QB/T 2727-2017Leather - Tests for color fastness - Color fastness to artificial light: xenon art fading lamp test (English PDF)

4.1 Reference materials

4.1.1 Blue wool reference materials, complying with the provisions of GB/T 730.

4.2 Equipment

4.2.1 Xenon arc lamp light resistance testing machine (air-cooled or

water-cooled)

The sample and the blue wool reference materials can be exposed in any of

the following equipment (see 4.2.1.1 and 4.2.1.2) at the same time. The light

source is a xenon arc lamp. The difference in light intensity on the light receiving

surface of the sample and the blue wool reference materials shall not exceed

±10 % of the average value.

4.2.1.2 Water-cooled xenon arc lamp light resistance testing machine

Water-cooled xenon arc lamp light resistance testing machine shall meet the

following conditions.

4.2.2 Temperature sensor

4.2.2.1 Black plate thermometer (BPT), including a metal plate with a size of at

least 45 mm × 100 mm. The temperature is measured by a temperature

measuring device, and the thermal measurement point is located in the center

of the metal plate. The side of the metal plate facing the light source is black,

so that the reflectivity of the light reaching the sample on the blackboard is less

than 5 %.

4.2.2.2 Black scale thermometer (BST), including a stainless steel plate with a

size of about 70 mm × 30 mm, a thickness of about 0.5 mm. The temperature

is measured by a temperature measuring device.

4.2.2.3 Irradiance monitor. Since the irradiance of the sample surface changes

as a function of the xenon lamp, light intensity and the distance from the xenon

lamp to the sample, the consistency of exposure shall be controlled by the

irradiance monitor.

5.1 The size of the sample shall meet the size of the sample holder that comes

with the instrument. The size of the sample varies with the number of samples

and the size and shape of the sample holder provided by the instrument. One

sample holder can be used to test one sample or a set of samples.

5.3 In water-cooled equipment, the sample clip should be placed the sample of

about 70 mm × 120 mm. The blue wool reference materials shall be placed on

the white paper card backing for exposure. If necessary, the sample can also

be placed on the white paper card.

5.4 The size and shape of the sample shall be the same as the blue wool

reference materials, so as to avoid errors of higher ratings in comparing the

sample with a larger area to the blue wool reference with a smaller area when

visually rating the exposed and unexposed parts.

7.1 CHECK whether the equipment is in good operating condition and whether

clean, effective xenon arc lamps are installed.

7.2 PLACE the sample clip containing the sample on the sample holder in the

equipment. The empty space on the sample holder shall be filled with the

sample clip equipped with a white hard card.

7.3 ADJUST the controller on the equipment to obtain the specified humidity

and black mark thermometer temperature or black plate thermometer

temperature.

7.4 TURN on the equipment, and RUN continuously until the test is completed,

unless it is necessary to clean the xenon lamp or the lamp and the inner and

outer light filter have reached the maximum service life and need to be replaced.

8.1 Method 1

The basic feature of this method is to control the exposure cycle by checking

the sample, so each sample needs to be equipped with a set of blue wool

reference materials.

8.1.1 ARRANGE the sample and the blue wool reference materials in parallel,

and PLACE the covering on the sample and the blue wool reference materials.

The covering shall make the exposed part no less than 1/3 of the width of the

sample holder and no more than 1/2 of the width of the sample holder.

8.1.4 COVER the sample and the blue wool reference materials with another

covering, continue to EXPOSE until the color difference between the exposed

and unexposed parts of the sample is equal to the grey scale level 3, and

EVALUATE the color fastness to light at this time. The covering shall completely

cover the covering in 8.1.1, at the same time it shall make the second-stage

exposure about 1/2 of the exposure width in 8.1.1.When the fade of the blue

wool reference material 7 reaches the grey scale level 4 first, the exposure can

be terminated.

8.2 Method 2

This method is suitable for testing a large number of samples at the same time.

Its basic feature is to control the exposure cycle by checking the blue wool

reference materials. It only requires a set of blue wool reference materials to

test a batch of samples with different color fastness to light, to save blue wool

reference materials.

8.2.1 ARRANGE the sample and blue wool reference materials in parallel.

8.2.2 COVER 1/5 ~ 1/4 of the total length of the sample and the blue wool

reference materials with covering.

8.2.3 EXPOSE according to the exposure conditions, and LIFT the covering

from time to time to check the lighting effect of the blue wool reference materials.

