The Problem:

A manufacturer of extrusion equipment approached Extreme Coatings for help to solve a high wear issue with one of its customers. This proprietary process coats paper with a thin, uniform film of highly filled (iron ferrite) polymer. This film is later magnetized to create a printable paper with a magnetic backing.

Line speed is critical to quality film deposition and this dictates when a screw and barrel system is out of tolerance. When an uneconomic rate results the feed screw is removed and rebuilt. A 2-1/2” extrusion screw with C83 hard facing and chrome plating lasts about 70 days in operation. Total production at this point is about 150,000 Kg of material processed.

The Solution:

Extreme Coatings applied their XC9000 Millennium carbide which is designed to combat fine particle abrasion. The screw is 2-1/2” (63 mm) with barrier flight and mixer. Coating thickness was .010” (0,125 mm) with a mirror 16/32 (0,4- 0,8 Ra) finish. This screw was installed in July of 2005.

The coated screw processed for a total of 210 days until output rate became uneconomical. Total wear in the barrier/compression section of the screw was 0.28” (0,7 mm) and the screw was stripped of remaining tungsten carbide to be rebuilt and recoated with XC9000.

Benefits:

The customer was very pleased with triple the wear life of their previous screw. Most importantly, total output for the coated screw was 675,000 Kg of material, a 25% increase over the previous feed screw. (See graph) By maintaining a close tolerance between the screw and barrel, this extrusion system operated more efficiently for a longer period of time resulting in higher total outputs.