Rubber

Introduction to Rubber Material Testing Services

Rubber products are a fundamental component of modern infrastructure, spanning from everyday consumer goods to highly specialised applications in the aerospace, medical, automotive, and industrial manufacturing sectors. The utility of these materials is predicated not merely on their functional design but also on the need for consistent, reliable performance across diverse operational environments. Ensuring such performance standards requires implementing rigorous, precise testing protocols.

Infinita Lab provides an extensive suite of rubber testing services designed to yield critical data regarding material integrity, safety, and operational reliability. Our technical expertise extends to various grades of polymeric and elastomeric materials serving multiple industries, including automotive, aerospace, packaging, consumer products, and medical instrumentation. Utilising advanced analytical instrumentation, such as FTIR, GC/MS, GPC, Optical Microscopy, and SEM/EDS, our facilities are equipped to identify contaminants, perform detailed compositional and raw material analyses, investigate material failures, and evaluate degradation factors such as discolouration, odour issues, or the loss of elastic properties.

Our Rubber Testing Services

Mechanical & Tensile Testing

Mechanical testing determines the strength, stiffness, and endurance of rubber under various load conditions – including tension, compression, and bending. By simulating actual service stresses, mechanical testing ensures that rubber components will perform reliably in automotive seals, industrial hoses, medical devices, and consumer goods without deformation or premature failure.

Relevant ASTM Standards:

• ASTM D412 – Tensile stress-strain and set testing for vulcanised rubber and thermoplastic elastomers, measuring tensile strength, ultimate elongation, modulus at 100/200/300%, and tensile set – the primary mechanical characterisation test for rubber compound qualification across automotive, industrial, and medical applications. 
• ASTM D2240 – Shore hardness testing measures the surface resistance to indentation in rubber and elastomeric materials and is used for rapid production screening and material comparison across compound families.
• ASTM D1415 – International Rubber Hardness Degree (IRHD) testing provides a method for measuring the hardness of thermoplastics or vulcanised rubber samples by determining the penetration depth of a rigid ball into the rubber surface.
• ASTM D2990 – Creep and stress relaxation testing, measuring time-dependent deformation of rubber and elastomeric materials under sustained compressive or tensile load – critical for long-term sealing and load-bearing applications.

Compression Set & Force Decay Testing

Compression set is one of the most critical performance parameters for rubber seals, gaskets, and O-rings. It measures the permanent deformation retained by an elastomeric material after sustained compression – directly determining whether a seal will maintain contact stress and sealing integrity throughout its service life.

Relevant ASTM Standards:

• ASTM D395 (Method B) – Compression set testing under constant deflection conditions, the most widely specified test for rubber seals, O-rings, and gaskets. The specimen is compressed to 25% deflection at specified temperatures and durations, and the percentage of permanent set after recovery is calculated; a value of 0% indicates perfect elastic recovery.
• ASTM D6147 – Determination of force decay (stress relaxation) in vulcanised rubber and thermoplastic elastomers in compression, providing a controlled assessment of the loss of sealing contact stress over time under constant compressive deflection.

Tear Strength Testing

Tear strength testing evaluates a rubber material’s resistance to the initiation and propagation of cuts or tears under tensile loading. This is critical for rubber products subjected to cutting, abrasion, or edge-loading in service, such as diaphragms, belts, boots, and flexible membranes.

Relevant ASTM Standards:

• ASTM D624 – Tear strength testing for vulcanised rubber and thermoplastic elastomers, measuring resistance to the formation (tear initiation) and expansion (tear propagation) of a tear using die-cut specimens pulled to failure in a universal testing machine.

Heat Ageing & Thermal Degradation Testing

Rubber materials used in automotive, industrial, and aerospace applications are routinely exposed to elevated temperatures throughout their service life. Heat ageing testing evaluates the long-term thermal stability of rubber compounds and predicts their retention of performance over extended service at elevated temperatures.

Relevant ASTM Standards:

• ASTM D573 – Heat ageing testing for rubber in a circulating air oven, evaluating deterioration of mechanical properties (tensile strength, elongation, hardness) after defined time-temperature exposure cycles – the standard method for rubber thermal ageing assessment.
• ASTM D454 – Accelerated deterioration testing for vulcanised rubber under elevated temperature and high-pressure conditions, evaluating changes in physical properties following accelerated ageing in a bomb or pressure vessel.

Chemical & Fluid Resistance Testing

Rubber seals, hoses, gaskets, and diaphragms are exposed to oils, fuels, solvents, hydraulic fluids, coolants, and other aggressive chemicals throughout their service life. Chemical and fluid resistance testing evaluates how exposure to these liquids affects the rubber’s physical properties, ensuring that material selection and compound development decisions are based on verified performance data.

