Testing of adhesives

2) The performance in the actual adhesive joint that is formed between substrates Generally the following adhesive properties are determined  

More important, however, is the performance of the adhesive in an actual joint. Standard test specimens are bonded under standard conditions and subjected to destructive tests. The load values of these tests give information on the adhesive strength between two bonded substrates. Standard destructive test methods are  

A) Tensile strain B) Shear strain C) Peel strain. 

The static test can be carried out with standard tensile testers that cover the appropriate force range, optionally with a data recorder to obtain a force plot. Dynamic tests require special vibrating devices with constant loads. After the destructive test further information can be gathered from the test specimen. The nature of the break is an important indication of the quality of a bond line. There are three types of ftiilure  

A combination of the above breakage patterns is possible. This is then indicated by a percentage figure (e.g., 60 % cohesive, 40 % adhesive failure). The above tests are also performed with exposure of the test specimens to extreme environments. Bonds are preferably tested for their resistance to  

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Acoustic emission test of adhesive joints of the carbon plastic UKN-5000. 

ASTM D 896-84, Standard Test Method for Resistance of Adhesive Bonds to Chemical Reagents, specifies the testing of adhesive joints for resistance to solvents and... 

Anderson, G. P. Analysis and Testing of Adhesive Bonds Academic ... 

Anderson, G. P. Bennett, S. J. DeVries, K. L. "Analysis and Testing of Adhesive Bonds" Academic Press New York, 1977. 

Gagliano, J. M., "An Improved Method for the Fracture Cleavage Testing of Adhesively-Bonded Wood," Wood Science and Forest Products. Virginia Tech, Blacksburg, VA. 2001. 

Nondestructive Testing of Adhesive Curing in Class-Metal Compounds by Unilateral NMR... 

Titania and Ti02/Si02 (Unmodified and Modified) Used as Fillers to Ethyl Cellulose and Nitrocellulose on the Tests of Adhesion, UV Stability, Corrosion Resistance, and Water Absorption of Filled Films... 

G. P. Anderson, S. J. Bennett, and K. L. DeVries, Analysis and Testing of Adhesive Bonds, Academic Press, New York, 1981. 

Analysis of interfaces between materials, especially for failure analysis after aging and testing of adhesively bonded systems Study of the cure of adhesives. 

Rokhlin SI, Marom D. Nondestmctive testing of adhesively bonded joints. J Acoust Soc Am 1990 87(2) 532-42. 

The third phenomenon, that of detachment of the particles from each other by applying a pull-off force, is the test of adhesion which is most familiar to us. We increase the tension force applied to the particles until they just come apart, and define that force as the adhesion force. A large force means large adhesion. However, this is a very difficult experiment to carry out because the final detachment is an instability which is hard to reproduce exactly each time. Thus, many different values of adhesion can be found for the same samples in such tests, depending on the rate of loading, the precise moment of detachment, etc., leading to considerable unreliability in such measurements. 

Figure 14.1. Pragmatic industry tests of adhesion (a) indenting, cutting and scratching a surface coating (b) bending (c) impact.

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