What is Drape? | Cusick Drape Test

Drape

Drape is the term used to describe the way a fabric hangs under its own weight. It has an important bearing on how good a garment looks in use. The draping qualities required from a fabric will differ completely depending on its end use, therefore a given value for drape cannot be classified as either good or bad. Knitted fabrics are relatively floppy and garments made from them will tend to follow the body contours. Woven fabrics are relatively stiff when compared with knitted fabrics so that they are used in tailored clothing where the fabric hangs away from the body and disguises its contours. Measurement of a fabric s drape is meant to assess its ability to do this and also its ability to hang in graceful curves.

Cusick Drape Test
In the drape test the specimen deforms with multi-directional curvature and consequently the results are dependent to a certain amount upon the shear properties of the fabric. The results are mainly dependent, however, on the bending stiffness of the fabric.

Drape Test

In the test a circular specimen is held concentrically between two smaller horizontal discs and is allowed to drape into folds under its own weight. A light is shone from underneath the specimen as shown in Fig. 10.4 and the shadow that the fabric casts, shown in Fig. A, is traced onto an annular piece of paper the same size as the unsupported part of the fabric specimen.

The stiffer a fabric is, the larger is the area of its shadow compared with the unsupported area of the fabric. To measure the areas involved, the whole paper ring is weighed and then the shadow part of the ring is cut away and weighed. The paper is assumed to have constant mass per unit area so that the measured mass is proportional to area. The drape coefficient can then be calculated using the following equation:

The higher the drape coefficient the stiffer is the fabric. At least two specimens should be used, the fabric being tested both ways up so that a total of six measurements are made on the same specimen. There are three diameters of specimen that can be used:

• A 24cm for limp fabrics; drape coefficient below 30% with the 30cm sample;
• B 30cm for medium fabrics;
• C 36cm for stiff fabrics; drape coefficient above 85% with the 30cm sample. 

Drape test top view of draped fabric

It is intended that a fabric should be tested initially with a 30cm size specimen in order to see which of the above categories it falls into. When test specimens of different diameter are used, the drape coefficients measured from them are not directly comparable with one another. Figure B shows a drape tester fitted with a video camera and computer for instantaneous measurement of the drape coefficient.

Bursting Strength Test | Diaphragm of Bursting Test

Bursting Strength

Tensile strength tests are generally used for woven fabrics where there are definite warp and weft directions in which the strength can be measured. However, certain fabrics such as knitted materials, lace or non-wovens do not have such distinct directions where the strength is at a maximum. Bursting strength is an alternative method of measuring strength in which the material is stressed in all directions at the same time and is therefore more suitable for such materials. There are also fabrics which are simultaneously stressed in all directions during service, such as parachute fabrics, filters, sacks and nets, where it may be important to stress them in a realistic manner. A fabric is more likely to fail by bursting in service than it is to break by a straight tensile fracture as this is the type of stress that is present at the elbows and knees of clothing.

When a fabric fails during a bursting strength test it does so across the direction which has the lowest breaking extension. This is because when stressed in this way all the directions in the fabric undergo the same extension so that the fabric direction with the lowest extension at break is theone that will fail first. This is not necessarily the direction with the lowest strength.

Diaphragm of Bursting Test
The British Standard describes a test in which the fabric to be tested is clamped over a rubber diaphragm by means of an annular clamping ring and an increasing fluid pressure is applied to the underside of the diaphragm until the specimen bursts. The operating fluid may be a liquid or a gas.

Two sizes of specimen are in use, the area of the specimen under stress being either 30mm diameter or 113mm in diameter. The specimens with the larger diameter fail at lower pressures (approximately one-fifth of the 30mm diameter value). However, there is no direct comparison of the results obtained from the different sizes. The standard requires ten specimens to be tested.

Bursting Strength Test

In the test the fabric sample is clamped over the rubber diaphragm and the pressure in the fluid increased at such a rate that the specimen bursts within 20 ± 3 s. The extension of the diaphragm is recorded and another test is carried out without a specimen present. The pressure to do this is noted and then deducted from the earlier reading.

