Breaking down costs – EPDM Gaskets

Connection Box Gasket

Today’s cost breaking exercise concerned simple 20mm thick 70sh EPDM gaskets with 8mm Ø holes and 10mm wide wall.

The customer was looking for batches of 500 to 1000 at a time and is currently having them water-jet cut.

For short quantities and testing, we can certainly make parts by water-jet – however these have their own issues:

• 20mm solid EPDM is generally only stocked in roll form – when cut this material ‘remembers’ its form and the cut parts can often be banana shaped.
• for flat moulded sheet, there is normally a minimum batch production required – in this instance, enough to cut the 1000 gaskets the customer needed!
• Water-Jet cutting is not a cheap option for higher volumes – especially at 20mm thick when abrasive cutting is best and even multi-head machines are relatively expensive.
• last but not least – the waste involved with all those centres of 20mm material would have to go for grinding, with the various handling charges involved.

So – we quoted prices water-jet cut, as the customers current supplier – but also took a step back and looked at what other methods we could use.

CNC routing the part, although much faster than water-jet, is also far too slow with a relatively high manufacturing cost, and tools tend to burn out faster than expected with rubber!