Removal Torque

Removal torque testing measures the rotational force required to unscrew or disengage a closure from its container. In packaging, it is used to verify that closures are not too loose, which can lead to leaks or contamination, and not too tight, which can make opening difficult for the consumer.

By confirming that closures are applied within an optimal torque range, manufacturers ensure that products meet quality expectations, user safety requirements, and relevant industry standards.

Removal torque is critical to packaging performance and user experience. In child-resistant closures, it helps confirm compliance with safety regulations while maintaining usability for adults.

An optimal removal torque ensures:

• Consumer safety by reducing unintended access to hazardous or pharmaceutical products
• Leak prevention during handling, transport, and storage
• Brand consistency by providing a uniform opening experience across all units

Removal torque testing applies to a wide range of packaging formats including plastic and glass bottles, jars, metal-lidded containers, and flexible pouches with threaded spouts.

Manual torque testing

Manual torque testing uses handheld or bench-mounted torque testers. The operator applies rotational force to remove the closure, and the instrument records the peak torque value.

Advantages:

• Lower initial investment cost
• Flexible testing for varied closure designs
• Suitable for small-scale or batch testing

Limitations:

• Greater potential for operator variability
• Less efficient for high-volume testing environments

Automated torque testing

Automated torque testers use motor-driven systems to remove closures with controlled speed, alignment, and top-load pressure.

Advantages:

• High repeatability by eliminating operator influence
• Accurate digital data capture and reporting
• Faster throughput for production environments
• Easy integration into in-line quality control processes

Applications include pharmaceutical bottling lines, beverage production, and food packaging plants where compliance and consistency are essential.

Key standards

• ASTM D2063 - Specifies torque retention testing for thread closures, covering sample conditioning, test procedure, and equipment accuracy
• ASTM D3469 - Defines disengagement torque for child-resistant lug closures, supporting regulatory safety compliance
• ISO 16047 - Provides torque test methodology, with procedural adaptations for packaging applications depending on closure type and material

These standards specify requirements for sample preparation, environmental conditioning, torque tester calibration, and test speed to ensure consistency across laboratories and production sites.

Importance for regulated industries

In pharmaceuticals, agrochemicals, and hazardous materials packaging, removal torque testing is a compliance requirement. By adhering to ASTM and ISO standards, manufacturers can:

• Avoid costly recalls or non-compliance penalties
• Demonstrate product safety to regulators
• Maintain consumer confidence in product quality

Sample preparation

• Condition closures and containers to the specified temperature and humidity
• Inspect samples for defects before testing
• Standardise top-load application to replicate typical user opening force

Equipment selection and calibration

• Choose torque testers, grips, and fixtures appropriate to closure size and material
• Ensure fixtures prevent slippage without damaging the closure
• Calibrate torque meters at recommended intervals, with high-use equipment checked more frequently

Example: For a 28 mm PET bottle cap, typical removal torque in beverage applications may range between 0.8 and 1.2 N·m, depending on carbonation levels and liner design.

Mecmesin offers manual and automated torque testing solutions designed for packaging manufacturers, quality control teams, and compliance officers. Our equipment supports a wide range of closure sizes and test requirements, providing precise, repeatable measurements in accordance with ASTM and ISO standards.

Technical advantages include:

• Systems including the Vortex, Vortex-xt, OmniTest, and MultiTest-dV for different test capacities
• High-precision load cells for accurate torque measurement
• VectorPro software for data capture, analysis, and reporting
• Customisable fixtures and grips for closures of all shapes, sizes, and materials
• Options for both laboratory testing and high-throughput production environments

Mecmesin torque testers are trusted in industries including pharmaceuticals, food and beverage, household chemicals, and cosmetics, where closure performance and compliance are critical.

To discuss your removal torque testing requirements and identify the most suitable Mecmesin system for your application, speak to one of our technical experts today.