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 of the bag cannot be sealed; 2 Under the pressure of the sealing knife, although the bag is sealed, it is squeezed slightly. Or tearing 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, and the quality of such bag sealing is still unsatisfactory, because the contents are squeezed during storage and transportation. It is easy to miss. This situation often occurs when the composite lining is OPP and blown PE.
The main causes of the first failure of the continuous sealing machine are as follows.
(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 the heat seal quality requirement will not be achieved.
(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 in 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. In short, to solve the problem of the first type of sealing is not strong, generally can properly increase the heat sealing temperature, and then reduce the heat sealing speed, while increasing the pressure of the cold pressure rubber wheel.
The main reasons for the failure of the second seal of the continuous sealing machine are as follows.
(1) The heat sealing temperature is not enough
Simply raise the heat seal temperature to solve the problem.
(2) The surface of the heat sealing knife is not flat enough
The heat sealing knife is divided into two upper and lower pieces, usually a thermocouple is installed therein to sense the temperature transfer. There are three screws on the heat sealing knife. The middle screw acts as a support and reinforcement blade. The other two screws are equipped with pressure springs and washers. They are mainly used to adjust the pressure of the heat sealing knife. The upper and lower blades each have two springs. . The main reason for the unevenness of the heat sealing knife surface is that the intermediate screw is inclined, not horizontal; or the pressure spring pressure of the upper heat sealing knife is uneven.
The solution is to recalibrate the position of the intermediate screw so that it is level. If the upper and lower heat-sealing knives are unbalanced, it should be realized by adjusting the pressure springs, and the adjustment can be moderate. When the spring is retracted, the heat seal knife will fall down; when the spring of the lower blade is tightened upward, the heat seal knife will move upward.
(3) Uneven pressure of cold-pressed rubber wheel
Uneven pressure of the cold-pressed rubber wheel will also cause such a seal to be insecure, and the solution is similar to the first case.
There are two main reasons for the failure of the seal of the third continuous sealer.
(1) Uneven pressure of heat sealing knife or uneven pressure of cold pressing knife
The adjustments on the heat seal knife and the cold press knife are identical.
(2) The surface of the heat sealing knife is not flat enough
