New elastomer puts B.C. footwear company on fast track
Canadian Plastics
Botex Industries Corp., a Langley, B.C.-based manufacturer of footwear components for the athletic and casual shoe industries, has entered a research and development agreement with Converse Footwear t...
Botex Industries Corp., a Langley, B.C.-based manufacturer of footwear components for the athletic and casual shoe industries, has entered a research and development agreement with Converse Footwear to create shoe parts with a promising new elastomer material Botex has developed in-house. According to Botex vice-president marketing and sales Doug Sheridan, Converse is interested in developing new products with the elastomer because the material will lower tooling costs, reduce overhead and shorten cycle time in comparison to rubber and urethane materials currently used.
Sheridan says the material was originally created by Kevin Parkinson, vice-president research and developement, for use in a water shoe that could be worn for protection while training for barefoot skiing. He describes the material as an elastomeric compound with a phthalate-free plastisol base. It can be formulated with a durometer hardness range of 30 to 85 Shore A, and a density ranging from 0.4 to 1.3 g/cc, in solid or foamed forms.
“Before, if you wanted a cushioning-type system in shoes, you had to go to a foamed urethane, and if you wanted high abrasion resistance you had to use rubber,” says Sheridan. “By adjusting the formula, our material can work in both cushioning and abrasion applications.” The plastisol-based formulation also provides the material with enhanced UV-resistance and weatherability properties in comparison to rubber.
In production, the molten material is gravity fed into an open cavity or cavities. A mating-half of a mold is positioned over the cavity, but no compression or pressure is used in the process, thereby significantly reducing tooling complexity and costs. The net result, says Sheridan, is a much higher production capacity per dollar of capital investment than a comparable compression or injection molding operation.
A combination of the material’s properties and low-pressure molding process provide the user with another advantage: the ability to form multiple-density, multiple-color parts from a single cavity. As many as three to four colors or densities can be used in one cavity without risk of losing the distinctiveness of any one layer.
“With rubber, the more colors or phases you introduce, the durometer range of the layers start to blend together,” says Sheridan. “This technology allows us to isolate, say, the soft parts of the out soles for cushioning from the hard parts of the out soles for abrasion.”
Botex’s current customer base is in the sports footwear, apparel, sports equipment, industrial component and other industries. In addition to using the material and production process at its Langley facility, Botex is licensing the technology to outside companies.