Showing posts with label Wool. Show all posts
Showing posts with label Wool. Show all posts
15 November 2012
Wool Finishing Processes
Wool Finishing Processes
The sequence of the treatments undergone by wool fibres
in various forms (staple, sliver, yarn, woven and knitted fabric)
varies according to the modification process of the fibre structure,
according to the type of processing system used and according to the
experience of the operator (these criteria are valid for all fibres).
Therefore the wool processing cycle can vary accordingly: an example is shown in the following.
Therefore the wool processing cycle can vary accordingly: an example is shown in the following.
Worsted Cycle:
Flowchart of worsted wool finishing process
Woollen Cycle:
Flowchart of woollen wool finishing process
26 August 2012
Plasma Treatment of Wool
Plasma Treatment of Wool:
Wool is a protein fiber. It is obtained from the fleece of the sheep or lamb or hair of the Angora or Cashmere goat. The effects of a plasma treatment on wool has revolutionary changed such as anti-felting effect, degreasing, improved dyestuff absorption and increase in wetting properties have been discussed in this article.
Effects of Plasma Treatment on Wool:
Wool is a protein fiber. It is obtained from the fleece of the sheep or lamb or hair of the Angora or Cashmere goat. The effects of a plasma treatment on wool has revolutionary changed such as anti-felting effect, degreasing, improved dyestuff absorption and increase in wetting properties have been discussed in this article.
Effects of Plasma Treatment on Wool:
- Plasma treatment increases the fibre/fibre friction as measured by Roder method, but reduces the differential friction effect (DFE) as defined by Mercer and Lindberg.
- Plasma treatment does not change the strength and elongation; the breaking force in loop form is slightly reduced.
- The plasma treatment increases the top cohesion by a factor of 1.5-2.0; this increased cohesion remains stable after prolonged storage.
- The specific electrical resistivity does not change considerably after plasma treatment.
- The fatty matter content in wool is reduced by about one-third due to plasma treatment.
- The water content of the wool top is reduced by about 3% due to plasma treatment.
- There is changes in spinning behavior of plasma treated wool. The spinning aids applied on the first drawing frame are carefully selected. The rubbing intensity or twist of the slubbing should be increased. Reduction in breaks rate at ring spinning frame is usually observed and an increase in yam tenacity by 20-25% is observed for all yarns.
 |
| Treated and untreated of wool |
Plasma treatment of wool followed by
polymer application has also been studied. Almost all polymers used
currently on pre-chlorinated wool cannot be used on plasma-treated top.
Silicone resins applied to plasma-treated wool increase the shrinkage
over that for untreated wool. However, the combined plasma/PMS/Hercosett
treatment encompassing the top treatment gives excellent shrink
resistance. The polymer after-treatment reduces both relaxation and
felting shrinkage almost independently of plasma treatment time.
There is more even and quicker penetration of dyestuffs and chemicals on plasma treated wool than the untreated reference sample. The increased dyes and chemicals affinity is presumably attributed to the plasma induced oxidation of the cystine in the layer of the exocuticula and thereby to a reduction of the wetting bridge density in the fibre surface.
Surface analyses of wool fibres treated with different plasma gases reveal that the wettability, wickability, printability and surface contact angle of the materials are significantly changed in a direction that may lead to new uses for these materials. Several aspects affect the web wettability, such as pore size, fibre diameter, fibre surface roughness and fibre surface chemical composition. Chemical composition of the fibre surface is most important as it determines the surface bonding forces with water, i.e. disruption force, polar force, and H-bonding force. Surface roughness is not a primary reason for improved wettability, but it may increase it.
Plasma treatment increases the hydrophillic groups in the wool fibre and the cystine present in the surface layer is converted to cysteic acid. The endocuticle and the intercell membrane complex and the density of cross-links in the surface layer is decreased by the reactive species in the plasma gas and thus facilitate diffusion of dyes and chemicals. The internal lipids of cell membrane complex are also modified to a certain extent. These changes in the interior of the fibre are presumably caused by the short wave ultra-violet radiation which is produced by the low temperature glow-discharge plasma apart from the chemical active species such as electrons, radicals etc.
Woollen sliver and yarn have been treated in low temperature plasma in a vacuum chamber for times from 20 to 30 min. There is a significant increase in the strength which lead to better stability of the material during subsequent processing. Fabrics made from treated wool do not felt and also the shrinkage is reduced e.g. from 37% to 3-5%.
Plasma treated wool may exhibit more or less firm or harsh handle because of surface roughening. This property is very important for hand-knitting yarns or yarns for underwear fabrics. Softeners generally deteriorate the shrink resistance imparted by plasma treatment or plasma plus polymer after-treatment quite heavily. The enzyme treatment is capable of improving the handle of plasma treated wool as well as plasma treated and polymer after-treated hand-knitting yarns without imparting their shrink resistance.
