Aluminium is used in packaging as it is highly malleable. It can be easily converted when at a thin layer normally between 6-9 microns which are the common thicknesses. AL acts as a total barrier to light and oxygen, odours and flavours, moistness and germs and so it is used broadly in food and pharmaceutical packaging including long-life packs (aseptic/retort) for drinks, soups, stews, tuna, pet food and dairy goods as allows storing without refrigeration when processed via retort or aseptic in some instances.

One critical thing is to monitor flex cracking so the use of other plastics on either side is recommended. It also allows for fantastic graphics when printed as you get great density.

Biaxially Oriented Polypropylene is a version from the PP family. It’s also a popular choice for the durable and convenient plastic used for flow wrappers for bread, crackers, biscuits, and snack packaging with variations of metallised structures for products from chippies to popcorn and muesli bars.

One of the most common types of plastics in food packaging is polyethylene terephthalate or polyester. Also referred to as PET, this plastic is known for its strength, lightweight build, and crystal-clear colouring.

The product is responsible for creating the shiny, smooth, and durable coatings you’d find on many of your favourite food products, often as the outer layer that is printed on in laminated pouches and films. It is often coated with products to give a higher barrier. It is also used for semi-rigid applications and for blown bottles.

Used in semi-rigid applications and for bottles, the “R” stands for recycled, and in most food applications using RPET, it will have 80% recycled content in the packaging.

Crystalized PET is commonly used for ready-meal trays as it becomes a dual ovenable material that has transformed the ready-meal market.

If you’ve ever enjoyed a carton of ice cream or a splash of milk in your morning coffee, you’ve likely encountered high-density polyethylene plastics. On a chemical level, HDPE is a thermoplastic polymer comprised of HDPE.

It is one of the world’s most versatile plastics. As such, petroleum features in an impressive variety of applications. When it comes to food packaging, you can find this jack-of-all-trades plastic in freezer bags, juice bottles, pouches, and sachets.

You can also find HDPE in products like water bottles, margarine and butter tubs, and box liners. Its high impact resistance and melting point are part of what make HDPE plastics so popular. If that wasn’t enough, the durable plastic’s reputation for tensile strength and impressive density-to-strength ratio also contributes to the material’s incredible usability and longevity.

Linear low-density polyethylene is another plastic found in a variety of food packaging solutions. Casually referred to as LDPE, this material is a thermoplastic and its formula comprises a compound called ethylene monomer. Its chemical makeup makes LDPE translucent, flexible, and durable.

LLDPE is a great material for a wide range of manufacturing applications and flexible applications and it is often the carrier or sealant layer as it is a highly durable material, a valuable asset in the creation of numerous types of food packaging.

Nylon film has excellent characteristics and can be used for a variety of high-grade packaging. It has high tensile strength, anti-puncture strength, excellent flexibility, and resistance, high gas and aroma barrier properties, good transparency and gloss, excellent printability, and a broad operating temperature range.

Therefore, PA film is especially suitable for the packaging of perishable foods like frozen and cooked foods, vegetables, agricultural products, aquatic products packaging, medical supplies, and electronic products packaging.

Like most of the other plastics mentioned, PS is a thermoplastic. It’s naturally transparent and can come in solid form or as a rigid foam material (think Styrofoam cups). PS is ideal for a variety of commercial purposes, so the list of food packaging that uses the plastic is extensive but in New Zealand, this is being fazed out. This once was the most common plastic used in food packaging.

If you enjoy slapping a dollop of sour cream on all your ready-to-eat meals or making cheesecakes from scratch, you likely encounter polypropylene, or PP, plastics regularly. Similar to its counterparts, PP is a thermoplastic. It’s durable, shiny, and can withstand heat.

Chemically, PP is an addition polymer created through a combination of propylene monomers. Regarding food packaging, PP is in your sour cream and cream cheese tubs. You might also find it in your yogurt packets. Its ability to withstand harsher temperatures comes from its impressively high melting point which made it rise to fame as a microwavable plastic.

Polyvinyl Chloride was a highly used material in food packaging especially takeaway containers, meat trays, and thermoformed semi-rigid but has now been banned for food contact products in New Zealand and many other countries. A derivative PVDC is a widely used barrier coating and additive in food packaging which means the material is not recyclable via soft plastics systems and schemes.

Ethylene-Vinyl Alcohol (EVOH) is a clear, flexible material that can be a copolymer or a coating and features excellent resistance to cracking. It is used almost exclusively as a barrier layer that prevents oxygen and other gases from entering or leaving a package. Because many edible products can react negatively or even spoil when exposed to oxygen, EVOH is very common in food packaging.

On the other hand, fragile products, such as chips in a pillow bag, typically need some type of gas to serve as a cushion and prevent them from being crushed in shipping and handling. EVOH is especially necessary in these applications as oxygen needs to be kept out of the package, but the nitrogen or other inert gas that is pumped into the package needs to be kept in. This superior resistance to gas permeation is what makes EVOH an essential material for many flexible packaging operations.

Metallised plastic films often serve as a more affordable alternative to aluminum foil and are produced by coating a PET or OPP film with a thin metallic layer (typically aluminum) or a metallised vapor. Using this method, metallised films are able to benefit from many of the strengths of aluminum without paying a premium. Metallised polyester (METPET) and vacuum metallised polyester (VMPET) are two of the more popular options. Metallised polypropylene (METOPP) is also popular in the film industry, but it differs significantly from polyester options.

Much like aluminum foil, these films can function as a barrier layer to block out moisture, gas, and light, making them good for everything from dehydrated goods and salty snacks to powdered drink mixes. While clear packaging is more common in medical applications, metallised barriers can help ensure medical tools and consumables remain sterile and undamaged until the package is opened. They can also be used to give packaging a reflective quality for added design appeal.

While everyone is familiar with paper, not everyone is aware that it can play a big role as a barrier layer for flexible packaging. While it does little to keep out moisture, gases, or chemicals on its own, paper does an excellent job of blocking UV radiation and keeping salty foods and products with a high-fat content from going rancid. It is also considered to be a more environmentally friendly material choice by many brands and consumers, and it can serve as a popular aesthetic element in many markets, such as artisanal foods.

While ink is mostly used to convey information on a package and catch the eyes of passersby with bright colors and designs, it can also serve a practical purpose in the structure of a package by blocking light transmission. Each additional material layer in a flexible package reduces margins for the converter, but knowledgeable printers know how to utilize ink as a layer in and of itself to reduce expenses, shipping weight, and storage space within their facility while still ensuring the packaged product arrives at the consumer in optimal condition.