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Sep. 07, 2026
A multihead weigher is an automatic weighing system that uses several independent weighing hoppers to create the most accurate combination for a target weight. Connected to a vertical form-fill-seal machine, premade pouch machine, or other packaging equipment, a multihead weigher packing machine can weigh and dispense products such as snacks, confectionery, frozen foods, grains, seeds, and hardware parts at high speed. For manufacturers, this technology reduces giveaway, improves packing consistency, lowers labor costs, and supports reliable production-line automation.
A multihead weigher, also called a combination weigher or computerized combination weigher, is a machine composed of multiple weighing heads arranged around a central discharge chute.
Each weighing head normally includes:
The machine divides the incoming product into many small portions. Its software then calculates which hopper combination is closest to the programmed target weight.
For example, if the target pack weight is 100 g, the machine may select four hoppers containing 24.8 g, 25.3 g, 24.6 g, and 25.2 g. The combined weight is 99.9 g, which is closer to the target than many individual hoppers could achieve.
This is why a combination weigher packing machine is generally more accurate and faster than a single-head scale for irregular, free-flowing products.
Before computerized combination weighing became common, many factories relied on:
These methods were useful, but each had limitations. Manual weighing created labor and consistency problems. Volumetric filling depended heavily on product density. Single-head scales often required a longer filling cycle because one weighing hopper had to complete the entire dose.
Multihead weighing technology became commercially important as food processors and packaging companies demanded:
Today, manufacturers such as Yijianuo use digital load cells, programmable logic controllers, touchscreen HMIs, memory-based recipes, and servo-controlled discharge systems to improve weighing performance.
The operating principle is straightforward, although the calculation process is highly optimized.
Product is supplied from an infeed conveyor, elevator, or storage hopper. A central dispersing cone distributes the product toward multiple radial channels.
The distribution system must be adjusted to match the product’s:
A fragile product, such as potato chips, requires gentler handling than dense hardware components.
The radial feeders direct product into individual weigh hoppers. Each hopper contains a portion of product and is monitored by a load cell.
The load cell converts mechanical force into an electrical signal. The controller then calculates the actual weight of each hopper.
Many modern systems use high-resolution digital signal processing to stabilize readings quickly. However, actual accuracy depends on product characteristics, machine configuration, environmental conditions, and the specified tolerance—not only on the sensor resolution.
Once several hoppers contain product, the computer analyzes possible combinations.
For a target weight of 500 g, the controller may compare combinations such as:
| Combination | Total Weight | Difference from Target |
|---|---|---|
| Hoppers 1 + 4 + 7 | 498.6 g | -1.4 g |
| Hoppers 2 + 5 + 8 | 500.2 g | +0.2 g |
| Hoppers 3 + 6 + 9 | 502.1 g | +2.1 g |
The system selects the combination closest to the target, often within the programmed tolerance. This calculation is completed in milliseconds while new product is being prepared.
After selecting the best combination, the corresponding hopper gates open simultaneously or in a programmed sequence. The product falls through the discharge chute and enters the packaging machine.
The empty hoppers immediately begin receiving a new product portion. This overlapping operation is what allows a combination weigher packing machine to achieve high throughput.
The weighed portion can be sent to:
The packaging machine forms or opens the package, fills it, seals it, codes it, and discharges it to a conveyor or checkweigher.
A complete multihead weigher packing machine normally includes more than the weighing head itself.
The weighing unit includes the hoppers, load cells, feeder channels, and discharge gates. Common configurations include 10-head, 14-head, 16-head, 20-head, and higher-capacity systems.
More heads can create more possible combinations, although the best configuration depends on the product and target weight.
The PLC and touchscreen HMI manage:
Recipe storage is particularly valuable for factories that pack several products or package sizes.
An inclined conveyor, bucket elevator, or Z-type conveyor feeds the product into the weigher. The conveyor should maintain stable product flow without excessive impact or segregation.
The weigher communicates with the bagger through signals such as:
Correct synchronization is essential. A high-performance weighing system cannot deliver its full benefit if the bagger runs too slowly or causes repeated waiting cycles.
The discharge chute must suit the product. Sticky, dusty, oily, or fragile products may require special surface treatment, hopper geometry, or anti-static measures.
Combination weighing is best suited to products that are relatively free-flowing and can be divided into repeatable portions.
Typical applications include:
The machine is less suitable for highly sticky pastes, liquids, large irregular products, or products that bridge easily unless it is specially engineered.
For mixed products, a multihead weigher can also support combination mixing. Separate product types may be delivered through different weighing channels, allowing the system to create a target recipe such as:
The exact configuration depends on the number of product types, recipe accuracy, and sanitation requirements.
The practical value of a combination weigher packing machine comes from the relationship between accuracy, speed, and labor efficiency.
Manual or volumetric filling often adds extra product to avoid underweight packages. A combination weigher selects a close mathematical combination, helping reduce overfill.
Even a small reduction in giveaway can produce meaningful annual savings when a factory packages several tons of product each day.
Because the machine weighs several portions at the same time, it can complete many cycles per minute. The final rate depends on the product, target weight, number of heads, bagger speed, and operating conditions.
Suppliers should confirm speed using a product sample and a defined test protocol rather than relying only on a catalog maximum.
