ACID DONOR AND PH REGULATOR FOR DYEING POLYAMIDE AND WOOL

AVCO-CID LPH is an acid donor that generates acidity upon heating during the dyeing process. The rate of dissociation is slow in cold solutions, and increases while heating up.This slow dissociation process is useful for dyeing wool and polyamide fibers, as the dyes are exhausted quite evenly and produce levelled dyed yarns and fabrics.

SPECIFICATIONS:

Appearance	Light yellowish clear liquid
Chemical nature	Aliphatic esters
Solubility	Miscible with water. Solutions are not stable and start to hydrolize
Density (g/cc)	1.25 – 1.27
pH (0.1 % in warm sol.)	4.0 – 4.5
Ionic type	Non-ionic
Compatibility	Is not comopatible with strong alkalis. Slowly hydrolyses in water and decompose to an organic acid.
Storage	Stored in a closed container in a cool place. Do not store in direct sun.

PROPERTIES & USES:

1. AVCO-CID LPH is an acid donor which evenly and slowly hydrolizes in hot aqueous solution to produce an organic acid.

2. During the hydrolysis process, the organic acid produced is lowering the pH of the solution down to 4.5-5.5 according to the concentration in the liquor.

3. The rate of the dissociation is slow in cold solutions and increases when the temperature is raised.

4. This manner of pH control makes it useful for dyeing wool and polyamides with acid and metal complex dyes. As the exhaution rate of acid dyes is pH dependent, the slow lowering of the pH in a dyeing solution containing AVCO-CID LPH, ensures more level dyeing, due to slower exhaution rate of the dyestuffs onto the fibres.

5. AVCO-CID LPH is recommended for even dyeing of polyamide, wool and blends of these fibres.

6. AVCO-CID LPH does not influence any of the fastness properties of the dyed fibres.APPLICATION:

It is recommended to adjust the intial pH of the dyeing solution slightly on the alkaline side with ammonia. Initial pH of 7.0 – 8.0 for wool and of 8.0-9.0 for polyamide is recommended. Following are some recommended dyeing procedures. The dosages, temperatures and procedures are suggestions which may vary according to the type of dyestuffs used and properties of fibres to be dyed.

1. Dyeing wool

Use the following recipe:

AVCOLON PAN 0.5 – 2.0 %

Ammonium Sulphate 1.0 – 3.0 g/l

AVCO-CID LPH 0.5 – 1.5 g/l

Dyestuffs X %

Start dyeing at 30°C, raise the temperature to the boil in about 45 min.

Dye at the boil for 60 – 90 min. depending on the depth of the shade.

2. Dyeing wool with an anti-shrink treatment

Use the following recipe:

AVCO-LON PAN 0.5 – 2.0 %

ammonia sol. (25%) 1.0 – 2.0 g/l (adjust to pH 8-9).

AVCO-CID LPH 1.0 – 2.0 g/l

Dyestuffs X %

Start dyeing at 30°C, raise the temperature to 60°C at 1.5°C/min. Hold at 60°C for

10 min. Continue heating at 1°C/min. to the boil. Dye at the boil for 60-90 min.

3. Dyeing polyamide/wool blends

Use the following recipe:

AVCO-LON PAN 0.5 – 2.0 %

AVCO-CID LPH 0.5 – 2.0 g/l

Dyestuffs X %

Start dyeing at 30°C, raise the temperature to 60°C at 1.5° C/min. Hold for 15 min.

Continue heating at 1°C/min. to the boil. Dye at the boil for 60 min.

4. Dyeing polyamide

Use the following recipe:

AVCO-LON PAN 0.5 – 2.0 %

Ammonium sol. (25%) 1.0 – 2.0 g/l (adjust to pH 7-8)

AVCO-CID LPH 0.5 – 1.5 g/l

Dyestuffs X

Start dyeing at 40-50°C, raise the temperature to the boil at 0.5-1.5°C/min. Dye at the boil for 60 min. Cool down to 70°C and drop the bath. Rinse with cold water.

Dosage of AVCO-CID LPH

LIGHT SHADES 0.5 – 1.0 g/l

MEDIUM SHADES 1.0 – 1.5 g/l

DARK SHADES 1.5 – 2.0 g/l