Knife Coating (floating knife) or Direct Coating
In Knife Coating, as seen in Figure 3, the liquid coating is applied to the fabric while being run at tension under a floating knife blade, the distance between the fabric and the knife blade determines the thickness of the coating. The blade can be angled and have different profiles to affect the coverage. For this process to be effective the liquid coating must be quite viscous in order to prevent it soaking through the fabric, the coating is then dried or cured.
This technique is best used for Filament? yarns as the staple fibres in spun yarns can protrude on the surface creating an un-even finish, but this is dependant upon the thickness of the applied coating. For this type of coating to be most successful the weave structure has to be quite tight and the fabric capable of being held taught.