ISO 105-Z06:1998 download free.Textiles-Tests for colour fastness – Part Z06 : Evaluation of dye and pigment migration.
This part of ISO 105 describes a method for assessing the migration propensity of a pad liquor system containing dyes or pigments. subsequently referred to as colorants, and which may also contain different types and amounts of migration inhibitors. The degree of migration is obtained by visual examination or by reflectance inca sure in en t s.
The test method may be used to compare the migration propensity of dyes and the effect on migration of different types of migration inhibitors, thickeners and electrolyte. The method may also be used to evaluate a pad liquor with which migration has been found on a continuous dye range.
2 Normative reference
The following standard contains provisions which, through reference in this text, constitutes provisions of this part of ISO 105. At the time of publication, the edition indicated was valid. All standards are subject to revision and parties to agreements based on this part of ISO 105 are encouraged to investigate the possibility of applying the most recent edition of the standard listed below. Members of IEC and ISO maintain registers of currently valid International Standards.
ISO I 05—A02: 1993, Textiles – Te,sts for colour fa,srizess – Part A02 Grey scale for assessing change in colour.
3 Definitions
For the purposes of this part of ISO 105, the following definitions apply.
3.1 dye: Colorant applied to or formed on a substrate, via the molecularly dispersed state, which exhibits some degree of permanence.
3.2 migration: Movement of a chemical, dye or pigment between fibres, within a substrate or between substrates due to capillary forces.
NOTL — Migration may occur in textile processing. testing. storage and use.
3.3 pigment: Colorant in particulate form which is insoluble in a substrate, but which can be dispersed in the
substrate to modify its colour.
3.4 pad: Impregnation of a substrate (usually fabric) with a liquor, followed by squeezing between rollers.
Fabric impregnated with test colorant alone, or with test colorant and migration inhibitor, is dried while partially covered with a watch glass, permitting differential drying and therefore, migration to occur. The degree of migration is evaluated by visual examination or by reflectance measurements of the covered and uncovered areas.
NOTES
1 When drying conditions are not constant and/or uniform, uneven migration may occur, causing shade variations during a run, or shade differences between the face and back, or between the side and centre of the fabric.
2 The pad liquor composition may be modified by varying the amount or type of migration inhibitor and tested in the laboratory prior to the application on the range. The colorant concentration, the fabric and the wet pickup should be the same in the laboratory as used on the range. It is then possible to correlate the test results with the improvement experienced in practice.
Two procedures are described:
Procedure A. The fabric assembly is allowed to dry at room temperature. The procedure is very simple, but time- consuming (overnight).
Procedure B. The fabric assembly is dried in a laboratory dryer or oven, either with, or without air circulation. This procedure is faster but somewhat more complicated than procedure A.
5.1 Fabric pieces for dyeing.
NOTE — For disperse dyes, vat dyes and pigments. generally the preferred fabric is a blend of 65 %:35 % (in/rn) polyester:
cotton gabardine or heavy twill, heat set, bleached and mercerized. For soluble dyes with affinity to cellulose (e.g. reactive dyes), the preferred fabric is a bleached and mercerized 100 % Cotton gabardine or heavy twill. However, any oher fabric intended for use on a continuous dye range may be chosen.
5.2 Balance, capable of weighing to an accuracy of I mg.
5.3 Laboratory padder.
5.4 Glass plate, 350 mm x 600 mm. for procedure A.
5.5 Watch glasses, 90 mm diameter with 22 mm arch punch.
5.6 Laboratory pin frame, for procedure B.
5.7 Aluminium rings, 110 mm outer diameter, 80 mm inner diameter, 1 mm thickness, for procedure B.
5.8 Clips, e.g. metal binder clips for procedure B.
5.9 Laboratory dryer or oven, for procedure B.
5.10 Grey scale for assessing change in colour, in accordance with ISO 105-A02.
7 Procedure
WARNING — It is the user’s responsibility to use safe and proper techniques in handling materials in this test method and to follow good laboratory practices. Consult manufacturers for specific details, such as material safeh data sheets and other manufacturers’ recommendations. Users should also comply with any national and local safety regulations.
7.1 Procedure A
Cut a 150 mm x 300 mm piece of fabric (5.1), weigh it using the balance (5.2) and then pad it using the laboratory padder (5.3) at (20 ± 2) °C. If other padding temperatures are used, these shall be stated in the test report. Generally the wet pickup is 60 % by mass, hut may he adjusted to simulate wet pickup of a particular fabric to be run on a particular range. The pad bath contains colorants and usually, auxiliaries.
NOTE — Observe padder safety. Normal safeguards on padders should not he removed. Ensure that there is an adequate guard at the roller nip point. A foot-operated kick-off is recommended.
Obtain the desired wet pickup by adjusting the pressure at the nip of the pad rolls. Calculate the percent wet pickup as the mass gained by the substrate after padding using the following equation:
7.2 Procedure B
Proceed as described in procedure A, using a piece of fabric sufficiently large (usually about 110 mm x 220 mm) to fit a laboratory pin frame (5.6).
Immediately after padding mount the fabric taut on the pin frame (5.6), sandwiched between two watch glasses
(5.5). one on the fabric face and one directly underneath on the back of the fabric. Hold the watch glasses in place
with two aluminium rings (5.7) and clips (5.8) as shown in figure 2. Dry the fabric assembly horizontally at
(100 ± 2) °C for approximately 7 mm (or until dry) in a laboratory dryer or oven (5.9).
Remove the watch glasses and remove the fabric from the pin frame. Determine the degree of migration in accordance with clause 8 by comparing the dye concentration in the area of the fabric which was covered by the watch glasses, to the dye concentration in the area of the fabric which was not covered.