Developed specifically for use with Santoprene and other thermoplastic elastomers (TPEs), a new family of water-based, heat-activated adhesives eliminates the need for costly surface treatments or primers. These new adhesives are designed to reduce the time and cost of manufacturing overmolded products used in appliance, medical, automotive, packaging, and construction applications.
Supplier Akron Coating and Adhesives (Akron, OH) says that although TPEs offer a number of advantages over thermoset rubbers including processability on standard extruding and injecting molding equipment and flexibility, manufacturers who choose to incorporate the materials into their products face several engineering challenges. "Products made from TPEs are very difficult to bond. In order to insure good adhesion TPEs must either undergo special surface treatment or be coated with a primer. Finally, most of the commonly recommended adhesives contain volatile and toxic solvents," explains Akron Coating and Adhesives.
Its new ACA 30-101, 102, and 103 adhesives "often" eliminate the need for primers and surface treatments altogether, thus substantially reducing the cost of using TPEs. The family of adhesives is designed to cover the entire spectrum of TPE grades from soft to very hard. They provide excellent adhesion, with peel values of up to and exceeding 25 lbs. per linear inch (including substrate tear). Typically, the adhesive is coated to the metal substrate and is processed using standard injection molding or extrusion equipment. Because they are water based, the adhesives also simplify EPA and OSHA compliance.