The following measurements are reported:

• Mean bursting strength kN/m2 
• Mean bursting distension mm
• Liquid
• Piston
• Rubber
• diaphragm
• Specimen
• Clamp

The US Standard is similar using an aperture of 1.22 ± 0.3 in (31 ± 0.75mm) the design of equipment being such that the pressure to inflate the diaphragm alone is obtained by removing the specimen after bursting. The test requires ten samples if the variability of the bursting strength is not known.

The disadvantage of the diaphragm type bursting test is the limit to the extension that can be given to the sample owing to the fact that the rubber diaphragm has to stretch to the same amount. Knitted fabrics, for which the method is intended, often have a very high extension. 

Introduction of Nylon 6 Fiber | Spinning Process of Nylon 6 Fiber |Manufacturing Process of Nylon 6 Fiber

Nylon 6 Fiber

The synthetic fibres also called as chemical fibres are the synthesised polymers, which are not found in nature. There are different types of synthetic fibres of which the manufacturing process of nylon is discussed in this unit. Nylon is the first man made synthetic fibre (pure chemical fibre).

Nylon 6 Fiber

As defined by the Federal Trade Commission (FTC), nylon “is a long – chain synthetic polyamide in which less than 85 per cent of the amide linkages are attached to two aromatic rings”.

Manufacturing of Nylon 6
The raw material for manufacturing Nylon 6 is coal.Cyclohexane oxime is produced by a series of chemical reactions on coal. Cyclo heaxaneoxime is then treated with sulphuric acid to form caprolactum. The caprolactum is a monomer with 6 carbon atoms that are polymerized to from chains of caprolactum. Polymerization is done by gently heating it in a steam – jacked stainless steel vessel. The solution is stabilised as a super polymer under constant steam and pressure.

Nylon may be delustered by adding the delustering agents like titanium di oxide, barium sulphate, zinc oxide, and zinc sulphate. The molten nylon 6 polymer is allowed to flow onto a slowly revolving casting wheel. These are sprayed with cold water, which hardens it into milky white ribbons. The ribbons are transformed into flakes that are sent for spinning and are then drawn into the fibre form.

Spinning of nylon 6:

Spinning of Nylon 6
The spinning of the nylon fibres is carried out with melt spinning. There are two methods of melt spinning:

1. grid spinning
2. extruder spinning.

Grid spinning is employed for the production of finer filaments.The nylon flakes are made to fall on a hot grid that melts the nylon flakes. The molten nylon is pumped through a sand filter to the spinneret. The type of filament produced depends upon the number of holes on the spinneret, the size and the shape of the holes. The molten nylon as extruded from the spinneret solidifies and forms filaments as exposed to the air. Extruder spinning is generally used for heavier yarns.

The nylon chips flow by gravity into a device that forces them by screw action through the heated zones. The combined action of the heat and screw pressure melts the chips. The molten polymer is then extruded through the spinneret, which solidifies when the polymer comes in contact with the air.

Drawing:
The filaments obtained from spinning are stretched by drawing process. The drawing process is accomplished in two stages: unwinding the yarn from one godet, or wheel, winding it onto another godet that is rotating much faster. The speed of the second wheel determines the amount of cold-drawing or stretching. The yarn from the second godet is wrapped on a cylindrical tube called a pirn.

The filaments can be stretched from 2 to 7 times their original length. The molecules in the filament structure straighten out, become parallelized, and are brought very close together.

Calculation of Yarn Spinning

Count:

Count is the measure of fineness or coarseness of yarn.

Systems of Count Measurement
There are two systems for the measurement of count.
1) Direct System
2) Indirect System

1) Direct System
It is used for the measurement of weight per unit length of yarn. 

When count increases, fineness decreases. ( count↑ fineness↓ )

Commonly used units in this system of measurement are:-
1) Tex ( 1 Tex = 1g/ 1000m )
2) Grex ( 1 Grex = 1g/ 10,000m )
3) Denier ( 1 Denier = 1g/ 9000m )

2) Indirect System
It is used for the measurement of length per unit weight of yarn.
When count increases, fineness increases. ( count↑ fineness↑ )
 

Commonly used subsystems of indirect system are:-
1) English System ( 1 Ne = 1 Hank/ lb )
2) Metric System ( 1 Nm = 1 Km/ kg )

For cotton yarn, length of 1 Hank = 840 yards. Whenever the type of count is not mentioned with the count, it is understood that it is the English count.

