Arnitel EL250 – the most reliable solution for soft touch

Arnitel EL250 is softer than almost all other copolyester elastomers and has all the properties needed to respond to the challenge:
■ One of the softest COPE elastomers with a 25 shore D hardness (75 shore A)
■ Combined with easy to mold processing (high flow, fast crystallization, good release, low melting point)
■ Excellent colorability and excellent white base color, good UV resistance
■ Excellent adhesion in 2K on most polar engineering plastics
■ Reliable soft touch for nearly all applications
■ High friction that results in good grip and anti-slip performance
■ Good wear resistance (2 times better than SEBS)
■ Suitable for direct contact with food and potable water (i.e. for all consumer articles)
■ Better chemical resistance than other TPE’s
■ Good set properties and high elasticity

Arnitel EL250 exhibits a hardness of 25 Shore D (similar to 75 Shore A), and is one of the lowest hardness grades in the industry. It offers a real and reliable soft touch, being under the critical hardness threshold for a consistent soft feel and is much easier to mold than other comparable COPE materials. This dra-matically increases the design freedom of designers and application engineers when developing a product.

Arnitel EL250 is a solution provider, offering excellent adhesion on most polar engineering plastics (PC, PC/ABS, ABS, PBT, PET, etc.).

Arnitel EL250 exhibits adhesive strengths on polar engineering plastics of between 8,000 and 10,000 J/m2 according to the substrate and processing conditions chosen. At these levels cohesive fracture occurs, indicating that the interfacial strength is as good as the internal strength of the Arnitel. As indicated, adhesion is influenced by the processing conditions used (see figure 1). DSM can advise in choosing the right conditions that will optimize adhesion for Arnitel EL250 on selected substrates. Arnitel EL250 can also be used in blends with SEBS materials to produce compounds that are still softer but which do have acceptable adhesion to polar engineering plastics. In such blends, Arnitel EL250 provides the basic adhesion to the substrate, provided its proportion is high enough.

When design is important, parts must not only perform well – in terms of use and feel – they should look good too. Arnitel EL250 has an excellent white natural color and good color stability. That gives the widest flexibility for in-mold coloring, allowing the soft tactile component to be accurately color coordinated to the substrate across a broad range of colors. Special house and brand colors can be more accurately matched than with other materials, giving greater consistency in your house style.

Arnitel EL250 has good UV color stability, so that appli-cations where parts can be exposed to some UV radiation will maintain their designed in color, provided the pigments used also have good stability.

Arnitel EL250 has consistent white colour unlike some other competitive COPE's (see insert)

Arnitel and Arnitel based SEBS compounds Figure 4 Abrasion data (DIN 53156) in general outperform standard TPE-S and TPE-V’s on abrasion resistance. Arnitel EL250 has a high friction resistance, so it exhibits good grip and anti-slip performance.

Abrasion data (DIN 53156)

Arnitel EL250 provides excellent processing characteristics, which are crucial in overmolding applications. Best in class flow, to ensure good and fast filling of long flow paths and thin wall sections commonly encountered in overmolding applications. Thanks to Arnitel EL250's low melt viscosity. Next to the excellent flow of Arnitel EL250, its fast crystallization speed and low melting point contribute to easy demolding behavior and short cycle times bringing economic advantages over typically all other TPE families (TPE-S, TPE-V and TPE-U's).

Compared to competitive materials, COPE's Arnitel exhibits the lowest viscosity

Typical cycle time comparison 25 shore D TPE's

Key property data