Recycling Technology for Resins of Machine Enclosure Covers

At present, the total annual demand for resin materials used for machine enclosure covers is estimated to exceed 100,000 tons, and those materials must be effectively recycled toward realizing a recycling-oriented society. In addition, Eco-label certification standards recommend the use of recycled resin materials for more than 5% of the resins used for enclosure covers attached to multifunction machines and printers.

However, most polycarbonate (“PC”) alloy resins used for machine enclosure covers contain phosphorous flame retardants, which have posed an issue in recycling resin materials since these flame retardants accelerate the deterioration of recycle resins.
After studying the optimization of material design for recycle resins, Fuji Xerox has now succeeded in incorporating PC alloy resins (with phosphorous flame retardants) collected from the market into virgin resin in amounts up to 20%.

In the material recycling of PC alloy resins containing phosphorous flame retardants, material design that ensures necessary impact resistance for enclosure covers becomes very important. It is known that the impact strength of resin materials can be improved by absorbing the shock energy with voids generated inside the resin by impact. Utilizing this mechanism and observing the voids generated by the impact, optimum virgin resin for the collected resin has been selected.
As shown in Pic.2, Virgin Resin B has a wider void occurrence area than Virgin Resin A (shown in Pic.1), indicating that shock energy has been further dispersed and absorbed in the optimum resin combination.

Furthermore, it is essential to ensure the flame retardant capability for the enclosure covers. Although additional flame retardants reduce impact strength, equivalent impact strength or higher is achieved for recycle resins, compared with that of virgin resins as shown in Fig.1, by mixing a shock buffering agent containing a rubber component such as elastomer into the resin.