Foaming Agents for Gel and Non-Gel Foamed Backed Products

Manufacturer: We are manufacturing products backed and coated with natural rubber latex foam using both "Gel foam" and "Non-Gel foam" systems. What foaming agents do you recommend?

John Woon (Senior Latex Consultant): For gelled foam based on either zinc/ammonia complex or zinc/sodium silicofluoride, you can use fatty acid soaps one good example of which is potassium oleate. You can either buy the ready made soap or make your own by reacting oleic acid with potassium hydroxide. Other possible soaps are caster oil soap and rosinates.

For non-gel foam, it is best to use anionic and non-ionic surfactants such as sodium dodecyl sulphates, sulphonates and non-ionic polyethylene oxide condensates. Do not use non-ionic foaming agents for "gel foam" as these would retard the gelling of latex.