What Is The Reason Why The Sealing Machine Is Not Tight?

Sealing is not one of the common failures of the continuous sealing machine. The sealing is not strong. There are three layers of meaning: 1 The sealing machine of the bag cannot be sealed; 2 Under the pressure of the sealing knife, although the bag is sealed, it is squeezed slightly or Peeling and peeling, the seal will be cracked again; 3 When the peeling test is carried out on the sealing part, half of the sealing is firm and half separated. The quality of the sealing of the bag is still unsatisfactory, because the contents are squeezed during storage and transportation. Easy to miss. This situation often occurs when the composite lining is OPP and blown PE.

The main causes of this failure are the following.

(1) The heat sealing temperature is not enough

Under normal circumstances, the composite bag with OPP as the lining, when the total thickness of the bag is 80-90μm, the heat sealing temperature should reach 170-180 °C; the total thickness of the composite bag with PE as the lining is 85-100μm. When the temperature is controlled, it is controlled at 180 to 200 °C. As long as the total thickness of the bag is increased, the heat sealing temperature must be increased accordingly.

(2) Heat sealing speed is too fast

Sealing is not related to the speed of the sealing machine. If the speed is too fast, the seal will be transferred to the cold pressure for cooling in the future, and naturally it will not meet the heat seal quality requirements.

(3) The pressure of the cold pressure rubber wheel is not suitable

There is one on each of the cold-pressing rubber wheels, and the pressure between them should be moderate. When adjusting the pressure, only the spring should be clamped.

(4) There is a problem with the quality of the heat-sealed film

Sealing is not related to the quality of the heat-sealing film. If the corona treatment of the composite lining is not uniform, the effect is not good, and it appears at the sealing place, and it is certainly impossible to seal. This situation is rare, but once it appears, the product is bound to be scrapped. Therefore, in the color printing and packaging industry, it is the next process of supervision of the next process. Once the quality problem is discovered, the cause must be analyzed and solved in time.

If there is moisture or dirt in the seal, it will also cause the seal to be weak.