Solve the problem of water and air tightness during welding with ultrasonic welding machine

Ultrasonic welding machineHow to solve the water-tightness during welding:
In order to achieve watertight and airtight functions, positioning and ultrasonic fuses are the keys to success. Therefore, the factors considered in product design, such as positioning, material, thickness, etc., have a relative relationship with the corresponding proportion of ultrasonic waveguide fuses. Under the general requirements of water tightness and air tightness, the height of the melting line should be within the range of 0.5~0.8m/m (depending on the thickness of the product). If it is less than 0.5m/m, unless the positioning setting is very standardized and the meat thickness is greater than 5m/m, the water tightness should be achieved and the effect is not good. In general, the positioning of waterproof products and ultrasonic wave guide fuses is as follows:
Bevel type: suitable for welding water tightness and large products. Contact surface angle=45°, x=w/2, d=0.3~0.8mm is appropriate
Step type: Suitable for water tightness and methods to prevent protrusions or cracks. The contact surface angle is 45°, x=w/2, d=0.3~0.8mm is better
Peak-to-valley tip type: suitable for watertight high-strength welding, D=0.3~0.6mm, the contact surface height h varies with the shape, but h is about 1~2mm
Problem 2: Improper welding conditions
In addition to ultrasonic fuse, fixture positioning, product positioning and other factors, the conditions set by ultrasonic are also the main reasons. This article further discusses another reason for good water tightness (welding conditions). When implementing ultrasonic welding operations, the basic goal is to pursue efficiency and speed, but the essence of the pursuit of efficiency is often overlooked. We will discuss the following two conditions:
1. The descending speed and buffering speed are too fast: the formation speed causes the dynamic pressure and the acceleration of gravity to flatten the ultrasonic conductive fuse, so that the fuse cannot play the role of the fuse, forming a pseudo-phase welding
2. Welding time is too long: because plastic products receive heat for too long, it will not only melt the plastic material, but also cause the plastic tissue to coking, resulting in trachoma, and water or gas infiltration. This is a difficult place for ordinary production technicians to find.