What combines the processing options of a thermoplastic with the end-use properties of a thermoset? Until recently, nothing. But a line of epoxy and amine resins from Dow Chemical (Midland, MI) now brings the opposing thermoplastic and thermoset worlds a bit closer together. Called BLOX resins, these materials "act like an epoxy and process like a thermoplastic," explains David Hatfield, Dow's global business development manager for epoxy products.

"BLOX has combinations of properties never seen before," Hatfield adds. "It displays a flexural modulus and toughness similar to nylon, clarity levels like acrylic or PET, and the adhesion capabilities of epoxy." Some grades also exhibit oxygen barrier properties similar to EVOH. Like other thermoplastics, BLOX resins can be melt-processed in a variety of ways, including injection molding, extrusion, and blow molding. As for processing, Dow will offer the material with different rheological characteristics for grades that process like familiar commodity and engineering thermoplastics--such as PE, PS, ABS, and PBT.

Dow will initially market two lines of these materials: BLOX high-adhesion barrier resins will be targeted at rigid beverage packaging. The second line, BLOX adhesive resins, has a wider range of applications, and will be offered as adhesives, adhesion promoters, and polymer additives. Blended with starch, these materials can be foamed for loose-fill packaging. And thanks to their ability to adhere to metal and other substrates, these BLOX materials have also been used in powder coating formulations. One company, Powdered Flame Spray, has already used BLOX in display-rack and automotive applications.

Because BLOX resins have such a unique mix of properties, Hatfield predicts that even more uses for the materials will emerge over time. "Frankly, we don't think we've begun to understand the wide variety of applications yet," he says.

For more information about BLOX resins from Dow Plastics, Circle569