Drinking water crises, such as the widespread lead contamination in Flint, Michigan, are making more consumers aware of the health risks that plumbing parts containing leachable substances pose. As a result, manufacturers of residential water system components, including faucet mixing valves and mixing cartridges, are under pressure to use safe and sustainable materials.
Brass has long been a choice material for manufacturing faucet system components, due to its high mechanical strength and hydrolytic performance, as well as its low melting point compared to alternative metals. However, plumbing fixture parts made from this alloy are proven to leach potentially harmful levels of lead. A 2019 study indicates that even brass faucets marketed as “lead-free” may still leach concerning amounts of lead into water during the first few weeks of use.
As regulators in the EU and U.S. implement increasingly strict water contact safety standards, more manufacturers are turning to engineering thermoplastics, which, in addition to leaching zero lead, can substantially reduce production costs. Polyamide 66 and polyphenylene oxide (PPO) are frequently used to manufacture faucet components due to their high strength, reliable performance to price ratio, and compliance with numerous water contact standards.
Yet, long-term exposure to extremely hot or cold water tends to cause these polyamides to deteriorate and may result in leaks that require costly repairs. Since PA66 and PPO provide limited design flexibility, neither material is ideal for developing more complex parts.
Some manufacturers produce faucet components using polyphthalamides (PPA) that offer a low glass transition temperature (Tg). Although these materials demonstrate excellent mechanical performance in hot water conditions, they require high-temperature tooling and provide low ductility – which can make it difficult to mold complex parts. Since PPA, PA66 and PPO aren’t renewable, producing these materials also tends to leave a larger carbon footprint. To meet customer requirements, manufacturers need to select materials that meet water contact standards, maximize end-part reliability and reduce environmental impact.
EcoPaXX® PA410: a safe, and sustainable, high-performance alternative
DSM’s EcoPaXX Q-DWX10 is a bio-based long-chain polyamide made with 70% renewable castor bean feedstock (castor oil). The material’s sebacic acid and diaminobutane structure results in high crystallinity that enables best-in-class low moisture uptake, excellent mechanical strength and the highest melting temperature of any bioplastic solution - making it ideal for water system applications. EcoPaXX also leaves a low carbon footprint, as the CO2 emitted during material production is largely absorbed by castor bean plants.
EcoPaXX Q-DWX10 enhances faucet component reliability due to its unmatched low moisture absorption, high dimensional stability and superior hydrolysis resistance. Testing reveals that the material demonstrates a 30% higher retention of modulus after extensive conditioning in cold and hot water, compared to low Tg PPA. EcoPaXX Q-DWX10 faucet valves also show no leakage after 1 million testing cycles, as well as flexural strength greater than 61Nm. To protect the health of consumers, the material complies with global water contact regulations, including Germany’s widely-usedwidely used KTW-BWGL standard.
A superior drop-in replacement for PA66 and PPO
Due to its high ductility and excellent thermal stability in processing, EcoPaXX Q-DWX10 is a drop-in replacement material for PA66 and PPO, which saves significant re-tooling time and costs. The bioplastic’s high flow allows manufacturers to produce intricate, thin-walled parts that offer high mechanical performance and are easier to demold. EcoPaXX Q-DWX10’s high flow and tailored crystallization speed leads to exceptional surface quality and high overmold stability that improves bonding performance.
Our mission at DSM is to help you meet your customer’s expectations for quality while protecting the health and safety of product end-users. We partner with industry-leading manufacturers to understand their evolving regulatory compliance concerns, as well as how we can optimize our material solutions to exceed your performance and reliability requirements. Building on our success with EcoPaXX, we’re on track to launch bio-based or recyclable versions of all our materials by 2030. Working together, we can protect the health of people and the planet.
03 September 2021
Specialty polymers meet the need for lead-free water contact solutions
Market Development Manager at Envalior
After obtaining his Ph.D. in supramolecular and organic chemistry, Pim Janssen began his career at Envalior as a chemist for the engineering plastics Akulon (PA6) and the biobased EcoPaXX (PA410). He also spent a few years in product development and program management for high temperature polyamides ForTii (PPA), Stanyl (PA46), EcoPaXX (PA410) and Xytron (PPS). In 2018, he joined the business management team as market development manager for water and food contact, industrial applications, and to develop a unreinforced PPA portfolio.
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