Adhesion promoter application system and process

A method of improving adhesion between the surface of a thermoplastic polyolefin element and a subsequently applied coating material, said method comprising:

• supplying a mixture of an adhesion promoter and de-ionized water;
• providing an application enclosure, said enclosure forming a protective environment for the application of said mixture;
• regulating the atmosphere within said application enclosure;
• providing said mixture to a plurality of spray nozzles located within said application enclosure;
• locating said thermoplastic polyolefin element within said application enclosure;
• applying said mixture to said thermoplastic polyolefin element via said plurality of spray nozzles;
• regulating, during application of said mixture to said thermoplastic polyolefin element, one or more of a flow rate of said mixture, a discharge pattern of said plurality of spray nozzles, an angle of said plurality of said spray nozzles, a distance of said plurality of spray nozzles from said thermoplastic polyolefin element, and an orientation of said thermoplastic polyolefin element;
• and
• drying said thermoplastic polyolefin element in a drying enclosure after application of said mixture;
• whereby a dried layer of said adhesion promoter is retained on the surface of said thermoplastic polyolefin element;
• and
• wherein the presence of said dried layer of adhesion promoter does not have a detrimental effect on the appearance of said subsequently applied coating material.

A method of improving adhesion between a thermoplastic polyolefin element and a subsequently applied coating material by depositing a layer of an adhesion promoter on the surface of said element, said method comprising:

• supplying an adhesion promoter;
• forming an adhesion promoter mixture from said adhesion promoter and de-ionized water;
• providing a mixture storage tank for receiving and storing a supply of said mixture;
• transferring at least a portion of said mixture to said mixture storage tank;
• providing a mixture application enclosure, said mixture application enclosure having a regulated atmosphere and forming a protective environment around said thermoplastic polyolefin element during application of said mixture thereto;
• providing a gravity tank for receiving a supply of said mixture from said mixture storage tank;
• providing at least one supply header for receiving, via gravity from said gravity tank, an amount of said mixture;
• providing a plurality of spray nozzles in communication with said at least one supply header, said plurality of spray nozzles adapted to be adjustable in location and direction, and to distribute said mixture received from said gravity tank over the surface of said thermoplastic polyolefin element;
• locating said thermoplastic polyolefin element on a carrier;
• cooling said thermoplastic polyolefin element to approximately the temperature within said mixture application enclosure;
• angling at least some of said plurality of spray nozzles in a direction of travel of said conveyor;
• running said thermoplastic polyolefin element through said mixture application enclosure on said conveyor while said mixture is emitted by said plurality of spray nozzles, thereby applying said mixture to said thermoplastic polyolefin element;
• regulating, during application of said mixture to said thermoplastic polyolefin element, one or more of a flow rate of said mixture, a discharge pattern of said plurality of spray nozzles, a distance of said plurality of spray nozzles from said thermoplastic polyolefin element, the orientation of said thermoplastic polyolefin element on said conveyor, and the speed of said conveyor;
• and
• passing said thermoplastic polyolefin element through a drying enclosure after application of said mixture;
• whereby a dried layer of said adhesion promoter is thereafter retained on the surface of said thermoplastic polyolefin element;
• and
• wherein, due to the application of a substantially complete coating of said thermoplastic polyolefin element with said mixture and a reduction in the amount of foaming and splashing of said mixture that occurs during said application, the presence of said dried layer of adhesion promoter does not have a detrimental effect on the appearance of said subsequently applied coating material.