Laboratory testing and certification 

To ascertain that our products perform and to certify them to the relevant European and Global standards, we test them in various different ways in both physical garment tests and controlled tests in internal and external laboratory environments.

Laboratory testing and certification 

To ascertain that our products perform and to certify them to the relevant European and Global standards, we test them in various different ways in both physical garment tests and controlled tests in internal and external laboratory environments.

BS7209 / ASTM E 96 (upright cup method) 


Tests are conducted in a wind tunnel which is housed in an environmental chamber. The air temperature in the chamber is 23±0.5˚C, and the dew point temperature is 12±1˚C (50% relative humidity). The air velocity in the wind tunnel is 2.8±0.25 m/s. Six circular specimens of 7.4 cm diameter are cut from the fabric. Each specimen is placed on a 155 ml aluminium cup that is filled with 100 ml of distilled water, covered with a gasket, and then clamped into position. Coated or laminated fabrics are placed with the coated or laminated side facing the water in the cup. Each cup is first weighed to the nearest 0.001g and then placed inside the wind tunnel. Subsequent weighings are made at 3, 6, 9, 13, 23, 26, and 30 hours after placement in the chamber. The water vapor transmission rate (WVTR) is calculated using the following formula, where G = weight change (g), t = time during which G occurred, G/t = slope of the straight line for weight loss per unit time (g/h), and A = test area (m²).

WVTR = G/t
A

BS7209 / ASTM E 96 (upright cup method) 


Tests are conducted in a wind tunnel which is housed in an environmental chamber. The air temperature in the chamber is 23±0.5˚C, and the dew point temperature is 12±1˚C (50% relative humidity). The air velocity in the wind tunnel is 2.8±0.25 m/s. Six circular specimens of 7.4 cm diameter are cut from the fabric. Each specimen is placed on a 155 ml aluminium cup that is filled with 100 ml of distilled water, covered with a gasket, and then clamped into position. Coated or laminated fabrics are placed with the coated or laminated side facing the water in the cup. Each cup is first weighed to the nearest 0.001g and then placed inside the wind tunnel. Subsequent weighings are made at 3, 6, 9, 13, 23, 26, and 30 hours after placement in the chamber. The water vapor transmission rate (WVTR) is calculated using the following formula, where G = weight change (g), t = time during which G occurred, G/t = slope of the straight line for weight loss per unit time (g/h), and A = test area (m²).

WVTR = G/t
A

EN 15496:2004 or JIS L 1099
(desiccant inverted cup method)


A solution of potassium acetate is used to fill two-thirds of a cup. The solution acts as a desiccant and generates 23% humidity on one side of the fabric. Once the potassium acetate solution is added, PTFE film is placed over the cup and fixed into place.

Three 20 cm x 20 cm square specimens are then cut from the fabric. Each specimen is placed on the test piece supporting frame. Coated or laminated shell fabric are placed such that the coated or laminated side faces away from the desiccant. Another piece of the PTFE film is placed on top of the fabric specimen and secured to the frame. The test piece frame assembly is placed in a floating position in a water tank of temperature 23˚C.

diagram showing: Desiccant inverted cup assembly (fabric is between water and desiccant)

Figure 1. Desiccant inverted cup assembly (fabric is between water and desiccant)

The mass of the test body with the film side upwards is measured. Then, the test body is im-mediately overturned and placed in the supporting frame. The entire assembly is placed in a constant temperature apparatus that circulates air at 30±2°C. After 15 minutes, the test body is taken out of the constant temperature apparatus and weighed.

The WVTR is calculated using the following formula.

P = 4(a₁ – a₀)
S

where a₁ = mass of the test body after the test (g), a₀ = mass of the test body before the test (g), P = rate of water vapor transmission (g/h/m²), and S = water vapor permeable area (m²). The results are averaged from three specimens and converted to g/24h/m².

EN 15496:2004 or JIS L 1099
(desiccant inverted cup method)


A solution of potassium acetate is used to fill two-thirds of a cup. The solution acts as a desiccant and generates 23% humidity on one side of the fabric. Once the potassium acetate solution is added, PTFE film is placed over the cup and fixed into place.