Count Conversion Table

1) Calculate the length of a package of 80/1 and cone weight 2.083 lb.

(Note:- English count is represented as C/N i-e, yarn count/ no. of yarn plies)
Yarn type = 80/1
Cone wt. = 2.083 lb
Cone length = ?

Solution:
Length = Ne x lb x 840 yards

= 80 x 2.083 x 840 yards

= (139977.6÷ 1.0936 )m

= 127997.07 m ——————Ans.

2) Calculate the length of yarn with Ne (80/2) and weight 4.166 lb.
Yarn type = 80/2
Cone weight = 4.166 lb
Cone length = ?

Solution:
 Length = Ne x lb x 840 yards

= (80÷2)x 4.166 x 840 yards

= (139977.6÷1.0936)m

= 127997.07 m ———————-Ans. 


3) Calculate the draft at drawing frame if the feeding sliver is 68 grains/yard, delivered sliver is 48 grains/ yard and the number of doublings is 8 :-

Count of feeding sliver = 68 gr/ yd
Count of delivered sliver = 48 gr/ yd
Doubling = 8 (8 sliver cans used)
Draft = ?

Solution:
Actual draft = (count fed x doubling) ÷ (count delivered)                (direct system)

= (68 x 8)÷ 48

= 11.33——————-Ans.

4) Calculate the grains/ yard of delivered sliver if feeding sliver is 68, doubling is 6 and the draft is 7 :-
Count of F.S = 68
Count of D.S = ?
Doubling = 6
Draft = 7

Solution :
A.D = (F.S x D)÷ D.S

=> 7 = (68 x 6)÷D.S

=>D.S = 68 x 6 = 58.28 grains/ yard —————Ans.

5) Calculate the TPI on simplex if the diameter of back roller is 15/16”, rpm of B.R is 10, rpm of flyer is 1000 and draft is 6 :
TPI on simplex = ?
Dia. of B.R = 15/16”
Dia. of F.R = ?
Rpm of B.R = 10
Rpm of flyer = 1000 rpm
Draft, D = 6

Solution :
S.S of B.R =  πDN  =  π x 15/16” x 10 = 29.45”/ min

D = (S.S of F.R) ÷ (S.S of B.R)

=> 6 = (S.S of F.R)÷29.45

=> S.S of F.R = 6 x 29.45 = 176.71”/ min

TPI = rpm of flyer ÷ S.S of F.R   = 1000 ÷ 176.71 = 5.66 ————————-Ans.

6) Calculate the TPI (twists per inch) produced on a simplex with diameter of front roller 28 mm and its rpm be 30. The rpm of flyer is 1000.
TPI on simplex = ?
Dia. of F.R = 28 mm = 2.8 cm
Rpm of F.R = 30
Rpm of flyer = 1000

Solution :
Dia. of Front roller = 2.8 cm / 2.54             (1 in= 2.54 cm)
 

= 1.1023 inch

Surface speed of F.R, ^DN = π x dia. of F.R x rpm of F.R

= π x 1.1023 x 30

= 103.88 “/ min.

TPI = rpm of flyer ÷ S.S of F.R = 1000 ÷ 103.88
 

= 9.63 ————————-Ans.

Introduction of Tea Dyeing | Dyeing Mechanism of Tea Dye/Tea DyeingProcedure

Tea Dyeing

Tea dyeing is an easy way to mute fabrics or give them an older, antiqued look or even to give it a sun-bronzed Caucasian complexion. Tea will stain the fibres, giving them an irregular stain over the whole piece, rather than an even colour. Tea produces a tan colour to your fabric.

Apparatus: 

1. Cotton fabric or items made from cotton, linen, silk. 
2. Tea bags or loose black tea 
3. Hot /boiling water  
4. Containers to hold the tea bath

Approx 1 pint of boiling water to 6 tea bags or 8 ounces of loose black tea to half metre fabric

Dyeing Mechanism of Tea Dye/ Tea Dyeing Procedure:
1. Bring water to the boil and add your tea bags. Allow to ‘steep’ for 5-10 minutes. 

