MACHINERY [ Extrusion ] |
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HDPE waste |
Above : the Tandem Plus line by Gamma Meccanica
Above left : pellets produced on a GM Tandem Plus line
LDPE waste
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extruder with a screw diameter of 90 mm , L / D ratio 44 , two standard degassing stacks , two side inlets for mineral fillers and additives and another inlet for adding liquid additives . Fillers and additives are delivered from a gravimetric blender . At the end of the twin-screw extruder a TDA liquid ring pelletiser , developed and manufactured by Gamma Meccanica , streamlines the cleaning operations during production changes and starting ups , in addition to guaranteeing high production performance . The regeneration and upcycling process begins with the gravimetric blender and the Compac feeder which takes care of shredding and densifying the waste to be recycled . From the Compac unit , the material is then pushed into a constant flow by the extruder screw . The melt obtained during the extrusion process is then filtered by the self-cleaning screen changer that removes even the smallest contaminant particles . At the exit of the screen changer the melt is “ degassed ” in the degassing system in order to avoid defects such as “ air bubbles ” in the pellets . The degassing system is the closed-loop type where the wastewater instead of being disposed of , is passed through a decanting chamber , then filtered and cooled and finally returned to the process . At this point , the material is modified with the addition of masterbatch , carbonate and various additives into the twin-screw extruder . The fillers and additives are delivered from the blender , which guarantees maximum precision in the development of the recipe . The process ends with the pelletiser which cuts the melt into pellets inside the cutting chamber . The line also includes a viscosity control system and a digital weighing machine that controls the productivity of the line . This model has an average production of 1,200 kg / h of modified PE compound . |
Italian technology plast / May 2021 |
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www . plastmagazine . it |
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