These two small details make the aluminum foil bag never crack again.

In the current market, packaging bags have become one of the necessities for sales. Aluminum foil bags are widely used in food, medicine, cosmetics and other fields to avoid light and retain fragrance. However, the aluminum foil bag may face the problem of cracking, affecting the use effect. Today, we analyze the factors affecting the heat sealing strength of aluminum foil packaging bags. I hope I can bring you more thinking.

There are mainly 6 factors that affect the heat sealing strength of aluminum foil bags.

1, raw and auxiliary materials - the original aluminum foil is the carrier of the bonding layer, and its quality has a deep impact on the heat sealing strength of the product. On the one hand, the surface of the original aluminum foil is greasy, which will weaken the adhesion between the adhesive and the original aluminum foil. On the other hand, the heat sealing strength is also affected by the metal composition of the original aluminum foil and the insufficient surface luminosity. Therefore, the quality of the original aluminum foil should be strictly good.

2, adhesive - adhesive is a special substance containing solvents, it is coated on the dark side of the original aluminum foil under certain process conditions, after drying to form a bonding layer, the heat sealing strength of the product plays a decisive role.

3, the production process - under the control of certain process parameters, the adhesive is coated on the surface of the original aluminum foil to form a film, and the quality of the film will directly affect the heat sealing strength of the product. The more important parameter is the coating speed. If the coating speed is too fast and the drying temperature is too high, the solvent on the surface of the coating film will evaporate too quickly, resulting in the residual solvent in the film, and the drying of the coating film is not sufficient, which will affect the heat sealing strength of the product.

4, heat sealing temperature - heat sealing temperature is an important factor affecting the strength of heat sealing. If the temperature is too high, the bond between the adhesive layer and the pvc film is not strong. If the temperature is too high, the medicine will be affected. Therefore, the reasonable heat sealing temperature is generally between 150 ° C and 160 ° C.

5, heat sealing pressure - In order to achieve the ideal heat sealing strength, you need to set a certain heat sealing pressure. If the pressure is insufficient, the adhesive layer of the aluminum foil bag product cannot be fully bonded with the pvc film for heat sealing, so a good heat sealing effect cannot be achieved. Therefore, the national standard stipulates that the heat seal pressure is 0.20.2×10Pa.

6, heat sealing time - heat sealing time will also affect the heat sealing strength. Under normal circumstances, under the same heat sealing temperature and pressure, a longer heat sealing time can make the heat sealing part sealed more firmly and perfect. It can better achieve the expected heat sealing strength. If the heat sealing time is too short, the heat sealing between the adhesive layer and the pvc film will be insufficient. For this reason, the national standard stipulates that the scientific heat sealing time is 1s.

Therefore, the different packaging materials used in the production of aluminum foil bags require different heat sealing parameters in actual production, so it is necessary to adjust the heat sealing parameters reliably according to the actual production needs and product packaging performance requirements. It should also be noted that under different heat sealing pressure, time and temperature, other heat sealing parameters that can meet the standard are not the same, and should be adjusted according to the actual situation to ensure the heat sealing strength and quality of the aluminum foil bag.

The cooling process of the aluminum foil bag after heat sealing should also be noted. When the weld that has just melted the heat seal is formed at a lower temperature, the heat seal strength of the aluminum foil bag may be reduced due to poor cooling, and the appearance of the weld will be affected, resulting in unqualified products. Generally, poor cooling of aluminum foil bags may be caused by insufficient heat sealing pressure, poor cooling water circulation, too high water temperature or not cooling in time.

In addition, the products that need to be contained in the aluminum foil bag will also affect the heat sealing strength of the aluminum foil bag. For example, packaging fine powder products with aluminum foil bags, it is easy to stick the sealing of aluminum foil bags when loading. At this time, it is necessary to reasonably adjust the thickness of the packaging materials and inner materials of the aluminum foil bag according to the products to be packaged, in order to ensure and improve the heat sealing strength of the aluminum foil bag.