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A Change of ‘Screenery’


By Mark S. Kuhar

Increasing production and maximizing throughput is nothing new. In fact, next to sizing accuracy a recent survey shows that throughput is the second largest concern amongst producers when surveyed to rank the factors most important when selecting screening media.

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But what happens when external factors such as market growth and adverse weather conditions impact your operations ability to meet the increasing demand and capture your share? Here’s how one producer teamed with his local screening and crushing field specialist.

Over the past 15 years, Yahara Materials located in Waunakee, Wis., has experienced a dramatic increase in demand for clear stone products. These products are widely used for underground pipe and highway bedding to provide proper drainage. The product specifications required clean rock with minimal fines. Yahara Materials needed to find a way to increase their capacity to effectively capture their share of this growing market.

Problem
Yahara Materials operates seven 6 x 20, triple-deck, portable crushing plants that were equipped with slotted, Tri-Lock screens. These slotted screens became very problematic when faced with ever-changing soil conditions found at various locations due to increased moisture content present during the winter and spring months. They were unable to remove enough fines to get the product within specification. The slotted screens would blind over, halting production and minimizing throughput.

Upon the recommendation of Rod Skindrud, the local Unified Screening & Crushing Co. field service representative, Yahara Materials changed to a stainless steel W-style screen on the lower two decks, while the top deck remained a hard drawn, high carbon – square opening, Unified screen for cost efficiency.

This change greatly increased the flexibility of the screen and increased product flow. The W-style screen is composed of straight tension wires, “W” shaped wires and custom cross wires. Three different wire sizes are used for a harmonic screening effect and allows for a greater open area. In addition, the “W” slots perform well during wet and difficult screening conditions.
Solution
“Blinding and sizing problems can be eliminated,” said Nick Cady, superintendent of operations at Yahara Materials. “We have experienced a 15 percent increase to production since the change out to the ‘W’ slots and the W-slot screens are lasting longer. They are lasting two to three times longer than anything we used in this application, in the past.

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“The increase has allowed us to increase our capacity to capture our share of the growing demand for clear stone,” Cady said. “Plus these clean screens have saved us an
investment in a new wash plant for our concrete applications. Our production is up, throughput improved, especially in wet conditions, and we’ve saved an additional step in
processing materials. It was a win-win decision.”

Yahara Materials now uses W-slotted screens on the bottom two decks of all their 6 x 20, triple-deck plants. And according to Cady, “We have not had to change them out all season.”

The primary benefit is the significant reduction in downtime and maintenance allowing Yahara to increase production to meet growing demand. It is just one more example of how the right screening and crushing
approach can make a positive difference.

For more than 140 years, Unified Screening & Crushing has stuck to the principle of giving customers what they want and more. What began as a family-owned wooden fencing business in St. Paul, Minn., is now a leading group of screening, sizing and crushing media manufacturers across the United States. Unified’s history dates back to 1869. The company then produced wood and wood turnings, eventually wire fencing and stair railings, and established the practice of manufacturing products according to customer need. Around 1893, the Toensing family purchased the business and changed the name to Minnesota Fence & Wire Works. By 1911, security mesh and machine guards had been added to the product mix, along with chain link fences, expanded steel railings and steel stairway products. In 1923, sand and gravel screening products were added and the company was on-course to become Unified Screening & Crushing. Today, steel wire tops the materials list, along with urethane, rubber and manganese wear parts. Unified Screening & Crushing Co., www.unifiedscreening.com