A weared screw can gives several problems such as poor quality of melt, poor flow. In such cases it may be convenient, instead of replacing it with a new one, to repair it. This operation is possible in most cases and leads to very advantageous results.
Alloy for screws
|Type of alloy||Apply||Alloy base||Hardness (HRC)||Wear resistance||Corrosion resistance|
|Stellite 12||Plasma – TIG||Co||45-49||Good||Good|
|Colmonoy 56||Plasma – TIG||Ni||52-56||Good||Very good|
|TIG 5||Plasma – TIG||Fe||58-62||Very good||Good|
The weared plasticizing unit is carefully checked visually and then we proceed with checking the internal diameter of the cylinder along all its length and to fill out a report where the measurements taken are shown as a graph. A careful evaluation of the type of wear, its location, the materials of construction of screw and barrel, allows to make a economically advantageous proposal for revision.