Process for continuous production of foams using an auxiliary inline mixer

A process for continuous production of a porous water borne foamable resin coating, using a surfactant with higher molecular weight as an additive in an aqueous polymer dispersion, the process comprising:

• a) providing a mixture comprising of an aqueous polymer dispersion, a surfactant with higher molecular weight, and other necessary additives;
• b) foaming the mixture to give a foam, wherein the mixture is mixed in a foaming machine at a mixing head line speed of less than 4 m/s;
• c) mixing the foam obtained from b) in an auxiliary inline mixer connected to the foaming machine of b), at a line speed of a mixing head from 5-30 m/s, to obtain a foam with homogeneous and fine cell structure;
• d) applying a coating of foamed polymer dispersion to a suitable carrier, and
• e) drying the coating.

A continuous production line for production of foams using a surfactant with higher molecular weight as an additive in an aqueous polymer dispersion, the production line comprising:

• a foaming machine with a mixing head line speed of less than 4 m/s,
• a coating device, and
• a drying device, and
• an auxiliary inline mixer capable of achieving a mixing head line speed of 5-30 m/s;
• wherein an inlet of the inline mixer is connected to an outlet of the foaming machine, and
• wherein an outlet of the inline mixer is connected to the an inlet of the coating device.