Micro spinning or How to produce yarn at 40% cheaper than the conventional ring frame

As per the Site of Ministry of Rural Development “This technology is developed by Vortex pertains to the stages preparatory to spinning (pre-spinning). This can be coupled with a conventional spinning frame to produce yarn economically at a scale that is 1/100th of the prevailing scale. The technology integrates the operation of seed-removal (Ginning) with in-situ handling of fibres to produce slivers.”

Microspinning is a process of spinning in which small quantities of yarn can be produced. This is unlike in case of a standard spinning mill where large quantities of yarn need to be produced in order to be viable. In a spinning mill, the use of bales is the major cause of producing large quantities. It is also seen that pre spinning process is the major factor in making the textile mills bigger in size.

Micro spinning process eliminate the use of bales and convert directly cotton picked from fields to slivers. Thus it does away with the process of first converting the fibers into bales and then make it into uncompressed state. It will thus make possible for a spinner to produce as low as 30 tonnes per year of a medium quality of yarn (33s count) and therefore spinning can be brought in line with other small scale processes which can be done in small quantities such as dyeing and weaving. Weaver will get more returns ( about 20%) as a result of inhouse spindles (minimum 8 spindles onwards) the cost of setting up also reduces drastically.

Each microspinning unit from cotton to yarn will cost about 10 lakh rupees and therefore is an excellent investment for a small size entrepreneur. Total power requirement for a 24 spindle unit producing 3kg hank yarn per eight hours is less than 2 KW which is excellent for a power starved country like India. It required as area as low as 500 sq feet and can be installed in the field itself. As far as profitability of the unit is concerned, it is claimed that even at 40% capacity utilization, the profitability of a micro spinning unit will be seven times greater than the average spinning mill.

The possible issue here is the quality of yarn produced by microspinning unit as compared to the mill spinning. But I guess it would be ideal for low speed powerlooms and handlooms and will serve its purpose excellently.

Any success Stories ? Yes, there are many. According to website of Society of Elimination of Rural Poverty “The first unit has been running successfully in Chirala in Andhra Pradesh for the last 6 years and the cloth produced through this process is called “Malkha” cloth. Chirala unit has attained viability and sustainability and is being developed as a resource center for micro spinning and it is producing 1500 meters cloth per month and expected to increase to 1800 meters per month by April 2009”.

Other Links

Textile Spinning

India Together

Project Report
General Report

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Direct TV

DirectTV provides television and audio services to subscribers through satellite transmissions. The Services are equivalent to that of many local television services, broadcast television networks, subscription television services, satellite audio and private video services. Subscribers have access to dozens or hundreds of channels.

Small reception antennas are used to accept the services.

Consumers who purchased DirecTV equipment subscribe to various packages of Direct TV programming for which the subscriber pays a monthly fee. A subscriber also can order pay-per-view events and movies. DirecTV contracts with and pays program providers such as cable networks, motion picture distributors, sports leagues, event promoters, and other programming rights holders, for the right to distribute their programming to its subscribers.

All programming distributed by Directv is delivered to its broadcast centers in California, where it is then digitized and compressed. The resulting signal is encrypted, or electronically scrambled, by DirecTV to prevent its unauthorized reception. DirecTV then transmits these signals to several satellites located in stationary orbit approximately 22,300 miles above the equator from where these were directed to individual customer’s antenna.

Ringframe Productivity

Cotton Yarn prices are sky-rocketing, thanks to the failure of crops in China and India and rising export demands in developing countries. It is but obvious, that the companies dealing in yarn are making or expected to make huge profits in the coming quarter. The profitability is going to be even more for the composite textile mills where value addition is more. All this is leading to rise in the stock prices of Textile Companies in India and I am sure everywhere else in the world. I am bombarded from friends dealing in share market with requests of how to calculate various indicators to judge the operating efficiency of a spinning organization. One of the question being how to calculate the production per spindle in a ring frame.

Kilogram per spindle depends upon the count, spindle speed, efficiency of ring frame and twist per inch. In general, higher the count, lower the kilograms per spindle. Similarly higher the twist per inch, lower the kilograms per spindle. Ring frame efficiency varies from 90-93%, it decreases as the count increases with about 91% for 20s and 93% for 40s count. A formula for calculating the kg per spindle is given in the second link below.

As a rule of thumb, a mill with an average 70s count will be giving .200 kg per spindle per day, a mill with 35s count will give approx double, that is .400 gms per day. Similarly production in Kg per day for other counts can be calculated.

Bibliography

Loyal Textiles

Article of Mr. P.L. Chiang

Venerated Mr. Vijay Kumar's Observations

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Textile Used in Trade Displays

It is trendy to use textiles specifically designed to display company information. This is specially useful when exhibiting the company’s products in trade shows and trade fairs. The most commonly used articles of display are trade show flooring, trade show carpets, logo mats and logo canopies.

Trade show flooring is primarily used in trade shows, it comes in a variety of styles and shapes. There is even a line of printed flooring, so that end users can add a logo or message to the flooring.

Trade show carpets are a great help for exhibitors and add to a nice comfortable touch to any exhibit.

Logo mats are primarily used in offices, stores, retail outlets and retail chains. These can be printed in several different ways. Inlaid logos are common and full digital images can be produced.

Printed logo canopies using EZ Up products and other styles of printed tents are used by a wide variety of companies selling products on the go. Great for outdoor events, these canopies are the mainstay of presenters at all types of fairs and festivals.

Needless to say, Textiles customized for the exhibitors can go a long way in capturing the prospective customers in an elegant and non-obtrusive way.

