With the improvement of living standards, packaging bags can be seen everywhere in daily life, including various clothing packaging bags, electronic packaging, industrial product packaging bags, aluminum foil packaging bags, etc. A good packaging bag also passes production procedures and strict standards. So what problems will you encounter in the process of manufacturing packaging bags? How should we solve it? Let’s share with you the Zhitu packaging below!

packaging bagWrinkle

1. The thickness of the substrate is uneven and the thickness of the film is too different.

2. The unwinding of the base material is skewed.

3. When the amount of glue applied is too much or insufficient, interlayer sliding will occur; uneven glue application can also cause local wrinkles.

4. The adhesive is not fully dried, there is too much residual solvent, the bonding force is small, and the two base materials are displaced after compounding.

5. The composite film is rolled up directly without cooling or if cooling is not possible. High-temperature and soft composite films are prone to wrinkles.

6. The tension and compound pressure settings are improper.

7. Improper tension control, uncoordinated and mismatched unwinding and rewinding tensions.

8. Each guide roller is not parallel.

9. The surface of each guide roller is unclean, with foreign matter stuck on it, or the surface of the guide roller is uneven, with pits, scratches, bruises, etc.

Solution

1. Replace the film with qualified quality.

2. Adjust the position of the film so that it does not deflect during transportation.

3. Adjust the amount of glue applied and apply glue evenly.

4. Adjust the process parameters so that the adhesive can be fully dried and reduce the residual amount of solvent.

5. The composite film should be sufficiently cooled before being rolled up.

6. Regulate compound pressure.

7. Adjust the unwinding and rewinding tensions so that the tensions of each part match each other.

8. Adjust the parallelism of each guide roller.

9. Clean the surface of each guide roller and replace the damaged guide roller to ensure that the surface of the guide roller is flat, smooth and clean.

Aluminizedpackaging bagmottled

1. Improper selection of adhesive. Ordinary adhesives have poor affinity for the aluminum plating layer and poor coating performance. If the coating is uneven, mottled phenomena will occur.

2. There is a lot of residual solvent in the glue. After the printing film is combined, the ink layer is moistened by the residual solvent in the glue and mottled phenomena may occur. 3. The covering power of the ink is insufficient. Especially for light-colored inks, light passes through the ink layer and is reflected back by the aluminum layer, causing mottled results.

4. The amount of glue applied is insufficient or uneven, and there are bubbles in the composite film.

Solution

1. Use special adhesive for aluminized film.

2. Properly increase the drying temperature of the drying tunnel, or appropriately reduce the composite linear speed. Make sure the adhesive can dry sufficiently.

3. Choose ink with strong hiding power or thickened ink layer.

4. Appropriately increase the amount of adhesive applied, and check the condition of the rubber pressure roller to ensure uniform glue application.

The packaging bag is sticky

1. During the printing process of packaging bags, the drying speed of the ink is not suitable for the printing speed, resulting in part of the solvent still remaining in the printed ink layer, softening the ink layer, and making the composite film sticky.

2. The adhesive is not completely dried, and the residual solvent gradually penetrates into the ink layer, making the ink layer soften and sticky.

3. The plasticizer in the plastic film moves to the ink layer, making the film soft and sticky.

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 amount of residual solvent is controlled to a minimum.

3. Replace plastic film

The packaging bag has "small pits"

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 of the drying tunnel after gluing. The dust sticks to the adhesive layer and is sandwiched between the two base films during lamination.

2. The two-component reactive adhesive solvent is easily affected by temperature and turns white and turbid, resulting in an increase in "small pits".

Solution

1. Filter the adhesive; keep the environment clean; keep the glue bucket and glue tray clean; use a high-mesh filter or other filter materials at the air inlet of the drying tunnel to remove dust from the hot air.

2. "turbid white" glue agent cannot be used again.

The above is what the editor of Zhitu shared with youpackaging bagCommon problems and solutions, pay attention to Zhitu Packaging Bags for more information!