Combination weighing
Useful where a population of portions gives the controller many ways to meet the target and the product can distribute consistently around the machine.
Operating principle
A combination weigher selects portions; a linear weigher controls feed into one or more weigh hoppers.
In a combination system, multiple weigh hoppers create available portions and the controller selects a combination close to the target. A linear weigher normally uses coarse and fine feeding into a smaller number of hoppers or lanes. Neither route is automatically better for every product.
Linear weighing
Often simpler for moderate output, larger target weights or products that feed predictably through controlled coarse and fine vibration.
Application trial
The final decision should be based on weight data, sustainable output, product quality, cleaning and pack integration using the same product and acceptance method.
Decision matrix
Compare the whole application rather than one headline figure.
| Selection factor | Combination / multihead | Linear / multi-lane |
|---|---|---|
| Target creation | Selects a combination from multiple weighed portions | Controls product feed into one or more weigh hoppers |
| Product distribution | Requires stable central distribution and portion population | Requires consistent lane feeding and coarse/fine control |
| Output potential | Can support high cycle demand where product and packer allow | Can be practical for moderate output and simpler operation |
| Large or bulky pieces | Hopper volume and distribution become important | Lane width, hopper size and discharge path become important |
| Cleaning and changeover | More contact parts and hoppers to release, inspect and refit | Fewer lanes may simplify some cleaning tasks |
| Integration | Commonly uses a timing hopper for VFFS or pouch demand | Can discharge manually, by foot pedal or to downstream machinery |
When combination weighing may be stronger
- The product forms stable individual portions
- Output and target control justify multiple weigh heads
- The product can distribute evenly without excessive damage
- The downstream packer can accept the planned discharge rate
When linear weighing may be stronger
- The required output is moderate
- The target range or pack format suits one or several lanes
- Simple access and operation are priorities
- The product feeds predictably through coarse and fine control
Controlled comparison
Use one trial brief for both technologies.
Supply the same product batch, target weights, pack, output and acceptance criteria. Record individual weights, mean, range, giveaway, rejects, product damage, stops, cleaning and changeover. If the machines are tested under different conditions, the comparison will not support a reliable buying decision.
Technology review
Ask Lancing to compare the routes around your product and pack.
The review can identify the likely technology, the sample required and the conditions that should be measured before final specification.
Compare the optionsBuyer questions
Frequently asked questions about this application.
Is a multihead weigher always more accurate than a linear weigher?
No universal claim is appropriate. The result depends on the product, target, feed stability, machine configuration and test conditions.
Which machine is better for high output?
Combination weighing can support high cycle demand where the product and downstream packer allow it, but sustainable finished-pack output must be proven.
Which route is easier to clean?
The answer depends on the number of contact parts, access, product and cleaning method. A linear system may have fewer hoppers, while a multihead system may use tool-free removable parts.
How should suppliers be compared?
Use the same product batch, target, pack, test duration and acceptance criteria and retain the full weight and stoppage data.
Related guidance
All guides