ASTM D1781-98 (R2021) pdf free download.Standard Test Method for Climbing Drum Peel for Adhesives.
1 .1 This test method covers the determination of the peel resistance of adhesive bonds between: a relatively flexible adherend and a rigid adherend: and the relatively flexible facing of a sandwich structure and its core, when tested under specified conditions.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
3. Terminology
3.1 Definitions—Many of the terms used in this test method are defined in Terminology D907.
4. Summary of Test Method
4.1 Determine the peeling force of a conditioned adhesive bonded sandwich assembly by peeling a face skin around a circular drum. This is done by clamping the assembly in a universal test machine. The average peeling load is determined using a standard formula.
5. Signihcance and Use
5.1 This test method may be used to determine comparative rather than fundamental measurements of adhesion and is particularly suitable for process control, some examples of which are listed.
5.1.1 This test method is particularly sensitive to adherend surface preparation and is of value where the adhesive is used in conjunction with a primer.
5.1.2 When a relatively brittle adhesive is used, the peel resistance can often give an indication of the degree of cure, that is, higher values than normally realized may indicate an incomplete cure. Direct comparison of different adhesives or processes can only be made when specimen design and test conditions are identical.
6. Apparatus
6.1 Peeling Apflarduus, consisting of a flanged drum, flexible loading straps or cables, and suitable clamps for holding the test specimen. The apparatus illustrated in Fig. I has been found to he satisfactory.
6.1.1 The outside radius of the drum is 51.00 ± 0.13 mm (2.000 ± 0.005 in.), and the radius of the flange, including one half of the thickness of the loading straps or cables, is 12.70 ± 0.13 mm (0.5(X) ± 0.(X)5 in.) larger than the radius of the drum. This 12.70 ± 0.13 mm (0.500 ± 0.005 in.) less half the thickness of the adherend to he peeled. is the effective torque arm of the apparatus.
6.1.2 Use a suitable top clamp (Fig. 2) for supporting the specimen. and a drum clamp (Fig. 3) to hold the adherend against the face of the drum.ASTM D1781 pdf download.