1. Insufficient heat seal measurement
Usually, when the total thickness of the composite bags with OPP as lining is 80-90 micron, the heat sealing temperature should reach 170-180 C. When the total thickness of the composite bags with PE as lining is 85-100 micron, the temperature should be controlled 180-200 C. As long as the total thickness of bagging increases, the heat sealing temperature must be increased accordingly.
2. The speed of heat sealing is too fast.
Not sealing is also related to the speed of the sealing machine. If the speed is too fast, the sealing area is transferred to the cold pressing area by the traction roll before it can be heated, which naturally fails to meet the quality requirements of the heat sealing.
3. Pressure of cold-pressed rubber wheel is not appropriate
The pressure between the cold-pressed rubber wheels should be moderate, only the spring can be clamped when the pressure is adjusted.
4. The quality of heat-sealed film has some problems.
The seal of express envelope is not on the top, which is also related to the quality of heat-sealed film. If the corona solution of synthetic lining is not symmetrical, the effect is not good, just emerges at the seal, it is sure that it can not be sealed. This situation is rare, but once it emerges, the goods must be scrapped. Because the undertaking of color printing packaging is to monitor the preceding preceding preceding preceding preceding preceding preceding preceding, once quality problems are discovered, it is necessary to synthesize the reasons in time deal with them. If there is moisture dirt in the seal, the seal will not be firmly sealed.