We should have seen the mouth bag in our life, the application range is in daily necessities or some jelly bags. It is used in liquid packaging. In order to prevent liquid deterioration, or leakage, so the material and heat sealing requirements are particularly high. Let's introduce the self-supporting vertical suction bag for you:
1、 Selection of composite materials
Due to the high requirements of mechanical properties of materials for vertical bags, multilayer composite films are generally used.
1. Outer layer
The outer layer is the printing material. In addition to the common OPP, there are also high strength and high barrier materials such as pet and PA, which can be selected according to the situation. If it is used to pack dry fruit solid products, BOPP, dull BOPP and other common materials can be selected. If liquid products are packed, pet or PA materials are generally used.
2. Middle layer
The intermediate layer is generally made of high strength and high barrier materials, such as pet, PA, VMPET, aluminum foil, etc. Moreover, RFID requires that the surface tension of the interlayer material should meet the composite requirements, and it must have a good affinity with the adhesive.
3. Inner layer
The inner layer is the heat sealing layer, and PE or CPE, CPP and other materials with strong low temperature heat sealing performance are generally selected. It is required that the surface tension of the composite surface should meet the composite requirements, but the surface tension of the hot surface must be lower than 34mn / m, and it should have good anti pollution ability, antistatic ability and heat sealing property.
2、 Requirements for bag making process
1. Heat sealing temperature
When setting the heat sealing temperature, the following factors should be considered: first, the characteristics of the heat sealing material; second, the thickness of the film; third, the times of hot pressing and the size of the heat sealing area. In general, the same part of the hot pressing times more, the heat sealing temperature can be set lower appropriately.
2. Heat sealing pressure
When heat sealing, proper pressure must be applied to promote the bonding of hot cover materials. However, if the pressure is too high, the molten material will be extruded, which will not only affect the flatness of the bag, fault analysis and troubleshooting, but also affect the heat sealing effect of the bag and reduce the heat sealing strength.
3. Heat sealing time
The heat sealing time is not only related to the heat sealing temperature and pressure, but also to the performance of the heat sealing material and the heating method. The specific operation should be adjusted according to different equipment and materials during the actual test run.
4. Heating mode
There are two kinds of heating methods of heat sealing knife in bag making: one side heating and two sides heating. Obviously, the two side heating mode is more efficient and practical than the unilateral heating mode.
There are many problems in the actual production of vertical bags, but there are mainly two prominent problems: one is the leakage of liquid or gas when filling goods; the other is the uneven shape and asymmetric bottom seal in the process of bag making. Therefore, how to choose the best materials and adopt the best operation mode plays a decisive role in improving the overall quality of the vertical bag.
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.