Canoe liners boost throughput for sand-and-gravel producer

By |  June 3, 2016

Fisher Industries is ranked as one of the top 25 sand-and-gravel-producing companies in the United States, and it has earned that spot over more than 60 years of growth. Starting as a small aggregates operation in North Dakota, the business today is comprised of eight companies operating in nine western states, with a team of 1,100 employees.

Getting the tough jobs done right requires monitoring every production detail. So, when Fisher Industries’ managers noticed its aggregates business was replacing conveyor skirt-board and flashing too often, the company jumped on the problem. More frequent replacements meant more plant downtime – and the downtime was costing Fisher Industries money.

The company had been using skirt-board rubber (also called flashing rubber) for liners and wear parts along the sides of conveyor belts, underneath screens and crushers and in other hard-to-reach places at its screening and crushing plants.

Fisher Industries replaced skirt-board rubber on many of its conveyors with Unified canoe liners.

Fisher Industries replaced skirt-board rubber on many of its conveyors with Unified canoe liners.

The skirt-board rubber was 1/2 in. thick with no backing. Under production conditions, abrasive aggregates would wear a hole in a skirt-board liner, which would then break and require a plant shutdown for replacement. These blowouts happened frequently and took a toll on output.

Curt Kittelson, a Fisher Industries general manager, says the company purchased skirt-board rubber in rolls 5 to 8 in. wide and 50 ft. long. Installation involved cutting the rubber to size and punching holes in it for bolt-in positioning or by clamping it in with clamping bars.

“The increased time for replacement became unacceptable,” Kittelson says, “with shutdowns, dismantling of the broken skirt-board rubber and even safety concerns. Sometimes, broken skirt-board rubber had to be replaced inside a machine, in locations not easy for a person to get to. It was always a difficult repair or changeout,” he says. “Many times after plant restart, the skirt-board rubber would leak material, resulting in more maintenance.”

Alternative

After site inspections and discussions with Kittelson’s team, Dean Klocow, a service representative for Unified Screening & Crushing, recommended that Fisher Industries replace all worn skirt-board rubber with Unified canoe liners. They’re modular units made of 65-durometer rubber that’s molded to a steel backing plate. And they’re designed to be easily adjustable.

“We engineer the Unified canoe liners and impact pads for use under crushers, chutes, hoppers, bins or at the feed end and sides of conveyors to absorb the high impact of heavy loads,” Klocow says. “Impact pads are basically designed and manufactured, just like canoe liners, with the same steel-backed rubber.”

The company provided Fisher Industries with impact pads in custom sizes from 12-in. x 12-in. up to 24-in. x 24-in., and custom canoe liners measuring 1 in. thick x 6 and 7 in. high in 6- to 8-ft. lengths.

Kittelson says this alternative solution was cost effective in high-impact and high-abrasion applications.

This photo shows a belt feeder with canoe liners after six months of wear.

This photo shows a belt feeder with canoe liners after six months of wear.

“We discovered they outlast plain mild steel and abrasion-resistant steel plate,” he says. “The liners’ wear life is substantially better than skirt-board rubber and they mostly sealed the material from leaking.”

Kittelson adds that installing the product is easier than wrestling with the skirt-board rubber.

“It’s still a two-man job, but once setup is done – putting in a metal strip that the liners bolt to – it goes very quickly,” he says. Adjusting the canoe liners takes just a simple tap-down, rather than a re-bolting process.

Fisher Industries conducted various field tests of the canoe liners over an extended time, running all types of material – limestone, granite, quartzite and more.

“In our operations, high-impact areas vary all the time,” says Delmar Meier, Fisher Industries’ shop supervisor. “We may run sand and then granite on the same portable plant, one after the other. The Unified canoe liners do very well in the applications they were designed for: high-impact and high-abrasion.

“Running sand, they do about the same as the skirt-board rubber. But an advantage of the canoe liners is the slots that make it much easier to adjust the height of the liner just above the conveyor. That gives us some control over any material leakage.”

Community and education

This Alamo, N.D., site is in the state Fisher Industries got its start. In 1998, the company expanded operations to the southwestern United States.

This Alamo, N.D., site is in the state Fisher Industries got its start. In 1998, the company expanded operations to the southwestern United States.

In addition to the high volume of production that has made Fisher Industries one of the largest producers in the country, the company also takes pride in the communities in which it operates, providing annual donations to charitable organizations and sponsorships of local clubs and sports teams. These include:

  • Boy & Girl Scouts of America
  • 4-H
  • March of Dimes
  • United Way
  • Relay for Life
  • Walk to End Alzheimer’s

Residents of Dickinson, N.D., and its surrounding communities have enjoyed the addition of the Henry Biesiot Activity Center, whose football field has been aptly christened “Fisher Field” thanks to the substantial donation made by Fisher Industries. The activity center is used by the athletic programs of Dickinson State University, as well as Dickinson’s public and Catholic schools.

Fisher Industries also actively supports the educational advancement of area youth and adults, sponsoring an annual scholarship for employees or children of employees who are attending Dickinson State University.

Information for this article courtesy of Unified Screening & Crushing.


Company history

It all began on the vast prairies of southwestern North Dakota more than 60 years ago. It was there that Fisher Sand & Gravel was born. Through the vision and leadership of company founder Gene Fisher, what began as a small but enterprising aggregate-processing company quickly emerged as a leader in portable crushing operations. Today, Fisher Sand & Gravel Co. is ranked as one of the top 25 sand-and-gravel-producing companies in the United States.

By 1967, Gene Fisher recognized the need for durable, customized equipment. Thus, he launched General Steel & Supply Co. to design, fabricate, repair and remodel aggregate-processing equipment. Today, General Steel operates two well-equipped metal fabrication facilities, and the company’s customized equipment is sold to countless businesses throughout North America and abroad.

In 1998, Fisher Industries’ President Tommy Fisher expanded operations to Arizona and the southwestern United States. The Fisher Industries portfolio currently includes concrete, asphalt, drilling, blasting and paving services, along with the sale of various aggregate products. But the company says its foundation has been, and will always be, mining aggregate materials.

Allison Barwacz

About the Author:

Allison Barwacz is the digital media manager for North Coast Media (NCM). She completed her undergraduate degree at Ohio University where she received a Bachelor of Science in magazine journalism from the E.W. Scripps School of Journalism. She works across a number of digital platforms, which include creating e-newsletters, writing articles and posting across social media sites. She also creates content for NCM's Portable Plants magazine, GPS World magazine and Geospatial Solutions. Her understanding of the ever-changing digital media world allows her to quickly grasp what a target audience desires and create content that is appealing and relevant for any client across any platform.

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