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Count, Construction and Width of common Cotton Fabrics

Please note that value in bold represents count. The values afterwards represent EPI ( Ends per inch) and Picks per inch. Then the available widths are given in inches.


Cotton Drill Fabrics


16 X 12 /96 X 48 / 48",63", 93" , 98", 120"

20 X 20 / 108 X 56 / 48", 63", 93" , 98" , 120"

20 X 16 / 108 X 56 / 48", 63" , 93 ", 98" , 120"

30 X30 / 124 X 64 / 48", 63", 93", 98", 120"

40 X 40 / 144 X 72 / 48", 63 ", 93" , 98 " , 120"



Linen/Cotton Fabrics

88 X 64 / 20s X 20s Linen / 63"

72 X 68 / 20s X 16s Linen / 63"


Cotton Oxford Fabrics

84 X 38 / 2 / 20s X 2/ 20s / 48", 63"

84 x 28 / 16 X 8 / 48 " , 63"

108 X 72 / 20 X 16 / 48", 63"


Cotton Poplin Fabrics

92 X 88 / 40 X 40 / 50" , 63"

100 X 80 / 40 X 40 / 50" , 63"

100 X 92 / 40 X 40 / 50" , 63"

124 X 64 / 40 X 40 / 48" , 63"

124 X 72 / 40 X 40 / 48" , 63"

132 X 72 / 40 X 40 / 48" , 63"



Cotton Twill Fabrics

124 X 64 / 30 X 30 / 48 " to 120"

132 X 72 / 40 X 40 / 48 " to 120"

144 X 74 / 40 X 40 / 48 " to 120"

144 X 74 / 50 X 50 / 48 " to 120"


Cotton Voile Fabrics

92 X 88 / 80 X 80 / 48 ", 63 "

92 X 104 / 80 X 80 / 48 ", 63 "

80 X 80 / 80 X 80 / 48 ", 63 "

100 X 92 / 80 X 80 / 48 ", 63 "


Cotton Satin Fabrics

100 X 80 / 40 X 40 / 98 " , 120"

132 X 72 / 40 X 40 / 120"

124 X 64 / 30 X 30 / 120"

144 X 72 / 40 X 40 / 120"

175 X (56 X 2) /  60 X 60 / 120 " - 300 TC

175 X (50 X 4) / 60 X 80 /120 "  - 400 TC

195 X ( 72 X 4) / 80s X 100s X 120 " -500 TC

195 X ( 86 X 4) / 80s X 100S X 120" - 600 TC

175 X 146 / 4 / 120s X 2 / 120s / 120" - 1000 TC



Cotton Bedford Fabrics

132 x 72 / 40x40 / 48" & 63"

144 x 100 / 60x60 / 48" & 63"

124 x 100 / 40x40 / 63"

144 x 72 / 50x50 / 63"


Cotton Cambric Fabrics

132 X 108m / 60 X 60 / 48",54",63"

92 X 88 / 60 X 60 / 48" , 54", 63"

132 X 72 / 50 X 50/ 48" , 63"

124 X 100 / 50 X 50 / 63 "


Cotton Plain Fabric or Cotton Sheeting Fabrics

44 X 40 / 10 X 10 / 48", 63", 93", 98" , 120" to 143"

60 X 60 / 16 X 16 / 48 " , 63 ", 93" , 98" , 120" to 143"

60 X 60 / 20 X 20 / 48 " , 63 ", 93" , 98" , 120" to 143"

68 X 68 / 30 X 30 / 48 " , 63 ", 93" , 98" , 120" to 143"

72 X 68 / 30 X 30 / 48 " , 63 ", 93" , 98" , 120" to 143"

Fiber Length and Spinning Performance

Fiber length in spinning is important because it influences spinning limit, yarn strength, evenness and hairiness. It also contributes to the handle and luster of the product by influencing the number of turns of twist required. It influences productivity via the end breakage rate and end breakage rate.

In general, fibers less than 4 to 5 mm are lost at the spinning stage. Fibers from 12 to 15 mm do not contribute to strength but only to the fullness of the yarn. It is only fibers greater than 15mm in length that produce other positive characteristics in the yarn.

Fiber length after carding is most important. Conditions at card and fiber characteristics should be such that the fibers survive carding without noticeable shortening in length.

The fiber lengths can be assessed with the help of a staple diagram.

Remember that the fibers in the boll do not show extremely great length differences. Noticeable differences arise even before the spinning starts. This happens due to mechanical working on the fibers at the ginning and

cleaning stage.

Rectangular Staple

Such diagram is achievable with synthetic fibers.

However such lengths can cause problems in drafting as in drafting stage fibers do not move individually but in bunches, thereby producing a high degree of unevenness.

Triangular Staple

It lends itself to better processing than rectangular staple diagram. However, it produces too many short fibers which cannot be maintained under control. Thus it produces hairy yarn.

Trapezoidal Staple

The fibers depicting such diagram are ideal for processing.

Stepped Staple

It indicates that fiber materials of different lengths are mixed in wrong proportions. It has the disadvantage that fibres move only in bunches which produce a high degree of unevenness.

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Influence of Fiber Fineness and Maturity in spinning Process

Influence of Fiber Fineness and Maturity on spinning Process

Fiber Fineness

Fiber fineness determine how many fibers are present in the cross section of a yarn of given thickness. Additional fibers in the cross section not only provide additional strength but also a better distribution in the yarn. Minimum 30 fibers are needed, usually over 100 fibers are required. Fiber fineness influences spinning limit, drape of the fabric, yarn strength, luster, yarn evenness, handle, yarn fullness and productivity. Productivity is influenced by reduced end breakage rate.

