"Certain thin, flaky regrind—like PET bottle scrap or thicker film and sheet scrap—has granules with relatively large, flat surfaces, so they tend to pack together and bridge in conventional hoppers," Bickel says. "By making it possible to easily re-use scrap that wold be next to impossible to process otherwise, the new Conair blender designs can deliver a nice return on investment."
Two new TrueBlend solutions from Conair take different approaches to make processing this regrind more cost effective.
For small quantities, TrueBlend blenders "can be fitted with side feeders with steeply angled sides that help prevent the regrind from hanging up and bridging." An oversize opening at the bottom bottom lets the regrind easily flow through to a horizontal auger that positively conveys the material into the mixing chamber.
For larger volumes, like pipe extrusion applications, "lift augers" are employed to eliminate bridging. The lift augers are placed at an angle in a corner of the regrind bin. Instead of forcing material out of the bin, the augers turn in the opposite direction to lift material up and away from the bottom. This is said to keep the material loose so that it can flow more easily through oversized side gates into the mixing chamber.
The TrueBlend blenders contain all pellets within the mixing chamber, "virtually eliminating waste and improving accuracy." Throughputs range from less than 50 lb/hr (23 kg) to 12,000 lb/hr (5455 kg). Up to 12 ingredient bins can be supplied for an individual unit.