Recommendation for Efficient Enzyme Desizing

What is enzymatic desizing and what are the recommendation for efficient enzyme desizing

Desizing is the process of removing the size material from the warp yarns after the textile fabric is woven.

Enzymatic desizing is a traditional desizing procedure of degrading starch size on cotton fabrics using enzymes. Enzymes are multipart organic, soluble bio-catalysts, created by living organisms that catalyze chemical effect in biological process. Enzymes are quite specific in their act on a particular material. A small amount of enzyme is able to decompose a large quantity of the material.

Recommendation for efficient enzyme desizing

(Ref: BTRA – Bombay textile Research association)

  • Before enzyme de sizing cloth should be wetted with warm water.
  • Enzyme activity should be tested before use.
  • pH should be controlled.
  • Avoid copper made machines.
  • Enzyme treated cloth keep in a rider room.
  • Treated cloth wash with hot water.
  • Should be careful that enzyme above 70 degree centigrade temperature will be inactivate or damage.
Recommendation for Efficient Enzyme Desizing

Recommendation for Efficient Enzyme Desizing

 How enzyme activity depends on concentrate pH and temperature

  • Activity of enzyme increase with the increase of temp but up to certain limit then above that limitation activity decrease.
  • Enzyme stability decrease with increase of temperature.
  • Enzyme activity decrease with longer time.
  • Changing of pH rapidly changes enzyme activity and stability.
  • If concentration of enzyme increase then activity decrease.

Written by

Engineer Sheikh Nurja

B.Sc engineer of textile

Merchandiser at buying house

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Rot steeping Acid steeping Enzyme steeping

Steeping is the soaking in liquid (usually water) of a solid so as to extract flavors or to soften it. Some teas are prepared for drinking by steeping the leaves in heated water to release the flavor and nutrients.

Ideas of Rot steeping acid steeping enzyme steeping

Rot steeping

Rot steeping is the oldest & cheapest way of desizing where no special chemical is used. In rot steeping cloth is passed through warm water of forty degree for this cloth is squeezed up to 100% expression. Although this method is the cheapest but the main disadvantage of this process is it is very much time consuming because it cannot be said that with allocated time sizing material will remove.

Rot steeping acid steeping enzyme steeping

Rot Steeping

Acid steeping

Acid steeping is one of the most useful desizing process where dilute Sulphuric acid is used to Hydrolyze or soften starch. By this method almost all the starch present in the fabric can be liquefied. Fabrics are impregnated with acid solution in a room where the temperature is 30 degree and have to keep it for eight to twelve hours for acid steeping. Remember that during storage of fabric in the tempered room fabric should not be dried otherwise it may damage the fabric.

Enzyme Steeping

The safest method of desizing is enzyme steeping. There is no problem of hydrocellulose which ensure good desizing. This process occupies less space but it is more costly than other desizing methods.

Difference among rot steeping, acid steeping and enzyme steeping

Rot steeping

Acid steeping

Enzyme steeping

De-sizing agent warm water De-sizing agent more dilutes mineral acid De-sizing agent Enzyme
Time 24 hours Time 8-12hours Time 3-4 hour per minute
Hydro-cellulose may from Hydro-cellulose may form No problem of hydro-cellulose
Less wt loss More wt loss Less wt loss
De-sizing process is good De-sizing is better De-sizing is good
More space is required Less space is required Less space is required
Less cost process More cost process More cost process

Written by

Engineer Sheikh Nurja

B.Sc engineer of textile

Merchandiser at buying house

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Classification and Objects of Scouring

Classification and Objects of Scouring

Scouring

Desized textile materials till contain oil, fats and waxes which are removed by alkali or detergent is called scouring.

Classification and Objects of ScouringObjects of scouring/Objectives of Scouring

  1. To remove natural and added oils, fat and wax’s from the textile materials.
  2. Improve hydrophylicity.
  3. Improve absorbency.
  4. Prepare for the next process.
  5. To get uniform bleaching result.

Flow chart of scouring

Flow chart of scouring

Flow Chart of Scouring

Scouring Process

There are two types of scouring process-

  • Hand Scouring
  • Machine Scouring

Hand Scouring

In this process fabric is boiled in an open trough with NaOH common soda and t.r oil for after a few hours. But be careful so that fabric does not come in contact with air otherwise fabric strength can be reduced. After that wash with cold water sour with dilute HCl to remove alkali from the fabric.

Machine Scouring

Now a day’s various types of machines are available for scouring with alkali. This alkali treatment can be divided into three categories.

  • Lime acid soda process.
  • Caustic soda process.
  • Soap soda process.

Written by

Engineer Sheikh Nurja

B.Sc engineer of textile

Merchandiser at buying house

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Enzyme Desizing

Enzyme Desizing

Enzymatic desizing is a traditional desizing procedure of degrading starch size on cotton fabrics using enzymes. Enzymes are multipart organic, soluble bio-catalysts, created by living organisms that catalyze chemical effect in biological process. Enzymes are quite specific in their act on a particular material. A small amount of enzyme is able to decompose a large quantity of the material.

enzyme desizing

Why enzyme desizing is popular?

