Analysis and development of the hottest shrink pac

Analysis and development of heat shrinkable packaging technology (II)

2) four side sealed

wrap the product around with flat film or cylindrical film, and the joint is sealed with lap joint. Used for product packaging requiring sealing

(1) the L-shaped sealing method can be used to fold the film in half, as shown in Figure 3. Roll the film in half, pull the film out for a certain length and place it in a horizontal position, prop up the open end mechanically or manually, and push the product to the crease. Before that, a transverse seam was left after the last heat seal cutting, and a total of two seams plus a crease do not need to be sealed. Therefore, an L-shaped heat seal cutter is used to press down and heat seal and cut from the connection between the rear of the product and the film. Complete one horizontal seam and one longitudinal seam at a time. It is easy to operate, manual or semi-automatic. It is suitable for packaging products with irregular shapes and large size changes

(2) pillow bag packaging can be used with a single flat film. This method is to use a single flat film, first seal the longitudinal seam into a cylindrical shape, push the product into it, then seal the transverse seam and cut it into a pillow shaped package, or punch and tie both ends into a cylindrical package. The operation process is shown in Figure 4

(3) the double flat film four side sealed packaging is similar to the two end open packaging, which can be completed only by equipping the machine with sealing devices on both sides, as shown in Figure 5

(4) wrap with cylindrical film. If the magnetic attraction is proportional to the volume of particles, we only need to seal and puncture while the cylindrical film is cut. Our company sends professional technicians (certified engineers) to the site for free online debugging, and then carry out thermal shrinkage, as shown in Figure 6. As the residual air inside will expand during thermal contraction after pre sealing with four side sealing method, which makes it difficult for the film to shrink and affects the packaging quality, there are often pricks next to the sealer. During thermal sealing, the pricks prick vent holes on the film, and the small holes often close themselves after thermal contraction

3) open end

tray shrink packaging is a typical example. First, the film is made into a large bag with square bottom, and then the large bag is sleeved on the stacked commodity tray from top to bottom, and then heat shrinkable. As shown in Figure 7, put the tray loaded with products on the conveyor belt and put on the shrink film bag; It is sent to the heat shrink channel by the conveyor belt, and the shrink packaging is completed after passing through the high-tech shrink channel of the heat waterproof experimental machine product. Its main feature is that the products can be firmly packed in a certain number of units, will not be loose during transportation, and can be stacked in the open air

products with large volume can be packed by on-site shrink packaging. Pull the cylindrical film out of the film drum for a certain length, open the open end and wrap it outside the product, seal and cut the upper opening of the film, and then use the portable gun hot air blower to heat all parts of the film outside the product in turn, which can complete the heat shrink packaging of large products. The operation process is shown in Figure 8

(to be continued)

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