I. Technical Specifications
 
1. Appearance: Light grayish-green pasty liquid
2. Shade: Blue light
3. Fineness: ≥90% of particles ≤2 μm
4. pH Value: 6–7
5. Specific Gravity: 1.035 ± 0.02
6. Ionicity: Non-ionic
 
II. Application
 
Mainly used for whitening and brightening polyester fibers or polyester-blended fabrics.
 
III. Usage Methods
 
1. Low-Temperature Exhaust Dyeing Method
 
- Dosage: 0.2–1.0% (o.w.f) (based on the weight of the fabric)
- Liquor Ratio: 1:10–20 (fabric weight : dye bath volume)
- Dyeing Temperature: 95–100°C
- Dyeing Time: 30–40 minutes
- pH Adjustment: 4.5–5.5 (adjusted with acetic acid)
 
Process Flow:
 
1. Add sodium sulfate and Fluorescent Whitening Agent PS to the dye bath according to the formula.
2. Adjust the bath pH to 4.5–5.5 using acetic acid.
3. Heat the bath to 95–100°C and maintain this temperature for 30–40 minutes (constant-temperature dyeing).
4. Cool down the bath → Rinse the fabric with water → Dehydrate → Dry completely (100% drying) to obtain the finished product, which meets the required whiteness standard.
5. (Optional) If setting equipment is available: After water rinsing, dehydration, and pre-drying, perform curing (170–175°C for 30–40 seconds) to achieve better whiteness.
 
2. Pad Dyeing Method
 
- Dosage: 1.5–4 g/L (per liter of padding liquor)
 
Process Flow:
Two dips and two pads (padding rate: 70%) → Pre-drying (100°C) → Curing & setting (165–175°C for 30 seconds).
 
IV. Precautions
 
1. The whitening agent is a light grayish-green pasty liquid; shake thoroughly before use to ensure uniform consistency.
2. If sedimentation or layering of the paste occurs, simply shake well to restore uniformity—this does not affect the product’s performance.
3. Use the product within its yellowing threshold:
- Maximum dosage for pad dyeing: 5 g/L
- Maximum dosage for exhaust dyeing: 0.8% (o.w.f)
Exceeding these dosages may cause the fabric to yellow.
4. For low-temperature whitening, add 2–6% (o.w.f) of a swelling agent if necessary—this improves whiteness and ensures even color distribution on the fabric.
 
V. Packaging & Storage
 
- Packaging:
- 5 kg plastic buckets;
- 20 kg cartons (containing 4 buckets);
- Custom small-sized packaging available upon request.
- Storage: Store at room temperature. Shelf life: 6–8 months (unopened).