Conclusion:
A lot of changes occur after plasma treatment on wool. Besides, atmospheric pressure plasma treatment of wool fabric, with a relatively short exposure time, effectively removed the covalently bonded lipid layer from the wool surface. The plasma‐treated fabric showed increased wettability and the fibres showed greater roughness. X‐ray photoelectron spectroscopy analysis showed a much more hydrophilic surface with significant increases in oxygen and nitrogen concentrations and a decrease in carbon concentration.
References:
There is more even and quicker penetration of dyestuffs and chemicals on plasma treated wool than the untreated reference sample. The increased dyes and chemicals affinity is presumably attributed to the plasma induced oxidation of the cystine in the layer of the exocuticula and thereby to a reduction of the wetting bridge density in the fibre surface.
Surface analyses of wool fibres treated with different plasma gases reveal that the wettability, wickability, printability and surface contact angle of the materials are significantly changed in a direction that may lead to new uses for these materials. Several aspects affect the web wettability, such as pore size, fibre diameter, fibre surface roughness and fibre surface chemical composition. Chemical composition of the fibre surface is most important as it determines the surface bonding forces with water, i.e. disruption force, polar force, and H-bonding force. Surface roughness is not a primary reason for improved wettability, but it may increase it.
Plasma treatment increases the hydrophillic groups in the wool fibre and the cystine present in the surface layer is converted to cysteic acid. The endocuticle and the intercell membrane complex and the density of cross-links in the surface layer is decreased by the reactive species in the plasma gas and thus facilitate diffusion of dyes and chemicals. The internal lipids of cell membrane complex are also modified to a certain extent. These changes in the interior of the fibre are presumably caused by the short wave ultra-violet radiation which is produced by the low temperature glow-discharge plasma apart from the chemical active species such as electrons, radicals etc.
Woollen sliver and yarn have been treated in low temperature plasma in a vacuum chamber for times from 20 to 30 min. There is a significant increase in the strength which lead to better stability of the material during subsequent processing. Fabrics made from treated wool do not felt and also the shrinkage is reduced e.g. from 37% to 3-5%.
Plasma treated wool may exhibit more or less firm or harsh handle because of surface roughening. This property is very important for hand-knitting yarns or yarns for underwear fabrics. Softeners generally deteriorate the shrink resistance imparted by plasma treatment or plasma plus polymer after-treatment quite heavily. The enzyme treatment is capable of improving the handle of plasma treated wool as well as plasma treated and polymer after-treated hand-knitting yarns without imparting their shrink resistance.
Conclusion:
A lot of changes occur after plasma treatment on wool. Besides, atmospheric pressure plasma treatment of wool fabric, with a relatively short exposure time, effectively removed the covalently bonded lipid layer from the wool surface. The plasma‐treated fabric showed increased wettability and the fibres showed greater roughness. X‐ray photoelectron spectroscopy analysis showed a much more hydrophilic surface with significant increases in oxygen and nitrogen concentrations and a decrease in carbon concentration.
References:
- Chemical Technology in the Pre-treatment Processes of Textiles by S.R. Karmakar
- Study of atmospheric plasma treatment of wool fibers by Illya Kulyk, Marco Scapinello, Matteo Stefan
- Ageing effect of plasma‐treated wool by Maryam Naebe, Ron Denning, Mickey Huson, Peter G. Cookson & Xungai Wang
10 August 2012
Wool Glazing Machine
Wool Glazing Machine
This special machine is used to perform functional finishing on wool fabrics after raising finishing. The machine is made up of two different units.
1.Starching Unit
2.Glazing Unit
The Starching Unit Includes:
1) a vat containing water and silicones;
2) a variable-speed extracting cylinder to reduce the quantity of liquid to be passed onto the fabric;
3) a brush coated with horsehair adhering to the extracting cylinder and passing the liquid onto the fibre ends of the fabric, simultaneously combing and lining up the fibres.
The Glazing Unit Includes:
The Starching Unit Includes:
1) a vat containing water and silicones;
2) a variable-speed extracting cylinder to reduce the quantity of liquid to be passed onto the fabric;
3) a brush coated with horsehair adhering to the extracting cylinder and passing the liquid onto the fibre ends of the fabric, simultaneously combing and lining up the fibres.
The Glazing Unit Includes:
- A crenellated polishing cylinder (made of steel and coated with hard chrome) heated by means of electric resistances at temperatures up to 220°C and four spiral grooves on which hard-steel combs are assembled. These combs have very fine teeth to enhance the efficiency of fibre ironing during the process;
- A felt sleeve, rotating at the same speed of the fabric, presses the fabric onto the polishing cylinder. The contact arc on the polishing cylinder can vary and the cylinder can reach a temperature of 130°C.
 |
| Wool glazing machine |
The
fabric with the fibre ends already combed and wet come under the
polishing cylinder, which dries and irons the pile, and confers a
lustrous appearance by giving a soft and smooth hand, also thanks to the
silicones added to the starching vat (thanks to this process the fabric
acquires a hand similar to the precious wool one).
