Emery Oleochemicals and Sukano replace food pack coatings with antifog tech

21 Oct 2022 --- Emery Oleochemicals and Sukano have developed an antifogging compound for direct food contact PET packaging as a replacement for coatings. The compound has been designed for all kinds of Coex films (rigid and oriented) with PET as the core layer and Sukano ́s co-polyester compound in one cap-layer of the film extrusion line A/B structure.

Previously, “there has been no other antifogging solution for PET other than coatings. Emery developed the antifogging agents, Sukano produced compounds and films, and both tested antifogging performance,” Dr. Christian Mueller, global technical market manager at Emery Oleochemicals ́ Green Polymer Additives, tells PackagingInsights. 

Emery Oleochemicals, the global manufacturer of natural-based chemicals, has experience creating other antifogging agents – but this is their first and claim to be the first – non-coating solution. Sukano aided as a global specialist of additive and color masterbatches and compounds for polyesters, biopolymers and specialty resins. 

The compound is designed to be used in cold applications to prevent fogging in packaging surfaces that hinders a clear view of packages contents. Fogging occurs when moisture-containing products such as fruit, vegetables, or meat are packed in a tight container, and water condenses on the surface, often forming droplets.

Better antifogging tech lessens water droplets on food that can lead to food spoilage and waste. Antifogging innovation
The companies collaborated for two years of research and development before completing the compound. They tested it in PET lidding film applications, PET clam shells and thermoformed lids and trays, all of which achieved desired results. 

The active antifogging function keeps the film transparent even after exposure to several different environments. 

“Antifogging for PET is a very challenging application in polymer additives. At a very early stage, we understood that to be successful in producing effective antifogging agents for PET, we must find a strong masterbatch specialist partner,” says Mueller, attributing the compound’s success as a result of partnering with Sukano.

Customary antifogging products are a coating overtop film that creates an extra production element with another operational step to filmmaking. Typical solution-based layers are also inactivated when the surface is washed. 

“Internally added antifogging agents are known to create processing issues in PET, such as a strong viscosity drop of the polymer melt. Clouding the final article is another obstacle,” adds Christian Schanzer, global product manager of antifogging additives compounds at Sukano.

Foggy food 
The companies state that fogging “makes packed food look less fresh and less attractive, but sensitive applications can even be damaged or have their shelf life reduced due to water droplets.”  Emery Oleochemicals celebrates partnership with Sukano in creating optimized antifogging compound solution over standard coatings. 

Antifogging agents eliminate the potential of food spoilage from water droplets by inhibiting their formation through a homogeneous, transparent water layer. Water that forms inside food packages can cause the contents to rot and spoil, meaning the implementation of better antifogging agents could aid in reducing food waste. 

The key benefits of this new internal antifogging agent for PET are transparency, durability, and homogenous effect associated with easy handling, as no additional machinery investment is required to make it work. 

“Additives that work well in flexible vinyl meat wrap films or polyolefin films do not necessarily work well in PET. Polarity, crystallinity and other physical or chemical characteristics of the base polymers are too different, and the additive molecule design needs to consider that,” says Dr. Annika Heinrich, technical development manager at Emery’s production site in Loxstedt, Germany.

As a final test, the compound’s effects on plastics’ recyclability were tested. The plastics that included the compounds were ground, washed and submitted to additional heating conditions, simulating the critical recycling steps of a PET tray dedicated recycling stream, according to the Petcore TCEP protocol.

By Sabine Waldeck