In a conventional spinning process, fine fibers accumulate to the core and coarse fibers in the periphery.

Fiber fineness is measured in dtex which is equal to ratio of mass in dgrams and length in km. Decitex is equal to the product of Micronaire value of the cotton and 0.394.

Cotton fibers are generally classified as very fine if they have a micronaire value upto 3.1; fine if they have value between 3.1 to 3.9; medium if they have it between 4.0 to 4.9; slightly coarse between values of 5 to 5.9 and coarse if they have a micronaire value above 6.

Fiber Maturity

Cotton fiber consists of cell wall and lumen. The maturity index depends upon the thickness of the cell wall. The fibers are considered ripe if they have maturity index between 50-80 percent, unripe if they have MI between 30 to 45% and dead when they have it less than 25%.

Unripe fibers have neither adequate strength nor adequate longitudinal thickness. They lead to loss of yarn strength, neppiness, high proportion of short fibers, varying dyeability, processing difficulties mainly at the card.

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Fiber Identification - Burning Test- Man-made Fibers

Viscose Rayon 

All viscose including High Wet Modulus scorch and ignite quickly when brought near the flame. Like cotton they burn quickly with yellow flame when in the flame. When removed from the flame they continue to burn. There is no afterglow unlike cotton. The smell is that of burning paper. They leave a light gray and feathery ash.

Acetate Rayon  ( And Triacetate Rayon)

When brought near the flame, it fuses away from flame turning black. When in the flame, it flames quickly. The fabric puckers, sputters and melts. It drips like burning tar. When removed from the flame, it continues to burn and melt. It smells like vinegar. It leaves a brittle hard, irregular black ash which is difficult to crush.

Nylon 

Image via Wikipedia

Nylon fuses and shrinks away from the flame when brought near the flame. In flame, it burns slowly without melting. When removed from flame the flame diminishes and tends to die out. It has somewhat pungent odor. It leaves a hard, round, tough and gray bead.

Aramid  ( Nomex)

When brought near the flame, it shrinks away from the flame. When in the flames it puckers and chars. When removed from flame, it extinguishes by itself. It has no smell and it leaves a hard black bead.

Polyester  

Image via Wikipedia

Polyester fuses and shrinks away from flame. When in flame, it burns slowly with melting. When removed from the flame, it burns with difficulty. It has slightly sweetish smell. It leaves a hard round brittle, black bead.

Acrylics 

Orlon, Acrilan and Creslan and Zefran fuse and melt away from Flame when brought near the flame. When in flame Orlon flames rapidly. The fiber puckers, sputters and melts. Acrilan flames rapidly and melts. Creslan flames and melts and Zefran sputters slightly and flames. When removed flame all of acrylics continue to burn and melt. Orlon has a slightly burning meat-like smell. Acrilan has a buring steak smell. Creslan has sharp sweet smell and Zefran has a turmeric like smell. Orlon, Acrilan and Cresla have hard, brittle and irregular black bead. Zefran has irregular black ash that can be crushed easily.

Modacrylics

Verel and SEF fuse and shrink away from the flame when approached near a flame. When in flame, Verel burns very slowly with melting. SEF shrinks, melts and smolders. When removed from flames, all modacrylics are self extinguishing. Verel has a gunpower smell whereas SEF has a sharp sweet smell. Verel leaves a hard and irregular black bead whereas SEF leaves a hard and irregular black bead.

Spandax 

Fuses but doesn’t shrinks away from the flame when approached near the flame. When in flame, it burns with melting. It has an acrid smell. It leaves a soft, fluffy black bead.

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Identification of Natural Fibers by Burning Test

Identification of Natural Fibers by Burning Test


Cotton

When cotton is brought near the flame it scorches and ignites readily. In the flame it burns quickly with yellow flame. Upon removing from flame it continues to burn rapidly and shows afterglow. It emits a smell of burning paper. The Ash is light, feathery and grayish. If the ash is black it denotes mercerized cotton.

Linen

Linen like cotton when brought near the flame scorches and ignites easily. In the flame it burns slower than cotton with yellow flame. Upon removing from flame it continues to burn with a smell of burning paper. The ash residue is feathery and gray.

Wool

Wool when brought near the flame smolders. In flame it burns with small and slow flickering flame. Also in flame it sizzles and curls. When removed from flame it ceases to burn. The Odor is like that of burning feather or hair. It gives crisp, dark and irregular shaped ash that can be crushed easily.

Pure Silk

Pure silk smolders when brought near the flame. In the flame it burns slowly with sputtering. When removed away from flame it continues to burn but with difficulty and ultimately extinguishes. The smell that is emitted is like that of burning feathers or hair but it is less pronounced than wool. It gives out a round, crisp, shiny black beads that can be crushed easily.


Weighted Silk

Weighted Silk smolders when brought near the flame. In the flame it burns with a glow. When removed from flame the burned part becomes briefly incandescent then it slowly chars. The smell is like that of pure silk i.e. burning feather or hair. The ash brings a screen like skeleton of original sample.

