ISO 17493: 2016

CLOTHING AND EQUIPMENT FOR PROTECCION AGAINST HEAT

TEST METHOD FOR CONVECTION HEAT RESISTANCE USING A HOT AIR CIRCULATION FURNACE

DEFINITION

This test method allows the evaluation of the heat resistance of materials, protective clothing and equipment.

Samples are suspended in a hot air circulation oven for 5 minutes at the specified test temperature of 180°C or 260°C for 5 minutes. Any visible observations such as charring, deformation, degradation, delamination, brittleness, flaking, hole formation, ignition, melting, separation, or splitting of the sample are recorded and shrinkage is measured.

Observations of degradation, brittleness, splitting, separation, or flaking may be considered subjective and should not be used as pass/fail criteria for a product standard.

EQUIPMENT

Forced air circulation oven, capable of maintaining the test temperature for a period of 5 min and of sufficient internal volume to allow suspension of the test sample
The tests will be carried out at the test temperature specified in the reference standard. Unless otherwise specified, the tests shall be carried out at a test temperature of (180)°C or (260)°C.

The maximum deviation of temperature from the temperature levels specified in:

— 260 °C for each of the nine thermocouples shall not exceed 6.5 °C

— 180 °C for each of the nine thermocouples shall not exceed 4.5 °C.

Rigid, square templates for sizing material test tubes
A 375 mm × 375 mm template shall be used to size flat materials that are subject to shrinkage measurements.
A 150 mm × 150 mm template can be used for flat materials that are not subject to shrinkage measurements.

Stretch frame for measuring shrinkage of knitted materials.

SAMPLES

Test a minimum of three 375mm x 375mm samples cut using the template mentioned above.

PROCEDURE FOR FLAT TEXTILES

Mark the distance between the two marks of each sample with a distance of 275 mm.
Heat oven to specified temperature and stabilize for 30 min.
Suspend the sample by metal hooks at the top and center in the oven for 5 min.
Five minutes after the specified exposure, when necessary, measure the marked dimensions of the specimen to determine the percent shrinkage in both principal directions. Pull the knit fabric swatches to their original dimensions for 10 min, then remove the swatches from the frame and allow the swatches to relax for 10 min before measurement to determine pass/fail.