LONDON—Thermoplastic elastomer compounding group, Hexpol TPE, has added new compounds to its Dryflex Green family of bio-based TPEs, creating more opportunities for sustainability. Dryflex Green is a family of thermoplastic elastomer compounds based on raw materials from renewable resources such as plant and vegetable crops.
Raw materials can be produced from various renewable sources. These include products and by-products from agriculture that are rich in carbohydrates, especially saccharides such as grain, sugar beet and sugar cane.
Hexpol TPE has developed several new customization options for the Dryflex TPE compounds.
The hardness range has been expanded to include 20 Shore A to 50 Shore D, with amounts of renewable biocontent to more than 90 percent, depending on the hardness.
“One of the key challenges we faced with the Dryflex Green TPE compounds was to develop low hardnesses with high levels of renewable content, since most bio-based raw materials in the market are quite hard on their own,” Thomas Koppl, manager of the central technology and development center at Hexpol TPE said. “We have now added lower hardnesses to the Dryflex Green range while at the same time maintaining mechanical properties.”
Hexpol TPE additionally has developed compounds using organic fillers and natural fibers from plants, crops or trees, including cork. Cork is a natural product which comes from the bark of the cork oak tree.
The removal of the bark does not harm the trees and the bark is only harvested after the first 20 years of growth. The removal stimulates a steady regeneration of the bark. Each cork tree provides, on average, 16 harvests over its 150-200 year lifespan.
“For customers that want biobased products that also have a natural look and feel, the use of cork and natural fibres helps to give an additional ‘organic' appearance,” Klas Dannäs, global research and development co-ordinator at Hexpol TPE said. “With these new developments to the Dryflex Green TPE range, using different renewable content and covering a greater hardness range, we have created more design and sustainability possibilities.”