One way that some flexible packaging operations often try to save money is using single-layer films or low-cost multi-layer films in their vertical form fill seal (VFFS) machines. The thought is that by reducing the costs of materials, like films, used at the beginning of production, the savings will compound as the process moves along. In essence, this strategy attempts to build cost savings into different stages of the process lifecycle so that the end result is greater profitability.
This approach may look good on paper, and may even make sense in many situations, but in many cases, it ends up being shortsighted as complications from the cheaper (usually lower quality) films begin to crop up down the line. The resulting losses in product, productivity and customer satisfaction caused by the failure of the cheap films far outweigh any short-term gains made in profitability during procurement.
At the end of the day, a bag is only as good as the film it is made from, and like most things, you get what you pay for.
There are evolving demands of flexible packaging applications, and the advantages of well-engineered coextruded (coex) films are plentiful.
More Demanding Applications
As advances in technology continue to change what’s possible in the marketplace, customers are expecting more from their flexible packaging solutions. Many times, technologies are created in response to customer demands, but in some ways, an “I don’t know what I want until I see it” mentality also exists.
For example, a generation ago, before metallocene catalyst technology revolutionized resins, there was a certain level of expectation for film quality and performance. Now, customers are used to the enhanced performance and cost savings that those resins have produced.
Likewise, in years past, customers may have accepted a higher rate of failure in their packaging solutions – bags that leaked, ripped or didn’t always reliably protect the product – but since improvements in films have become widespread, they are now accustomed to better performance and much less tolerant of package failures.
In addition to higher customer expectations, increasing packaging line speeds are also placing greater demands on the films used in flexible packaging. This is largely because when product fills bags faster (and presumably more forcefully), the films need to be stronger and more flexible to prevent damage from fast-moving VFFS machines. Once the bags are filled, their real work begins.
In today’s flexible packaging industry, longer distribution chains and aggressive cost containment initiatives place enormous pressure on the performance of films. Most products no longer travel from Point A to Point B (producer to retailer or end user). Extended supply and distribution networks now make it more like Point A to Point B to Point C to Point D to Point F, and beyond. Geographical boundaries are all but disregarded.
Although this new distribution model is great for consumers in our on-demand society who crave variety and accessibility, it means that packaging is handled and transported far more often than it used to be. So, to ensure that products survive their multi-stop journeys, packages need to be stronger than ever before to stand up to the rigors of the road.
To complicate things, businesses that are distributing their products farther and faster also want to keep packaging costs down. At times, the desire to save money lures companies down the path of skimping on film quality (chosen for lowest cost), which can result in package failure and unsatisfied customers that negate any initial cost savings.
Advantages of Engineered Coextruded Films
For some flexible packaging applications, engineered coex films are heads above single-layer films, and even three-layer coextruded films. Engineered coex films are great because they can leverage the desirable attributes of different materials to provide flexible packaging professionals “best of all worlds” solutions that successfully blend strength, flexibility and value.
Engineered coextruded films typically offer greater impact strength than single-layer or non-engineered coex films. This keeps the contents of the bag from puncturing through the film, but also helps to protect package contents from ambient hazards that may cause damage. For example, engineered coex films increase dart values by up to 30 percent. Similarly, the tensile strength of these films is dramatically higher, which makes the packages constructed from them highly resistant to tearing. Engineered films can withstand pulling forces of over 5,000 psi.
The differences in modulus values – the stiffness or rigidity – between engineered and single-layer or non-engineered films are very striking, too. With engineered coex films, the modulus value increases by 50 percent or even double. This makes the bags easier for VFFS machines to form and fill. And because the packages are stiffer, line speeds can be increased.
Alongside all of these positive characteristics of engineered coextruded films is a dramatic increase in barrier properties. A bag made from engineered coex film can offer up to 20 times the amount of protection against potentially damaging odors or environmental hazards. For instance, an engineered coex film is an excellent choice for bags that carry perishable items that spoil faster when exposed to oxygen.
Real World, Real Results
A large-scale poultry processor uses a VFFS machines to package fresh chicken that is sold to institutional food distribution clients, and this processor had been using three-layer coex film to bag its chicken, but was finding that it had problems with leaking packaging.
Health concerns and other hygiene issues were leading to refused shipments by distributors with so-called dry warehouse and trucking mandates, and made it imperative that they find an effective solution.
As they began to consider options to combat the leakage problem, they were searching for a cost-effective solution that wouldn’t blow up their budget. After exploring a number of alternatives, they decided that they were most concerned about customer dissatisfaction due to package failures. So, with some trepidation, they went with a nine-layer engineered coex film that was significantly more expensive than their previous three-layer film.
After making the switch, the company immediately noticed a dramatic reduction in the failure of its packages as the leakage rate plummeted by 75 percent. They expected the bags to perform better, but not like this. And, as a silver lining, productivity of its VFFS machines jumped by 15 – 20 percent with the higher quality film. So, despite the added material costs of the new film, their business benefitted through enhanced productivity, fewer product rejections, and better customer satisfaction and retention.
