There are many factors affecting ultrasonic plastic welding effect, and here are some of them.
1. Amplitude in the ultrasonic welding process
The mechanical amplitude output by acoustic system is a very important parameter in ultrasonic plastics welding. From the perspective of plastic sound pattern, due to its different physical properties, the heating rate and temperature rise rate of plastics are different with the welding amplitude. Each material has a minimum amplitude to melt. If the ultrasonic amplitude is not enough, it is difficult for plastics to reach the melting temperature during the welding process, so the welding strength of plastics is closely related to the amplitude.
The ultrasonic amplitude required by ultrasonic plastic welding is adjusted by the shape, size and the material of the booster. In order to ensure the success of welding, the ultrasonic amplitude must be adjusted according to the type of welding materials. In addition, for different welding methods, the ultrasonic amplitude is also different, such as brazing and wool riveting, which require a large ultrasonic amplitude increase; but for plane welding, which requires a small amplitude. The output amplitude of the system welding should be adjusted according to the type of welding parts and welding method.
2. Welding time in the ultrasonic welding process
Ultrasonic welding time means from the ultrasonic wave begins to it ends. If the ultrasonic welding time is longer, there will be more energy passing to the workpiece, so the workpiece temperature will be higher, the more parts in a plastic will be melt; but if the ultrasonic welding time is too long, it could damage parts surface, if the ultrasonic welding time is too short, it can not make the workpiece weld together, so it is very important to control the weld time
3. Cooling time in the ultrasonic welding process
Ultrasonic Cooling time refers to after ultrasonic works, the ultrasonic horn/mould stay on the workpiece. The ultrasonic cooling purpose is to make the product close to each other under certain pressure to make the welding effect better.
4. Welding pressure in the ultrasonic welding process
In general, enough ultrasonic welding pressure should be applied to the workpiece, so that the whole surface has good contact, too low ultrasonic pressure will prolong the ultrasonic welding time, so that the workpiece will produce welding marks or poor quality; Too high pressure will make the workpiece welding surface rupture, so that the interface is not good, affecting the welding strength and welding quality.
The above factors can be adjusted on welding machine, among which welding time, welding pressure and cooling time are considered to be the most important factors affecting welding strength and quality.
Post time: Mar-22-2022