posted 10-08-2002 03:58 PM
We have a 80 mm diameter ventilated screw. The motor is 50 HP and the RPM of the screw is 63. The hr output for ABS and HIPS is 80 kgs. I would like to know if there is something we can do to increase the output, because I´ve heard that for our machines´ design and characteristics the output should be more than what it is now.
posted 10-10-2002 05:10 PM
You should be able to reach 100 to 110 kgs/hr at 63 RPM with approporiate design. As well, should amperage allow, max speed could be increased to yield more rate by changing the belt and sheave arrangement.
posted 10-10-2002 09:48 PM
With ABS I would initially try lowering the first zone temperature. Find a setting which gives you the most amps. Then lower the first transition zone until something bad happens (I accept no responsibility for the multitude of bad things that could happen). Then raise the first transition zone a bit so that the problem goes away. You should then be near maximum rate for your current screw and RPMs.
Barrier screw do not respond much to the transition zone adjustment.
posted 10-11-2002 05:05 PM
Another of one our associates weights in. The output of 80 kg/hr is about would be expected for a 80mm two stage screw turning at 63 rpm. You has plenty of HP but not enough rpm. in order to get more output the rpm of the extruder must be increased. If it is a belt drive its just a matter of changing sheaves as suggested above. If it is a direct drive there are several options. First the gearing can be changed. Second the motor could be rewound to 2150 rpm thereby increasing the output by 22%. Finally the drive could be offset with belts and sheaves to accomplish any speed. The last item takes some research however as not all motors or gearboxes have enough radial bearing capacity to handle the side load.
posted 10-08-2002 03:58 PM
