Starting March 2022, the German Environment Agency (KTW-BWGL standard) has established evaluation criteria for plastics and other organic materials that come into contact with drinking water. These criteria will also apply to thermoplastic elastomers (TPE), with a three-year transition period. Therefore, the contact layers of drinking water supply pipes and hoses for household appliances, such as dishwashers, must also meet these requirements by March 2025.
"Through our new THERMOLAST® DW/H2 series, we are supporting customers who are committed to supplying sanitary and drinking water pipes that meet the stricter KTW-BWGL standards. At the same time, we are setting higher standards for the performance of TPE compounds that meet these standards," said Hartmut Arheidt, industry market manager at Keba GmbH. "Innovative material technology makes the pipes have significantly improved tensile strength, tear resistance, elongation at break, and excellent bending resistance."
The new and unique THERMOLAST® DW series replaces the previous DW/H series products and currently offers six different hardness grades, ranging from 70 Shore A to 40 Shore D (see Table I). These compounds can be easily processed on traditional polyolefin extrusion lines and are ideal for efficient production of cold and hot water pipes, providing up to 50% better mechanical properties and excellent performance with PP liners. Furthermore, these TPE compounds also feature an extremely smooth surface, providing resistance to microbial growth as required by EN 16421 (formerly DVGW W270), and do not affect the odor, taste, or clarity of water passing through the pipes.
THERMOLAST® DW/H2 compound expands the potential applications of TPE in this market, particularly for shower pipes, pressure hoses, food hoses, and supply lines in dishwashers and washing machines. They were developed in close collaboration with customers.
"We can also provide test reports that comply with the new KTW-BWGL standards," Hartmut Arheidt added. "These reports confirm that the materials are suitable. We can provide samples for inspection to customers, potential customers, and partners at any time."