What is Machine Sleeve Wrapping
Sleeve Wrapping is sometimes called transit or distribution wrapping, the strength and durability is important, rather than appearance. The process is used on trays of cans and bottles, large boxes or print work. It is used to collate products into specific quantities and keep them clean and undamaged during delivery and storage. Heavy duty polythene is wrapped around the consignment, heated to 200 degrees then cooled, providing a tight, robust pack. The heat treatment does not affect the product inside whatsoever and both ends of the sleeve are left open (bulls eyes) to allow parcels to be lifted by the wrap.
Shrink wrap is sometimes used to wrap up books, especially adult-oriented ones and certain comics and manga, mainly to prevent them from being read by minors.
Software on carriers such as CDs or DVDs are often sold in boxes that are packaged in shrink wrap. The licenses of such software are typically put inside the boxes, making it impossible to read them before purchasing. This has raised questions about the validity of such shrink wrap licenses.
Shrink wrap is commonly used as an overwrap on many types of packaging, including cartons, boxes, beverage cans and pallet loads. A variety of products may be enclosed in shrink wrap to stabilize the products, unitize them, keep them clean or add tamper resistance. It can be the primary covering for some foods such as cheese, meats, vegetables and plants. Heat-shrink tubing is used to seal electric wiring.
Shrink bands are applied over parts of packages for tamper resistance or labels. It can also combine two packages or parts.
Sleeve wrapping machines designed for producing transit packs in PE shrink film. Two rolls of flat PE are sealed producing a "curtain" of film. The pack travels into this "curtain" of film producing a sleeve around the pack, which shrinks tightly in the tunnel.
The most commonly used shrink wrap is polyolefin. It is available in a variety of thicknesses, clarities, strengths and shrink ratios. The two primary films can be either cross-linked, or non-cross-linked. Other shrink films include PVC, Polyethylene, Polypropylene, and several other compositions.
Coextrusions and laminations are available for specific mechanical and barrier properties for shrink wrapping food. For example, five layers might be configuration as EP/EVA/polyester/EVA/EP, where EP is ethylene-propylene and EVA is ethylene-vinyl acetate copolymer.
Shrink wrap is also commonly used within more industrial applications using a heavier weight shrink film. The principles remain the same with a heat shrinking process using a hand held heat gun. The following shrink wrap applications are becoming more widely used and accepted:
- Industrial shrink wrap containment of large plant equipment/components,
- Scaffold wrap containment of buildings/bridges,
- Building temporary shrink wrap structures for storage or other business operational uses,
- Marine shrink wrapping of boats and other vehicles,
- Shrink wrapping of palletized freight
- Disaster contingency and relief projects such as damaged buildings/roofs.