6、 Heat-seal leakage
Leakage is due to the existence of some factors, so that the parts that should be combined by heating and melting are not sealed. There are several reasons for leakage:
A: Insufficient heat-sealing temperature. The heat-sealing temperature required by the same packaging material at different heat-sealing positions is different, the heat-sealing temperature required by different packaging speeds is different, and the heat sealing temperature required by different packaging environment temperatures is also different. The heat-sealing temperature required for the longitudinal and transverse sealing of packaging equipment is different, and the temperature of different parts of the same heat-sealing mold may also be different, which must be considered in packaging. For the heat-sealing equipment, there is still a problem of temperature control accuracy. At present, the temperature control accuracy of domestic packaging equipment is poor. Generally, there is a deviation of 10~C. That is, if the temperature we control is 140%, the temperature in the packaging process is actually 130~150~C. Many companies use random sampling in finished products to check the air tightness, which is not a good method. The most reliable method is to take samples at the lowest temperature point within the range of temperature changes, and the samples should be taken continuously so that the samples can cover all parts of the mold in both vertical and horizontal directions.
B: The sealing part is polluted. In the process of packaging filling, the sealing position of packaging materials is often polluted by the packaging materials. The pollution is generally divided into liquid pollution and dust pollution. The pollution of sealing parts can be solved by improving packaging equipment and using anti-pollution and anti-static heat-sealing materials.
C: Equipment and operation problems. For example, there are foreign matters in the heat-sealing die clamp, the heat-sealing pressure is not enough, and the heat sealing die is not parallel.
D: Packaging materials. For example, there are too many smoothing agents in the thermal sealing layer, which may cause poor thermal sealing.
Post time: Mar-02-2023