ISO 105-J01:1997 pdf download – Textiles – Tests for colour fastness
In general, instrument standardization involves measuring a clean white surface of known reflectance factors and calculating (through software built into the instrument or computer program) a series of correction factors which will be applied to subsequent measurements. Some instruments also require a black tile (or light trap), and possibly a grey tile. Each of these materials shall be maintained in its original clean, unscratched condition. Refer to the specific manufacturer’s recommendations for cleaning instructions. The frequency with which this standardization is performed depends on many factors including the type of instrument, the environmental conditions in which the instrument operates, and the required accuracy of the results. For most applications, an interval of 2 h to 4 h is acceptable. Once the standardization step has been performed, it is important to verify the success of the procedure by measuring some coloured materials (verification standards) and comparing the resulting colorimetric values to the original values for these materials. If the measured values do not fall within an acceptable variation from their original values, the standardization is not considered valid.
6.4 Specimen preparation
The ideal specimen to measure is a rigid, non-textured, inert, opaque specimen of uniform colour. Such ideal specimens do not exist in textiles, so it becomes necessary to employ techniques and practices when measuring most textile materials which eliminate or reduce to acceptable levels the effect any specimen characteristics have on the instrumental colour measurement. Specific procedures and techniques for handling specimens which meet the following characteristics are presented in annex A.
a) Fluorescence of the specimen (from dyes or fluorescent whitening agents [FWAs]) will influence the results depending on the amount of fluorescing material present and the amount and quality of ultraviolet and visible energy in the instrument light source. Results may be particularly hard to duplicate between instruments that do not have methods for calibrating the UV content. Example materials are white or lightly coloured materials treated with FWAs.
b) Moisture content of textile materials can affect their colour and appearance characteristics. The amount of conditioning time necessary to achieve a stable moisture state varies with fibre, fabric construction, dyes and surrounding conditions. Examples of materials the colour of which are typically affected by moisture content are cotton and viscose materials.
c) Non-rigid specimens tend to protrude (or “pillow”) into the viewing port of instruments. The amount of intrusion may vary depending on number of layers, softness of material and the backing pressure applied to mount the specimen. Variations in the amount of intrusion will result in significant deviations in the resulting colour measurement which are non-reproducible. Examples of these materials are fibre, yarn, knits, and layers of lightweight fabric.
d) Non-opaque specimens allow some light to pass through the material during measurement. Most textile materials, by nature of their structure, fit this category. During measurement, any light which passes through the material to reach the backing plate (or escape from the instrument) will yield false results. Examples of these materials are knits, lightweight materials and fiber.
e) Sensitivity of the specimen to light (photochromism) and/or heat(thermochromism) results in nonreproducible results, depending on the degree of sensitivity and the amount of time the specimen is exposed to undesirable conditions. The photochromic properties of a specimen may be determined according to ISO 105-B05:1993.