180 Degree Peel

The 180 degree peel test is a recognised method for measuring the strength of adhesive bonds when a material is peeled back on itself at a constant angle of 180 degrees. It is commonly applied to pressure-sensitive tapes, films, laminates and flexible packaging.

In this test the adhesive bond between two materials is progressively separated while the peeled material is folded flat against itself. The machine records the average peel force over a set distance, providing engineers with a reliable measure of adhesion strength and behaviour.

Compared with other peel geometries such as the 90 degree peel or T-peel, the 180 degree peel test is straightforward to set up and particularly suitable for tapes and laminated structures.

Peel adhesion is critical to the performance and safety of many products. Measuring peel strength ensures that adhesives perform consistently in real-world applications.

In packaging, blister pack seals and peel-off lids must hold securely yet open cleanly when required. In healthcare, wound dressings and medical tapes need to adhere firmly to skin but also allow safe removal without trauma. Automotive and electronic components rely on laminates and adhesive joints that withstand vibration and thermal cycling. In renewable energy and construction, laminates and protective films must deliver consistent peel performance to maintain durability and integrity over time.

By performing 180 degree peel testing, manufacturers and engineers can validate product design, demonstrate compliance with standards and support quality assurance programmes.

The test is carried out on a universal testing machine fitted with a suitable peel fixture.

Specimens are typically pressure-sensitive tapes, flexible laminates or adhesive bonds to rigid materials such as steel, glass or plastics. The bonded section and test width are defined by the relevant standard.

One end of the specimen is gripped by the moving crosshead while the substrate is secured on a flat plate or dedicated peel jig. The adhesive is peeled back at 180 degrees as the crosshead moves at a constant speed. The choice of test speed depends on the standard in use, for example FINAT FTM1 specifies 300 mm per minute while others vary.

Force is recorded continuously during the test. Results are usually reported as the average peel strength expressed in Newtons per unit width, such as N per 25 mm. The resulting graph also reveals adhesive behaviour such as stick-slip effects or cohesive failure, which may be significant for product development.

Mecmesin provides a complete range of test solutions designed for accurate and repeatable peel strength measurement.

The OmniTest and MultiTest-dV systems offer motorised control of crosshead speed combined with precision load cells to cover a wide range of adhesive strengths. Dedicated peel jigs, such as the FINAT 1 and FPT-H1 180 degree fixtures, ensure the correct test geometry is maintained throughout the procedure.

VectorPro software captures force-displacement data, calculates average peel strength and enables detailed analysis with clear reporting. Together these systems provide engineers with confidence that results are reproducible and fully compliant with international standards.

A number of standards define the correct method for performing a 180 degree peel test. Each specifies specimen size, substrate, test speed and reporting method to ensure valid and comparable results.

• ASTM D3330 covers peel adhesion of pressure-sensitive tapes
• ASTM D903 specifies peel or stripping strength of adhesive bonds
• ISO 8510-2 defines the 180 degree peel test for flexible-to-rigid assemblies
• FINAT FTM1 sets out a procedure for 180 degree peel of self-adhesive tapes at 300 mm per minute
• PSTC 101 specifies adhesion of pressure-sensitive tapes at 180 degrees
• Afera 5001 details peel adhesion measurement from standard substrates

Selecting the correct standard depends on the adhesive material and the industry application. Mecmesin equipment and fixtures are designed to meet the requirements of these procedures, ensuring reliable and comparable test results.

Choosing the right configuration for a peel test is essential to obtain meaningful data. Test speed, specimen type, fixture design and data analysis all influence the results. Mecmesin’s technical specialists work with engineers and product developers to configure equipment for specific materials and industry needs.

For expert advice on 180 degree peel testing and to identify the most suitable equipment for your application, speak to an expert at Mecmesin.