Standards for Adhesives

Many standards have been developed over the years for the testing and quality control of adhesives. These range from international standards to military specifications, aerospace, and individual company material and performance standards (such as those used by automotive manufacturers). 

For many years, industry has made use of military or defence standards. These were developed by government departments in conjunction with industrial suppliers in many countries to specify performance and quality requirements for defence procurement. They have often provided a reliable and readily available standard for other industrial users. They have also been subject to international harmonisation, primarily through the North Atlantic Treaty Organization. For example, many anaerobic threadlockers were originally developed to meet US military specifications and these are still the most widely used specifications. There is now a trend for defence organisations to use industrial standards. 

Standardisation of adhesives is done on an international, regional and national basis. There is considerable activity in trying to harmonise standards on an international basis. The most important industrial standards are those of the International Organization for Standardization (ISO), Europe, and the American Society for Testing and Materials (ASTM). 

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Pressure-sensitive adhesives are used in a great variety of applications, most commonly for adhesive tapes. In that case, they have to be tested by static shear test or dynamic shear test The difference between these two methods is that in static shear test a standard force is being applied to the test specimen and the adhesive failure is reported as the time it takes for failure to occur. The dynamic shear test involves a force being applied to the PSA tape at a specific rate of speed (typically 0.25 mm or 0.1 in. per minute). The value reported is as the peak force per unit area (Ib/in, also abbreviated as psi, and in SI units MPa) required to cause adhesive failure. The standards for adhesion shear tests are ASTM D3654, ISO EN 1943, and PSTC-107.i i ... 

There was previously a separate ISO standard for adhesion in shear but this was withdrawn in favour of extending the standard for shear modulus to allow the test to be continued to the failure point, i.e. the two methods have been combined. The composite method is contained in ISO 182715 and uses the same quadruple element test piece as did the separate adhesion standard. The double sandwich construction is intended to provide a very stiff test piece which will remain in alignment under high stresses. The present standard quadruple test piece uses rubber elements 4 1 mm thick and 20 5 mm long and these tolerances are much less tight than previously. The measured adhesion strength in shear is less affected by the test piece shape factor then tension tests8 and the wider tolerances should be perfectly satisfactory. The test piece is strained at a rate of 50 mm/min, in line with the speed for most other adhesion to metal tests, and the result expressed as the maximum force divided by the total bonded area of one of the double sandwiches. The British equivalent BS 903 Part A 1416 is identical. 

TABLE 19.4 Sources of Common Specifications and Standards for Adhesives and Sealants... 

Overview of European Standards for Adhesives Used in Wood-Based Products... 

Licari, J. J., Weigand, B. L., and Soykin, C. A., Development of a Qualification Standard for Adhesives Used in Hybrid Microcircuits, NASA Final Report CR-161978 (Dec. 1981)... 

There are a number of Standards for adhesives and adhesion that relate to environmental exposnre and test conditions. These exist within industry sectors and are also, in some instances, the subject of both nationally and internationally agreed standards docnments. ... 

Specific tests of adhesion are described in more detail under the following articles Blister test, Climbing drum peel test, Fracture mechanics. Napkin ring test. Peel tests. Rubber to metal bonding - testing. Shear tests. Tensile tests. Wedge test and in Refs. [1-5] see also Standards for adhesives and adhesion and Appendix. 

As described in Standards for adhesives and adhesion, up-to-date standards lists can be obtained on line from the standards organizations of which some of the principal ones are ... 

Standards for adhesives and adhesion S MILLINGTON Discussion of scope and background to national standards... 

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