At its traditional press conference in New York in mid December, Dow Plastics (European HQ: Bachtobelstr. 3, CH-8810 Horgen) showed that it is still on an innovation course. In 1998 the group introduced its “Index” series of ethylene-styrene copolymers, a follow-up to 1997´s highlighted “Questra” syndiotactic polystyrene. This year, the spotlight was on the “Blox” polymers, which are being billed as a completely new class of product.

According to product manager David Hatfield, Dow has developed a thermoplastic that combines the adhesion and durability of epoxy resins with the flexiblity and processability of thermoplastics. In other words, a thermoplastic-thermoset hybrid. Two types are to be launched initially.

The first, “Blox High Adhesion Barrier Resins”, are said to combine characteristics such as clarity and mechanical strength with excellent gas barrier and adhesive properties. These are described as suitable in particular for coating PET beer, juice and carbonated soft drink bottles. One of Dow´s first customers is packaging giant Tetrapak, which plans to use this Blox type in its new “Sealica” bottle series set for launch in spring 2000.

The second type of polymer, “Blox Adhesive”, is said to offer superior adhesion, durability and clarity. Hatfield said the resins currently used in starch-based loose-fill packaging and in powder coatings are also targeted for other coatings applications, including hot-melt adhesives, adhesion promoters and polymer additives. Two US companies, American Excelsior and Starch Tech, already use Blox resins to produce starch-based foams that Dow believes can compete with foamed polystyrene.