2. Remove/Squeeze out the teabags if you wish, as if you leave them in they could disintegrate and spot the fabric with tea leaves. 

3. Soak the fabric in this tea-stew for about 30 to 45 minutes, depending on the shade required. Wet fabric always looks darker than dry. 

4. Stir the fabric to reduce any blotchy effect as it rises above the surface of the tea mixture. (NB: the more fabric you use the more water you’ll need to cover it and the lighter the final colour will appear, unless your dye solution is strong.

5.Give the cloth a light rinse and allow to dry. You will loose a lot of the colour doing this, so if it isn’t dark enough, soak it in the dye bath for longer. (If you prefer to tumble dry, always wipe out the drum of your machine afterwards with a damp cloth).

If you have dyed some fabric and then decide you don’t like it, rinse it in the washing machine with a little bleach. Also if the colour is too dark when dry, wash with a very small amount of bleach (1 tablespoon bleach to 1 gallon of water). This will lighten your fabric slightly. Repeat this process if the colour is still too dark.

Do this on fabrics that are safe for bleach only. Most cotton deteriorates with time and bleach is very harsh on older fabrics, so make sure that the older items you treat can handle the bleaching process.

Fiber Fineness is Measured by the Airflow Method

Principle:
In this method, fiber fineness is measured by air flow. If large amount of air is blown, the fiber will be coarse and if small amount of air is blown, the fiber will be fine. The method based on this principle.

This is an indirect method of measuring fibre fineness which is based on the fact that the airflow at a given pressure difference through a uniformly distributed mass of fibres is determined by the total surface area of the fibres . 

(a)

(b)

Fig: Fiber Fineness is Measured by the Airflow Method

The surface area of a fibre (length X circumference) is proportional to its diameter but for a given weight of sample the number of fibres increases with the fibre fineness so that the specific surface area (area per unit weight) is inversely proportional to fibre diameter; Fig. shows this diagrammatically. Because the airflow varies with pressure difference it is the ratio of airflow to differential pressure that is determined by the fibre diameter. Therefore the method can be used to measure either the airflow at constant pressure or the pressure drop at constant airflow.

The measurement of airflow at constant pressure is the more usual form of apparatus with wool. For fibres of approximately circular cross-section and constant overall density such as unmedullated wool, the estimate of fineness corresponds to the average fibre diameter as determined by the projection microscope with a good degree of accuracy.

What is Sampling? | Zoning Sampling Technique

Sampling:

It is not possible or desirable to test all the raw material or all the final output from a production process because of time and cost constraints. Also many tests are destructive so that there would not be any material left after it had been tested. Because of this, representative samples of the material are tested. 

The amount of material that is actually tested can represent a very small proportion of the total output. It is therefore important that this small sample should be truly representative of the whole of the material. For instance if the test for cotton fibre length is considered, this requires a 20 mg sample which may have been taken from a bale weighing 250kg. The sample represents only about one eleven-millionth of the bulk but the quality of the whole bale is judged on the results from it. 

The aim of sampling is to produce an unbiased sample in which the proportions of, for instance, the different fibre lengths in the sample are the same as those in the bulk. Or to put it another way, each fibre in the bale should have an equal chance of being chosen for the sample.

There are several techniques for sampling fiber. Here is given the most popular sampling method.

Zoning Sampling Technique:
Zoning is a popular testing method of fiber that is used for selecting samples from raw cotton or wool or other loose fibre where the properties may vary considerably from place to place. A handful of fibres is taken at random from each of at least 40 widely spaced places (zones) throughout the bulk of the consignment and is treated as follows. 

Each handful is divided into two parts and one half of it is discarded at random; the retained half is again divided into two and half of that discarded. This process is repeated until about nix fibres remain in the handful (where n is the total number of fibres required in the sample and x is the number of original handfuls). Each handful is treated in a similar manner and the fibres that remain are placed together to give a correctly sized test sample containing n fibres. The method is shown diagrammatically in fig. It is important that the whole of the final sample is tested. 

