In contrast to industrial shrink-wrap, which is essentially a thicker gauge polyethylene film used in case over-wrap, retail display shrink film is available in a choice of 3 different types of films.
Because retail display shrink films are used to over-wrap, or unitize, products that are placed on retail shelves for consumers’ choice and purchase, they need exceptional optical properties, excellent seal-ability and shrink-ability properties, as well as a reasonable cost per package.
There are three types of films available in the marketplace, PVC, polyethylene and polyolefin.
PVC, or poly vinyl chloride, was, arguably, the first available film in the retail industry. It is able to be manufactured to be bi-axially oriented, meaning it can shrink in both the machine direction and in the horizontal direction in equal shrink percentages, or it can be made as a uni-directional shrink, shrinking primarily in the machine direction. It has excellent optical properties, with high clarity and high gloss, and, using relatively low temperatures, extremely easy seal and shrink characteristics. It also exhibits low shrink force properties, which can be varied. It is also available in various gauges, from extremely thin to relatively thick.
PVC has the capability to be oriented either bi-axially or uni-directionally, which allow it to be used in a very wide base of applications. It’s low temperature characteristics are certainly an important benefit in packaging temperature-sensitive items, and its low shrink force is preferred when packaging flexible products such as sponges or brochures to keep them from buckling.
PVC though, has some very crucial downsides. It’s main problem is, ironically, its main attribute. Because it seals and shrinks in low temperatures, it is very unstable to store. If a distributor, or user, inventory PVC shrink films in the wrong environment, the film will, automatically, and unilaterally, shrink in storage. In addition, Transparent PVC film requires specially equipped packaging machinery to be properly sealed. In addition, many European and multinational manufacturers have banned the use of PVC films for perceived ecological reasons.
Thus, PVC shrink film is a film with declining, and more limited, uses, and with limited supplier availability.
Polyethylene retail display shrink film is available only as a uni-directionally oriented film, with is primary shrink force in the machine direction. It does not posses exceptional optical properties, and is not available in extremely thin gauges. It is FDA and USDA approved for food and pharmaceutical applications, as well as easily and readily recyclable.
It’s primary benefit is its relatively low-cost. Historically, polyethylene films have been the lowest priced packaging material available. But, because of its limited optical benefits, it is used primarily as an industrial shrink film, as opposed to a retail display shrink film, where extreme clarity and gloss is essential. In addition, its lack of bi-axial orientation properties limits its use to only certain packages. It’s very soft modulus precludes its use in very thin gauges on high-speed equipment. It is, however, readily available from hundred of film manufacturers and suppliers.