In this Greener Tech Bite we analyze six sealing jaw carbon impressions and explain how each was used to troubleshoot problems on flow wrappers or vertical form fill seal baggers. Read more
In this blog post and Tech Bites video we outline solutions to achieve repeatable quality and productivity on horizontal flow wrappers and vertical baggers across all production shifts, multiple packaging machines, and different plant locations.
When cutting problems occur on horizontal flow wrappers during a production run, what are the best procedures to get packaging lines up and running again and to keep them running? Minimizing downtime, producing consistent quality packages, and managing costs require a balanced approach that includes:
- Knowing which “quick-fix” adjustments will get knives cutting without causing additional problems and downtime. (Faster and easier is not always the best solution.)
- Broad-based, P3 Solutions that consider the entire packaging process to:
• Understand how each adjustment affects the whole system.
• Eliminate procedures that don’t work.
• Diagnose and correct the ultimate causes of problems. (Many issues stem from a combination of factors.)
• Implement solutions that help prevent cutting problems from occurring in the first place and help you Pursue Zero.
The first two parts of this series explored the potential problems created by end seal wrinkles and creases and ways to eliminate or reduce them on horizontal flow wrappers (Part 1) and vertical baggers (Part 2). In some situations wrinkles or creases are unavoidable, and, even without those issues, most packages have the inevitable transition between multiple film layers created by either a fin or a lap seal. This can make it more difficult to achieve quality seals, and attempts to do so can lead to additional issues:
• Excess pressure can easily crush or split the end seal.
• Overheating distorts the seal and can cause poor hot tack, where the film springs back open, or “moons,” before the seal can set.
The operating window for creating quality seals can be elusive, resulting in packages that leak or are distorted and either fail to protect the product or have little appeal to consumers.
This post reviews some of the detailed solutions in Greener Corporation’s Knowledge Center that will help you seal over extra layers of film at the end seal by refining the set-up and adjustment of crimpers, sealing jaws, and knives.
When end seal issues such as leakers or splitting occur, an important initial step is to determine where, and how often, the trouble shows up. For problems that occur inconsistently—perhaps leakers on every other package, or splits only on the top or trailing end seals of the package—you need to determine if the bad seals show up randomly or according to a pattern. Do the problems occur on every package? On both ends of the package?
Start out by collecting a series of packages produced by the machine during production conditions. Number the packages sequentially and mark the machine flow direction. If you are working on a horizontal wrapper with multiple crimpers, label each pair (ex: A, B) and mark each seal according to the set of crimpers it came from. Now you can trace the problem seals back to the place they occur.
Set-up procedures for knives and anvils can vary according to the make and model of the packaging machine, knife adjustment style, and other factors. There are, however, some general principles that make these adjustments more effective and efficient, reducing downtime and parts costs.
♦ Optimize Knife Design
- Knives ground on a diagonal, or bias–whether they have a zig zag or a straight cutting edge—require less pressure to cut so they are easier to set up and typically last longer.
- Zig zag knives with smaller (more) teeth are also easier to set up and provide longer life.
♦ Set Up the Crimpers First
- Clearance and Pressure Adjustments required to create a good seal can impact the knife and anvil set-up.
How do you know your adjustments are correct?
This “Tech Bites” video and blog post from Greener Corporation explains how carbon paper can help you optimize seal quality on horizontal wrappers and vertical baggers.