Application of fluorescent whitening agents on acetate fabrics
Acetate fiber is a thermoplastic fiber that is easily deformed under high temperature and high humidity conditions, affecting its gloss. Therefore, the processing temperature should not be too high. From its chemical structure, it is an ester of cellulose. If a saponification reaction occurs, the characteristics of acetate fiber will be lost and the dyeing performance will also change. Therefore, special attention should be paid when processing in acid and alkali baths. At the same time, due to the poor strength of acetate fiber, the tension should be small during operation to prevent breakage. Acetate fabric must be desized before whitening, and can only be whitened after washing, otherwise the whitening effect will be affected.
Application example 1:
The optical brightener Tinopal ET (C.I. Optical brightener 156) can be used to whiten acetate fibers by three methods: dip dyeing, pad dyeing and hot melting.
(1) Dyeing and whitening.
①Single whitening formula:
Tinopal ET 0. 3% ~ 3% (o. m. f.)
Whitening process:
The fabric is dyed at 40-50°C and treated for 10-15min. Then the dye bath is heated to 85-90°C within 30min, and the dyeing is kept for 30-60min. Take it out, wash and dry.
② Formula for same bath with chlorite bleaching:
Tinopal ET 0. 3% ~ 3% (o. m. f.)
Sodium chlorite (80%) 1 ~ 3g/L
Oxalic acid (adjusted pH = 3 ~ 4) 1 ~ 2g/L
Sodium nitrate 3g/L
Whitening process:
The fabric is dyed at 40°C, then the dye bath is heated to 90°C to 90°C within 20°C to 30°C, kept dyed for 45°C to 60°C, taken out, washed and dried.
(2) Pad dyeing and whitening formula:
Tinopal ET 5～30g/L
Formic acid (85%) 2 ~ 3mL/L
Whitening process:
The fabric is padded with 5-30g/L fluorescent whitening agent (padding rate of about 50%) at 20-40°C without drying in the middle, and then immersed in a 2-3mL/L formic acid (85%) bath. Process in boiling state for 5 to 15 minutes, take out, wash and dry.
(3) Hot melt whitening formula:
Tinopal ET 5～30g/L
Whitening process:
Pad the fabric with 5-30g/L fluorescent whitening agent at 20 to 40 degrees Celsius (the padding rate is about 50%), and treat it for about 18 seconds at 210 to 225 degrees Fahrenheit to obtain a satisfactory whitening effect.
Application Example 2:
Fluorescent brightener DCB (C.I. Fluorescent Whitening Agent 121) can produce excellent whitening effect on acetate fiber, dyeing above 40, and is not affected by pH value. It can be used with improved acetate fiber The surface saponification finishing to improve the hand feel of fiber fabrics and reduce electrostatic induction is performed at the same time or followed by whitening. It can be used for dip dyeing or pad-steaming, and is also suitable for whitening printing ground colors.
(1) Triacetate fiber whitening.
① Dip dyeing formula:
Blankophor DCB Ultrafine or Blankophor DCB Ultrafine R pH (acetic acid adjustment)
Whitening process: process at 80 ~ 125 for 30 minutes.
(2) Diacetate fiber whitening.
① Dip dyeing and whitening formula:
Blankophor DCB Ultrafine or
Blankophor DCB Ultrafine R 0. 2% ~ 1% (o. m. f.)
pH value (acetic acid adjustment) 4
Whitening process:
at 60 ~ 70, process for 30 minutes
Application example 3:
Optical brightener Blankophor ACF (C. I. Optical brightener 101) The exhaust dyeing method can be used to obtain brilliant whitening effects on diacetate fiber and triacetate fiber. The whitening effect will be enhanced when used in chlorite bleach baths. It can be used on almost all common dyeing machines, such as beam dyeing, package high-pressure dyeing and package dyeing machines.
(1) Single whitening formula:
Blankophor ACF 0. 5% ~ 2% (o. m. f.)
Diadavin EWN 0. 5 ~ 1g/L
Acetic acid (60%) 1. 5mL/L
pH value 4～5
Whitening process:
diacetate fiber is treated at 70~80 for 30~45min; triacetate fiber
Process at high temperature of 80 to 115 for 20 minutes.
(2) Bleaching-whitening bath formula:
Blankophor ACF 1% ~ 2% (o. m. f.)
Sodium chlorite (50%) 0. 5 ~ 2g/L
Complex phosphate 0. 3g/L
Avolan IW 0. 3g/L
Formic acid (85%) 1mL/L
Or oxalic acid 0. 5g/L
pH value 3～4
Application example 4:
Fluorescent whitening agent DT dip dyeing whitening. formula:
Yi n g g u a n g z e n g b a i j i s h i y o n g j i s h u
Optical brightener DT 0. 7% (o.m.f.)
Leveling agent OP 0. 5g/L
Whitening process:
liquor ratio 1:30, 50-80, dip dyeing for 25 minutes.
