Standard Test Method for Climbing Drum Peel for Adhesives - ASTM D1781

Peel resistance of adhesive bonds using ASTM D1781

This test method is used to compare adhesion between flexible and rigid adherends, or between flexible facing of a sandwich structure and its core. Comparisons of adhesives and processes are only applicable when test specimens and conditions are the same. The peel resistance may indicate degree of cure for relatively brittle adhesives.

Test procedure:

Specimens are placed in the climbing drum peel apparatus. The grips of a Universal Test Machine are initiated at a specified grip separation significant enough to roll the drum upward. The standard speed is 25.40 ± 2.54 mm/min [1.00 ± 0.10 in/min].

Specimen size:

Six specimens tested. Samples need to be thick enough not to bend during test.

• For laminates, 25 mm [1 in] wide between saw kerfs by at least 254 mm [10 in].
• For adhesives in sandwich construction, 76 mm [3 in] wide between saw kerfs by at least 305 mm [12 in], including ~25 mm [1 in] overhang of one facing at each end.
• For adhesives in bonding metal-faced sandwich construction, a facing of clad aluminum alloy meeting Specification B29, Alloy 2024-T3, 0.51 mm [0.020 in] thick with a core 12.7 mm [0.5 in] thick, or comparably flexible material is required.

Data:

From climbing drum peel results the following calculations can be made:

1. Average peeling load
2. Maximum peeling load
3. Minimum peeling load
4. Average peel torque
5. Failure type/mode

**Please note that this test description is intentionally generic in nature and aimed at providing a descriptive summary to enhance test understanding. Standards can be obtained from appropriate standard authorities.