Welcome to the latest Kenray Blog looking at the 6 Key Principles of forming, filling & sealing quality packages on VFFS Packaging machines. We are delighted to be joined by our Corporate Partners Greener Corporation.

1. Product Flow

Let’s start at the beginning with Product flow. Problems occur most often when the product is:

 large in relation to bag size
 inconsistent in size or shape
 lightweight
 oddly shaped
 or with rough outer surfaces

Bottlenecks occur when product strings out as it moves from the inlet cone into the narrower confines of the forming tube. In extreme cases individual product “charges” can bridge together. These product flow issues slow down production speeds, create blockages, and cause leakages when product gets trapped in the seal.

On forming tubes with integral cones, the product dose is slightly staggered, so it passes through the bottleneck faster and stays more compact.

2. Forming Set Design

Forming sets should be designed according to your product, package design, machinery, and film specifications. Make sure that this optimal design is accurately and consistently replicated when you order replacement parts or specify formers for multiple machines, lines, or locations.

3. Roller Position

Machine adjustments are also critical for producing quality packages. Misaligned film rollers prevent the film from making full contact with the forming shoulder, causing wrinkles, creases, and package distortions that reduce shelf appeal and cause seal problems.

4. Film Drive

Poor package quality is caused by film drive issues such as belt adjustment and forming tube alignment

5. Former Wear and Damage

Wear or damage to the former lip or shoulder can also distort the package.

6. Sealing

By fine-tuning your forming and filling operations you will improve both package appearance and seal quality.

Leakages
The end seals on packages produced by vertical baggers typically vary in thickness. Most have a lap or a fin seal, and some are designed with gussets. Unintended wrinkles or pleats may, at times, be unavoidable. Leakages, when they occur, often follow channels at the intersections between two and multiple layers of film and at the corners.

Sealing Jaws
Sealing jaws must transfer enough pressure and heat to seal across these channels without crushing, cutting, or distorting the end seal.

• Pressure

In order to create uniform sealing pressure, the serration profile of your sealing jaws should be designed according to your package specifications, machinery, and running conditions.

• Heat
Sealing jaw temperatures are often increased to improve seal quality, but this can create hot spots that overheat and distort the package.

Jaws manufactured from Dura-Therm material provide more responsive, consistent heat transfer across the package to help seal off-channel leakages without overheating the film.

• Wear and Damage
Jaws that are worn, damaged or contaminated with products also create inconsistent pressure and heat transfer that cause seal problems.

To learn more about forming and filling on vertical packaging machines, contact Kenray Forming on +44 (0)1530 400 100. We can also offer remote training and consultancy to help you optimize your packaging operations.

Kenray Forming_sets formadores para envasadoras verticales

For more details on sealing  Jaws, consult the wide variety of Greener “Tech Bites” posted on their P3 Solutions Blog, or contact Greener Corporation.

For further information, please contact Mark Evans on +44 (0) 1530 400 100 or email perform@kenrayglobal.com