Handy Hints
Polyurethane Foam
Polyurethane foams such as the Flex Foam-It range all tend to have common challenges when it comes to getting the best possible results. Our technical team often hear comments such as "the foam doesn’t rise as much as it says in the instructions" or "the foam shrivels after de-moulding" or "I don’t know how to work out the foam rise." Here are three hints to help:
- Low Rise – a common problem when the foams are too cold. It is important to heat the foam before use to at least 20 degrees C.
- Shrivels after De-mould – this is due to gasses during curing becoming trapped in the cell structure. To solve this problem, de-mould the foam and crush it several times — this expels the gasses and replaces it with air.
- Calculating Foam Rise – The easiest way to work out the rise of a foam is to take the density of a foam (such as 48kg per metre cubed) and then divide it into a thousand: e.g. 1000 divided by 48 = 20 times rise.
This hint appeared in our Spring 2011 Broadcast Newsletter.
