PETpla.net Insider 05 / 2011

MATERIAL / RECYCLING 27 PET planet insider Vol. 12 No. 05/11 www.petpla.net Insulation for higher productivity A better blend Conair’s insulated high-heat blenders help virgin/regrind PET producers achieve more accurate mixing, cut waste, reduce shutdowns and save energy. Increasing volumes of post-indus- trial and post-consumer recycled PET are being incorporated into products such as disposable food containers and polyester strapping for packag- ing and material handling. Conair, a global supplier of auxiliary equip- ment for plastics processors, says that its new, fully-insulated TrueBlend gravimetric blender can help manu- facturers of products with high levels of recycled material to achieve sig- nificant energy savings and improve productivity. Conair’s high-heat Trueblend blender enables recycled and virgin materials to be kept separate until just before feeding into an extruder or moulding machine. This means that, for example, contamination in recycled PET need not shut down the entire production line. If contamination is discovered in the TrueBlend pro- cess, only the regrind stream needs to be cleaned up and production can continue using 100% virgin resin. Blended virgin pellets and regrind fluff, which have significantly different bulk densities and flow characteris- tics, reach the machine feed throat more quickly and have less opportu- nity to re-separate during conveying. The desiccant drying’s heat input is retained during blending, meaning less additional energy is needed for final processing. Conair’s insulated blenders have up to 2273kg/h capacity. The stand- ard unit includes two material hoppers for virgin and regrind; systems with three, four or more hoppers are also available. Material hoppers are eat- insulated and have a 60° cone angle to encourage mass flow of material. Smooth interior walls ensure that all material spends the same amount of time in the hopper and prevents heat loss and moisture regain. All compo- nents have been specified to with- stand temperatures up to 191°C and higher and electronic components are temperature-isolated. The conven- tional surge bin is replaced by another insulated drying hopper. All piping is insulated and all areas of the blender are blanketed with dry air to prevent moisture regain. The new blender models have a fully enclosed weighing and mixing section and the controlled environ- ment makes the blenders accurate to within ±0.5% of setpoint on material weights. The standard microprocessor control adjusts after every dispense cycle, compensating automatically on the next batch for normal variations in dispensing, resin bulk density and particle geometry. After virgin and regrind are dispensed and weighed they are dumped into a multi-batch mixing chamber. Individual batches are mixed for a set time, averaging out any batch-to-batch differences. The control system has a full-colour 5.7in/140mm LCD touch-screen user interface. All setpoints are displayed simultaneously and after blend per- centages have been entered, the blender automatically weighs the ingredients in the proper sequence and maintains. Up to 50 recipes can be entered and stored in the control for instant recall. Options include an integrated blender/loader control feature. www.conair.com Conair’s high-speed Trueblend gravimetric blender or recycled and virgin materials