Difference between Dye Affinity & Dye Substantivity

 

Difference between Dye Affinity & Dye Substantivity

Dye Substantivity	Dye Affinity
Natural attraction between dye molecule and fibre is called dye substantivity.	Attraction between dyes and fibres with dyeing conditions is called dye affinity.
The dye molecules transfer from dye bath to textile materials without any dyeing conditions.	The dye molecules transfer from dye bath to textile materials in presence of heat or temperature.
Substantivity varies with van der Waals and dispersion force between the dye and fibres molecules	Affinity varies with the temperature

Printing of 100% cotton fabric with pigment dye by screen printing.

 

Name of the Experiment : Printing of 100% cotton fabric with pigment dye by screen printing.

Introduction :

Pigment dyeing is a comparatively recent addition. In the process of pigment dyeing, no actual chemical reaction takes place between the dye and the fabric. Instead, what happens is that the pigments get seated on the fabric with the help of binders. The printing of textile material is the application of color according to a predetermined design. In direct style, the dyes are directly printed at the required places of the fabric. Nowadays screen printing is by far the most common technology today. There are two types of screen printing system.

1. Rotary screen printing.

2. Flat screen printing.

Objective :

Ø  To learn about printing process of cotton fabric by pigment.

Ø  To print cotton fabric by pigment.

Ø  To make a combined shade using red, yellow, blue color substances.

Ø  To write a report according to the experiment.

Nature of the sample : 

•      Pre-treated 100% cotton knitted fabric.

Apparatus Required :

•   Beakers.
•   Glass Rod.
•   Pipette.
•   Measuring Cylinder.
•   Digital Balance.
•   Screen.
•   Squeezer.
•   Curing machine.

Process Sequence :

Fabric Preparation

↓

Preparation of Print Paste

↓

Application of Print paste on the surface of the fabric.

↓

Drying the printed fabric for 2-3min

↓

Curing the sample at 150°C

Printing Recipe:

           

            Pigment Red               : 1 parts

            Pigment Yellow           : 2 parts

            Pigment blue               : 4 parts

            binder                          : 2 parts

            fixer                             : 1 parts

            Thickener                    : 70 parts

            Water                          : 23 parts

            Total                            : 100 Parts

Function of Chemicals :

            Fixer:  

Ø  It helps the pigment particle to attach with fabric.

            Binder:

Ø  Binder is the material that holds the pigment together and gives a finish that sticks well to the surface.

            Pigment: 

Ø  Main substances to produce color.

Sample Attachment & Observation :

 

Figure: 5.2

Comments :  Pigments particles attached to the fabric.

Pigment Dyeing of 100% cotton fabric to produce combined shade.

 

Name of the Experiment : Pigment Dyeing of 100% cotton fabric to produce combined shade.

Introduction :

Pigment dyeing is a comparatively recent addition. In the process of pigment dyeing no actual chemical reaction takes place between the dye and the fabric. Instead, what happens is that the pigments get seated on the fabric with the help of binders. There is a challenge in pigment dyeing. Pigments are not soluble in water and show no affinity for fiber. So, conventional dyestuff-based dyeing conditions are not feasible for pigment dyeing. To come to terms with such limitations, a new kind of pigments have been formulated for use in fibers. These are maintained in a stable dispersion in the medium of water by anionic surfactants. This type of pigment is known as pigment resin color (PRC), primarily used in printing. Some of the popular pigments used in fabrics

Objective :

Ø  To learn about dyeing process of cotton fabric by pigment.

Ø  To dye cotton fabric by pigment.

Ø  To make a combined shade using red, yellow, blue color substances.

Ø  To write a report according to the experiment.

Nature of the sample : 

•      Pre-treated 100% cotton knitted fabric.

Apparatus Required :

•      Beakers.
•      Glass Rod.
•      Pipette.
•      Measuring Cylinder.
•      Digital Balance.
•     Tri-pod stand.
•      Gas Burner.
•     Thermometer.
•      Pot.
•      Padding Mangle machine.

Process Sequence :

Collection of pre-treated sample

↓

Set water level

↓

Add Pigment solution

↓

Add binder solution

↓

Add fixer solution

↓

Add fabric sample

↓

Raise the temperature to 60deg C

↓

Run time for 20 minute

↓

Bath drop

↓

Padding

↓

Curing

↓

Wash

Dyeing Recipe has been shown in table: 5.1

SL	Process Parameter	Unit	Dossing	Stock Solution
01	Binder	g/L	1	1%
02	Fixer	g/L	2	1%
03	Pigment Red	%	0.5	1%
04	Pigment Yellow	%	1	1%
05	Pigment Blue	%	0.5	1%
06	Sample Weight	gm	5	---
07	M:L	-----	1:30	---
08	Temperature	°C	60	---
09	Time	min	20	----

Function of Chemicals :

            Fixer:  

Ø  It helps the pigment particle to attach with fabric.

