When we perform ultrasonic welding operations, we often fail to meet the product’s use needs due to improper operation. According to our maintenance experience, product defects are mainly concentrated in the strength that cannot reach the desired standard; scratches or cracks appear on the surface of the product; the product is distorted or white. (whitening); damage to internal parts of the product; flash or burrs on the product; dimensional instability after welding of the product.
Only by finding the problem can we solve it. Only by accurately determining the cause of product failure can we deal with it promptly and effectively.

1. The intensity cannot meet the desired standard
The strength of ultrasonic welding operations can never reach the strength of one-piece molding. It can only be said to be close to the strength of one-piece molding. The required standards for welding strength must rely on the cooperation of a number of factors. Therefore, when using ultrasonic plastic welding, you need to consider the strength of the material. Compatibility, melting point difference of plastic materials, density of plastic materials.

2. Scars or cracks on the surface of the product
Ultrasonic operations will produce high heat energy in direct contact with the surface of plastic products and vibration transmission. Therefore, it is necessary to consider coordinating factors such as power output (number of segments), welding time, and dynamic pressure to overcome this lack of operation.

3. The product is distorted and deformed
There are three main reasons for the distortion of the product: the body and the object to be welded cannot match each other due to angles or arcs, the product is thin (within 2mm) and the length exceeds 60mm, and the product is deformed and distorted due to injection molding pressure and other conditions.

4. Damage to internal parts of the product
The reasons for product damage after ultrasonic welding include: the power output of the ultrasonic welding machine is too strong; the energy output of the ultrasonic energy amplifier is too strong; the stress point of the bottom mold fixture is suspended in the air and is damaged by ultrasonic conduction vibration; the plastic product is high and thin and has a bottom Right angle, without setting the R angle to buffer and channel energy; incorrect ultrasonic processing conditions; the pillars or fragile parts of the plastic product are opened on the parting line of the plastic mold.

5. The product produces overflow or burrs
The reasons for product flash or burrs after ultrasonic welding are as follows: the ultrasonic power is too strong; the ultrasonic welding time is too long.
The air pressure (dynamic) is too large; the lower pressure (static) of the upper mold is too large; the energy expansion ratio of the upper mold (HORN) is too large; the fuse line of the plastic product is too outside or too high or thick.

6. The size of the product after welding cannot be controlled within the tolerance.
In ultrasonic welding operations, the product cannot be controlled within the tolerance range for the following reasons:
Machine stability (energy conversion does not add a safety factor; plastic product deformation exceeds the natural ultrasonic fusion range; fixture positioning or bearing capacity is unstable; ultrasonic upper mold energy expansion output does not cooperate; welding processing conditions do not add a safety factor.

We can get a preliminary understanding of more ultrasonic plastic welding materials through the analysis table. If you have more questions about ultrasonic welding operations, you are welcome to enter Lingke Ultrasonic’s official website https://www.lingkesonic.com/ for online consultation. We will We will do our best to answer your questions.