Tension

Tension methods are a core approach in texture analysis, used to measure how a material behaves when subjected to a pulling force until it deforms or fails. In both the food and packaging industries, these tests quantify performance characteristics such as elasticity, tensile strength, and elongation at break.

In food applications, tension testing assesses qualities such as chewiness, stretchiness, or bite firmness. In packaging, it determines the durability of films, seals, and other materials that must withstand handling, transport, and storage. By providing objective, repeatable data, tension methods support consistent quality assurance and informed product development.

Tension testing follows a defined process to ensure accuracy and repeatability:

• Specimen preparation – Food samples, such as noodles, confectionery strips, or baked goods, and packaging materials, such as film strips, bottle caps, or heat seals, are cut to a standard size and shape, in line with relevant standards such as ASTM D882 for thin plastic films or ISO 527 for plastics.
• Mounting in fixtures – The sample is secured in appropriate grips or fixtures designed to hold it firmly without slippage or premature damage. Mecmesin offers a variety of grip types, including pneumatic and mechanical, to suit different materials and sample dimensions.
• Setting test parameters – Using VectorPro software, the operator sets the test speed, pre-load force, and target displacement or break point. Parameters are tailored to the product and standard being tested.
• Applying the load – The crosshead moves at the set speed, pulling the specimen until it stretches, deforms, or breaks.
• Data capture – Load and displacement data are recorded throughout the test to generate a force–distance or force–time graph.
• Analysis – Results are reviewed for metrics such as peak force (ultimate strength), modulus of elasticity, and percentage elongation. A change in test speed from 50 mm/min to 100 mm/min, for example, can alter measured tensile strength in thin films by over 15 percent, highlighting the importance of consistent methodology.

Elasticity determines how well a material returns to its original shape after stretching. Ultimate strength indicates the maximum stress it can withstand before failure.

In food products, these properties influence sensory qualities such as mouthfeel, snap, or stretch, for example, the elasticity of pasta strands or the tensile strength of a caramel strip. In packaging, they affect durability under stress, such as the tear resistance of cling film or the seal integrity of sachets.

Testing both attributes ensures products meet performance expectations during use, transport, and storage. This reduces the risk of breakage, spoilage, or consumer dissatisfaction, and supports compliance with industry standards.

Tension methods replicate real-world conditions experienced by food products during production, handling, and consumption. By simulating stretching, pulling, or tearing forces, manufacturers can design foods with consistent texture and optimise production settings.

Examples include:

• Measuring the tensile strength of dried noodles to ensure they do not break prematurely during cooking.
• Testing the elasticity of cheese or dough to maintain the desired stretch in pizzas and baked goods.
• Evaluating the firmness of confectionery strips to ensure uniform bite and mouthfeel.

Regular testing supports batch consistency and enables early detection of changes in ingredient quality or processing parameters.

Tension testing plays an essential role in packaging development, enabling material selection and refinement for durability and performance. Typical assessments include:

• Tear resistance – Ensuring films and wraps resist accidental tearing but can still be opened when intended.
• Seal strength – Confirming that heat seals in pouches or blister packs maintain integrity during transport yet peel cleanly when opened.
• Elongation at break – Optimising stretch films to balance flexibility with puncture resistance.

These tests simulate handling, distribution, and storage conditions, reducing the risk of damage and wastage.

Mecmesin has decades of experience in precision tension testing for the food and packaging industries. Our OmniTest and MultiTest-dV systems are designed to replicate real-world conditions and deliver highly repeatable data for both R&D and quality control.

Key strengths include:

• Customisable test systems – Loadcell capacities from a few newtons to several kilonewtons, with resolution accuracy better than 0.1 percent of full scale.
• Advanced software control – VectorPro provides intuitive test setup, real-time monitoring, automated calculations, and secure data export.
• Versatile gripping solutions – A wide range of grips and fixtures to accommodate delicate food products through to high-strength packaging films.
• Compliance and traceability – Systems can be configured to meet ASTM, ISO, and BS standards, with calibration certificates for audit readiness.

From determining the elasticity of bakery products to measuring the seal strength of sachets, Mecmesin equipment enables engineers to make confident, data-driven decisions about product quality and performance.

Discuss your requirements with a Mecmesin specialist to identify the right tension testing solution for your product and process.