The following guide is very handy in identifying the fibers by burning test:

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13 things to ensure while cutting

Cutting Room Procedures ( Image Source)

 1. Knife guard should be adjusted according to the height of the lay.

2. The correct position of the blade, its sharpness and the reciprocating speed of the machine should be ensued.

3. Cut the lay of fabric by propelling the cutting machine on the marking line with accuracy.

4. Projections for each pattern section should be provided to facilitate the sorter in numbering the cut sections.

5. Provide notches at appropriate places with required depth.

6. Mark the position of pockets, embroidery, logo etc. by drilling small hole through the lay with correct drill bit .

7. Frayed, serrated, fused or scorched edges, ripped or pulled yarns, overcut and undercut should be avoided while cutting.

8. On Bend knife machine, use ready patterns aided by appropriate fixtures for carrying out precision cutting.

9. Sections which need to be cut individually (e.g. checks to be aligned in the front panel) are to be respread and folded by aligning the checks/stripes.

10. Use appropriate fixtures to ensure the matching of the folded sections.

11. Discard the cut scrap into the caster bins positioned near the table.

12. Tie the cut lay along the cut sections of the master marker in a bundle.

13. Erase the splicing and the end marks after the spread is cut and bundled.

Safety Instructions in Handling Cutting

a. Areas near cutting tables should be clearly marked, and their access restricted should be restricted by barriers.

b. On motorised and automatic cutting tables the warning signals should be fitted to indicate when blade is in motion.

c. The machine ideally should be fitted with automatic adjustable guards to fully cover the exposed part of the cutting blade.

f. The five finger chain blades should be available to all the operator working on knife and should be worn on all times during cutting work.

g. There should be a regular check on the condition of the light, guard, and table fittings.

h. Only fully trained operatives should be allowed to work on knives.

i. The operators' standards should be checked against the published operating practice on a regular basis and should be corrected wherever a deviation is found.

j. There should be an effective cleaning system in operation that prevents build up of fluff, fly and off cuts, thus reducing fire, health & trip hazards?

A complete of list of safety measures can be found here


For those who want to go in for technical details they can click here for round knife and here for straight knife .

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The Sari- Some Facts, Methods, Techniques and Measurements

The Sari has not lost its appeal in modern India. Despite the growth of Women Western and other modern outfits, the charm of Sari remains. 

A users manual on How to Wear a Sari can be found here or here . A visual guide to various styles is presented here.

An amazing classification of  Different Saris of India can be found on the site of Indiangarment.com. You can find a complete manual of Indian Saris here.

A very nice manual on the measurement for various Indian garments such as Churidars, Parallels, Sharara, Lehnga Chunni or Ghahgra Choli and blouses is given on the same site.

And of course, an interesting concept of Automatic Sari is also given.

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Animation- Weaving Principles and Fabric Structure

1. Relationship between Draft, Peg Plan, Denting Plan and Design- Click Here

2. Weave and Color Combination - Click Here

3. Principle of Double Cloth Formation- Click Here

4. Principle of Tubular Fabric - Click Here

5. Double Cloth based on Exchange Principle- Click Here

6. Principle of Terry Towel Weaving- Click Here

7. Principle of Weaving Leno Fabric- Click Here

8. Principle of Weaving  Velvets and Corduroys- Click Here

9. Principle of Jacquard- Click Here

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A Few Notes About Fiber Chemistry

1. All fibers are formed from polymers, are not the only products containing polymers

2. Polymer means many units. Each individual molecule is known as monomer and the process of joining all the monomers together to form long chain molecules (polymers) is known as polymerisation.

3. The degree of polymerisation is the number of monomers units in the polymer. These may be of same type ( a homopolymer ) or two different randomly arranged monomers ( a copolymer)

4. There are two types of polymerisation: addition polymerisation, where all the atoms present in the monomers are also present in the polymer and condensation polymerisation where some small molecules are eliminated during polymerisation.

5. Polypropylene and acrylic polymers are produced by addition polymerisation.

6. Polyester, polyamide, wool, silk, cotton, flax, jute and viscose polymers are produced by condensation polymerisation.

7 There are three types of intermolecular forces. In decending order of strength: they are hydrogen bonds, polar bonds and Van der Waal's forces.

8. The properties of polymers for good fiber formation are: high degree of polymerisation, good intermolecular forces, linear and regular arrangement of monomers, high orientation of molecules and an inflexible repeat unit.

9. Crystalline regions are highly ordered areas within the fibers. They give the fiber its tensile and rigidity properties.

10. Amorphous regions are where the molecules are not closely packed within the fibers. They give the fiber its flexibility, extensibility and elasticity.

11. In natural fibers, crystalline regions develop as the fiber grows. In MMF, the ratio of crystalline to amorphous regions can be altered by drawing and heat setting.

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Cloth setting and Fabric Geometry Theories

1. Fractional Cover is defined as d/p where d is the diameter of the yarn and p is the thread spacing.

2. There are various theories for calculation of yarn diameter. According to Law yarn diameter d is equal to 1/ sqrt (Fn) where F is 500 for worsted yarn, 800 for cotton yarns, 530 for woolen n being worsted and cotton and Yorkshire count respectively. According to Ashenhurst yarn diameter d = 1/(F sqrt(N)), where F is .95, .9,.84 for cotton, worsted and woolen yarns respectively and n= yds/lb. According to Pierce, yarn diameter is 1/(28 sqrt(N) where N is the English count.

3. Ashenhurst Diameter  intersection theory says that when the count of warp and weft are the same, it is assumed that an intersection takes up as much space as a thread. Then Threads/inch (T) can be determined as equal to D x W/ (W+I) where D is the diameter per inch of yarn, W is the threads in one repeat of weave and I are the intersection in one repeat of weave. For plain weave W =2, I=2 for 2/1 twill weave, W=3 and I = 2.

