Overwrapping as a term has many different meanings to different people. At its most generic level it refers to the wrapping of any product with a flexible wrapping material, be it aluminium foil, paper, heat sealable film or stretch film. In this way, when applied to machinery or packaging styles, it encompasses many different types of wrapping.
An overwrapping machine is a packaging machine which automates the hand wrapping process by wrapping a flexible packaging material e.g. paper or heat sealable film, around a rectilinear product or group of products. Envelope style end-folds are characteristic of overwrapping. Different techniques are available for sealing, though typically heat is used to seal film. Paper can be sealed with glue though it may have a heat-sealable plastic coat
Overwrapping fulfills three different functions. Primary wrapping is where the material is in contact with the product, for example a pack of loose playing cards.
Secondary wrapping is where the product has already been packaged using another style of packaging and the overwrap is then added on top, for example a box of chocolates where the cardboard box forms the primary wrap and the overwrap completes the package.
The third function is that of a transit wrap for a collation of loose products, for example a distribution pack of 12 cartons of toothpaste. In this example the overwrapping machine collates the tooth paste cartons and the overwrap keeps the distribution pack togther. Retail multipacks are becoming more common and overwrapping is often used to collate two or three items togther for retail sale, for example a twin pack of biscuits or mint cartons.
There are many different reasons for choosing overwrapping as compared with other forms of packaging. The most important are :