Dan Schmidt, Business Development Manager, Muller
Since Wal-Mart’s Sustainability Initiatives were first introduced in 2007, sustainability is a subject manufacturers find hard to avoid. For packaging manufacturers and suppliers, the added pressure to “go green” has only escalated over the years with customers unwilling to lower their expectations for them to meet varying sustainability goals. However, more companies are also realizing that implementing more sustainable practices isn’t just improving the environment, but also their bottom-line. For example, companies using petroleum based products are being greatly affected by rising oil barrel costs and have had to reduce usage to minimize costs. For stretch wrappers, these factors are all too familiar.
While packaging sustainability is predominately focused on reducing primary packaging material and increasing cube utilization, the end-of-line stretch wrapping process is critical to achieving optimum product delivery and reducing waste. As another step in the supply chain, it can’t be ignored if companies are looking to meet industry demands and achieve greater overall production efficiency. Advancements in equipment and technology are making it easier to reach sustainability goals while minimizing costs.
Reduction of materials is practiced in the name of sustainability. The reduction in primary packaging has put greater demands on stretch wrapping operations. Manufacturers are no longer just wrapping cardboard boxes of can goods. For most manufacturers, stretch wrapping has become essential for products that create unstable loads such as water bottles and open top display boxes.
As we have gone from boxes to trays to pads to nothing but shrink wrap, manufacturers have become more reliant on the end-of-the-line stretch wrap to make sure their product makes it to their customer intact and unharmed. Stretch wrapping may be the last operation before the product leaves the production facility, but it is the very first thing the customer sees when it enters their facility. Therefore, increasingly, stretch wrapping has become recognized as a critical component in making sure a product arrives in the condition intended. Most companies have already made significant investments upstream of the stretch wrapper, but any improvements (and the costs) will be wasted if the product arrives damaged.
It’s easy to understand how reducing film consumption is good for the environment. Less waste in landfills, reduced oil demands of producing plastic resins, and decreased energy costs associated with manufacturing the film are all green benefits to help meet growing sustainability initiatives. However, how to reduce film usage when stretch wrapping and avoid load damage can be challenging.
This article will provide a variety of solutions to minimize film usage, optimize load containment and improve efficiencies while at the same time, improving sustainability impact.
Thin is in
The most obvious way to reduce film consumption is to use a thinner film. However, moving to a thinner film without properly analyzing if it will work for the particular application will often result in an increase in film usage overall. In addition to the likelihood that a manufacturer has to compensate by using additional film to maintain the integrity and security of the package, a thinner film that is inappropriate for the application also creates the possibility for film breaks which will almost certainly increase overall film consumption, as well as slow productivity.
The good news is that recently several high quality, thinner films have come to market that can effectively reduce film usage without compromising the integrity of the load. Muller recently introduced the ReducerTM line of stretch films. This high strength, thin gauge film is produced using a new, proprietary formulation and compliments the proven, high quality Eliminator cast and ST blown films. When evaluating any new film, thorough testing with the new film and intended application and performing, at a minimum, an ASTM standardized force to load test is essential. Similar testing can also be performed to ensure the proper number of wraps is being applied.
Add Tension to Your Load, Not Your Work Day
An overlooked opportunity to limit waste is by applying proper tension to the load. To put it simply, most stretch wrapping machines have a tension adjustment that affects how tightly the load will be wrapped . It is important because if you don’t apply enough tension than you run the risk that the loads will topple over in transit. If you apply too much tension it can “squeeze” the film too tight around the load and damage the product or increase the probability that the film will break. When film breaks occur it is common for operators to “fix” any stretch wrapper issue by lowering the tension. In a study by Muller, a customer could see as much as a 10% increase in film usage when wrapping a load under low tension settings versus high tension settings using the Octopus wrapper. When applied to an average manufacturing scenario where 200 loads are wrapped per day, the result is nearly 1,000 lbs of film wasted annually. In a similar test using a used turntable wrapper, film usage increased 60% when wrapping under low tension compared to high. This is because under low tension you allow the film to recover and spring back, as opposed to when it is kept stretched under high tension. Spitting out film at low tension may be good for wrapping empty PET bottles that are prone to crushing under the lightest of force, but the majority of loads would be better served by allowing for optimal tension throughout the wrap cycle. By applying just the right amount of tension at various points on the load, manufacturers can rest-assured that they are reducing product damage while simultaneously lowering film costs. Instead of operating with a singular tension setting, variable tension control allows for increased tension at locations on the load that require extra hold (the base of a sturdy box) and lighter tension where reduced force is beneficial (sharp corners, the top of an open box). With the continuing changes in primary packaging design, it is crucial to have a system that offers flexibility and variability in order to optimize the stretch wrapping function.
For example, Muller not only offers variable tension control on their Octopus machines but, integrated with their OctoMAX™ system (highlighted below), they can also loads were wrapped and quickly identify where changes need to be made. The variable setting control eliminates film breaks and reduces usage by optimizing the settings based on the load configuration and containment needs. As film type, load dimensions or pre-stretch requirements change, the wireless function and monitoring system further make it easy to adjust to new settings. The wireless control also minimizes components and maintenance adding additional cost-saving benefits.
Measure, Monitor and Act
To really understand and quantify the benefits of any change made, having a way to record the performance of the film and equipment is essential. With retailers increasingly looking for proof that a manufacturer is making strides in its sustainability promise, stretch wrap equipment manufacturers are beginning to add monitoring systems to their machines that will measure and display at the HMI the precise amount of film that was applied to each and every load. Systems such as OctoMAXTM by Muller, will not only display the information at the HMI, but it will send an e-mail notification when too much film is applied and includes a secure web portal that the user can utilize to track historical trends, produce a variety of valuable reports, and help diagnose the root cause of issues.
Monitoring tools enable the user to keep a close eye on film usage and machine settings to help drive down the cost of stretch wrapping operations and simplify maintenance. It can even be utilized to compare the performance of two different types of films. As the old adage says, “What gets measured, gets done” and is a great way to ensure that the pre-stretch performance promised, is actually delivered. In addition, providing this data to customers and retailers is a great way to show that requirements are being met.
Optimize the System
True optimization and savings comes from looking at the stretch warp operation in its entirety – film, equipment and service. The return on investing in a simple service audit of your existing equipment can be tremendous. Speaking to your suppliers and finding out what upgrades are available is an essential component to improving sustainable practices.
As customer demands for greater packaging sustainability increase and rising material costs effect everyone’s bottom-line, taking a look at the entire supply chain is increasingly important. Overall, recent advancements in how the film is paid out, tension control, variable frequency drives, and wireless communication have created new opportunities to reduce film usage and improve overall efficincies, as well as reach your sustainability goals.