4. Curvature theory says that T = D x W/ ( W +.732 I), the notations being the same as in point 3.

5. Armitage Maximum Setting Theory says that cloths which are similarly built are equally firm. For regular twill weaves Threads per inch (T) = Sqrt (6 x C(F+4)) where C are the counts of worsted yarn and F is the average float of weave. For other weaves, Armitage gave the following “setting ratio” instead of (F +4). For plain weave it is 4.75, for 2/2 hopsack it is 6.25, for 4 end satin it is 6.5 for 5 end, 6 end and 8 end satin it is 7.5, 7.75 and 9.0 respectively.

6. Laws Maximum Setting suggests that T = ((D x F)/ (F+1) )+ various percentages where F is the average float and D is the diameter per inch. For common weaves like plain weave T = ( D X 1)/(F+I), for twill weave T= ((DF)/(F+1))+ 5% for each float exceeding two, for satin weave T = ((DF)/(F+1))+5.5% for each float, for hopsack weaves T= ((DxF)/(F+1))+ 4.5% for 2 floats and 9.5% for floats exceeding two.

7. Brierjey’s Maximum Setting suggests that square settings vary according to the formula T= sqrt (KC x (F)^m) where C is the average count of yarn, F is the average float, K is a constant varying according to kind of yarn and numbering system: it is 134 for worsted yarn, 200 for cotton yarn and 60 for york shire yarn. m is a constant varying according to the type of weave: For twill weaves it is 0.39, for Satin weaves it is 0.42 and for plain and hopsack weaves it is 0.45.

An amazing treatment on fabric geometry is done in this presentation.

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Why Wool Feels Warm

Image via Wikipedia

Why Wool is Warm to Wear- Heat of Sorption

When a fiber absorbs water, heat is evolved. It results from the attractive forces between the fiber and water molecules. The phenomenon occurs due to the fact that when moisture vapour is absorbed into fiber’s internal structure, it transforms from gas to liquid and the phase change produces the rise in temperature.

It is calculated by heat of wetting. It is the heat evolved when a specimen of the material at a given regain, whose dry mass is one gram is completed is completed wetted.

It is expressed in joules per gram ( of dry material)

The heat of wetting is greatest for the more highly absorbing fibers and is very small in the non-hygroscopic fibers. Thus it is 113 J/g for wool, 106 for viscose, 69 for silk, 55 for flax, 46 for cotton , 73 for mercerized cotton and only 34, 31,5 and 7 respectively for Acetate, Nylon, Polyester and Acrylic.

As we can see from the figures above, wool has the highest heat of sorption. And this heat raises the temperature of the wearer which makes the wool feel warmer. In fact “the heat of sorption from a kg of Merino can be equivalent to the output from an electric blanket over eight hours” (Source ).

You can also find some discussion on Heat of Sorption here.

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Why Fiber Fineness is so Important

Why Fiber Fineness is So Important

It has been known since long that fiber fineness plays an important role in determining the quality of resultant yarn and hence that of the resultant fabrics. In general fiber fineness is important due to the following factors:

1. It affects Stiffness of the Fabric

As the fiber fineness increases, resistance to bending decreases. It means the fabric made from yarn of finer fiber is less stiff in feel. It also drapes better.

2. It affects Torsional Rigidity of the Yarn

Torsional rigidity means ability to twist. As fiber fineness increases, torsional rigidity of the yarn reduces proportionally. Thus fibers can be twisted easily during spinning operation. Also there will be less snarling and kink formation in the yarn when the fine fibers are used.

3. Reflection of Light

Finer fibers also determine the luster of the fabric. It is so because they there are so many number of fibers per unit area that they produce a soft sheen. This is different from Hard glitter produced by the coarser fibers. Also the apparent depth of the shade will be lighter in case of fabrics made with finer fibers than in case of coarser fibers.

4. Absorption of Dyes

The amount of dye absorbed depends upon the amount of surface area accessible for dye out of a given volume of fibers. Thus finer fibers leads to quicker exhaustion of dyes than coarser fiberes.

5. Ease in Spinning Process

Finer fibers leads to more fiber cohesion because the number of surfaces are more so cohesion due to friction is higher. Also finer fibers lead to less amount of twist because of the same increased force of friction. Which means yarns can be spun finer with the same amount of twist as compared to coarser fibers. Which also means that the yarns will be softer.

6. Uniformity of Yarn and Hence Uniformity in the Fabric

Uniformity of yarn is directly proportional to the number of fibers in the cross fibers. Hence finer the fiber, the more uniform is the yarn. When the yarn in uniform lit leads to other desirable properties such as better tensile strength, extensibility and luster. It also leads to fewer breakages in spinning and weaving. In fact fiber fineness is one of the dominant factor in determining the limiting count to which a yarn can be spun.

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8 Things to Remember While Spreading Fabric

Things to remember While Spreading

1.      Mark the Splice Zone on the Spreading Table

Spreading is an operation in which bolts of fabrics are unrolled on a table in such a way in order to produce a multi-layer stack, so as to facilitate cutting.

Fabrics usually contain many defects. The defects in pieces which are cut into patterns are highly undesirable. To avoid this, the spreading operator must identify and cut out defects as the material is being spread on the table. However, if the material is cut in the mid of the pattern, it will lead to more material wastage.

To avoid this, zones are defined called splice zones, where cuts can be made by the spreading operator. Also it is also required to decide about the overlap of the next section of cloth. Thus there are two lines in a splice zone: One line shows how far the previous piece of cloth must extend, and one line shows where the next piece of the cloth must begin, ie how much overlap is needed.

