METHOD TO CONTROL PROCESS OF ULTRASONIC SEALING OF PLASTIC CONTAINERS FOR STORING AND PROCESSING OF BLOOD COMPONENTS Russian patent published in 2002 - IPC

FIELD: medical technologies; collecting, storing and processing of blood. SUBSTANCE: according to proposed method, section of polymeric tube close to place of its introduction into container is placed between two flat surfaces one of which is acoustically coupled with source of ultrasonic vibrations and is pressed to make opposite inner surfaces of tube come in contact and then tube is exposed to ultrasonic action to make tube material change into viscoplastic state and form a seam. After placing section of feed polymeric tube between two flat surface, voltage is supplied to winding of electromagnet from ultrasonic generator tuned to operating frequency hinger than natural frequency of mechanical vibrations of ultrasonic system. In process of tube pressing, re-tuning of generator for lower frequency is carried out to bring generator working frequency close to natural resonance frequency of vibration system, electric vibrations are converted into elastic ultrasonic vibrations at coincidence of frequencies of generator and vibration system, and thermal seam is formed and then, by re-tuning of generator, frequency is decreased and ultrasonic action is stopped, but voltage from generator is still supplied to winding of electromagnet to stabilize sealing seam. Rate of change of working frequency of ultrasonic generator within preset range is set depending on type of container to be sealed. EFFECT: provision of reliable sealing of all types of containers, both of foreign and home make.