1.Application Princple
Ultrasonic is a vibration mechanical wave which frequency is more than 20000Hz, with high frequency, good directionality, high penetrating power and large tension and other functions. It will produce violent forced oscillation and generate orientation and heat when ultrasonic is spread to the substances. Ultrasonic role in human skin will strengthen the skin blood circulation, promote metabolism, improve skin, promote the permeability of nutrients and drugs or skin or mucous membrane by active substances and penetrate the skin hairdressing purpose. The mechanical action cause cell membranes, enhance the metabolism of vibration and permeability, improve blood and lymph circulation, and improve tissue regeneration, soft tissue. The main role in chemical polymerization reaction reflected reconciliation together. Performance of polymerization can knit group of damage with strong regeneration. Depolymerization reaction to macromolecular viscosity, in ultrasonic depolymerization drugs. Drugs to stick scheduling drop; increase the permeability can absorb the drug efficacy.
Ultrasonic on the human organism has a mechanical effect, thermal effect and chemical effect. Ultrasonic hairdressing apparatus using ultrasonic three effects in the human facial treatment to achieve cosmetic purposes.
Mechanical effect: Ultrasonic with high power and energy on the face can make skin cell vibrate and cause micro massage effect , and change the cell volume ,thus ,to improve the local blood and lymph circulation , enhance the lymph and permeability, improve the cell metabolism and regeneration ability of organization, soften the organization, stimulate the nerve cell functions, system and make skin gloss and stretch.
Thermal effect: Through thermal effect of ultrasonic can improve the skin’s surface, make skin blood circulation , and increase speed of skin cells , reduce neural excitability ,play a rile in pain ,muscle spasm .Ultrasonic within the heat is heat , from 72% to 82% of blood removed from the active area , 18% to 21% by heat conduction and spread to adjacent tissues ,therefore ,the patient feels no heat .
Chemical effect: Ultrasonic can strengthen catalytic ability; accelerate the metabolism of skin cells, so that the direction of organizational changes to the alkaline pH values and the pain associated with acidosis. Ultrasonic can improve cell membrane nutrients and drugs, which depolymerization skin absorbs nutrition, beneficial to the drugs through the bacteria, improve the sterilization ability
Chip type transducers are mainly used for soft thrombus, beauty, thin face or skin
Removal of cellulite type transducers are used for abdominal such as anti-cellulite, play a role in weight loss .
2、Frequently Asked Questions
A: How to distinguish positive (+) and negative (-) electrodes of transducer?
The electrode located between the two piezoelectric chips is positive；
B: How to connect wires?
Must re-wire around hole, then soldering, avoid lap welding
C: How to choose suitable wire to connect transducer?
Using sufficient soft silicone around 1.2 square wire diameter
D: How to insulate and test transducer?
Using heat shrinkable tube and silicone to seal and coat exposed wires and welding parts on the electrodes
E: How to test if transducer has been insulated?
Using a megohmmeter around 1500V to test the insulation impedance of the positive and negative electrodes; required greater than 50MΩ, except for high humidity environments.
F: What’s the meaning of the parameters of transducer?
A: Free capacitance CT=C0+C1，”C0” refer to the static capacitance, “C1” for the dynamic capacitance; “Dt” for the dielectric loss; “fs” for the series resonant frequency, “fp” for parallel resonant frequency and the frequency bandwidth “fsp” = fp-fs; bandwidth “f12” = f2-f1, “f1” and “f2” respectively corresponding to the left and right point of the half-power bandwidth; “R1” refers to the dynamic impedance; “L1” for the dynamic inductance; “Zr” or “Zmin” for the parallel resonant impedance; “Zmax” for the series resonant impedance; “Qm” for the mechanical quality factor; “Keff” for the coupling coefficient.
G: The difference between before and after bonding stainless steel cap.
The parameters is major before bonding stainless steel ,stainless steel cap is as load , the related parameters are shifted when test small signal ,especially the frequency and impedance . So still based on parameters before bonding when working in high electric filed
H: What’s the definition of the power of transducer?
Ultrasonic beauty transducer is generally rated average power. It’s defined as the maximum input power upon resonant frequency.
I: The difference between ultrasonic sliming transducer and cleaning transducer:
Cleaning transducer is generally used with a lot of a parallel; the actual input power is much lower than the rated power. And ultrasonic sound can load easily absorbed water, the heat generated during continuous low and stable; but slimming transducer, usually a single oscillator in the air long dry vibration, high input power, and load absorption low, easy to produce high temperature transducer parameters caused the rapid changes in premature decay. So Slimming transducer is very different with cleaning transducer no matter in terms of material, technology and so on with cleaning transducer
J: The advantage of different driving circuit (Ultrasonic generator)
The driving circuit is divided into Auto excitation type and Separate excitation type , the former is simple and low cost ,can achieve automatic tracking ,but sensitive to load changes , the heat of oscillator is higher ;The latter Separate excitation type is a little complicated , good response to load changes ,however , the heat of oscillator is still high
The sweeping frequency driving circuit from my company inherited the advantages of Separate excitation driving circuit, and can make transducer have a best vibrate chance in a single pulse period, reduce demand of parameter temperature and load changes ,In addition ,the impact force is effective ,lower input power ,lower heat and reliability when ultrasonic vibration working with continuous drive circuit .The occasions of ultrasonic slimming transducer on high output ,large amplitude ,low heat ,so the Separate excitation driving circuit is especially suitable for this application .
K: Why working frequency is different from transducer frequency?
As generally, the transducer frequency tested under small signal is different with working frequency under high electric field.
The actual working frequency is lower 2-3 KHz than transducer frequency because of the load of stainless steel cap and different parameters of inductance. |
