Sheet Extruder Lines
Machines with 65 mm/75 mm/90 mm main extruder are offered in combination with one of two 40 mm/50 mm co-extruders. The extruders are powered by AC motors with frequency drives. The motor and the extruder gearbox are coupled by V-belt giving in smoother operation. The thrust bearing is located inside the gearbox for best lubrication and heat dissipation. The control panel for the entire line is free standing.
Several different screw designs are offered. The L/D ratio is 1:32 for all screws. Multipurpose screw design for HIPS, ABS and PP is also offered.
The barrel is heated using ceramic electric band heaters controlled by closed loop temperature controllers.
The die is coat hanger type of die with horizontal split line. It has adjustable and interchangeable lips for different ranges of sheet thickness. Dies have a flexible lip or choker bar. The sheet width can be adjusted on either side by deckling if needed.
Polishing Roller Stack:
The surface of plastic melt leaving the die is smoothened and cooled by rollers on passing through a 3 roll vertical polishing stack. The top and bottom rollers of the polishing stack are pneumatically moveable while the centre roller is fixed. The surface of roller is hard chrome plated and highly polished to mirror finish. The rollers are temperature regulated. The rollers are double-shelled type with spiral circulating channels. All the three rollers have separate temperature control circuits.
The sheet leaving the polishing stack moves on flat cooling track for cooling before entering the takeoff and trimming.
Takeoff and Trimming:
After the cooling, sheet is pulled by a set of rubber nip rollers. The polishing roller stack and take off rollers have independent drives. The side edge is trim by a set of circular rotating knives or by fixed knives for thin gauges.
Single or double shaft winders are available as per requirement. For thicker sheets guillotine is provided, with electronic cut-to-length system.
Different co-extrusion systems like A-B, B-A, B-A-B, B-A-C are offered. B-A system is generally used for high gloss layer of GPPS on HIPS sheet with main extruder running HIPS.
Machines are also available with two co-extruders. Barrel Venting is optionally available. Power requirement can vary as per actual system configuration. T-dies upto 1500 mm width are available. Output depends on material used, screw design offered and actual machine configuration. Machines are suitable for ABS, PP, HDPE as well.