The ultimate quality of the packages produced on horizontal flow wrappers requires a complex series of events to form and fill each package and move it through the packaging process. In the following post and “Tech Bites” video we explore the many steps that occur before and after packages are cut and sealed—from the product feed and film unwind through to the discharge belt—that must be fine-tuned to optimize seal integrity, package appearance, and productivity.
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.
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
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.
The corporate engineering department at a large, international company commenced a project to reduce material costs for a variety of products that are individually packaged on horizontal flow wrappers. Greener Corporation was invited to participate in a series of meetings that defined the project’s initial goals:
- To reduce the cut-off length for each package by reducing the overall seal width, thus allowing the product envelope to remain unchanged.
- To achieve material savings without degrading seal integrity or productivity levels.
- To achieve a project payback period of twelve months or less.
Greener Corporation has published a series of white papers devised to help optimize package quality and productivity on horizontal and vertical form fill seal packaging lines. In addition to helping you solve problems, these technical articles provide foundational information you can use to implement proactive improvements—an approach that helps deter problems from occurring in the first place.