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Choosing Film for a VFFS: Mono-PE, Barrier Properties, and Sealability

The choice of film determines the shelf life, sealability, and annual costs of your production line. This guide covers the structure of packaging film, the difference between mono-PE and composites, sealability, and thicknesses ranging from 40 to 120 µm, as well as the PPWR initiative, which makes recyclability a purchasing criterion.

Table of Contents

The film is the most expensive consumable item in any vertical form, fill, and seal machine: Over its lifetime, it costs more than the machine itself. Yet film is often chosen based on price per kilogram rather than its performance in the sea. This guide outlines the key considerations: construction, barrier properties, sealability, and the sustainability trends driving the market.

How Packaging Film Is Constructed

Film for bags is almost always a laminate: each layer has a specific function. A carrier layer provides strength, a barrier layer keeps oxygen and moisture out, and a seal layer fuses shut at the opening. Standard laminates include PET/PE for dry products, OPP/PE for snacks, and PET/ALU/PE for products that absolutely must be protected from light and oxygen. Mono-PE is the exception: all layers are made of the same material, so it can be recycled as a single fraction.

Film Type Barrier Recyclable Typical Application
Mono-PE moderate Yes, one political party pellets, dry snacks
PET/PE good No, two political parties powder, cookies
OPP/PE fair to good no snacks, sugar
PET/ALU/PE excellent no coffee, dried meat

Barrier: How Much You Need

When it comes to barriers, more isn’t necessarily better. Oxygen-sensitive products like coffee require an oxygen transmission rate of less than 1 cm³ per m² per day; dry granules in a fast-moving supply chain can get by with mono-PE. Assess your product’s shelf-life requirements and choose the lightest barrier that meets them—every additional barrier layer costs money and reduces recyclability. For nitrogen-flushed packaging, outgassing is also a factor; see vacuum packaging or nitrogen packaging.

Sealability: behavior in the pelvis

The seal layer determines the temperature and pressure at which the film seals: PE seals between 120 and 150 degrees, PP between 140 and 170 degrees. If you mix different types of film or use different suppliers, the sealing range shifts, resulting in a seam that is only partially sealed. Stick to one film specification per product and do not reseal: a seam that has been heated twice is a weak seam. Contaminants in the seam—such as powder or crumbs—are the classic cause of leaks; more on this in the powder packaging machine-guide.

Thickness and Film Consumption

Thickness ranges from 40 µm for lightweight pouches to 120 µm for heavy-duty bags containing sharp objects. Thicker film is stronger but more expensive and stiffer at the forming shoulder. The savings rarely come from thickness but rather from width and length: every millimeter of film width across the roll length translates to kilograms per year. That math is outlined in film consumption — Read this before you negotiate the price of the plastic sheeting.

Sustainability as a purchasing criterion

The PPWR initiative from Brussels makes recyclability the standard rather than a marketing tool. As a result, single-material packaging becomes the default for what can be packaged in it: dry products with moderate barrier requirements. For items that cannot be packaged this way—such as coffee and products with a long shelf life—a deliberate trade-off between barrier performance and recyclability is required, including potential solutions for sustainable packaging solutions. Ask your film supplier to calculate the costs for both options before you make a decision.

Frequently Asked Questions

Q: Can my existing VFFS be converted to mono-PE?

Usually, yes: mono-PE has a wider seal and requires an adjusted temperature curve, and sometimes a wider seal. Have a film test performed on the machine using your own product—an hour of testing can prevent months of sealing problems.

Q: How much more does recyclability cost per bag?

Mono-PE film is generally 5 to 15% more expensive per square meter than standard PET/PE, but it often weighs less while offering the same strength. Calculate per bag rather than per kilogram of film: the difference disappears in the total cost when the width is optimized correctly.

Q: How do I test a film before making a large purchase?

Three tests on the machine: a seal test across the temperature range, a drop test with the product onto concrete from a height of 1 m, and a transport test of a full pallet along your own conveyor path. Only then is the order placed—the same procedure as with Choosing a VFFS Machine.

Related pages

sustainable packaging solutions | vertical form, fill, and seal machine | film consumption | vacuum packaging or nitrogen packaging | Choosing a VFFS Machine


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Evelien

I am an expert with 16 years of experience and have completed more than 300 projects. My goal is to provide you with the most suitable packaging solution right away.

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