How to Conduct Tensile Strength Testing on Rubber and Plastic Materials?

Tensile strength is a key indicator measuring a rubber or plastic material's resistance to tensile failure. It directly determines the service life and safety performance of products in packaging, automotive, electronics, and other fields (e.g., plastic film rupture and rubber seal failure are both related to tensile properties). Standardized tensile testing provides reliable data support for material R&D and mass production.

Tensile strength testing simulates real-world stress scenarios by applying static, unidirectional, uniform-speed stretching to quantify a material's resistance to fracture. By applying incrementally increasing loads to standardized specimens, the load-deformation relationship is recorded to calculate key mechanical properties (tensile strength, elongation at break, elastic modulus, etc.), ultimately revealing the material's intrinsic characteristics.

Key Indicators:

1. Tensile Strength (Rm): Maximum stress (MPa) a specimen withstands before fracture. Formula: Rm = Maximum Load (Fm) / Original Cross-sectional Area (A₀)

2. Elongation at Break (A): Percentage of plastic elongation in the gauge section after fracture relative to the original gauge length, calculated as A = [(Post-fracture gauge length Lₙ - Original gauge length L₀)/L₀] × 100%

3. Modulus of Elasticity (E): Slope of the elastic section in the stress-strain curve, characterizing material stiffness

GB/T 1040-2025: Applicable to thermoplastics/thermosets and films

ISO 527-1:2019: Applicable to plastics and composites

ASTM D412-16: Applicable to vulcanized rubber/elastomers

ASTM D638: Applicable to tensile properties of plastics

1. Core Features

1.1 Core Requirements: Force accuracy ±0.25%, displacement accuracy ±0.04mm, adjustable tensile speed range 0.1-1000mm/min

1.2 Compatible Functions: Must support real-time stress-strain curve plotting, multi-standard presets (e.g., built-in GB/ISO/ASTM test programs)

1.3 Company Instrument Advantages: UTSTESTER Universal Testing Machines feature a 5000Hz high-speed data acquisition module, compatible with multiple industry standards. Precisely captures yield points and instantaneous peak forces of rubber/plastic materials. Supports Windows-based online software operation.

2. Auxiliary Equipment & Fixtures

2.1 Fixtures

Rubber materials: Pneumatic soft rubber grips, rubber wedge grips.

Plastic materials use wedge-type or flat-push grips with anti-slip design.

2.2 Deformation Measurement

Rubber materials use large-deformation extensometers (suitable for elongation ≤1000%)

Plastic materials use high-precision extensometers (essential for measuring elastic modulus)

1. Specimen Preparation Specifications: For plastics, prioritize dumbbell specimens of Type 1A/1B (thickness 4mm/2mm). For rubber, use ASTM D412 dumbbell specimens (thickness 1.3-3.3mm). For films, employ rectangular specimens measuring 150mm × 25mm (gauge length 50mm). 2. Equipment Inspection and Calibration: Prior to testing, inspect the H001N Universal Testing Machine to ensure all components function properly. Then configure appropriate test parameters (e.g., tensile speed) based on testing standards and specimen characteristics.

3. Specimen Clamping: Securely mount prepared specimens in the upper and lower grips of the universal testing machine. Ensure specimens are aligned without skew or additional stress, maintaining their axis parallel to the tensile direction.

4. Testing Execution: Activate the universal testing machine to apply tensile force at the preset speed. Continuously record changes in tensile force and elongation during testing.

5. Test termination and data processing: The machine automatically stops when the specimen breaks. Calculate the tensile strength of rubber or plastic using relevant formulas based on the recorded maximum tensile force and the specimen's original cross-sectional area. Simultaneously, organize and analyze the test data to derive the test results.

6. Through standardized operation adhering to the above testing principles, standards, equipment, and procedures, the tensile strength of samples can be accurately determined, providing robust technical support for quality evaluation and application of rubber and plastic products.

The operational workflow of rubber and plastic tensile strength testing specifications and high-performance testing equipment are both indispensable. UTSTESTER has dedicated over 20 years to advancing testing instrumentation, expanding from textile inspection into rubber, plastics, metals, and other industries. Leveraging accumulated expertise, our universal tensile testing machines deliver a comprehensive “testing solutions + equipment supply + after-sales support” one-stop service.

For customized testing solutions tailored to specific materials or to schedule equipment demonstrations, please contact our customer service team!