Peel test method

Tanknoto, Y Saeki, H. Kimoto, S. Nishiwaki, T. Nishiyama,N. Evaluation of adhesive properties of three resilient denture liners by the modified peel test method. Acta. Biomater., 2009, 5(2), 764-769. 

Figure 27 Measurement of adhesion by the peel test method using thin film specimens coated on silicon wafers and cured at 350-400°C. (A) A 1 cm wide strip is cut in the polyimide film. (B) The wafer (a) is cut and broken perpendicularly to the film (b). (C) One end of the specimen is fixed with a clip (d) into the upper jig (c) of an Instron testing machine. The other part lies on a mobile carrier (e) designed to maintain a 90° peeling by means of pulleys (f) and counterweight (g).

The usual practical situation is that in which two solids are bonded by means of some kind of glue or cement. A relatively complex joint is illustrated in Fig. XII-14. The strength of a joint may be measured in various ways. A common standard method is the peel test in which the normal force to separate the joint... 

Fig. 1, Schematic of commonly u.sed methods for testing the strength of adhesive joints, (a) Peel test. Note that the peel angle can be changed depending on the test requirements, (b) Double overlap shear test. In this test, the failure is predominantly mode II. (c) Single overlap shear test. In this test the failure mode is mixture of mode I and mode II. (d) Blister test.

Fig. 17. Adhesion energy G measured as a function of the surface density of the interfacial chains. It may noted that the strength measured in a peel test (a) is about 5 times larger than that measured using the JKR method (b). Further, a maximum exists in the value of G as function of the surface chain density. This is because of swelling effects at larger values of surface chain density. The open symbols represent the data for elastomer molecular weight Mo = 24,000 and the closed symbols represent the data for Mo = 10,000.

Both static and dynamic tests are employed to evaluate the adhesion strength of cord-mbber composites. The major static tests used in tire industry are H-adhesion, 90/180° peel test, tire cord adhesion test (TCAT) and co-axial shear pull-out test (CSPT). Although these methods are... 

STM B533-85, Standard Test Methods for Peel Strength of Metal Electroplated Plastics, American Society for Testing and Materials, Philadelphia, 1998. 

Test methods have been standardised internationally for peel, direct tension, shear and tension with conical ends. 

Borroff and Wake48, and later Meardon49, developed a direct tension method which was claimed to more nearly measure the true adhesion between fabric and rubber. It is particularly useful for discriminating between adhesive systems, when the peel tests can be misleading. The main objection to the method is practical in that the preparation of test pieces is rather difficult. 

ASTM D4393, 2004. Standard test method for strap peel adhesion of reinforcing cords or fabrics to rubber compounds. 

Several TLC methods have been widely used to quantitatively estimate the flavonoids for quality control purposes rather than to detect adulteration. The potential exists, however, for testing authenticity. Naringin is an important compound in grapefruit juice, since it is largely responsible for the bitter character of the juice. Fisher et al. (121) developed a TLC procedure for naringin estimation. This was later modified by Tatum and Berry (122). Swift (123) developed a TLC-spectrophotometric assay for the neutral methoxylated flavones in orange peel. The method was subsequently expanded to the determination of these compounds in orange juice (124). 

The Standard Test Method for Strength Properties of Tissue Adhesive in T-Peel by Tension Loading, ASTM F 2256-03, was not employed for testing barrier dressings only porcine tissue was available in 15 cm strips that possessed thick hair on the epidermis side and a thick fat layer on the underside that was not conducive to testing. Removal of the fat layer to isolate the dermis will be necessary before testing by the T-Peel method. 

ASTM F 2256 - 03, Standard Test Method for Strength Properties of Tissue Adhesives in T-Peel by Tension Loading, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959. 

Peel tests, or the "one plate" method, are commonly used. These are specified in the following standards ... 

The chemical cleaning methods used for aluminum will have slightly different effectiveness with different aluminum alloys. The permanence of these bonds will also depend on the type of alloys used because of their different corrosion rates under extreme environmental conditions. The yield strength of the alloy also has an influence on bond strength when stressed in shear. The peel test is usually considered a more meaningful... 

The t-peel test is described in ASTM D 1876 and is the most popular of all peel tests. The t-peel specimen is shown in Fig. 20.7. Generally, this test method is used when both adherends are flexible. Because the angle of peel is controlled by the properties of the adherends and the adhesive, the test is less reproducible than other peel tests. A sample population of at least 10 is required, whereas most other ASTM tests require a minimum of 5. 

A variation of the t-peel test is a 180° stripping test, described in ASTM D 903. This method is commonly used when one adherend is flexible enough to permit 180° turn near the point of loading. This test offers more reproducible results than the t-peel test because the angle of peel is kept constant, although it is dependent on the nature of the adherend. 

The cleavage test utilizes a specimen where the load is intentionally placed on one edge of the bonded area. The test method is described in ASTM D 1062. The specimen is usually loaded at a rate of 0.05 in/min until failure occurs. The failing load is reported as breaking load per unit area in pounds per square inch. A standard test specimen is illustrated in Fig. 20.9. Because cleavage test specimens involve considerable machining, peel tests are usually preferred where possible. 

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