TEXTILE TESTING PDF

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TEXTILE TESTING LAB MANUAL MSC CDF Experiment - 1 Determination of Tensile strength of the given fabric Aim To measure the tensile strength of the given fabric by using texsile strength tester. Apparatus Tensile strength is the most important property of a fabric. In almost every fabric development ...

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TEXTILE TESTING LAB MANUAL

MSC CDF

Experiment - 1

Determination of Tensile strength of the given fabric Aim To measure the tensile strength of the given fabric by using texsile strength tester. Apparatus Tensile strength is the most important property of a fabric. In almost every fabric development and manufacturing, tensile properties are reported. Modulus, breaking strength and elongation at break are widely used for quality control. A tensile testing machine working on one of the following principles is used. a) Constant–rate–of–traverse (CRT) b) Constant–rate–of–loading (CRL) c) Constant–rate–of–extension (CRE) The load range of the machine shall be such that all the observed values would lie between 20 and 80 percent of the full–scale load. There are different types of fabric tensile tests that are used depending on the fabric and purpose: strip tensile test, grab tensile test and wide width tensile test.

 In the strip tensile test, a narrow strip of fabric sample is used (ASTM D5035 Breaking Force and Elongation of Textile Fabrics). The jaws of the tensile testing machine, which are wider than the fabric sample, clamp the sample on both ends and a tensile load is applied until fabric breaks. In the grab tensile test, the jaws are narrower than the fabric width to reduce the effect of Poisson’s ratio (ASTM D5034 Breaking Force and Elongation of Textile Fabrics).

 Grab tensile test is more widely used for heavy industrial fabrics such as geotextiles.

 Wide width tensile tests are also used mostly for industrial textiles (e.g. ASTM D4595 for geotextiles). Narrow fabrics such as webbings, ribbons, etc., are usually tested at full width. Fabric modulus is measured using ASTM Test Method D 885. Specifications of textile machines for tensile testing are described in ASTM D 76.

The terminology of tensile properties of textiles is given in ASTM D4848. Other ASTM test methods related to tensile testing include:

 ASTM D 1775 Standard Test Method for Tension and Elongation of Wide Elastic Fabrics (Constant Rate-of-Load Type Tensile Testing Machine)

 ASTM D 4964 Tension/Elongation of Wide/Narrow Elastic Fabrics by Constant Rate of Elongation Type Tensile Testing Machine 1

GOPALAKRISHNAN DURAISAMY

TEXTILE TESTING LAB MANUAL

MSC CDF

Sampling 1. Test at least five warps way and five weft way test specimens. 2. As far as possible, only one test specimen shall be drawn from a piece in the test sample. Incase the lot size is small, more than one test specimen may be drawn from a piece in the test sample. Calculations 1. Calculate the mean breaking load separately for warp way and weft way test specimens. 2. Calculate the elongation at break separately for warp way and weft way test specimens and calculate the mean percentage elongation at break as follows: Formulae Tensile strength = load at break/ (Original width x original thickness)

% Elongation = (Elongation at rupture / gauge length ) x 100

Sl.No

Breaking load

Elongation scale

Tensile strength

% Elongation

For WARP 1 2 3 4 5 For WEFT 1 2 3 4 5

Result Tensile stregth and Elongation % of the given fabric is identified and measured. **************** 2

GOPALAKRISHNAN DURAISAMY

TEXTILE TESTING LAB MANUAL

MSC CDF

Experiment - 2

Determination of Stiffness of the given Fabrics By cantilever principle test

Aim To find out the stiffness of given fabric by using shirley stiffness tester. Method For the purpose of the test method, the following definitions shall be used. 1. Stiffness: Resistance of the fabric to bending. 2. Flexural Rigidity: This quantity is the measure of the resistance of cloth to bending by external forces. It is related to the quality of stiffness that is, the cloth having a high flexural rigidity tends to feel stiff. 3. Bending Length: Bending length equals half the length of a rectangular strip of fabric that will bend under its own weight to an angle of 41.50. It is also equal to the length of a rectangular strip of material that will bend under its own weight to an angle of 7.10. It is expressed in centimetres. Standards – IS 6490: 1971 This method is used for determination of stiffness of fabric made from any textile fibre or a blend of two or more textile fibres. This method of test is not suitable for fabrics which are very limp or which curl or twist badly when cut in to small pieces. In general, this method is more suitable for testing woven fabrics than for testing knitted ones.

