It has indentations that look like occasional marks when viewed longitudinally. Nylon: There are many variants of nylon fiber. However, generally it appears fine, round, smooth and translucent. Sometimes it has shiny appearance. If it looks dull, it will also be dotted under the microscope. Aramid: If viewed longitudinally, aramid fiber looks smooth and straight. If viewed cross sectionally, it may be round or like peanut's shape. Polyester: Generally, polyester fiber is smooth, straight.
It looks round cross sectionally. However, with various finishing processes, its appearance changes in context of texture and luster. Spandex: Spandex fiber have the outstanding characteristic of appearing like groups of fibers fused together.
However, different variants of spandex show different characteristics too. The Lycra fiber looks like fused multifilaments cross sectionally. Individual fibers are dotted and in shape like that of dog-bone. If viewed longitudinally, they appear straight. Polypropylene: When viewed cross sectionally, polypropylene fiber looks somewhat round but it looks straight and smooth when viewed longitudinally. Glass: The glass fiber looks smooth, round, translucent, shiny and flexible.
It has harrow lumen running through centre. Cross sectional view : The cell wall appears thick and polygonal in shape.
Jute: Longitudinal View : Cross wise marks called nodes or joints. Cross sectional view : The fibres have a small central canal similar to the lumen in cotton. Several sided or polygonal with rounded edges.
Wool: Longitudinal View : Irregular and roughly cylindrical, prominent scale marking or flattened plates.. Cross sectional view : Oval to circular with variation in diameter medulla is concentric and variable in size.
Viscose: Longitudinal View : Uniform diameter with striation running parallel to the fibre axis. Cross sectional view : Differ in cross sectional appearance according to the process used. Basically has a irregular cross section. Polyester: Longitudinal View : Very regular, rod like appearance.
Cross sectional view : Circular in cross section. Nylon: Longitudinal View : Very regular, rod like appearance. Acrylic: Longitudinal View : Rod like with smooth surface and profile. Cross sectional view : Nearly round or bean shaped. There are two primary methods to conduct chemical testing- stain and solvent.
Stain Method: Stain technique uses acid and alkali on different fabrics to identify their fiber contents. Most of the fibers have two color reactions when treated with stain. A fiber stained with dilute acetic acid turns to a specific color.
The same fiber when stained with mild alkali like soda carbonate turns to a different color again specific to that fiber only. Acetate changes to light green color when acetic acid is used and turns orange when dilute carbonate of soda is used. Likewise, nylon turns beige in one and bright red in other.
As double testing is done in this method, it is sometimes referred to as double-barreled stain identification. Solvent Method: Various solvents are used in this method to distinguish one kind of fiber from another. However, there is no single solvent or chemical that can be used on all fibers. Additionally, different solvent procedures are adopted to separate and identify the fibers that are combined together.
It becomes very difficult to use solvent methods in view of fibers that have similar chemical characteristics. Also, when more fibers are mixed to produce blended fabric, then also it becomes tough to identify the fibers with the help of solvent method. However, it is a very effective method for cross checking but in order to have accurate reports, the fabric has to be cleaned thoroughly and the finishing chemicals should also be removed completely.
The fabric has to be unraveled, yarns have to be untwisted and the fibers have to be put in the solutions in as loose a condition as is possible. As an example of solvent method, consider differentiating animal fibers from plant fibers with alkali. If wool or silk fiber has to be eliminated from a blended fabric then strong alkalies can be used because animal particles are destroyed in it. Five percent of caustic soda or sodium hydroxide is used in water. The action of the chemical is hastened by boiling the solution before immersing the sample fabric in it.
The wool or silk fiber gets completely dissolved in it. The plant fibers remain unaffected. For differentiating them, acid has to be used as the dilute acids destroy plant fibers. A drop of sulfuric acid has to be put on the sample fabric which, in turn, is placed between two blotters and pressed with hot iron.
If it contains cotton, linen or rayon then the fabric gets charred at the spot. Sample Reference Identified fibre as Remarks 1. Preparation: Yarn Count: It indicates the weight per unit length or length per unit weight. In English system count denotes the number of hanks of yards that will weight one pound.
Lea: A continuous length of yarn in the form of a coil of 80 loops made on the reel of girth of 1. Sampling: Take 10 cops or 5 cones per sample. Automatic Wrap Reel: It is designed for preparing leas of yards of definite length with uniform tension, it helps in preparing more number of leas in short time.
Reel out the required length of yards for wrap reel. Cut and tie the trailing end of the lea to its leading end. Similarly take 30 leas making a total of 40 leas from the same 10 bobbins. Condition the sample in a conditioning box for about 12 hours. Say if there are bags, then select 5 bags randomly for testing. From each bag select one cone for testing and from each cone 10 tests are to be made thus total 50 testing.
The spring loaded jaws of the rotating clamp are opened and the clamp moved 1'' forward to touch the fixed clamp. For a longer test length say '' the sequence after a test is then: Slide the fixed clamp upto the rotating clamp, open the rotating clamp and allow the drum to take up the slack yarn, close it again, slide the fixed clamp back to its original position, close it and make the next test.
We will describe two methods which are applicable to the more common type of yarns - first for single yarn and the second for double or multi ply yarns. Twist tester for single yarn: We will describe a single yarn twist tester based on the twist contraction method.
After being led through the rotating jaw, the yarn is pulled through until the pointer lies opposite a zero line on a small quadrant scale; the jaw is then closed. As the twist is removed the specimen extends and the pointer assumes a vertical position. Eventually all the twist is taken out but the jaw is kept rotating in the same direction until sufficient twist has been inserted to bring the pointer back to zero mark again.
