From metal and plastic repair, to sanding, paint finishing and truck clean-up, 3M has the products and repair processes for heavy duty truck repair. One of the materials commonly used in heavy duty trucks is METTON® LMR (Liquid Molding Resin), a tough and durable engineering plastic material used to produce large or thick molded parts.
However, identifying and repairing METTON® as a substrate requires a different approach than fiberglass (FRP) and sheet molded compound (SMC). 3M Automotive Aftermarket Division now offers Standard Operating Procedures (SOPs) for repairing this material.
What is METTON® and Where Is It Used?
Light-weighting is a process that is a high priority for heavy duty truck manufacturers. Efforts to reduce vehicle weight are driven by Corporate Average Fuel Economy (CAFÉ) standards and competition among vehicle manufacturers. Innovative technologies and materials have contributed to the ultimate goal of delivering increased fuel efficiency to the heavy duty truck customer.
One area that has received significant attention has been the weight of exterior body panels. Body panels have gotten lighter due to design, material and manufacturing improvements over time. One material that has increased in use for exterior truck body panels is METTON® LMR. METTON® is produced using a closed mold process which helps deliver more consistent parts with tighter tolerances, improves manufacturing cycle times and enables increased design freedom compared to other materials and processes. This material is lighter than traditional fiberglass and SMC. Additionally, it’s more rigid and impact resistant, especially in colder climates, than many plastics such as thermal plastic olefin (TPO). Many exterior truck body panels today are being produced using METTON® including hoods, roof and chassis fairings, bumpers and fenders.
Identification of METTON®
METTON® is black in color and is more rigid when compared to other plastics like TPO. When grinding or sanding during the repair process, METTON® does not produce a cloud of airborne, itchy dust like FRP and SMC panels as it does not contain fiberglass fibers. METTON® will grind and sand more evenly compared to other plastic materials. For example, METTON® doesn’t smear and flow as much as TPO can during grinding and sanding operations. Another indication of working on METTON® is the very distinct, unique odor that is produced when grinding or sanding this material.
Now METTON® has been identified, how is this material repaired? 3M has developed a Standard Operating Procedure for a Backside Reinforcement Repair and a Cosmetic Repair for composite materials that includes FRP, SMC, and METTON®. Repair procedures for METTON® are surprisingly similar to the repair processes body technicians use for SMC and other plastics. The most critical difference between repairing METTON® and SMC is the use of an adhesion promoter such as 3M™ Polyolefin Adhesion Promoter. Adhesion promoter is necessary to increase the bond strength between the repair adhesive and the surface of the METTON®. This should be a standard practice when using adhesives on other plastics such as TPO and Polypropylene (PP) as well.
To date, 3M AAD offers 37 Heavy Duty Truck Standard Operating Procedures (SOPs) online at www.3MCollision.com/HDTruck. From metal, plastic and composite repair, paint finishing and truck clean-up, 3M has effective systems, products and repair processes. There are, of course, many factors and variables that can affect an individual repair, so the technician and repair facility need to evaluate each specific application and repair process, including relevant vehicle, part and OEM guidelines, and determine what is appropriate for that repair. When repairing heavy duty trucks or commercial vehicles, repair professionals can feel confident their repair is done professionally and efficiently using the 3M AAD Standard Operating Procedures. These procedures will help consistently produce quality, time-proven results for any of collision repair needs.
For more Standard Operating Procedures, visit www.3MCollision.com/HDTruck.
3M Automotive Aftermarket Division Keeps the World Moving
3M automotive products keep the world on the move, with innovative solutions for building, repairing and maintaining vehicles. From the collision repair professional to the individual vehicle enthusiast, people around the world trust 3M products to protect, repair and keep their vehicles looking showroom new. And our commitment to this industry extends beyond product performance to a careful stewardship of the world’s resources and environment. Serving the needs of our customers has made 3M a trusted leader in vehicle care and repair, and we are dedicated to earning that trust each and every day.
For more information, contact 1-877-MMM-CARS, contact your local 3M Distributor or 3M Sales Representative or visit the website at www.3Mcollision.com. Follow 3M AAD on Facebook at
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