Ultrasonic welding plastic parts half an hour, transducer and welding head feel hot, is how to return a responsibility?

1, loosen the screws on the movable frame cover and take out the transducer kit; 

2, the required ultrasonic mold 

3, the ultrasonic bottom mold (first put the plastic parts into the bottom mold) into the ultrasonic mold (welding head) below