Multihead Weigher Machine
Multihead weigher machine, also known as combination weigher and combination scale, is a kind of weighing equipment with fast measurement speed and high accuracy.
The multihead weigher machine’s working principle is based on combined weighing, mathematical combination calculation is essential in the weighing process.
Multiple weigh hoppers’ measurements can be combined to realize many results, these results are both close to the target weight, then select the most suitable one from the candidate results, the final selected result is closest to the target weight.
Such multi weigher is widely used in food packaging, medicine, chemical, and other industries, and is especially suitable for weighing granular items with irregular shapes and uneven weight, such as candies, frozen aquarium food, chocolates, seeds, etc.
According to the number of weighing hoppers, multi weigher can be divided into 8, 10, 12, 14, 16, 20, 24, 32 head types, each weighing hopper is a separate scale.
The following picture displays the head weigher’s structural diagram, you can learn more about the multi head combination weigher’s components through this picture.
Multi head combination weighers are usually composed of multiple weighing units, each weighing unit includes a storage hopper and a weigh hopper, the storage hopper, weigh hopper are controlled by a microcomputer.
Refer to the following process flow chart, you will better understand the combination weigher’s working process.
- Material feeding
1st, the bucket elevator transports the material to the infeed funnel, then the main vibrator pan vibrates, discharges the material from the infeed funnel, feeds material to each linear vibrator pan.
By adjusting the infeed funnel’s height, the material thickness on each linear vibrator pan can be adjusted.
The material thickness affects the multi head combination weigher’s weighing speed and accuracy.
If the material is too thick, it will affect the accuracy;
And if the material is too thin, it will affect the speed.
- Dosing and weighing
After the material comes out of the main vibrator pan, it evenly enters each linear vibrator pan, then the linear vibrator pan vibrates, the material enters the storage hopper.
When the weighing hopper has completed the last weighing and combined feeding, the storage hopper will then feed the weighing hopper, the weighing hopper completes the weighing, combination, and discharging again.
Read the weight from each weighing hopper, combine them according to the target weight, calculate many many qualified combinations, then select a combination that is closest to the target weight.
- Related parameters of hopper weight
|Automatic Frequency Compensation (AFC)|
|Amplitude of Main Vibrator|
|Amplitude of Linear Vibrator|
|Average Combined Hopper Qty|
|Super Light Weight of Single Hopper|
When AFC is 0
The greater the amplitude of the main vibrator and the linear vibrator, the heavier the weight of each hopper;
When AFC is 1
The larger the average qty of combined hoppers, the lighter the weight of each hopper;
When AFC is 2
The larger the average weight of a single hopper, the heavier the weight of each hopper.
- Combination related system parameters
|Participated Combination Hoppers’ Qty|
- Optimization times
The larger the value, the higher the accuracy.
As shown in figure “combination result graph”, the optimization times is 98, and then select the best group (group 6), which has been combined into the best group, and there is no need to combine again.
- Participated combination hoppers’ qty
The larger the value, the higher the pass rate.
In the combination result graph, if there is no qualified combination, and the participated hoppers’ actual qty≥preset qty, the “compulsory combination emission” will be executed immediately to increase the continuity;
If the participated hoppers’ actual qty＜the preset value, this combination will wait for the last remaining hopper to recombine.
It means discharging the weighed materials to downstream equipment, there are 4 ways:
- Direct discharging (discharge funnel mode 0)
The materials are discharged directly from the multi head scale’s lower discharge funnel.
- Timing hopper discharge (discharge funnel method 1)
After the materials are discharged from the multi weigher’s lower discharge funnel, they are first stored in the timing hopper, and then discharged to the downstream equipment.
Such discharging facilitates the material concentration, shortens the time for materials to fall to the downstream equipment.
- Timing hopper distribution (discharge funnel method 2)
After the material comes down from the multi weigher’s lower discharge funnel, it is first stored in the timing hopper, then according to the two downstream equipment’s discharge request signal, it is sent to the two downstream equipment respectively.
This type of discharging can make full and effective use of the combination weigher’s high-speed performance.
- Timing hopper selection (discharge funnel method 3)
After the materials come down from the head weigher’s lower discharge funnel, they are first stored in the timing hopper.
When unqualified materials are found, the waste discharge motor will be automatically started to remove the unqualified materials, discharge them to the recycle port, prevent unqualified products from entering the next process.
