Sika Automotive specialises in bonding, sealing, damping and reinforcing technologies for vehicles, providing strong and lightweight chassis components to OEMs. In a recent pilot project, the company developed a plastic part to be installed in the lower A-pillar and B-pillar (towards the front) of a premium vehicle. The component is a complex shape made from robust polyamide and SikaBaffle, an elastic material which is printed at the edges of the component and expands during an e-coating procedure during assembly, to give the component its sealing and attenuating properties.
During a standard development process, body structures can be modified anywhere between five to ten times, which means plastic components can require several redesigns and prototypes before going in to manufacturing. Each modification means a new injection mould is needed, which can often incur lengthy manufacturing times and slow down the product development cycle. In a bid to cut development time, Sika Automotive started looking at 3D printing as an alternative.
The company decided on a German RepRap x500, an industrial plastic extrusion-based 3D printer which, due to its open printing parameters, could be modified to process the SikaBaffle material, a heat-reactive thermoplastic used to improve vehicle acoustic performance by sealing the car body and prevent dust, moisture and water from getting into the passenger compartment. This specific material was deemed to soft for most extruders so the machine’s parameters were adjusted to enable Sika to extrude the material and ultimately produce parts much faster compared to injection moulding. Additionally, the company says it is now also able to deliver plastic parts for small series manufacturing.
Several other industrial users have adopted German RepRap’s technology including Airbus Helicopters, which has been using the technology to proof a design of a new step module following the installation of the German RepRap x400 back in 2016 to produce prototypes and runs around the clock.