As a new type of packaging and sealing form, hot melt adhesive sealing has partially replaced the traditional binding packaging and tape packaging, and has been applied to the packaging of various food cartons and the packaging of wine, dairy products and other products. Due to the advantages of good packaging quality, beautiful appearance and low cost, the application of hot-melt adhesive seal box will be more and more extensive.
Advantages of hot melt sealing box
The hot-melt adhesive sealing box is to melt the hot-melt adhesive into liquid by using the hot-melt machine, and then send it to the surface of the carton through the throat and spray gun of the hot-melt machine, and the hot-melt adhesive will complete the bonding after cooling. It can meet the requirements of carton sealing and overcome the defects of the traditional form of carton sealing.
Good packaging quality
Transport cartons must be able to withstand temperature, humidity changes and rough loading and unloading, but it is difficult to meet this requirement by using adhesive tape because of its poor bonding strength, small tensile strength, and poor adhesion to coated or oily cardboard.
The hot-melt adhesive has a good binding force and strong permeability with wet materials. It plays a physical and chemical bonding role between corrugated paper and liner board at the same time. After bonding, the overall strength of the carton is enhanced, and the carton is not easy to deform and crack. In addition, the hot-melt adhesive coating system can press the adhesive on the key parts of various shapes, such as the folding cover of the carton.
Secondly, the low temperature resistance of the adhesive tape is poor, which is easy to be opened in the cold climate in the north; the hot melt adhesive has good low temperature resistance, which can withstand - 40 ℃. Moreover, the storage period of hot melt adhesive is up to 2 years, the storage area is small, and there is no special requirement for storage; while the storage period of adhesive tape is only half a year, and certain storage conditions are also required, otherwise it is easy to deteriorate.
Hot melt adhesive also provides a good anti-theft function, as the adhesive penetrates into the corrugated box, any attempt to open the carton will tear the fiber. The tape can be cut with a knife, and the contents can be removed unconsciously and sealed again.
Nowadays, the business requires that the packaging can convey the product and company image through the design of packaging pattern and appearance while delivering the goods. Therefore, the less factors that hinder the appearance, the better. The adhesive tape often blocks the image and interferes with the transmission of packaging information, while the hot-melt adhesive is glued between the folding wings, which can provide a larger display space.
Using hot-melt adhesive to seal the box is fast, the whole bonding process can be completed in 1-3 seconds. It is suitable for mass production, with less energy consumption and low cost. The sealing cost of standard corrugated box hot melt adhesive is about 32 yuan / 1000 cases, which is the middle price of hot melt adhesive, while the middle price of tape sealing is about 120 yuan / 1000 cases.
If hot-melt adhesive is used, adding adhesive during processing will not cause shutdown, while replacing adhesive tape requires shutdown. Moreover, the box may not be equipped with partition board, and the sealing strength of the box is greater than that of the box with partition board when the rubber belt is used to seal the box, which can reduce the cost of the partition board.
Choice of hot melt adhesive
In order to make the hot-melt adhesive play a better role in "Stickiness", the following factors should be considered carefully when choosing the hot-melt adhesive.
Color. Because the color of the adhesive is different, the color requirements of the hot melt adhesive should be different. If there is no special requirement for the color of the adhesive, yellow hot melt adhesive is recommended. Generally speaking, yellow hot melt adhesive is better than white adhesive.
Surface treatment of the adherend. The surface treatment of hot-melt adhesive is not as strict as that of other adhesives, but the dust and oil stain on the surface of the adhesive should also be properly treated to make the hot-melt adhesive play a better role in bonding.
Operation time. Fast operation is a major feature of hot melt adhesive. The operation time of hot-melt adhesive is generally about 15 seconds. With the wide application of modern production mode assembly line, the operation time of hot-melt adhesive is required to be shorter and shorter.
Temperature resistance. Hot melt adhesive is sensitive to temperature. When the temperature reaches a certain degree, the hot-melt adhesive begins to soften; when the temperature is lower than a certain degree, the hot-melt adhesive will become brittle, so the selection of hot-melt adhesive must fully consider the environmental temperature change.
Viscosity. The viscosity of hot melt adhesive can be divided into early viscosity and late viscosity. Only when the early viscosity is consistent with the later viscosity can the hot melt adhesive keep stable with the adherend. In the production process of hot melt adhesive, it should be guaranteed that it has the properties of anti oxygen, anti halogen, anti acid and alkali, and plasticizing.