Vacuum packaging bags are widely used in the flexible packaging industry. In the process, some quality problems will occur more or less. Today, Xi'an vacuum packaging bags manufacturers give a brief introduction to the common quality problems of vacuum packaging bags and their solutions, as follows:
Question 1: Vacuum packaging wrinkles
Cause Analysis:
1. The thickness of the substrate is not uniform, and the film difference is too large.
2. The substrate is unwound.
3. When the amount of glue is too much or insufficient, interlayer sliding will occur; uneven coating will also cause local wrinkles.
4. The adhesive is not dry enough, the residual solvent is too much, the adhesion is small, and the two substrates after the composite are displaced.
5. The composite film composite film receives the roll without cooling or cooling, and the high temperature soft composite film is easy to wrinkle.
6. The tension composite pressure is not set properly.
7. The tension is not properly controlled, and the tension of the loading and winding is not coordinated or matched.
8. Each guide roller is not parallel.
9. The surface of each guide roller is not clean, there is foreign matter sticking, or the surface of the guide roller is not flat, and there are pits, scribes, bumps, and the like.
solution:
1. Replace the qualified film.
2. The position of the film is neglected so that it does not deflect during the transfer.
3. Adjust the amount of glue applied and apply glue evenly.
4, adjust the process parameters, so that the adhesive can be fully dried, reducing the residual amount of solvent.
5. The composite membrane should be fully cooled before rewinding.
6. Adjust the composite pressure.
7. Adjust the unwinding and winding tension so that the tensions of the parts match each other.
8. Adjust the parallelism of each guide roller.
9. Clean the surface of each guide stick and replace the damaged guide stick to ensure that the surface of the guide roller is smooth, smooth and clean.
Question 2: The vacuum packaging bag is sticky
Cause Analysis:
1. During the printing process, the drying speed of the ink is not suitable for the printing speed, so that some of the solvent remains in the printed ink layer, so that the ink layer softens, so that the composite film is also sticky.
2. The adhesive is not completely dried, and the residual solvent gradually penetrates into the ink layer, so that the ink layer is softened and sticky.
3. The plasticizer in the plastic film migrates to the ink layer, thereby softening and tackifying the film.
solution:
1. Adjust the drying speed of the ink according to the actual situation and make it fully dry.
2. Adjust the process parameters to ensure that the adhesive can be fully dried and the residual solvent amount is controlled within the limits.
3. Replace the plastic film.
Question 3: The vacuum packaging bag has "small pockmarks"
Cause Analysis:
1. There are impurities in the adhesive. There is too much dust in the air in the workshop environment. There is also dust in the hot air blown out in the drying tunnel after the glue is applied. The dust adheres to the rubber layer and is sandwiched between the two base films.
2, the two-component reactive adhesive solvent is easily affected by temperature and becomes white and turbid, resulting in an increase in "small pockmarks".
solution:
1. Filter the adhesive; keep the environment clean; keep the rubber bucket and glue tray clean; remove the dust from the hot air with a high mesh filter or other filter material at the air inlet of the drying tunnel.
2, "cloudy white" glue can not be used again.
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