 Sample from each zone

Zoning Sampling Technique

What is Pretreatment? | Objective of Pretreatment | PretreatmentProcess of Cotton and Natural Fibers

Pretreatment:

Natural fibers and synthetic fibers contain primary impurities that are contained naturally, and secondary impurities that are added during spinning , knitting and weaving processes.Textile pretreatment is the series of cleaning operations.All impurities which causes adverse effect during dyeing and printing is removed in pretreatment process.

Pretreatment machine

Pretreatment processes include desizing, scouring, and bleaching which make subsequent dyeing and softening processes easy. Uneven desizing, scouring, and bleaching in the pretreatment processes might cause drastic deterioration in the qualities of processsed products, such as uneven dyeing and decrease in fastness.

Objective of Pretreatment:

• To Convert fabric from hydrophobic to hydrophilic state.
• To remove dust, dirt etc from the fabric.
• To achieve the degree of desire whiteness.

Steps in Pretreatment Process of Cotton and Natural Fibers:

Major steps involved in textile pretreatment are,

1. Singeing
2. Desizing,
3. Scouring,
4. Mercerization
5. Bleaching.

Steps in Pretreatments for Wool:

1. Raw wool scouring; aqueous and/ or solvent washing
2. Carbonizing
3. Scouring (desizing)
4. Fulling /crabbing/thermo fixing
5. Easy-care treatments
6. Anti-felting anti-shrinking treatments
7. Wool Bleaching

Steps in Pretreatment of Silk:
To prepare a silk yarn for dyeing and silk fabrics for dyeing and printing, it is necessary to partially or completely remove sericin, as well as natural oils and organic impurities. Depending on the percentage of sericin removed during scouring (sericin is present in raw silk in a ratio between 20 % to 25 %), the end-product is defined as unscoured (used only for shirts and suits), `souple’ or degummed.

1. Degumming
2. Scouring
3. Bleaching

Pretreatment Of Synthetic Textile Materials:
Although mots of the synthetics do not need to be given a very strong pretreatment however the possible steps in pretreatment of synthetics are

1. Desizing
2. Heat setting
3. Washing
4. Bleaching if necessary

Requirements to Become A Merchandiser | How To Become A Merchandiser

In garment industry, merchandiser is the BRIDGE between the management(or)industry and the buyer. He have to look after every job like buying the raw material (which is requied to finish the product), making the garment, finishing the garment, documentation(over all view), finally shipping.

He is the responsibility person to make the product.

The merchandiser who creats a good relationship in between exporter & buyer.

A Merchandiser Should have below Requirements :

*Reliable Computer With Internet Connection And A Printer Many companies will send you job information and ask you to input work information through their web sites.

*Good People Skills- you will need to cultivate good relationships with job schedulers, store staff and customers during your visits, so a patient, pleasant attitude and willingness to help is always a plus.

*Initiative- especially when you’re starting out. YOU are responsible for finding your own work. DON’T get scammed by people selling lists or info that GUARANTEE jobs. It doesn’t work that way!

*Ability to work on your own- AKA Personal Responsibility!

You will have to make sure you have all your paperwork and materials together, and that the work is done to the best of your ability. You also need to report and/or send all of the required documentation to the company completed in a timely manner, ie: BEFORE the stated deadline. Deadlines in merchandising must be strictly observed.

*Good English Skills- brush up on your reading, writing and comprehension if you’re rusty. Many vendors ask for detailed information regarding the store, associates, and other things you noticed during your store visit.

*Reliable Transportation & Childcare-

Note: You CANNOT take children with you on jobs for safety reasons.

*Digital or Cell Phone Camera- You may be required to take pictures of completed displays for the vendor. These are usually sent by email.

*A Credit Check And/Or Drug Test- some stores require EVERYONE who works there to have a credit and/or drug test for security reasons.

A Merchandiser don’t need:
*A Bad Attitude
*To Pay For Legitimate Jobs Or Information

Not Required, But It Helps

Home Office Equipment- Look into the purchase of a FAX machine, paper shredder and other office supplies to help you organize your work and be professional.