Shrink Wrapping, Shrink Packaging or Bundle Wrapping is a packaging process in where a group of products is wrapped in shrinkable plastic film which, after exposing to hot air, holds the products firmly together for transport, as a sales unit or for ease of inventory management.
Advantages of shrink wrapping:
Our website is designed to help you decide if and what shrink packaging process and machine is right for your product and environment. However, one has to be aware that not all products can be transported and handled by machine and not all products can be shrink wrapped. Contact Autopack and use our experience to quickly find a competitive solution for your needs.
Shrink packaging like any packaging process involves: Preparation of wrapping material (film),Preparation of product,Enclosing (wrapping) in a sleeve of LDPE film then Shrinking / cooling and discharge.
Each part of the process including the product itself can effect the speed, versatility and quality resultant pack. However, the two main factors are: product collation and wrapping system.
Polyethylene (PE) in its low-density form (LDPE) is the best suited plastic film for general shrink wrap packaging. This is because it is relatively strong, inexpensive and can be made with correct shrink ratio for Sleeve Wrapping. (70/20)
The shrink wrapping process consists of 3 steps:
There are two ways of wrapping the shrink film around the products.
Weld Bar Sealing
This is the traditional way or Sleeve Wrapping using two, top and bottom film rolls. The two are joined to form a film curtain. When product is ready, it is pushed through, Welding Bar (Sealing Bar) comes down to form a sleeve on the collation of product at the same time cutting the film and rejoining the curtain for the subsequent pack.
This process uses single film roll, where a pre-cut sheet of film is wrapped around the product, with the loose ends overlapping beneath the pack. The overlapped region is partially fused in the shrink tunnel at the same time as rest of the sleeve is shrunk to enclose the contents.
The main advantage of Weld Bar type machines is lower cost and smaller footprint.
The main advantage of Overlap machines is higher throughput, better suited for printed film, they tend to be longer and more expensive.
For additional pack strength or ease of handling, a cardboard pad or tray can be introduced under the product before being shrink wrapped.