Pinholes or serious tears will be generated at around the edge of the joint between the aluminum foil and the bottle mouth, when the aluminum foil absorb too much hear energy. The contents will penetrate and corrode each layer of the seals in that case, then lead to liquid leakage.

In order to avoid the above problem, we can improve from 4 aspects.

1. Sealing machine power

2. Belt speed

3. Distance from cap to electromagnetic induction head

4. Voltage of sealing machine

Better put the bottles in the middle of the  heads.The appropriate low temperature and low speed can minimize the pinholes and tears. The unstable electric voltage, even the high-power electric appliances oepn/close affect the power of the sealing machine, making the magnetic field intensity change frequently, then resulting in abnormal sealing effect.

Sometimes, The seals from different suppliers ask differnt sealing power. It is caused by different temperature resistance of sealing film PET, and different aluminum foil thickness.

The pulp layer may adhere to the aluminum foil when seal the bottle/jar with large-diameter cover. It can be sloved by increasing the distance between the cap and electromagnetic induction head.