Unique Challenges Require Creative Solutions

Recently, we ran across a customer who was in dire need of replacing their existing slider bed belt conveyor. This conveyor carried a continuous flow of molten plastic out of a 400°F oven, up an incline and into an extruder. The trouble the customer was having included belt stretch and the product leaving residue on the belt, which in turn transferred onto the pullies, return rollers, and anything else it in which it came in contact. Once the pullies and rollers accumulated product, belt tracking became difficult.

There were also issues with the product sticking so the customer had to scrape the product to get it to release from the belt surface. Numerous belts had been tried over the years, and none of these fixes worked well for the customer. They ended up using water on the hi-temp belt surface, which helped with the product release, but wreaked havoc on the painted steel conveyor.

Exploring the Characteristics of a Stainless Steel Belt

When talking with the customer, a steel belt came up in the discussion. A steel belt seemed like a good fit with the high temperatures and smooth conveying surface, but we were not sure how or if the product would release, or if there would be enough friction between the belt and the product to travel up the incline. While we had heard of this type conveyor, we had not run into an application for it before. We discovered that it is generally similar to a standard PVC/polyester carcass belt conveyor other than the fact that it was endless, with a welded seam and completely smooth.

In talking to the manufacturer, we discovered the steel belts were typically made of stainless steel, but also available in a variety of alloys for many applications such as food processing, robotics, medical device manufacturing, and automated assembly lines, among others. Regarding belt tracking, we will be using a V-guide with the high-temp rated adhesive to glue them to the bottom side of the belt.

As you can imagine with a steel belt that is .020” thick, the pullies at each end needed to be larger than for your typical belt conveyor. This belt required pullies that were each 12-1/2” in diameter and 3” wide. We’ll have two of these pullies at each end for our 10” wide belt conveyor.

Testing Possible Options – Plain or Teflon Coated?

The belts that we are investigating for our application are either the plain stainless steel belt, or the stainless steel belt with a Teflon coating applied. We have a sample of each that the customer is now testing. In this application, we need the product to convey up an incline, yet still provide a clean release at the discharge end of the conveyor. We may still need to provide a “scraper” to help with this release, but we feel that this can be accomplished using a scraper made of nylon, UHMW, or another non-stick non-marking product, as the scraper could remove a Teflon coating from the belt surface.

Other Considerations

The extreme heat of the area that this conveyor will be installed required us to use a stainless steel frame, which added to the cost. The original version that we quoted utilized an extruded aluminum frame.

If you ever have an extreme temperature or otherwise hostile environment where a smooth belt may be a requirement, take a look at a steel belt!

While every operation is different, some have unique challenges that require creative solutions. If you’re struggling with unique challenges in your facility, contact us. We’re happy to help design a creative, effective solution that will improve performance for your operations.

Author: Tom Gregovich