How to solve the unstable quality of ultrasonic welding
Best way to choose a large unit of ultrasonic welding equipment
The quality cannot be stabilized. The main factor is that the output power cannot be stabilized, resulting in the inability to form stable frictional heat.
There are four factors to stabilize the power output
1.The output power of the machine;
2.HORN expansion ratio;
3.Air pressure source;
The details of the four main factor :
1. Machine output power + HORN expansion ratio = actual available power. It can be seen that when ultrasonic welding is implemented for a certain product, from the point of view of planning and design, the stronger the output power of the machine, the smaller the enlargement relative to the HORN design.
Conversely, the smaller the output power of the machine, the larger the enlargement ratio of the HORN design. For example: 2200W ultrasonic welding machine, HORN expansion ratio is 2.5 times. When changing to a 3200W ultrasonic fusion splicer, the expansion ratio of HORN may only be 1.5 times. However, it is not emphasized that the output power of the ultrasonic welding machine should be large, but when ultrasonic welding is performed on a plastic product, a suitable environmental operation is required. In the process, the cost budget, the functional requirements of the product, and the welding standard must be considered. Then come to plan out a complete working equipment and ultrasonic use skills.
2. After understanding the above-mentioned key reasons that affect the quality of ultrasonic welding, engineers should be familiar with and evaluate 1. Product quality requirements and functional standards; 2. Existing ultrasonic equipment;
3. Determine the form and skills of product design (such as ultrasonic wave guide fuse, product positioning, material). Since the available equipment resources have been fixed, it is correct to use product design skills to match the available equipment.
4. When we determine that there is no problem with human factors (items 1 to 2), unstable quality will occur. That is a certain fact: the influence of air pressure and voltage. When we deal with the phenomenon of instability in quality for many years, we also found that the quality standards that could not be reached during working hours were unexpectedly met when everyone was off work and stopped the voltage and air pressure at the same time. Therefore, it is also found that when multiple people or multiple units use a common air pressure and voltage source, because the air compressor usually sets the air pressure in the air storage cylinder to be lower than 2 ~ 4kg, the air will be automatically pumped and filled. This is a result. The cause of the error. When the air pressure source reaches the welding machine through the pipeline, due to the fast welding speed, the air pressure of the sub-ultrasonic welding and the air pressure remaining in the pipeline for the second or third time will also form an error, which will form a periodic or aperiodic Quality changes. And because the voltage is also used by millions of people at the same time, the voltage drop generated at this time is beyond our control. Such variables in air pressure and voltage can indeed cause changes in energy output, and affect An important factor in precision quality. Of course it must be listed as a diagnostic item.
If you want higher quality, if the product demand is less than 0.02m/m, or the weld line fusion status needs to be more than 90%, the design engineer must follow the planning sequence.
1. Familiar with ultrasonic welding equipment;
2. Determine product functions;
3. Familiar with the corresponding relationship between ultrasonic and plastic welding;
4. Add voltage stabilizing equipment as much as possible.