Suction nozzle bag has the characteristics of easy to dump, derive the internal goods, open and closed, can be repeated in the field of liquid and solid, more health than zipper bag, than bottled performance-to-price ratio is higher, therefore developed rapidly and become popular in the market of bag type, often used in beverage, detergent, milk, hot pepper sauce, jelly and other products packaging.
Suction nozzle freestanding bag in the actual production of more problems, but there are mainly two prominent problems: one is the leakage of liquid or air leakage when loaded goods, the other is the bag in the process of bag making is not smooth and the bottom seal is asymmetric. Today, we analyze the material selection and process requirements of the nozzle bag, hoping to improve the overall quality of the nozzle bag.
First, the selection of composite materials
The common suction bag on the market is generally composed of three or more layers of film composite, including the outer layer, the middle layer and the inner layer.
The outer layer is printed material. At present, the commonly used vertical packaging printing materials in the market are cut from ordinary OPP, and PET, PA and other high strength, high barrier materials, can be selected according to the situation. Common materials such as BOPP and dull BOPP can be used to package dried fruit solid products. If liquid products are packaged, PET or PA materials are generally used.
The intermediate layer is generally made of high strength and high barrier materials, such as PET, PA, VMPET, aluminum foil, etc. Moreover, RFID requires the surface tension of the sandwich material to meet the composite requirements, and must have a good affinity with the adhesive.
The inner layer is the thermal sealing layer, which is generally made of PE, CPE, CPP and other materials with strong low temperature thermal sealing performance. The surface tension of the composite surface should meet the composite requirements, and it should have good anti-pollution ability, anti-static ability and heat sealing ability.
Second, the requirements of bag making process
Nozzle bag production is a relatively complex process, including composite, heat sealing, curing and other processes, each process needs to be strictly controlled.
1. The printing
The nozzle bag needs to be heat sealed, so the ink at the nozzle position must use high temperature resistant ink, when necessary, need to increase the curing agent, to enhance the sealing of the nozzle position.
It should be noted that the pressure nozzle is generally not matte oil printing. Because there are differences in the temperature resistance of some domestic dumb oil, many dumb oil in the heat seal under high temperature and high pressure, easy to reverse sticking. At the same time, the heat sealing knife of the general manual pressure nozzle has no sticking high temperature cloth, and the backsticking of the dumb oil is easy to accumulate on the pressure nozzle sealing knife.
2. Composite
Composite can not use ordinary glue, need suitable for the nozzle high temperature glue. For the suction bag that needs high temperature cooking, the glue must be the glue of high temperature cooking level.
Once the suction nozzle is added to the bag, under the same cooking conditions, it is likely that due to unreasonable pressure relief or insufficient pressure retention during the cooking process, the bag will expand at the combination position of the bag body and the suction nozzle, resulting in bag breakage, because the broken bag is mainly concentrated in the weakest position of the soft and hard combination position. Therefore, for the high temperature cooking bag with suction nozzle, the production needs to be more careful.
3. Heat sealing
The following factors should be considered in setting the heat sealing temperature: the characteristics of the heat sealing material; Second, film thickness; Three, hot stamping times and heat sealing area size. Under normal circumstances, when the same part of the hot pressing times, the heat sealing temperature can be set to a lower.
Appropriate pressure must be applied during heat sealing to promote bonding of the thermal covering material. However, if the pressure is too high, the melted material will be squeezed out, which will not only affect the analysis and elimination of the flatness fault of the bag, but also affect the heat sealing effect of the bag and reduce the heat sealing strength.
The heat sealing time is not only related to the heat sealing temperature and pressure, but also related to the properties of heat sealing materials, heating methods and other factors. The specific operation should be adjusted according to the equipment and materials used during commissioning.
