Textile test methods — Colourfastness and dimensional changes in commercial laundering

This method determines the dimensional change and colourfastness of textile fabrics or garments, likely to occur in commercial laundering procedures. The fabric specimen or garment is subjected to an appropriate combination of specified washing, drying and restoration procedure.

Five washing, five drying and three restoration procedures are included as follows:

Washing Procedures

1 – High temperature (70°C), with bleach

2 – High temperature (60°C), without bleach

3 – Medium temperature (50°C)

4 – Medium temperature (50°C), sensitive fabrics

5 – Low temperature (40°C), sensitive fabrics.

Drying procedures

1. Drip dry
2. Flat-bed press
3. Flat dry
4. Line dry
5. Tumble dry.
    

Restoration Procedures

I – Tension presser

II – Knit shrinkage gauge

III –Hand iron.

Before using this method, the combination of procedures suitable for the particular item to be tested must be selected to arrive at the appropriate test. A complete test consists of a washing, drying and, if necessary, a restoration procedure. For example, Test 3EI means that the textile material has been washed at 50°C with normal mechanical action, and detergent and alkali, dried by tumble drying and restored by tension pressing. The final result obtained will, of course, depend upon the choice of test conditions used.

The five washing tests specified vary in severity of operating conditions and correspond in their essentials to procedures commonly used in commercial laundering. The five drying procedures specified provide appropriate methods for drying different textile materials. Three procedures are specified for determining the dimensional restorability of materials after washing and drying for those textiles that may be restored by ironing or wearing.

This method is suitable for use with woven or knitted fabrics and also with garments and other made-up textile articles. This method is also applicable to certain nonwoven fabrics. For nonwovens, the principal directions of measurement shall be machine direction and cross direction (perpendicular to the machine direction). Nonwoven fabrics are not usually subjected to restoration procedures. This method may not be suitable for use with certain types of fabrics such as those of open construction or delicate nature. Mechanical action is the factor most responsible for fabric distortion during washing and this must be considered when choosing the procedure to be used. Where the amount of mechanical action is required to be minimal (e.g., as in hand washing), CAN/CGSB-4.2 No. 25.1 should be used for dimensional change and CAN/CGSB-4.2 No. 19.1 Test No. 1, for colourfastness.