Thus when a flaw is encountered, the spreader is stopped, the operator moves back to the nearest splice point, cuts the flaw out and moves the spreader back to overlap the cut line with the required overlap.

Apart from cutting out defects, splices are also used to achieve proper shade matching when starting a new roll of cloth.

Thus the splicing points are marked by means of a chalk or paint.

2.      Use Paper for the first ply in case the table surface is rough or when fine fabrics are being spread

3.      Identify the defects noticed in the fabric by means of stickers

4.      Use lubricated paper for separating layers

a.       To prevent scorching in the natural fibers ( coarse fabrics)

b.      To prevent fusing in the synthetic fabrics

5.      Ensure that decided number of ply count and height of the spread is achieved.

6.      How to spread

a.       Mount the bolt on the machine

b.      Pull the fabric to far end position

c.       Position the fabric at the far end ( with our without weight or pins)

d.      Align the ply ( width on one side)

e.       Cut the ply after each lay

f.       Repeat this process from b-e until the entire bolt is spread.

g.      Check ply count

h.      Repeat a and then b to g till the decided number of ply are spread

i.        Mark the remnants of the bolts with length in meters and bolt number and stack separately at the given place.

7.      How to Splice

a.       When the ends of the patterns in a marker are joined on both sides by straight line then use the single line splicing. Make sure that overlapping at this point should be about 2”

b.      When the ends of the patterns in a marker interlock at a common vertical line across the width then use two line marking with a diagonal indicating common area that must be overlapped when patterns in a marker interlock at a common vertical line across the width.

8.      When the required height of lay is achieved, place the marker on the spread and secure it by means of brass pins on each pattern section.

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Additional Reading: Indian Textile Journal

Comparison of Various Printing Techniques

Comparison of Various Printing Techniques

There are various printing techniques available. All have their unique points as well as shortcomings. It would be worthwhile to compare them in order to appreciate and use them for a particular end use.

Handblock Printing: It yields very low production, there is more downtime of ‘machine’. The cost of set up is very less. Very skilled personnel is required to do such printing. The cost of making a design is very less, however durability of design is very low, being defined by durability of block, usually made of wood. The variety of designs is dictated by the skill of the woodworker who carves those designs. The size of design pattern repeat can be larger. There is a limitation of width of the fabric- which is dictated by the width of the table. The printing can be very bold or subdued. In fact, in India there are numerous techniques based on a twin combination of natural dyes and block printing.

Roller Printing: Yields more production , machine downtown is very less, however cost of setup is high- as investment is needed for the maching. The space required is less. Again very skillful operators are required. The cost of making a design is more, as roller has to be carved. The durability of the design is more than a handblock print. Very elaborate and fine designs can be carved on a roller printing. The repeat size is limited to upto 42 cm. Again it has a limitation of fabric width. Very bold and lustrous prints cannot be done on a roller printing.

Flat Bed Screen Printing: Yields more production but less than roller printing as the process is not continuous. There is very less downtime of the machine. The cost of machine and installation is very high. The space requirement is also very high. Very less skilled workers are needed for this printing method. The cost of making a design is less as compared to a roller printing. The durability of the design however is very less, as new screen has to be made after few uses. The quality of designs can be very fine. The repeat of pattern can be very high. Also even a higher width cloth can be printed. The colors can be very bright and bold.

Rotary Printing: It has the maximum production among all printing techniques. The machine downtime is very less. The cost of machine and space requirement is again very high. Less skilled workers can be employed to operate this machine. Cost of making a design is very high. Compared to this the durability of the design is very less. The variety of design it offers and the quality of reproduction is the best among all techniques. Also fabric width can be high for it to be printed. It can yield bright colors.

Transfer Printing: It can do printing only on synthetic fibers such as polyester. One cannot get a ‘tone effect’ in this printing. Even unskilled workers can be used for this technique. However 100% color is not transferred so reproducibility is affected. Paper can’t be used again after one printing therefore its durability is the minimum of all techniques. The cost of making a design is very high. The production is about equal to that of flat bed. There is very less downtime of the machine. Space requirement is very less, infact, less than any other printing technique.

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Major Warping Defects- On Sectional warping

Snarlings and Overlappings

These are caused by irregular yarn tension. The broken end is not tied-up by the operative with the yarn end on the drum.

Different lenghts of sections, High Wastage Rate

This is caused by over-or-under warping of sections, untimely laying of lease cords due to faulty operation of the counter and the carelessness of operative.

Overlapping/Excessive Distance

The sections overlap each other or there is an excessive distance between them. This is caused by support improperly set and the careless of warper operative.

Stripiness in the Warp

This is caused  by improper mixing of raw material

Irregular Winding

Irregular winding on the warper's beam which is displaced towards one end. This is due to improper position of the weaver's beam in warp beaming.

Different lenghts of Ends

It also includes irregular distribution of the section in the weaver's beam width. This is caused by improper fixing of section ends to the weaver's beam.

Excessive or insufficient number of yarn ends in the warp

This is caused by improper calculation at gaiting.

Warp Beaming on a defective weaver's beam

This is caused by carelessness of the assistant foreman and the warper operative.

Incorrect Laying of lease cords, or their absence in some sections

Again this is caused by carelessness of the warper operative.      

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Suitability of a fiber for a blend

Fibers in a blend are chosen keeping in mind various properties of the constituent fibers. Thus a blend is chosen which gives the best of properties of the different constituents of the blend. The properties that are considered can be strength, absorbency,crease resistance, resistance to abrasion, resistance to heat, bulkiness,resistance to pilling and Dimensional stability.All the fibers do not have all the properties that are desired. This is the very reason why blend is chosen.

