On dyeing Polyester/spandex blends with disperse dyes, reproducibility deteriorates as disperse dyestuff stains heavily on (is adsorbed into) spandex. This kind of dyeing also often involves other trouble such as production of insufficient fastness. By adding Neoleve SDX-D to the dye bath, it potently prevents disperse dye from staining on (being adsorbed into) spandex, and helps its further distribution in polyester. Furthermore, Emill NW-1570 used in Finishing after dyeing further washes off stains, leading to good reproducibility and colorfastness to washing/dry-cleaning (less staining in test liquor).

Standard usage

Disperse dyestuff is adsorbed in spandex up to around 100°C, then as the temperature rises, it begins shifting onto polyester. Higher temperature is preferable, however, with spandex' other physical characteristics taken into consideration, dyeing is normally carried out around 120°C. If the spandex blending rate is so low that its colorfastness can be ignored, soda ash instead of caustic soda (NaOH) is used.

Example n anti-staining agent and soaping agent

Test specimen: Polyester/spandex (operon)

<Anti-staining agent performance test>

Anti-staining properties of Neoleve SDX-D (colorfastness to dry cleaning and washing, residual-liquor absorption) were tested following the method below.

[Test method]

Colorfastness comparison tests

1)	Dry cleaning fastness:	Fabric, after being set, is folded into a small piece, soaked in dry cleaning liquor for 5 minutes and left on filter paper No. 5B until dry.
2)	Washing fastness:	JIS A-2 method (5 g/L marseilles soap, 50°C x 30min) with white silk and polyester pieces attached
3)	Absorption in residual liquor:	nylon jersey added in the residual liquor of the washing fastness test, 80°C x 30 min

[Test data]

1A Anti-staining agent not used in dyeing 2A Neoleve SDX-D 4% (o.w.f.) used in dyeing 3A A competitor's anti-staining agent 4% (o.w.f.) used in dyeing

→

RC conditions are the same in 1A, 2A and 3A. Hydrosulfite 4g/L NaOH (flake) 2g/L Emill NW-1570 2g/L

Colorfastness of 1A, 2A and 3A were examined after being set and performances of anti-staining agents were compared.

1) Dry cleaning fastness:	the less bleeding denotes the better performance.
2) Washing fastness,	washing fastness tested based on JIS A-2 method with white silk and polyester pieces attached. After taking out the pieces, nylon jersey added in the residual liquor, 80°C x 30 min. The paler color denotes the better performance.
3) Absorption in residual liquor:

[Results]

(Click for enlargement)

Reduction cleaning agent performance test

Soaping properties of Emill NW-1570 (colorfastness to washing, absorption in residual-liquor) were tested following the method below.

[Test method]

Tested specimen: Polyester/Spandex (operon)

Colorfastness comparison tests

1)	Washing fastness:	JIS A-2 method (5 g/L marseilles soap, 50°C x 30 min) with white silk and polyester pieces attached.
2)	Absorption in residual liquor:	nylon jersey added in the residual liquor of the washing fastness test, 80°C x 30 min

[Test data]

Dyeing conditions are the same in 1B, 2B and 3B, with no anti-staining agent used.
RC = Hydrosulfite 4 g/L, NaOH (flake) 2 g/L in all cases

1B	No soaping agent used
2B	Emill NW-1570 2 g/L used
3B	A competitor's soaping agent 2 g/L used

[Results]

(Click for enlargement)