Now the manufacturers of protective textiles or textile personal protection equipment (PPE) can have their products tested at the Hohenstein Institute in Bönnigheim for the protection they offer against molten metal splash. The experts at the Hohenstein Institute carry out the testing within 10 to 15 working days.
The tests are carried out in accordance with the requirements of DIN EN ISO 9185. To ensure that the results can be reproduced at any time, the test material is acclimatised for 24 hours before testing, in a climate chamber where the temperature and air humidity are set to defined standards.
Then the samples are stretched on a frame in the testing device, over a special PVC film. In this test set-up, any damage to this PVC film represents possible injury to human skin.
According to the specifications in the standard, the PVC film is regarded as damaged if there is a perforation or change to the characteristics of the PVC film extending over at least 5 mm. It is also regarded as damaged if the film develops any pale flecks more than a total of 5 mm in width.
The test measures the amount of molten metal required to cause damage to the PVC film. If there is no detectable damage to the PVC film after the first test, it is repeated with the amount of molten metal increased by 50 g. The test continues with increasing amounts of molten metal until damage is caused to the PVC film. Once this point is reached, the amount of molten metal is reduced again in 10 gram stages until damage is no longer caused.
In this way, the minimum amount of molten metal that will cause damage can be calculated. The highest amount of molten metal that causes no damage, and the lowest amount that does cause damage are recorded and the mean value between these is called the Molten Metal Splash Index, which is accurate to the nearest gram and is the figure that is used to assign the product into a particular class.