Fixed-arm Peel Test
Fixed-Arm-Peeltest | A service provided by |
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Fixed-arm peel test
Fundamentals of the method
The fixed-arm peel test is used to characterise the peel behaviour (see: peel process) of peel systems as a function of the peel angle (Fig. 1) and is performed in accordance with the ESIS TC4 standard proposal “Peel Testing of Flexible Laminates.” The term “fixed arm” means that one of the two peel arms has a fixed peel angle of 0°, while the peel angle of the second peel arm is variably adjustable. One peel arm of the test specimen is glued to a narrow brass plate, whereby the adhesive force must be many times greater than the expected peel force. Once the test specimen has been prepared, the brass plate is mounted in the fixed-arm peel tester and the remaining free peel arm is clamped in the clamping device of a universal testing machine. The clamping length is l0 = 25 mm and the crosshead speed is vT = 100 mm/min. The peel angle is generally varied between 70° and 180°, whereby a peel angle of 70° represents the lower limit for a meaningful investigation of the peel properties of peel systems as a function of the peel angle, since for peel angles < 70°, shearing within the seal seam is to be expected as the cause of failure. To achieve a constant peel angle throughout the entire peel process, the fixed-arm peel tester can be moved sideways.
| Fig. 1: | width="600px" Schematic representation of the fixed-arm peel test |
Influence of the peel angle
During the peel test, a peel force–fracture path diagram is recorded, from which the application-related measured variable peel force can be obtained. The energy-determined parameter adhesive energy release rate is used for the fracture mechanical characterisation of the peel process.
Using the example of the peel system low-density polyethylene blended with isotactic polybutene-1 (abbreviation: PE-LD/iPB-1), the peel force – fracture path diagrams (peel curves) recorded during the fixed-arm peel test for different peel angles of 90° and 130° as well as 160° and 180° are shown in Fig. 2.
| Fig. 2: | Peel force – fracture path diagrams for different peel angles |
While a pronounced plateau in the peel force can be seen for peel angles of 90° and 130° from a fracture path of approx. 2 mm, no such plateau is found for 160° and 180° as a basis for a uniform peel process. Compared to those at 90° and 130°, the peel curves at 160° and 180° peel angles show a strong deformation-dependent behaviour of the peel force. To take this pronounced deformation behaviour into account, especially at large peel angles, the fracture mechanical parameter adhesive energy release rate GaIc can be used to characterise the peel process at defined peel angles.
See also
Referecnces
- Moore, D. R., Williams, J. G.: Peel Testing of Flexible Laminates. In: Moore, D. R., Pavan, A., Williams, J. G. (Eds.): ESIS TC4 Publication 28 – Fracture Mechanics Testing Methods for Polymers Adhesives and Composites, pp. 203–223, Elsevier, Amsterdam (2001) (ISBN 0-08-043689-7; see AMK-Library under E 3)
- Nase, M., Langer, B., Grellmann, W.: Bruchmechanische Kennwertermittlung im T-Peeltest und im Fixed-Arm Peeltest. In: Frenz, H., Grellmann, W. (Eds.) 26. Tagung Werkstoffprüfung „Herausforderung neuer Werkstoffe an die Forschung und Werkstoffprüfung“, Berlin (2008) Proceedings pp. 223–228, (ISBN 978-3-00-026399-6; see AMK-Library under A 10)
- Nase, M.: Zusammenhang zwischen Herstellungsbedingungen, übermolekularer Struktur und Eigenschaften von Peelfolien. Shaker Publishing 2010 (ISBN 978-3-8322-9099-3; see AMK-Library under B 1-17)
- Reincke, K., Grellmann, W.: Verfahren zur Charakterisierung der mechanischen Eigenschaften von Folien und Elastomeren. In: Grellmann, W. (Ed.): Neue Entwicklungen in der Werkstoffprüfung – Herausforderungen an die Kennwertermittlung. Tagung "Werkstoffprüfung 2011", 1 and 2 December 2011, Berlin, Proceedings pp. 185–192 (ISBN 978-3-9814516-1-0; see AMK-Library under A 13)
- ESIS-TC4: A Protocol for Determination of the Adhesive Fracture Toughness of Flexible Laminates by Peel Testing: Fixed-Arm and T-Peel Methods (2010) Download as PDF (accessed on 21/10/2025)
- Reincke, K.: Testing of Polymeric Films. In: Grellmann, W., Seidler, S. (Eds.): Polymer Testing. Carl Hanser Verlag München (2022). 3rd. Edition, pp. 643–678 (ISBN 978-1-56990-806-8; e-Book ISBN 978-1-56990-807-5; ePub ISBN 978-1-56990-808-2; see AMK-Library under A 22)