UHMW Keeps Products Moving
By Peter Daumeyer and Randy Kirkpatrick
Who remembers the television show "Laverne and Shirley," about the two roommates who work in a brewery? The opening scenes show them at the bottling plant, the bottles passing by and, finally, a glove on the beer bottle going down the conveyor.
You can think of the fictional Shotz Brewery as a predecessor to Duff Beer, the fictional brand on "The Simpsons." In those opening scenes, we see the beer bottles traveling down a conveyor on their way to being packaged and shipped around the globe.
Think of the products sitting on your desk right now. Do you have coffee, water or soda nearby? Think about how it was packaged. The product, whether it was coffee grounds, purified water or your favorite carbonated beverage, was handled in a plant somewhere, packaged and delivered nearby for your local purchase.
Let's follow the soda. A local bottling plant produces the product in bulk, then pumps it into 2-liter bottles. Those bottles move at a rapid pace down a conveyor where they are then capped and packaged into a larger container for shipping to the distributor. The distributor then unpacks and repacks in bulk to ship to the local store. As those bottles travel down the conveyor, think of the many plastic parts that keep them moving. The conveyor can be tricky, because 2-liter bottles can be awkward and fall. That's why there are guide rails on the sides of the conveyor to keep the bottles upright and on top of the conveyor. These rails, usually made of ultra high molecular weight polyethylene (UHMW) with a metal back, are clamped along the conveyor edges with metal rods to hold them in place.
The use of UHMW in the bottling/canning and packaging industries has been rapidly expanding in recent years. Not just in total volume, but in the types of applications. During this same time frame, engineered plastics processors and plastic distributors have been diligently working to educate the engineers and maintenance personnel of the bottling/canning and packaging industries on the benefits of using UHMW. This product now plays a major role in keeping the costs of production and maintenance to a minimum, effectively keeping that same 2-liter bottle of soda affordable and enjoyable year after year.
Artek, Inc.'s Duravar rod stock machined into a timing-screw feed system ensures that bottles are perfectly timed for proper filling and don't get jostled while being filled and capped, getting them through the conveyor line without mess.
Advantages of UHMW
The popularity and use of UHMW profiles, shapes and fabricated components continues to grow year after year. The high abrasion resistance, low coefficient of friction, impact strength and chemical resistance properties make UHMW the material of choice to extend equipment life, reduce energy and maintenance costs and improve operation performance.
Another factor making UHMW the product of choice is its excellent acoustic damping properties. With OSHA cracking down on noise in plants, this can be a key benefit for plant personnel. The cost relative to competitive materials, and the fact that it meets FDA specifications, makes UHMW a perfect fit for the modern — and not so modern – bottling and packaging plant.
UHMW can be ram-extruded into profiles and shapes used to solve application problems. The most common profiles in the bottling/canning and packaging equipment industry include: guide rail, chain guides, bar clip-ons, drive bar cap, rail clip-ons, j-legs and the dogbone. Each of these profiles are designed to improve movement, extend wear life and reduce maintenance and clean-up time. In addition to these standard and custom profile shapes, many UHMW components are fabricated/machined from UHMW bar and sheet materials to create timing screws, star wheels, straight and curve track and various bushing and roller configurations.
“High abrasion resistance low coefficient of friction, impact strength and chemical resistance make UHMW the material of choice to extend equipment life, reduce energy and maintenance costs and improve performance.”
UHMW is a perfect fit for any type of food product, with the inability of contaminates to attack the guide rails. This keeps the product clean of disease from part to part. And with the better chemical resistance and higher application temperature of UHMW-PE, the conveyor can be cleaned with a complex bleach and hot water wash down with no fear of degradation.
UHMW has good abrasion and impact characteristics. Think of beer as it is being put into a glass bottle. Say those bottles fall and scrape along the conveyor. No worries, as they will not damage the UHMW. Maybe some product spills on the conveyor. Again, not a problem because the UHMW will stand up to most standard chemicals, even the acidity of a soda and alcohol.
If regulatory compliance is of concern, you can rest assured that UHMW is in compliance with FDA regulations. Check with your material provider, but most UHMW extrusions have USDA approval for direct contact with meat and poultry for food handling applications. So raw meat can be consumed after contact with UHMW. Even some premium UHMW materials meet the 3-A Sanitary Standards.
Duravar ultra-high molecular weight polyethylene (UHMW-PE) from Artek, Inc. serves many important functions in a conveyor application, from the curve track to the guide rail to the j-leg, improving equipment performance and reducing maintenance costs.
So why are we just talking about bottles of soda? Let's look at all of the materials that can be handled with UHMW. Simple consumer goods are a start, but then there are industrial products.
The mineral business counts on UHMW not just for their conveyors, but for the containers in which product is pulled from the mines, put into rail cars or trucks and transported to mills for processing. Most transportation companies will line their vehicles with UHMW to keep the sides from being damaged by heavy ores and stone. The exceptional wear resistance allows the product to beat up the plastic with very little damage, unlike how it would impact the metal sides of vehicles without this protection. The excellent coefficient of friction will allow the product to flow out of the container with very little sticking to the sides or bottom.
Most packaging machines rely heavily on UHMW for the friction resistance as products move from production to packaging and out the door. A typical accumulator will be lined with UHMW so the product will not stick in corners or need to be pushed along to the feed point. Likewise, any brush or guide that slides along the accumulator will do so without any regard to the plastic underneath it. The UHMW will allow the brush to do so with very little friction involved. Thus there is less stress
on the motor, and the motor will last longer.
UHMW is used in the logging industry to keep the wood moving. Once a trunk is loaded into a saw, it travels along a UHMW-lined chute to the saw for trimming into smaller sizes. Often the paddles and blocks are made up of UHMW to continue with the near frictionless idea to keep bits of wood from sticking to the conveyor.
Now with the advent of large shippers such as Amazon, we are looking at cardboard boxes being shipped by the thousands each day. All of these boxes start out as a flat sheet in a warehouse. After the order is entered, the picker sorts the material being shipped and a box machine takes the flat die cut cardboard and glues and folds it into a box. The material is dropped into the box and the box is taped shut. This is just the beginning. Now that box must be fed onto a truck from its location in the warehouse. Usually this involves a conveyor or chute of some kind. Cardboard has a lot of friction, so sending it down a metal chute doesn't make a lot of sense. Thus, the chutes are lined with UHMW to reduce the friction and allow the box to slide freely. Next the box is loaded into a truck for carriage to the shipper.
UHMW Gets it to You
Whether it's the clothes you bought, the soda sitting on your desk, the fertilizer on your lawn or that bottle of Shotz, UHMW was likely involved in the handling process. Think about the factories near you. How are they moving their products throughout their facility? How much automation is speeding up the process – and presenting more friction, more chance for contamination or more chance for damage to equipment? How many of those concerns can be eliminated with ultra high molecular weight polyethylene?
Originally published in the International Association of Plastics Distribution Performance Plastics Magazine, April/May 2019 publication.
Randy Kirkpatrick is the director of sales and marketing for Artek, Inc. For more information, contact Artek, Inc. at 3311 Enterprise Road, Fort Wayne, IN 46808-1398 USA; phone (260) 484-4222 or (800) 762-6808, fax (260) 484-6914, email@example.com or www.artek-inc.com.
Peter Daumeyer is a territory manager for Cartier Wilson LLC and chair of the IAPD Editorial Committee. For more information, contact Cartier Wilson LLC at 34194 Aurora Road, Suite 231, Solon, OH 44139 USA; phone (770) 644-0000, firstname.lastname@example.org or www.cartierwilson.com.