Fluoropolymer Lubricant
Lubricating agents of this class are incorporated into protective overprint varnishes to lower the static and dynamic coefficients of friction of the finished package. The PTFE slip additives provide surface lubrication that prevents scuffing and scratch damage on high speed filling lines. This addition improves the runnability of cartons through folding and packing machinery.
Particle Distribution
Formulation requires dispersing micronized polytetrafluoroethylene particles uniformly in the liquid ink or varnish before application. During the drying process, these low surface energy particles migrate to the outer boundary of the cured film. This migration creates a slick surface layer that resists abrasion and prevents the printed sheets from sticking together in the delivery pile.
The particle size is matched to the dry film thickness to ensure that the lubricating particles project through the surface.
Adhesion Risk
Achieving the target slip requires precise dosing to avoid over lubrication, which can cause stacking instability and pallet slipping. If the concentration is too high, the surface becomes incompatible with subsequent gluing and foil stamping operations. These additives do not apply to waterbased inks that do not require high slip characteristics for their end use.
The effectiveness is determined by measuring the slide angle or the static coefficient of friction.
