Ultrasonic welding

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Ultrasonic welding Ultrasonic vibrations are produced by mechanical motion of a converter, expanding and contracting some 20,000 times/sec. The vibratory energy is channeled through a horn and applied to thermoplastic materials. This creates the frictional heat to produce a molecular interaction and weld materials.

Contents 1 Process 2 Materials 3 Applications 4 Advantages 5 Disadvantages

Process

Ultrasonic vibration transmitted by a metal tool (horn, sonotrode) causes oscillating flexing of the material and friction between the parts, which results in a closer contact between the two surfaces with simultaneous local heating of the contact area. The plastic melts in the contact area, the polymer molecules are cross-linked, forming a strong joint.

Ultrasonic Welding cycle takes about 1 sec. The frequency of acoustic vibrations is in the range 20 to 70 kHz (commonly 20-40 kHz). The ampltude of the acoustic vibrations is about 0.002” (0.05 mm). Thickness of the welded parts is limited by the power of the ultrasonic generator.

Materials

Ultrasonic Welding is used mainly for processing amorphous polymers (Polysterene (PS), Acrylonitrile-Butadiene-Styrene (ABS))

Applications

• Medical equipment (filters, face mask, valves, cardiometry reservoir);
• Automotive components (glove boxes doors, filters, valves, airflow sensors);
• Appliance (vacuum cleaner, steam iron, dishwasher components);
• Electrical equipment (switches, terminal blocks,connectors);
• Electronic and computer components;
• Toys.

Advantages

• Short welding cycle;
• Easily automated and controllable;
• Small amount of flash forms;
• Low energy consumption;

Disadvantages

• Only small and thin parts may be welded;
• Tool design is required.