However, these technologies exhibited compromised performance—poor damping, increased weight and adding cost—which has limited its success.
Now the wheel is being reinvented in a so-called Non-Pneumatic Tire (NPT), offering uncompromised performance with DSM’s Arnitel—a family of thermoplastic elastomer polymers and compounds based on block copolymers of polyesters and polyethers. Arnitel is a lighter, greener alternative to conventional rubbers, therefore, reducing environmental impact.
A non-pneumatic tire combines the functionality of the wheel and tire in one concept. It typically consists of a metal central hub, interfacing the axle, an elastic Arnitel “web” structure and a rubber thread on the outside.
What does this mean for tire manufacturers with customers in the construction, agriculture and specialty vehicle industries? By building a non-pneumatic tire instead of a traditional tire, their customers will save money associated with maintenance and downtime when fixing flats.
Also, unlike a traditional tire that wears out quickly—especially when utilized on rough terrain—Arnitel has an extended service life up to three times longer. Plus, a non-pneumatic tire absorbs more impact energy during operation, which makes for a smoother ride on rough surfaces. Other benefits customers will experience are related to the ability through design to optimize the relationship of a harder rubber tread surface and the energy absorbing Arnitel web for improved wear performance without jeopardizing ride quality and reducing turf damage.
Arnitel is well suited for non-pneumatic tire applications because of its outstanding mechanical performance (flex fatigue endurance, high load bearing capability, excellent dynamic creep resistance, high tear and abrasion resistance, and high impact strength). These mechanical properties are combined with Arnitel’s thermal properties, making it perform consistently under all foreseeable climate conditions; a wide operating temperature (-30 to +100°C), extremely low temperature ductility (<-40°C); and stable modulus as a function of temperature. Additional benefits are good resistance to weathering, chemicals, hydrolysis and microbial.
A high-performance TPC
Besides Arnitel being an excellent high-performance thermoplastic copolyester (TPC) for non-pneumatic tire applications, it has an excellent track record in other applications defined by a high load bearing capability in static and dynamic applications thanks to its superior creep resistance and fatigue life as a function of temperature versus rubber or other TPEs.
This high-performance TPC can fulfill and even exceed applications’ demands traditionally served by conventional rubbers. It has been successfully used as a replacement for not only rubber, but also metals (i.e. springs), leather and other thermoplastics because of its versatility in chemistries, hardnesses and superior properties, enabling system cost and weight savings.
From shoe midsoles to taps, dispensers and more
DSM offers a broad Arnitel portfolio, including Arnitel Eco grade, a high-performance thermoplastic co-polyester (TPC) made partially from a renewable source. Each grade is designed to meet specific requirements, including grades suitable for injection molding, extrusion and blow molding.
Applications Arnitel is utilized in include bed springs, taps and dispensers, jaw couplings spiders, coiled cable, furniture (suspended seating), railway pads and train buffers. A newer application is in a fully thermoplastic high-resiliency foam for athletic shoe midsoles. Benefits of using it in shoe midsoles are a high rebound rate up to 80%; consistent performance as a function of temperature; low compression set; resistant to UV-light and heat; homogenous closed cell structures; and a low density (<0.2). Sustainability benefits are clean foaming technology, zero toxicity and recyclability.
Arnitel is supported by a global team working on new ideas and applications and exploring new markets. To access additional data and technical specifications, visit plasticsfinder.com.