Rubber coated fabrics can be "rubberized" in two methods utilizing large processing machines called calenders. Passaic Rubber Company has 3 processing lines (CALENDERS) that can coat a variety of fabrics with rubber for several different applications. Currently we can calender rubber and rubber coat fabrics just over 60" wide.
One method of rubber coating fabrics is called Frictioning:
Frictioning is running the fabric through the nip area of a calendering line when one of the process rolls is turning at a greater speed then the other rolls. This pushes the rubber into the interstices of the fabric without adding to the overall thickness of the fabric. Usually it is done to increase adhesion between plies. If only one side gets rubberized it is called "single frictioned". When both sides of the fabric get frictioned it is referred to as "double frictioned".
The other method of rubber coating fabrics is Skimming:
Skimming is running the fabric through the nip area of a calender when all the process rolls are turning at the same speed. Usually skimming fabrics with rubber is done after the fabric has been frictioned to build up the overall thickness of the rubberized fabric. If only one side of the fabric gets skimmed it is called "single skimmed". If both sides of the fabric require an increased thickness of rubber it is called "double skimmed".
The most any fabric can get calendered and coated with rubber is if both sides of the fabric get frictioned and skimmed. Then it is called "double frictioned & double skimmed".
Some customer applications require a combo of double frictioning both sides and single skimming just one side which leaves the fabric fully rubberized with the thickness built up only on one side only.
Ply ups are also available which layer several coated fabric layers together to obtain a build-up with extra reinforcements or to obtain thicker overall coatings.