1. Drop test, the cause of package damage? Cause: the packaging bag sometimes has a lower heat sealing strength when the heat sealing temperature is low, but it can also meet the requirements of customers, but the packaging bag is not damaged during the drop test. In the case of higher heat sealing temperature, although the heat sealing strength is higher, the packaging bag is damaged during drop test. This phenomenon shows that when the heat sealing temperature is high, under the action of the pressure of the heat sealing knife, the inner PE film bearing the function of heat sealing becomes thin and brittle due to high temperature melting and extrusion, which leads to damage during drop test. Solution: in the bag making process, adjust the appropriate heat sealing temperature and pressure. In order to produce products with excellent comprehensive performance.
2. How to deal with brittle sealing and brittle fracture? Reasons: (1) the heat sealing temperature is too high. (2) Too much pressure. (3) The heat sealing time is too long. (4) The edge of the upper sealer is too sharp or the PTFE coated is damaged. (5) The silicone rubber at the bottom seal is very hard. (6) In the process of compounding and curing, a part of adhesive penetrates into the film. Because of the penetration of adhesive, the toughness (impact resistance) of the substrate decreases and the brittleness increases. (7) After cooling and placing, the heat sealing strength of the plastic composite packaging bag increases, and at the same time, it tends to become brittle. Solutions: (1) according to the heat sealing characteristics of the inner seal material, select the appropriate processing temperature, pressure and heat sealing time. (2) The surface state of the upper heat sealing knife is improved to make the surface of the sealer smooth. (3) It is well covered with polytetrafluoroethylene cloth. (4) Choose the appropriate hardness of silicone rubber pad.
3. What to do if there is static electricity at the sealing part? Solution: during secondary processing, 3% sanitary antistatic agent can be added into the inner PE film to avoid such problems. Therefore, when receiving orders from customers, flexible packaging enterprises should fully understand the characteristics of customers' products and automatic filling production line, so as to have a definite target and better meet the requirements of customers. 4. How to deal with the warpage of the bag after heat sealing? Reasons: (1) the thickness of the composite film is not consistent. (2) The heat sealing temperature is too high or the heat sealing time is too long. (3) In the longitudinal heat sealing knife part, the running track of the composite film is not straight. (4) Insufficient cooling. (5) The ripening time is not enough. (6) The heat resistance of the surface substrate film is poor. (7) In the composite process, the tension matching control of composite substrate is improper, which leads to the residual stress after aging, especially when the thickness of composite film is thin. Solution: (1) adjust the tension of floating roller. (2) The inner sealing substrate with low temperature heat sealing property is selected. (3) Adjust the heat sealing temperature to the appropriate temperature. (4) Cool well. (5) Fully mature. (6) Re select the surface substrate film. (7) Adjust the tension of each part of the composite processing equipment to make the shrinkage ratio of the two composite substrates equal as much as possible.
5. Poor heat sealing strength? Poor heat sealing strength is the most common difficult problem in bag making process. Reasons: (1) the influence of heat sealing materials, different types of heat sealing materials, heat sealing strength is different, such as PP, PE, EVA heat sealing strength is not consistent; the same film with different polymerization methods, heat sealing strength is different; the thickness and uniformity of materials also affect the heat sealing strength; different processing methods of heat sealing layer, such as blow molding, tape casting film, etc., all affect the heat sealing strength. When the film is stored for a long time, the precipitates increase and the heat sealing strength is poor after corona treatment. The hygroscopic material absorbs moisture, the thermal surface delamination, and the peel strength decreases. (2) The influence of composite film processing technology on printing ink temperature resistance is poor or the additives in the ink are not appropriate. Under the high temperature of bag making, the printing layer will peel off and the heat sealing strength will decrease. The heat sealing edge should be designed without pattern as far as possible. The choice of adhesive is also very important in the composite process. The reasonable parameters such as the ratio of adhesive and viscosity will affect the sealing strength. High or medium amount of carboxyl groups is not conducive to the formation of coating materials at high surface temperature. (3) Due to the influence of bag making process, the edge sealing cooling after hot sealing is not enough, the shape is not enough, the internal stress can not be eliminated, and the strength and appearance are affected. Therefore, timely inspection should be carried out to strengthen the cooling water circulation system. The more times of heat sealing, the higher the heat sealing strength. The number of longitudinal heat sealing depends on the ratio of the effective length of the longitudinal welding knife and the length of the bag, and the number of the transverse heat sealing devices is determined by the combination number of the transverse heat sealing devices. Good heat sealing requires at least two times of heat sealing.
Reasons: (1) material factor. For example, Pt, NY and other hygroscopic materials are easy to absorb moisture during storage, and bubbles and gas spots are easy to be produced when making bags at high temperature. In addition, because the composite adhesive is not fully cured, it is not heat resistant and has poor peel strength when heat sealing at high temperature, and it is easy to delamination and produce gas spots. (2) It is easy to produce gas spots when the hot sealing edge is wide. The pressure should be adjusted and the gap should be enlarged to squeeze out the air entrapment. When the film moves, air will be caught if there is fluctuation. Before feeding, the clamping plate should be properly clamped before feeding. (3) Improper bag making control, such as silicone rubber plate deformation for a long time, high temperature cloth damage, dirt on the heat sealing knife, etc. If the process parameters such as bag making speed, temperature and pressure are not appropriate and inconsistent, air spots will also occur. 7. What if the film length is insufficient and the width deviation is too large? Cause: This is due to the wrong winding count or the insufficient length of the cut film, as well as the incorrect positioning of the equipment. In order to meet the needs of users to get a certain length of film, under normal circumstances, the operator can get the winding length from the data display on the winder. However, the film is often broken and part of the film on the surface of the large axis film roll is often cut. If the length is calculated and matched according to the marked length, and it is found that the length is not enough and cannot be spliced at last, the whole vehicle products can not be genuine products, especially the slitter whose width is more than 1 m, which will cause greater economic loss. Solution: in order to avoid this kind of situation, the length of the large axis film roll with the same model, specification and process should have a certain corresponding relationship with the coil diameter. As long as the measured diameter data is compared with the winding length after the machine is put on the machine, we can roughly know whether the coil length meets the requirements. If the difference between the two is large, attention should be paid to the splicing length when cutting, so as to avoid the length difference The occurrence of foot phenomenon.
Dongguan Beite packaging materials Co., Ltd. - located in Dongguan City, a world famous manufacturing city, is a subsidiary company of Beite packaging (China) Co., Ltd
With an area of 6000 square meters, it is a flexible packaging enterprise integrating R & D, production and sales. It has a complete set of advanced production equipment in China
We provide customers with high-quality products and first-class service with the support of the humanized management system and a group of experienced technical personnel.
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 food, daily chemicals, and other special-shaped bags
Electronic, toys, medicine, cosmetics, industrial products and other industries of internal and external packaging.
We uphold the integrity of cooperation, good quality, thoughtful service business philosophy, the industry's recognition, products sold all over the world; welcome to call friends from all walks of life
Consulting, visiting our factory for investigation and guidance and business negotiation.