Rubbing sensitivity

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The behavior of a substance (usually an explosive ) towards mechanical stress is called friction sensitivity . The criterion here is that the substance decomposes under the effect of a frictional load with crackling, ignition or explosion.

Test method

The friction test developed by the Federal Institute for Materials Research and Testing (BAM) is used as the test method . Here, the material between two porcelain bodies is loaded with a defined frictional force. This results from the product of the friction path and the weight setting on the test device and is specified in the unit Newton (N).

Classifications

In terms of the Explosives Act and Regulation (EC) No. 440/2008 of the European Commission, a limit value of 360 N applies, below which it is classified as an explosive substance . In addition to testing for impact sensitivity ( drop hammer test ) and the steel case test , the friction test is one of the tests prescribed by the Explosives Act. The test is as Test 3 (b) (i) (BAM friction apparatus) within the test series 3 part of the testing schemes for classifying explosives of Class 1 in the sense of dangerous goods regulations .

Examples

The following table gives an overview of typical rub-sensitive substances. Substances such as ammonium nitrate , dinitrobenzene , nitroglycol , nitroglycerin , picric acid and trinitrotoluene do not react in the rubbing apparatus up to a load of 36 kp or 353 N.

Sensitivity to friction of explosive substances
material Load on the friction pin
kp N
Silver acetylide 0.01 0.1
Hexamethylene triperoxide diamine 0.01 0.1
Lead azide 0.01 0.1
Cyanuric triazide 0.01 0.1
Mercury (II) acetylide 0.01 0.1
Copper acetylide 0.01 0.1
Tricycloacetone peroxide 0.01 0.1
Lead (II) trinitroresorcinate 0.15 1.5
Mercury (II) fulminate (gray) 0.3 3
Mercury (II) fulminate (white) 0.5 5
Tetrazene 0.8 8th
Erythritol tetranitrate 3 30th
Nitropenta 6th 60
Silver (I) oxalate 8th 80
Hexogen 12 120
Strontium azide 12 120
Barium azide 24 240
Tetryl 36 359

swell

  1. ↑ Regulation (EC) No. 440/2008 of the Commission of May 30, 2008 establishing test methods in accordance with Regulation (EC) No. 1907/2006 of the European Parliament and of the Council on the registration, evaluation, authorization and restriction of chemical substances (REACH ), Test method A.14 Explosion hazard.
  2. ↑ H. Koenen, KH Ide: Explosivstoffe. 4, 1956, p. 1.
  3. ↑ H. Koenen, KH Ide In: Explosivstoffe. 9, 1961, pp. 4 and 30.
  4. ^ UN Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria. 5th, revised. Edition. United Nations Publication, New York / Geneva 2009, ISBN 92-1-139087-7 .
  5. ↑ a b J. Köhler, R. Meyer, A. Homburg: Explosivstoffe. 10., completely revised. Edition. Wiley-VCH, Weinheim 2008, ISBN 978-3-527-32009-7 , p. 245.

literature

  • Regulation (EC) No. 440/2008 of the Commission of 30 May 2008 laying down test methods in accordance with Regulation (EC) No. 1907/2006 of the European Parliament and of the Council on the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) , Test method A.14 Explosion hazard
  • UN Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria, Fifth Revisited Edition 2009, United Nations Publication, New York and Geneva, ISBN 92-1-139087-7 .
  • DIN EN-13631-3 Explosives for civil purposes - High explosives - Part 3: Determination of the friction sensitivity of explosives, Beuth Verlag
  • Josef Köhler, Rudolf Meyer, Axel Homburg: Explosives . Wiley-VCH, Weinheim 2008, ISBN 978-3-527-32009-7 .
  • * Thomas M. Klapötke : Chemistry of High-Energy Materials. 3. Edition. Walter de Gruyter, Berlin / Boston 2015, ISBN 978-3-11-043932-8 , pp. 149–153.
  • W. Berthold, U. Löffler: Lexicon of safety-related terms in chemistry. Verlag Chemie, Weinheim 1981, ISBN 3-527-25894-9 .