As soon as we receive the used screw we carry out the following checks:
- crest diameter
- thread conditions
- coupling conditions
- kernel wear and coupling diameter
The scope of such verifications is to estimate the operations to carry out, in order to bring back the screw to the original level, operating on the wearied parts, ruined or broken off during the use.
The restoration of the original diameter, essential condition to restore the capability to transport the plastic material to the original level, is done by means of welding material on the crest by means of automatic machines that assure a homogenous welding and absence of blows.
After that there is a finishing and final polishing, which assure a final rugosity lower then 0,06RA. There are several materials for repairing and the choice is based on customer requirements.