New adhesive for e-motors

Louise Davis

DELO Industrial Adhesives has developed a new epoxy resin. The DELO-DUOPOX SJ8665 two-component product provides flexibility and reliability in the production of electric motors in a medium temperature range.

The adhesive features increased strength for this area of application. With 16MPa on aluminium at a temperature of 80°C, for example, it offers double tensile shear strength compared to standard 2C epoxy resins. In addition, its temperature stability allows for low ageing rates. Bond strength remains the same, even after 1,000 hours being stored at 85°C with 85% humidity.

This tough-hard adhesive of medium viscosity is particularly well suited for surface magnets which are subjected to sudden loads. Furthermore, it can be used for buried magnets and for fixing the stator to the housing. Industrial sieves which are constantly exposed to high temperatures represent another possible field of application.

Even though 2C epoxy resins cure at room temperature, it is possible to accelerate this process by heat. In the case of the new epoxy resin, it easily cures at varying times and temperatures, helping make the production process as fast and flexible as possible. Functional strength is achieved within five minutes, with full curing within 10 minutes, both at 80°C. When induction cured at 100°C, DELO-DUOPOX SJ8665 reaches a strength of 10 MPa within one minute. With final curing of the adhesive done at room temperature, this makes it possible to directly continue the production process.

In contrast to one-component products, which need higher curing temperatures of 130°C or more, DELO-DUOPOX SJ8665 is also used when bonding temperature-sensitive materials like plastics and magnetised metals. Because it can be cured at 80°C, less time is needed to heat components which allows for faster assembly and a lower demand on energy.