The Importance of Thermosets in Light-Duty Vehicles

Permanent. Durable. Resistant.

This is what you'll get when you use thermoset bonding technology.

Thermosets are cured creating permanent connections or cross-links into a specific shape. The chemical reaction that occurs in the thermoset material gives it a few key advantages, such as high thermal stability, resistance to moisture and humidity, resistance to chemicals and increased strength and durability.

This technology is ideal for high-touch areas exposed to the elements, such as the door panels, headliners and package trays.

Going Green

The typical drawback of the thermoset process is the release of formaldehyde, which is highly toxic, during the cross-linking process.

But, BASF has an innovative alternative. A zero-emission thermoset technology, Acrodur® is a water-based, formaldehyde-free, cross-linking resin that creates one byproduct during curing - water. It is an extremely low to no volatile organic compound (VOC) solution.

In addition, it is perfectly suited for molded parts made from a variety of fibers including glass, polyethylene, polyamid, wood and hemp. Opposed to its thermoplastic  counterpart,  Acrodur covalently bonds to these fibers providing improved mechanical performance. This technology in combination with natural fibers creates state-of-the-art lightweight composites utilizing renewable non-woven fibers with reduced binder content, 25 to 30 percent of total weight as opposed to 50 percent.

Mechanical Performance Comparison

When compared to other natural fiber or wood fiber binders in its category, Acrodur produces similar behavior but with significant advantages in lightweighting and sustainability. These advantages are important in the automotive industry as OEMs are striving to reduce vehicle weight without sacrificing performance or eco-friendliness.

Data courtesy of Dräxlmaier Group:

Thermosets: BASF Acrodur Technology Performance Metrics

Leading by Example

The product hit the streets when BMW incorporated the door panel composite, as pictured below,  into its award-winning BMW 7 Series luxury sedan. It is a cost-efficient solution that creates extremely stiff but also lightweight three-dimensional objects in one production step. In 2009, Acrodur took home the Society of Plastic Engineers Innovation Award.

Due to their excellent shelf life, these composites can be produced as blanks and supplied to Tier 1 companies for on-site molding. In addition, they can be combined with pigments, flame retardants and other additives before the resin is impregnated into the non-woven material and cured.