Classifying a Product by Viscosity, Density, Flowability, Particle Size, Abrasiveness and Aeration Before Shortlisting Filling and Dosing Principles

Start with the product property sheet, not the machine name

Buyers are advised to define the product's flow characteristics — free-flowing powder, sticky paste, chunky solid, liquid . Together with target output rate and bag style before contacting manufacturers, because those three factors narrow machine type faster than any other specification²¹.

Product characteristics such as viscosity for liquids, shape, weight, fragility and temperature sensitivity sit alongside throughput, changeover frequency, footprint, automation level, compliance and total cost of ownership in the standard selection criteria list⁹.

The practical consequence for you is that a property sheet written before the first supplier call turns the enquiry from "what fillers do you make" into "which of these principles passes my product". Viscosity is the clearest example of why the order matters.

Example viscosity bands are published per cosmetic product category, from 500 cP to 120,000 cP, each with a recommended filler type²². And pump technologies carry their own example envelopes, such as a progressing cavity range of 1 to 3,000,000 mPa·s¹⁷.

Those figures are reference points for framing your own specification, not a substitute for measuring your product. No source in this set establishes a mandatory test method, shear rate, or whether your product is Newtonian or shear-thinning, so state the method and temperature you used on the sheet itself.

If you are still deciding which dosing principle family to compare, the overview in How to Choose a Filling Machine sets out the matching logic between product, container and line.

Rule out principles whose published particle-size boundary is smaller than your largest particle

Published particle-size boundaries exist only as example, model-specific figures, so treat each one as a check to run against the named model rather than a limit for the whole pump class¹⁷.

The table below lists the boundaries that appear in the evidence; anything your largest particle or cube exceeds is a candidate for elimination before you request a quotation.

Match the viscosity band and filling challenge to a filler type, and record the temperature

Cosmetic product categories are mapped to typical viscosity bands, filling challenges such as foaming, stringy flow, shear sensitivity, aeration damage and abrasive particulates. And recommended filler types including peristaltic, gear, servo piston, heated piston and twin-screw pump²².

That mapping is the closest thing in this evidence set to a classification aid, and it works as a reference table rather than a rule for your product.

A toning gel sits in the 500–3,000 cP band with foaming tendency listed as its challenge, while a face cream sits at 15,000–80,000 cP with shear sensitivity and aeration damage listed instead²². The challenges differ by band, and so does the recommended filler type.

On the pump side, the envelopes are not directly comparable. A progressing cavity range is published as 1 to 3,000,000 mPa·s across the range, which the source notes is range-wide capability rather than every hygienic dosing model's envelope¹⁷.

A peristaltic hose pump range is described for high-viscosity and solids-bearing service, and the same source explicitly rejects a universal 10,000 cP ceiling or a soft-particles-only rule¹⁷. One gives a figure, the other refuses to; you cannot read them as the same kind of claim.

Because viscosity is temperature-dependent for emulsions, record the value at the temperature the product will actually be filled at, and write the test method and shear rate next to it. No source here establishes which method or shear rate to use, so the number is only as useful as the conditions you attach to it.

Where the product is a cosmetic emulsion or gel with temperature-dependent viscosity, the recommended filler type changes with the band . Servo piston or rotary pump for a body lotion, heated piston or twin-screw for a body butter²².

Identify which wear parts your product's abrasiveness attacks

Abrasiveness is a recognised selection factor, and the mitigation named in the evidence is specific: particulates such as keratin in a hair gel cause abrasive wear on seals. And a piston filler with abrasion-resistant seals is the recommended response²².

For precision gear pumps, the check list is compatibility, abrasiveness, gear clearance and hard solids¹⁷. Hard, abrasive inclusions such as seeds, crystalline chemical solids and mineral slurries are described as scratching cylinder walls, scoring valve seats and compromising shut-off seals.

Which points to hardened stainless steel contact paths, elastomeric valve seats and generous internal clearances¹⁷. What the sources do not give you is a classification scheme.

