Do You Really Need That Metalized Film Layer?

Often times when we buy flexible packaging with metalized film and it works, we put that process on automatic.

The “if it isn’t broken, don’t fix it" mentality creeps in and so years can go by without asking "is this the most cost effective and efficient flexible packing solution?”

We are here to disrupt that thinking. Oftentimes flexible packaging is over engineered, meaning there are structural changes you can reconsider in order to save on material costs and environment impacts, while maintaining the integrity of your product.

Metalized Film

Metalized films have extremely thin coatings of metal (typically aluminium) deposited on a plastic film in the form of vapour.  They should not be confused with actual metal layers as with “foil.” The base film for this example is made from Polyethylene terephthalate (PET), commonly known as Polyester in fibre or fabric applications.

Our most common flexible packaging solutions that use metalized films are pouches, sachets, stick packs, bar wrappers (excluding cold seal) or any vertical/horizontal form roll stock.

The industry standard for metalized film structures consists of the following:

1. 48g PET film
2. 48g Metalized PET film or foil
3. 3mil PET Sealant Layer

The reason for metalized films is first and foremost the need for high barrier protection. This comes in the form of Oxygen Transition Rate (OTR), Moisture Vapour Transition Rate (MVTR), and Ultra Violet Light (UV). Some brands choose to use metalized to be incorporated with the design, playing with colour on top of the metalized PET gives a feel of high end product.

Non-Metalized Film

If your product does not require protection from UV light, then consider the following structure:

1. 50g ALOx coated PET film
2. 3mil PET Sealant Layer

Our 50g PET film has a very thin and transparent layer of Aluminium Oxide (ALOx) vacuum deposited on one side and a acrylic slip coat. This replaces the OTR and MVTR barrier of the metalized film. No other wet coatings or primers are required. By doing this you reduce your overall film weight from 96g, down to 50g (4mil, down to 3.6mil). Most importantly, you remove the entire layer of metalized film.

What is Aluminum Oxide aka Alumina?

According to Wikipedia, Aluminum Oxide is derived from a rock called Bauxite which is a mineral strip mined in sedimentary rock. Aluminum is further made by reducing aluminum oxide to pure Aluminum through an electrolysis process.

Appearance and Function

In order to keep the same thickness of the original package, some companies choose to increase the sealant layer from 3.6 to 4mil. The good news is that this structure does not change the function on your production and filling line. Secondly it does not look or feel any different in the consumers hands; Unless you have been using the metalized layer to enhance your artwork. Instead companies will opt for working with a white sealant layer for their base layer.

Sustainability

Since the same process of mining is employed for extracting ore to create both Aluminum Oxide and Aluminum, the environmental savings comes from the absence of the electrolysis process. Our own operations, add further environmental savings in the form of less processing time, and only one lamination as opposed to two on our machines.

Down-gauging or light weighting your packaging in this manner aligns with future state regulations. In addition, PET films will be more attractive for recyclers once methods become available for processing multi-laminated flexible films.

To further your sustainable packaging options, consider using Post Consumer Recycle (PCR) content films, including metalized.

Recyclable Packaging

According to the Association of Plastic Recyclers (APR):

"ALOx Barrier coatings are accepted as “Preferred” additive when applied directly to a Polyethylene (PE) film for recyclability. The effects of the acrylic layer on recycling are not known.

Metalized layers are extremely thin coatings of metal deposited on the film as a vapor.  They should not be confused with actual metal layers addressed as “foil” in this document.  Metalized layers are not removed in the recycling process and are melted and blended with the PE.  This may cause material discoloring.  In some cases, a metalized film will be detected early in the recycling process by metal detectors designed to protect machinery from catastrophic damage.  Metal detectors may not be able to differentiate between a metalized film and a solid metal part, so the entire package may be discarded rather than accept the risk.

Vapor deposited metal layers are frequently applied to oriented polypropylene (OPP) or polyester (OPET) films for flexible packaging laminations that may end up in the PE recycling stream. Since PP and PET have higher melting points than PE, negative effects of these metallized laminates may occur in the extrusion and melt filtration processes. However, when deposited into recyclable substrates like PE, oriented or not, mono (OPE) or biax (BOPE), the layer of aluminum metal is at the nanometric level, which should not present any significant risk to recyclers on the melt filtration step."

Cost Savings

Each packaging situation is unique, however, if you determine that you can remove the metalized PET and don’t change anything else, there is the potential to save 20 - 25%. On the other hand, if you opt for a thicker PET, paired with the ALOx PET, costs become comparable yet environmental savings are still present.

Food Science

If you are unsure if you can remove the metalized film layer from your flexible packaging, contact your food science lab or contact our packaging specialists to analyze you structure. From there we can determine your requirements for high barrier and extended shelf life stability.

The options are endless! Let us help you discover if there is an option that fits your flexible packaging needs.