Elastic limit

The yield strength represents the maximum stress a material can withstand before exhibiting permanent deformation. It is an essential mechanical parameter for evaluating the strength, rigidity, and durability of a product or component.

This value is determined during a tensile or compression test , according to ISO 527 for polymer materials. The analysis makes it possible to identify the transition between the elastic (reversible) and plastic (irreversible) phases, ensuring control of mechanical properties during dimensioning, quality control, or formulation .

Principle of measurement

During the test, a sample is subjected to increasing stress until the deformation is no longer proportional to the applied load.
The yield strength (Re) is then defined as the stress at which the material ceases to behave elastically .

The test is performed using a dynamometer or tensile testing machine , equipped with a force sensor and an extensometer. The parameters measured include:

• the elastic stress (Re) ,
• Young's modulus (E ) ,
• deformation at rupture ,
• and sometimes tenacity (energy needed to break through).

This data is essential for evaluating the performance of materials used in packaging, polymers, technical components or finished products .

For further analysis, see also:

• the tensile test to measure resistance and elongation at break,
• the bending test to determine the stiffness under deformation,
• and the compression test to evaluate resistance under load.

Industrial applications

The measurement of the elastic limit applies to a wide variety of materials and sectors:

• Materials and polymers : control of the mechanical resistance of plastics, composites and elastomers for molding or extrusion.
• Packaging : checking the strength of films, trays, caps or containers subjected to mechanical stress.
• Cosmetics and pharmaceuticals : study of the resistance of primary and secondary packaging (bottles, tubes, lids).
• Agri-food and nutraceuticals : validation of packaging intended for food contact or liquid and solid supplements.
• Plant and bio-based materials : characterization of the mechanical strength of biopolymers and ecological alternatives.

This analysis guarantees that the materials conform to industrial standards , while ensuring their performance under real-world conditions.

Analytical interest and complementarity

The study of the elastic limit is often coupled with other mechanical or thermal analyses to fully characterize the behavior of the material:

• Melt flow index (MFI) to link polymer viscosity to its mechanical properties,
• Thermal DSC analysis to observe melting and crystallization transitions
• TGA analysis to assess thermal stability
• FTIR infrared spectroscopy to verify chemical composition,
• Accelerated aging test to observe the evolution of mechanical properties over time.

These combined approaches offer a complete characterization of the material , from its molecular structure to its final mechanical performance.

YesWeLab Services

YesWeLab provides access to a network of partner laboratories accredited to ISO 17025 and/or COFRAC , specializing in mechanical and rheological testing .
Our experts define the experimental protocol best suited to your matrix (plastic, metal, composite, biopolymer) and interpret the results according to regulatory and industrial requirements.

Thanks to the YesWeLab digital platform , you can centralize your analysis requests, track your samples, and access your results reports online.
Since 2020, YesWeLab has been supporting players in the packaging, polymer, and technical materials sectors with their strength and mechanical performance studies.

To obtain a quote or a customized analysis solution, contact our scientific team now.