Demoulding Problem of Latex Foam Products

Manufacturer: We are latex foam products manufacturers. Recently we have been having problems of demoulding of our products from the molds resulting in high rejection due to tearing. Your advice would be appreciated.

John Woon (Senior Latex Consultant): All products made from rubbers or elastomers with some forms of moulding should be able to be removed from the moulds easily at the end of each cycle of moulding without undue stress being applied to the products. Your encounter of the demoulding problem could be due to poor cleaning process for the moulds and/or wrong choice of releasing agents.

I suggest you introduce a proper cleaning process to ensure that all surfaces of the moulds are free from the cumulative build-up of non-rubbers from the latex and compounding ingredients.

As for the releasing agents, you can try aqueous solution of sodium carboxymethyl cellulose or it's derivatives and low-molecular-weight polyethylene glycols. You can use either of these or a blend of both. This is best applied by spraying while the moulds are still hot.