Preparation of Test Specimens 1. From the samples cut rectangular warp way and weft way test specimens of 25 mm × 200 mm size with the help of the template. 3

GOPALAKRISHNAN DURAISAMY

TEXTILE TESTING LAB MANUAL

MSC CDF

2. Specimens cut in each direction shall be scattered as far as possible so that no two warp way specimens contain the same set of warp yarns and no two weft way specimens contain the same set of weft yarns. 3. Avoid selvedge (within 10cm), end portions, creased or folded parts of the specimen. The specimen shall be handled as little as possible. Tabulation: Sl.No

Bending length

Flexural regidity

Overall flexural regidity

Remarks

1 2 3 4 5 6 7 8 9 10 Avg Procedure 1. Place the tester on a table or bench so that horizontal platform and inclined reference line are at eye level of the operator. 2. Adjust the platform with the help of a spirit level so that it is horizontal. 3. Place one of the specimens on the platform with the scale on top of it lengthwise and the zero of scale coinciding with the leading edge of the specimen. 4. Start pushing the specimen and the scale slowly and steadily when the leading edge of the specimen projects beyond the edge of the platform. An increasing part of the specimen will over hang and start bending under its own weight. 5. Keep an eye in such a position that the two inclined line (of the inclined plane making an angle of 41.50 with the horizontal) of the tester coincide. 6. Stop pushing the specimen when its tip reaches the level of the inclined plane. 7. Note down the length of the over hanging portion from the scale to the nearest millimetre. 8. Take four readings from each specimen with each side up, first at one end and at the other. 4

GOPALAKRISHNAN DURAISAMY

TEXTILE TESTING LAB MANUAL

MSC CDF

9. The weight per unit area can be determined by weighing all the warp way and weft way test specimens together after completion of stiffness test. Calculations 1. Determine the bending length, the flexural rigidity for warp way and weft way specimens and the overall flexural rigidity by the following formula: a) Bending length

C = L/2 cm

Where, L = the mean length of over–hanging portion in centimetres. b) Flexural rigidity

G = W × (L/2)3 mg–cm

Where, W = weight per unit area of the fabric in milligrams per square centimetre. c) Overall flexural rigidity

G0 = √Gw × Gf

Where, Gw = warp way flexural rigidity, and Gf = weft way flexural rigidity. Result The stiffness of given fabric is measured as per the test procedures and methods.

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GOPALAKRISHNAN DURAISAMY

TEXTILE TESTING LAB MANUAL

MSC CDF

Experiment - 3

Determination of Fabric Abrasion Resistance of the given fabric by the Martindale Method

Aim To find out the Abrasion Resistance of given fabric by the Martindale Method. Method Abrasion resistance is the ability of a fabric to resist surface wear caused by flat rubbing contact with another material. There are two different test methods commonly used by the textile industry to assess abrasion resistance: Wyzenbeek and Martindale (described in detail below). Because both of these test methods are limited to measuring flat abrasion resistance of a textile, they do not consider edge abrasion or other types of surface wear that may occur in actual upholstered applications. ASTM D4966-98** Martindale The Martindale testing process requires fabric samples to be mounted flat and rubbed in an enlarging elliptical T shape using a piece of worsted wool cloth as the abradant. The end point is reached when two yarn breaks occur or when there is an appreciable change in shade or appearance. Shade change is assessed as the AATCC gray scale rating of 3 or lower. Atmospheric status Testing atmosphere: Relative humidity - 65%+/-2% & Temperature - 270+/-20C. Present atmosphere: Relative humidity - 68% & Temperature - 290. Sample Preparation 1. When cutting specimens, avoid wrinkles, folds or creases. 2. Avoid getting oil, water, grease, etc. on the specimens when handling. 3. Using the smallest cutting die, cut six circular specimens from the fabric to be tested with each specimen being 1.5 inches (38mm) in diameter. Take care not to apply too much pressure on the cutting die as it will break the razor blades. 4. Weigh one specimen to determine pre-test mass. 5. Also use this measurement to determine mass/unit area. 6. At first cut the fabric into 4 pieces according to the measurement of the instrument. 7. Weigh these 4 pieces of fabric samples. 8. Now place these samples in the instrument under a certain load as supplied in the instrument. 9. Now start the machine and observe the counter of abrasion no. 6

