Issue link: https://cp.revolio.com/i/808614
Recipes are not just used to address strength concerns. They may also be chosen to help with warp control (no unbalanced liners), moisture transfer (use a specific coating), equipment handling (porosity specifications), etc. But all of these issues should be incorporated into a proper functional specification. If the specification is simply a paper combination or recipe, those other needs are lost (e.g. board with balanced liners might still be warped), with the associated risk that the package may not meet the real functional requirements. Using either paper combinations or BMC levels at best defines simple material properties, and typically those material specifications are too far removed from our functional spec to truly be useful. Material specifications provide no or limited assurance of good converting, and fail completely to incorporate the effects of handling in use. To survive the rigors of distribution we need to know the impacts from the distribution process as well as the point we start from with the box. Given that significant disconnect, it might be surprising that either approach could possibly work. But historically they have, more or less. The system built in high performance margins to cover for the gaps in understanding, at a time when the sins of the system were easier to hide. Few of us are willing to pay for that today. Performance Specification If specifying papers is not the best idea because of variations in the paper supply across the industry and across the world, and if the BMC provides a minimum value for only one parameter that might contribute to a box's overall performance, where does that leave us? The best way to specify a box is to build a performance specification based on the actual requirements on the box for product protection throughout the distribution environment. This approach may require extensive test protocols, and is not necessarily the easiest to implement. However, it is the best way to assure that the box will do what is required in the field. These types of specifications may involve compression testing, setting a minimum compression strength (BCT) for products that spend most of their time stacked in a warehouse. They may involve testing according to one or more third party protocols, whether developed by testing organizations like ISTA or ASTM, or by shippers like FedEx or retailers like Sam's Club. The customer may have even developed their own test routine that correlates well with damage they've observed in their specific distribution chain. Regardless of the source of the method, having an end use protocol is usually the most reliable way to guarantee box performance. Defining the performance criteria correctly provides the best opportunity for package optimization. Box performance depends on the structure of the box and its components. To get the right performance, we need to understand how the box is used, and we need to tailor the box to meet those stresses. Our goal as a box manufacturer is to make the right box most cost effectively to meet the actual end use requirements. The key to the entire process is for us as box makers to know our customer, their product, and their distribution process. We need to work together to define what happens to the box during its lifetime, in order to be able to understand any durability requirements as well as how much compression strength the box needs to have. Defining required compression strength is essential if we want to know what the ECT requirement is for the combined board or what papers to use to make the boxes at a particular manufacturing location (given their capabilities and paper supply). We can accurately estimate that compression strength only if we know what happens to the box all the way along its life, all the way through the distribution process, at every point that the customer, their warehousing system, and perhaps their customer and their customer's warehousing system, handles and maneuvers the box on the way to the end user. This must be a collaborative process. Let's examine a brief example of how wrong we can be if we don't understand the distribution environment. We have a large customer who asked us to make a box for them that would allow them to increase their stack height. They were stacking their units with seven layers of boxes, they wanted to go to nine high. Our designer created a box and our plant ran a large order. The customer called back shortly thereafter, complaining that the box was terrible and would only stack five high! Photos of the customer's operations showed column stacks with staggering amounts of misalignment, boxes hanging way off pallets, and other distribution problems. We asked the customer to stack a unit of product on the floor in their warehouse, and it lasted twice the required time, stacked nine high, with no damage. One might think this proves that the box we made was fine, and that it was the way the customer used the box that was a problem, but in fact this example shows a systemic lack of coordination and collaboration. True, the customer had terrible unitizing practices, but fundamentally the problem was our fault together. We didn't do our homework, and designed a box without taking into account the distribution environment, without fully understanding the functional spec. After all, that spec wasn't truly "stack nine high," but rather was "be able to be stacked nine high and transit through our distribution environment." Box compression strength is not the only important parameter for box performance, but since most products are warehoused for some period during their distribution, BCT is a key parameter for most boxes. BCT best correlates to unit-load package performance for storage ista views • April 2017 • www.ista.org Specifications – Defining the Result Not the Path > CONTINUED FROM PAGE 15 16