You are here

When haute couture fashion meets biomimetic design

News International-French

30 Aug 2019

Complex components in medium to high volume require lean manufacturing technologies that allow for efficient material usage as well as precise and reproducible production. Thanks to its experience in haute couture embroidery, BIONTEC efficiently produces CFRP components in high volume.

Stitched textile, preform as well as moulded part – bicycle brake lever offering 50 % weight saving over aluminium

Tackling high cost of composites
Fibre reinforced composites offer many properties that allow a technically better solution compared to metallic materials: These cover, among other things, the high specific mechanical properties, which predestine the material for lightweight construction, but also low thermal expansion, a high degree of vibration damping and the integral design possibilities. However, major challenges lie in the design of the anisotropic material as well as in the often high costs. With the prevailing manufacturing techniques for carbon fibre reinforced plastics (CFRP), an economic use of the material, especially in medium to large quantities, is hardly conceivable.

Preform and finished bicycle crank showing integral design possibilities out of mould

BIONTEC’s novel approach: textile technology and biomimetic design
Thanks to 150 years’ experience in textile technology combined with comprehensive know-how in fibre reinforced plastics the company has developed its own manufacturing process from fibre to finished component for large serial production. BIONTEC adapted Tailored Fibre Placement (TFP) for high volume production and thus allows an efficient and robust preform manufacturing.

Serial production of net-shaped textiles on industrial embroidery machine

By sewing the reinforcing fibre onto a carrier material the optimum material combination for each specific challenge can be chosen. According to biomimetic design BIONTEC aims to achieve the best performance with minimum material usage by placing fibres aligned to the load path within the net shape of the component. By combining different layers of fibre into one stitched layup preforming can be simplified significantly. For more complex parts, several layups are combined like a puzzle into a three-dimensional stable preform. A high degree of automation reduces costs and typical defects such as gaps, fibre misalignment, wrinkles and so forth. The component is moulded net shape using Resin Transfer Moulding (RTM) minimizing machining efforts. Due to infusion optimized preforms and multi-cavity tooling, short cycle times can be achieved without the use of high pressure RTM systems, thus being the less prone to process-induced defects.

Composite manufacturing process optimized for serial production via Tailored Fibre Placement (TFP) and Resin Transfer Moulding (RTM)

Engineered to perform: from idea to serial production
BIONTEC develops components from first idea until serial production. Every single step in development is taken on the premise of enabling efficient production – whether the customer requires 100 or 100,000 parts per year. By using the vast knowledge in textile technology as well as composite production a product designed for manufacturing is obtained.

Wide range of products
The BIONTEC technology is particularly suited for complex parts that are rather limited in size. Parts can be manufactured monolithic, with sandwich cores or even hollow, depending on the specific requirements. Typically, high tenacity or high modulus carbon fibres are employed but other technical fibres such as glass, basalt or aramid fibres are used for special applications for example in medical technology.

Clamp: net-shaped textile and finished product saving 50 % weight over aluminium

A few fields of applications stand out
In metrology, especially when it comes to optical handheld devices, weight, stiffness and thermal expansion are drivers for applying carbon fibre composites. With the freedom of fibre steering combined with the automated manufacturing process, superior mechanical performance together with minimal variation can be achieved. Typically these products employ high modulus fibre and special resin systems reducing process-induced deformation such as spring in. Furthermore, the automation and short cycle time of the process allow significantly higher productivity than commonly applied prepreg hand-layup, thus cutting costs by half.

High strength and high stiffness shaft axle for paper machines

At the other end of the volume range the typical products being replaced are forged or die-cast aluminium. Using automation, multi-cavity tooling and fast-curing resins, production rates of 100,000 ppa can be achieved. Key enablers for such high volumes are net shaped preforming and moulding in order to reduce material waste and machining efforts to a minimum. Using ideal fibre orientations in a component can increase potential weight savings up to 50 % over aluminium, as several serial production parts from the bicycle industry show.

Other applications are the replacement of milled aluminium or titanium fittings for the aerospace and space industry where performance and part consistency can be well met. Such a structure for a scientific space mission in which, besides mechanical performance, thermal expansion, thermal stability and outgassing are the critical qualification criteria, is currently in development. For these purposes a new cyanate ester resin for injection has been utilized.

Serial production of brake levers: several parts can be produced in one shot allowing for 100,000 parts per year