Additional Fabric Physical Tests
RESISTANCE TO BLOCKING STABILITY TO HEAT -ISO 25978:1990.
Test specimens are arranged in pairs, back to back, face to face and back to face between two glass plates, then exposed in an oven at 70+/- 2 ºC for 3 hours under a 5.0 kg mass.
After cooling for an hour the specimens are separated and examined for adherence or peeling of the coatings. The sample is classified according to the worst rating obtained.
No Blocking – coated surfaces separate without any evidence of adhering.
Slight Blocking – some adherence of coated surfaces takes place on separation but without any damage to the coating.
Blocking – the coated surfaces are difficult to separate ; the coating or part of the coating is removed on separation.
RESISTANCE TO WATER PENETRATION BS EN 20811: 1992 (1996) (ISO 811: 1981)
Textiles – Determination of resistance to water penetration – Hydrostatic pressure test.
The hydrostatic head supported by the fabric is a measure of the opposition to the passage of water through the fabric. A specimen of 100cm2 (113mm diameter), is subjected to a water pressure, which is applied from below to the face of the specimen, at a rate of increase of 60 ± 0.5cm per minute and a temperature of 20 +/- 2 C. The pressure at which the water penetrates at the third point ( or 3rd drop formation) is noted. Five specimens are tested and the mean determined.
EN1149-5:2008
Determination of Surface Resistivity EN1149-1:2006
The sample is conditioned and tested at 23 ± 1ºC and 25 ± 5% relative humidity.
The surface resistivity of the sample is determined according to the method specified in EN 1149-1:2006.
One surface must show a Surface Resistance of ≤ 2.5 x 109 ohms.
Determination of Induction Decay Time EN1149-3:2004
The sample is conditioned and tested at 23 ± 1ºC and 25 ± 5% relative humidity.
The charge decay time and shielding effect are measured according to BS EN 1149-3: 2004 Method 2 induction charging and a figure of less than 4 seconds must be recorded for the half decay time and or the shield factor of > 0.2.
