Overview
ISO/TR 22007-5:2011 - Plastics - Determination of thermal conductivity and thermal diffusivity - Part 5 - documents the results of an interlaboratory comparison for measuring thermal conductivity (λ) and thermal diffusivity (α) of two poly(methyl methacrylate) (PMMA) materials. The report summarizes measurements made with transient, modulated and steady‑state techniques referenced in ISO 22007 parts 1–4 and additional ASTM methods. It presents method-specific apparatus, specimen preparation, procedures, individual laboratory data (Annexes B–F) and uncertainty/ repeatability analysis.
Key topics and technical requirements
- Materials tested: Sumipex cast PMMA (≈2 mm sheet) and an extrusion‑grade PMMA (≈3 mm sheet; pellets supplied).
- Measurement methods covered: Transient plane heat source (Hot Disk), laser flash, temperature wave analysis (TWA), transient line‑source probe, guarded heat flow meter and other transient/steady‑state techniques.
- Specimen preparation: Method‑dependent sample thickness and surface treatments (e.g., graphite/paint/sputter coatings) - important to meet thickness criteria for each method.
- Data analysis & calculations: Conversions between λ and α using ρCp (apparent volumetric heat capacity); laboratories calculated thermal properties from raw data and reported uncertainties.
- Uncertainty & repeatability: Expanded uncertainties (k = 2) estimated following the Guide to the Expression of Uncertainty in Measurement (GUM). Typical interlaboratory results were generally within approximately ±10% of the mean.
- Measurement practice issues identified:
- Ensure specimen thickness meets method criteria (may require machining).
- Account for material anisotropy (measurement geometry can capture bulk or directional properties).
- Include uncertainties from specific heat capacity (Cp) and density when converting between λ and α.
Applications and who uses this standard
- Thermal property laboratories conducting calibration, intercomparisons, or method validation.
- Polymer and PMMA manufacturers performing material characterization for product development and quality control.
- Thermal engineers and simulation specialists who need validated thermal conductivity/diffusivity data for thermal modeling of plastics.
- Standards developers and accreditation bodies using interlaboratory results to refine ISO 22007 parts 1–4 and measurement guidance.
- Researchers studying heat transport in polymers and seeking comparative method performance.
Related standards
- ISO 22007‑1 to ISO 22007‑4 (general principles, Hot Disk, temperature wave analysis, laser flash)
- ISO 472 (plastics - vocabulary)
- ISO 1183‑1, ISO 11357‑4 (density, heat capacity methods referenced)
- ASTM D5930, ASTM E1530 (line source & heat flow meter techniques)
- Guide to the Expression of Uncertainty in Measurement (GUM)
ISO/TR 22007-5:2011 is an informative technical report focused on interlaboratory performance, practical measurement issues, and uncertainty considerations for thermal characterization of PMMA using standardized thermal conductivity and diffusivity methods.