Building a better bond

Recent developments in thermoplastic elastomer (TPE) formulations mean the high-demand soft materials are now able to bond with textiles, numerous metals and acetal parts. This new capability opens up many possibilities for parts integration and reduced system costs.

Ticona has worked with a German TPE supplier to engineer a TPE that will bond with acetal, overcoming acetal’s inherent lubricity. As well, Advanced Elastomer Systems has introduced new enhanced-bonding grades of Santoprene TPE that use heat and pressure to achieve a bond to a variety of substrates, including coated fabrics; aluminum; brass; copper; stainless steel; and etched fluoropolymers, such as Teflon.

The Santoprene grades can also be used as a tie-layer to bond two or more incompatible materials, and in laminating techniques.

AES’s enhanced-bonding TPEs provide characteristics of sealability, corrosion resistance and sound and vibration damping to a variety of metals. Opportunities exist for the automotive market, gaskets and washers, office partitions and sound-dampened metal for numerous transportation applications.

One of the largest markets for these TPEs is the window and door industry. Enhanced-bonding TPEs extruded with anodized aluminum are an alternative to extruded vinyl products for window applications.

The materials are reported to offer lower component cost and weight and faster processing than competitive materials. The TPEs are easy to color and have good abrasion resistance, and are currently available in Shore 65A, 80A and 85A hardnesses.

Overmolding onto acetal

A specially crafted combination of acetal copolymer and thermoplastic elastomer (TPE) is the first commercial polymer system to allow injection molders to overmold soft surfaces onto acetal. Designers can now add long-lasting seals, gaskets and non-slip and energy-absorbing elements to acetal components.

The patent-pending technology, which was developed jointly by Ticona and Kraiburg TPE, matches Ticona’s Celcon or Hostaform acetal copolymers with a tailored grade of Kraiburg’s Thermolast-K SEBS, an adhesion-modified styrene block copolymer. The bond between the Celcon or Hostaform acetal and the SEBS is formed during two-component molding and exceeds the tear strength of the elastomer.

According to Ticona, the hard-soft technology has broad application in areas such as automotive interiors, material handling, plumbing, heating and air-conditioning, power tools, medical devices and audio systems.

It allows manufacturers to consolidate parts, which reduces handling and assembly costs. “We estimate savings as high as 30 percent versus conventional assembly methods, especially for large or high-volume components. The system also increases design flexibility by allowing hard-to-assemble parts, such as complex gaskets in fluid handling systems, to be molded in place,” says John Caamano, marketing specialist for Ticona.

Using AES’s Santoprene enhanced-bonding grades, Saint-Gobain Performance Plastics, Specialty Hose Systems is manufacturing carpet-cleaning hose made from a TPE and synthetic fibre, providing enhanced temperature resistance and lightweight properties. The company’s Synflex Super-Clean hose weighs two-thirds less than a typical wire-braided rubber hose.

Advanced Elastomer Systems 800-305-8070

Ticona 908-598-4207