Go the extra layer

31 August 2020

If the primary purpose of packaging is to protect a good and help move it from manufacturer to consumer, then coating and laminating is responsible for protecting the packaging itself. Almost every protective requirement has a corresponding coating and laminate to provide that extra layer. In the current market, where safety and health are ever-present and protection from contamination on surfaces is front of mind, it is important to focus on the vital support provided by this technology. Matthew Rogerson looks at this essential part of the market in more detail.

It is unlikely that the average consumer pays any attention to the surface of their packaging in a supermarket or – in lockdown days – the packaging that comes into their house from online purchases. Most people are more outcome than process-focused, ‘I don’t care how it works, just that it works’. This is perfectly normal, as there are quite enough day-to-day concerns and thoughts to occupy the mind without needing to understand how a sandwich has extended its use-by date by two weeks, or even noticing that this has happened.

There are a lot of unsung heroes in the converting process, but coating and laminating must be one of the largest and least acknowledged. Partly this is because it performs its role beautifully, unnoticed but protective. It is a far-ranging role – packaging materials have a series of primary protective needs, from vermin and bacterial contamination to light moisture and gas barriers and chemical resistance (to protect from flavour or aromas mixing with the product).

Depending on what end result is desired, such as shelf life, protection through transportation or just that the product is used at the consumers’ convenience and is easy to hold, open and close, for example, will all shape which finish achieves these goals. Protection or preservation is especially important in a pandemic-confronted world where comfort and safety, which are so lacking in the news or around consumers, provides assurance. If something upends this feeling, for example, the virus is able to transfer to the surface of packaging and then into someone’s home, the fallout is extraordinary.

No errors allowed

While one might not need to know how something works, while it works, there is certainly little to no tolerance of error. By applying the right coating or laminate, or through the best use of multilayered films, protection can be provided. If this fails, consumers will immediately voice their displeasure across social media and the problem escalates dramatically.

Using the right tool enhances the end effect. Food packaging, where preservation and protection are key, relies on coating. An excellent example is in fast food, when they are open, the most important part of the process is to get cooked food to a customer and for them to enjoy it as close to freshly prepared as possible, in store or at home. The paper barriers that have been developed in the past few years mean that paper-flexible packaging can hold liquid, moisture and prevent gas passing through the fibres of the paper.

That old torn paper that was covered in grease and no longer held together is relegated to history and people get to eat delicious, hot burgers without them swimming in oils or stuck to their packaging. How about the barriers that go into PET to allow bottled drinks to prevent sunlight or oxygen or other unwanted interferences reaching the liquid inside? Or films that seal ready-to-eat meals, meats and protect frozen or freshly made pizzas in transit. Metal, paper, plastic and glass all seal that extra layer of protection.

The paper takeover

Pre-coronavirus, when the world’s focus was on the environment, there were a number of launches designed to help paper take over from single-use plastic. Whether it was Nestlé, moving out of plastic in Nesquik, Smarties and Yes Bars, through Hasbro, which is seeking to move all toy packaging out of plastics, to the most recent example by Signal (Phillips Lighting), which will be plastic free by 2021. They have achieved these goals through adapting specialist chemicals and laminates that allow paper to act like plastic or similar.

A previous issue with a direct material swap was that the incoming material would not perform the same. A paper bottle would be considered mad and discounted in favour of metal or glass or plastic, but thanks to work by Carlsberg, Coca-Cola and others, fibreboard paper bottles are possible. It is by using specialist coating and laminate that the product’s surface can hold liquid and keep out unwanted smells or flavours. While there was initially a follow-up concern that these products, by binding to the packaging, were making it impossible to stream and recycle them, recent launches still provide preservation and protection without causing further sustainability issues.

Handling is another area where it is crucial to provide the right finish or risk the product being damaged, unsafe or unusable. Examples include a coating that is used to ensure that glass bottles do not crack when they vibrate against each other in transport, or a non-slip laminate or coating, which means when a consumer picks up a pouch, pail, container or product it does not slip from their hands. Lucozade were well aware of this through its consumer research when it made its sports bottles non-slip using special coatings. It realised that customers were likely to have slick, sweaty or wet hands when exercising and the smooth finish of plastic would have made handling tricky, if not impossible. By allowing texture to the surface, the bottle can be opened one-handed without flying out of their grasp.

Smart functions

Enhancing the function of the primary packaging occurs time and time again. Whether it is the inside of the wrapper, which helps prevent chocolate in a bar from melting into the packaging, or the increasingly smart uses of coatings that can react to the presence of oxygen, light or flavours – and can be adjusted to suit requirements – and can be used by consumers to make sure their fruit is still good, or that meat is still securely vacuum-packaged. Coatings can go beyond pure protection to enhance the function of the overall package and the experience of using it.

Modern metal can coatings, for example, allow one to take a cold beer from a fridge without slipping from their hands due to condensation; it’s so ingrained in the experience of beverages that no one ever considers the technology needed to help this happen. Decorative coatings used on glass, which is difficult to print on, can magnify the enjoyment of the occasion and experience, and not drop the bottle. Carlsberg recently provided a unique method of holding six cans together without a plastic ring. The adhesive used combines with a coating that holds the cans together but can then be pulled off when consumers want to drink it.

The situation where the package is stored, used or sold factors into the best coating. A few years ago, Reckitt Benkisser had to change the lamination used on the labels in its dishwasher packaging as the lights in the supermarkets were reflecting off the labels into consumers’ eyes. The coating was protecting the labels and the package, it was fit for purpose and was doing its job, and yet in a supermarket shelf, suddenly this issue meant that they had to find a new coating to provide the same performance without this unfortunate side effect.

Perhaps the most incredible example of why coating and laminating is so important comes from the luxury perfume market. There were a number of reports of the labels being illegible and of messy presentation, where the decoration of highly expensive perfumes was running down the bottle. The fascinating and unexpected reason behind all of this was due to the presentation and sales process most of us are familiar with. The perfume itself, as it had quite acidic chemicals in its structure, was essentially eroding the paper labels and glass coatings on other bottles every time someone sprayed a test. Fortunately, by adding a lamination to the labels that was neutral to these sprays in the air, the luxury goods could continue to be sold at their premium price point.

It is for reasons such as these stated and numerous others available that there has been a surge in focus on ensuring that these precious coatings and laminates are not wasted. In the plant, when it is applied to surfaces, it is crucial that just the right amount is applied each time to make sure that the right amount of protection is provided. There is no need to add a double layer where a single will suffice and the cost implications can spiral whether too much or too little is used. Too little raise the spectre of contamination or not fulfilling its purpose, while too much and it’s a wasted resource, or it might even cancel out the performance of the coating or lamination.

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