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:
•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.
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.
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.
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’s latest “Tech Bites” video explains how proper clearance and pressure adjustments optimize horizontal flow wrapper performance.
Clearance and pressure settings on horizontal flow wrappers are critical for achieving quality packages, minimizing downtime, and controlling costs. We’ve noticed that the differences between clearance and pressure, and the proper occasions to adjust each of them, are not always clear to those making these adjustments. Greener’s latest “Tech Bites” video and blog post differentiate the function and adjustment of clearance and pressure. Read more