Out of all the plastics used in sawmills polyurethane is the most versatile. The material is available from “eraser soft” to “bowling ball” hard and permits a use in a very wide range of applications. A quick overview of the different types of Redco polyurethanes and potential applications:
Redco Deadplate: at 52A this is our softest urethane and is specifically used as a shock-deadener. This is used wherever logs/lumber impact part of the mill and serves to reduce or eliminate wear and damage from impact. Deadplate is commonly sold bonded in a sandwich between two pieces of steel.
Redco 54A: A urethane that has excellent gripping characteristics, it is often used as tires for Redco carry-over wheels.
Redco 6060: Primarily used in applications where impingement is a concern and has limited applications so far in sawmills.
Redco 70A: Can hold heavy load and has high compression resistance. Primarily used as shock and vibration pads.
Redco 80A: Provides a compromise of pliability of the softer urethanes combined with with the high shock, load and vibration tolerances of the harder urethanes. Also used as a carry-over wheel tire material and is excellent in scraping applications.
Redco 430: Perhaps the most well-balanced urethane of all, Redco 430 provides excellent shock, vibration, impact and impingement resistance. At 90A on the hardness scale it straddles the line between rubbers and “plastic” hardness. Used as bumpers, shock/vibration pads, deflector plates.
Redco 500: A slightly harder polyurethane than Redco 430, it has high abrasion and impact resistance. Used in shock, impact and isolation pads and liners and also as wear plate.
Redco 600: Used in applications where deformation of the urethane is a problem and also performs very well in cold weather applications.
Redco 750 and 750 SXL: Bearing-grade polyurethane. Very common in sawmill applications in all sorts of hanger bearings, bushings, sprockets, lugs, bearing inserts and much more. The SXL version is lubricated for dry-running periods.
Redco SPS-2000: Also 75D hardness (same as Redco 750) this is a PULP-SAFE polyurethane designed for kraft pulp applications. It dissolves in the cooking process and makes contamination impossible. Is a substitute wherever Redco 750 would otherwise be suitable.
Why use polyurethane in your sawmill or planar mill? Urethanes bring many useful characteristics to the job:
-Oil, grease and chemical resistance
-Controllable rebound
-Heat, water and low temperature resistance
-Mold, mildew and fungus resistance
-Machinability