Adhesion promoter application system and process

An adhesion promoter application system, comprising:

• a transport device for moving said thermoplastic polyolefin elements through said system;
• a device for mixing an adhesion promoter with de-ionized water to form a mixture;
• an enclosure for providing a protected environment during application of said mixture to thermoplastic polyolefin elements located therein;
• an adhesion promoter application device within said enclosure for flowing said mixture with minimum agitation over said thermoplastic polyolefin elements, said adhesion promoter application device further comprising:
• a gravity tank for holding a supply of said mixture;
• at least one mixture supply header in communication with said gravity tank and located overhead of said moving thermoplastic polyolefin elements, and
• a plurality of gravity-fed mixture dispensing nozzles distributed along the length of said at least one mixture supply header and extending downward toward said thermoplastic polyolefin elements, said nozzles angled in the direction of travel of said thermoplastic polyolefin elements;
• a pump for supplying said mixture to said gravity tank;
• and
• an atmosphere controller for regulating the atmosphere within said enclosure.

An adhesion promoter application system for coating thermoplastic polyolefin elements with a layer of adhesion promoter having minimal defects, comprising:

• a plurality of carriers for moving said thermoplastic polyolefin elements through said system with each polyolefin element angled from vertical toward the direction of travel of said carrier;
• a device for mixing an adhesion promoter with de-ionized water to form a mixture;
• a storage device for storing a supply of said mixture;
• an enclosure for providing a protected environment during application of said mixture to thermoplastic polyolefin elements located therein;
• an adhesion promoter application device within said enclosure for flowing said mixture with minimum agitation over said thermoplastic polyolefin elements, said adhesion promoter application device further comprising:
• a gravity tank for holding a supply of said mixture;
• at least one mixture supply header in communication with said gravity tank and located overhead of said moving thermoplastic polyolefin elements,
• a plurality of gravity-fed mixture dispensing nozzles extending downward from said at least one mixture supply header toward said thermoplastic polyolefin elements and distributed along the length thereof such that the entire surface of said thermoplastic polyolefin elements is coatable by said nozzles, said nozzles angled in the direction of travel of said carriers, and
• a flow regulation means for regulating the flow rate of said mixture through each nozzle;
• a pump for supplying said mixture from said storage device to said gravity tank;
• an atmosphere controller for regulating the atmosphere within said enclosure;
• and
• a drying device for drying said mixture after application to said thermoplastic polyolefin elements;
• wherein agitation of said mixture during application thereof to said thermoplastic polyolefin elements is minimized by use of said adhesion promoter application device, thereby reducing or eliminating defects in a dried layer of adhesion promoter that remains on said thermoplastic polyolefin elements after said thermoplastic polyolefin elements pass through said drying device.