Bag Style and Forming Complexity: VFFS Speed Considerations Part 3

Emily Brogan
Mon, Sep 21, 2020


High speed VFFS packaging operations have many nuances due to their many variables. So much so that we’ve covered these variables in three separate articles now. Just to recap: in the first, we discussed the relationship of your bag width and head space and how that has a direct impact on filling speed (AKA the speed of your entire operation). In the second article we unpacked product characteristics and what products are more or less conducive to high speeds, and covered technical solutions for problematic factors like stickiness, abnormal shapes and products that tend to float.

All of these first sets of variables aside, why are there are trade offs for speed as the level of complexity goes up for package styles? The quick and probably assumed answer to this question is that film plays a large factor but what other factors can be burrs under the saddle of your packaging workhorse?

    • Handling of the Film
    • Control of your Sealing Parameters
    • Machine/HMI Recipe Repeatability

Bag Styles for Evolving Consumer Demands

Premium pouch packaging styles often involve premium film materials. For many stand up pouches, its often recommended to form them using a sturdy material to maximize shelf appearance, stability and merchandising consistency. Stand up pouches have high expectations to meet and using the same type of film that would be used for a standard pillow bag would likely result in slouching or unstable stand up ability.

For salted snack packaging that satisfies the ever increasing consumer trend of on-the-go and convenience eating, many producers are migrating to resealable stand up and often doy style stand up pouches, which are known for their excellent full-panel billboard areas and solid base for stand up ability. For the RoPack®, the patented Rovema doy style stand up pouch, using Stabilo® seal ridges on the bottom lend itself to the sturdy base that retailers love but requires a multi layer film with an inside sealant layer.

For premium retail coffee packaging, a popular package type with many coffee roasters also involves Stabilo® seals, with four corner seals that offer excellent stand up ability. What about the film material allows for this result? Coffee products, due to their high oxygen sensitivity, already require practically iron-clad barrier properties and an inside sealant layer, but its also recommended they have an outside seal layer as well to tack bottom fin flat to the bag for additional stability.

Importance of Proper Film Handling

Proper film that allows you to meet your shelf presentation expectations is key and of course having barrier properties that meet you and your retailer’s shelf life management goals for your products is imperative. So what are some best practices for maximizing your production speed while also being a good steward of your premium material?

Properly handling of the film material as it is running through the bagger is essential, especially when working with valuable structures. By using vacuum pull belts and a power film unwind, you minimize any excess strain that is placed on the film as it makes it’s way through the labyrinth of guide rollers. Secondary benefits of this technology is that it allows the use of larger film reels, equating to less reel changes and downtime and also decreases the stress and wear on the film draw down belts.

Maximizing the control of your film is the name of the game here and having complete control of your sealing parameters after it’s made the long journey through the film carriage is key.

Extended Sealing Time ≠ Slowing Bagger Speeds

Thicker films do require more energy to achieve adequate seals with the following tactics often being used:

  • Dialing up the heat of the seal jaws which can cause delamination and wrinkling of the film
  • Dialing up the pressure of the jaws with can actually squeeze out the inner sealant layer of cause fracturing of metalized film, both potentially causing micro-leakers in the seals.
  • Longer dwell times on the seal that allows the heat to penetrate all the way through.

Rovema uses the third method that achieves the highest quality and consistent seals but that doesn't equate to a slow packaging operation. Our patented sealing technology, Premium Seal® coupled with our D-motion sealing allows you to maximize the dwell time of the sealing process as well as integrate two different sealing pressures in one cycle. By using completely servo driven seal jaws with no reliance on springs to drive force, the jaws can apply very light pressure to thicker films to preheat the inside sealant layer before applying force.

This allows for wrinkle free, delamination-free welded seals that are considered the strongest in the industry. And by using D-Motion sealing as opposed to traditional rotary circular sealing, that amount of dwell time can be fully adjusted as well to the needs of your film

Reliable Consistency with HMI Recipes

Most packaging machines are required to adapt to different situations. The actual product being packaged may not differ much, if any, but often they need to run different package sizes or even something as incremental as light vs dark roast ground coffee, where the actual product densities vary (if this sounds odd, check out this coffee frac pack article) which require changeover time and programming modifications.

Many modern VFFS machines have “recipes” in the HMI that allow for repeatability of setup, basically baselining the parameters for different product runs. This is huge for minimizing the amount of time needed for changeovers as well as maintaining the consistency of your packages to stand the test of time and any potential operator and maintenance turnover.

Minimizing the amount of changeover time and minimizing material usage for customers is a driving force of many of Rovema’s innovations. Automatic film tracking was created to address the excessive time and number of cycles that packaging equipment would take to finally track correctly as the last step of the changeover process. By tracking the film along the entire film carriage and the entire film carriage itself moves automatically, not just the back, can account for any offset. Changeover time can be cut drastically and the technology helps avoid downtime or package rejects during runs as it actively manages the film position.

Success For The Whole Team

Trade offs of speed with bag style complexity will be a factor for any producer for the simple fact that time is money and the more packages that you can get out the door every day only lowers your overhead cost per unit. With the added perceived risks associated with package complexity, it’s no mystery of why Marketing and Operations team innovation meetings can potentially reach deadlock verdicts due to their differing priorities.

Marketing teams want to satisfy customer demands and differentiate their products while Operations teams want to run product efficiently and without surprises. Partnering with capital equipment suppliers that have deep knowledge of the priorities of both sides of the boardroom table is key. These suppliers have the insights and motivation to invest in technologies that make both teams successful and help them sleep soundly at night.

I hope that this series was able to give you a deeper understanding of the intricacies of your VFFS machine, your packaging operation and what kinds of conversations we are having with customers every day as we consult them in building out the best VFFS solution for their products, stakeholders and their own customers. As the market continues to evolve and new challenges arise, we continue to address them with new innovations.

If you would like to discuss how your overall equipment effectiveness or bagger speed could be improved upon, we would love to start a conversation with you. We understand that time is a hot commodity but conversations like this can more than compensate you. If you'd like to speak with an expert, fill out the form below or connect with a live person now in the chat.