As a new type of carton and carton packaging sealing, hot melt adhesive sealing has partially replaced traditional strapping and tape packaging, carton packaging for various food products, and cartons for wine and dairy products. On the packaging. Due to the advantages of good package quality, beautiful appearance and low cost, the application of hot melt adhesive sealing will become more and more extensive.
Hot melt adhesive sealing advantages
Hot-melt adhesive sealing is the use of a hot melt machine to melt the hot melt into a liquid, which is then sent to the surface of the carton through the throat of the hot melt machine and the spray gun. After the hot melt is cooled, the adhesive is completed. It can meet the requirements of carton sealing, and overcome the defects of the traditional carton sealing form.
Good packaging quality
Transport cartons must be able to withstand temperature and humidity changes and rough handling, but it is difficult to meet this requirement with adhesive tape because of poor adhesive strength, low tensile strength, and poor adhesion to coated or oily paperboard.
The hot melt adhesive has good binding force with the wet product, strong penetration force, physical and chemical bonding effect between the corrugated paper and the linerboard, and the integrated strength of the bonded carton is enhanced, and the carton is not easy to be deformed and cracked. In addition, the hot melt adhesive coating system can apply pressure on key parts of various shapes, such as folding lids in cartons.
Secondly, the adhesive tape has poor low temperature resistance and is easy to open in cold weather in the north; the hot melt adhesive has good low temperature resistance and can withstand low temperatures of -40°C. In addition, the hot melt adhesive has a storage period of up to 2 years, and the storage area is small. There is no special storage requirement. The tape storage period is only half a year. It also requires a certain storage condition, or it will easily deteriorate.
Hot-melt adhesives also provide good anti-theft protection. As the adhesive penetrates into the corrugated medium, any attempt to open the carton tears the fibers. The tape can be cut with a knife, and the contents are removed and sealed again unconsciously.
Beautiful appearance
Nowadays, merchants require packaging to convey products and at the same time, they can also convey product and corporate image through packaging design. Therefore, the fewer factors that hinder appearance, the better. Adhesive tape often obscures images and interferes with the transfer of packaging information. Hot melt adhesives are glued between flaps to provide more room for display.
low cost
The use of hot melt adhesive sealing speed, the entire bonding process only takes 1 to 3 seconds to complete, suitable for mass production, low energy consumption, low cost. The standard corrugated carton hot melt adhesive seal is approximately 32 yuan/1000 cases, which is the middle price of the hot melt adhesive, and the middle price of the tape seal is approximately 120 yuan/1000 cases.
If hot-melt adhesives are used, the addition of glue during processing will not cause a shutdown; the replacement of the tape requires shutdown. Moreover, no partitions may be installed in the box, and the strength of the sealing is greater than the strength of the sealing of the inner partition when the tape is used to seal the box, which can reduce the cost of the partition.
Melt glue selection
The affinity of the hot melt adhesive to different bonded materials is different. In order to make the hot melt adhesive perform better "stickiness", the following factors should be carefully considered in selecting the hot melt adhesive.
colour. Due to the different colors of the adhesive, the color requirements of the hot melt adhesive should be different. If there is no special requirement on the color of the adherend itself, it is recommended to use yellow hot melt adhesive. In general, the yellow hot melt adhesive is more viscous than white.
Bonded surface treatment. The surface treatment of the hot melt adhesive to the adhered material is not as strict as other adhesives, but the dust and oil stains on the surface of the adhered material should also be properly treated so that the hot melt adhesive can better exert the adhesive effect.
Working time. Fast job is a major feature of hot melt adhesives. The working time of hot melt adhesives is generally around 15 seconds. With the wide application of modern production methods, assembly lines, hot melt adhesives require shorter and shorter working time.
Anti-temperature. Hot melt adhesives are sensitive to temperature. When the temperature reaches a certain level, the hot-melt adhesive begins to soften; below a certain temperature, the hot-melt adhesive will become brittle, so the choice of hot-melt adhesive must fully consider the change of the ambient temperature.
viscosity. The tackiness of hot melt adhesives is early tack and late tack. Only the early stickiness and the late stickiness can make the hot melt adhesive and the adherend stable. In the production process of hot melt adhesives, it should be ensured that it has anti-oxidation, anti-halogen, anti-acidity and plasticity.
