Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D502-89 – Standard Test Method Technical Guide
📜 Scope and Significance
This test method, designated D502-89 (Reapproved 2023), covers the determination of the particle size of soaps and other detergents by hand sieving and machine sieving methods. The values stated in SI units are to be regarded as standard. This test method assures that the particle size of soaps and detergents conforms to specifications having to do with density and packaging, among others. It also offers a means of controlling the amount of potentially hazardous very low particle size material, thereby contributing to safety and quality control.
⚙️ Test Procedure and Sieve Specifications
The sieves used in this test method must conform to Specification E11 for woven wire test sieve cloth. The standard nest of sieves consists of a No. 12 (1700 µm), No. 40 (425 µm), and a No. 100 (150 µm) sieve. Other size sieves may be used as required by individual specifications.
| 🟦 Sieve Number | 📏 Opening Size (µm) | 🎯 Typical Use |
|---|---|---|
| No. 12 | 1700 | Top sieve for large particles |
| No. 40 | 425 | Medium particle retention |
| No. 100 | 150 | Fine particle retention |
For the hand-sieving method, a 100 g ± 0.1 g well-mixed sample is transferred to the top sieve. The sieves are shaken by hand with occasional tapping until the portion passing through the bottom sieve is less than 0.1 g/min of shaking. The portions retained on each sieve and the portion passing the smallest sieve are carefully weighed. Duplicate determinations are made and averaged.
For the machine-sieving method, the same sample weight is used, and the nest of sieves is placed in a mechanically operated sieve shaker for 10 minutes. After shaking, the portions retained on each sieve and the portion passing the smallest sieve are weighed.
| 🔧 Method | ⏱️ Duration | ⚡ Sample Weight | 🧼 Sieve Nest |
|---|---|---|---|
| Hand-Sieving | Until <0.1 g/min passes | 100 g ± 0.1 g | No. 12, 40, 100 |
| Machine-Sieving | 10 minutes | 100 g ± 0.1 g | No. 12, 40, 100 |
📊 Key Measured Properties and Results
The key measured properties are the mass fractions retained on each sieve and the mass passing the smallest sieve. These measurements allow the determination of the particle size distribution, which is critical for ensuring compliance with specifications for density, packaging, and safety. The average of duplicate tests is used in calculations to improve precision.
💡 Tip: Ensure all sieves are clean and dry before use to avoid contamination and inaccurate results. Use a camel’s hair brush to transfer material between sieves.
✅ Safety Note: The test method helps control potentially hazardous very low particle size material. Always review Material Safety Data Sheets for reagents and materials before use.
❓ Frequently Asked Questions
🔍 What is the purpose of the D502-89 standard?
The standard provides a test method for determining the particle size of soaps and detergents using hand sieving and machine sieving methods, ensuring conformance to specifications for density and packaging.
💡 What sieves are required for the standard test?
The standard requires a nest of sieves consisting of No. 12 (1700 µm), No. 40 (425 µm), and No. 100 (150 µm) sieves, conforming to Specification E11. Other sieves may be used as needed.
⚡ How is the sample prepared for sieving?
A 100 g ± 0.1 g well-mixed sample is transferred to the top sieve without previous drying. For soaps, sample according to Test Methods D460, and for other detergents, according to Test Methods D501.
📌 What is the difference between hand-sieving and machine-sieving?
Hand-sieving involves manual shaking until the passage through the bottom sieve is less than 0.1 g/min, while machine-sieving uses a mechanical shaker for a fixed duration of 10 minutes.