Shaped bag with its shape changeable features have excellent shelf appeal, is the more popular form of packaging in foreign markets. With the improvement of people's quality of life, the current shaped bag has gradually become China's commodity production enterprises to improve brand awareness, increase product selling point of one of the means.

Shaped bag production and processing can be divided into review, typesetting, printing, composite, slitting, bag making, mold punching, pipetting and other steps, the focus of the production and the difficulty lies in the bag making, mold punching process, review, typesetting process there are some issues that deserve special attention, while printing, composite process and other types of flexible packaging products are basically the same.

Below, will be combined with an example, focusing on the review, typesetting and bag making, mold making process to talk about the processing of shaped bags production skills, I hope to throw a brick to attract jade, and colleagues to discuss.

Review and layout

In the shaped bag review, typesetting process, bleeding, the direction of the bag and the number of channels is a key issue that must be focused on control.

1. Bleeding control

Figure 1 shows the design of the shaped bag as shown in Figure 2, the biggest problem is that there is no design bleeding bit, according to such a design produced by the shaped bag in the cutting process will appear “cut more on the loss of content, cut less on the white edges,” the problem, seriously affecting the appearance of the product. Shaped bag bleeding bit is generally 3mm or more than 3mm, so in order to facilitate the production of the design shown in Figure 2 should be re-designed bleeding bit.

2. Selection of the direction of the bag

Out of the bag direction generally have “horizontal” and “vertical” two kinds. Shaped bag front text, pattern left or right in the bag first out is “horizontal”, shaped bag front text, pattern feet or head in the bag first out is “vertical”. The choice of the direction of the bag should take into account the characteristics of the shaped bag, the characteristics of the processing equipment, customer requirements and other factors, the choice of improper will greatly affect the production efficiency, or even lead to no production at all. Figure 1 shows the shaped stand-up pouches should be selected “horizontal out”.

3. Control of the number of channels

The number of channels refers to the layout of the consideration of the transverse can produce a one-time number of shaped bags, which is also a key item of shaped bag layout, layout should take into account the difficulty of processing and production efficiency of the two factors.

Bag making and mold punching

Bag making, mold punching process is a shaped bag molding process, there are two issues worth noting: that is, the design of the sealing knife and the choice of molding.

1. Design of sealing knife

Sealing knife position should be accurate, to coincide with the pattern on the shaped bag, and for the sealing of the straw reserved for the appropriate location and size. If the size of the reserved position at the seal is too large, the seal is not easy to seal, easy to leak the bag; if the size of the reserved position is too small, it is difficult to fit the straw. In determining the size of the sealing place reserved, generally based on the circumference of the straw, if encountered irregular shape of the straw, you can use a soft line around the straw week, in the soft line half the length of the basis of the extra 2 ~ 3mm margin can be.

During the sealing process, care must be taken to keep the gap between the sealing mold and the straw uniform to avoid bag leakage problems due to poor airtightness. If the airtightness of the shaped bag is found to be poor during random inspection, the machine should be stopped in time to check and re-polish the sealing mold. If it is found that the whole side of the bag is not sealed securely, it can be compensated by adding high temperature cloth on the side that is not sealed securely.

2. Selection of molding method

Shaped bag has two main molding methods: in the bag-making machine directly out of the bag, or in the molding machine molding out of the bag.

(1) in the bag-making machine directly out of the bag

The advantages of this molding method is to save time and trouble, relatively economic, and the molding process and sealing process is completed at the same time, there are fewer problems such as “big and small edge”, leakage or sealing the edge of the bag is not secure.

But the disadvantage is that it is difficult to adjust the machine, as long as the design and layout of a slight problem, it will bring a lot of trouble.

In order to bag machine directly out of the bag, you must design the knife mold and will be installed in the fixed sealing knife on the beam. The shape of the knife mold and the shape of the bag to maintain consistency, but also pay attention to a technical problem: according to the characteristics of the shape of the bag to find a few suitable points in the knife mold to make a few small openings (similar to “even point”, shown in Figure 3), the purpose of doing so is to let the bag will not be complete in the bag-making machine cut down, in the rubber roller traction can be through this Under the action of the traction of the rubber roller can be through these “points” will be shaped bag smoothly dragged to the cut bag mouth, and then in the cut bag mouth will be shaped bag completely cut, easy to collect the bag and bundling packaging.

Without these “points”, the shaped bag is easy to fall in the bag making machine causing failure. However, now the new bag-making machine through technological improvements, also has a bag, pressure cut and out of the bag function, but the price is not expensive.

After the mold design, you should also choose the appropriate cutter blade. Cutter blade sharpness and hardness must meet certain requirements, not only to ensure that under the pressure of the beam spring will be cut part of the cut down, but also to ensure that in a long period of time under the action of the pressure of the knife will not occur under the mouth of the volume of the mouth and other issues. Generally a good cutter blade can make 100,000 shaped bags.

In addition, because the knife die in the downward pressure cutting process will produce considerable pressure, so the fixed knife die beam must remain stable and can withstand a certain amount of weight; beam spring deformation must be good to ensure that in the process of deformation can produce a constant pressure; fixed knife die and bear the pressure cutting force of the steel plate must be flat, so that the pressure cutting out of the shaped bag will be smooth and free of burrs.

(2)Molding out the bag on the punching machine

The second type of molding is based on the shape of the shaped bag processing mold, and then in the die machine to complete the molding of the bag.

The advantage of this way is: shaped bag molding quality is better, less burrs, and can be molded at a time more than one shaped bag.

The disadvantages are: mold production costs are high, a shaped bag may need to use several molds, low efficiency; molds can not be shared, the next time the production of other types of shaped bags, the original molds basically can not be used, a big waste; sealing and molding can not be completed at the same time, more time-consuming.

Therefore, this program is only suitable for the production of some temporary, difficult shaped bag workpiece, large quantities of workpiece is not suitable to take this program.