Industrial Automation Instruments

Ultrasonic welding equipment for mask machines

(Tel: 13600905985, Manager Zhang)

I. Ultrasonic working principle

Ultrasonic processing of thermoplastic adhesives uses high-frequency friction between the joint surfaces to rapidly generate heat between the molecules

When this heat is sufficient to melt the workpiece, the ultrasonic oscillation is stopped; the joint surface of the workpiece then solidifies from the molten state, completing the processingprocedure.The frequencies commonly used in plastic processing are 20KHz and 15KHz, of which 20KHz is beyond human hearing and is therefore calledultrasound, while 15KHz is still within the range of human hearing.

II. Ultrasonic mechanism principle

Convert 220V, 50HZ into 20KHz high-voltage electrical energy, which is converted into mechanical energy by means of the vibrator. Such mechanical vibration is transmitted through the transmission horn and the die to the workpiece, and air pressure is used to produce a friction effect at the joint surface. The vibrator and the transmission horn are installed in the vibration cylinder with an external die, and are raised and lowered under preset conditions by the air pressure system and the control circuit to complete the operating procedure.

III. Description of the power supply front panel

1. Switch: power switch

2. Current: displays the operating current of the ultrasonic transducer; the normal operating current is 0.2A-0.8A, not greater than 1A;

3. Amplitude: displays the operating amplitude of the ultrasonic transducer; the normal operating amplitude is 0.2-0.8 or 2-8 (the amplitude meters of the power supply

have different scales 0~5 and 0~50), not greater than 1 or 10;

4. Overload: indicates whether an overload occurs. During normal operation the overload lamp is off; in case of overload, a red light is displayed;

5. Sonic test: press briefly or press and hold (for no more than 3s) this button; the transducer operates, and the current meter and the amplitude

meter show readings. Used to check whether the power supply output is normal;

6. Frequency adjustment: adjust with a Phillips screwdriver according to the actual welding conditions.

VI. Frequency adjustment

The power supply and the ultrasonic transducer have been fully adjusted before shipment. If the welding result is poor or the current and amplitude are too high, the frequency may be adjusted;otherwise do not adjust the frequency. If adjustment is required, follow the steps below.

Note: When adjusting the frequency, the ultrasonic equipment should be in a non-operating state (i.e. the “Control input” terminal is open and there is no load on the die), and the transducer and the die must be cold.

1. Press briefly or press and hold (no more than 3s) sonic check, while continuously adjusting the frequency adjustment knob;

2. Under no-load conditions, observe during adjustment that the overload indicator does not alarm and that the current and amplitude remain within the normal range

3. While meeting the welding process requirements, the readings of the current meter and the amplitude meter should be as low as possible.A persistently high current

will damage the equipment.

4. If the overload lamp lights up during frequency adjustment, release the sonic check button immediately to avoid shortening the service life of the power supply or damaging internal components.

5. After adjustment is completed, tighten the locking knob at the bottom of the adjustment screw.

VII. Transducer usage requirements

Because the power ratings of our products are actual values, the ultrasonic vibrator and die will generate a large amount of heat during normal use. A high-flow fan must be installed to cool the vibrator and the die (see the illustration below); otherwise, as the temperature rises, the welding result will deteriorate and, in extremecases, irreversible damage will occur.