General design of the forming collar of the vertical form, fill and seal packaging machine using the finite element method

Abstract

The basic part of the vertical form, fill and seal packaging machine is the forming collar. The forming collar provides the shape over which packaging film is smoothly formed at high speed into a cylindrical shape. Describing the forming collar geometry and hence its design is, however, remarkably difficult. This paper presents, for the first time, a flexible methodology for calculating the complete geometry of the film rather than the usually non-complete collar over which the film is formed. That is, a methodology to calculate the film geometry over the collar including the seam along which the film is longitudinally sealed. The film geometry is calculated such that it has minimum deformation energy. Advantages of the proposed methodology include its great flexibility to generate collars with different configurations for different needs. Among the collar generation methods reviewed, the proposed methodology is the first that can systematically consider all collar configuration parameters such as the seam configuration, general package cross-section, flat or straight part of the collar, collar back angle, etc. A means for obtaining the exact collar geometry is also demonstrated. This enables right-first-time and repeatable collar production and reduces the time and cost for producing next generation packaging machines.

An Empirical Investigation into the Influence of Sealing Crimp Geometry and Process Settings on the Seal Integrity of Traditional and Biopolymer Packaging Materials

“…What is obvious when viewing the sealing envelopes for the test materials and crimp design is that the maximum values are generally obtained close to, or at, the peak seal temperature and dwell time configurations. In other parts of the form–fill–seal process where variants of forming takes place, the CoF is a dominant factor. In the seal closure area, it is surmised that it is the combination of a higher CoF and bending stiffness that affects the ability of the jaws to close at lower pressures, such as that shown with PLA.…”

“…As with any machine–material interaction scenario, it is important that all factors, which might serve in the sealability of the respective films, be measured and controlled. Previous studies have shown that the bending stiffness and the coefficient of friction (CoF; crimp material against film) have effects where forming and crimping take place. Hence, these were also measured and are given in Table .…”

“…With such systems, material is fed from a roll and converted from its planar (web) form via a forming box/shoulder into a tubular form with a small overlap that is sealed. Once the material has been pulled past the box/shoulder, sealing crimps come together and seal across the web. This means that the material now presents a ‘pocket’ into which product can be inserted.…”

Modelling the Material Flow and Web Tension in the Vertical Form–Fill–Seal Packaging Process

“…Whether there is some physical phenomena here remains an unresolved question. However, this is a second-order effect in comparison with the other effects present and does not invalidate inequality (5), which allows for possible variations in the coefficient of friction.…”

“…Ideally, the material should not deform as it passes over the collar and into the tube. Most design methods are based on the (differential) geometry of the collar and tube surfaces (although a recent approach seeks to minimize deformation of the film itself and use this to obtain the collar surface). The basic shoulder geometry can be studied in terms of the intersection of conical surfaces .…”