Polyeteenisaumautuvan kalvon antifog-ominaisuuden kehittäminen

Humidity tends to condense as water droplets and fog on the inner surfaces of food packaging films. This phenomenon is common especially when product with high mois-ture content is packed in plastic package and stored in cold conditions. A great amount of water droplets makes visual appearance of package unattractive and unhygienic, and additionally, fog prevents consumer from seeing the packed food supply. The surface of polymer film is hydrophobic by its nature, in which case condensation of water droplets on the surface of film can be prevented by changing the surface to hydrophilic. In this case, condensed water droplets spread as uniform water layer on the surface of film, and transparency of film is improved. This phenomenon is called antifog effect. Hydrophilic-ity of surfaces of films can be improved with different antifog additives and coatings. Additionally, surfaces of films can be treated with several physical methods. Good antifog properties are difficult to achieve and maintain for the resealable polyeth-ylene structure. This is because antifog masterbatches utilizing polyethylene carrier are not well applicable, and on the other hand, antifog lacquers do not anchor well on poly-ethylene surface. Antifog property should maintain at acceptable level for six months, which is the demanded shelf-life of the product. However, recent tests have shown that antifog performance significantly reduces as a function of time. Goal of this research was to find out, how functionality of antifog lacquer could be im-proved on the surface of polyethylene film. The dilemma was approached by studying functionality of antifog lacquers of two different suppliers on resealable polyethylene structure. Antifog properties, sealability and static contact angle were studied from film samples coated with studied antifog lacquers during test period of six months. During this research, differences were detected between durability of antifog perfor-mances of studied antifog lacquers. One of studied antifog lacquers maintained its anti-fog properties for desired six months. Sealability properties of all antifog lacquer coated film samples were at acceptable level. It was detected that dilution ratio of antifog lac-quers affected the studied properties