Relevant ASTM Standards:

• ASTM D471 – Effect of liquids on rubber properties testing, exposing rubber specimens to defined reference oils, fuels, hydraulic fluids, coolants, solvents, and acids under controlled temperature and time conditions, then measuring changes in volume, mass, hardness, tensile strength, and elongation relative to the pre-exposure baseline.
• ASTM D543 – Chemical resistance testing for rubber and elastomeric materials by immersion in reactive chemicals, evaluating mass change, dimensional change, and property retention when exposed to acids, bases, and solvents.

Ozone & Environmental Resistance Testing

Rubber materials used in outdoor, automotive, and industrial applications are susceptible to surface cracking caused by ozone attack. Ozone resistance testing evaluates the rubber’s ability to resist cracking under controlled ozone concentration and tensile strain conditions, providing quality control and compound development data for rubber used in cable jackets, automotive seals, and outdoor components.

Relevant ASTM Standards:

• ASTM D1149 – Ozone resistance testing for rubber, elastomers, and polymer products, evaluating static and dynamic ozone cracking resistance by exposing strained specimens to a controlled ozone atmosphere – the standard method for automotive seals, cable jackets, and outdoor rubber applications.

Cellular & Sponge Rubber Testing

Flexible cellular rubber and sponge materials are widely used in automotive weatherseals, HVAC sealing, industrial vibration damping, and packaging. Testing ensures that cellular rubber products meet the compression, deflection, and physical property requirements of their intended application.

Relevant ASTM Standards:

• ASTM D1056 – Flexible cellular rubber and sponge material testing, evaluating compression-deflection behaviour, density, water absorption, and oil resistance of open-cell and closed-cell sponge rubber materials for automotive, industrial, and construction applications.

Compositional Analysis & Chemical Characterisation

Rubber compositional analysis identifies the constituent components of a rubber compound – polymer type, carbon black content, oil and plasticiser level, filler and ash content – supporting quality control, failure analysis, deformulation, and compound identification across all rubber families, including NR, SBR, NBR, EPDM, silicone, and FKM.

Relevant ASTM Standards:

• ASTM D6370 – Rubber compositional analysis by thermogravimetric analysis (TGA), determining the oil/plasticizer, polymer, carbon black, and ash (filler) contents of vulcanised rubber and thermoplastic elastomers – the standard method for compound identification, quality control, and failure analysis.
• ASTM D297 – Chemical analysis of rubber products, determining rubber content by subtracting total non-rubber ingredients from 100% – applies to natural rubber (NR), isoprene rubber (IR), styrene-butadiene rubber (SBR), and butadiene rubber (BR) products.
• ASTM E1131 – Thermogravimetric Analysis (TGA) for compositional analysis of rubber materials, covering decomposition onset temperature, thermal stability, and filler quantification as a complement to ASTM D6370.

Thermal Analysis of Rubber Materials

Thermal analysis of rubber compounds determines melting and glass-transition temperatures, thermal stability, cure state, and material identity, supporting both incoming material quality control and formulation development for new rubber compounds.

Relevant ASTM Standards:

• ASTM D3418 – Differential Scanning Calorimetry (DSC) for rubber and elastomeric materials, measuring glass transition temperature (Tg), melting point, crystallisation behaviour, and oxidative induction time (OIT) for material identification and thermal characterisation.
• ASTM D6370 – TGA for thermal compositional analysis of rubber, providing a sequential decomposition profile that separates oil/plasticizer, polymer, carbon black, and inorganic filler components.
• ASTM E1640 – Dynamic Mechanical Analysis (DMA) measures the storage modulus, loss modulus, and tan delta versus temperature for rubber and elastomeric materials, enabling the precise determination of the glass transition temperature and viscoelastic stiffness profiling across the service temperature range.

Electrical Properties Testing for Rubber

Rubber materials are widely used as electrical insulation, cable jackets, and dielectric components in power cables, automotive wiring, and electronic assemblies. Electrical testing verifies dielectric strength, permittivity, and resistivity to ensure safe and reliable electrical performance of rubber insulation.

Relevant ASTM Standards:

• ASTM D149 – Dielectric strength testing for rubber and elastomeric insulation materials, measuring the maximum voltage before electrical breakdown – the fundamental safety test for rubber used in electrical insulation applications.
• ASTM D257 – Volume and surface resistivity testing for rubber insulating and anti-static materials to ensure adequate electrical isolation performance.
• ASTM D150 – Dielectric constant and dissipation factor testing for rubber electrical insulation materials used in capacitive and high-frequency electronic applications.