What are shrink bands?

Shrink bands are pieces of plastic casing that wrap around bottles and jars to prevent tampering. Their popularity grew in response to the product manipulating scare that Tylenol experienced in 1982, in which it is believed that someone in Chicago tampered with medicine bottles on store shelves. In an effort to warn and protect consumers, shrink bands were adopted. There are two types of shrink bands:

  • Tamper evident shrink bands allow a distributor or consumer to immediately recognize if a product has been opened because the plastic is damaged or removed.
  • Tamper resistant shrink bands have a level of difficulty to open them, restricting access to at risk groups like curious children and naughty pets.

Characteristics can vary, but most cover a product’s bottle neck where the closure meets the container. Shrink bands come in almost any color to match company brands and can even display logos or product information. While many are designed to prevent tampering, ease of removal by the appropriate population is still a concern. Perforation lines or pull tabs are incorporated on consumer products to facilitate access.

Sizing is standardized to ensure quality and accuracy. Shrink bands are measured by lay-flat width (LFW), cut length (CL) and thickness. All are measured in millimeters. If ordering shrink bands, be certain to request the desired finished circumference, not the original cut length.

Types of Shrink Bands

There are two popular types that differ by material: cellulosic and film.

Cellulosic shrink bands are also called wet bands because they are applied while wet and tighten as they dry. For that reason, wet bands are not accepted by the FDA for products that require tamper evident bands. Someone tampering with a product could simply wet the band then temporarily remove it. The product could appear to be unaltered by reapplying the band and allowing it to dry.

Cellulosic bands are manufactured from a mixture of wood pulp, plasticizers, humectants and colorant. After combined, the mixture is distributed from a die, cut and given an acid bath to promote coagulation. They are then ready for printing.

Film shrink bands are constructed from several types of resin: low density polyethylene (LDPE) or polyvinyl chloride (PVC). Unlike the cellulosic variety, plastic shrink bands are applied with a heat. Simply place the finished band around the product and use a heat source to tighten it against the desired region. The key to using a heat gun or hair dryer is consistent application, or even heat. Overexposing one side can cause irregularities or product failure.

For more information, visit Qorpak’s shrink band sales pages.