AKRON, OHIO - Union Carbide Corp. of Danbury, Conn., is marketing a new line of blended post-consumer resins designed to overcome inconsistencies in color and working properties. Production began this fall of Enhanced Prisma-brand resins at Union Carbide's recycling plant in Piscataway, N.J., products the company touts as having high color integrity.
Displaying the new line at the recycling conference of the Society of Plastics Engineers in Akron on Nov. 2-3, Quentin Eberhart, technologist for Carbide, said the blends come in six different basic colors for high density polyethylene bottle regrind.
``Originally we created our Prisma-brand recycled blends by hand, sorting the materials into the red, yellow and orange category, and blue-green category, but now we engineer the colors by breaking down bottles into small, single-color chips, and then selecting the chips to meet color standards,'' he said.
The Carbide process takes feedstock from a material recovery facility, pre-rinses it in the debaling process, and grinds the commingled material stream. The chips are given multiple washes, and then sorted by color using an automated chip sorter by Simco/Ramic Corp. of Medford, Ore. That step separates chips into six different color categories, and the chips are then extruded and blended.
``Even in multilayer containers, where the [post-consumer content] is the interior layer, the color integrity is improved,'' Eberhart said. ``Our labs color test and certify melt index, density, pellet count uniformity, weight loss, flow index and melt flow ratio.''
Samples of the colors for each individual batch are kept for two years by the company to ensure consistency.
The company converted a PET recycling line at the Piscataway site and added new equipment to the existing HDPE line to accommodate higher production volumes of the Prisma resins, Eberhart said.
