Secondary Backing Systems

A secondary backing system adds a second backing fabric to the back of tufted carpet. First a precoat of latex filled with calcium carbonate is applied to the carpet back; it locks the pile loops into the primary backing. The secondary backing is laid onto the carpet back while the coat is still wet and tacky, and joined to it between pressing rollers. An Action Back (woven polypropylene) secondary backing gives the carpet strength and resistance to stretching; a felt secondary backing gives it padding and insulation. The result is a carpet with high dimensional stability that lies flat and does not delaminate.

In the example line the carpet takes its precoat after the J-box (3) at the applicator (4), the COALIS coating machine. The lamination feed unit (5) unwinds the secondary backing onto the carpet; the two layers pass the stenter chain entry rails (6), are pressed together between the nip rollers of the embossing unit (7) and dry in the stenter (8). Tufted carpet needs the stenter: it holds the carpet by its edges with pins or clips and keeps its width, preventing shrinkage and distortion as it dries. The carpet is cooled (9), edge-trimmed (11) and reaches the accumulator (12).

The line in the drawing is an example with a working width of 4200 mm and a four-chamber gas-fired stenter. The coating method, the type of secondary backing and the drying length are set for your carpet and capacity at the quotation stage; installation, commissioning and process training are carried out by CEMAY engineering.