There is no abrasiveness grade, no scale, and no complete map of which wear parts a given product attacks. The EHEDG guideline catalogue does carry categories for elastomeric seals, mechanical seals, pumps, valves and dry materials handling⁴.

Which tells you the component families exist as documented subjects, but it does not tell you which of them your product will wear. Ask the supplier to name the wear parts in their design that your product contacts, and to state the seal and contact-path material they propose for it.

Set the fill accuracy target and the error-limit framework before you ask for a speed figure

For automatic gravimetric filling, error limits and minimum fill are calculated from the fill value, the in-service maximum permissible deviation and a class factor. And the zero or tare setting error adds directly to the fill error¹.

Where a fill value can be preset, the maximum permissible preset value error is 0.25 of the maximum permissible deviation³. Particle mass correction applies when the reference particle mass exceeds 0.1 of the maximum permissible in-service deviation.

And the values are then increased by 1.5 times the reference particle mass, capped at the class factor times 9%³. OIML R 61-2 works this through for a 2,000 g fill, arriving at an error limit of 3.75 g¹.

Use the framework to state your own accuracy requirement in grams or millilitres, and note that instruments verified with particle mass correction are not suitable for fills that must comply with OIML R 87³. Then ask for the speed figure in the right form.

Buyers should request documented specifications in writing, including tested output rates on the actual product rather than the manufacturer's rated maximum speed on an ideal test material²⁴.

A rated speed achieved on a test material tells you little about your product, so make the tested rate on your product a line item in the quotation.

Changeover, tooling and cleaning checks to put in the RFQ

Changeover time and tooling are recognised selection criteria, and changeover downtime carries a production cost because food processors work to short shelf-life windows¹³²⁴. One source reports that machines in the 10–30 cases/min bracket typically feature quick-changeover tooling and HMI recipe management allowing SKU switching in under 15 minutes⁷.

That is a segment-specific observation, not a target for your line. Use the checks below to make the supplier commit in writing.

• ✓State the number of SKUs and the format changes per shift on the property sheet
• ✓Ask for the documented changeover time per format change, not a catalogue figure
• ✓Ask which tooling is included in the base price and which is a priced option
• ✓Ask how the control system stores and recalls recipes for each SKU
• ✓Ask what cleaning access the design gives around the dosing path and seals

State the container format, fill range and product grade, then verify the principle with the supplier

Container format, fill range and product grade belong on the property sheet because they constrain the filling principle as much as the product does. But no source in this set ties a container format or a product grade — food, pharma, cosmetic, chemical — to a specific filling principle.

Product characteristics including viscosity, shape, weight, fragility and temperature sensitivity are listed as core selection criteria⁹, and that is as far as the evidence goes on the link. So treat the container and grade as inputs you supply and the principle as something the supplier must justify against them.

Ask which filling principle they propose for your container and fill range, and ask them to state the reason. If the answer is a machine name rather than a principle, the property sheet has not been used yet.

Where the published boundaries disagree, and what to verify before relying on a figure

The published boundaries come from different kinds of source and do not line up, so the honest reading is that each figure belongs to the model or rotor it was published for.

The table sets the two sides side by side; the last column tells you what to confirm before you use either number in a specification.

What to confirm before you order

• Ask the supplier for model-specific evidence and record the condition that would change your buying decision.
• Ask the supplier for model-specific evidence and record the condition that would change your buying decision.
• Ask the supplier for model-specific evidence and record the condition that would change your buying decision.
• Ask the supplier for model-specific evidence and record the condition that would change your buying decision.
• Ask the supplier for model-specific evidence and record the condition that would change your buying decision.
• Ask the supplier for model-specific evidence and record the condition that would change your buying decision.
• Ask the supplier for model-specific evidence and record the condition that would change your buying decision.
• Ask the supplier for model-specific evidence and record the condition that would change your buying decision.
• Ask the supplier for model-specific evidence and record the condition that would change your buying decision.