What is Ultrasonic Welding?

Ultrasonic welding uses high-frequency vibration waves to transfer to the surfaces of two objects to be welded. Under pressure, the surfaces of the two objects are rubbed against each other to form a fusion between molecular layers.

Ultrasonic welding is passed

Ultrasonic plastic welding principle

When the ultrasonic wave is applied to the thermoplastic plastic contact surface, it will generate tens of thousands of high-frequency vibrations per second. This kind of high-frequency vibration reaches a certain amplitude. The ultrasonic energy is transmitted to the welding area through the upper welding piece. The welded interface has a large acoustic resistance, which can cause local high temperatures. Also, due to the poor thermal conductivity of plastics, they could not be released in time and gathered in the welding zone, which caused the contact surfaces of the two plastics to melt rapidly, and after a certain pressure was added, they were merged into one. When the ultrasound stops working, let the pressure last for a few seconds to make it solidify and form, so that a strong molecular chain is formed to achieve the purpose of welding, and the welding strength can be close to the strength of the raw material. The quality of ultrasonic plastic welding depends on

1.ultrasonic welding

Welding method in which two pieces of plastic are welded together under the action of ultrasonic vibration due to frictional heat generated on the surface between molecules.

Note for thermoplastic welding:

A. The tongue and tongue design guarantees convenient alignment during the welding cycle.
B. The wire design is slim, but there must be enough fusible material to fuse the welding surface. The specific design method depends on which workpiece equipment is used in the welding. Welding pressure, vibration amplitude and other parameters can be adjusted to ensure that the welding head can contact the welding surface and apply pressure. The lower workpiece is the part that receives the pressure and is not moved in the bottom mold. Due to the ultrasonic high frequency generated by the welding head, the upper workpiece generates heat and vibration, so it can be fused with the lower workpiece. After the welding head stops shaking, the pressure is maintained and the melting position is cooled to form. The entire welding time is mostly less than one second.

2,

Application method of ultrasonic welding

I. Welding method: Welding heads with ultra-high frequency vibration under moderate pressure will cause frictional heat to be generated on the joint surface of two plastics and instantly melt the joints. The welding strength can be comparable to the body, using suitable workpieces and reasonable interfaces. Designed to achieve water and air tightness, and avoid the inconvenience caused by the use of auxiliary products, to achieve efficient and clean welding.

Second, the riveting method: Ultrasonic and ultra-high frequency vibration welding head, pressing the protruding tip of plastic products, so that it instantly heats into a rivet shape, mechanically riveting materials of different materials together.

3. Implantation: Through the preaching of the welding head and appropriate pressure, the metal parts (such as nuts, screws, etc.) are instantly squeezed into the reserved plastic holes and fixed at a certain depth. After completion, no matter the tensile force or torque, it can be comparable to the traditional The strength of the molding in the mold can avoid the disadvantages of damage to the injection mold and slow injection.

4. Forming: This method is similar to the rivet welding method. The concave welding head is pressed against the outer ring of the plastic product. After the welding hair emits ultrasonic and ultra-high frequency vibration, the plastic is melt-molded and covered with a metal object to fix it. Smooth and beautiful, this method is mostly used in electronics, horn fixing molding, and cosmetic lens fixing.

V. Spot Welding: A. Welding two plastic sub-points does not need to design a welding wire in advance, to achieve the purpose of welding. B. Perform spot welding on relatively large workpieces, which are difficult to design the welding line, to achieve the welding effect, and can spot weld multiple points at the same time.

6. Cutting and Sealing: The principle of instantaneous vibration of ultrasonic waves is used to cut chemical fiber fabrics. The advantages are that the cuts are smooth and not cracked or brushed.

1,

(1) When the thickness and hardness of the welding workpiece are increased, the power required for welding increases exponentially, thereby increasing the manufacturing cost of the ultrasonic welding machine. When the required power is too large, the design and manufacture of the acoustic system and the technical effects will produce a series of difficult problems, so currently, it is mainly limited to welding thinner and thinner parts such as wire, foil, and sheet.

(2) The joint form of the current ultrasonic welding system is limited to overlap, and due to the limitation of the tool head, the workpiece can only extend into the size range allowed by the welding system, and the welded joint form and size range are relatively limited.

(3) At present, the quality inspection of ultrasonic welding is more difficult, the general inspection methods are difficult to monitor in real time in the production process, and the non-destructive inspection method has not reached the popular state ^[1]

For all application markets, ultrasonic welding has its unique advantages-fast, efficient, clean and sturdy, and has won recognition from all walks of life.

I. Automobile: (Transportation industry) Ultrasonic can be controlled by computer programs to weld large and irregular workpieces, such as bumpers, front and rear doors, lamps, brake lights, etc. With the development of high-grade roads, more and more ultrasonic welding is used for reflective sheets.

Ultrasonic metal welding machine (Nico ultrasonic Wang Qiang)

2. Appliances: Appropriate adjustments can be used for: portable fluorescent lamp covers, steam ironing doors, TV casings, recordings, transparent panels of sound players, power rectifiers, TV housing screw mounts, mosquito-repellent lamp housings, washing machine dewatering tanks, etc. Sealed, sturdy and beautiful appliances.

3. Packaging: The sealing of the hose and the connection of special packing tape.

4. Toy industry: Due to the use of ultrasonic technology to make the product clean, efficient and firm, it eliminates the use of screws, adhesives, glue or other auxiliary products, reduces production costs, and greatly enhances the competitiveness of enterprises in the market.

V. Electronics: The use of automation scheme design enables users to achieve large-scale production, while ensuring product quality requirements.

6. Other commercial uses: From communication equipment, computer industry, printing equipment to audio-visual products, Minghe ultrasonic equipment can be used.