The system records each hopper’s weight and applies the same programmed logic to every cycle. This improves batch-to-batch consistency compared with manual dosing.
Operators still need to load materials, monitor alarms, perform cleaning, and complete quality checks. However, automated combination weighing can reduce the number of workers required for repetitive weighing and filling tasks.
Stored recipes allow operators to change target weights and product settings from the HMI. Tool-less or quick-release contact parts can also simplify sanitation and changeover.
Both systems have useful applications, but they work differently.
| Feature | Multihead Weigher | Linear Weigher |
|---|---|---|
| Weighing principle | Selects a combination of hopper weights | Fills one or more lanes to a target |
| Typical accuracy | High for suitable free-flowing products | Moderate to high, depending on product |
| Speed | Generally higher | Generally lower |
| Product giveaway | Usually lower | Can be higher |
| Best for | Snacks, candy, frozen food, mixed products | Granules, powders, simple products |
| Initial investment | Usually higher | Usually lower |
| Recipe flexibility | Excellent | More limited |
A linear weigher may be the better choice for a simple, stable product and a lower production volume. A multihead system is often more suitable when accuracy, speed, and product variety are priorities.
More heads create more possible combinations, but they do not automatically guarantee better results.
Performance also depends on:
A correctly configured 14-head machine can outperform a poorly matched 20-head machine.
No weighing machine performs identically with every material. Dust, oil, static electricity, moisture, bridging, and irregular particle size can affect the weighing cycle.
A responsible supplier should conduct a product trial and report measurable results, including:
A display resolution of 0.01 g is not the same as a guaranteed package accuracy of ±0.01 g. Resolution, repeatability, linearity, and overall weighing tolerance are different specifications.
For mechanical fabrication, a tolerance such as 0.01 mm may be relevant to a machined component. For a weighing system, buyers should request validated data for repeatability and target-weight accuracy under actual production conditions.
A multihead weigher controls the filling process, while a checkweigher verifies the finished package. These are different functions.
For regulated or high-value products, 100% in-line weight inspection can help identify:
The required inspection method should match local legal metrology rules and the customer’s quality system.
Stainless steel construction is important, but hygienic design involves much more:
For food applications, the buyer should evaluate the complete hygienic design and cleaning validation process.
Quality claims should be linked to clear standards and test methods.
Depending on the market and application, buyers may review:
ASTM and DIN standards are not substitutes for weighing regulations. They should be cited only when the specific component or test is covered by that standard.
Before purchasing a machine from Yijianuo or another manufacturer, request:
A supplier may offer a 24-hour response target for service inquiries, but the contract should define what “response” means, the supported time zone, and the expected resolution process.
Consider a snack manufacturer packing 100 g potato chips.
The production requirements are:
A suitable line may include:
The weigher selects a combination close to 100 g, while the packaging machine forms and seals each bag. The checkweigher then verifies every completed package. Production data can be reviewed to identify trends such as increasing overfill, unstable product flow, or excessive rejects.
For fragile snacks, the machine should be tested for drop height, feeder vibration, and product damage. A supplier should not evaluate success based on weight accuracy alone.
A mixed-nut producer may need every package to contain a consistent recipe. A multi-product combination weighing system can assign different hoppers or weighing sections to different ingredients.
The control system can coordinate:
This application is more complex than single-product weighing because the system must control both total weight and composition. Product segregation, different bulk densities, and oil content must be considered during testing.
Before requesting a quotation, prepare the following information:
The most reliable purchasing process includes a sample test. Ask the supplier to record the actual average weight, standard deviation, maximum speed, product damage, and reject rate.
Even a high-quality combination weigher packing machine requires disciplined operation.
Recommended practices include:
Calibration frequency should be determined by risk, operating environment, legal requirements, and the site’s quality management system. A daily verification check may be appropriate for some production lines, while formal calibration follows the company’s documented metrology program.
No. It is widely used for food, but it can also weigh pharmaceutical products, pet food, seeds, plastic parts, fasteners, and other free-flowing items. Product-contact materials and hygienic requirements vary by application.
The answer depends on target weight, product behavior, required speed, hopper volume, and accuracy. A product trial is more reliable than selecting a head count based only on machine size.
Yes. Many systems store multiple recipes for different target weights and packaging formats. Mechanical change parts and bagger adjustments may still be required.
No. It can reduce giveaway, but product variability, legal minimum-weight rules, operating speed, and machine setup still affect the final result.
In most packaging applications, the terms refer to the same basic technology. “Multihead weigher” emphasizes the machine’s multiple weighing heads, while “combination weigher” emphasizes the software process of selecting the best hopper combination.
A multihead weigher divides products into multiple portions, measures each portion independently, and selects the best combination to reach the target weight. When integrated with a bagger, checkweigher, metal detector, and appropriate conveyor system, a combination weigher packing machine can improve throughput, reduce giveaway, and provide more consistent package control.
The best solution depends on product behavior, target weight, packaging format, hygiene requirements, legal metrology, and verified production data. Businesses evaluating a multihead weigher packing machine should request product testing, documented accuracy results, standards information, commissioning support, and a clear service plan from Yijianuo or another qualified supplier.
