A surface treatment that extends the life and improves the efficiency of chrome-plating tooling is gaining acceptance by extruders in North America.
Micro Tuff™ developed by Plating Resources, Inc., Cocoa , FL , impregnates microscopic cracks typically found in chrome-plating with a special compound. The process toughens tools, lubricates extrusion and hikes productivity.
Chrome-plating imparts corrosion and abrasion resistance to tools, and is most widely used with polyvinyl chloride, which releases corrosive acids during processing.
One drawback has been the need to frequently re-plate, which can result in increased downtime, tool damage, and high cost penalties.
Conventional solutions to these problems use to be nitration coating, and fluoropolymer coating. But these all incur higher costs or performance deficiencies. Plating Resources, Inc., however, says recent twists in its technology make its process cost-effective. The company’s technology, once licensed, is now applied directly by the extruder using a convenient kit. Application is feasible during finishing, with-out special equipment.
Users report a shift to the technology in siding, profile and pipe extrusion.
Hard chrome plating typically deposits a 0.7 to 4.0-mil. protective layer on extrusion tools, particularly dies and die lips, screw tips and ends, rollers, barrel adapters, coextrusion blocks, mandrels and slider valves.
A limit has been process generated stresses that cause microscopic cracking of the surface. PVC penetrates and “furrows” these, slowing extrusion, damaging tools, creating dead spots, and pushing up scrap rates.
But Plating Resources’ compound (which includes an organic penetrator, and a bonding polymer) polymerizes at the time it is applied, and penetrates and bonds to the crack faces.