ISO 1798 is an ISO test method used to determine tensile strength and elongation at break for flexible cellular polymeric materials (commonly flexible foams). It supports material qualification and comparative testing by pulling a test piece at a controlled, constant rate until rupture.
This standard is often specified when a foam’s tensile performance is tied to product durability, manufacturing consistency, or performance changes after conditioning or ageing. If you need help matching the correct edition and setup to a customer or internal requirement, talk with our team.
ISO 1798:2008 – Flexible cellular polymeric materials — Determination of tensile strength and elongation at break
ISO 1798:2008 describes a tensile test approach for flexible cellular polymeric materials where a specimen is extended at a constant rate until it breaks. The results are used to characterize strength and deformation behavior at rupture.
Document type: Test method (International Standard).
Quick Definition
ISO 1798 is used to pull a flexible cellular polymeric specimen in tension at a controlled rate to obtain tensile strength and elongation at break.
What This Standard Covers
This standard focuses on tensile loading of flexible cellular polymeric materials and the resulting properties at rupture.
Typical reported outputs: Tensile strength and elongation at break (based on extension to failure at a constant rate).
What it does not try to be: A full product specification or a durability/ageing standard by itself; it provides a method for generating tensile results that may be referenced by product requirements or other test plans.
Why This Standard Matters in Testing
Tensile strength and elongation at break are commonly used to compare foam formulations, monitor manufacturing drift, and document conformance to internal or customer requirements. For many flexible foams, tensile behavior is also used as a “health check” property when evaluating the impact of conditioning, process changes, or environmental exposure.
Practical caution: Tensile results for foams are sensitive to specimen preparation and gripping. Equipment and fixtures should be selected to minimize slippage and unintended tearing at the grips so failures represent the material, not the clamping method.
Common Materials, Product Types, or Applications Covered
ISO 1798 is most commonly used for flexible cellular polymeric materials such as flexible polymer foams used in cushioning, sealing, vibration control, and similar applications where tensile properties are specified or tracked.
Common use cases: Incoming material checks, formulation comparison, production quality control, and benchmarking tensile performance before/after conditioning steps specified by a program or contract requirement.
Common Test or Verification Workflow
Most labs apply ISO 1798 within a straightforward tensile workflow, then use the results for acceptance, comparison, or trend monitoring.
- Define the material/product to be tested and the required edition of ISO 1798 cited by the customer or internal specification.
- Prepare test pieces appropriate for tensile loading and mount them in a tensile fixture/grip set suitable for flexible foams.
- Pull the specimen at a constant rate until break and capture the needed force/extension data to calculate tensile strength and elongation at break.
- Report results with enough detail (machine, grips, and referenced edition) for repeatability across labs or production sites.
Equipment Commonly Used for This Standard
ISO 1798 typically points to a controlled tensile test setup capable of running a constant-rate extension-to-break test and capturing load and extension.
Common equipment: Universal testing machine (UTM) with appropriate load capacity and speed control; foam-appropriate grips or clamping fixtures; calibrated force measurement; extension measurement via crosshead displacement and/or an extensometer when appropriate for the material and setup.
Selection note for buyers: In foam tensile testing, the gripping approach is often the deciding factor for repeatable data. Many labs prioritize grip faces, jaw geometry, and alignment features to reduce slippage and grip-induced tearing.
How to Read This Designation or Revision
ISO 1798:2008 identifies the ISO standard number (1798) and the publication year of the cited edition (2008). When purchasing, quoting, or writing test reports, it is good practice to cite the full designation with the year to avoid edition mismatches.
Older editions exist and may be withdrawn, so equipment setup and reporting expectations should be aligned to the exact edition referenced in your customer or internal requirement.
Related Standards, Methods, or Frameworks when useful
ISO 1798 tensile results are frequently paired with other flexible-foam property tests when building a fuller material profile.
Often used alongside: ISO 2439 (indentation hardness of flexible cellular materials), ISO 1856 (compression set), and ISO 8067 (tear strength) where a program requires multiple mechanical properties for flexible foams.
Get help selecting a tensile test setup for ISO 1798
If you are outfitting a lab or upgrading grips and fixtures for flexible foam tensile testing, you can request a detailed quote for a UTM and gripping package matched to your material type and throughput.