Factors Affecting Color Measurement Results Of Textile Fabrics

< p > < strong > moisture content < /strong > /p >

The moisture content of < p > > a href= "//www.sjfzxm.com/news/index_c.asp" > fabric < /a > has a great influence on the result of color measurement, so it is necessary to adjust the moisture content of the sample so that the moisture content of the sample is relatively stable.

Humidity control should be carried out indoors with constant temperature and humidity to ensure that all samples have enough time to achieve constant moisture content.

Among them, most hygroscopicity fabrics need several hours of wetting time. Besides, the environmental conditions also affect the moisture content of the samples.

During the determination period, the humidity control state of the sample should be maintained as far as possible.

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< p > strong > diaphaneity < /strong > /p >

< p > most of the fabrics are pparent to a certain extent. Therefore, the test should be laminated until the light is opaque.

The results of the white board and the blackboard on the back of the stacked specimens are the same, indicating that the number of folding layers is enough.

If other problems are caused by multilayer soft materials, white materials or porcelain plates with fixed layers without fluorescent whitening agents can be lined on the back. The same backing material is usually used.

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< p > < strong > fluorescence < /strong > /p >

< p > a UV absorbing filter is usually inserted between the light source and the sample so as to effectively eliminate the ultraviolet light which can cause fluorescence. However, the method may result in inconsistent results with visual observation.

Therefore, this method can only be used in the case of ultraviolet radiation induced fluorescence.

Although the results of the instrument controlling UV energy are consistent with visual observations, these results are difficult to reproduce on other non similar instruments.

When the sample band has fluorescence properties, all specimens for comparison should be measured within the same time interval (within 1 hours), and can not be used as a basis for comparison of pre determined data (standards and samples).

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< p > < strong > a href= < //www.sjfzxm.com/news/index_c.asp > hardness > /a > /strong > /p >

< p > when the fabric is soft, the sample is easy to extend into the light pmitting hole of the tester, thus affecting the test results.

The specimen should be flat, with a rigid structure on the back and a sufficient thickness to eliminate the effect of pparency. Some samples, especially fibers and yarns, can be reproducible when measured with spectrophotometer. However, the cleanliness and material content of the glass must be controlled. The specimen should be placed on a plate or other steel frame. The back structure should be neutral color (white, gray or black), so that all the test results of the test specimen should be reproduced and the opaque condition should be observed. When the < a href= "//www.sjfzxm.com/news/index_c.asp" > yarn > /a > and the filament sample are wound on the board, it is necessary to control the direction of the tension so that the results can be reproduced. Therefore, the following methods can usually be used to eliminate the effect: Determination

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< p > < strong > sensitivity to light and heat < /strong > < /p >

< p > samples with light or heat sensitivity are best measured in an instantaneous exposure colorimeter.

The flash instrument and the instrument with automatic shutter can provide the sample exposure timing mechanism.

When measuring these samples, do not use the instrument to scan the visible light (complete a unit measurement for seconds).

The total sample preparation should include protective measures for limiting the exposure of samples before testing.

The instrument for monochromatic sample is also suitable for the determination of these similar samples.

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< p > < strong > small area sample < /strong > < /p >.

< p > on the colorimeter, small samples should be used to observe the small area. The average value of the measured results should be read to improve the measurement accuracy.

The specimen smaller than the area of the instrument can not be measured.

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< p > < strong > the surface structure of the specimen is < /strong > < /p >.

< p > the appearance color separation ability of the instrument is the advantage in the dye formulation, but the disadvantage in the application of quality control.

The only effective way to measure the color of the specimen is to place the specimen behind the glass and apply sufficient pressure to eliminate the difference in surface structure.

When glass is used for non rigid specimens, the same measures and conditions should be adopted.

When the surface structure leads to directional change, the number of samples can be determined as a multiple of 4, rotating 90 degrees after each measurement, and then averaging all the measured results in order to produce a set of individual chromaticity values.

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< p > < strong > color difference < /strong > /p >

< p > when the color of the sample is not uniform, the average value (the average value of the spectral value of the spectrophotometer or the three stimulus value of the colorimeter) should be measured to achieve consistent and reproducible results.

This requires a large amount of data to be chosen for window selection.

When the test is repeated at any part of the sample, the average number should be reproducible.

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