How to Repair Screw Barrel?

How to Repair the Blown Film Machine’s Screw Barrel？

1. The broken screw shall be considered according to the actual inner diameter of thebarrel, and the outer diameter deviation of the new screw shall be manufacturedaccording to the normal clearance with the barrel.

2. After the surface of the thread with the diameter of the worn screw is reduced, thewear-resistant alloy is sprayed by heat, and then grinding to the dimension. Thismethod is generally processed and repaired by professional spray factory, and thecost is relatively low,

3. The wear-resistant alloy is deposited on the threaded part of the worn screw. Weld1 -2mm thick according to the wear degree of screw, and then grind the screw to thesize, The wear-resistant alloy is made up of C, Cr, Vl, Co, W and B materials, whichincreases the wear resistance and corrosion resistance of screw. Professional surfacingplant for this kind of processing costs are very high, except for special requirementsof screw, generally rarely used.

4. The surface plating method of hard chromium can be used for repairing screw.Chromium is also a metal with wear-resistant and corrosion resistance, but the hardchromium layer is easy to fall off.

How to Repair a Blown Film Machine's Barrel？

The inner surface hardness of the barrel is higher than that of the screw, and its damage occurs later than that of the screw. In the Blown Film Machine, the scrapping of the barrel is typically due to the increase in the inner diameter caused by time wear. Its repair methods are as follows:

1. lf there is a certain nitriding layer in the cylinder with increased inner diameter dueto wear, the inner hole of the cylinder can be directly bored and ground to a newdiameter, and then a new screw can be prepared according to this diameter.2. Generally, the homogenizing section of the barrel is worn fast, This section (5 ~ 7dlong) can be finished by boring, and then equipped with an alloy steel bushing. Theinner hole diameter refers to the screw diameter, and the normal fit clearance can beleft for processing and preparation.