What makes consumers choose one food product rather than another from the supermarket shelf? What makes them pick up a specific bag of salad or packet of steaks? Could it relate to the product looking presentable and fresh in its clear plastic packaging, whereas the deselected item was packed in an unclear and moisture-covered packaging?
Sometimes otherwise appetizing foods can’t be seen clearly due to fogged packaging and lose their consumer appeal. This may eventually lead to the product becoming unsalable and subsequently thrown away, adding to the growing issue of food waste. Almost one-third of all food produced worldwide gets lost or is wasted each year in food production and consumption systems, amounting to 1.6 billion tonnes of food worth about $1.2 trillion of waste. According to UK sustainability charity Wrap about 40% of the bagged salads bought in Great Britain every year are thrown out, a whopping 178 million bags.
Consumers want to see what they are buying, which means that transparent food packaging films and containers must ensure long-lasting clarity to maintain the aesthetic appeal of the packaged product. Palsgaard is addressing these needs with a range of surfactants designed to reduce the fogging and the accumulation of static electricity of the packaging material.
Varying conditions of ambient humidity and temperature in transportation and storage can cause the formation of condensation droplets and fogging on the inner packaging surface, unless it is made from a material modified with an effective anti-fog additive. Although Einar® plant-based anti-fog additives cannot prevent the occurrence of moisture, they lower the surface tension on the inside so that condensed moisture will spread as a continuous thin film across the surface. While this preserves a clear view of the food, it also protects its freshness and extends its shelf-life.
Another issue for manufacturers occurs during on-shelf storage of plastic packaging for products with longer shelf-life. The plastic can become dusty during long storage, as plastics tend to attract dust through their static properties. This is particularly visible on coloured containers, bottles and canisters Food producers need to address these problems as they can have a severe impact on consumer acceptance.
Anti-static and anti-fogging properties
Fogging and dusting problems can be reduced or eliminated by adding anti-fogging and anti-static properties to plastic packaging by means of additives tailored for additive masterbatches and polymers. These additives have the same chemical structure as food emulsifiers and both the hydrophilic and lipophilic aspects work as surface active ingredients in plastics. They migrate to the packaging surface and prevent fogging and dust formation. The flow of the additives to the surface is constantly renewing and continuous as they are a part of the packaging material, thereby providing a long-term solution. The additives need to be homogeneously distributed in the plastic packaging to achieve good performance. This can be difficult, though, as their concentration is relatively low, such as 0.4% for polyethylene film. To target these issues, the functional additive masterbatch has been developed. It obtains a high concentration of the active substance, pre-dispersed into a polymer.
Palsgaard’s food approved anti-fogging and anti-static additives are made from either polyglycerol ester of fatty acids or distilled monoglyceride (DMG), known as glycerol monostearate (GMS) in the polymer industry, and are designed to prevent the formation of water droplets or the collection of dust on the food packaging.
The anti-static and anti-fogging performance in the final packaging will depend on numerous variables, such as the raw materials of the active agents, the type of polymer used – polyethylene or polypropylene – and the complete recipe as well as the production process and final properties of the plastic. Similar to food emulsifiers, Palsgaard's polymer additives are produced from different vegetable oils, such as rapeseed, sunflower and palm oil, and will perform differently. This makes it possible to develop tailor-made solutions to match the requests of the end-users.