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Particle Size Distribution Test — Standard Operating Procedure & Record

1. Purpose & Scope

This procedure defines the method for determining the particle size distribution of paprika powder, flakes, and ground samples by mechanical sieve analysis. Particle size distribution affects dissolution rate, blending uniformity, and application performance (e.g., seasoning adhesion, extraction efficiency).

Scope: All paprika powder grades (40 mesh standard, custom mesh optional), flake grades (4–8 mesh), and ground whole-pod samples.

2. Equipment & Consumables

Item Specification Notes
Sieve Shaker Mechanical or electromagnetic Recommended: Retsch AS 200 or equivalent
Test Sieves 8-inch (200 mm) diameter, stainless steel Per ISO 3310-1 / ASTM E11
Required Sieve Stack (Powder) 20 mesh (840 µm), 40 mesh (420 µm), 60 mesh (250 µm), 80 mesh (177 µm), 100 mesh (149 µm), Pan
Required Sieve Stack (Flakes) 4 mesh (4.76 mm), 8 mesh (2.38 mm), 20 mesh (841 µm), Pan
Analytical Balance ±0.01 g precision Calibrated daily
Sample Splitter Riffle splitter for representative subsampling
Brush Soft-bristle, for sieve cleaning MUST not damage mesh
Timer / Stopwatch ±1 second resolution

3. Detailed Procedure — Step by Step

3.1 Sampling

  1. Obtain representative sample per Incoming Inspection Procedure.
  2. Reduce sample to ~100 g using riffle splitter for powders, or ~200 g for flakes.
  3. Record sample identification (batch, grade, product name).

3.2 Preparation

  1. Clean all sieves with soft brush — verify no blinding from previous use.
  2. Record weights of each empty sieve and the pan.
  3. Weigh the test sample to 100.0 ± 0.5 g for powder, 200.0 ± 0.5 g for flakes.
  4. Assemble sieve stack in ascending mesh order (coarsest on top → pan on bottom).

3.3 Sieving

  1. Place the weighed sample on the top sieve.
  2. Close the sieve stack with lid and secure on shaker.
  3. Set shaker amplitude to 2.0 mm (or equivalent for your model).
  4. Run shaker for 10 minutes ± 15 seconds.
  5. After sieving, carefully disassemble the stack. Weigh the material retained on each sieve and the pan.

3.4 Sieve Analysis Calculation

For each sieve: - % Retained = (Weight retained on sieve / Total sample weight) × 100 - Cumulative % Retained = Sum of % retained on this sieve + all coarser sieves above - Cumulative % Passing = 100 − Cumulative % Retained

3.5 Validation Check

Mass balance check: Sum of all weights retained (including pan) must equal 100% ± 1% of initial sample weight. If loss >1%, repeat the test.

4. Test Record Form

Lab Information
Sample ID
Product Name
Grade
Batch/Lot Number
Test Date
Operator

4.1 Equipment

Item Detail
Sieve Shaker Model
Shaker Duration 10 minutes
Shaker Amplitude
Initial Sample Weight (g) ______ g
Total Recovered Weight (g) ______ g (should be within 1% of initial)

4.2 Sieve Analysis Results — Powder Sample

Mesh Size Opening (µm) Weight Retained (g) % Retained Cumulative % Retained Cumulative % Passing
20 840
40 420
60 250
80 177
100 149
Pan —
Total 100.0%

4.3 Sieve Analysis Results — Flakes Sample

Mesh Size Opening (mm) Weight Retained (g) % Retained Cumulative % Retained Cumulative % Passing
4 4.76
8 2.38
20 0.841
Pan —
Total 100.0%

5. Specification Check

Powder Grades

Grade Specification Test Result Pass/Fail
All Powder Grades ≥95% passing through 40 mesh (420 µm)

Flake Grades

Grade Specification Test Result Pass/Fail
All Flake Grades Primary cut 4–8 mesh (2.4–4.8 mm)
All Flake Grades Fines (<20 mesh / 841 µm) ≤10%
All Flake Grades Oversize (>4 mesh / 4.76 mm) ≤5%

6. Acceptance Criteria & Decision Rules

Condition Action
Powder: ≥95% through 40 mesh PASS
Powder: 90–94.9% through 40 mesh HOLD — evaluate; may be acceptable if customer agrees
Powder: <90% through 40 mesh FAIL — re-sieve or re-mill
Flakes: Fines ≤10% PASS
Flakes: Fines 10–15% HOLD — customer acceptance required
Flakes: Fines >15% FAIL — re-screen to remove fines
Flakes: Oversize >5% FAIL — re-screen or re-cut
Mass balance check failure (>1% loss) VOID — repeat test

7. Recording Requirements

  • Record sieve tare weights before each use.
  • Record all weights to 0.01 g.
  • Log operator name, date, shaker model, and run time for each test.
  • Results feed into the batch COA.
  • QC logbook entries must be signed and dated in ink.

8. Calibration & Verification

Frequency Activity Standard
Per use Visual check for sieve damage/blinding —
Quarterly Certified reference spheres / check sieves ASTM E11 calibration sieve
Annually Third-party sieve re-certification ISO 3310-1
Annually Balance calibration NIST-traceable weights

9. Troubleshooting

Symptom Probable Cause Corrective Action
Mass loss >1% Sample loss during transfer Use closed-top sieve stack; brush sides
Sieve blinding (material stuck in mesh) Overloading or sticky product Reduce sample weight; clean sieve with ultrasonic bath
Inconsistent results between runs Shaker time too short or amplitude incorrect Verify settings; repeat at 12 min
Fines % higher than expected Over-sieving time Reduce to 8 minutes and re-test
Oversize material present in powder Damaged sieve mesh Inspect mesh under light; replace if torn

10. Method References

  • ISO 2591-1 — Test Sieving — Methods using test sieves of woven wire cloth
  • ASTM E11 — Standard Specification for Woven Wire Test Sieve Cloth
  • ISO 3310-1 — Test sieves — Technical requirements and testing — Part 1: Test sieves of metal wire cloth
  • AOAC 965.22 — Sieve Analysis (for reference)

This document is part of the official technical documentation library for paprikabulk.com operated by Dinweys (Qingdao).Co.,Ltd. All rights reserved. For the latest version, visit paprikabulk.com.