Overwrap

Polywrapping is an automated process of wrapping an item in a clear or printed polythene film. Polythene is fed from reels under and around a product. The two edge are then brought together and heat sealed together and crop sealed at the top and bottom to create a "pack".

Items that can be polywrapped include: direct mail, books, brochures, catalogues, CDs, guides, magazines, periodicals etc.

The size of items which can be polywrapped will vary from machine to machine but as a general rule items as small as 2pp A6 card or up to 60 mm A3 items are within tolerances. A number of items of similar of smaller size to the original can be machine fed onto the polywrapping line. Because these items are placed on top of the product they are called onserts.

There are principally three type of film available:

• 'Standard' Polythene - Used currently for the majority of mailing packs.
• 'Degradable' Polythene - Increasingly used, the film is extruded from the same material but a very small amount of degrading agent is added. Typically 'Oxo-degradable' (breaks down in the presence of oxygen) degrades in a short timescale, leaving no fragments, no methane, and no harmful residues. This film cannot be recycled.
• Bio-degradable' - Starch based or biobased (hydrodegradable) film. Less commonly used due to the price being 3-4 times that or standard film.

The above films are available in a variety of thicknesses from 15mu (microns) to 150mu although polywrapped packs are rarely over 50mu (more typically 25 or 30mu)

Polythene can be recycled at a few accepting centres and used to make such items as garbage bags, fertilizer sacks, chairs, benches, tables, pallets etc.

Advantages

The use of polythene has several advantages over envelopes:

• Polythene is lighter and significantly cheaper than a C4 paper envelope. A reduction in weight could mean the addition of an additional leaflet or promotional item at no extra postage cost.
• Clear polythene allows recipients to view the contents (such as a magazine cover) prompting them to open immediately if the item is of interest or expected (i.e. subscription magazine)
• A pre-designed opaque film with an address window, the use of spot or full colour can create a more immediate and professional impact.

Disadvantages

• The recipient may not want the contents to be visible to everybody
• In the United Kingdom there are very few recycling sites for polywrap

External links

• The World Leader in Print Media Distribution Systems
• A mailing house with polywrapping lines
• The website of British Polythene Industries
• MacDonald Mailing, a leading print, mailing and polywrapping company
• One of the few companies recycling polythene film
• A mailing house speciliasing in short/medium runs
• International mailing house with 5 Sitma polywrapping lines