DP Seals, the UK’s supplier of precision custom rubber seals and mouldings, has developed tooling incorporating magnets for a rubber-to-metal bonding application.

The innovative tool holds steel washers in place while moulding acoustic washers for Farrat Isolevel, a vibration control engineering company.

DP Seals was chosen because of its extensive tooling knowledge and its in-tool rubber-to-metal bonding capability.

Manufacturing the Farrat top hat washers requires neoprene polymer to flow around and through a steel washer such that there is sufficient rubber to provide the required levels of acoustic isolation. Neoprene’s resilience ensures high levels of acoustic isolation over a long period of time.

To ensure accurate washer positioning during the moulding process, DP Seals built three high-powered 5mm magnets at each product location in the tool.

The number and power of the magnets proved crucial to achieving consistent repeatable, accurate mouldings: too few magnets allowed rubber to flow to the wrong side of the washer, too many or too strong magnets made removal of the (hot) product difficult, resulting in increased wastage.