Wrapping Technology (I)

Wrapping is a method of wrapping all or most of the product or the original packaged product with a relatively thin flexible material. Most of the packages are sales packages. The characteristics of the wrap are: the use of materials, easy to operate, can be operated by hand and machine; low, medium and high speed; can adapt to many kinds of different shapes, different characteristics of the product packaging.
First, the wrapping method There are many forms of wrapping, according to the form of wrapping can be divided into two categories: folding wrap and kink wrap; according to the operation can be divided into three categories: manual operation, semi-automatic operation and fully automatic operation.
1. Folding wrapping method This is the most used method in the wrapper and the package is neat and beautiful. The basic method of fold-over wrapping is to cut a length of the length from the roll material, or to cut the material beforehand and stack it in the storage rack. The material is then wrapped around the wrapped article, wrapped in a tube with a lap joint, folded at both ends and sealed. Depending on the nature and shape of the product, the need for surface decoration and mechanization, the position of the seam and the form and direction of the open end fold can be changed.
(1) Both ends of the folding type This method is also called the carton, paper tray package type. Suitable for wrapping products with regular square shape. The basic operation method is as follows: the first wrapping is a cylindrical shape, the seam is generally placed on the bottom surface, and then the short sides of the two ends are folded so that the remaining two sides form a triangle or a trapezoidal corner. Finally, these corners are folded and sealed in turn. The folding sequence is shown in Figure 10-9.

In manual operation, seams can be used for seams, which can be tightly wrapped to make the package surface smooth, as shown in Figure 10-10.

When the machine is operated, due to different working principles, the order of the knuckles and the moving direction of the product are different. As shown in Figure 10-11, for the up and down and horizontal movements, the folding sequence is shown in the arrows.

As shown in Figure 10-12, the horizontal movement, seams on the side, front and back both sides of the pattern are complete, suitable for upright box wrapping. The folding order is (a) and (b). The characteristic of (b) is to fold the short sides of the two ends first, so that the packaged product, especially the multiple products, can be guaranteed to be in a good position. As shown in Fig. 10-13, the final long-edge fold is folded back to the seam, and the heat-sealing or wax-coating can be completed at one time. If aluminum foil or its composite material is used, there is no need to seal it, common small products such as chocolate and milk sugar. The operating sequence is shown in Figure 10-13.

For some thin rectangular products. The inner foils such as chewing gum, chocolate plate sugar and the like are formed by folding the long side flaps all the way to the bottom and the seams, and then the sleeves are printed with a trademark and a pattern.
(2) Side seam angle type This method is also called cigarette wrapping type. When the machine is operated, especially with a high-speed fully automatic wrapping machine, the seams are not tightly placed on the back side as tightly as the manual operations. Therefore, the sealability of the package is poor; on the other hand, the seams affect the integrity of the decorative pattern on the back side. Cigarette packaging is a representative example. The original packaging of ordinary cigarettes is divided into three types: plain paper, hardcover, and cellophane wrapper. The innermost layer is impregnated with pitch paper or crepe paper aluminum foil, and uses six kinds of side-seam folded corners. As shown in Figure 10-14. The folding sequence is shown in Figures 1 to 7. A layer printed with a trademark pattern is generally an outer layer, and five sided breadboards with side seams are used. Finally, seals are placed at the opening. As shown in Figure 10-15. Some products, such as audio tapes, boxed tablets, etc., are also used for the convenience of retail. In the case of multiple wraps, side seams are also used to fold five loaves, as shown in Figure 10-16.

(3) The two-folding style is also called parcel wrapping. It is suitable for wrapping products that are not square in shape, changeable or soft, such as breads and cakes. Folding during wrapping is characterized by the fact that one fold is pressed against the lower edge of the fold, unlike the folds wrapped at both ends. The folds and folds are symmetrical about the top and bottom. The folding sequence in this way is shown in Figure 10-17, 1-4.

(4) Multiple-pleats at both ends This method is suitable for wrapping cylindrical or similar products such as round biscuits, toilet paper rolls, oil felts, drying papers, and large webs. The operation process is: first wrap the packaging material on the product to form a cylinder. Then fold the two ends into many pleats in the circumferential direction, one against the other. Finally, seal the ends with a circular label sheet. As shown in Figure 10-18.

(5) Bevel angle This is the simplest, most economical and smooth method. Its characteristic is that the symmetry axis of the packaged item coincides with the diagonal line of the packaging material, and there is no seam. All the folding angles are concentrated on one surface. Only suitable for wrapping square or rectangular and thinner products. Sometimes a trademark paper is attached to the folding corner, which is beautiful and plays a role in sealing.
(To be continued)