Choose an MSG particle specification by defining the manufacturing task, obtaining a supplier's sieve distribution and testing a representative sample. The labels 20, 60 and 80 mesh can help organise an enquiry, but they do not establish every crystal's dimensions or prove suitability for your equipment. Compare documented offers against the same process requirements before selecting a grade for a bulk order.
1. Separate sieve openings from product dimensions
The Endecotts sieve catalogue lists these nominal openings for common US/ASTM E11 sieve references. The values describe sieve apertures; a commercial MSG specification must also define the tested particle-size distribution.
| US/ASTM sieve reference | Nominal opening | What an offer must still define |
|---|---|---|
| No. 20 | 850 micrometres | Required passing and retained fractions, with the test method |
| No. 60 | 250 micrometres | Required passing and retained fractions, with the test method |
| No. 80 | 180 micrometres | Required passing and retained fractions, with the test method |
Particle shape matters: elongated particles can pass through a sieve lengthwise, and the test conditions influence interpretation. RETSCH's sieve analysis guidance explains these limitations. A close-up image therefore cannot establish a batch's sieve distribution.
Ask suppliers which standard they mean whenever the offer says only mesh. Record the standard and nominal openings together, especially when comparing quotations prepared under different conventions. If the supplier cannot explain the stated grade, keep the enquiry open rather than translating an ambiguous label into a purchase specification yourself.
2. Start with the manufacturing question
If you are comparing 20- and 60-mesh MSG for a manufacturing process, first define what the change needs to achieve. It could be an existing particle specification, a dosing requirement or a formulation trial. A preference for a visually coarser or finer material is not an acceptance criterion unless that appearance has a defined role in your finished product.
Write one primary decision question and list the conditions that must remain comparable. For a dry blend, that may mean the same formula, mixer loading and sampling method. For a liquid process, it may mean the same addition stage and process settings. For automated dosing, it may mean the same feeder configuration and target addition.
Do not rank the three labels as universally better or worse. They are starting points for requests that need supplier confirmation. Current Fufeng availability, actual size distributions and the combination of grade with packing must be confirmed for the specific offer.
3. Use a decision worksheet to shortlist samples
Complete the following worksheet before requesting several samples. It keeps the shortlist tied to a measurable question and reduces the chance of testing materials that cannot be compared.
| Your starting point | Evidence to request | Decision to make |
|---|---|---|
| Existing approved material | Current specification, retained sample identity and supplier distribution | Can a candidate be compared against the established baseline? |
| New dry seasoning formula | Candidate distribution and a controlled blend trial | Which candidate meets the formula's agreed acceptance criteria? |
| Fine premix feeding route | Candidate distribution plus dosing and transfer records | Can the material complete the approved handling route? |
| Liquid seasoning process | Candidate identity and a trial under defined addition conditions | Does the material meet the plant's process and product criteria? |
| Supplier substitution | Batch-linked sample, analytical documents and comparison results | Is the proposed replacement equivalent within the approved scope? |
Shortlist only the candidates that answer the decision question and have adequate identity information. If the intended production material differs from the sample, ask what changed and whether another trial is needed. Never let an attractive photograph replace the evidence required by the worksheet.
4. Compare results under agreed conditions
Have quality define the particle test method and acceptance limits before results arrive. Ask for the complete relevant distribution rather than a single favourable fraction. Record how the sample was prepared and tested so that differences in method can be investigated before differences in material are assumed.
For a dry blend, compare the candidate and reference under matched mixing and sampling conditions. For feeding and transfer, record delivered quantities, retained material and operator interventions against the plant's acceptance criteria.
Record an outcome for each candidate: approved for the documented use, rejected with a reason, or pending specific evidence. Keep unresolved documentation and process deviations visible. A cheaper quote should not turn a pending technical result into an approval.
5. Write the final specification without ambiguity
The purchasing specification should identify the manufacturer and product, sieve standard, relevant size fractions and limits, agreed test method, sample approval reference, composition requirements and packing. State which changes require review. Attach the approved revision to the purchase request so the commercial team does not reduce the requirement back to a mesh name.