The choice of Borealis' XMOD GB306SAF 35% glass fibre reinforced polypropylene (PP) makes VW the first automotive OEM to switch from glass reinforced polyamides (PA) to polyproplene for the manufacture of air intake manifolds.
“Plastic air intake manifolds are used in the majority of vehicles produced worldwide today because of the optimised air flow, design freedom and general reductions in weight and cost they offer over their metal counterparts,” comments Dennis Nicholls, project manager MAHLE UK. “However, rising under-the-hood temperatures, demands for improved function integration capability, noise reduction and ever-lighter components, plus the need to reduce our own and our customers’ overall system costs, means we have had to look beyond polyamides to meet these challenges.”
Borealis worked with MAHLE Filter Systems, providing material development and computer aided design and testing support, to ensure the glass reinforced PP compound met VW’s requirements. These requirements included lower system costs without significant change in tool and part design, better acoustic behaviour, and use of an environment-friendly material. Same-speed production with MAHLE's existing injection moulding processes and post-moulding techniques was also required.
XMOD GB306SAF glass fibre reinforced PP from Borealis offers long-term high heat and chemical resistance, vibration resistance combined with high fatigue and a broad operating temperature of between -40°C and +120°C. Existing manufacturing equipment and processes for air intake manifolds can be used. As a lighter weight, lower density material it also enables weight reductions of up to 15% for air intake manifolds, while offering sound damping that surpasses current acoustic behaviour for air intake manifolds.
The Borealis PP composite also contributes to lowering overall production costs for air intake manifold parts as a result of its lower price and its lightweight benefits of improved handling and reduced energy usage. Lower processing temperatures and the lack of pre-drying further reduce overall energy consumption and eliminate manufacturing steps.