TAGS: Additives for Packaging Surface Modification Sustainability / Natural Solutions
Sukano and Emery Oleochemicals announces the launch of their jointly developed PET antifogging compound for direct food contact PET packaging. Two years of intensive testing and simulations of end use applications in real life scenarios in research and development laboratories resulted in this new antifogging compound. It is formulated to be used at 100% in cold applications to prevent fogging in packaging surfaces.
The product is designed for all kinds of Coex-films (rigid and oriented) having Sukano´s co-polyester-compound in one cap-layer of a film extrusion line A/B structure and PET as core-layer. The resulting product performance is so robust that, even after orientation in several different ratios, the antifogging function remains active and integral, and the film remains transparent.
Inhibits Water Droplets Formation on Film Surfaces
Fogging, or the undesired formation of small water droplets on the surface of films, is a common problem when packing moisture-containing products such as fruit, vegetables, or meat in a tight container. When the water condenses on the surface, it often forms droplets due to the lower surface tension of plastic materials.
These droplets ‘fog’ the film and hinder a clear view into the packaging. This not only makes packed food look less fresh and less attractive, but sensitive applications can even be damaged or have their shelf life reduced due to the presence of water droplets.
Antifogging agents solve these issues by inhibiting the formation of water droplets through a homogeneous, transparent water layer. However, the PET food packaging industry is longing for an antifog performance in the form of a compound that can be used in their packaging materials to replace the painful existing coating process.
Antifog coatings are well known and in use but have the downside of adding another operational step to filmmaking. And typical solution-based coatings are inactivated when the surface is washed. As an internal additive in plastics, antifog additives work on polyolefins due to the migration readiness of the polar additive in the nonpolar polymer and the low glass-transition temperature.
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Used in Polyester Packaging Applications
However, polyolefins have limitations in recyclability and gas barrier performance. PET, on the other hand, is a well recyclable packaging material with good barrier performance and transparency. However, the current antifog additives on the market do not work in PET. Due to the polymer polarity, coupled with the glass transition temperature.
It is an extensive understanding of polyesters, molecule design and packaging processes that worked as the foundation for this new antifog compound for polyester packaging applications.
The compound additive was tested in PET lidding films applications, PET clam shells and thermoformed lids and trays. The final parts were then shredded, 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.
As responsible companies, the very natural step to evaluate the influence of such innovative technology in the PET tray recycling stream is in the core of the design principles of both companies. The tests reflected consumer habits and local countries demands, such as extracting or not the lidding film when the packaging is disposed of.
Source: Sukano