LEVELING AGENT FOR POLYAMIDE AND WOOL

AVCO-LON ESL acts as a leveling agent with the usual classes of dyestuffs used to dye Polyamide and Wool such as Acid and metal-complex dyes. It enhances the migration capacity of the dyes and compensates for any un-levelness caused by the nature of the material. AVCO-LON ESL works through a bi-functional system based on weak saturation of dyeing sites on the fibres, and on the other hand weak bonding of the dyestuff molecules, thus there is an even build up of shade through controlled exhaustion. The result is a level dyeing with good coverage of “barre” and warp streaks.

SPECIFICATIONS:

Appearance	Slightly brown liquid.
Chemical nature	Aqueous compound of poly-ethoxylated fatty amines and sulphonated surfactants.
Ionic type	Non-ionic / anionic
pH (10% sol)	9 – 10
Solubility	Soluble in water at any ratio.
Stability to: Alkalis, Acids, Electrolytes, Water hardness	Good resistance under conditions normally encountered in textile practice.
Storage	Freezes below 0°C but fully usable after thawing and agitating. Stable for at least 12 months.

PROPERTIES & USES:

1. AVCO-LON ESL is an anionic/nonionic leveling agent with moderate affinity to the cationic dye-sites on the polyamide fibres and to the anionic anchors on the acid dyestuff molecules.

2. Excellent leveling properties with good migrating capacity and good dye yield which enables leveled dyeing of polyamide micro-fibres, and other polyamide fibres which have severe affinity differences (“barriness”).

3. Suitable for dyeing acid dyes as well as metal complex dyestuffs.

4. Suitable for dyeing at the boil and at HT conditions..

5. AVCO-LON ESL does not impair the fastness properties of the dyed fibres.

6. Recommended for dyeing all types of polyamide goods such as fibres, yarns, fabrics, and ready-made garments. AVCO-LON ESL is recommended for dyeing blends of polyamide with other fibres such as cellulose and wool.

7. AVCO-LON ESL is a good leveling agent for dyeing polyamide with suitable disperse dyes.

8. AVCO-LON ESL is recommended for dyeing wool fibres, yarns and garments.

APPLICATION:

The exact dosage of AVCO-LON ESL depends on the type of dyestuff used. Acid dyestuffs with “poor leveling” properties and high wet fastness, are dyed at acid pH (5.0 – 6.0) using acetic acid and ammonium sulfate or acid donor (AVCO-CID HTA-200 or AVCO-CID LPH) to control the pH. Such dyestuffs need 2.5-1.5% of AVCO-LON ESL. ( higher amount on light shades)

Acid dyestuffs with “good leveling” properties need slightly acid pH. Such dyestuffs need reduced amounts of AVCO-LON ESL.

Following are guiding quantities for the use of AVCO-LON ESL:

Type of Dyes	% on weight of knits
	Pale Shades	Medium Shades	Dark Shades
Acid Dyes (good migration)	2	1.5	1
Acid Dyes (low migration)	2.5	2	1.5
Metal Complex	1.5	1	0.5

Remark: when dyeing difficult articles with a great tendency to “barriness”, increase dosage of AVCO-LON ESL to 3%.

Dyeing polyamide fabrics

1. Add ammonium sulfate (1 – 3%) or acetic acid (0.5 – 1.5%) or an acid donor(AVCO-CID LPH or AVCO-CID HTA-200) according to dyestuff manufacturer recommendation and run for 5 minutes.

2. Add AVCO-LON ESL and run for 5 minutes.

3. Add well dissolved dyes by linear dosing over 15 minutes.

4. Run for 5 min. and heat-up to the desired temperature: 98-120°C. The heating rate is 1-2 °C /min.

5. Dye for 45-60 min. Check for final exhaustion and the pH.

6. Cool down, drop the bath and rinse.

Remark: Shading additions can be made in most cases at dyeing temperatures.

Dyeing polyamide fabrics with extreme tendency to “barriness”

In this case use the pre-boiling method according to the following procedure:

1. Set bath with 0.5 – 1.5 cc/l acetic acid(60%) or with 1 – 3% ammonium sulfate. Or with an acid donor (AVCO-CID LPH or AVCO-CID HTA-200).

2. Add 3% AVCO-LON ESL.

3. Boil the fabric in the bath for 20 -30 minutes.

4. Add the pre-dissolved dyestuffs without in-between cooling.

5. Dye for 45 – 60 minutes at the boil, or raise up temperature and dye at 120°C.

Remark:

It is recommended to use a dyeing machine type with good circulation of the dyeing liquor and high throughput.

Correcting of unleveled dyeing:

1. Treat at the boil with 3-4 g/l of AVCO-LON ESL for 30 minutes.

2. Cool down.

3. Add acetic acid to the desired pH according to the type of dyestuffs used. The acid should be added slowly by dosing method.

4. Add additional amount of acid dyestuffs if required.

5. Raise the temperature to the boil and treat at the boil for 30 minutes.

6. Cool down, drop the bath and rinse.

Dyeing polyamide with disperse dyes

AVCO-LON ESL has excellent leveling and dispersing effect for dyeing polyamide with suitable disperse dyes. Dosage should be 0.5 – 1 g/l.

Dyeing wool:

AVCO-LON ESL is highly recommended as a leveling agent for wool dyeing, especially with acid and milling dyestuffs. Dosage should be 1 – 2% on the weight of goods.