Full Encapsulation of Feedscrews
Extreme Coatings' Full Encapsulation option provides the ultimate in abrasion and corrosion resistance for single and twin feedscrews. This option covers the tops of flights, flight sides and the root/core of the entire feedscrew.
The low heat input during our coating process (350F, 175C) ensures no distortion and minimizes costly straightening or machining requirements. Our coatings are routinely applied over standard hard facing alloys.
Our standard coating thicknesses are .005” (.125 mm) for screws of diameter 36 mm and below and .010” (.25 mm) for larger feedscrews. Diamond polishing after coating provides a super 6-10 RMS (uinch) (.2-.4 Ra Umeter) mirror surface finish. This surface finish aids in purging and reduces the tendency for material to build up.
Full encapsulation is recommended when processing fiberglass, calcium carbonate, titanium dioxide, metals, ceramic or other abrasive fillers.
The porosity of our finished coating layer is very low, less than 1 percent. This low porosity and the inert nature of the coating materials provides a very corrosion resistant surface. For hard to process materials such as fluoropolymers and CPVC, carbide coating provides a less expensive alternative to high nickel alloy steels.
Remember, we guarantee at least double the life of any carbide encapsulated feedscrew.
Cut-away Feedscrew showing our coating layer uniformity