Waste reduction in plastics manufacturing with polycarbonate/polycarbonate blends

Operation Clean Sweep (OCS) is a product stewardship program of the Plastics Division of the American Chemistry Council (ACC) and The Society of the Plastics Industry, Inc. Spilled plastic resin pellets can result in workplace slip hazards, potential regulatory violations, and impact the environment if discharged from facilities to storm drains, waterways and eventually to oceans. Preventing pellet loss also helps operational efficiency, as more material becomes product rather than waste.

Preventing pellet loss

The main goal of the OCS program is to work toward zero pellet loss and the guidelines are simple--contain, reclaim, and/or dispose of resin pellets properly. Under Operation Clean Sweep, every plastic resin handling operation strives to implement good housekeeping and pellet containment practices. From production to processing, employees play a key role in identifying where pellet loss can occur and how it can be prevented. Ongoing employee vigilance helps support a clean, safe environment--inside and outside of the plant.

Covestro LLC is an Operation Clean Sweep program supporter and partner, and we encourage our customers and others handling resin pellets to support this program as well. More information about Operation Clean Sweep, including pledging and practical implementation tools for employee training, facility audits, worksite setup etc. can be obtained at http://www.opcleansweep.org/.

Recycling of Covestro polycarbonate regrind

Regrind from Covestro polycarbonate products and blends (e.g. Makrolon, Bayblend, Makroblend, Apec) can be used in closed-loop processes. Where end-use requirements permit, up to 20% polycarbonate resin regrind may be used with virgin material. In unique cases where a customer's application may require greater than the recommended level of regrind, the impact on the specific application and its acceptance would have to be determined by the customer. The regrind material must be kept free of contamination and properly dried.

Any regrind used must be generated from properly extruded or injection-molded parts, trimmings, and/or film. All regrind used must be clean, uncontaminated, and thoroughly blended with virgin resin prior to drying and processing.

Under no circumstances should degraded, discolored, or contaminated material be used for regrind. Materials of this type should be properly discarded. Improperly mixed and/or dried regrind may diminish the desired properties of polycarbonate resin.

It is critical that finished parts produced with any amount of regrind be tested to ensure that your end-use performance requirements are fully met. Regulatory or testing organizations (e.g. UL) may have specific requirements limiting the allowable amount of regrind.

Note: Because third party regrind generally does not have a traceable heat history or offer any assurance that proper temperatures, conditions, and/or materials were used in processing, extreme caution must be exercised in buying and using regrind from third parties. The use of regrind material should be avoided entirely in those applications where resin properties equivalent to virgin material are required, including but not limited to color quality, impact strength, resin purity, and/or load-bearing performance.

Covestro LLC customers can contact appropriate personnel for additional information or assistance.