  • No hydro-cellulose is formed, fabric strength remain changed.
  • The process is continuous and speedy.
  • The desizing capacity is more.
  • Less floor space is required.
  • Weight loss of fabric is less.

Description of continuous enzyme desizing process:

Normally when malt extract is used as the designing agent it takes about 3-4 hours for complete desizing to occur, but when stronger solutions of the extract are used to reduce the time within 5 minute.

continuous enzyme desizing process

Continuous Enzyme Desizing Process

In this case impregnated fabric has to put in the required pit the length of the floor of the pit should be equal to delivered impregnated cloth in 5 minute, so enzyme impregnated cloth, pit and washing machine should be synchronized with each other.

Written by

Engineer Sheikh Nurja

B.Sc engineer of textile

Merchandiser at buying house

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Classification of Desizing

Classification of Desizing

Desizing

Desizing is the first chemical process in wet process. Desizing is the term usually restricted to the process of removal of starch (of the size) from the cloth. De-sizing processes can be controlled by desizing process can be controlled by desizing liquor shorter time process. There are several methods for desizing and these can be classified as follows-

classification of desizing

Classification of Desizing

Objectives of Desizing

From the definition of de-sizing you know that it is a chemical process in wet processing. For this importance there is several objectives of desizing that can be identified. These are:

  • To remove starch from fabric desizing is done.
  • To improve absorbing capacity of the fabric.
  • To make ready for the next process scouring, bleaching etc.
  • To improve absorbing attain of chemicals.
  • Increase luster of dyeing and printing.

Written by

Engineer Sheikh Nurja

B.Sc engineer of textile

Merchandiser at buying house

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Gas Singeing

Description of Gas singeing

As I mentioned earlier to write about gas singeing today I am going to discuss about Gas singeing method and also going to share a comparison study of Plate singeing, Roller singeing and gas singeing

Gas Singeing Machine

This machine consists of one or more burners giving continuous flat or vertical flames, produced by mixture of compressed air and gas. When fabric passes over the flame and singeing is done as require.

gas singeing

Gas Singeing Process Sketch

There are various types of machines depending on burns design. The speed of machines 72-90 m/min depending on cloth varieties. The machines are attached with water tank to save the fabric from any damage. Now a day’s various improved have been done in the machine design. Improper singeing may be lead to as much as 75% tensile strength loss in the warp directions.

Why gas singeing method is popular than other methods?

  1. Better singeing and projecting fibers of interstices is burned by the processes.
  2. Uniform singeing can be maintained.
  3. Smoothness and evenness of the fabric is increased.
  4. Groove is produced in other singeing machines but gas singeing machines is saving from that problem.
  5. Gas flame can be changed according to fabric with.
  6. Production is height than other machines.
  7. Both side of the fabric can be singeing.

Due to the above facilities this gas machine more popular than other machines.

Difference among Plate singeing, Roller singeing and Gas singeing

Plate singeing

Roller singeing Gas singeing
Inter stitches fibres not burned. Same as plate. Inter stitches fibres are burn out.
Due to mental plate friction surface become smooth and luster. Same as plate singeing. Extra luster is not produced.
Fabric moves plate stationary. Both move opposite direction.  Fabric moves only.
Even temperature maintaining is problem. Better than plate singeing. Burning is used.
Metal plate is used. Metal roller is used. Gas flame is used.
Speed:150-250 yards/min. Less than plate singeing. Speed250-400 yards/min.
One side is signed. One side is signed. Both sides are signed.

Written by

Engineer Sheikh Nurja

B.Sc engineer of textile

Merchandiser at buying house

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Classification of Singeing

Singeing

Singing is a process of burn out the projecting fibre to increase smoothness and evenness of the fabric.

Objective of Singeing

  1. Burning of projecting fibres from yarn/fabric surface.
  2. Fabric/Yarn surface become smooth, even and clean.
  3. Maximum Luster is produced by mercerizing.
  4. Help to create smart design by printing.
  5. Save from uneven dyeing & printing.

Classification of Singeing

There are three types of singeing. They are

classification of singeing

Classification of Singeing

Plate Singeing

In plate singeing open fabric is passed upon the copper plate. To maintain ever speed some guide roller and draw roller are used. The temperature of singeing plates are heating but problem is the plate temperature vary. The process speed vary 135-225 m/min.

plate singeing

Plate Singeing

Advantages of plate singeing

Due to friction between cloth surface and copper plate fabric surface become smooth.

Disadvantages of plate singeing

Copper plate not to be evenly so uneven singeing is performed.

