Floating Knife and Air Knife Systems
topic
Floating knife systems rest the knife blade directly on the substrate surface without a rigid backing roll, allowing the knife to follow substrate thickness variations and producing a coating layer of uniform thickness above the substrate surface regardless of local substrate thickness variation, while air knife systems use a high-velocity air jet at 0.5 to 2 bar to level and spread coating compound applied by a preceding nip or kiss roll for thin coating applications.
Role
Addresses the limitation of fixed-gap knife coating on substrates with significant thickness variation by floating the knife on the substrate surface that provides uniform coating thickness independent of substrate irregularities, with floating knife coating being used for foam and nonwoven substrates where thickness variation would cause excessive coating weight variation with fixed-gap knife systems.