GOPALAKRISHNAN DURAISAMY

TEXTILE TESTING LAB MANUAL

MSC CDF

10. After an abrasion of 200 bring out the first sample and weigh it. 11. After an abrasion of 300 bring out the second sample and weigh it. 12. Similarly after abrasion of 400 and 500 bring out the third and fourth sample and take their weight. 13. Now put the weights before and after abrasions in a table and find out their wear index. Preparation of Test Apparatus 1. Make all tests in the standard atmosphere for testing. 2. Remove the specimen holders from the Martindale tester by a. Loosening and lifting off the black knobs on top of the tester. b. Removing the silver covers held on by the black knobs. c. Lifting the specimen holders out 3. Note that all three parts of the specimen holders (handle, face, and ring) are numbered 1-6 and correspond to numbers on top of the Martindale tester. 4. Assemble the holder by: a. Placing the cut specimen with the technical face down into the gold ring. b. For specimens having a mass/unit area of less than 500 grams per square meter, place a disk of polyurethane foam between the specimen and the metal face. c. The face must sit flush and square inside the ring. d. Screw the handle back on. 5. Place the assembled holders into the machine, replacing silver caps and black knobs. 6. Add the required weight (9kpa for apparel, 12kPa for upholstery) by resting the weights on the ends of the handles. (kPa = 1 kilo Pascal = # pounds) Note that the weights are also numbered 1-6. 7. Set the counter system to record the desired movements using the third black button from the right. Starting the abrasion tester 1. Turn the power on. 2. The machine should already be programmed to run a batch of 500 movements. 3. Push the green button to start the batch 4. After the first batch is complete take specimen holders off of the machine and observe And record the results and changes in specimens. 5. Put specimens back on the machine and continue with the test. 6. Observe and record the results after each batch of 500 movements until you have Reached the desired number of movements (total of 3500). 7

GOPALAKRISHNAN DURAISAMY

TEXTILE TESTING LAB MANUAL

MSC CDF

The end point if reached for a woven when two or more yarns have broken, or for a knitted fabric when a hole appears. Tabulation Sample wt. before abrasion (mg)

S/No

No. of abrasion cycle

Sample wt. before abrasion (mg)

Wt. loss

Wear index

1 2 3 4 Calculation Wear index for 200 cycle = ......... Wear index for 200 cycle = ......... Wear index for 200 cycle = ......... Wear index for 200 cycle = ......... Remark It is easily understood that the more is no. of abrasion cycle the more will be the wt. loss of fabric. That is when a fabric is used more it losses its weight more. Now depending on yarn quality, fabric design and above all end use this loss may be less or more, again may be quickly or lately. But indeed the fabrics will loss its weight and serviceability. Result The abrasion resistance of given fabric is measured as per the fabric prepared according to ASTM D1776 and the specimens were tested as directed in Test Method D4966.

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GOPALAKRISHNAN DURAISAMY

TEXTILE TESTING LAB MANUAL

MSC CDF

Experiment - 4

Determination of Fabric crease recovery of the given fabric by Shirley Crease Recovery tester

Aim To find out the crease recovery of given fabric by the Shirley Crease Recovery tester. Method Crease is a fold in fabric introduced unintentionally at some stages of processing. Crease or crushing of textile material is a complex effect involving tensile, compressive, flexing and torsional stresses. Crease recovery is a fabric property which indicates the ability of fabric to go back to its original position after creasing. Crease recovery is a measure of creases resistance, specified quantitatively in terms of crease recovery angle. To measure this, the popular instrument is Shirley crease recovery tester. The instrument consists of a circular dial which carries the clamp for holding the specimen. Directly under the centre of the dial there is a knife edge and an index line for measuring the recovery angle. Crease recovery is determined depending upon this recovery angle. If the angle is 0° then recovery is zero and if the angle is 180° then recovery is full. Crease recovery depends on the construction, twist of yarn, pressure, time etc. Usually crease recovery is more in warp way than in weft way. This is because warp yarns are well in quality, strength, treated with sizing, kept in more tension during weaving etc.

