Stover, L., Kenny, P., and Upchurch, M., "Controlling Custom-Colored Automotive Interior Components at the Press," SAE Technical Paper 1999-01-0981, 1999, doi:10.4271/1999-01-0981.
The need to produce molded plastic components for automotive interior applications in a variety of colors, cost-effectively, while maintaining an automaker's exacting color standards is a challenging task. The traditional approach of using pre-colored - and often custom-colored - materials requires a processor to purchase and inventory a high volume of product in order to buy at a competitive price. The other option - of adding color at the press - can also be challenging if the base material's color is prone to vary from batch to batch. Recognizing this situation, a compounder has worked on one solution to help overcome this problem by developing methods for delivering compounded polypropylene resin with a higher level of base-color consistency than was available in the past. These new materials can be paired with custom-color formulations from most colorant suppliers that have been previously color-matched with OEM color specs, and that are specially formulated to work in the new, more consistently colored polypropylene base resin. This solution should help provide processors with the flexibility to color compound just prior to molding, but still maintain tight color tolerances, lot-to-lot and color-to-color.