Ultrasonic hook and loop heat sealing machine, also known as a hook and loop welding machine or ultrasonic plastic welding machine, is a device that uses ultrasonic technology to fuse materials such as hook and loop fasteners, backpack buckles, webbing, and elastic bands. Below is a detailed introduction:

I. Working Principle

The working principle of the ultrasonic hook and loop heat sealing machine is based on the energy generated by ultrasonic vibrations. When ultrasonic waves act on the contact surface of thermoplastic plastics, they produce high-frequency vibrations of tens of thousands of times per second. These high-frequency vibrations, reaching a certain amplitude, transmit ultrasonic energy to the welding area through the upper welding component. Due to the high acoustic resistance at the welding area—the interface between the two materials—localized high temperatures are generated. Since plastics have poor thermal conductivity, the heat accumulates in the welding area, causing the contact surfaces of the two plastics to melt rapidly. At this point, applying a certain pressure allows them to fuse into one. After the ultrasonic waves cease, the pressure is maintained for a few seconds to allow solidification, forming a strong molecular chain and achieving the welding purpose.

II. Main Methods

The ultrasonic hook and loop heat sealing machine employs various welding methods to accommodate different materials and requirements:

Fusion Welding: Ultrasonic vibrations are transmitted through the welding horn to the workpieces. Due to high acoustic resistance at the interface, localized high temperatures are generated, melting the contact surfaces. Under a certain pressure, a visually appealing, fast, and strong fusion weld is achieved.

Embedding (Insertion) Method: Nuts or other metal parts are inserted into plastic workpieces. Ultrasonic waves are first transmitted to the metal, causing high-speed vibrations that directly embed the metal into the molded plastic while melting the plastic. After solidification, the embedding is complete.

Riveting Method: To join metal and plastic or two different types of plastics, ultrasonic riveting can be used, resulting in a joint that is resistant to brittleness, aesthetically pleasing, and strong.

Spot Welding: A small welding horn is used to weld large plastic products at specific points, or a row of toothed welding horns is pressed directly onto the workpieces to achieve spot welding.

Forming Method: Ultrasonic waves are used to instantly melt and shape plastic workpieces. As the plastic solidifies, it firmly bonds with metal or other plastic materials.

Cutting Method: Special designs of the welding horn and base allow direct pressure on the plastic’s branches immediately after injection molding. Ultrasonic transmission achieves the cutting effect.

III. Main Features

No Auxiliary Materials Required: No need for adhesives, fillers, or solvents, and minimal heat consumption.

High Welding Strength: The weld strength is close to that of the original material, meeting various application requirements.

Rapid Setup: Short molding cycle and convenient installation, improving production efficiency.

High Automation: The control system automates the entire welding process. Operation requires only pressing a button to generate a trigger pulse, automatically completing the welding cycle.