Large-port piston route
A piston can deliver a defined displaced volume, but the inlet valve, outlet valve, cylinder and nozzle must pass the inclusions without cutting or trapping them. Suction behaviour and hopper feed are part of the test.
Product-path selection
How do you fill liquids and pastes containing particles?
Products containing pieces, fibres, seeds, herbs or suspended solids must pass through the complete feed, valve and nozzle path without blocking, separating or unacceptable damage. The selection depends on the worst credible inclusion and how consistently it is distributed.
- Measure the largest credible inclusion
- Protect distribution and product condition
- Inspect total quantity and solids content separately
Direct answer
Size the complete product path around the difficult inclusion
A filling machine for products with particles must move both the carrier and the inclusions through the hopper, pump or piston, valves, hoses and nozzle. The controlling specification is normally the largest credible particle or cluster, not the average texture. A representative trial should prove dose quantity, particle distribution, product condition, shut-off and cleaning over the complete batch state.
“Contains particles” is not enough information. Record particle dimensions, shape, fragility, concentration, density relative to the carrier, settling rate and whether inclusions change during cooking, mixing, storage or pumping.
Define the product
Six product properties that determine the filling route
| Property | How to describe it | Machine effect |
|---|---|---|
| Maximum particle size | Length, width, thickness and occasional clusters | Sets minimum passages and affects valve/nozzle selection. |
| Particle shape | Round, fibrous, leaf, flake, irregular or string-like | Changes bridging, orientation and cutting risk. |
| Fragility | Acceptable breakage, crushing or surface damage | Limits shear, clearances and valve movement. |
| Concentration | Typical and worst solids content across the batch | Affects distribution, feed consistency and dose variation. |
| Density and settling | Whether pieces float, suspend or settle and how quickly | Determines hopper geometry, agitation and refill control. |
| Carrier behaviour | Viscosity, temperature, stringing, foam and lubrication | Influences suction, discharge, cut-off and cleaning. |
Compare routes
Machine principles to test with particulate products
Suitable pump route
A pump may support continuous feed or gentler transfer for some products. Pump type, speed, shear, priming, pressure, reversible recovery and cleanability must be assessed with the real formulation.
Alternative separation or dosing process
If the pieces cannot be distributed reliably in one product path, a separate solids and liquid dosing process or another packaging method may be more appropriate. That decision should be made from pack-quality evidence, not only cycle time.
Representative trial
How to test a product that contains pieces
- Use an unscreened sample.Bring normal production variation, including the largest credible inclusions and the lowest/highest solids concentration.
- Replicate preparation.Record mixing, cooking, temperature, rest time and transfer method because each can change the product.
- Prime without selective loss.Check whether the feed system retains pieces or sends a solids-rich first portion to the filler.
- Inspect repeated packs.Measure total quantity and the agreed indicator of particle distribution or product condition.
- Challenge low level and refill.Confirm that the final part of the batch and replenishment remain representative.
- Clean and inspect the path.Open the specified components and check for trapped pieces, damage and inaccessible residues.
Buyer questions
Common questions about filling products with particles
Which filling method is suitable for products containing particles?
A product with particles often needs a positive-displacement or pump route with valves, hoses and nozzles sized for the largest credible inclusion. A piston may be suitable for some sauces or pastes, while other products may need a gentler pump or different feed arrangement. The route must be proven with the actual particle size, concentration, fragility and carrier viscosity.
Do not rely on a catalogue viscosity band; the product pathway and valve action must physically pass the difficult inclusion.
Why is the largest particle more important than the average particle?
One oversized piece can bridge a valve, block a nozzle or prevent complete closure even when the average product appears easy to fill. Specify the largest credible length, width and shape, including occasional clusters, and test the worst production batch rather than a sieved demonstration sample.
Provide an unscreened production sample and describe how particle size varies between batches, storage time and temperature.
How can particle settling or separation be controlled?
The feed vessel may need gentle agitation, controlled recirculation or a short product path, but excessive movement can damage inclusions or introduce air. The objective is representative distribution at every dose. Compare the first, middle and final fills from the batch and inspect particle count or mass using an agreed method.
If agitation is used, define speed, direction, running time and low-level behaviour as part of the accepted recipe.
Can a filling machine damage product pieces?
Yes. Tight clearances, rapid valve movement, sharp changes in direction, high pump shear and narrow nozzles can cut or crush inclusions. Damage may also occur in the upstream transfer pump. Inspect the filled product, not only the dose weight, and compare it with the approved product condition.
Review the complete path from bulk vessel to nozzle because the filler cannot restore particles already damaged upstream.
How should fill accuracy be assessed when pieces vary between packs?
Separate the total quantity result from the distribution of inclusions. A pack can meet its total weight or volume while containing too few or too many pieces. Define whether acceptance concerns total quantity, piece distribution, solids-to-liquid ratio, visual appearance or all of these, then use a sampling method appropriate to the product.
Where a legal quantity declaration applies, retain a separate compliant measurement and record system for the packaged goods.
What makes particulate filling harder to clean and change over?
Pieces can remain in valve cavities, hose low points, manifolds and nozzle shut-off mechanisms. The design should provide access or validated flushing for every product-contact area. The changeover method must account for trapped inclusions, allergen or flavour carryover where relevant and safe removal of heavy or awkward tooling.
Cleaning evidence should cover disassembly, inspection, reassembly and the first acceptable pack after changeover.
Prepare the enquiry
Particulate-product information to provide
- Full product description and production temperature
- Largest credible particle dimensions, shape and fragility
- Typical and worst solids concentration
- Whether particles float, settle, cluster or change over time
- Fill range, container opening and required presentation
- Allowed product damage and pack-to-pack distribution criteria
- Cleaning, allergen and changeover requirements where relevant
- Enough unscreened product and packs for a full-path trial
Prove the full product path before specification
Lancing can review the actual inclusions, carrier, pack and quality criteria, then identify the filling routes and trial evidence needed.