Plastics, abrasion/erosion resistance

Abrasion/erosion resistance - Plastics are routinely compoimded for good wear resistanee. 

Some aspects of plastic wear are hardly even discussed in manufacturer s literature plastic abrasivity, plastic abrasion resistance, and plastic erosion resistance. The manufacture of many plastic products involves the use of injection molding or extrusion equipment. If a plastic contains inorganic fillers such as glass or carbon fiber reinforcement, they can be veiy abrasive to parts that contact the melted plastic extruder barrels, screws, molds, and check valves. 

Plastics are often used for abrasion and erosion resistance, but like abrasivity, there are no agreed-to tests to rate materials for ftiese types of applications. 

Wear is the removal of surface material by one of three mechanisms erosion, abrasion, or cavitation. Erosion is the removal of a polymer s surface by abrasive materials carried in a fluid medium. We see this type of wear in plastic pipes used to transport waterborne slurries of minerals in mining operations and in vacuum transfer pipes used to convey powders in a stream of air. Abrasion is the result of two surfaces sliding against each other. We commonly observe abrasion of polymers in the fabrics of our clothes and upholstery. Cavitative wear is caused by voids in a liquid medium collapsing against a surface. It is essentially an impact process. Cavitation is a relatively uncommon cause of wear in polymers. Pump impellers are one of the few applications where polymers must resist this type of wear. 

An alternative to rubber linings which suit corrosive environments are glass flake reinforced plastics. They combine impact, erosion and abrasion resistance and can be applied on site using a spray or brush. They are compounds of glass flakes with various corrosion resistant thermosetting resins combined in different ratios. The excellent adhesion enables bonding with steel at temperatures as high as 170 "C. 

Plastics and elastomers are frequently used for wheels for a variety of consumer products. Everything from in-line skates to barbecue grills, to strollers, use plastic wheels. How do various plastics resist abrasion from contact with concrete pavement Erosion of plastics is a factor in dishwashers, plumbing systems, fans, and pumps. Most domestic sump pumps are now made from plastics and in use they are required to carry sand-filled water from basement drain crocks. How do various plastics resist this type of wear ... 

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