Dyes
High quality direct dye direct Blue 201
Product Characteristics
Direct Blue 201 is a high-performance direct dye. Its main features include:
Excellent Light Fastness: Belonging to the "Direct Fast" series, its light fastness is significantly superior to ordinary direct dyes.
Strength Specifications: Common strength specifications are 100% and 200%.
Good Solubility: Direct Blue 201 is suitable for various dyeing processes.
Environmental Compliance: Products from major manufacturers can meet the requirements of ecological textile standards.
Application Range
Direct Blue 201 is widely used in the following fields:
Textile Printing & Dyeing: Dyeing and printing of cotton, viscose, silk, and nylon fabrics.
Paper Dyeing: Coloring of cultural paper, packaging paper, and specialty paper.
Leather Dyeing: Dyeing treatment of various leather products.
Other Fields: Coloring of wood, wool, fertilizers, seeds, firecracker paper, wickerwork, etc.
Basic Dye Characteristics
Appearance: Dark blue powder.
Solubility: Direct Blue BRL is soluble in water. It is recommended to dissolve it in hot water at 80-90°C .
Light Fastness: Direct Blue BRL can achieve up to Grade 6 light fastness on cellulosic fibers.
Dyeing pH: Neutral or weakly alkaline conditions are recommended (pH 7-9).
Textile Dyeing Method
1. Direct Blue 201 Dyeing Process Flow
Basic Process: Dye Dissolution → Fabric Immersion → Temperature Rise Dyeing → Fixation Treatment → Washing & Drying
Specific Operation Steps:
Step 1: Dye Dissolution
Use hot soft water at 80-90°C to mix and dissolve the dye.
You can first make a paste with a small amount of wetting agent, then add hot water to dissolve completely.
After dissolution, it must be filtered before adding to the dyeing machine to prevent insoluble particles from affecting the dyeing result.
Step 2: Fabric Pretreatment
Before dyeing, run the fabric in the machine with hot water at around 80°C (without adding any chemicals) for 2 cycles. This is called "heat preservation".
Step 3: Dyeing
Control the dyeing temperature between 80-100°C . The dye has maximum affinity for the fiber in this temperature range.
Dyeing holding time: 30-60 minutes.
Addition method: First add 3/5 of the total dye amount, then after one cycle, add the remaining 2/5.
Step 4: Salt Addition for Exhaustion
Common salt (or Glauber's salt) must be added in portions, typically at the end of the 3rd and 4th cycles.
Step 5: Fixation Treatment
Post-dyeing fixation treatment can significantly improve color fastness.
Treat with Fixing Agent Y. Washing fastness can be improved from Grade 2 to Grade 3-4.
Step 6: After-treatment
After dyeing, wash thoroughly with moderate water flow.
When drying, start with a low cylinder temperature and gradually increase.
Dyeing Precautions
Add Salt in Portions: When dyeing with Direct Blue BRL, salt should be added in portions to control exhaustion and achieve uniform color.
Be Cautious of Metal Ions: The color shade may change slightly when in contact with copper or iron ions. Avoid contact with metal utensils.
Leveling Properties: Direct Blue BRL has relatively poor migrating and leveling properties, so process control is necessary.
Effect of Resin Finishing: The color shade may turn slightly greener after fixation treatment or resin finishing.
Paper Dyeing Method
Direct Blue 201 is also widely used for paper coloring:
Dissolution: Fully dissolve the dye using hot water at 80-90°C.
Addition: Add during the pulp beating or mixing stage.
Dosage: Adjust according to the target color depth. It is recommended to start with a small amount for trial dyeing.
Note: Liquid dye forms are easier to add and use directly.
Leather Dyeing Method
Dissolution: Dissolve thoroughly in hot water, then filter.
Dyeing Conditions: Carry out in a weakly acidic or neutral bath.
Process: Direct Blue 201 can be used in combination with other direct or acid dyes for color matching.
Common Problems and Solutions
Problem Possible Cause Solution
Uneven dyeing / Color patches Salt added too quickly or not in portions. Add salt in portions and extend the leveling time.
Color shade turns greenish Influence of fixing agent or resin finishing. Adjust the fixation process and confirm with a lab dip.
Poor washing fastness No fixation treatment performed. Add a treatment step with Fixing Agent Y.
Color shade change Contact with copper or iron ions. Use stainless steel equipment and soften the water.
Safety and Storage
Storage Conditions: Store in a dry, sealed place, away from moisture.
Packing Specifications: 25 kg/woven bag or cardboard drum.
Safety Note: Industrial product. Avoid inhaling dust. Wear protective equipment during operation.
Usage Recommendations
Sample Before Batch Production: Always conduct a lab dip test before bulk production to confirm that the color shade and strength meet requirements.
Fixation Treatment: If high washing fastness is required, post-dyeing fixation treatment is mandatory.
Process Recording: It is recommended to keep detailed records of the temperature, time, and auxiliary for each dyeing batch to facilitate process optimization and problem tracing.