AATCC standards to determine the colorfastness of nylon fibers

To determine the colorfastness of nylon fibers and fabrics, the American Association of Textile Chemists and Colorists (AATCC) has several standardized testing protocols. Because nylon is a synthetic fiber typically dyed with acid or pre-metalized dyes, these tests evaluate how well the dye bonds under environmental stresses like laundering, friction, light, and perspiration.

The primary AATCC standards used for nylon colorfastness include:

1. Colorfastness to laundering: Accelerated

Standard: AATCC Test Method 61

• Purpose: This standard evaluates the color change and surface changes of textiles resulting from accelerated home or commercial laundering. It designs a single 45-minute test cycle (such as Test 2A) to approximate the destructive detergent, temperature, and mechanical action of multiple home washes.
• Application to Nylon: Nylon samples are paired with a multi-fiber test fabric strip (which includes a nylon band) to check for cross-staining. This is critical for nylon, as improperly fixed acid dyes can bleed onto adjacent fabrics during washing.

2. Colorfastness to Crocking (Rubbing)

Standard: AATCC Test Method 8 (Crockmeter Method)

• Purpose: This test method determines the amount of color transferred from the surface of colored textiles to other surfaces by dry or wet rubbing.
• Application to Nylon: Because deep-shade nylon (such as activewear or dark performance apparel) can suffer from surface dye accumulation, both dry and wet crocking tests are essential. A standard white test cloth is rubbed against the nylon specimen under controlled pressure (9 N), and the transferred color is graded.

3. Colorfastness to Light

Standard: AATCC Test Method 16.3 (Xenon-Arc Lamp Exposure)

• Purpose: Measures the resistance of textile color to fading when exposed to controlled artificial light simulating natural sunlight.
• Application to Nylon: Synthetic fibers like nylon are susceptible to photo-oxidation and UV degradation, which can lead to significant shade change or yellowing. Xenon-arc testing is widely used for outdoor, automotive, and sportswear nylon applications.

4. Colorfastness to Perspiration

Standard: AATCC Test Method 15

• Purpose: Determines the resistance of dyed or printed fabrics to color changes and bleeding when exposed to simulated acid perspiration.
• Application to Nylon: Highly relevant for nylon used in activewear, swimwear, and intimate apparel. The specimen is soaked in an artificial perspiration solution, placed under a specified mechanical load in a test incubator, and later evaluated for shade alteration and staining on multi-fiber strips.

Evaluation and grading

Results across all these tests are universally graded using AATCC evaluation procedures:

• Gray scale for color change: Rates the degree of fading or color alteration on a scale from 5 (negligible or no change) to 1 (severe change).

Gray scale for staining/chromatic transference scale: Rates the amount of dye transferred onto adjacent fibers (such as the nylon or cotton portions of a multi-fiber strip) from 5 (no staining) to 1 (heavy staining).