Coefficient of Friction (CoF) is a significant and constant problem in the world of flexible packaging. The processing of plastic film causes various conditions on the surface of the product which can often interfere with the flow of the film through machines and equipment.
The problem of CoF is one that needs to be addressed by film manufacturers and converters every day, and maybe the best way to do so is through the use of additives during the manufacturing of the film.
“One of the main aspects of our business in the films we make for converters, is controlling the Coefficient of Friction, which has a lot to do with the charge that plastic films tend to like to hold onto,” says Randy Scott, vice president of global marketing for Pliant Corp.
“If the film is left untreated, you get film that is too attractive. It doesn’t want to flow properly through equipment; it doesn’t bond properly, etc. The whole reason we’re in business, in a lot of cases, is to develop film solutions that incorporate certain additives that help to minimize that impact.”
Pliant had dealt with this type of problem for years with regard to its sealant web in a variety of ways, as the company would customize solutions based on a given customer’s needs and applications.
“One customer may laminate our sealant web to a different material than another customer, so we have to account for that. Their customer may be running a different type of filling equipment (horizontal f-f-s vs. vertical), so we account for that. There may be issues with laminations; the film may run fine as a stand-alone film but if run as a lamination there may be bonding problems or issues with ink retention,” says Scott.
“We’ve got dozens if not hundreds of different formulas, and sometimes a number of different products for a given customer – depending on what they’re doing. But quite often it’s hit or miss. You can’t account for everything,” he says.
Pliant’s mission statement with regard to this challenge was to find the best way to control CoF so that a direct user, and ultimately the end-user, receives a good product that works consistently, yields maximum output and minimizes problems like line stoppages.
The company’s goal was further complicated when considering environmental concerns such as humidity (especially in summer vs. winter and how that impacts the surface) and the age of the product, which can cause major problems. Pliant’s film may test perfectly when it’s “fresh,” but after sitting in a warehousing environment for a few weeks, months, etc. it may not have the same capabilities.
Creating a Standard“We clearly saw an unmet need in the marketplace for something that was more consistent and less reliant in a given set of environmental circumstances, where we could come out with something more ‘standard’ for the marketplace,” says Scott.
Whereas, the traditional additive utilizes a slip agent called an erucamide used to varying degrees, Pliant worked with one of its key partners to develop a non-erucamide proprietary system.
The system (including a family of films featuring the new additive) was launched in late 2007 after much internal work by Pliant and its vendor partner, and based on the positive feedback, the company is now ready to introduce it to the marketplace.
Called the GlideFast family of films, Pliant is excited about this new product and the early returns point to great results.
“We thought GlideFast was a good name because at the end of the day, it’s all about throughput,” says Scott. “We think that customers, after they use it for a while, they’ll feel it just glides over their lines and runs very fast. Based on the data we’ve seen, we think it’s going to really overcome a lot of the variables that we’ve had to contend with.
What we’ve seen so far is that GlideFast significantly reduces the impact of aging and the impact of different types of filling equipment. Some customers may have to tweak some of their adhesives systems, because they’ve never seen anything like this before, but most have had zero problems. It’s a drop-in system and people are already seeing the advantages.”