Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D269-97 – Standard Test Method Technical Guide
📌 Scope and Significance
This test method, designated D269-97 (Reapproved 2020), provides a standardized procedure for determining the amount of insoluble matter in rosin and rosin derivatives, as defined in Terminology D804. The values stated in SI units are regarded as the standard. This method is crucial for identifying contaminants such as sand, dirt, or bark in gum and wood rosin, as well as insoluble residues in derivatives. It is based on the solubility of rosin in organic solvents and is especially useful for internal quality control.
⚙️ Apparatus and Reagents
The apparatus required includes an 800 mL beaker, a magnetic stirring hot plate with a PTFE stir bar, a precut stainless steel screen (325 mesh, 44-µm openings) conforming to Specification E11, a two-piece filter apparatus, an analytical balance capable of weighing to 0.0001 g, laboratory tweezers, and a forced draft oven. Reagents include clean toluene, hexane, mineral spirits, or other suitable solvents as agreed upon.
| 🔧 Apparatus Component | 📏 Specification |
|---|---|
| Screen Mesh Size | 325 mesh |
| Wire Diameter | 0.0014 in |
| Opening Size | 44 µm |
| Analytical Balance Precision | 0.0001 g |
📋 Test Procedure
The procedure begins by rinsing the precut screen with solvent, then drying it at 105 to 110°C for 30 minutes. After cooling in a desiccator, the screen is weighed to the nearest 0.0001 g and secured in the filter apparatus. A 100 ± 0.1 g sample of freshly powdered material is weighed into an 800 mL beaker, and 150 mL of solvent is added. The mixture is heated and stirred until complete dissolution, avoiding boiling. The solution is then filtered through the prepared screen, and the beaker and screen are rinsed with solvent to collect all insoluble matter. The screen with residue is dried at 105 to 110°C for 30 minutes, cooled, and weighed. The increase in weight corresponds to the insoluble matter content.
| ⚡ Procedure Parameter | 📐 Value |
|---|---|
| Sample Weight | 100 ± 0.1 g |
| Solvent Volume | 150 mL |
| Drying Temperature | 105 to 110°C |
| Drying Time | 30 min |
💡 Note: Always use laboratory tweezers when handling the precut screen to avoid contamination and ensure accurate weighing results.
⚠️ Warning: This standard does not address all safety concerns. Users should implement appropriate safety practices when working with solvents and high temperatures.
❓ Frequently Asked Questions
🔍 What is the purpose of ASTM D269-97?
This test method is used to determine the amount of insoluble matter in rosin and rosin derivatives, such as sand, dirt, or bark contaminants, for quality control purposes.
💡 Which solvents are acceptable for this test?
Acceptable solvents include clean toluene, hexane, mineral spirits, or any suitable solvent agreed upon between the customer and supplier.
⚡ How should the filter screen be prepared?
The screen must be rinsed with solvent, dried at 105-110°C for 30 minutes, cooled in a desiccator, and weighed to 0.0001 g before use.
📌 Why is the test method significant for rosin derivatives?
It ensures that insoluble material from raw materials or production processes is kept to a minimum, aiding in internal quality control.