GB/T 251-2008 English PDF (GBT251-2008)

Delivery: 3 seconds. Download true-PDF + Invoice.
Get QUOTATION in 1-minute: Click GB/T 251-2008
Historical versions: GB/T 251-2008
Preview True-PDF (Reload/Scroll if blank)

GB/T 251-2008: Textiles -- Tests for colour fastness -- Grey scale for assessing staining
GB/T 251-2008
Textiles.Tests for colour fastness.Grey scale for assessing staining
ICS 59.080.01
W04
National Standards of People's Republic of China
GB/T 251-2008/ISO 105-A03.1993
Replace GB 251-1995
Textile color fastness test
Gray stain card for assessing staining
(ISO 105-A03.1993, IDT)
Released on.2008-08-06
2009-06-01 implementation
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
China National Standardization Administration issued
Foreword
This standard uses the translation method equivalent to ISO 105-A03.1993 "Textile fastness test A03 part. evaluation of stained ash
Color Sample Card (English version) and its technical corrigendum 2.2005.
This standard has made the following editorial changes.
--- "ISO 105 this part" is replaced by the word "this standard";
--- Removed the preface to ISO 105-A03.1993;
--- The contents of ISO 105-A03.2005-TechnicalCorrigendum2 are included in the relevant provisions.
This standard replaces GB 251-1995 "Assessing the Gray Sample Card for Staining". The main changes in this standard compared with GB 251-1995 are as follows.
--- The standard name was changed to "the gray color card for staining of textiles for color fastness test";
--- Adjusted from mandatory standards to recommended standards;
--- Increased the background and cover material color requirements when using the gray sample card.
This standard was proposed by the China Textile Industry Association.
This standard is under the jurisdiction of the Basic Branch of the National Textile Standardization Technical Committee (SAC/TC209/SC1).
This standard was drafted. Shanghai Textile Industry Technology Supervision Institute, Shanghai Textile Science Research Institute.
The main drafters of this standard. Chen Xiaocheng, Zhang Zhifeng, Wang Zhongzhao.
The previous versions of the standards replaced by this standard are.
---GB 251-1964, GB 251-1984, GB 251-1995.
GB/T 251-2008/ISO 105-A03.1993
Textile color fastness test
Gray stain card for assessing staining
1 range
This standard specifies the gray sample card for assessing the degree of staining of the lining fabric in the test of the color fastness of the textile and the method of its use. Provided by this standard
The accurate color measurement interval value of the gray sample card can be used as a permanent record for the newly produced gray sample card and the gray sample card that may change.
For comparison purposes.
2 Principle
2.1 The basic gray sample card, that is, the five-step gray sample card is composed of five pairs of matt gray or white cards (or gray and white cloth), according to the perception
The color difference is five levels of color fastness, namely 5, 4, 3, 2, 1. Add one half grade to each of the two grades, namely 4-5, 3-4, 2-3.
1-2, it is expanded into a nine-speed card. The first composition of each pair is white, and the second composition only has a color fastness of 5 and is consistent with the first composition.
The second components of the other pairs are sequentially deepened, the color difference is gradually increased, and the chromatic aberration at each level is determined by the chromaticity. The overall color is specified as follows.
2.2 The paper or cloth shall be white or neutral gray and shall be measured with a spectrophotometer under specularly reflected light.
set. Chromaticity data should be calculated using the CIE 1964 supplemental standard chromaticity system (10° observer) and D65 illuminator.
2.3 The tristimulus value Y of each pair of first components shall not be less than 85.
2.4 The color difference between the second component and the first component of each pair shall comply with the following provisions.
Fastness level CIELAB color difference tolerance
5 0 0.2
(4-5) 2.2 ±0.3
4 4.3 ±0.3
(3-4) 6.0 ± 0.4
3 8.5 ±0.5
(2-3) 12.0 ±0.7
2 16.9 ±1.0
(1-2) 24.0 ± 1.5
1 34.1 ±2.0
The values in parentheses apply only to the nine-step gray sample card.
2.5 Use of gray sample card. a piece of unstained lining fabric (original lining) and a part of the combined sample in the color fastness test (post-test paste)
The linings are placed side by side in the same plane and the gray sample cards are placed close to the same plane. The background should be neutral gray color, approximate
The color is changed between the gray level card level 1 and level 2 (approximating the Munsell color card N5). If you want to avoid the impact of the backing on the appearance of the textile, you can take it without
Two or more layers of color undyed textile are lined under the original lining and the post-test lining. The northern hemisphere is illuminated by the north sky and the southern hemisphere is illuminated by the south sky.
Irradiation, or use an equivalent source of 600lx and above. The incident light should be at an angle of about 45° to the surface of the textile, and the viewing direction is substantially perpendicular to the textile table.
surface. The color difference between the original lining and the post-test lining was visually evaluated according to the grade difference of the gray sample card.
The appearance color of the sample is affected by the background and the color of the covering material when viewed. In order to obtain reliable results, cover the original lining
The panels that are affixed to the test cover should be of the same color. Neutral background materials and sets should be used, if used properly
Or black sets of boards are also available. For example, if the black slab is used after the cover is applied, the original lining should also use the same black.
material. If only a single neutral color covering is used, the post-test lining and the original lining should be completely enclosed.
GB/T 251-2008/ISO 105-A03.1993
If you use a five-grade gray sample card, the perceived color difference between the original lining and the post-test lining is equivalent to a gray card.
When the color difference is observed, the series is used as the color fastness level of the sample. If the perceived color difference between the original lining and the post-test lining is close to
In the middle of a certain level of the gray sample card, the stain fastness level of the sample is evaluated as an intermediate level, such as 4-5 or 2-3. Only after the test
It can be set to 5 when there is no perceived color difference between the lining and the original lining.
If a nine-grade gray sample card is used, the perceived color difference between the original lining and the post-test lining is closest to that of the gray-like card.
In some cases, when the color difference is observed, the number of levels is used as the color fastness level of the sample. There is no perceived color difference between the post-test lining and the original lining.
It can be set to level 5.
After the rating of a batch of samples is made, each pair of original linings and post-test linings rated as the same level are compared with each other. This can
See if the ratings are consistent, as any errors in ratings will be particularly prominent at this time. If the degree of chromatic aberration of a pair and other groups in the same group
When the pairs are inconsistent, it is advisable to re-evaluate the gray sample card and, if necessary, change the color fastness level originally assessed.
GB/T 251-2008/ISO 105-A03.1993