8.2.9 Continue to expose until one of the following conditions occurs.

8.2.10 EVALUATE the color fastness to light at this time.

8.3 Method 3

This method is suitable for checking whether it is consistent with a certain

performance, allowing the sample to be exposed with only two pieces of blue

wool reference materials, where one blue wool reference material is of the

minimum allowable color fastness and another blue wool reference material is

of a lower color fastness. Expose continuously under the specified exposure

conditions until the segmented surface of the blue wool reference material with

the minimum allowable color fastness equals to the color difference of the grey

scale level 4 (first stage) and level 3 (second stage)

8.4 Method 4

This method is suitable for checking compliance with an agreed reference

sample, allowing the sample to be exposed only with this reference sample.

Expose continuously until the color change of the reference sample is equal to

the color difference of the grey scale level 4 and/or level 3.

8.5 Method 5

This method is suitable for checking whether it meets the approved irradiation

energy value. The sample can be exposed alone or together with the blue wool

reference materials until the specified irradiation amount is reached.

9.1 On the basis that the color difference between the exposed and unexposed

parts of the sample is equal to the grey scale level 3, the final evaluation of the

level of color fastness to light is made. On the basis that the color difference

between the exposed and unexposed parts of the white leather reaches the

grey scale level 4, the final evaluation of the level of color fastness to light is

made.

9.4 If different evaluations are obtained on the color difference in different

stages, the arithmetic mean value may be taken as the color fastness to light

of the sample, which is expressed in the nearest half or full level. When the

arithmetic mean of the level is 1/4 or 3/4, it shall take the adjacent higher half

or one level.

9.5 In order to avoid wrong evaluation of color fastness to light due to

photochromism, the sample shall be placed in a dark place before being

evaluated for color fastness to light, and it shall be kept at room temperature

for 24 h.

9.6 If the color of the sample is easier to fade than the blue wool reference

material 1, it is rated as level 1.

9.7 In Method 3 (8.3), the sample is exposed with the specified blue wool

reference materials, and then the color change of the sample and the blue wool

reference materials are compared and rated.

9.8 In Method 4 (8.4), the sample is exposed with an agreed reference sample,

and then the color change of the sample and the reference sample are

compared and rated. If the color change of the sample is not greater than that

of the reference sample, the color fastness to light is determined as

"conforming"; if the color change of the sample is greater than that of the

reference sample, the color fastness to light is determined as "non-conforming".

9.9 The evaluation of color fastness in Method 5 (8.5) is to use the color-

changing grey scale in GB/T 250 for comparison or use blue wool reference

materials for comparison.

4.1 Reference materials

4.1.1 Blue wool reference materials, complying with the provisions of GB/T 730.

4.2 Equipment

4.2.1 Xenon arc lamp light resistance testing machine (air-cooled or

water-cooled)

The sample and the blue wool reference materials can be exposed in any of

the following equipment (see 4.2.1.1 and 4.2.1.2) at the same time. The light

source is a xenon arc lamp. The difference in light intensity on the light receiving

surface of the sample and the blue wool reference materials shall not exceed

±10 % of the average value.

4.2.1.2 Water-cooled xenon arc lamp light resistance testing machine

Water-cooled xenon arc lamp light resistance testing machine shall meet the

following conditions.

4.2.2 Temperature sensor

4.2.2.1 Black plate thermometer (BPT), including a metal plate with a size of at

least 45 mm × 100 mm. The temperature is measured by a temperature

measuring device, and the thermal measurement point is located in the center

of the metal plate. The side of the metal plate facing the light source is black,

so that the reflectivity of the light reaching the sample on the blackboard is less

than 5 %.

4.2.2.2 Black scale thermometer (BST), including a stainless steel plate with a

size of about 70 mm × 30 mm, a thickness of about 0.5 mm. The temperature

is measured by a temperature measuring device.

4.2.2.3 Irradiance monitor. Since the irradiance of the sample surface changes

as a function of the xenon lamp, light intensity and the distance from the xenon

lamp to the sample, the consistency of exposure shall be controlled by the

irradiance monitor.

5.1 The size of the sample shall meet the size of the sample holder that comes

with the instrument. The size of the sample varies with the number of samples

and the size and shape of the sample holder provided by the instrument. One

sample holder can be used to test one sample or a set of samples.

5.3 In water-cooled equipment, the sample clip should be placed the sample of

about 70 mm × 120 mm. The blue wool reference materials shall be placed on

the white paper card backing for exposure. If necessary, the sample can also

be placed on the white paper card.

5.4 The size and shape of the sample shall be the same as the blue wool

reference materials, so as to avoid errors of higher ratings in comparing the

sample with a larger area to the blue wool reference with a smaller area when

visually rating the exposed and unexposed parts.

7.1 CHECK whether the equipment is in good operating condition and whether

clean, effective xenon arc lamps are installed.

