT, commented: "Both the reinforcement material and matrix system play an equally important role in achieving the right balance of desired properties. Matching process to performance was key to the success of this project. Thanks to the excellent product recommendations and ongoing technical support received from Huntsman, we have been able to achieve our goals in applying prepregs to deliver the highest level of quality within an extremely durable and lightweight watch case that is built to last." Today, prepreg composites have become the benchmark across many sectors of the composites industry, applied for their ease of use, consistent properties, high quality surface finish and the wide choice of types that are now available. More and more markets including the wind energy, automotive and general transport sectors are adopting prepreg composites to integrate greater efficiencies at every level during manufacturing whilst also focusing on fulfilling higher strength to weight requirements. Huntsman's wide offering of specialty building blocks and specially formulated resin matrix systems, and its involvement in industry-leading projects such as the Richard Mille watch case, shows how the company is bringing the value of discovery to success in commercial propositions and facilitating the continued growth of the market for prepreg composites.