Both ultrasonic sealing machine and hot melt sealing machine are used for hot melt plastic sealing. However, there are also many differences between them.

1. Different Principle

Ultrasonic sealing machine converts electrical energy into high-frequency and high-voltage signal which act on the contact surface of plastic products through ultrasonic transducer system. As a result, temperature is increasing for friction. When the temperature reaches the material melting point, it will immediately melt and is finally sealing after a certain pressure of cooling and forming. Therefore, the sealing is fast and good without any auxiliary, the appearance is beautiful. This kind of sealing method has little impact on chemical agents and no surface pollution, avoiding the shortcomings of using adhesives or hot melt welding.

1.1. Strips Tube Filling and Sealing Machine

Sealing principle:

It uses mechanical wave to seal, which is composed of a power supply system and an ultrasonic vibration system. With reciprocating high-frequency and high-power mechanical energy, plastic is melted and sealed through ultrasonic sealing, which requires pressure to seal the tube.

1. Don’t need the cooler or cool water.

2. Low power consumption, energy saving.

3. Ultrasonic only provides vertical and overlap sealing lines.

4. Speed of Filling and Sealing Machine is up to 15-20 strips /min.

5. Double-layer plastic pipes can be sealed closely.

Hot melt sealing machine seals the product by a temperature controller which controls temperature of the heating mold. If the mold reaches the set sealing temperature, the cylinder drops so that the mold is aligned with the product sealing point which will begin to melt. Under the pressure of the cylinder, the sealing point on the product surface is melting in a certain degree. Afterwards, the cylinder rises, and the sealing point solidifies and forms at room temperature to achieve the purpose of sealing.

1.1. Tube Filling and Sealing Machine

Sealing principle:

By converting electrical energy into thermal energy, the plastic will dissolve, and by pressurizing the mold, the tube walls will fuse and seal together.

1. A chiller is required to provide cold water and maintain the mold at normal operating temperature..

2. When start the machine, start the heating mold first to make the sealing mold to reach the melt temperature of the material. After production, close the heating mold while keep the chiller working to cool down to room temperature. Then turn off the power supply.

3. Various sealing lines and shapes are available.

4. Sealing speed is up to 30-50 pcs/min.

1. Different Applicable Temperature

Ultrasonic sealing machine is suitable for thermoplastic sealing, artificial fiber cloth melting (masks, disposable surgical gowns, bra straps), strips tube filling sealing machine, etc.

Hot melt sealing machine is suitable for computer consumables, calculators, toys, telephones and others which display zebra connection, riveting of plastic parts, plastic forming process, plastic tube filling sealing machine, etc.

Apply ultrasonic or hot melt sealing process depends on the plastic and film material. When use ultrasonic sealing to seal waterproof and air-permeable film, the plastic parts should be hard plastics, such as: nylon, PE,PP,PC, ABS, PS, etc. While hot melt sealing can be used for soft plastics, such as: PVC,EVA, rubber, etc.

If seal waterproof and air-permeable film with hot melt sealing, the plastic parts are heated with high temperature. However, the films have different high temperature resistances, so people apply not hot melt but ultrasonic sealing for plastic parts with high melting point and air-permeable film.