Bonding process of ultrasonic cleaning transducer in ultrasonic cleaning machine

Publish Time: 2019-05-23 Origin: Site

1, preparation

According to the requirements of the consumption obligation sheet, carefully reflect and confirm, and prepare the ultrasonic transducer (with the right pair), the cylinder block, the mesh mat, the glue, etc. that need to be glued.

2, sandblasting

The ultrasonic cleaning transducer and cylinders to be glued are stopped for sandblasting. The sandblasting joints should be as fine as possible. Sandblasting should use 30-mesh diamond sand. The sand must be kept dry and often picked (every time in the sandbox) All should be selected), the pressure of the compressed air during sandblasting should be ≥6KG, and the high-pressure air after dehumidification by the air source processor.

3, cleaning

Stop the cleaning of the sand-filled cylinder block and the ultrasonic transducer. The transducer is first cleaned with methanol, the dust on the surface is removed, and then rinsed with acetone. The cylinder is washed with water and then pickled. Rinse clean, dry and then rinse once with methanol and acetone. The mesh mat is cleaned with a stainless steel mesh of ≤30 mesh thickness ≤0.15 (electrolyzed under conditions).

4, drying, preheating

Put the cleaned ultrasonic transducer and the cylinder block and mesh mat into the oven to stop drying. Dry it at 60 °C-80 °C for 2 hours and then cool to 40 °C to stop the bonding. After all the glue preparation tasks are completed, the glue (normal temperature) is fully tempered and the glue is stopped quickly.

5, glued

a) Place the disposed cylinder on the glued plate and wipe it again with a cotton cloth at the glue joint.

b) Wipe the treated ultrasonic cleaner transducer bonding surface with acetone and wipe it again with cotton cloth.

c) Pre-heat for 1-2 minutes after mixing with the glue. (The glue should not be too much for each configuration, the glue is 20-30 heads at a time.) The glue is configured as 5G/head with a ratio of 1:0.4 (adhesive is more accurate than curing agent).

d) Stop the glue when the cylinder and ultrasonic transducer are cooled to about 40 °C. When bonding, identify the average glue on the cylinder and ultrasonic transducer, put the net on both ends, and then press firmly, glue The speed is fast, and the glue bonding time should not exceed 10 minutes after each time the glue is configured (requires sufficient preparation for the task). ,

e) Stop the pressure treatment after the glue is finished (should be sung, spring soft pressed).

6, curing

Put the glued cylinder into a dust-free oven to stop curing. After curing at 40-50 °C for 30 minutes, the temperature is heated to 60-70 °C for 30 minutes and then heated to 80 °C for three times. After 2 hours, it was naturally cured for 24 hours and the connection was checked. The curing and heating are controlled by a programmable temperature controller.

7, testing

The curing of the cured ultrasonic transducer is stopped. The impedance of each transducer (60W, 22, 25, 28KHZ) is about 250Ω, which cannot exceed 300Ω, and the transducer characteristics are stopped. Wave), the impedance value of the ultrasonic transducer on the same cylinder should be as close as possible to the difference, and should not exceed 20% of the uniform value (about ±50 Ω), and the ultrasonic transducer can be removed and re-bonded.

8, connection

For the detection of the defective whole piezoelectric ceramics ring ultrasonic transducer stop connection, the connection uses 75W soldering iron to firmly connect, can not have virtual welding, the positive and negative poles use different colored wires, the positive line should be set with yellow wax casing, the initial heat Shrink the tube and cover all the joints.

The insulation test of the whole-cylinder ultrasonic transducer after the connection is completed: the measurement is carried out with a common 3721 digital megohmmeter. When the voltage is 2500V, the insulation of the whole cylinder should be ≥1000MΩ or more (air humidity ≤60% at the time of detection). Below this value, you should look for the cause and re-dispose.

Third, the storage of glue

The glue should be kept in the freezer, and the refrigerating temperature should be 0-5 °C. The glue that has been used up at the end of the can should be covered and sealed with sealing tape and put into the refrigerator; the shelf life of the control glue should always be reflected. It is necessary to make early advances and early use, and it is not necessary to expire.

Fourth, the environmental requirements

Ultrasonic transducer workshops should always adhere to a clean, boring sanitation environment, and the workshop should always clean, dust, and dehumidify.

a) The temperature of the workshop should be maintained at 15-20 ° C and humidity ≤ 50-60%.

b) The workshop should be cleaned at least once a day (using drag and wipe), and should be dehumidified and polluted in time after cleaning.

c) Smoking is strictly prohibited in the workshop, and doors and windows are closed as usual.

d) When disassembling the ultrasonic transducer, wear a good task suit and a white cotton glove. It is strictly forbidden to operate by hand.

e) The oven should always be cleaned and adhered to a good shape.

f) the utensils used should always be kept clean