BG Plast has specialized in designing and manufacturing calenders for the production of thermoplastic materials. These machines are the core of the extrusion process for the production of films and sheets. Features include a precision electromechanical control on roll opening and closing which guarantees thicknesses from 0.1 to 40 mm, depending on material.
Closing force expressed in kg/cm is different according to type of polymer, being set by the size of the hydraulic pistons used for moving the rolls (between 80 and 120 kg/cm). A separate thermoregulation unit controls water/oil flow and temperature for each roll. Independent motor-reducer drive for each roll.
In case of very thin sheets there is a particular device called “cross-axis”, shifting the lower roll shaft in relation to the other rolls, to improve thickness regulation. This proves to be quite useful to assure uniformity of sheet thickness.
Sizes of BG Plast manufacturing lines and calenders vary according to the final product required by the customer. The witdh range of calender roll stacks goes from 450 mm to 4800 mm. Thanks to different type of feed-block configurations, BG Plast has faced several co-extrusion applications using up to 7 extruders.