What Is Peel Test?
The peel test is a test in which the force required to separate two bonded surfaces at a defined angle is measured. The result is given as force per unit width.
Purpose of Peel Test
The purpose is to determine the strength and consistency of the adhesive or laminate bond, providing quality control for tape, label, film and coating applications.
Which Products Is Peel Test Applied To?
- Adhesive tape and labels
- Laminated films and packaging
- Coated sheet and membrane
- Textile laminates
- Adhesive bonds
In Which Sectors Is Peel Test Used?
Standards Related to Peel Test
- ISO 8510-1
- ISO 8510-2
- ISO 11339
- ASTM D903
- ASTM D1876
Peel Test Conditions
- Peel angle
- 90° or 180°; two flexible parts in a T-peel arrangement
- Peel rate
- Constant rate per the standard; typically 100 or 300 mm/min
- Environment
- 23 °C ± 2 °C and 50% ± 5 relative humidity
- Specimen width
- Defined in the standard (commonly 25 mm)
Equipment for Peel Test
- Universal testing machine
- 90-degree peel fixture
- T-peel grips
- Conditioning chamber
Sample Requirements for Peel Test
- Specimen width must be cut per the standard
- An initial separation is prepared before the test
- The dwell time after bonding must be recorded
- Generally at least five specimens per set
Duration of Peel Test
Testing per specimen takes a few minutes; a set including conditioning takes half a working day.
Peel Test Procedure
- 1Specimens are prepared to the width defined in the standard.
- 2Conditioning is completed and the initial separation is made.
- 3The specimen is placed in the peel fixture.
- 4Peeling is applied at the defined rate; force is recorded continuously.
- 5The average peel force in the steady-state region is calculated.
Peel Test Acceptance Criteria
The acceptance criterion is given in the specification as a minimum peel force per unit width (e.g. N/25 mm).
Evaluation of Results
The steady-state region of the force curve is used as the basis; the initial peak is excluded from evaluation. The mode of failure (adhesive or cohesive) is recorded separately.
Peel Test Report
- Applied standard and peel arrangement
- Peel rate and angle
- Specimen width and conditioning
- Average peel force
- Mode of failure and force curve
Accreditation
EUROLAB holds internationally recognised accreditation obtained from accreditation bodies party to the IAF and ILAC multilateral recognition arrangements, under ISO/IEC 17025 for laboratory testing, ISO/IEC 17020 for inspection and surveillance, and ISO/IEC 17021-1 and ISO/IEC 17065 for system and product certification. This chain ensures the reports and certificates issued are accepted worldwide.
Whether this test can be offered within accredited scope depends on your product and the standard applied; since accreditation is method-based, the scope is confirmed in writing at the quotation stage.
Scope and authorisationsRelated Regulations
- Packaging and adhesive product specifications
Mekanik Testler — What Does This Testing Field Cover?
The section below describes the field that the Peel Test test belongs to; the conditions and acceptance criteria of this particular test are given in the sections above. The scope specific to your product is confirmed in writing at the quotation stage.
Mechanical testing measures how a material or a part behaves under force. The family ranges from static loading (tension, compression, bending) to time-dependent behaviour (fatigue, creep), and from hardness and wear to fracture toughness.
What these tests have in common is that the result is reported as a MATERIAL PROPERTY. Yield strength or hardness is not a conformity decision; it is numerical data against which the design and the product standard will compare. Mechanical test reports are therefore usually an input to an engineering decision rather than to a product approval — material selection, safety factor, life prediction.
The distinction between static and dynamic behaviour is the key to understanding the field. A part may appear entirely unstressed under a static load yet break under repeated loading; fatigue fracture occurs at stresses well below the yield strength and gives no warning. For rotating, vibrating or cyclically loaded parts, a tensile test alone is therefore not sufficient evidence.
Test conditions determine the result, and this is critical for the readability of the report: specimen geometry, loading rate, temperature, conditioning and the gripping arrangement. The same material gives different values under different conditions. In plastics the rate effect is very pronounced, in metals the temperature effect; in composites the specimen orientation changes the result entirely.
Hardness is the most misused measurement in the field. Because it is fast, close to non-destructive and inexpensive, it is often used in place of strength. Conversion tables from hardness to strength exist, but they are APPROXIMATE and depend on the material group; using them as the sole evidence in material acceptance is wrong.
The fracture mechanics side requires a specific competence. Fracture toughness and fatigue crack growth rate measurements make it possible to calculate how long a cracked structure will last; they are the basis of damage-tolerant design in fields such as pressure equipment, aircraft structures and pipelines.
Method groups in this field
Static tests
Tension, compression, bending, shear and torsion. Yield and tensile strength, elongation and modulus of elasticity are obtained.
Impact tests
Charpy and Izod notch impact; the brittle-to-ductile transition behaviour of the material is determined as a function of temperature.
Hardness
Brinell, Vickers, Rockwell, Shore and micro hardness. Valuable for surface treatment depth and local differences in strength.
Fatigue
Force- and strain-controlled axial fatigue, fatigue in bending; S-N curves and the endurance limit.
Creep and stress relaxation
Behaviour under long-term load at high temperature; decisive for boiler, turbine and pressure equipment materials.
Fracture mechanics
Plane-strain fracture toughness, the J integral, CTOD and fatigue crack growth rate.
Wear and friction
Taber and rotating drum abrasion, coefficient of friction measurements.
Commonly confused in this field
- Calculating strength from hardness is approximate; it cannot be used as the sole evidence in material acceptance.
- Adequate static strength does not demonstrate fatigue strength; a cyclically loaded part requires a separate test.
- If test rate and temperature are not reported, the result cannot be compared — especially for polymers and composites.
- A test specimen and the actual part may not give the same value; moulding orientation, weld lines and differences in surface treatment all have an effect.
- A strength value given for a composite without stating the specimen orientation is meaningless.
- ASTM and ISO counterparts measure the same quantity but use different specimen geometries; the results are not treated as directly equivalent.
Which decisions these results support
- Design verification and material selection
- Incoming material control and supplier approval
- Meeting the mechanical requirements of the product standard
- Failure analysis, life prediction and damage tolerance calculation
- Verifying heat treatment and surface treatment processes
Related Tests
Frequently Asked Questions About Peel Test
Are 90° and 180° peel results comparable?
Not directly. Peel angle significantly affects the measured force; the result is therefore always reported together with the angle.