Liaoning Unify High Frequency Equipment Co., Ltd.

How to Deal with the Ignition Accident for High Frequency?

During operation, the high frequency plastic welder will transmit 13.56 and 27.12 MHz of high frequency. Under the condition of a certain temperature and pressure, it can bond the PVC plastics through the high frequency oscillation generated by the aluminum alloy mould, so as to achieve the purpose of products packaging. However, in the process of PVC plastic bonding with the high frequency machine, it is easy to cause the ignition accident, resulting in the burning of PVC plastic box, and the damage in the surrounding knife in the upper mould and the insulation board in the lower mould. The ignition of high frequency machine is a discharge phenomenon caused by the friction between the mould and other substances (including dust and impurities in PVC plastic) during high frequency oscillation. Its hazard is a problem that equipment manufacturers and users have been improving and overcoming. At present, there is no effective solution in the packaging industry.

Ⅰ. The reason analysis of the ignition of high frequency machine

1. The dust and black spots left by the arcing of high frequency mould are not treated properly after the mould is ignited;
2. The high frequency upper mould starts to emit high frequency electromechanical current before the upper mould is completely in contact with the lower mould;
3. The insulated material on the surface of the high frequency mould has not been properly treated;
4. The horizontal adjustment of the mould is not enough, which is easy to cause fire and mould damage;
5. In the thermal sealing process, the high frequency current is adjusted to a too-large level, which is easy to cause the super-firing phenomenon of the mould;

6. Impurities or metal substances are mixed in the medium of high frequency processing workpiece
7. The production quality of the capacitor is poor. The mould has burr or edges and corners are too sharp. Also it is likely that the material of the capacitor is too thin and thus tip discharge is caused. As a result, the capacitor plate needs an appropriate thickness;
8. The capacitor and the circuit do not match and thus produce the standing wave phenomenon, resulting in that in some places the voltage is equal to twice the normal working voltage, and in the dielectric breakdown.

Ⅱ. How to deal with the ignition accident during the use of high frequency

1. The horizontal level of the high frequency mould must be well adjusted;
2. The current should be adjusted back to 0.2A every time the new mould is debugged. Then use the homomodulator to slowly adjust the current to the appropriate range;
3. When there is the ignition accident during the use of high frequency, use a clean cloth with alcohol, gasoline or toluene to wipe down dust;
4. Certain insulated materials must be used under the high frequency mould so as to effectively prevent the high frequency re-breakdown of the required welding products;

5. The ignition phenomena of the oscillating barrel in the production process mainly include the arcing of capacitors, high pressure tube socket, among others. The treatment is the same as the capacitor adjustment sheet;
6. The capacitor sheet should not be adjusted too violently in the adjustment process, and the corresponding range should be adjusted slowly. The ignition phenomenon generated in the edge of the capacitor sheet in the production process may be resulted from that the edge of the capacitor sheet is not handled cleanly and the aluminum plate has burr. It needs to be polished with the abrasive paper.

Ⅲ. How to prevent the ignition accident during the use of high frequency

1. In the production process of high frequency, it is necessary to clean the oscillating barrel often, which only needs to be blown by the air compressor.
2. The ignition accident during the use of high frequency can not be avoided, because it adopts the principle of electromagnetic wave. We can only lower the frequency of ignition down to the lowest point. It is closely connected with the material. If the material is low-quality, the possibility of ignition is high;
3. The stability of high frequency current is very important in the application process of high frequency fusing machine. The high frequency synchronous fusing machine with the unstable current will frequently suffer from the ignition phenomenon in the production process.

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