Why an acid dye can level on wool but produce streaks on nylon

Why does the dye level on wool but streak on nylon?

Fiber type and pretreatment change adsorption sites and uptake. Approval on a different substrate cannot qualify the dye for the present fabric.

Compare positions on the fiber lot and the heating curve

Sample different positions from the same nylon lot and take specimens at intervals under matched liquor ratio and pH. Compare fiber lot, heating profile and early uptake to separate dye and substrate effects.

Why do two lots of the same shade give different depths?

Verify the standard, relative strength, bath pH and target depth before adjusting the recipe. Wool dyeing: Use the same wool sample to compare levelness, shade depth and staining after washing. Nylon dyeing: Trial the target fiber and blend ratio. Observe barré and dye compatibility in combination shades.

Checking Relative strength and Color difference

Relative strength (%): Use a common fibre and commercial reference sample. Color difference (ΔE): Specify depth of shade, illuminant and reference sample. Wet fastness (Grade): Define the test and adjacent material.

What to record

• Fiber lot
• Fabric position
• Starting pH
• Heating profile
• Streak location

Technical references

• Jacquard Acid Dye: compatible fibers ↗

Products and processes