Plastics can be found in most packaging, due to their innumerable qualities. They are used in many sectors: health products, perfumes, cosmetics, cleaning products and, above all, foodstuff. Plastics are sometimes even invisible…Have you noticed the fine layer of polyethylene incorporated in the paper wrapping your butter? It is there to preserve the butter’s taste. The same applies to cans: a polymer varnish suppresses the taste of the metal and also keeps the can airtight. Plastics also add extra strength: this is the case with glass bottles which have a polymer coating to make them more impact-resistant. It is also present in sugar sachets because it allows the two ends to be welded to keep out humidity. In short, most packaging needs plastic.
Plastics manufacturers spare no effort !
Consumers want products that are fresh, healthy and appetising…but they are also wary of preservatives. But, as we know, food is not inert and even has an annoying tendency to go bad quickly.
For the food industry, it comes down to squaring the circle: offering foods that keep as long as possible and in optimum condition whilst meeting consumer expectations.
So these industrialists have turned to packaging manufacturers, mostly those producing plastic packaging, for the appropriate solutions.
The technical prowess of barrier systems
The last decade has seen the development of sophisticated packaging techniques called “barrier” systems which have the particular quality of prolonging the lifespan of products, especially by preventing oxygen from entering the packaging. Here too, the adaptability of plastics is a major advantage as the diversity of their composition means that they can be designed to suit the characteristics of the foods that they are to protect. Various layers of different materials can be used (up to six) according to the needs of the product and the intrinsic quality of each plastic: impermeable to oxygen or humidity, mechanical strength, but also suitable for shaping or printing on, visual appearance, etc.
That is why the packaging for cheese is not the same as for instant coffee, yoghurt or meat. We should also consider the case of red meat, which is particularly susceptible to spoiling: when it is packed on a tray of polystyrene foam, its storage life is only about three days. With a more impermeable multilayer system comprising three polymers (type PS/EVOH/PE), it will keep for ten days. Another example: fizzy water bottles, some of them made of PET and polyamide to preserve their little bubbles longer!
All I need is the air that I breathe !
Second quality: Modified Atmosphere Packaging (MAP), designed for better preservation of fresh or processed foods.
It has been all the rage for a long time on supermarket shelves in the form of salads in plastic bags. Most of them are packed in plastic bags filled with nitrogen, because as it is inert, this gas prevents oxidation (you may recall that nitrogen makes up 80% of the air that we breathe). The same applies to salted peanuts: their packaging, often consisting of a film with a layer of aluminium (PE/aluminium/PET), contains carbon dioxide and/or nitrogen to prevent a rancid taste due to the oxidation of peanut oil. And to go back to our red meat example, here it is just the opposite! The air in the packaging is enriched with oxygen to preserve its red colour, which is a visual criterion indicating freshness to the consumer.
Plastic packaging is extremely functional, guaranteeing the safety of the contents. The lids and caps that are used are practical, airtight and reliable. Consumers can be sure that the product that they buy has not already been opened. This is the case when you hear a “pop” when opening a little pot of baby food. If it is made of glass and the lid is metal, it is the plastic seal in between which guarantees that the container is airtight. It is the same with the caps of plastic bottles: the collar that breaks on opening shows that it is tamper-proof. Caps for bottles of detergents can only be made of plastic: only plastic can deliberately make these containers difficult to open, for child safety.
All five senses awake
The added value of a product also includes a good deal of creative marketing. That is why brands make the most of the sensorial qualities of the packaging, and here too plastic packaging can match the creator’s ingenuity, so wide is the range of possibilities.
In fact, it offers a range of colours, shapes and textures which are limited only by the designer’s imagination!
Even the olfactory potential can be brought out, as is the case with a punnet of strawberries or raspberries which is extensively perforated for excellent ventilation but also to cleverly allow the tempting aroma to escape…
The decoration constitutes an essential differentiation lever, as indicated by Dalila Safir and Marjorie Vincenti of the Albéa communications department: “In the field of tubes we have developed a technology which allows printing with a “photo” effect directly on the material. The visuals are more lifelike than in reality. In addition, the various coverings that can be produced with plastics offer a host of visual effects such as matt & gloss, transparency, iridescent, metallic, etc.”
Nor is the sense of hearing forgotten, as the little ‘pop’ mentioned earlier with the pot of baby food is designed to show you that you are the first person to open it … subconsciously and automatically you then have a feeling of confidence in the quality of its contents.