These advantages in the coming articles cannot be called advantages even. They become advantages just because others were not willing to design some routine but good mechanical for users. The ultrasonic system is on of them.


Machine manufacturers in our industry, after-sales cost high!

Bag manufacturers in China has excellent hands-on ability. All they have learnt to repair the machine somehow.

When you buy a machine, you often need spend at least 10% of the machine cost to buy something. These are not consuming parts but as important as consuming parts… for avoiding unexpected breakdown.

People in our industry often have a strong heart on ultrasonic sets, because either those who buy the machine, or who makes the machine, or even the parts supplier of the machine … all of them don’t know whether your new machine will breakdown in 3 years, or 3 months, or 3 days …

Noted! Trigger Warning!

“I want to cry after I buy it.” … This is the idea of ​​the customer after suffering the bitterness.

“I want to throw this machine into the river.” … This is an unbearable customer, but in fact, he have to endure again from the beginning because he don’t know better choice.

Some customers are very dissatisfied with the machine, and have a bad temper. After finish their temper, they still have to continue to buy.

The most typical customer we’ve known, because shift to new factory which has no stable voltage even with stabilizer, they almost repair their ultrasonic generator once every 10 days.

If there is any positive news … your competitors suffer same things as you.
The most frequently accessories they suffer: Ultrasonic Sealing Parts!!!


The non-woven fabric is changed from the original fabric to a finished bag on the bag making machine, and various modules require ultrasonic sealing technology.

One ultrasonic set is divided into three parts: cabinet, transducer, and sonotrode. When these three things are combined, ultrasonic waves can be emitted, and then a sealing anvil can be used to achieve ultrasonic sealing. Each machine has many ultrasonic sets on, and some of them can have more than 10 sets.

Ultrasonic Generators on Non-woven Bag Making Machine

Machine Model Quantities of Ultrasonic Sets
MJNB1300 6 sets
MJNBH700 13 sets
Beyonder 10 sets
Quantities of ultrasonic sets on different machines


Other components can be temporarily replaced by local purchases with short downtime, such as motors and drives. However, ultrasonic is an exclusive accessory for non-woven bag making machines.

If there is no stocking accessories, we have to wait a long period of time: consultation and negotiation with supplier, air transportation and customs clearance etc. Express delivery accessories are short for 7 days and long for a month. If what you need was another, repeat the long time again.

Its international express delivery costs are high, as ultrasonic transducers and sonotrode are made of steel. The smallest 153 mm sonotrode costs $100 to East Africa.

Ultrasonic Generators on Unwinding Unit
Ultrasonic Generators and Sonotrodes


The sonotrode collide with anvil – steel collision 120 times/ min, 7200 times/ hour, which can be seen by unaided eye . Other types of sonotrode on the market are not up to the task, please simply give up buying from another place except your original machine supplier.

Sealing Part Ultrasonic Working Intensity Ultrasonic Position
Bag Mouth Continuous Sonotrodes for Bag Mouth Sealing
Side Sealing up to 120 times/min Sonotrodes for Side Sealing
Handle Sealing up to 120 times/min Sonotrodes for Handle Sealing
Triangle Sealing up to 120 times/min Sonotrodes for Triangle Sealing
V-Shape Sealing up to 120 times/min Sonotrodes for V-Shape Sealing(on Beyonder machine)

The internal steel structure of the transducer and sonotrode that could not be seen vibrate 19,000 times per second, 1.14 million times per minute, and 68 million times per hour. Such a high vibration frequency stimulates the internal structure change.

honey beeImage by JamesDeMers from Pixabay

Bees vibrate only 200-400 times/second

No one succeeded, even if a famous brand in Germany or a certain brand in Taiwan who has advanced electronic generator. The sonotrode of aluminum alloy or even titanium alloy can do nothing as well. For those who lack professional knowledge of materials engineering, it’s advised to buy the brand that the smart Chinese customers has chosen for many years.



ultrasonic generator


According to capacity, it is divided into 2200W, 2600W, 3800W, and 4200W, which correspond to different uses. 1500W is applied on the ordinary bag making machine.

Tip: The operation is stable under the same working conditions, if total power is large, the load capacity is large. And while the failure rate is low, and the service life is long. Since the operating power is only a few hundred watts and the short wave is generated, it comsumes the power little.


Mobile user need to view in landscape mode

No. Iterm MJ Ordinary Influence
1 Power Tube (Transistors) Toshiba ( Japan) Chinese brand,
or fake Toshiba
Easy to burn
2 Main Board Superior Same as manual sewing machine Weak, easy to burn
3 Transformer × Unable to adjust power or filter wave to protect the whole set
4 Filter Capacitor × Filter is necessary
5 Breaker × Fundamental barrier of generator burn
6 Main board overload protection × Core barrier of main board burn
7 Digital Display × Can’t estimate frequency without professional measuring tool
8 Weight 14.1kgs 6.73kgs more than 2times


Professional Name: Piezoelectric

Accessories easy to breakdown: Ceramic Slices


Not all customers can change. The grade 12.9 alloy steel pre-pressure screw presses the slices in advance. The screw may breaks, the power is weak, transducer can’t work stably if not professional operated.


1. Material

There are many kinds of materials for the sonotrode. At present, alloy steel is commonly used. Even aluminum and titanium alloys are only a little better, while the cost is unbelievable high.
Both suppliers and users have headache on sonotrode’s 1-5% failure rate, but it’s a must if we make bags in an industrial mass-producing method.

Many people tried hard to develop different materials to get more stable functions, but failed. What we can do feebly now is 24 or 72 hours fatigue test.

Be sure to purchase enough accessories when buying the machine. Being shipped with the machine is regarded as free in a same container.

2. Why the failure rate reaches this high?

Although I have a steel body, I have a glass heart.

  • No more suitable alloy materials
  • Amplitude problem
    Ultrasonic amplitudes for other applications range from 20-30 um, and non-woven bag making machines range from 40-50 um. When 15 kHz, 300 mm sonotrode works upon fabric of 35 grams or less, the frequency is low and the amplitude is large, sonotrode damages easily.
  • The sonotrode does not match.
    The entire workshop could be filled with the collision sound of iron and iron. When the internal structure undergoes cumulative deformation or rigid fracture, a sonotrode that does not have a problem in appearance. But it’s already scrapped and cannot be repaired.
  • Superposition of various working conditions
    Bag mouth folding, sealing roller with knife, handle sealing, handle folding, triangle sealing and V-Shape sealing …


parameter matching

The matching of analog data is a professional skill. Since the various components are provided by different suppliers in the market, only bag making machine’s manufacturer knows how to set the calculation methods to match those particular working conditions.

The matching level decides ultrasonic set quality is good or bad.


You are obliged to provide it with good working conditions so that it can serve you smoothly.
When the ultrasonic set fails, please don’t blame the quality problem immediately, but reflect on whether it is improperly used.

Good accessories run across bad conditions, like drive a super sports car go “off-road”.