            Binder:

Ø  Binder is the material that holds the pigment together and gives a finish that sticks well to the surface.

            Pigment: 

Ø  Main substances to produce color.

Calculation :

            Total Liquor:              Material Weight X L        { M:L }

                                                = 5gm X 30

                                                = 150 mL

`           Binder :                      =  (150 X 1)/(1% X 1000) mL   

                                                =  15mL

            Fixer:                           =(150 X 2)/(1% X 1000)   mL  

                                             =   30mL         

            Pigment Red:             =(5 X 0.5%)/(1%)  mL  

                                                =  2.5 mL

            Pigment Yellow:      =(5 X 1%)/(1%)  mL 

                                                =  5 mL

                Pigment Blue:           =(5 X 0.5%)/(1%)  mL

                                                =  2.5 mL

            Initial Water :                         = Total Liquor - (chemicals)

                                                = 150 - (15+30+2.5+5+2.5)mL

                                                = 95mL

Process Curve :

Figure 5.1 : Process Curve

Sample Attachment & Observation :

Figure: 5.2

Comments :  Pigments particles attached on the fabric surface.

Determination of color fastness to washing using a gray scale.

 

Name of the Experiments: Determination of color fastness to washing using a gray scale.

1. Objective:

To learn about color fastness to washing.

To learn about the process to test color fastness to washing.

2. Theory:

Color fastness to washing means, A specimen of the textile, in contact with one or two specified adjacent fabrics, is mechanically agitated under described conditions of time and temperature in a soap solution, then rinsed and dried. The change in color of the specimen and the staining of the adjacent fabric are assessed with the grey scales.

3. Experimental Procedure:

Sample: Natural dyed sample of 10X4 cm².

Dyes & Chemicals:

Table 7.1: List of dyes and chemicals

Dyes & Chemicals	Function
Detergent	To remove dirt, dust & excessive color.
Sodium Perborate	It available as an active oxidant in detergent.

Equipment List:

o   Beaker.

o   Measuring Cylinder.

o   Pipette.

o   Pot.

o   Digital Balance.

o   Scissor.

o   Tri-pod stand.

o   Gas Burner.

o   Thermometer.

o   Gray scale for color change.

o   Gray scale for color fading.

o   Light Box.

o   Dryer.

o   Multi fibre.

4.Working Procedure:

Table 7.2 :  Recipe of Washing

SL	Process Parameter	Unit	Dossing	Stock Solution
01	Detergent	g/L	4	1%
02	Sodium Perborate	g/L	1	1%
03	M:L	------	1:50	------
04	Temperature	°C	40	------
05	Time	min	30	-------

Calculation:

                Total Liquor:                       50mL

                                                               

               

                Detergent :                         =  (50 X 4)/(1% X 1000) mL  

                                                                =  20mL

                Sodium Perborate :         =  (50 X 1)/(1% X 1000) mL  

                                                                =  5mL

                           Initial Water :                     = Total Liquor - (chemicals)

                                                                = 50 - (20+5)mL

                                                                = 50-25 mL

                                                                = 25mL

Process Flow Chart:

Sample & Multi-fibre conditioned as lab standard (20±2)°C temperature and relative humidity (65±2).

↓

Take multi-fibre & sample of 10X4 cm².

↓

Sewing both multi-fibre and test specimen together.

↓

Wash sewed specimen as per recipe.

↓

Final assessment with both type of gray scale.  

Figure 7.1: Process Flow Chart

Process Description:

                At first, we need to collect conditioned dyed sample and multi-fiber of 10X4 cm² and stitch them together. Then we need to set bath and take chemicals as per recipe. Then we immersed sample to the bath and heated it up to 40°C for 30 minutes. After the process, it need to dry the sample and compare with grayscale to color change for dyed sample and compare with grayscale to color staining for multi-fiber.

Precautions:

o   Taking chemicals as per recipe provided by the Instructor.

o   Taking every weight of chemicals carefully.

5. Result & Discussion:                                 

Discussion: We have to compare our sample with gray scale of color change & compare our multi-fibre with gray scale of color staining.

Rating for color change: 2-3

Table 7.3: Rating for staining (Multi-fibre)

Acetate	Cotton	Nylon	Polyester	Acrylic	Wool
4-5	4-5	3-4	5	5	5

6. Conclusion & Comments: By doing this experiment we have learned about the determination of color fastness to washing of any dyed sample by rating color change and color staining.