Three 20 cm x 20 cm square specimens are then cut from the fabric. Each specimen is placed on the test piece supporting frame. Coated or laminated shell fabric are placed such that the coated or laminated side faces away from the desiccant. Another piece of the PTFE film is placed on top of the fabric specimen and secured to the frame. The test piece frame assembly is placed in a floating position in a water tank of temperature 23˚C.

diagram showing: Desiccant inverted cup assembly (fabric is between water and desiccant)

Figure 1. Desiccant inverted cup assembly (fabric is between water and desiccant)

The mass of the test body with the film side upwards is measured. Then, the test body is im-mediately overturned and placed in the supporting frame. The entire assembly is placed in a constant temperature apparatus that circulates air at 30±2°C. After 15 minutes, the test body is taken out of the constant temperature apparatus and weighed.

The WVTR is calculated using the following formula.

P = 4(a₁ – a₀)
S

where a₁ = mass of the test body after the test (g), a₀ = mass of the test body before the test (g), P = rate of water vapor transmission (g/h/m²), and S = water vapor permeable area (m²). The results are averaged from three specimens and converted to g/24h/m².

Evaporative resistance
(ISO 11092, ISO 1999, and ASTM F 1868) 

This test measures the amount of power it takes to keep the plate heated to skin temperature when water vapor is evaporating from the surface of the plate and diffusing through the fabric to the environment.

Three 50.8 cm x 50.8 cm square specimens are cut from fabric. A PTFE liquid barrier is placed on the plate to prevent water from contacting the fabric, ensuring that only water vapor contacts the fabric sample. Each test specimen is placed on the horizontal and flat plate orientated with the side of fabric normally encountering more water vapor facing the hot plate.

The plate temperature and the air temperature are controlled at 35 ± 0.5°C by a main heater and a set of guard and bucking heaters that eliminate both lateral and axial flow from the main heater. A dew point temperature of 19°C is used to achieve 40% relative humidity. A vertical flow of air from a hood is maintained at 1.0 m/s. 

Diagram showing sweating hot plate

Figure 2. Sweating Hot Plate

When the system reaches steady state, the test setup stays at equilibrium for 1 hour. The basic equation for calculating the total resistance to evaporative heat transfer provided by the liquid barrier, fabric, and air film is:

R e,t = (Ps – Pa ) · A
H
where Re,t = total resistance to evaporative heat transfer provided by the fabric system and air (m²Pa/W), A = area of test specimen (m²), Ps = water vapor pressure at the plate surface (Pa), Pa = water vapor pressure in the air (Pa), and H = power input.

Evaporative resistance
(ISO 11092, ISO 1999, and ASTM F 1868) 

This test measures the amount of power it takes to keep the plate heated to skin temperature when water vapor is evaporating from the surface of the plate and diffusing through the fabric to the environment.

Three 50.8 cm x 50.8 cm square specimens are cut from fabric. A PTFE liquid barrier is placed on the plate to prevent water from contacting the fabric, ensuring that only water vapor contacts the fabric sample. Each test specimen is placed on the horizontal and flat plate orientated with the side of fabric normally encountering more water vapor facing the hot plate.

The plate temperature and the air temperature are controlled at 35 ± 0.5°C by a main heater and a set of guard and bucking heaters that eliminate both lateral and axial flow from the main heater. A dew point temperature of 19°C is used to achieve 40% relative humidity. A vertical flow of air from a hood is maintained at 1.0 m/s. 

Diagram showing sweating hot plate

Figure 2. Sweating Hot Plate

When the system reaches steady state, the test setup stays at equilibrium for 1 hour. The basic equation for calculating the total resistance to evaporative heat transfer provided by the liquid barrier, fabric, and air film is:

R e,t = (Ps – Pa ) · A
H
where Re,t = total resistance to evaporative heat transfer provided by the fabric system and air (m²Pa/W), A = area of test specimen (m²), Ps = water vapor pressure at the plate surface (Pa), Pa = water vapor pressure in the air (Pa), and H = power input.

Bespoke Laboratory Testing

We offer bespoke testing to assist with your apparel development projects. This involves comparisons of your product to ensure you can take your garment to the next level in comfort and performance. 

Bespoke Laboratory Testing

We offer bespoke testing to assist with your apparel development projects. This involves comparisons of your product to ensure you can take your garment to the next level in comfort and performance.