Sealing Over Extra Layers of Film at the End Seal – part 4 of 4: Optimizing Crimper & Sealing Jaw Design

Matt Wojtech parts solutions, sealing January 15, 2018crimpers, downtime, Dura-Therm, Easy Seal, flexible sealing face, flow wrapper, fractured end seal, heat, leakers, mooning, packaging film, pressure, projects, sealing jaws, sealing theory, vertical bagger

There is no one-size-fits-all solution for the design of crimpers and sealing jaws on horizontal flow wrappers and vertical baggers; they should be specified according to the packaging film, products, and conditions of your packaging operation.

This post, the last in our four-part series, reviews design options for crimpers and jaws. The optimal combination of serration patterns, materials, and special features can dramatically improve seal quality and productivity when sealing across extra film layers at the end seal.

Transitions on the end seal between varying thicknesses of film created by the fin seal, lap seal, gussets, and wrinkles make it more difficult to maintain the operating window necessary for quality seals:

Too little pressure leaves gaps, or leakers, at these transition zones.
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 at transition zones or “moons,” before the seal can set.

Package Quality Issues_vertical baggers_Greener Corp

The end results can be packages that fail to protect the product or have little appeal to consumers, as well as lost production time spent attempting to meet package quality standards.

Crimper and Sealing Jaw Design Options

Troubleshooting Extra Layers of Film at the End Seal – Part 3 of 4

Mark Green "Tech Bites" videos, people solutions, process solutions, white papers September 18, 2017backlash, cleaning, clearance, crimpers, flow wrapper, fractured end seal, heat, knife, leakers, pressure, productivity, seal quality, sealing jaws, vertical bagger

Optimizing Set-Up and Adjustment of Crimpers, Sealing Jaws, and Knives

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.

Troubleshooting Extra Layers of Film at the End Seal – Part 2 of 4

Andrew Dennis forming, parts solutions, people solutions, process solutions, sealing April 24, 2017forming set, forming tube, leakers, mooning, packaging film, productivity, seal quality, vertical bagger, wrinkles & creases

Refining and Eliminating Wrinkles and Creases on Vertical Baggers

Varying thicknesses of film at the end seal can cause sealing problems, especially at the transition points of multiple film layers created by the fin or lap seal, gussets, wrinkles, creases, and at the corners. Applications of pressure and heat must be great enough to cause the sealant layer to flow into and seal off these voids. However, excess pressure can easily crush or split the end seal, while overheating distorts the seal and can cause poor hot tack, where the film springs back open, or “moons,” before the seal can set.

Package Quality Issues_vertical baggers_Greener Corp

The operating window for creating quality seals can be elusive, resulting in packages that leak, are distorted, and have little appeal to consumers.

An important step in troubleshooting these issues is to eliminate unintended wrinkles and creases. This post, the second in a four-part series, will examine this process on vertical baggers; Part 1 covered these issues on horizontal flow wrappers.

Any impediment that disturbs the even flow of film can distort packages and create leakers; a combination of factors is often to blame. To find the causes of these problems and fix them we recommend a comprehensive analysis of design, condition, and adjustment, beginning with the film roll and following along sequentially as the film is unwound, formed, filled, and sealed.

Film Contact with the Forming Collar

The wing of the forming collar should completely and evenly support the film as the flat web is formed into a tube. Too much, too little, or uneven tension can cause wrinkles and creases.

Troubleshooting Extra Layers of Film at the End Seal – Part 1 of 4

Matt Wojtech people solutions, process solutions February 14, 2017crimpers, fin seal wheels, flow wrapper, heat, leakers, packaging film, pressure, seal quality, serrations, wrinkles & creases

Refining and Eliminating Wrinkles and Creases on Horizontal Flow Wrappers

Varying thicknesses of film at the end seal can cause sealing problems, especially at the transition point between two and four layers created by the fin seal, gussets, wrinkles and creases, as well at the corners. Applications of pressure and heat (if applicable) must be great enough to cause the sealant layer to flow into and seal off these voids. Excess pressure can easily crush or split the end seal, while overheating distorts the seal and can cause poor hot tack, where the film springs back open, or “moons,” before the seal can set.

Package Quality Issues_Greener Corporation

The operating window for creating quality seals can be elusive, resulting in packages that leak, are distorted, and have little appeal to consumers.

An important step in troubleshooting these issues is to eliminate unintended wrinkles and creases. This post, the first in a four-part series, will examine this process on horizontal flow wrappers; Part 2 considers these issues on vertical baggers.

Troubleshooting Intermittent Seal Quality Issues

Mark Green parts solutions, people solutions, process solutions, sealing December 7, 2016backlash, cleaning, clearance, crimpers, Dura-Therm, Easy Seal, flexible sealing face, heat, kevlar scraper, leakers, pressure, seal quality, sealing jaws, serrations, temperature

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.

Following is a list of procedures that will help you troubleshoot intermittent seal problems. You can find additional details by clicking on the links or images in each section: Read more