Stone, sand and gravel can take their toll on material handling equipment for concrete production. The bare structure of transfer or storage components and vessels may not adequately resist wear, and even traditional steel or rubber protective liners can prove insufficient to withstand abrasion.
Sheets made from urethane provide far better protection than more traditional options such as rubber and AR400 or AR450 plate steel for such applications, according to Argonics Inc., one of the largest North American wear-resistant urethane producers. Urethanes are cost-effective, dependable elastomers that combine some of the performance advantages of high-tech metals, ceramics, and plastics, along with the resiliency of rubber. Because they also offer significantly less friction than rubber, they help to reduce wear when in contact with rough materials like aggregate, and prove easy to clean.
This “tougher than steel” grade of liner can now be made even more durable with embedded ceramic tiles, Argonics notes. It can also be cut from full sheets of various sizes to fit the contours and shapes of high contact areas, so it can easily be welded or bolted to provide extreme wear protection wherever required. While such liners can be cut to fit and installed onsite, custom liners made to fit more complex configurations can increase reliability, simplify installation, and further reduce production downtime.
Extreme Wear Resistance
Urethane elastomers’ abrasion resistance has led to many key concrete and aggregate plant applications. “In plants that handle bulk materials, where severe wear is a problem, special urethane formulations like Kryptane can last several times longer than steel or rubber, which reduces production downtime, replacement cost, and labor for change out,” says Argonics Industry Product Specialist Jesse Roberge.
|The extreme wear resistance of standard or ceramic tile-embedded urethane liners—shown here on a bin, drum and conveyor turnhead—can offer plant operators, design engineers and equipment manufacturers extended equipment life and trouble-free handling of sand, gravel and stone.|
Compared to steel liners, urethane significantly reduces the noise level of material handling and transfer, he adds, noting, “When aggregate falls onto metal, it can be quite loud, particularly if it is in an enclosed building. Because the urethane has natural resilience, it deadens the sound quite a bit and makes conversation easier.”
Kryptane, an extremely wear-resistant material the company formulated for conditions where abrasion, sliding, or impact occur regularly, is often used for drum, chute, bin, hopper, and conveyor liners. Different applications require different thicknesses of urethane. “For an aggregate batcher or bin/hopper, we recommend a ½- to ¾-in. thick liner, which can last five to 10 years,” says Roberge. “In fact, some wear liner manufacturers offer a warranty of several years or based on the yardage put through a drum.”
To most effectively control extreme wear, such as for feed chutes, discharge chutes, and turnheads, he recommends the use of liners that actually embed ceramics into the urethane: “[They] can be optimized to resist not only sliding abrasion, but also impact, or various combinations of the two. This approach can last up to 10 times longer than steel or rubber alone, and up to four times longer than urethane alone.”
To resist liner degradation in hot, humid climates and further extend liner life, Roberge also advises the use of an ether versus a typical ester urethane formulation.
Concrete plant staff can cut and install wear liners on their own using weld-in or bolt-in methods. Standard Argonics urethane sheet sizes are 4- x 8- or 10-ft. and 5- x 8- or 10-ft., in 3/16 in. to 1 in. thicknesses. Urethane or embedded-tile urethane rolls are available in 4 x 25 ft. or 5 x 100 ft. sizes, or 12- x 12- or 18-ft. modular panels—all in a variety of thicknesses. The materials can be quickly welded or bolted in to manage certain common “hot spot” conditions.
Bulk material handling equipment manufacturers and users turn to custom liners in instances where standard sheets do not fit, size or weight is a concern, or a long-term wear solution is required. “When custom liners are cut to an exact size or pre-molded to fit right into the equipment, it eliminates wasted material and the need to cut and trim onsite,” says Roberge. “Because such pieces are manufactured to fit precisely together, they install quickly with minimal production downtime. They are also easy to replace a piece at a time as needed.”
The customer typically provides a sketch, drawing, or photo of the bulk handling equipment to be lined, along with dimensions and notes, he adds. The wear liner fabricator then finishes the drawings and provides a quote. — Argonics Inc., Gwinn, Mich., 800/991-2746; www.argonics.com