Edge Crush Test (ECT)

The edge crush test (ECT) is a standard method used to evaluate the edgewise compressive strength of corrugated fibreboard. It measures how well a sample can resist crushing when a force is applied directly to its edge. This property is critical for determining the stacking strength of packaging, where vertical loads are supported primarily by the box edges.

In the packaging industry, ECT results are an essential part of quality control. They directly relate to the structural integrity and durability of corrugated boxes during storage, handling, and transportation. Accurate ECT measurements help packaging engineers design cartons that meet performance requirements while optimising material use and cost.

ECT assesses the capacity of corrugated board to withstand compressive forces along its edge. A higher ECT value generally means the board has greater stacking strength. This information allows packaging designers to select suitable board grades for the intended application without over-specifying materials.

TAPPI and ISO standards

ECT is governed by internationally recognised standards that ensure accuracy, repeatability, and comparability of results.

• TAPPI T 811 specifies the short column method, where the specimen edges are waxed to prevent premature failure and ensure accurate measurement of true edgewise compressive strength. This method is common in North America for high precision testing.
• ISO 3037 describes the unwaxed edge method for determining edgewise crush resistance. This method is widely used in European production environments for rapid quality checks.

The choice between these methods depends on regional requirements, the level of precision needed, and whether results must align with specific regulations.

Sample preparation

• Cut specimens to standard dimensions with clean, parallel edges.
• Condition samples in a controlled temperature and humidity environment to ensure consistent moisture content.
• Wax edges if required by the chosen standard.

Test setup

• Position the specimen vertically between two compression plates.
• Apply the load perpendicular to the flute direction.

Testing procedure

• Apply a steadily increasing compressive load until the specimen fails.
• Record the maximum force sustained before failure in kilonewtons per metre (kN/m) or pounds-force per inch (lbf/in).

Mecmesin supplies precision compression testers and dedicated ECT fixtures designed for accuracy and repeatability. Systems such as the OmniTest and MultiTest-dV ranges, when paired with VectorPro software, enable precise force application, automated data capture, and compliance with both TAPPI T 811 and ISO 3037.

Fixtures can be configured to also perform flat crush and ring crush tests, providing versatility for packaging laboratories.

Factors influencing results

• Flute type and size - A-flute, B-flute, C-flute, or combinations such as double-wall can affect edgewise strength.
• Material quality - Fibre composition, paper grade, and adhesive quality influence performance.
• Moisture content - High humidity can soften paper fibres and reduce strength.
• Specimen preparation - Poorly cut edges or inconsistent samples can cause premature failure.

ECT values should be considered alongside other packaging tests such as the box compression test (BCT) to give a complete picture of performance under real-world conditions.

Design and development

ECT results guide engineers in selecting the correct board grade for the intended application, balancing performance and cost.

Quality control

Regular ECT checks ensure production consistency and compliance with customer specifications.

Example applications:

• Food and beverage: Maintaining stability in stacked retail displays.
• Pharmaceuticals: Protecting sensitive products in distribution.
• Electronics: Ensuring packaging withstands extended storage and transport.

While ECT measures the compressive strength of the board material, the box compression test (BCT) measures the strength of a complete box.

• ECT is a controlled material-level test, ideal for predicting stacking performance when combined with box size and design factors.
• BCT assesses the full packaging system, including seams, folds, and closures.

Using both tests together allows manufacturers to optimise board choice and validate box performance.

Standards-compliant precision testing

Mecmesin’s ECT solutions meet the requirements of both TAPPI T 811 and ISO 3037. High-resolution load cells, robust compression fixtures, and advanced control systems ensure accurate, repeatable, and compliant results.

Versatile testing for packaging performance

From R&D laboratories to high-volume production lines, Mecmesin offers modular ECT fixtures that can be adapted for multiple corrugated board tests. Combined with VectorPro software, operators can capture detailed data, automate calculations, and generate full test reports for quality documentation.

For advice on selecting the best ECT solution for your packaging application, contact Mecmesin’s technical team. Our specialists will recommend the right configuration to deliver standards-compliant, repeatable, and reliable results, helping you improve packaging performance and maintain quality across production.