GB/T 30127-2013Textiles—Testing and evaluation for far infrared radiation properties (English PDF)

3.1 Far infrared emissivity

The ratio of the normal far-infrared radiation intensity between the specimen and the standard blackbody plate at the same temperature under specified conditions.

4.1 Determination of far-infrared emissivity

Place the standard blackbody plate and the specimen on the hot plate one after the other; adjust the surface temperature of the hot plate to the specified temperature in turn.

4.2 Determination of temperature rise

After the far-infrared radiation source irradiates the specimen at a constant radiation intensity for a certain period of time, measure the temperature rise value of the test surface of the specimen.

6.1 Specimen humidity conditioning and environmental requirements

The humidity shall be conditioned in accordance with the standard atmospheric temperature and humidity environment and procedures as specified in GB/T 6529; there shall be no other heat radiation sources affecting it.

6.2 Pretreatment

6.3 Preparation of specimen

6.3.1 Fiber

When measuring the far-infrared emissivity, open the fiber specimen into a fluffy state; take 0.5 g of fiber and fill it into an open cylindrical metal container which has a diameter of 60 mm and a height of 30 mm. The fiber is completely filled in the container; take at least 3 specimens from each set of sample. When determining the temperature rise, comb the fibers into a fluffy state; evenly spread it to a uniform cylindrical flocculus which has a thickness of about 30 mm and a diameter of more than 60 mm. Take at least 3 specimens from each set of samples.

6.3.3 Sheet samples such as fabrics

Cut at least 3 specimens for emissivity and temperature rise from each sample.

The size of the specimen is not less than 60 mm in diameter. The specimen shall be flat and representative when sampling.

7.1 Determination of far-infrared emissivity

7.1.4 Test the remaining specimens according to the steps in 7.1.3

7.1.2 Place the standard blackbody plate on the test hot plate; record the far-infrared radiation intensity of the standard blackbody I0 after the test value is stable.

7.1.1 Heat the test hot plate to 34 °C

7.2 Test of far-infrared radiation temperature rise

7.2.1 Adjust the distance between the specimen holder and the radiation source, so that the distance between the specimen surface and the radiation source is 500 mm.

7.2.2 Clamp the test surface of the humidity-conditioned specimen in the specimen holder facing the infrared radiation source. Fix the contact of the thermometer sensor at the center of the surface of the irradiated area of the specimen.

7.2.3 Record the initial temperature of the sample surface T0

8.1 Result calculation

8.1.1 Measure the far-infrared radiation intensity of the standard blackbody plate and the specimen according to 7.1; calculate the far-infrared emissivity of each specimen according to formula (1); calculate the average value of the far-infrared emissivity of all specimens as the test result, round it off to 0.01. Where.

8.1.2 According to the measured results in 7.2, calculate the temperature rise of each specimen surface according to formula (2); calculate the average temperature rise of all specimens as the test result; round it off to 0.1 °C.

8.2 Evaluation of far-infrared properties of textiles

For ordinary samples, if the far-infrared emissivity of the specimen is not less than 0.88 and the temperature rise of far-infrared radiation is less than 1.4 °C, the sample has far-infrared properties. For loose samples such as flakes, nonwovens, fleece, the far-infrared emissivity is not less than 0.83, meanwhile the temperature rise of far-infrared radiation is not less than 1.7 °C, the specimens have far-infrared properties.