The head weigher has developed rapidly since its appearance in 1972, which is mainly due to its following features.
- High weighing accuracy
The head weigher guarantees the weighing accuracy through the following 3 aspects.
First, during the weighing process, perform a data reading as the first sampling and then combine according to the sampling results.
For example, the weight of certain 4 weighing units is most suitable, but the multihead weigher machine does not immediately release the measured objects, samples them again for their weight data, this is the 2nd sampling.
If the two sampling results are the same, the output signal will be sent, otherwise, the combination will be performed again, thus ensuring the weighing accuracy.
During the weighing process, there will always be leftovers in the hopper.
When the next weighing is performed, the obtained weighing result will be higher than the actual result, which will affect the weighing accuracy.
After the multi head combination weigher sends out the weighing material, the discharge funnel will be opened several times to ensure that there are no leftovers;
At the same time, the multi head combination weigher also has an automatic zero-reset function, so that it will not affect the next weighing.
- Fast weighing speed
The entire weighing process of the multi head combination weigher is mainly controlled by the computerized system.
When a signal comes in, the computerized system will make the corresponding action, and then send out the signal to facilitate the subsequent actions’ completion.
The stepping motor can accurately control the weighing hopper’s opening/closing size and speed.
- Save labor and raw materials
Compared with general electronic scales, multi head scales can save labor and raw materials.
For example, a candy factory (or pistachio, 4g/piece), product specification 200g/bag, 16 working hours a day (2 shifts), 300 working days a year, and an annual output of 3400 tons.
According to the comparison, using a 10 head multihead weigher for quantitative weighing, compared with 5 general electronic scales, can save 8 labor and 53.56 tons of raw materials a year.
On Jun 23, 2021, a Dutch client sent us an inquiry, he requested us to customize a multi head packing machine, such machine should integrate a vertical cartoner and a head weigher, it will be used for packaging 250-1000 grams of seeds per dropping.
SiroSilo has strong customization and integration ability, if you plan to purchase a head weigher or multi head packing machine, please send us an inquiry on this site, we will try our best to get back to you within 1h.
SiroSilo could also supply the following products, if you are also interested in any type, please feel free to send us an inquiry:
Multihead Weigher Machine Ultimate FAQ Guide
Multihead weigher working principle
The working principle of the multihead weigher can be summarized by the 4 steps of material feeding, storing, weighing, and discharging.
When the head weigher is working, these 4 steps are carried out cyclically.
The bucket elevator transports and concentrates the materials to the main vibration plate, which vibrates and transports the materials to the linear vibration plate.
The linear vibration plate vibrates and transports the materials to each storage hopper, and the materials are stored in the storage hopper for a while.
The stepping motor starts to work, opens the storage hopper, and sends the materials in the storage hopper to the weighing hopper.
According to each weighing hopper’s weight, the control system starts to calculate, selects the combination closest to the target weight, and sends a discharge signal.
The discharge signal drives the stepping motor to open the selected weighing hoppers, discharges the material into the chute, and then into the timing hopper.
If there is no timing hopper, it will directly enter the packaging machine and send a discharge signal to the packaging machine.
How does a multi head weigher calculate combinations?
The multi head weigher originated in the 1970s, its weighing principle is derived from the permutation and combination algorithm in mathematics.
At present, the 10 head and 14 head combination weighers are the most widely used in the world.
Now, take a 10 head combination weigher as an example.
The material is distributed into 10 weighing hoppers, and each time the material is fed, the material layer thickness, the material particles’ size & uniformity is different, so the material falls into the weighing hopper has a different weight.
Now suppose that the material weights (in grams) in the weighing hoppers from No. 1 to No. 10 are as follows:
The target weight is 100±0.5.
From the above value, we can find:
No. 1 (28.5) + No. 3 (31.9) + No. 6 (20.5) + No. 10 (19.1) = 100 grams.
Adding the weight values of several weighing hoppers, its value is equal to the target weight value of 100±0.5 grams.
By combining several weighing hoppers’ weight values in this way, precise weighing can be achieved on combination weigher.
Because the combination weigher adopts high-performance weight sampling chip and data processing chip, the whole weighing time is about 0.7s, so that precision weighing can be realized quickly.
