Abstract: Many synthetic latices are produced with a small particle size. It is desirable to increase the particle size and concentrate the latex. It is known to use agglomerating agents to increase particle size. The temperature of agglomeration may be reduced if the latex is destabilized with a weak acid, preferably carbonic acid. This results in an energy saving for the process.

Abstract: A method of making sound insulating floor or wall covering in which carpet is backed with a layer of sound insulating material and a layer of contour retaining material for holding the covering in a desired contoured shape. The latter material, which is conveniently a carpet precoat, is made formable for instance by heating, the carpet and its backing is shaped to desired form, and the retaining material is allowed to set thus holding the carpet and sound insulating layer to that shape. Desirably, the insulating material is a curable rubbery polymer which is cured before carpet shaping takes place. For improved sound insulating properties, deaerated insulating material is used.