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May 2013 - About the thixotropic penetrant materials

Written by Administrator
Friday, 12 April 2013 10:27

Thixotropic liquid penetrant products are mentioned in several of our papers(1)(2)(3).
These penetrant materials were invented by the British Norman Henry HYAM (1918-2000) who filed a patent in 1973 (4), and have been placed on the market this same year(5).

However, we are surprised that they still seem rather unknown by some people who think that these penetrant materials have a non-negligible impact on the environment.

In one of our recent Editorials(6), we reminded our readers of the fact that using thixotropic penetrant materials reduces the amount of products to be recycled or recovered for destruction.

One of the advantages of the thixotropic penetrant materials is that they do not flow and they stay as "glued", as a gel would, on the area to be inspected on which they were applied, usually by brushing.
The excess penetrant is removed by wiping with clean, lint-free tissue paper or rag either dampened with water or, if using a post-emulsified thixotropic penetrant, soaked with a thixotropic emulsifier.
The developers are the same as those used for non-thixotropic penetrants.

Therefore, the impact of thixotropic penetrant materials on the environment is reduced to a minimum: the used tissue papers and rags can simply be incinerated. This makes them to be considered to carry out inspections on site or in confined areas.


(1) Pierre CHEMIN and Patrick DUBOSC, PT products for special applications, DPCnewsletter N° 017, October 2009: on our Website.

(2) Pierre CHEMIN and Patrick DUBOSC, Some Penetrant Testing industrial uses, November 2010: on our Website.

(3) Pierre CHEMIN and Patrick DUBOSC, Guide for good practices in PT: A help to choose the most suitable technique, April/May 2012: on our Website.

(4) British Patent specification N° 1 315 121, Improvements in or relating to processes and materials for the detection of flaws and discontinuities in an article. Complete Specification published on April 26, 1973.

(5) Pierre CHEMIN and Patrick DUBOSC, Penetrant Testing history, June 2008: on our Website.

(6)Pierre CHEMIN and Patrick DUBOSC, Some limitations of the techniques supposed to replace PT and MT, Editorial, February 2013: on our Website.

Last Updated ( Friday, 12 April 2013 11:00 )