ASTM D3835-24 PDF

Full title and description

Standard Test Method for Determination of Properties of Polymeric Materials by Means of a Capillary Rheometer — a test method that defines procedures and conditions for measuring melt flow and related rheological properties of polymeric materials using a capillary (or slit–die) rheometer. It provides instructions for instrument configuration, sample conditioning, test execution, and basic data reduction for melt viscosity, shear sensitivity, die‑swell, and thermal flow stability.

Abstract

This test method describes how to determine rheological properties of thermoplastic and other polymeric materials under processing‑relevant temperatures and shear rates using a capillary rheometer. Results include melt viscosity vs. shear rate, indications of shear or thermal instability, die‑swell behavior, and data useful for correlating material behavior with extrusion or molding processing conditions. The method is technically aligned with comparable international procedures (for example ISO 11443).

General information

• Status: Active / Current.
• Publication date: 2024 (issued/updated in 2024 — recorded update 29 August 2024).
• Publisher: ASTM International (formerly American Society for Testing and Materials).
• ICS / categories: 83.080.20 (Thermoplastic materials).
• Edition / version: D3835‑24 (2024 edition).
• Number of pages: 11.

Scope

This standard covers measurement of rheological properties of polymeric materials at temperatures and shear rates common to polymer processing. It specifies measurements of melt viscosity, melt viscosity sensitivity and stability with respect to temperature and dwell time, die‑swell ratio, and shear sensitivity during extrusion under constant rate or stress. The method is intended for both reinforced and unreinforced thermoplastics and may be applied for quality control, material comparison, and processing development.

Key topics and requirements

• Instrument setup and calibration (capillary geometry, entrance effects, temperature control).
• Sample conditioning, preheat and dwell time procedures to ensure reproducible melt state.
• Measurement of apparent shear viscosity across a range of shear rates relevant to processing.
• Corrections and data reduction methods (e.g., Bagley and Rabinowitsch corrections where applicable).
• Die‑swell (extrudate expansion) measurement and reporting.
• Procedures to detect and report shear and thermal instability or degradation during testing.
• Reporting requirements: test temperature(s), geometry, shear rate range, and any corrections applied.

Typical use and users

Used by polymer scientists, rheologists, materials and process engineers, QC/analytical laboratories, and instrument manufacturers. Typical applications include material characterization, quality control of incoming polymer batches, processing window development for extrusion and molding, and comparative evaluation of formulations or fillers (for example, assessing the effect of reinforcements or plasticizers on melt flow behavior).

Related standards

Closely related documents include ISO 11443 (fluidity determination with capillary and slit‑die rheometers) and ASTM D1238 (melt flow index) for single‑point melt flow comparisons; the standard is often used alongside other rheological and thermal test methods when characterizing polymer processing behavior. Planned revision work items for D3835‑24 have been recorded by the developing committee, indicating active maintenance of the test method.

Keywords

capillary rheometer, capillary rheometry, rheology, melt viscosity, shear rate, die swell, thermal flow stability, thermoplastics, polymer processing, viscosity vs. shear rate.

FAQ

Q: What is this standard?

A: ASTM D3835‑24 is a standardized test method that specifies how to measure rheological properties of polymeric materials using a capillary rheometer, reporting melt viscosity, shear sensitivity, die‑swell, and related parameters useful for processing and material evaluation.

Q: What does it cover?

A: It covers instrument configuration, sample handling, test procedures at processing‑relevant temperatures and shear rates, data reduction (including common corrections), and reporting of viscosity, die‑swell, and stability characteristics.

Q: Who typically uses it?

A: Polymer testing and R&D laboratories, quality control teams, rheologists, materials engineers, and equipment manufacturers use the method to characterize materials and support processing decisions.

Q: Is it current or superseded?

A: It is current (2024 edition, D3835‑24) and is maintained by ASTM Committee D20; revision work items have been recorded, indicating ongoing updates by the committee.

Q: Is it part of a series?

A: It is part of ASTM polymer testing practices and belongs to the D20 committee collection of plastics standards; it complements other rheology and melt‑flow standards rather than being a numbered sequential series.

Q: What are the key keywords?

A: Capillary rheometer, melt viscosity, rheology, die‑swell, shear sensitivity, thermal stability, thermoplastics.