... 20 KHz ultrasonic transducer device;3. The mould for synchronization function;4. Two motor speed control system;5 ... design;6. The running speed of the sewing machine for ordinary four times, simple operation.function1. Trimming: ... thermoplastic thin films, chemical pieces of plastic, etc.Application examplesSuitable for making lace dress, lace, decorative products, handkerchief, tablecloth, curtain ...