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AGRICULTURE
UHMW-PE: From the Fields to the Grain Elevator
by Roechling Industrial North America

Ultra-high molecular weight polyethylene (UHMW-PE) can extend equipment life and improve operational efficiency in agricultural applications. It has outstanding toughness, resistance to abrasion, low friction, self-lubricating characteristics, chemical and moisture resistance and sound deadening properties. It is cost effective, easily machined and may be thermoformed into two-dimensional shapes and contours such as spouts, chutes, trough liners, complex shaped wear plates and shrouds.

Virgin and reprocessed grades are common for applications where there is limited exposure to the sun. For demanding UV exposure applications, UHMW-PE is available with a UV inhibitor, which extends product life. UHMW-PE is also available in anti-static grades.

As farmers prepare their fields for planting, UHMW-PE provides solutions to wear, corrosion and sticking problems in tilling equipment such as plows, discs and cultivators. Soils can stick to plow bottoms and tillers. Moldboard covers made from UHMW-PE eliminate the sticking because of the material’s low friction, permitting the plow to be pulled through the same soil with less horsepower. They also outlast metal. The results are lower fuel consumption and lower maintenance costs. The use of UHMW-PE as blade scrapers prevent mud from clinging, which reduces drag and resistance, reducing horsepower requirements.

UHMW-PE’s low friction characteristics and abrasion resistance helps to extend chain life and reduce chain replacement time in applications like chain guards and tensioners found in planting equipment such as seed box drills. Replacing metal row cleaners in planting equipment with ones made from UHMW-PE allows for planting in wetter conditions than is possible with metal, since its low friction reduces mud and debris build-up. This reduction in build-up also results in better productivity, since the planters don’t have to be stopped to clear mud. UHMW-PE also provides longer life because of its superior resistance to abrasion, non-corrosive attributes and resistance to chemicals and fertilizer.

With its abrasion and impact resistance and low friction, UHMW-PE is used in combine cutting platform skid plate covers, protecting the steel skid plate from abrasive wear while reducing the drag from the terrain and eliminating the caking of soil. Since UHMW-PE offers better wear resistance than steel, equipment life is significantly improved. The low friction, abrasion resistant covers allow the cutting heads to ride directly on the ground, which optimizes the harvest.

In the combine, steel augers are used to convey grain. Grain’s abrasive characteristics wear the flights of the auger. UHMW-PE, with its superior abrasion resistance, is used as auger flight facings to extend the life of the auger. It is also used as auger liners in combine head troughs and grain tanks. Its resistance to corrosion and wear ensure long life, while the low friction properties promote faster grain feeding. The UHMW-PE liners can be used to cover steel that is already rusted and corroded, even if holes are present.

Other combine applications include clean outdoors and feed plate covers, where UHMW-PE outlasts steel by 2:1, while improving grain flow. Feeder throat linings, rail covers and sprocket stripper plates made from UHMW-PE reduce noise by eliminating metal-on-metal contact, while offering corrosion resistance, improved material flow and extended life. UHMW-PE tire guards prevent stubble from puncturing combine tires. UHMW-PE is also found in bearing, bushings and other component applications because of its low friction and self-lubricating properties, also eliminating metal-on-metal contact.

At the grain elevator, bucket elevators lift the grain to a distributor where it flows by gravity through spouts or conveyors to bins or silos. Bucket elevators have shaft dust seals made from UHMW-PE, where low friction and abrasion resistance are integral properties. Steel spouts, which are lined with formed UHMW-PE to take advantage of its low friction and wear characteristics, are used in moving the grain to storage silos. Grain is also distributed by grain pumps and drag conveyors that feature paddles made from UHMW-PE. In these applications, the low friction, abrasion resistant paddles prevent metal-to-metal contact, ensuring longer chain and conveyor life and lower horsepower requirements. They efficiently transport large quantities of grain with reduced product damage.

When the bins and silos are emptied, grain is sent by auger, spouts or conveyors to trucks, rail cars or barges where it is sent to mills, ethanol plants or other food processors. These applications also feature UHMW-PE for auger flight facings, liners or paddles. Spouts can be made solely from UHMW-PE for easy handling, since its weight is one-third that of steel.

Whether UHMW-PE is used to make a component in original farm equipment or used in after-market applications, it is a valuable contributor in improving the productivity of farm operations while enhancing the life of wear parts in the grain industry.