Preparation: It is a good chance to maintain the extruder when you replace your conical twin screw and barrel. Please clean up the extruder before installing new screw and barrel and make sure that the extruder’s body frame is horizontal with ground.
Release all heaters from the screw barrel and the connector before installation.
Make the barrel parallel with the frame of machine.
Notice: Make sure your big nut is suitable for the barrel and can be tightly installed.
Make the internal clearance between screw and barrel 0.25mm. Take backwards of screws to the side of gearbox for 4-6mm after pushing it tightly to the barrel small sides.
Make sure that the two screws are symmetrical when you insert them to barrel.
Push screw tightly to the small side of barrel.
Observe the position of screw after pushing it tightly, normally the screw head isin the same level of barrel, sometimes it will be longer or shorter than barrel for 1-2mm.
Push screw barrel to the right place with the mouth of gearbox.
Taking screws backwards to the side of gearbox tightly.
Measure the screw backward distance, we assume that the distance is 22mm. If the screw was in the same level with barrel in the step 1, make the thickness of screw plug 17mm (22mm-5mm). If the screw was longer than barrel for 1mm in the step one, make the thickness of screw plug 18mm(22mm+1mm-5mm). If the screw was shorter than barrel for 1mm, the thickness of screw plug will be 16mm(22mm-1mm-5mm).
Normally we make the screw plug 17mm thick and you need to adjust the thickness according to your situation.
Screw the screw plug into screw shaft tightly.
Install the big nut to the barrel.
Confirm the position of screws again to see if they go backwards for 5mm. (4-6mm is OK)
The most important thing is that you need to push screw backwards to the side of gearbox before you start the machine. Otherwise the screws will go forward to the barrel small side when you start machine.
Observe from the feeding hole to see if the clearance between two screws is equal.
Do not operation the extruder without feeding material, otherwise the screws will go forward to the barrel small side and can not be moved anymore.