The packaging form of self-supporting bag is widely used in liquid beverage products. Compared with other packaging, self-supporting bag packaging bag is unique. It can stand on the ground without support, and can be taken and placed at any time and anywhere. And the appearance is good-looking, but also conducive to the display of the shelf. There are many kinds of self-supporting bags, such as suction mouth self-supporting bags, zipper self-supporting bags, octahedral sealing self-supporting bags, aluminum foil self-supporting bags, etc?
< production procedures >
1. Preparation: install transverse heat sealing knife, bottom heat sealing knife, strengthen heat sealing knife, and install punching device.
2. Through the film, set EPC, and align the bag edge and pattern.
3. Adjust the bottom heat sealing knife, input the length and size, and align the position and direction of the knife. Adjust the knife with the upper knife as the reference. Check whether the round hole is round. Set the photoelectric sensor.
4. Install the bottom film, adjust to the middle fold. Adjust the bottom film.
5. Adjust the transverse heat seal to make the position of the heat sealing knife and the printing position align.
6. Adjust and strengthen the heat sealing block and make up the pressure at the intersection of the four layers.
7. Adjust the cutter and edge cutting device.
8. Confirm and adjust the bottom drilling position and the bottom heat sealing position. Confirm and adjust the position of transverse heat sealing knife and strengthening heat sealing block. Confirm the heat sealing strength and adjust the heat sealing temperature.
< key points of production >
1. The bottom film tension should not be too high. If the tension is too high, the round hole on the bottom will deform. The general tension is 0.05 ~ 0.2MPa.
2. In the first group, the pressure is higher and the temperature is lower. The second and third groups use normal temperature and pressure.
3. The spring pressure of strengthening heat sealing block is adjusted to zero, which only makes the self weight of heat sealing device work.
4. Generally, the hardness of silica gel plate is 50 ° and that of 70 ° is used when the hot sealing area is small.
5. During heat sealing, the round hole on the bottom surface is called ellipse, which can increase the waiting time by 100 min.
6. The speed of bag making is generally 50 ~ 100 / min.
Treatment of defects in self supporting bag production process
1、 Bag leakage
The leakage of self-supporting bags is mainly due to the selection of composite materials and heat sealing strength.
1. Material selection
The material selection of self-supporting bag is very important to prevent leakage. The purpose is to improve the peel strength between the outer layer and the middle barrier layer, between the barrier layer and the heat seal material, and the heat sealing strength of the bag. Therefore, it is required that the surface tension of the composite surface of the film must be greater than 38dyn / cm; the low-temperature heat sealing performance of the inner layer heat sealing film is better, and the surface tension of the hot cover must be less than 34dyn / cm; in addition, the ink with good connection performance, the adhesive with high solid content and low viscosity, and the organic solvent with high purity should be selected.
2. Heat sealing strength
Low heat sealing strength is also one of the important factors affecting the leakage of self-supporting bags. During heat sealing, the matching relationship among heat sealing temperature, heat sealing pressure and heat sealing time should be adjusted. In particular, we should pay attention to explore the heat sealing temperature of bags with different structures. Due to the different melting points of different types of plastic films, the heat sealing temperature is also different; the heat sealing pressure should not be too large, and the heat sealing time should not be too long, so as to avoid macromolecule degradation, and the heat sealing layer is sheared by the heat sealing knife in the high temperature melting state, so as to reduce the sealing strength. In addition, the four layer sealing position at the bottom of the self-supporting bag is the most critical part, and the heat sealing temperature, heat sealing pressure and heat sealing time can be determined only after the full test and verification.
In the actual production process, the leakage test should be carried out according to the different requirements of the contents. The most simple and practical method is to fill a certain amount of air into the bag, heat seal the bag mouth, put it into the water basin, squeeze different parts of the bag by hand, if there is no bubble escaping, it means that the sealing tightness of the bag is good; otherwise, the temperature and pressure of the heat sealing of the leaking part should be adjusted in time. Self supporting bags containing liquid should be treated more carefully. Squeeze and drop methods can be used to detect whether there is leakage. If a certain amount of water is filled in the bag, the mouth is sealed, and the pressure test method of GB / t1005-1998 is adopted. The drop test method can also refer to the above standards.
2、 Uneven bag shape

Flatness is one of the indicators to measure the appearance quality of packaging bags. In addition to material factors, the flatness of self-supporting bag is also related to heat sealing temperature, heat sealing pressure, heat sealing time and cooling effect. If the heat sealing temperature is too high or the heat sealing pressure is too high and the heat sealing time is too long, the composite film will shrink and deform. Insufficient cooling will result in insufficient setting after heat sealing, which can not eliminate the internal stress and make the bag wrinkle. Therefore, the process parameters should be adjusted and the cooling water circulation system should be ensured to work normally.

3、 Poor symmetry
Symmetry not only affects the appearance of self-supporting bags, but also affects its sealing performance. The most common asymmetry of self-supporting bag is often reflected in the bottom material part. Due to improper control of the bottom material tension, the round hole on the bottom surface will deform or the tension of the main material will not match, resulting in wrinkles, and the heat sealing strength will be reduced. When the bottom hole is deformed, it is necessary to reduce the discharging tension properly, and increase the waiting time for correction during heat sealing, so as to fully heat seal the intersection of the four layers at the bottom of the bag. In addition, the asymmetry of bag shape is also related to photoelectric tracking, discharging, cursor design, rubber roller balance, synchronization of stepping motor or servo motor, etc. This problem should be solved according to different products and different bag making equipment in the specific operation.
Dongguan Beite packaging materials Co., Ltd. is a large-scale company specializing in the production of food grade composite packaging. It is a professional manufacturer of composite packaging bags. It uses new equipment to produce packaging bags and roll films, providing comprehensive, environmental protection and safety packaging services for the market. The company produces composite bags, roll film, fruit bags, aluminum foil bags, suction mouth bags, self-supporting bags, zipper bags, anti-static bags, special-shaped bags, etc., which are suitable for the internal and external packaging of food, daily chemicals, electronics, toys, medicine, cosmetics, industrial products and other industries. We uphold the integrity of cooperation, good quality, good service business philosophy, won the industry's approval, products sold to all over the world; welcome friends from all walks of life to inquire, visit our factory to investigate guidance and business negotiations.