According to different packaging methods, shrink packaging machines can be roughly divided into three types:

1. open ends

It is wrapped in a sleeve with a tubular film or flat film before heat shrinkage operation. After packaging, there is a shrinkage opening at both ends of the package.

(1) When the cylindrical membrane is used, the opening of the cylindrical membrane is first propped open, and then the product is pushed into the cylindrical membrane by means of a slide, and then the membrane is cut off. As shown in Figure 1. This method is more suitable for wrapping cylindrical objects, such as batteries, paper rolls, bottles and cans. The advantages of packaging with cylindrical membrane are that it reduces 1-2 seam sealing procedures and has a beautiful appearance. The disadvantage is that it can not meet the requirements of product diversification and can only be applied to mass production of a single product.

2. Use flat film wrapped goods, using single flat film and double flat film wrapping two ways. The film should be wider than the object, wrapped in two flat sheets, that is, two sheets of film wrapped with the upper and the lower sheets. While the previous package is cut off, the two sheets are sealed. Then the product is pushed to the vertical film by machine or hand. After the sealing and shearing mechanism is in place, the other side of the product is sealed and cut off. After heat shrinkage, the two ends of the package shrink to form an elliptical opening. When using a single flat film, the flat film is first unfolded, and the wrapped product is fed into the middle of the flat film, forming a horseshoe-shaped wrapper, and then hot sealing lap sealing.

Food shrink packaging machine

Four sides sealed

The product is wrapped around a flat film or cylindrical membrane, and the lap joint is sealed. Used for packing products requiring sealing.

_L-type sealing method can be used with folding film, folding film in a drum, the film will be pulled out a certain length in a horizontal position, mechanical or manual will open the open end, push the product to the folding seam.

2. Pillow shaped bag packaging can be used for single flat film. The method is to use a single flat film, sealing the longitudinal seam into a tube, pushing the product into it, then sealing the horizontal seam cut off to make a pillow-shaped packaging or tie the two ends into a tube-shaped packaging.

_Double flat film four-sided sealing packaging is similar to the two-end open packaging, just equipped with two-side sealing device on the machine can be completed.

_wrapped with cylindrical membrane, only the cylindrical membrane cut off at the same time sealing, piercing, and then heat shrinkage. Sticking needles are often found beside the sealing device, and the air vents are punctured on the film during heat sealing, and the small holes are often closed by themselves after heat contraction.

Open at one end

Tray shrinkage packaging is a typical example. First, the film is made into a large square-bottomed bag, then the large bag is set on the stacked commodity tray from top to bottom, and then heat shrinkage. Place the pallet on the conveyor belt and cover it with shrinkage film bag. The conveyor belt is fed into the heat shrinkage channel, and the shrinkage package is completed after passing through the heat shrinkage channel. Its main characteristics are that the products can be firmly bundled in a certain number of units, not loose in the course of transportation, and can be stacked in the open air.