Sunday 16 August 2009

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.

Want to Take a Quick Test on this Topic. Click Here

Friday 7 August 2009

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.  

Monday 3 August 2009

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.

Sunday 2 August 2009

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.

Saturday 1 August 2009

Amazing Explanation of Cotton, Wool and Silk Fabric



An Amazing dictionary of the cotton, silk and wool fabrics is given in this directory of Internet Centre of Canadian Fashion and Design.

It is different from the other dictionaries in that the explanation is divided into four parts: Fiber, Weave, Characteristics and uses.

The following Fibres are covered:

Cotton Fabrics:
Armure Batiste Birdseye Broadcloth Brocade Buckram Butcher Linen Calico Cambric Candlewick Fabric Canton Flannel Canvas Chambray Chamois Cloth Chamoisette Cheesecloth Chenille Fabric Chino Chintz Chite Corduroy Cotton Crepe Crettone Denim Dimity Domett Flannel Dotted Swiss Drill Duck Flannelette Fustian Gabardine Gingham Homespun Hopsacking Jersey Lawn Madras Monk's Cloth Nainsook Organdy Oxford Percale Pique Plisse Point d'esprit Poplin Provence Sailcloth Sateen Seersucker Terry cloth Tiking Velveteen Velour Vichy Voile Whipcord

Wool Fabrics
Agneline Albert Cloth Astrakhan Barathea Beaver Cloth Bedford Cord Birdseye Blanket Cloth Bolivia Bombazine Boucle Broadcloth Cavalry Twill Challis (Chalys) Cheviot Chinchilla Covert Crepe Doeskin Donegal Duvetyn(e) Eponge (Souffle) Felt Flannel Wool Flannel Worsted Flannel Fleece Gabardine Homespun Hopsacking Jersey Wool Jersey Doubleknit Kersey Lambswool Loden ClothMackinaw Melton Monk's Cloth Montagnac Pin Check, Pinhead and Pick Pyrenees Repp or Rep Serge Sharkskin Shatush Shetland Suede Tricotine Tropical Worsteds Tweed Harris Tweed Venetian Viyella Whipcord Wool Zibeline

Silk Fabrics
Bayadere Bengaline Brocade Brocatelle Camocas Cendal Chiffon China Silk CrepeCrepe-back satin Crepe de ChineCreponGeorgette CrepeFlat CrepeMoss Crepe Degummed Silk Doupion, Douppioni Duchesse Faconne Faille Foulard Frise Glove Silk Habutai Honan Illusion Lame Marquisette Matelasse Messaline Mousseline de Soie Moire Net Ninnon Organza Ottoman Panne Peau de Cynge Peau de Peche Pongee Rajah SatinSatin-back Crepe Satin-backDouble-face SatinDuchessSatin FaconneSlipper SatinPaillette SatinPeau de Soie Shantung Sharkskin Sheer Silk Spun Rayon Surah TaffetaFaille TaffetaPaper TaffetaPoumpadou TaffetaShot TaffetaTissue TaffetaWarp-print TaffetaTricot Tulle Tussah VelvetCisele VelvetFaconne VelvetLyons VelvetNacre VelvetPanne VelvetPlushTransparent VelvetUtrecht VelvetVelvet Satin

I just wish it were supplemented by pictures !!
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