View source for Fixed-arm Peel Test

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<span style="font-size:1.2em;font-weight:bold;">Fixed-arm peel test</span>
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==Fundamentals of the method==

The fixed-arm peel test is used to characterise the peel behaviour (see: [[Peel Process|peel process]]) of peel systems as a function of the [[Peel Angle|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|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 [[Material Testing Machine|universal testing machine]]. The clamping length is ''l''<sub>0</sub> = 25 mm and the [[Crosshead Speed|crosshead speed]] is ''v''<sub>T</sub> = 100 mm/min. The [[Peel Angle|peel angle]] is generally varied between 70° and 180°, whereby a [[Peel Angle|peel angle]] of 70° represents the lower limit for a meaningful investigation of the [[Peel Properties of Peel Systems|peel properties of peel systems]] as a function of the peel angle, since for [[Peel Angle|peel angles]] < 70°, shearing within the [[Sealed Seam|seal seam]] is to be expected as the cause of failure. To achieve a constant [[Peel Angle|peel angle]] throughout the entire [[Peel Process|peel process]], the fixed-arm peel tester can be moved sideways.

[[File:Fixed-Arm-Peel_Fig-1.jpg|450px]]
{| 
|- valign="top"
|width="50px"|'''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|peel force–fracture path diagram]] is recorded, from which the application-related [[Measured Variable|measured variable]] [[Peel Force|peel force]] can be obtained. The energy-determined [[Material Parameter|parameter]] [[Adhesive Energy Release Rate|adhesive energy release rate]] is used for the fracture mechanical characterisation of the [[Peel Process|peel process]].

Using the example of the peel system low-density polyethylene blended with isotactic polybutene-1 ([[Plastics – Symbols and Abbreviated Terms|abbreviation]]: PE-LD/iPB-1), the [[Peel Force – Fracture Path Diagram|peel force – fracture path diagrams]] (peel curves) recorded during the [[Fixed-arm Peel Test|fixed-arm peel test]] for different [[Peel Angle|peel angles]] of 90° and 130° as well as 160° and 180° are shown in '''Fig. 2'''.

[[File:Fixed-Arm-Peel_Fig-2.jpg|400px]]
{| 
|- valign="top"
|width="50px"|'''Fig. 2''': 
|width="600px" |[[Peel Force – Fracture Path Diagram|Peel force – fracture path diagrams]] for different [[Peel Angle|peel angles]]
|}

While a pronounced plateau in the [[Peel Force|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 Angle|peel angles]] show a strong deformation-dependent behaviour of the peel force. To take this pronounced deformation behaviour into account, especially at large [[Peel Angle|peel angles]], the fracture mechanical parameter [[Adhesive Energy Release Rate|adhesive energy release rate]] ''G''<sub>aIc</sub> can be used to characterise the [[Peeling Process|peel process]] at defined peel angles.

==See also==

* [[Peel Properties of Peel Systems|Peel properties of peel systems]]
* [[Peel-Cling Test|Peel-cling test]]
* [[Peel Test|Peel test]]
* [[T-Peel Test|T-Peel test]]

==Referecnces==

* Moore, D. R., [[Williams, James Gordon|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, Michael|Nase, M.]], Langer, B., [[Grellmann,_Wolfgang|Grellmann, W.]]: Bruchmechanische Kennwertermittlung im T-Peeltest und im Fixed-Arm Peeltest. In: Frenz, H., [https://www.researchgate.net/profile/Wolfgang-Grellmann 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, Katrin|Reincke, K.]], [https://de.wikipedia.org/wiki/Wolfgang_Grellmann 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) [http://www.imperial.ac.uk/media/imperial-college/research-centres-and-groups/adhesion-and-adhesives-group/ESIS-peel-protocol-(June-07)-revised-Nov-2010.pdf Download as PDF] (accessed on 21/10/2025)
* Reincke, K.: Testing of Polymeric Films. In: Grellmann, W., [[Seidler, Sabine|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)

[[Category:Film Testing]]
[[Category:Peel Test]]