March 1, 2010
Getting Wear-Resistance Right: Reality vs. Myth
Extending equipment life with the right wear materials is imperative. And today, getting wear-resistance right requires careful analysis, trusted consultation, and an ability to separate reality from myth. Consider that abrasion-resistance technologies have advanced significantly, yet much myth remains regarding customized wear solutions versus cookie-cutter conventional alternatives. The bottom line is that wear materials must be targeted to each specific piece of equipment and each application, while delivering the desired results cost effectively. The choice isn’t always easy. With that said, let’s take a look at several realities of wear resistance.
#1: Harder materials do not always wear better than softer materials.
“It’s a misconception that materials such as steel, polyurethane, tungsten carbide, and ceramics will always wear better than softer materials such as natural rubbers, which provide energy absorption and will better withstand impact and sliding abrasion,” says Andrew Philp, vice president of sales, Linatex. He explains that raw natural rubber, when vulcanized, delivers greater strength, resilience, and resistance to abrasion. For example, manufacturing technology can retain the long molecular rubber chains inherent in natural rubber, and this helps ensure energy absorption and maximum wear performance. “Conventional rubber products access dry processing, which is based on shearing the rubber during mixing. This leads to a significant drop-off in performance,” Philp says, likening conventional processing to cutting up a good coil of elastic string. “If it’s cut in 10 spots, the elastic will sit very flat and will not absorb the energy of any impact,” he says.
#2: As rubber wear-resistance products vary greatly, work closely with an expert supplier.
For many, it’s difficult to distinguish between synthetic and natural rubber, or between all the products within a range of natural rubber compounds — hence the extreme importance of close consultation with an expert supplier who collects and examines all the required data for a given application.
For example, superior rubber products comprise premium pre-cured or uncured natural rubbers, carbon black and/or silica reinforcements, and numerous compound bases such as nitrile, Bromo Butyl, and neoprene. “The supplier may recommend customized formulations, which means that compositions can be enhanced by adding or removing specific fillers or chemicals, which will then deliver the optimal wear in a specific application,” Philp says. “Also, entire wear systems can be custom-engineered with varying specifications, such as a higher-durometer rubber in a high-impact zone and a lower-durometer rubber in a zone where sliding abrasion may occur,” he adds.
Remember, superior wear resistance technology is not an off-the-shelf, one-size-fits-all approach. Products should be specifically designed for each application, from wet or dry, highly abrasive, or heavy duty and high impact — and for each piece of equipment, from feeders, screens, chutes, and conveyors to pumps, valves, classifiers, clarifiers, cyclones, and more.
#3: Look at the lowest cost of ownership, not the lowest price.
Amid a number of bids, producers often choose the lowest price option, but Philp stresses that you get what you pay for. Although initial upfront costs of the right wear-resistance products may be higher, their superior performance results in a lower cost of ownership. Philp cites an example: A hydrocyclone lined with 10 millimeter premium quality natural rubber delivers an 80-percent savings by maximizing equipment service life between changeouts; dropping the cost of ownership to 20 percent of that of equipment lined with conventional rubber. “The right wear materials will pay for themselves over and over again,” he says.
When examining new field-proven wear-resistance technologies versus conventional choices, those who merely cling to “what has always been done in the past,” may arguably see lesser results. Those who choose the optimum wear materials for a given application will likely reap the returns — and that is indeed a reality of wear resistance.
— Information supplied by Linatex.
Hydraulic pumps increase efficiency
Featuring high-quality, abrasion-resistant compounds, easy serviceability, and an interchangeable design, the Linatex G4 pump range includes both rubber and hard metal pumps. The G4 rubber pump is specifically designed for use in abrasive slurry and chemical applications, while the G4 hard metal pump is engineered for coarse particle size and high-head applications. Each features hydraulic designs which reduce internal turbulence and minimize power draw for greater efficiency — and each offers reduced downtime via easy access to all internal parts and components. Plus, all wear components are manufactured from natural Linatex premium rubber.
Flow control for abrasive environments
Unlike conventional valves, Linatex valve products feature Linatex premium rubber liners for maximum wear life in abrasive flow applications. Designed and customized to meet the demands of tough minerals processing applications, the Linatex valve range offers a choice of heavy-duty steel operating mechanisms and robust steel, iron, or aluminum bodies. Ideal for flow control in grinding and milling circuits, isolation and control in hydrocyclones and separation equipment, slurry and chemical additive control, and a number of specialized process applications, Linatex valve products can be supplied with complete automation packages.
Solves blinding, pegging, and clogging problems
Flex-Mat 3 screen media from Major Wire Industries Limited features vibrating wires that increase product throughput by up to 40 percent over traditional woven wire or polyurethane panels by eliminating blinding, pegging, and clogging. Because there are no cross wires with high-wear spots, wear life exceeds that of woven wire by up to three times. The screen media also has up to 30 percent more open area than woven wire for increased material throughput. Properly sized and installed, Flex-Mat 3 puts more spec product on the ground due to less downtime for cleaning or replacing screens, providing a greater return on investment.
Eagle Iron Works
Wear shoes offer guaranteed fit
Eagle Iron Works provides lifetime wear parts for both its new and previously owned machines. Wear shoes are cast with heavy-duty, long-lasting Ni-Hard iron at the factory, which ensures quality control. If preferred, premium polyurethane shoes are also available. Eagle Iron Works shoes are guaranteed to properly fit its equipment, and its wear parts are said to offer unmatched longevity, resistance, and value.
Specialized and custom wear parts
Excel not only manufactures original equipment, but also specialized replacement parts. The company offers multiple options for replacement components, including a variety of alloys. Examples include spider bushings, socket liners, and main shaft sleeves. Excel can also make application-specific designs for wear parts including an array of feed plates and feed distributors for many cone crushers; offers countershaft boxes made from steel; and performs contact testing on its pinion and gear drives to ensure they are perfectly in sync. Main frames, bowls, adjustment rings, and parts for vintage crusher models are also available.
Designed for maximum efficiency
Stedman offers a primary horizontal shaft impactor rotor that is contoured and computer designed for maximum efficiency for various applications. A proven-positive breaker bar holding device with buried wedges minimizes wear and breaker bar installation, removal, and indexing time. The solid rotor weldment is stress-relieved, balanced, and magnetic particle tested. Interchangeable breaker bars are available in manganese, alloy steel, and hi-chrome. Stedman also offers horizontal shaft impactor rotor rebuilds, including rotors for other manufacturers. Open disk secondary rotors are also available from Stedman.
Wear parts can be Blanchard ground
Dews Foundry castings include gray iron and high-chrome iron produced from chemically bonded sand bolds. Castings can be furnished as rough cast, rough machined, fully machined, heat treated, and painted. The company specializes in blow bars, HSI liners, impellers, anvils, feed discs, flights, paddles, tips, as well as edge and table liners. Parts can be Blanchard ground for a registered fit.