UNE-EN ISO 12127-2:2008

This part of ISO 12127 describes the test method that allows to evaluate the heat transfer, and the behavior of materials used in protective clothing when hit by small particles metal projections at high temperature, especially when these are trapped. in the folds of clothing in work situations.

The results obtained with this method allow the comparison of the behavior of different materials subjected to the same standardized test conditions.

They do not allow drawing conclusions about the behavior regarding the contact of large splashes of molten iron or other metals, nor predict the behavior of complete garments under industrial conditions.

This test method consists of two phases, which are carried out in order.

The first phase of the method consists in dropping a hot steel cylinder onto a point of the test sample located horizontally, and verifying the formation of a hole.

The second phase consists of measuring the maximum temperature difference of the materials that have passed the first phase.

The test samples must have minimum dimensions of (180 × 25) mm and must be taken from points more than 20 mm from the edges of the piece of material, in an area free of defects.

When the warp/weft direction cannot be determined, samples should be taken in two perpendicular directions.

For phase 1, cut at least 4 samples, 2 in the weft direction and 2 in the warp direction.

For phase 2, cut at least 6 samples, 3 in the weft direction and 3 in the warp direction.

At each end of the sample a hem will be made to allow the installation of the counterweights. The stitch patterns are measured without the tension of the counterweights. The necessary size for the stitch samples must be taken into account since they will be used without counterweights.

Phase 1: Hole formation test

The support block will be used without the calorimeter. The refrigeration system is not necessary at this stage. Proceed according to points a) to c), e), f) and i) to k). this procedure will be repeated until all four samples have been tested. The material is considered to have failed the test if hole formation is found in any of the samples, in which case the phase 2 test is not necessary.

Phase 2: Temperature difference test

The support block will be used with the calorimeter and the refrigeration system. Proceed according to points a) to k) for the six samples cut in two perpendicular directions.

1. Conditioning: Condition the test sample for at least 24 h at a temperature of (20 ± 2) °C and a relative humidity of (65 ± 5) %, and the test will proceed within 3 min after your removal from this environment.
2. Preliminary procedure:
   1. For the oven: check the fit of the thermocouple inside the steel cone at room temperature. The oven will be adjusted so that it maintains a temperature inside the cone of (600 ± 5) ºC during the test.
   2. For the refrigeration unit: the refrigeration unit will be put into operation at least one hour before heating the first steel cylinder, so that a sensor temperature of (20 ± 1) °C is maintained.
3. Test conditions: (20 ±51ºC-15-80 HR).
4. The cone is heated to a temperature of (600±5)º C 5
5. A new cold steel cylinder is inserted into the cone. The cone is reintroduced into the furnace so that the thermocouple is placed back inside the cone 1 cm from the hole in the bottom of the cone. Heat the steel cylinder for (30±5) min.
6. The test pattern is placed on the support block using the counterweights, except in the case of knitted patterns for which counterweights will not be used.
7. It will be verified that the sensor temperature is (20±1)º C.
8. The cone is removed from the oven once the cylinder has been heated for (30±5) min, it is placed in the cone support on the guide. Drop and test sample.
9. Within ten seconds of removing the cone from the oven, the electromagnet is turned on to move the slider inside the cone and release the cylinder onto the sample through the drop guide.
10. The temperature begins to be measured. Record at least the start temperature To, the maximum temperature, Tmax, and the cone temperature Tc.
11. The test will be highlighted if there is a clear difference between AT and the average AT value for all tests on the material.
12. The cone will be removed from its support as soon as the steel cylinder is released from the cone. A new steel cylinder will be inserted inside the cone and the cone will be placed back in the oven for (30 ±5) min. It will avoid cooling the cone.
13. Part 2 of the drop guide will rise once the temperature has started to drop. The adherence of the steel cylinder to the fabric will be verified and the cylinder will be dropped into a small cup, for example. The support block will be put back on. Remove the sample and immediately examine for pinhole formation, sticking, and any modification of the sample.
14. The surface of the sensor and the guide will be cleaned of any ash residue using a small brush. The support block with the sensor and part 2 of the drop guide will be adjusted to its test position, and allowed to cool.
15. Record in the test report for each sample, hole formation, temperature difference, mean value and standard deviation of the six test samples and cone temperatures.

This test standard does not have requirements but they can be taken into account according to the requirements according to EN ISO 11612:2015.