What Is Low Temperature?
Low temperature properties test is a group of experiments in which the cold behavior of the elastomer is determined by methods such as brittleness temperature (ISO 812 / ASTM D2137), low temperature hardening (ISO 1432) or temperature recovery (TR test, ASTM D1329).
Purpose of Low Temperature
The aim is to verify that the elastomer maintains its flexibility and sealing ability at low service temperatures.
Which Products Is Low Temperature Applied To?
- Outdoor and cold climate seals
- Automotive rubber parts
- Cooling system hoses
- Low temperature gaskets and seals
In Which Sectors Is Low Temperature Used?
Standards Related to Low Temperature
- MIL-STD-810environmental engineering assessments and laboratory tests test
Low Temperature Conditions
- Crisp temperature
- The lowest temperature at which the samples do not break at the defined impact
- cooling environment
- Defined in the standard; liquid or gaseous medium
- Dwell time
- Time defined in the standard for the sample to equilibrate at the test temperature
- TR testi
- Temperatures recovered by the stretched sample while heating (TR10, TR30, TR70)
Equipment for Low Temperature
- Low temperature friability tester
- Cryostat or cooling bath
- TR test pattern
- Temperature measurement and recording system
Sample Requirements for Low Temperature
- Sample sizes must be defined in the standard
- The sample must be equilibrated at the test temperature for a defined period of time
- The cooling environment should not affect the sample
- The number of specimens is defined in the standard
Duration of Low Temperature
Typically 3–6 days.
Low Temperature Procedure
- 1Samples are prepared and conditioned.
- 2The target temperature is set and the samples are equilibrated.
- 3In the brittleness test, impact is applied and fracture is evaluated.
- 4The brittleness temperature is determined by gradually decreasing the temperature.
- 5In the TR experiment, the stretched sample is heated and the recovery temperatures are read.
- 6Results are reported.
Low Temperature Acceptance Criteria
The acceptance criterion is the maximum friability temperature or TR10 value given in the specification.
Evaluation of Results
Crisp temperature is not a serving temperature limit; is the impact resistance threshold. For the sealing of gaskets in cold weather, TR test and low temperature compression set should be evaluated together.
Low Temperature Report
- Standard and method applied
- Test temperatures and holding times
- Sample dimensions
- Brittleness temperature or TR values
- Assessment
Accreditation
EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.
Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Regulations
- Automotive and cold climate product specifications
Rubber Testing — What Does This Testing Field Cover?
The section below describes the field that the Low Temperature test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.
Rubber testing determines the mechanical behaviour of an elastomer and its resistance to environmental effects. Elastomers are assessed with a different logic from metals and plastics: the real question is not strength but ELASTIC RECOVERY and ageing behaviour.
The function of an elastomer is usually to deform and return: a gasket is compressed and provides a seal, a mount absorbs vibration, a hose expands under pressure. What is measured in the field is therefore not "how many newtons does it withstand" but "how far does it recover after deformation, and how long does it keep doing so".
COMPRESSION SET is therefore the most decisive measurement in the field. If a gasket cannot recover after being held compressed for a long period, it has lost its sealing function even though it has not torn at all. This measurement is made together with temperature, because permanent set increases rapidly with temperature.
Hardness is the most common measurement in the field, using the Shore A and IRHD scales. It is fast and practical but does not define the material on its own: two different compounds of the same hardness can show completely different ageing and fluid resistance. Hardness is valuable in monitoring compound consistency.
On the environmental resistance side, hot air ageing, swelling in fluids, ozone cracking and low temperature behaviour are examined. FLUID RESISTANCE is particularly critical: the same elastomer behaves differently in fuel, oil, coolant and brake fluid — swelling in one, shrinking in another, hardening in a third. The material is therefore tested with the actual fluid it will contact and at the actual temperature.
Ozone cracking is a silent cause of failure in parts used outdoors. Low concentrations of ozone in the atmosphere create surface cracks in unsaturated elastomers under strain; the part cracks while appearing to carry no load at all. An ozone chamber accelerates and reveals this behaviour.
Low temperature behaviour is the second silent risk. As an elastomer approaches its glass transition temperature it loses elasticity and behaves like a rigid plastic; a gasket starts to leak in the cold. Low temperature recovery and brittleness tests establish this limit.
A change of compound is not a silent change in this family. When filler content, plasticiser or the vulcanisation system changes, mechanical properties and fluid resistance shift together; verification is repeated.
Method groups in this field
Mechanical
Tensile stress-strain properties, tear strength, abrasion (rotating drum and Pico), fatigue and tear propagation.
Hardness
Shore A and IRHD indentation hardness; a rapid indicator of compound consistency.
Permanent deformation
Compression set and stress relaxation; decisive for sealing components.
Fluid resistance
Swelling in fuel, oil, coolant and chemicals, change in mass and volume, loss of hardness and strength.
Ageing
Hot air ageing, ozone cracking, the effects of UV and humidity.
Low temperature
Low temperature recovery, brittleness temperature and flexibility measurements.
Commonly confused in this field
- Hardness does not define the material; two compounds of the same hardness can show different ageing and fluid resistance.
- Fluid resistance must be tested with the actual fluid and the actual temperature; a general claim of oil resistance is insufficient.
- Without measuring compression set, no decision can be made about sealing life.
- Ozone cracking occurs under strain; a test with an unstrained specimen does not show the real risk.
- A change of compound requires verification to be repeated; a supplier may change its compound silently.
- A gasket whose low temperature behaviour is not stated produces unexpected leaks in cold climates.
Which decisions these results support
- Material selection for gaskets and sealing components
- Automotive and industrial component approval
- Verification of a compound change
- Root cause analysis of field leaks and cracking
- Declaration of the operating temperature range and fluid compatibility
Related Tests
Frequently Asked Questions About Low Temperature
According to which standard is Low Temperature made?
Low Temperature is executed in scope ISO 812 (brittleness temperature), ISO 1432 (low temperature hardening), ASTM D2137, ASTM D1329 (TR testi) and MIL-STD-810. The limit values and acceptance criteria to be applied are defined in the product standard; The version valid for your product is confirmed in writing at the offer stage.
Which products does Low Temperature apply to?
Mainly applied to Outdoor and cold climate seals, Automotive rubber parts, Cooling system hoses and Low temperature gaskets and seals. Whether your product is included in the scope is determined by examining its technical specifications and intended use.
Under what conditions is Low Temperature done?
The determining parameters are: Crisp temperature — The lowest temperature at which the samples do not break at the defined impact, cooling environment — Defined in the standard; liquid or gaseous medium and Dwell time — Time defined in the standard for the sample to equilibrate at the test temperature. The full terms are in the "Test Conditions" section on the page and vary depending on the product standard.
What kind of sample is needed for Low Temperature?
Sample sizes must be defined in the standard, The sample must be equilibrated at the test temperature for a defined period of time and The cooling environment should not affect the sample. The number of samples is determined according to the product standard and the scope to be reported.
How long does Low Temperature take?
Typically 3–6 days. This duration belongs to the experiment itself; sample preparation, queuing and reporting are also evaluated. A realistic schedule for your product is given in the offer.
What is the Low Temperature result called "appropriate"?
The acceptance criterion is the maximum friability temperature or TR10 value given in the specification.