By adjusting the temperature and the speed of the polishing cylinder, the contact arc of the fabric on the cylinder and the contrasting pressure of the felting material, it is possible to obtain different types of finishing (from the laid down to the perfectly lined up one).
http://textilelearner.blogspot.com/
By adjusting the temperature and the speed of the polishing cylinder, the contact arc of the fabric on the cylinder and the contrasting pressure of the felting material, it is possible to obtain different types of finishing (from the laid down to the perfectly lined up one).
http://textilelearner.blogspot.com/
27 July 2012
Worsted Wool
What is Worsted Wool?
Well, the differences between woollens and worsteds begin at the
carding stage. 'Carding' is one of the processes which untangles the
wool fibers and lays them straight, side by side. It also helps to clean
the fibers of debris. Both woollens and worsteds are carded.
'Combing' is the next process in establishing what is worsted wool. Combing removes shorter length fibers and helps to further straighten the fibers and lay them parallel. Combing also helps to clean more debris from the fibers. Only worsteds are combed.
During spinning, worsted yarns have more twist inserted which makes them a firmer, stronger yarn. This in turn makes worsted fabrics stronger than woollens.
While I'm explaining to you what is worsted wool, I should show you the different characteristics of worsted and woollen yarns and fabrics. Here you go...
Worsted Yarns
Worsted Fabrics
'Combing' is the next process in establishing what is worsted wool. Combing removes shorter length fibers and helps to further straighten the fibers and lay them parallel. Combing also helps to clean more debris from the fibers. Only worsteds are combed.
During spinning, worsted yarns have more twist inserted which makes them a firmer, stronger yarn. This in turn makes worsted fabrics stronger than woollens.
While I'm explaining to you what is worsted wool, I should show you the different characteristics of worsted and woollen yarns and fabrics. Here you go...
Worsted Yarns
- Have a long staple length (4 inch fibers and longer only)
- Are carded and combed
- Have a tight twist in spinning
- Are stronger
- Are finer, smoother, and have more even fibers
- Are harder
- Have a short staple (1 - 4 inch long fibers)
- Are carded only
- Have a slack twist
- Are weaker
- Are bulkier
- Are softer
Worsted Fabrics
- Have a distinct woven pattern and are more closely woven
- Have a hard finish for a flatter, smoother look
- Are firm, wiry or harsh, and smooth or rough
- Wrinkle less, are more long-lasting, and hold creases and shape
- Are more expensive and good for tailored clothing and suits
- Have a less obvious pattern
- Have a soft finish (maybe felted, or steamed)
- Are soft, thick and fuzzy
- Are warmer, and you can remove stains more easily
- Are usually less expensive and good for jackets, sweaters and blankets
2 May 2012
Chemical Composition of Natural Fiber
Chemical Composition of Natural Fiber:
Every fiber consists of some chemical elements. Such as cotton contains cellulose, protein, pectin etc. Wool contains keratin, dirt, suint etc. Chemical composition of natural fibers are given below:
Chemical Composition of Cotton Fiber:
Chemical Composition of Jute Fiber:
Chemical Composition of Linen/Flax Fiber:
Chemical Composition of Hemp Fiber:
Chemical Composition of Sisal Fiber:
Chemical Composition of Coir Fiber:
Chemical Composition of Wool Fiber:
Chemical Composition of Keratin:
Every fiber consists of some chemical elements. Such as cotton contains cellulose, protein, pectin etc. Wool contains keratin, dirt, suint etc. Chemical composition of natural fibers are given below:
Chemical Composition of Cotton Fiber:
- Cellulose 94%
- Protein 1.3%
- Ash 1.2%
- Pectin 1.2%
- Oil, Fat and Wax 0.6%
- Sugar 0.3%
- Pigment trace
- Others 1.4%
Chemical Composition of Jute Fiber:
- Cellulose 65.2%
- Hemicellulose 22.2%
- Lignin 10.8%
- Water soluble 1.5%
- Fats and wax 0.3%
Chemical Composition of Linen/Flax Fiber:
- Cellulose 92%
- Hemicellulose 2%
- Lignin 4%
- Others 2%
Chemical Composition of Hemp Fiber:
- Cellulose 77.77%
- Hemicellulose 10%
- Lignin 6.8%
- Pectin 2.9%
- Fat & wax 0.90%
- Water soluble 1.73%
Chemical Composition of Sisal Fiber:
- Cellulose 71.5%
- Hemicellulose 18%
- Lignin 6%
- Pectin 2.3%
- Fat & wax 0.5%
- Water soluble 1.7%
Chemical Composition of Coir Fiber:
- Husk 14%
- Fiber 22%
- Pith 16%
- Kernel 30%
- Water 18%
Chemical Composition of Wool Fiber:
- Keratin 33%
- Dirt 26%
- Suint 28%
- Fat 12%
- Mineral matter 1%
Chemical Composition of Keratin:
- Carbon 50%
- Hydrogen 12%
- Oxygen 10%
- Nitrogen 25%
- Sulfher 3%
Chemical Composition of Silk Fiber:
- Fibroin 76%
- Sericin 22%
- Fat & wax 1.5%
- Mineral salt 0.5
Subscribe to:
Posts
(Atom)