Polybrite's Unique plastics plating Technique - direct metallization plastics plating - Brief Article - Statistical Data Included

Automotive Finishing, Fall, 2001 by Beverly A. Graves

Polybrite wanted to develop a different way of plating plastics rather than using the traditional methods. Through research and development it produced a process whereby the plastic is directly metallized...

never a company to shy away from innovation, difficult projects or the opportunity to differentiate itself from other automotive OEM suppliers, Polybrite, a division of Decoma International, the world's largest supplier of exterior products and components to the automotive industry, wanted to develop a unique way to plate plastics. "We wanted to differentiate ourselves from all the other big plastic platers, most of which were using electroless copper," noted Mike Brett, general manager of Polybrite (Richmond Hill, Ontario).

Polybrite could have chosen to use the "tried and true" plastics plating method on the grilles, appliques, headlamp housings and other exterior trim pieces it plates for Ford, GM, DiamlerChrysler, Toyota, Honda, Nissan, Volkswagen, BMW, Isuzu, Rover, Jaguar and Audi. However, the company is recognized throughout the industry as a leader in the development and application of new and groundbreaking methods and materials for the production of exterior vehicle plastic parts and systems. Because of this, Polybrite partnered with Atotech to develop a direct metallization plastic plating process for plating chromium directly on ABS and ABS plastic blends. Polybrite set up a prototype line in its facility for developing the process.

Prior to its move into plastics plating, Polybrite plated copper nickel chrome on metal grilles and exterior pieces. It also did black and clear anodizing. It maintained these processes and simply added the direct metallization process to its list of services. When Polybrite started plating plastics, it processed aluminum and plastics on the same copper nickel chromium-plating line, each with separate pretreatment processes; however, the plastics plating business soon escalated. That was when the company decided to separate the metal and plastic finishing operations into two buildings, naming the aluminum finishing division Anotech. The move occurred in 1998, and Polybrite has continued to grow. The 50,000-sq-ft company uses every inch of the facility and has an additional 50,000-sq-ft building just for storage and assembly.

(Anotech has also continued its growth, as Terry Ball, president of Decoma Exterior Trim explained, "We are very excited about a technology enhancement for black anolok that will triple the durability of today's system and provide improved finishes for our OEM customers. Anotech's enhanced plating anolok capacity will allow us to bring on additional large OEM customers.")

Although space wasn't an issue when the Futuron direct metallization process was installed, its need for less floor space has helped as Polybrite has grown. Direct metallization requires fewer processing steps than plating on plastics using electroless copper, since the electroless copper, copper strike and subsequent rinse tanks are not required. However, shortening the line physically also shortens process times by up to 30% compared to conventional plastic plating processes.

"The greatest advantages of the process, as we see it," noted Mr. Brett, "are that it doesn't plate out on the racks, it has a very stable chemistry and you can interrupt the process after what we call the Cu-Link step." The Cu-Link is a proprietary alkaline process whose function is to chemically replace the tin on the palladium/tin alloy with copper. The resulting film is conductive and makes the surface ready for acid copper plating. "We can take the parts out of the solution at this point and leave them for a day. Granted, we don't want them sitting out for long periods of time due to contamination, but if the process needs to be interrupted, it can be," continued Mr. Brett.

"Another significant benefit of the process at the time we installed it was with the waste treatment. The process contains no formaldehyde," noted Mr. Brett. None of the solutions in the process contain complexing agents such as EDTA or ethylene diamine, nor does the process contain formaldehyde or sodium hypophosphite. Because of this, rinse waters do not need to be treated separately, lowering the volume of wastewater.

The biggest advantage Polybrite has with the direct metallization plastics plating system is its proprietary development of plating on plastics other than ABS, such as ABS/PC blends. In conjunction with its supplier, the company is in the process of developing a chrome-plated thermoplastic olefin (TPO) material that is lighter and less expensive than materials currently used. "We never could plate TPO, and now we have developed a way to plate it using proprietary cycling times. We are also working on ways to plate other hard-to-plate plastics," commented Mr. Brett. "Automotive manufacturers want the flexibility and light weight of plastics, but they want to keep the chrome look and the impact performance you get from steel. We are developing ways to bring all of these characteristics together."