7.2 PLACE the sample clip containing the sample on the sample holder in the

equipment. The empty space on the sample holder shall be filled with the

sample clip equipped with a white hard card.

7.3 ADJUST the controller on the equipment to obtain the specified humidity

and black mark thermometer temperature or black plate thermometer

temperature.

7.4 TURN on the equipment, and RUN continuously until the test is completed,

unless it is necessary to clean the xenon lamp or the lamp and the inner and

outer light filter have reached the maximum service life and need to be replaced.

8.1 Method 1

The basic feature of this method is to control the exposure cycle by checking

the sample, so each sample needs to be equipped with a set of blue wool

reference materials.

8.1.1 ARRANGE the sample and the blue wool reference materials in parallel,

and PLACE the covering on the sample and the blue wool reference materials.

The covering shall make the exposed part no less than 1/3 of the width of the

sample holder and no more than 1/2 of the width of the sample holder.

8.1.4 COVER the sample and the blue wool reference materials with another

covering, continue to EXPOSE until the color difference between the exposed

and unexposed parts of the sample is equal to the grey scale level 3, and

EVALUATE the color fastness to light at this time. The covering shall completely

cover the covering in 8.1.1, at the same time it shall make the second-stage

exposure about 1/2 of the exposure width in 8.1.1.When the fade of the blue

wool reference material 7 reaches the grey scale level 4 first, the exposure can

be terminated.

8.2 Method 2

This method is suitable for testing a large number of samples at the same time.

Its basic feature is to control the exposure cycle by checking the blue wool

reference materials. It only requires a set of blue wool reference materials to

test a batch of samples with different color fastness to light, to save blue wool

reference materials.

8.2.1 ARRANGE the sample and blue wool reference materials in parallel.

8.2.2 COVER 1/5 ~ 1/4 of the total length of the sample and the blue wool

reference materials with covering.

8.2.3 EXPOSE according to the exposure conditions, and LIFT the covering

from time to time to check the lighting effect of the blue wool reference materials.

8.2.9 Continue to expose until one of the following conditions occurs.

8.2.10 EVALUATE the color fastness to light at this time.

8.3 Method 3

This method is suitable for checking whether it is consistent with a certain

performance, allowing the sample to be exposed with only two pieces of blue

wool reference materials, where one blue wool reference material is of the

minimum allowable color fastness and another blue wool reference material is

of a lower color fastness. Expose continuously under the specified exposure

conditions until the segmented surface of the blue wool reference material with

the minimum allowable color fastness equals to the color difference of the grey

scale level 4 (first stage) and level 3 (second stage)

8.4 Method 4

This method is suitable for checking compliance with an agreed reference

sample, allowing the sample to be exposed only with this reference sample.

Expose continuously until the color change of the reference sample is equal to

the color difference of the grey scale level 4 and/or level 3.

8.5 Method 5

This method is suitable for checking whether it meets the approved irradiation

energy value. The sample can be exposed alone or together with the blue wool

reference materials until the specified irradiation amount is reached.

9.1 On the basis that the color difference between the exposed and unexposed

parts of the sample is equal to the grey scale level 3, the final evaluation of the

level of color fastness to light is made. On the basis that the color difference

between the exposed and unexposed parts of the white leather reaches the

grey scale level 4, the final evaluation of the level of color fastness to light is

made.

9.4 If different evaluations are obtained on the color difference in different

stages, the arithmetic mean value may be taken as the color fastness to light

of the sample, which is expressed in the nearest half or full level. When the

arithmetic mean of the level is 1/4 or 3/4, it shall take the adjacent higher half

or one level.

9.5 In order to avoid wrong evaluation of color fastness to light due to

photochromism, the sample shall be placed in a dark place before being

evaluated for color fastness to light, and it shall be kept at room temperature

for 24 h.

9.6 If the color of the sample is easier to fade than the blue wool reference

material 1, it is rated as level 1.

9.7 In Method 3 (8.3), the sample is exposed with the specified blue wool

reference materials, and then the color change of the sample and the blue wool

reference materials are compared and rated.

9.8 In Method 4 (8.4), the sample is exposed with an agreed reference sample,

and then the color change of the sample and the reference sample are

compared and rated. If the color change of the sample is not greater than that

of the reference sample, the color fastness to light is determined as

"conforming"; if the color change of the sample is greater than that of the

reference sample, the color fastness to light is determined as "non-conforming".

9.9 The evaluation of color fastness in Method 5 (8.5) is to use the color-

changing grey scale in GB/T 250 for comparison or use blue wool reference

materials for comparison.