Shrink Wrapping Process
The basic point of this process is to put shrink film around the item preceding shrinking. There are two standard types of wrapping:
- i) Sleeve wrapping – Shrink wrapping bottles, boxes and so forth
- ii) Over-wrapping – Shrink wrapping the jugs, boxes and so forth. It involves complete wrapping of the product before you shrink.
This form of wrapping is most appropriate for auxiliary and tertiary packaging. The process is effortlessly mechanized as it uses ease material and requires low work input. Sleeve wrapping is promptly connected to standard molded items that are ordered in large quantities but has to be handled easily for distribution, warehousing or palletizing.
Sleeve wrapping is performed placing two rolls of sheet shrink film. The closures of these sheets are then heated fixed together framing the vertical curtain. The item then channeled through the film curtain located next to welding bar.
The welding bar has been designed to descent before the pack then to separate the sleeve from the remaining film and to make the film curtain be standby for the next cycle.
The sleeved pack at this point goes to the shrink burrow where film shrinking happens.
The resultant pack in this process will is not entirely enclosed. Each finish of the pack has an opening because of the first wrap being just a sleeve.
Sleeve Wrapping Machines
An extensive variety of machines are available in the market. However, your decision should be determined by the nature of your products, size, and cost among other factors. There are simple machines that require a low-level operation. For this machine, a person is required to position an item, operate the jaw and initiate and release the shrinking process using the foot pedal or pull bar.
Then other shrinking machines require an administrator to operate the self-loader system with pneumatic help. The administrator positions the pack and starts the programmed welding cycle. Then there are medium speed programmed machines, in this case, all the cycles are initiated by the machine automatically upon arrival of the product.
Most shrinking machines of this type operate at a speed of 30 packs per minute. However, there are high-speed shrinking machines that operate up to 100 packages in every circle.
In over-wrapping an item is enclosed wholly in a perimeter sealing process that requires L-bar machines that can handle center folded plastic film. The total enclosure in this type of shrinking can be accomplished with the help of flat sheet film that is placed on the flow wrapping machine. Over-wrapping is most appropriate for low stature, rectangular formed items, for example, stationery, CDs, videotapes, magazines and so on.
When this process is done on an L-bar sealing machine, the film is fixed over the width and seals one of the fixed sides of the pack. Item is then placed between the layers of film and then channeled to the next station for sealing. Here the remaining sides are sealed to enclose the products.
From that point, the bundle is moved onto the shrink burrow transport to finish the shrinking process. Basic L-Bar machines are manually handled, but there are programmed models available.
Finally, there are L=Bar systems units that are all in one. In this case, the Sealing and shrinking are done together. The Sealing station comprises of a hood, where the item is encased with the film. Once the sealing is established, hot air is then blown around the pack to shrink the bundle. These machines are most appropriate in low-speed packaging, dispatch applications or offices.