Bonding of magnets and pole plates

For magnets bonding, especially with larger diameters, a flexible adhesive with a high temperature resistance is required. Otherwise, it can lead to fractures of the magnets. High temperatures are often experienced within the voice coil. In addition, the magnets (usually made of neodymium or ferrite) are often coated, so the adhesive used must have a good strength on a wide range of finishes. Even coatings made of e-coated or galvanised (zinc-plated) surfaces that are difficult to bond can be bonded with Kisling adhesives. A short cycle time and fast curing is advantageous because the magnets should be activated as soon as possible after bonding. In the past, magnets were usually bonded with epoxies, but nowadays methacrylates are more commonly used. Adhesives from Kisling are a perfect solution. Advantages over epoxies are:

• the products cure quickly and safely even at room temperature
• the flexibility avoids vibrations and stress peaks during temperature changes, which could cause the magnet to break
• due to the universal adhesive properties, many material combinations can be successfully bonded, resulting in an enhanced design freedom
• the wide selection offers you the properties you require
• customised formulation available