ISO standards to determine colorfastness of spandex materials

When it comes to determining the colorfastness of spandex materials, the ISO 105 series of standards is the most globally recognized and comprehensive framework. While there isn't one single ISO standard for spandex colorfastness specifically, various parts of the ISO 105 series are applied to fabrics containing spandex, as spandex is almost always blended with other fibers. These tests assess how well the color holds up to common conditions.

ISO 105 standards used for spandex-containing fabrics

Here are the most relevant ISO 105 standards that testing laboratories use to evaluate the colorfastness of materials containing spandex:

• ISO 105-C06: Colorfastness to Washing
• This standard determines the resistance of textile colors to domestic or commercial laundering procedures. Given spandex's heat sensitivity, controlling washing temperature and detergent type is crucial to prevent color loss or degradation. It assesses both the color change of the test fabric and the staining of adjacent multi-fiber swatch (to check for color transfer).

• ISO 105-X12: Colorfastness to Rubbing (Crocking)
• This standard evaluates how much color transfers from the textile surface to another fabric by rubbing, in both dry and wet conditions. For spandex, which might have surface dyes or residues, this is important to ensure color doesn't rub off onto skin or other garments.

• ISO 105-E04: Colorfastness to Perspiration
• Crucial for activewear, swimwear, and intimate apparel, this standard measures the fabric's ability to retain its color when exposed to simulated human sweat (both acidic and alkaline solutions). Spandex is frequently used in garments where direct skin contact and sweat exposure are common.

• ISO 105-B02: Colorfastness to Artificial Light (Xenon Arc Fading Lamp)
• This standard assesses the resistance of textile colors to fading when exposed to artificial light that simulates natural daylight. While the dye on the other fibers might be the primary factor, the overall appearance of a spandex blend depends on all components resisting light degradation.

• ISO 105-E03: Colorfastness to Chlorinated Water (Swimming-pool Water)
• Specifically vital for swimwear, this standard determines how well the color resists active chlorine in concentrations found in swimming pools. Chlorine can be particularly harsh on dyes and fibers, including spandex.

• ISO 105-E01: Colorfastness to Water
• This test evaluates the resistance of color to immersion in water, which is a more basic test but still important for general textile use.

 Understanding the evaluation

In all these ISO 105 tests, the colorfastness is typically assessed using a Grey Scale:

• ISO 105-A02 (Grey Scale for Assessing Change in Color): Used to evaluate the degree of color change in the tested specimen.
• ISO 105-A03 (Grey Scale for Assessing Staining): Used to evaluate the degree of staining on the adjacent undyed fabrics.

The grading usually ranges from 1 to 5, where 5 indicates excellent colorfastness (no change or staining) and 1 indicates very poor colorfastness (significant change or staining).

When dealing with spandex fibers in blends, textile testing labs pay careful attention to both the color retention of the overall fabric and any potential staining onto other fibers within the blend or adjacent materials. The choice of specific ISO standards will depend on the end-use of the textile product containing spandex.