Sample  

Cotton woven fabric. Size: 4.4 X 1.5cm. 9

GOPALAKRISHNAN DURAISAMY

TEXTILE TESTING LAB MANUAL

MSC CDF

Atmosphere 

Temperature – 25°C and Relative Humidity – 67%



Standard atmosphere: Temperature – 20°C and Relative Humidity - 65%.

Procedure 1. The specimen is cut by template and carefully creased by folding in half. 2. The crease is imparted on fabric by placing it between two glass plates and adding to 500gm weight on it. 3. After 1 min the weight is removed and the creased fabric is clamped on the instrument. 4. Then it is allowed to recover from the crease. The recovery time may vary to suit particular creases. Usually it is 1 min. 5. When crease recovers the dial of the instrument is rotated to keep the free edge of the specimen inline with the knife edge. 6. The recovery angle is read from the engraved scale. 7. In this way 10 tests are done in warp way and 10 for weft way. 8. The mean value of recovery angle is taken and thus crease recovery is measured. Tabulation Sl.No

Warp Recovery angle Average

Remarks

Weft Recovery angle

Remarks Average

1 2 3 4 5 Result Crease recovery is determined depending upon the recovery angle. If the angle is 0° then recovery is zero and if the angle is 180° then recovery is full. Here the recovery angle for the given fabric sample is the middle of the range. So it is to say that the crease recovery of the sample fabric is average. Crease recovery angle in warp way is ............0 ° Crease recovery angle in weft way is .............0 °

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10

GOPALAKRISHNAN DURAISAMY

TEXTILE TESTING LAB MANUAL

MSC CDF

Experiment - 5

Determination of Fabric Drape of the given fabric by drapemeter

Aim To find out the Drape of given fabric by the drapemeter. Method Fabric drape characteristics and behaviour are manifested in the appearance and fit of the garment and are usually assessed subjectively. Nevertheless, considerable research and development has been directed to the routine objective measurement and characterisation of drape and to relate drape, so measured, to objectively measured fabric mechanical properties, notably bending stiffness and shear stiffness. The following are some of the standard test methods used to measure fabric drape:     

BS 8357; BS 5058/EN 9073; UNI 8279; AFNOR G07-109; ERT 90-1.

Developed method of measuring drape by means of the F.R.L. Drapemeter, quantifying drape as a dimensionless drape coefficient (DC%). subsequently developed what has become known as drapemeter and which is still the standard and most common method of measuring drape. It has a parallel light source that causes the shape of the draped fabric to be projected onto a circular paper disc. The drape of a fabric is popularly defined as the area of the annular ring covered by the vertical projection of the draped fabric expressed as a percentage of the area of the flat annular ring of fabric, this being termed the ‘drape coefficient’. In practice, the contour of the shadow is often traced onto the paper and cut out for weighing. the drape coefficient (DC%) as the weight of the paper of the drape shadow (W2) expressed as a percentage of the paper weight (W1) of the area of the full annular ring; 

DC% = W2/W1 × 100 The drape geometry, i.e. the configuration of the draped sample, the drape measurement being employed to study the effects of fabric geometry.

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TEXTILE TESTING LAB MANUAL



MSC CDF

The drape diagrams, i.e. the projected 2D simplification of the 3D draped sample,

which contains three significant items:

 The area, which is the basis of the drape coefficient;

 the number of nodes – formed as a result of material buckling, the phenomenon of buckling, the type of load applications and the boundary conditions;

 the shape of the nodes – when the nodes are uniform, the drape diagram is a cyclic function in polar co-ordinates. Converting these polar coordinates into rectangular coordinates simplifies the analysis between the shape factor and the drape coefficient. Result Drape depended upon three basic fabric properties, namely Young’s modulus (Y), crosssectional moment of inertia (I) and fabric weight (W). [drape coefficient = f(B/W), where B = YI].

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GOPALAKRISHNAN DURAISAMY

TEXTILE TESTING LAB MANUAL

MSC CDF

Experiment - 6

Determination of bursting strength of the given fabric by Diaphragm of Bursting Tester

Aim To find out the bursting stregth of given fabric by the Diaphragm of bursting strength tester Method 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. Sampling Lot Sample As a lot sample for acceptance testing, take at random the number of rolls of fabric directed in an applicable material specification or other agreement between the purchaser and the supplier. Consider r...