Heat shrink plastic labels for packaged foods, beverages and other consumer products are rapidly gaining momentum as marketers seek to differentiate their products on crowded store display areas and shelves. Covering nearly the entire surface of a bottle, heat-shrink labels are already identifiable with buyers of coffee creamer, flavoured milk and drinkable yogurt. Heat shrink labels are also finding applications in packaging of juice, bottled water, pet food, pharmaceuticals, cosmetics, lawn-care and auto-supply products.

A recent market research study indicates that the global market for heat shrink labels is expected to grow between 10-15 % between 2005 and 2010. Heat-shrink labels compete with paper, heat-transfer decoration/decals and in-mould labeling techniques. Shrink label materials is also at least twice as costly as the materials used in these conventional processes. But many consumer product packagers feel the advantages of shrink labels outweigh their extra expense. Several advantages are responsible for the high growth, notable among them are:
* Heat-shrink labels can provide eye-catching, high-quality, 360° wraparound graphics on a blow-molded plastic bottle    or container.
* They also cling tightly to just about any bottle shape. When extended to cover necks, caps and lids, the labels can add    tamper-evident features to a container.

There are two methods of applying heat-shrink labels: full-body shrink sleeves and roll-fed systems. Both involve placement of a plastic film, averaging 50 microns in thickness, around a bottle and the application of heat. The heat shrinks the film to the contours of the bottle. Shrink sleeves are the more common technology, but roll-fed techniques are catching up quickly.
Typically, films used in full-body shrink sleeves are extruded with a transverse orientation. These films, which are pre printed, are formed into tubes. Processors cut tubes to length and place bottles inside the tubes. Next, they run the bottles and tubes through a heat tunnel, which is usually heated by steam or infrared light. The heat causes the tubes to shrink, forming labels that cling tightly to the contours of each bottle. Typical film shrinkage levels range from 50-80%. This high shrinkage makes shrink sleeve systems useful when bottles have odd shapes. The most common resins used for shrink sleeve films are PVC, glycol-modified polyester (PETG) and oriented polystyrene (OPS).

PVC has been the most widely used heat-shrink sleeve labeling material, partly due to its lower cost as compared to PETG and OPS. PVC is also available in a broad range of shrink ratios and has a wide window of shrink temperatures (meaning that heating equipment does not need to be that carefully controlled). Specific gravities of the two resins are so similar that flotation techniques used in separation processes do not work well, making PVC labels difficult to separate from PET bottles during recycling. Hence environmental concerns have begun to erode the market for PVC in shrink labeling, particularly in Europe. PVC enjoys the benefit of large volume but presently has lowest growth potential. Compared to the average growth of 12.5% of all types of labels, PVC heat shrink labels will grow at about 6-7% level.

PETG heat shrink sleeves are more expensive than PVC shrink labels. They however have the highest shrink ratio among all shrink sleeve films (up to 80%). PETG is therefore more suitable for labeling bottles with complex geometries. The resin is also relatively benign in the environment. The bulk of PETG shrinkage occurs at lower temperatures than PVC and OPC, and PETG's temperature-shrinkage profile is also flatter; permitting more careful control of label shrinkage in heat tunnels. It is possible to make PETG shrink label films with a specific gravity less than 1.0- sufficient to separate the labels from more dense materials such as PET and PVC during bottle recycling. PETG label is expected to grow at more than 15% in the coming 5 years.

The favorable environmental properties of OPS and its shrinkage ratios of up to 80%, propel growth of OPS and helps OPS to take some share of PVC labels. OPS is less expensive than PETG and has exceptional clarity and gloss. OPS is particularly suited for labels for squeezable bottles. Because of its relatively low vertical shrinkage, OPS offers a highly consistent finish. OPS labels are building up volumes by eroding into the market share of PVC label and is expected to grow at 15% in the coming 5 years.

SBC (styrene butadiene copolymer) heat shrink film SBC film on account of its lower density offers 20-30% yield advantage over PVC, PETG and to some extent compared to OPS. Shrinkage of the K-Resin product begins at about 60° C and reaches a maximum of 75% at 95° C. A cyclic olefin copolymer (COC) heat shrink film can have as high as 90% shrinkage, offering an advantage over all the other heat shrink labels in respect to density. The film can easily be separated from PET containers by floatation method for recycling and recovery. For packagers who want a biodegradable heat-shrink label, a film based on polylactic acid (PLA) is available for this purpose. PLA is aliphatic polyester that can be derived from fermentation of agricultural products such as corn starch. High levels of clarity, printability and machinability are other assets of the PLA films . All these three films have a very small market share. However they are expected to show exceptionally high growth rates. Of course they will not achieve even 10% of the total global market at the end of 2010.