The total number of turns registered on the revolution counter is divided by two i. This gives the total twist in the yarn. To get the twist level per inch of the yarn, this number is again divided by ten.
Method This method is based on the fact that yarns contract in length as the level of twist is increased. Therefore if the twist is subsequently removed, the yarn will increase in length reaching a maximum when all the twist is removed.
The method uses a piece of equipment such as that shown in Fig. At the start of the test the yarn is placed under a suitable tension, either by a clip- onweight or by a weighted arm as shown. The test procedure is to untwist the yarn until all its twist has been removed and then to continue twisting the yarn in the same direction, until it Prepared by Prof.
The basis of the method is the assumption that the amount of twist put in is equal to the twist that has been removed. However, this is not necessarily the case. One source of error in the method is that at the point of total twist removal the fibres in the yarn are unsupported so that any tension in the yarn may cause the fibres to slip past one another, so increasing the length of the yarn. The difference in length if unnoticed will cause an error in the measurement of turns per unit length.
Another source of error is the fact that with some yarns, when the twist is removed, the amount of twist to bring it back to the same length is not equal to the twist taken out. Because of these problems the method is not recommended for determining the actual twist of a yarn but only for use as a production control method. There is a US standard for this method but it warns that the measured values are only an approximation of the true twist.
It suggests that 16 samples are tested using a gauge length of or mm. However, the method is easy to use and has less operator variability than the standard method so that it is often used for measuring the twist in single yarns.
Specimen preparation: Knitted fabric is made by loop formation. Some of the fabric properties depend on loop length. The method for measuring loop length of your sample.
To measure loop length of a knits fabric sample use following steps- Step 1: Take your sample and cut fabric swatch of 10 cm X 10 cm from the fabric sample. While cutting fabric swatch consider cutting on the wales line. Count number of wales in the 10 cm of fabric swatch. For example see the right side image, that has 6 wales.
Step 2: Take out yarns by pulling the loop. Don't consider yarns those are not full length of swatch. Take five yarns of complete length and stretch yarns to remove curling on yarns. Step 3: Measure yarn length. We Conduct Hands-on Workshops. There's An Instructional Video. This new EAA Sportair two-hour comprehensive video presents every aspect of our Poly-Fiber fabric covering process in detail and in easy-to-understand language.
From preparing the airplane for covering to spraying on the colors, you are guided step by step through the entire process by a professional EAA Sportair fabric instructor. Covers: preparing surfaces, attaching the fabric, tightening the fabric, applying the first coat of Poly-Brush, tying rib-lacing knots, applying finishing tapes, spraying Poly-Spray, applying color coats.
You Always Have Worldwide Availability. Our network of distributors covers the US, Canada, and much of the world. Turn the power on. The machine should already be programmed to run a batch of movements. 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. Put specimens back on the machine and continue with the test.
Observe and record the results after each batch of movements until you have Reached the desired number of movements total of Tabulation Sample wt. Remark It is easily understood that the more is no. 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 D and the specimens were tested as directed in Test Method D 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. 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. Procedure 1. The specimen is cut by template and carefully creased by folding in half.
The crease is imparted on fabric by placing it between two glass plates and adding to gm weight on it. After 1 min the weight is removed and the creased fabric is clamped on the instrument. Then it is allowed to recover from the crease. The recovery time may vary to suit particular creases. Usually it is 1 min. When crease recovers the dial of the instrument is rotated to keep the free edge of the specimen inline with the knife edge.
The recovery angle is read from the engraved scale. In this way 10 tests are done in warp way and 10 for weft way. The mean value of recovery angle is taken and thus crease recovery is measured.
Tabulation Sl. 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 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.
Developed method of measuring drape by means of the F. It has a parallel light source that causes the shape of the draped fabric to be projected onto a circular paper disc. In practice, the contour of the shadow is often traced onto the paper and cut out for weighing. Converting these polar coordinates into rectangular co- ordinates simplifies the analysis between the shape factor and the drape coefficient. 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 rolls of fabric to be the primary sampling units. Laboratory Sample As a laboratory sample for acceptance testing, take a full width swatch 1 m 1 yd long from the end of each roll of fabric in the lot sample, after first discarding a minimum of 1 m 1 yd of fabric from the very outside of the roll. From each roll or piece of circular knit fabric selected from the lot sample, cut a band at least mm 1 ft wide. Test Specimens Cut ten test specimens from each swatch in the laboratory sample with each specimen being.
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 mm 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. 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. Hand Driven Tester 1. Insert the conditioned specimen under the tripod, drawing the specimen taut across the plate, and clamp specimen in place by bringing the clamping lever as far to the right as possible.
Rotate the hand wheel, clockwise at a uniform speed of rpm until the specimen bursts. Stop turning the hand wheel at the instant of rupture of the specimen. Immediately after rupture and in rapid succession, release the clamping lever over the specimen. Immediately release the strain on the diaphragm by turning the wheel counterclockwise to its starting position and record the pressure required to inflate the diaphragm tare pressure.
Record the total pressure required to rupture the specimen. Motor-Driven Tester 1. Inflate the diaphragm by moving the operating handle to the left. While the diaphragm is inflating, take hold of the latch that is located below, or to the right, of the operating 4. At the instant of rupture of the specimen, swing the latch as far as it will go to bring the operating handle to an idling neutral position.
Immediately after rupture, and in rapid succession, release the clamping lever over the specimen. Method Crockmeter In order to determine the color fastness of dyed or printed textiles or leather, this test is used for the determination of color fastness against rubbing, either under dry or under wet conditions.
Features of Crockmeter 1. To determine the Color Fastness of Textiles. The equipment consists of a counter. It is provided with a flat peg.
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