Roller Singeing

  • Some defects of plate singeing machine are overcome in roller singeing machine.
  • In roller singeing machine there is used rotating cylinder instead of stationary curved plate as plate singeing machine. It may be made of either copper or cast iron and provided with internal firing system.
roller singeing

Roller Singeing

  • In this machine the surface temperature of the cylinder is more uniform at all places.
  • The rotation of the cylinder is opposite to the fabric movement, so raise the nap ensuring efficient singeing.

Gas Singeing :( Will discuss in my next article as it is so important types. Stay with us.)

By

Engineer Sheikh Nurja

B.Sc engineer of textile

Merchandiser at buying house

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What is Pigments

What is Pigments?

Pigments are such colorants which composed of particles that are insoluble in the application medium. They have no substantivity for the material since the particles are too large to penetrate into the substrate. They are generally present on the surface of the substrate. That’s why pigments are made fixed with an adhesive to the surface so that they are not being removed easily.

What is pigments

Pigment Dyed Fabric

A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.

Required Properties of pigments

  1. Pigments should be opaque in such a way that they may have good covering power.
  2. Pigments should be chemically insert so that after use remain stable and get long life.
  3. They should have the properly to freely mix.

General Classification of Pigments

Natural or mineral pigments:

These are pigments such as

  • Iron
  • Ores
  • Clays
  • Chalk etc.

Chemical or synthetic pigments:

These mainly include

  • Zinc oxide
  • White lead
  • Titanium dioxide
  • Larger number of inorganic and organic colors

Reactive pigments:

Some pigments on account of their chemical character react with oil, fatty acid and soaps, e.g

  • Zinc oxide
  • Red lead

Inert pigment: As for example titanium dioxide

 Classification of Pigments as textile use

Pigments are used in textile may be broadly classify as

  1. Azoic pigments
  2. Vat pigments
  3. Miscellaneous pigments

Of all the Azoic pigments are occurring major places in pigments.

 Advantages of pigment dyeing and printing

  • No wet treatment so it is so simple to do dry and curing
  • It is applicable to all fibres
  • Extensive color range with high light fastness

 Disadvantages of pigment dyeing and printing

  • It has adverse effect due to binders
  • Chemical and physical properties of binders influence in dyeing and printing
  • Using of solvent like kerosene, Spirit etc. produce problem of flammability, pollution etc.
  • It covers high cost.

By

Engineer Sheikh Nurja

B.Sc engineer of textile

Merchandiser at buying house

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Classification of Dyes

Before discussing about the classification of dyes lets have some idea of dyes and what can be the basic characteristics of dyes.

Dyes

A dye is a such type of colorant substance which is capable of imparting it’s color to a given substance, by being soluble in the application medium (usually water) at some points during the coloration process.

classification of dyes

Direct Dyes

In most textile dyeing process, the process initially involves transfer of the colored chemical from the aqueous solution onto the fiber surface which called adsorption process. From there the dye slowly diffuses into the fibre. Depending on internal structure of the fibre, this occurs down pores, or between fibre polymer molecules. The overall process of adsorption and penetration of the dye into the fibre is called absorption. Absorption is a reversible process. The dye can therefore return to the aqueous medium from the dyed material during washing which is called desorption.

Major characteristics of dyes

  • Intense color.
  • Solubility in water at some point during the dyeing cycle.
  • Some substantivity for the fibre being dyed.
  • Reasonable fastness properties of the dyeing produced.
dyed finished fabric

Dyed Finished Fabric

Classification of dyes (according to textile usage)

  • Acid dyes
  • Azoic dyes
  • Basic dyes
  • Direct dyes
  • Disperse dyes
  • Mordant dyes
  • Pigments
  • Reactive dyes
  • Sulpher dyes
  • Vat dyes

By

Engineer Sheikh Nurja

B.Sc engineer of textile

Merchandiser at buying house

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Flow Chart of Wet Processing of Woven Fabrics

What can be the flow chart of wet processing of woven fabrics?

Wet processing is related with the manufactured gathering of fibers, filaments and for yarns. It is a process involved with the aqueous stage of pretreatment, dyeing, printing and finishing.

Wet Processing:

In a broader sense wet processing is the process of inspection of grey fabric, stitching, singeing, resizing, scouring, bleaching, sample testing, mercerizing, souring, washing, sample testing, dying, after treatment, printing, finishing, quality test of sample, assure quality, inspection, rolling, packing and finally deliver to buyer.

Wet processing is very important process of fabric. It is a Textile engineering department. Wet processing engineering is one of the major streams in textile engineering refers to textile chemical processing engineering and applied science.There a lot of factory just for wet processing call dying industry/mill.

wet processing

Here I am presenting flow chart of wet processing for woven fabric.

Flow chart of wet processing

Flow Chart of Wet Processing of Woven Fabrics

  • Sample tests after bleaching: pH, Absorbency, whiteness, Tegwa
  • Sample test after Mercerizing: pH, Absorbency

Quality test after finishing: all quality test according to buyer requirement and keep all quality of their want.

Written by

A.M. Amirul Islam (Washim)
E-mail: [email protected]
Cell : +8801929643301