CUT TEST EXPLAINED

• EUROPEAN CUT TEST EXPLAINED

  EN388:2003 uses the Coup test machine.

  A circular blade rotates as it is dragged back and forth by the test machine across the sample of the glove under a constant 500 gram weight at a constant speed. The test is stopped when the rotating blade cuts through the glove material. The number of cycles (# back and forth) required to cut the material is noted. Then a control fabric (cotton fabric) is tested in order to establish a reference. The number of cycles (# back and forth) is again noted. This test is repeated as follows: cotton - sample – cotton – sample – cotton – sample – cotton – sample – cotton –sample – cotton.

  After these repeated tests, the cut index can be calculated. This is the ratio of the number of cycles required to cause cutting of the test material to the number of cycles required to cut the known standard material (cotton canvas). This Cut Index can be found on the marking of the glove itself. The second number under the pictogram for mechanical protection indicates the cut protection level between 0 and 5. The higher the Cut Index, the higher the cut protection level.

  The disadvantage of this Coup Test is the dulling of the microscopic edge of the blade when testing highly cut protective gloves. Round robin tests indicate many differences between different test labs. The Coup Test tends to give more favourable results with ceramic than steel based engineered yarns. Steel-based engineered yarns will stop the machine due to metal to metal contact and do not necessarily cut through the material while glass fiber makes the material slippery. That is why manufacturers are recommended to also indicate the results of the TDM test further to ISO 13997-1999 for gloves with a Cut Index 4 or 5.

  

• AMERICAN CUT TEST EXPLAINED

  ASTM F1790-05 uses the TDM 100 cut test machine.

  The 2005 version ASTM F-1790-05 test method uses the Tomodynamometer (TDM) test machine to measure the distance traversed by a sharp blade over a test material before it penetrates. The 100 mm straight-edged blade is used only once and it is calibrated before every test. After adding weight to the blade, it is dragged back and forth by the test machine across the sample of the glove at a constant speed. The moment it cuts through the glove sample, it makes contact with the copper strip under the glove sample. This metal-to-metal contact stops the machine. The machine measures the distance the blade traveled to produce a 20mm cut in the material. Then the machine measures the load in grams that a material can withstand a 20 mm cut.

  Five test cycles are completed with 3 different loads (weights) and the distance/weight data are entered into an exponential regression program. This program determines the weight (in grams) that would be required to cause a cut of a distance of 20 mm. The higher the gram weight the higher the cut protection level.

  The 1997 version of this test method is called the ASTM F1790-97 and used the Cut Protection Performance tester (CPPT). Other key differences: the glove sample is adhered to the machine using a mounting tape, the reference distance of the cut is 25 mm and the calibration is lower (500 g in 2005 method). The 1997 results cannot be compared with the results before 2005. Many companies still use the ASTM 1790-97 and the CPPT machine. Beware that results can vary based on the microscopic sharpness of the new blade.

  ANSI/ISEA 105 is the standard that assigns levels according to the gram weights from the ASTM Testing. The ANSI Cut Level is the most common reference for cut protection levels in the USA. Important: it only applies to ASTM F1797-97 and not to ASTM F1790-05. The 2005 standard is not recognized by ANSI/ISEA as it gives lower results than the 1997 method.

  

• INTERNATIONAL CUT TEST EXPLAINED

  ISO 13997-1999 only uses the TDM 100 cut test machine.

  This method is very similar to the ASTM F1790-05 test method with slight changes to the range of lengths achieved from the 3 different weights. The ISO method requires a validation of the calculated weight to be within specification limits. Results are quoted in newton (N).

  The use of the ISO 13997-1999 test method is already mandatory in Europe for gloves with a high cut protection of level 4 or 5.

  The ASTM F1790-05 uses the same machine and many same test features.