Cotton has moderate strength and dimensional stability. However, it is excellent in absorbency, resistance to heat and pilling. It has an average resistance to abrasion and poor bulkiness properties and crease retention.Thus it is added in the blend to have excellent absorbency properties.

Viscose Rayon has excellent absorbency, resistance to heat and pilling. Thus it is similar to cotton in these properties.It has however, poor resistance to abrasion, bulkiness, crease retention and stability. It has an average strength. It has absorbency properties similar to cotton. It is also cheaper than cotton.

Acetate Rayon has excellent resistance to pilling and stability. It has moderate resistance to heat and average absorbency, crease retention and stability. However its resistance to abrasion is very poor.

Wool has excellent absorbency, bulk and wrinkle resistance. However, it has poor stability. It has moderate abrasion and heat resistance. Its crease retention, resistance to pilling and strength can only be considered as average.

Nylon has excellent strength, stability and abrasion resistance. However, It has poor absorbency and bulk. It has moderate crease retention and average resistance to heat and pilling.

Polyester has excellent strength, stability, crease retention and abrasion resistance. However it has poor absorbency, bulkiness properties and resistance to pilling. Its resistance to heat is average.

Acrylic has excellent bulk and stability. It has moderate resistance to heat and average crease retention and strength. Its resistance to abrasion and pilling and absorbency are very poor.It is similar to wool in most of the properties. It is also cheaper than wool.

Modacrylic has excellent stability and bulk properties. However its absorbency, resistance to heat and pilling is very poor. It has average strength, resistance to abrasion and crease retention.

Polypropylene and Polyethylene have excellent stability and strength. They have poor absorbency, bulk and heat resistance. The have average crease resistance and resistance to pilling.

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Seam Strength Vs. Seam Slippage

Difference Between Seam Strength and Seam Slippage

Both the parameters measure the performance of seam. Seam strength referes to the strength when seam finally ruptures or when the fabric breaks.

However before rupturing there is an unacceptable opening in the seam which makes the seam 'failed' commercially even when there is no visible rupture. Seam slippage measures that.

Seam strength depends upon stitch type, thread strength, stitches per inch, thread tension, seam type and seam efficiency of the material.

Seam slippage depends upon the stitch rate, the weave structure of the fabric and the width of the seam allowance.  

There is another term called 'yarn slippage' which measures the shifting of warp yarn over weft yarn to render the garment unusuable. 

Yarn slippage depends upon a low number of warp or filling yarn, two shallow seam allowance, too tight a fit and improper seam construction.  

Find Pictures of Seam Quality Defects here.

Fabric Parameters

Woven fabric parameters

There are four basic parameters that are essential for every woven fabric.

1. Ends per Inch and Picks per inch (EPI and PPI).
2. Yarn count
3. Crimp

4. Weave or Fabric Structure or Design

1. Ends per Inch or Picks per Inch

It is a measure of thread density. The normal method used to determine thread density is to use a pick glass.

2. Yarn count

EPI and PPI affects the compactness of the fabric. It is also known as thread count or cloth count. Thread counts range from as low as 20 threads per inch as used in tobacco cloth to as high as 350 threads per inch, found in type writer ribbon fabrics. Normally EPI and PPI of a fabric are described as EPI×PPI. Thus a fabric of 74×66 means 74 EPI×66 PPI.

Balanced constriction

A fabric is said to be well balanced if the number of warp yarns and weft yarns per inch are almost equal.

3.Crimp

Crimp refers to the amount of bending that is done by thread as it interlaces with the threads that are lying in the opposite direction of the fabric. Crimp is defined as the ratio of difference of length of yarn (Ly) taken from length of fabric (Lf) to the length of fabric (Lf).

Crimp = (Ly-Lf)/Lf

Often it is more convenient and preferable to use percentage values. Thus we can define crimp percentage as:

Crimp% = (Ly-Lf)/Lf

A crimp will normally give values ranging from 0.01 to 0.14 ie. (1% to 14%).

Crimp is related to many aspects of the fabric. It affects the cover, thickness, softness and hand of the fabric. When it is not balanced it also affects the wear behaviour and balance of the fabric, because the exposed portions tend to wear at a more rapid rate than the fabric. The crimp balance is affected by the tensions in the fabric during and after weaving. If the weft is kept at low tension while the tension in warp directions is high, then there will be considerable crimp in the weft and very little in the warp.

4. Weave

It refers to the arrangement of warp and weft in the fabric.

OTHER FABRIC PROPERTIES

1. Fabric weight (W)

It is the weight of the yarn per square meter in the woven fabric, which is the sum of the weight of the warp (W1) and weight of the weft (W2).

Weight of the warp is calculated as (per square m):

W1= [n1 x 100 (1+c1%)/100] x [N1/1000] g

Where
n1 = Ends per cm
N1 = Warp count in Tex

C1% = Warp crimp percentage.

Similarly weight of the weft is calculated as (per square m)

W2= [n2 x 100 (1+c2%)/100] x [N2/1000] g

Total weight per square meter = W1+W2

weight/piece = (W1+W2) × piece length × piece width in gram.

