The sealing is not strong and easy to open is one of the common faults of the pressure sealer machine, and the sealing here is not strong, specifically referring to the following two situations:

①The sealing part of the packaging bag cannot be sealed;

②Under the pressure of the sealing knife, although the mouth of the bag is sealed, a little harder squeezing or tearing, the sealing will crack again;

The main reasons for the failure are as follows:

(1) The heat sealing temperature is not enough

For composite bags with OPP as the lining, when the total thickness of the bag is 80～90μm, the heat sealing temperature should reach 170～180℃; when the total thickness of the composite bag with PE as the lining is 85～100μm, the temperature is appropriate Control at 180～200℃. As long as the total thickness of the bag is increased, the heat sealing temperature must be increased accordingly.

(2) The heat sealing speed is too fast

The inability to seal is also related to the speed of the sealing machine. If the speed is too fast, the sealing part will be transported to the cold pressing part for cooling treatment before it has time to heat up. Naturally, the heat sealing quality requirements will not be met.

(3) The pressure of the cold-pressed rubber wheel is inappropriate

There is one upper and lower cold-pressed rubber wheel, the pressure between them should be moderate, and only the spring needs to be clamped when adjusting the pressure.

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

The inability to seal the seal is also related to the quality of the heat-sealed film. If the corona treatment of the composite lining is uneven, the effect is not good, and it happens to be at the seal, it will definitely not be able to seal. This situation is rare, but once it occurs, the product must be scrapped. Therefore, in the color printing and packaging industry, the next process is to supervise the previous process. Once a quality problem is discovered, the cause must be analyzed and resolved in time.

(5) The heat-sealed knife surface is uneven

The heat-sealing knife is divided into upper and lower pieces, and usually, thermocouples are installed in them to sense the temperature transfer. There are three screws on the heat-sealing knife. The screw in the middle plays the role of supporting and strengthening the blade. The other two screws are equipped with pressure springs and gaskets, which are mainly used to adjust the pressure of the heat-sealing knife. There are two springs for the upper and lower blades. . The main reason for the uneven surface of the heat-sealing knife is that the middle screw is installed obliquely, not horizontal; or the pressure spring of the upper heat-sealing knife is uneven.

In addition, if there are moisture and dirt in the sealing part, the sealing will be weak.

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