10 head multihead weigher
The 10 head multihead weigher is a high-precision industrial scale, it contains 10 weighing hoppers, which are controlled by a microcomputer and have a wide range of applications in the food industry.
The 10 head multihead weigher is suitable for precision weighing of snack foods such as candy, melon seeds, jelly, frozen seafood, pet food, puffed food, pistachios, peanuts, nuts, almonds, raisins, etc.;
For the precision weighing of granular, flake, strip, round, and irregular shape items such as big shell nuts, hardware, plastic pellets, etc., a 10 head multihead weigher is often used too.
14 head weigher
The 14 head weigher is also a high-precision industrial scale controlled by a microcomputer.
The scale contains 14 storage hoppers and 14 weighing hoppers, which weighs faster than the 10 head multihead weigher.
Like the 10 head multihead weigher, the 14 head weigher is also suitable for precision weighing of snack foods, irregular-shaped nuts, hardware, plastic particles, plant seeds, etc.
Multi head weigher parts
The multi head weigher parts are clearly marked out in the following photo, please check it for reference.
Multihead weigher bucket
The multihead weigher’s bucket is also called hopper.
The bucket on the multi head combination weigher mainly includes a storage hopper and a weighing hopper.
After the weighing hopper finishes weighing and discharging, the material in the storage hopper can be continuously fed to the weighing hopper, which can effectively ensure fast weighing.
Multihead weigher manufacturers
Multihead weigher manufacturers are located all over the world because the food industry has a large demand for multi head weighing machines.
The world’s major multi weigher manufacturers have been listed in the figure below.
By browsing these companies’ websites, you can learn more cutting-edge information about multi head weighing machine and the market.
Multihead weigher manufacturers in China
China also has many multihead weigher manufacturers, most of which are concentrated in the economically developed Pearl River Delta and Yangtze River Delta regions.
SiroSilo is one of China’s professional multi weigher manufacturer.
SiroSilo’s third-generation multi head scales have two-year warranty, its attractive features are listed in the following photo:
If you plan to purchase a multi head scale in the near future, you are welcome to leave a message or send an inquiry on this website, and we will try our best to reply within 1 hour.
We also welcome you to visit our factory or video call with us, we can lively broadcast our factory to you.
Multihead weigher price
In the Chinese market, some manufacturers produce combination weighers with good quality, 2-year warranty, and a relatively high price;
The multi head scales supplied by other manufacturers are of normal quality and with 1-year warranty, the price is relatively cheap.
The picture below shows the multi weigher’s reference price in the Chinese market, you can refer to it when purchasing multi weighers from China.
Multi-head weighing machines market
In 2017, the global multi-head weighing machine market volume has reached 203.2 million U.S. dollars, and it is expected that by 2027, this value will increase to 291.65 million.
From the current multi-head weighing machine market, the food industry occupies more than 80% of the share.
Grains, seeds, ready-to-eat foods, fresh produce, candy, snacks, meat, poultry, seafood, etc. can all be weighed by multi head packing machines;
Pharmaceutical, chemical, hardware, spare parts, and other industries often use multi head scales too.
The 14 head weigher has become a hot-selling product in the multi weigher market, the weighing accuracy and speed have been greatly improved.
With the continuous upgrading of multi head scale technology and the continuous enrichment of product categories in the food industry, the multi head weighing machine’s future market is still very broad.
Multi head weigher manual
The hard copy multi head weigher manual will be included in the packaged wooden box when it leaves the factory for shipment.
The soft copy multi head weigher manual has not been uploaded to the website, it is because the user manual file is large, putting it on the website will slow down the website loading speed.
If you want to learn more about how to use the multi head scale first, please email or call us, and we will share the soft copy multi head scale manual with you as soon as possible.
Multi head packing machine
Multihead packing machine is a fully automatic packaging machine integrated with precision weighing equipment, which realizes full automation from material feeding to finished product conveying.
Multi head packing machine mainly includes the following equipment:
- Vibration feeder
- Z-shaped conveyor
- Multi weigher
- Working platform
- Vertical packaging machine
- Finished product conveyor
- Sorting table
Please refer to the following video to learn more about the multihead packing machine’s working process.
Multihead weigher packing machine has a wide range of applications, it can be used to pack jellies, nuts, biscuits, frozen foods, grains, seeds, salad vegetables, etc.