Example

A fabric 120m long, 1.3 m wide and having 30 ends per cm of 12 tex warp and 24 picks per cm of 15 tex weft. The warp and weft crimp percentages are five percent and eight percent respectively. We describe these fabric particulars as
30×24; 12 tex × 15 tex; 5%×8%

Warp weight per square m = [30 x 100 x (1+5)/100] x [12/1000] = 37.8 gms

Weft weight/square m = [24 x 100 x (1+8)/100] x [15/1000] = 38.8 gms

Piece weight

= total weight per m × piece length × piece width
= 76.68 × 120× 1.3
= 11962.08 gm or 11.96 kg.

2. Cover factor

(K) it is defined as the area covered by the yarn when compared with the total area covered by the fabric.
The warp cover factor can be found by using the formula.
k1= n1 x sqrt(N1)/10
Where
n1 = Ends/cm
N1 = Count of warp in tex

Similarly the weft cover factor can be found by the formula

k2 = n2 x sqrt(N2) /10

So the total cover factor is
K = K1 + K2

Thus with fabric (30×24; 12 tex×15 tex) the values are

k1= (30 x sqrt12)/10 = 10.39

k2 = (24 x sqrt15)/10 = 9.30

K = K1+K2 = 10.39+9.30 = 19.69

3. Fabric Thickness

For a wide range of fabric, this parameter is not important, but it becomes critical for fabrics that are to be used as belts and felts.

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Care of Linen Fabrics

Care of Linen Garments

1. Washing

Washing is recommended. One can use hand or machine washing but take care of the following points

- Use a gentle wash cycle and use a gentle soap.
- Use cool to warm, not hot water.
- Wash colored linens in cool water.
- Use soft water
- Use oxygen bleaches ( hydrogen peroxide) for white linen. Chlorine bleaches can cause yellowing.
- Never wash darker-colored pieces together with the lighter colored articles.
 

2. Drying

Can use any of the drying methods, but bring linen in while it is still damp. If linen dries thoroughly, it may become brittle. Damp Linen also helps in ironing. If a linen has become thoroughly dried, put them in a plastic bag in the refrigerator before ironing.

3. Ironing

Iron with lot of steam at a medium to hot setting. Iron Linen until smooth but not dry. Once wrinkles are gone, hang the linen items until it is bone dry.

4.Storing

Clean linen items before storing .

-Avoid folding linen garments. Linen clothing should be hung on a padded clothes hanger in a cool dry environment.

- If you decide to warp the linen, use bags of linen, cotton or muslin, never plastic bags.  

Tags: Care, Linen, Fabrics

Career in Journalism

Career in Journalism

Being a specialist helps. It helps more if you can deliver that specialised knowledge to the general audience in a way that is interesting and that they can understand. A career in Journalism is one of the options that a Textile Technologist or a Textile specialist can pursue. This is all the more relevant because entertainment and media are one of the hottest careers in the days to come.

An effort to this direction has been made by 9.9 School of Convergence by introducing a course called Diploma in Applied Journalism .The admissions are open with the session starting from September 20th. The aim of this course is to inculcate in a person some high quality editing, writing and reporting skills. The classes are scheduled on Sundays so that the professionals don't have to leave their regular jobs. One can contact them and find more about the details.

As their website suggests, their placement services or "career services" do more than just getting a student a full time job. The career is shaped from the beginning of the course looking at a person's abilities and aspirations. The 9.9 School of Convergence has 100% placement with clients like NDTV, STAR, CNN-IBN to boast of . The leadership team has Dr. Pramath Raj Sinha, Dr. Eric D Saranovitz, Pooja Kothari and Gunjan Aggarwal who have links deep into the media industry.

It can be understood that with a specialisation and a career in journalism, the jobs will be much more enriching and satisfying ( and more lucrative) than with a specialisation alone.

How to Resist Print using Reactive Dyes

How to resist print using reactive Colors

In resist printing using reactive colors, non-carbonic acids such as Tartaric Acids or Citric acid can be used.These acids act as resist agents. As acids are used therefore such a thickner is selected that does not degrade in acid. Here Methylhydroxy-ethylated cellulose ethers are used.
The following resist paste formula is used to print on the fabric:

For White Resist

Citric Acid- 50 gms
Water- 50 gms
Thickener- 600 gms.
To recognise the the printed design, sometimes tints such as CI Acid Blue-1 can be used. Also Fluorescent Brightening Agent can also be used which is visible in UV light.

After printing, the substrate is padded with concentrated solution of reactive colors, containing very less amount of Sodium Bicarbonate.The color is fixed after drying the cloth.

The following formule is used to:

1. Pad the cloth:

Reactive color: 20 gms
Resist Salt: 7 gms
Hot Water: 393 gms

Mix the three, let the solution to cool and then add the following chemicals:

3% Sodium Bicarbonate: 500 gms
Thickner: 80 gms
Make it to 1 kg.

2. Fixation Solution:

Caustic Soda -32.5%: 20ml
Glauber's Salt : 200 gms
Common salt: 100 gms

Make it to 1 liter.
Now steam the fabric for 20 seconds after padding with fixation solution.

For Color Resist

Thickner (Cellulose Ether): 100 gms
Emulsifier: 8 gmsWater: 110 gms
Pigment Binder:140 gms
White Spirit: 617 gms
Phosphoric or if Roller printing then Tartaric Acid: 120 gms

Print the fabric with the formula as given above. Then pad with reactive colors and Dry. Then Steam the cloth for 2-10 minutes, rinse and dry.

Disclaimer: Please test on a small piece before going for full fledge project. The receipe is meant to be used by professionals who know the behaviour of various chemicals and their interactions. Take all the precautions in handling chemicals. Don't use any combination of chemicals about which you don't know the outcome.