How can we reduce our plastic use without sacrificing load containment performance?
Question from Gil: How can we reduce our plastic use to meet our sustainability initiatives without sacrificing load containment performance?
Hi Gil,
Your question is timely since legislation and corporate objectives are driving today’s sustainability goals, but they do not define how it is to be accomplished (and I don’t have to tell you, that is the hard part). I can answer your question, but first, we need to understand the variables involved in this equation. And yes, it really is a math problem, because if you change one variable, you change the result proportionally. Don’t worry, I’m leaving my slide rule in my pocket (for now).
Let’s start with the obvious, by just putting less film on the pallet. That can take two forms: fewer wraps, or using a thinner gauge of film. If you are using conventional film, this will likely lead directly to load failures during transportation. Loss of the product due to load failure doesn’t really improve sustainability. Some high-performance films will reduce the amount of film (film weight per pallet), and load failures may not be as much of a factor, however, they are much more expensive, so your cost per pallet increases. In addition, because they are being stretched further, web breaks become an issue as they can dramatically constrain production. One more variable in the equation is the condition of the wrapping machine. If it is not performing properly, more film may be needed to compensate. So, to reduce plastic content, you may pay more per pallet while constraining production throughput.
But what if, instead of following the conventional path, we use science to solve this math problem?
Force is required to stretch the film. The amount of force needed varies with the percentage the film is stretched. Eventually, the film reaches a point where it breaks. If you plot the force over distance, you have what the film manufacturers refer to as the ultimate strength curve. There are some other factors that must be considered as you stretch the film. The further the film is stretched, the more “brittle” it becomes. This means it is susceptible to punctures and web breaks caused by sharp box corners or tier sheets, and/or corners, splinters, or nails in the pallet. So, to maintain your load containment standard, you can use fewer wraps, but you must stretch the film further. Only high-performance films will allow you to do this. But every variable you change also changes the result. So, you pay more per pallet because high-performance films are much more expensive. In addition, the more you stretch it, the more web breaks you will encounter. I guarantee operators will adjust tension downward to eliminate web breaks, which further increases cost per pallet, reduces load containment, and, in the end, you don’t achieve the reduction in plastic content that you expected. So, what looks good on paper seldom translates to reality.
Now, let’s see what we get if we use a little science to solve this math problem.
We use a special resin formulation that has very specific properties (force, puncture resistance, and tear propagation). In other words, we know exactly how this film will perform under all conditions, and we know what percentage we must stretch it to yield the optimum containment force. The next challenge was to prevent the web from breaking as we stretched it much further than other films. We accomplished this by using two rolls of stretch film, one full web and one split web. We route the bands of the split web through a device that mechanically narrows them by rolling the band edges. The edges have now become reinforcement filaments and are incorporated or laminated into the full web as it passes through the pre-stretch rollers of the wrapping machine. It exits the carriage as a single “reinforced” web. Now, if it is punctured, the tear stops at the next filament, preventing the web from breaking on the wrapping machine. The reinforcement filaments also increase load containment performance by eliminating additional stretch left in conventional films. This allows us to reduce the wrap count, and since we stretch the film so much further, we use far less (50%-60% less) film, while also providing substantially better load containment.
So, the patented Rapid Bander will allow you to meet your sustainability goals by reducing plastic content while at the same time, improving your load containment, and typically reducing your cost per pallet. This is a well-proven technology, not only in our lab, but in the field, with thousands of installations, and success over many years. And just think, it all started by solving a math problem!
Thanks for asking!