Body Shop Excellence - The Low Bake Way

A natural focal point in all this is the body and paint shops, which consume the highest amount of energy and have the highest CO2 emissions. Here, the use of low-bake adhesives has emerged as a game-changer. These innovative adhesives are engineered to cure at lower temperatures, reducing the energy required for the bonding process.

Sika identified the low-bake trend more than a decade ago. Its chemists and R&D experts carried out research into low-bake, heat-reactive materials that would allow curing temperatures as low as 135-140°C, compared to the typical 160-200°C required for conventional adhesives. Now the “dream goal” is 120°C, although anything lower (such as “cold bake” processes) will require a complete re-thinking of materials, Sika engineers say.

First, low-bake adhesives help carmakers reduce energy consumption and contribute to their sustainability goals. Since the body and paint shop consume high amounts of energy in the total automotive production, even a small percent reduction of electricity or heat can be significant, as one Sika engineer points out.

Secondly, the wider curing window ensures excellent bonding strength in hard-to-reach areas, where the standard targeted temperature is not fully achieved, such as reinforced parts around the battery in EVs or hidden side pockets. As one customer put it: “Insufficient heat dispersion is a challengeand adds more time due to warming up. Low-bake adhesives can potentially save us 10-15 minutes per cycle.”

To create its low-bake range, Sika teamed up with leading OEMs and component suppliers who were interested in working more sustainably. Together, they identified key requirements and challenges for each automotive body shop. No two lines were the same. However, despite the lower curing temperatures, the products needed to excel in bonding strength, sound blocking and controlled damping, reinforcement, and other key properties for automotive manufacturing. This required a no-compromises approach, tailoring of formulas and a lot of pre-testing.

Although Sika low-bake technologies are important in many parts of the vehicle, the focus is on four areas. These include all structural joints, where SikaPower® offers a well-proven range of high-strength adhesives; the rocker panels, where SikaReinforcer® serves as a heat-reactive and foamable epoxy material used for reinforcement; and in selected places,SikaDamp®; a family of sound deadening and vibration-reduction products. Finally, there is SikaBaffle®, which includes low-bake materials designed to improve vehicle acoustic performance by effectively sealing the car body and reducing noise transmission.

By taking a collaborative approach on sustainability and working as a strategic partner to automotive customers, Sika is developing solutions that reduce costs, simplify processes, and improve carbon reduction efforts. Clearly, sustainable vehicle design and manufacturing are becoming major factors in tomorrow’s car production.