The heat seal is fragile
1. Causes: the heat sealing pressure is too large, the heat sealing time is too long or the heat sealing temperature is too high, and the edge of the heat sealing line is squeezed thin.
Solution: adjust the pressure, temperature and time to appropriate.
2. Cause: poor film strength.
Solution: 1. Choose the film with good strength.
② Blown film can be selected for the inner film of the composite bag, because the strength of the blown film is better than that of the tape casting film.
③ For composite bags used for cooking, the thickness of inner film shall not be less than 0.07mm
3. Cause: the heat sealing line is stressed when it is not cooled.
Solution: avoid lengthening or thinning of heat sealing line.
4. Cause: the heat sealing temperature is too low.
Solution: 1. Increase the heat sealing temperature.
② Increase the heat sealing time.
5. Cause: the heat sealing pressure is too low.
Solution: increase the heat sealing pressure.
Poor heat sealing or low strength
1. The reason is that the corona treatment is excessive, and the thin film produces a new weak interface layer.
Solution: properly reduce the corona treatment intensity.
2. Reason: the film thickness difference is too big.
Solution: choose the film with uniform thickness.
3. Reason: the strength of the film itself is poor.
Solution: choose the film with good strength.
4. Reason: the selected film material is improper.
Solution: according to different uses (such as heavy packaging bags, light packaging bags, liquid packaging bags, etc.), choose different film types and varieties.
5. Cause: improper heat sealing conditions.
Solution: 1. Increase the heating temperature and shorten the heating time.
② Increase the heating temperature and reduce the heat sealing pressure.
6. Reason: the selection of heat sealing machine is not suitable.
Solution: for the heat sealing of heavy packaging bags and folded edge bags with larger thickness, it is better to use double-sided heating heat sealing machine.
(3) uneven heat seal
1. Cause: improper temperature control.
Solution: 1. The temperature of heat sealing tools should be uniform, and the difference should not exceed ± 5 ℃.
② Check: the sensitivity of the temperature controller should not be greater than 5 ℃.
2. Cause: uneven heating pressure
Solution: 1. The heating tool should be parallel to the liner surface, and the contact should be kept clean.
② The thickness error of thin film should be small.
(4) poor openness
1. Cause: the film is not cooled after printing.
Solution: cooling should be sufficient before coiling.
2. Cause: excessive coiling tension.
Solution: 1. Reduce the winding tension.
② The film should be cooled sufficiently before coiling.
3. Cause: both sides of the film are corona treated.
Solution: corona treatment is only applied to printing and composite surface.
4. Cause: poor opening of the film.
Solution: choose the film containing anti adhesion agent.
5. Cause: the cutting line of bag mouth is too close to the heat sealing line.
Solution: the cut-off line should be more than 2-3mm away from the heat sealing line.
6. Cause: poor opening of composite bag.
Solution: 1. Blow molding film is selected for inner film.
② During curing, the oven temperature should not exceed 60 ℃.

③ The film should be cooled sufficiently before bag making.

5. Composite thermal bonding layer
1. Cause: heat seal part of the existence of ink is the main cause of stratification.
Solution: Design in advance before printing to avoid printing ink in the heat seal.
2. Cause: poor heat resistance of ink
Solution: 1. Use ink with good heat resistance.
② Before printing, the film is surface treated to improve the adhesion of the ink.
3. Cause: the temperature difference between inner and outer layers is too big.
Solution: 1. Reduce the heating temperature and reduce the bag making speed.
② Preheat before heat sealing.
(6) ink shedding
1. Cause: there is ink in the heat seal.
Solution: in the heat seal should avoid the existence of ink.
2. Cause of poor heat resistance: ink.
Solution: choose the ink with good heat resistance.
3. Reason: use grid type heat sealing tool.
Solution: 1. Use flat heat sealing tools.
② Paste a piece of PTFE sheet under the heat sealing tool.
4. Reason: for the aluminum foil composite material, even if the surface layer is not softened, the AC agent and printing ink have melted, so the film-like fall off.
Solution: 1. Use heat resistant AC agent and printing ink.
② Reduce the heat sealing temperature and prolong the heat sealing time.
Dongguan Beite packaging materials Co., Ltd. - located in Dongguan City, the world's manufacturing city, is a subsidiary of Beite packaging (China) Co., Ltd., with a plant area of 6000 square meters. It is a flexible packaging enterprise integrating R & D, production and sales. It has a complete set of domestic advanced production equipment, a scientific and humanized management system and a group of experienced technical personnel For backing, to provide customers with quality products and first-class service.
The company produces composite bags, roll film, fruit bags, aluminum foil bags, suction mouth bags, self-supporting bags, zipper bags, anti-static bags, special-shaped bags, etc., which are suitable for the internal and external packaging of food, daily chemicals, electronics, toys, medicine, cosmetics, industrial products and other industries.
We uphold the integrity of cooperation, good quality, good service business philosophy, won the industry's approval, products sold to all over the world; welcome friends from all walks of life to inquire, visit our factory to investigate guidance and business negotiations.