Climbing Drum Peel

Climbing drum peel testing is a specialised method used to measure the adhesive strength between bonded materials, particularly in flexible-to-rigid substrate combinations such as aluminium skins bonded to honeycomb cores. The test replicates real-world peeling forces to determine whether adhesive bonds will maintain integrity under operational stresses.

The method records the peel force required to separate two adhered surfaces in a controlled, repeatable manner. This is typically expressed as the average peel strength over a given length, calculated from the measured force. In sectors such as aerospace, automotive, and high-performance composites, climbing drum peel testing is essential because adhesive failure can lead to structural weakness or complete product failure.

In some applications, additional parameters such as the chord modulus are derived. This measures the stiffness of the adhesive joint and, when combined with peel strength data, provides a more complete understanding of adhesive performance.

In a climbing drum peel test, one end of a bonded specimen is clamped to a rotating drum while the other end is fixed to the crosshead of the test machine. As the crosshead moves vertically, the drum rotates and steadily peels the flexible layer away from the rigid substrate. This produces a constant peeling angle and a controlled rate, allowing accurate force measurement.

The climbing action ensures peeling is consistent along the sample length. This is important for simulating operational scenarios where adhesives experience gradual peeling stresses rather than sudden force application. The method is particularly useful for quality assurance of bonded panels, laminates, and layered composites.

Commonly used standards include:

• ASTM D1781 - method for determining peel resistance of adhesives used in bonding rigid-to-flexible materials, such as sandwich constructions and honeycomb panels.
• ASTM D1995 - procedures for peel testing of pressure-sensitive adhesives.
• ISO 11339 - climbing drum peel test method for adhesives used in structural bonding applications.

Following these standards ensures test results are consistent, comparable, and compliant with industry and regulatory requirements.

The main stages are:

• Sample preparation - Cut specimens to precise dimensions specified in the chosen standard.
• Initial setup - Mount the bonded specimen to the climbing drum fixture, ensuring alignment to prevent uneven peeling forces.
• Testing - Apply a controlled peel rate using the test machine, recording the force throughout.
• Data capture - Use software to calculate average peel strength over the specified length.

• Misalignment can cause uneven peeling forces. Solution: use precision fixtures and ensure correct specimen mounting.
• Inconsistent peel rates from manual operation can lead to variability. Solution: use a motorised test stand for constant crosshead speed.
• Material deformation may affect readings. Solution: adjust peel rate or use a backing fixture to minimise flexing.

• Aerospace - testing honeycomb panels for aircraft interiors and structural assemblies.
• Automotive - evaluating bonded panels, trim, and composite assemblies.
• Packaging - assessing peel strength of bonded laminates and foil seals.
• Electronics - checking adhesion in layered materials such as flexible printed circuits.

Modern systems incorporate high-resolution digital sensors for precise force measurement, real-time data capture with analytical software, and automation to reduce operator influence. These improvements increase repeatability and speed up product development cycles.

Precision peel testing systems

Mecmesin offers test platforms such as the OmniTest and MultiTest-dV, fitted with adaptable climbing drum fixtures, to meet ASTM D1781, ASTM D1995, and ISO 11339 requirements. Systems can test a wide range of material combinations, from thin films to rigid panels, with measurement accuracy to ±0.1% of reading.

Software aligned with standards

VectorPro software provides automated calculations, including average peel strength and chord modulus, and generates fully traceable compliance reports.

Versatile and configurable solutions

From R&D to high-volume production, Mecmesin’s modular systems can be adapted with custom fixtures to accommodate different adhesive types, substrates, and geometries.

Global service and support

Mecmesin offers worldwide calibration, training, and technical assistance. Support covers equipment validation, operator training, and process optimisation to maintain compliance and testing accuracy.

The climbing drum peel test is a critical method for evaluating adhesive bond strength where performance and safety cannot be compromised. For guidance on selecting the right climbing drum peel testing equipment, advice on compliance, or to arrange a demonstration tailored to your application, contact a Mecmesin specialist.