Textile Testing Instruments for Yarn, Fabric and Garments
Shareful Islam Palash
Lecturer, Institute of Textile Engineering & Information Technology
There are many types of textile testing instruments. Those are used for different way and different process in textile sector. Here given some of textile testing Instruments, which are used for yarn, fabrics and garments testing process.
1. Yarn Testing Instruments:
a. Crimp Rigidity Tester:
Crimp is an important property that determines processing behavior in carding, drafting and fault incidences in yarn. Crimp frequency, amplitude, crimp stability, crimp elongation, decrimping point are some of the important properties that determine crimp.
Crimp Rigidity Tester is used to determine the bulking potential of texturized yarns.
Crimp Rigidity Tester can be used for both polyamide and polyester texturized yarns. Crimp frequency and amplitude may be determined by projecting a magnified image of fiber on screen.
Feature of Crimp Rigidity Tester
- The instrument is based on test method.
- The tester can be used for both polyamide and polyester texturized yarns.
- Instrument mounted on a sturdy metal base. Compact and portable.
- Heating arrangement for measurement of hot Crimp contraction.
How Crimp Rigidity Tester works?
The principle of this test is as follows:
A load equivalent to 0.09 g/dtex is suspended from the end of a yarn immersed in water. After a fixed time, the load is reduced to 0.0018 g/dtex and after a further fixed time the reduction in the length of yarn is measured. The crimp rigidity of yarn is the reduction in length of the yarn expressed as a percentage of the original length.
The test method used was as follows:
- Place the package of yarn to be tested on the stud of the base plate of the hank winder in the apparatus below the yarn guide.
- Thread the yarn through the gate tensioner and adjust the tension until, on pulling the yarn through the gate; it can be observed that the crimp is getting removed.
- Clamp the leading end of the yarn to the inner side of the capstan. Wind a hank of yarn with a number of strands chosen so that loads of 0.09 g/dtex and 0.0018 g/dtex can be applied to each strand by means of the sets of hooked weights provided. (The loads and No. of strands for yarns most commonly encountered are listed in the Table given in BIS Handbook.) Clamp the final strand to the outside of the capstan.
- Add appropriate lightweight to the strands extending across the prongs of the fork at the lower end of the arm of the hank winder. Add appropriate heavy weight to the lower hook of the lightweight.
- Remove the hank and the suspended weight by unscrewing the hank bar from the arm of the winder.
- Attach the extra clip support to the hank bar and immerse the hank in the water contained in the measuring cylinder by clipping the two supports over the rim of the cylinder.
- Start the stop watch.
- Just prior to 2 min from immersing the hank, measure the length of hank as L0.
- At 2 min from the time of immersion remove the heavy weight by raising the grid, causing the weight to be released from S-shaped hook.
- After a further 2 min. measure the length of hank as Ls.
Crimp Rigidity = L0 – Ls / L0 x 100
b. Yarn Appearance Board Winder:
Yarn Appearance Board Winder is used to compare the appearance of irregularities against standard rating photographs which carry out visual determination of unevenness along the length of a yarn. Tenable yarns of different thickness to be assessed; the spacing between the wraps is suitably selected so as to clearly give a distinguishable pattern.
Yarn Appearance Board Winder is used for wrapping the yarn in equally spaced parallel wraps over a board for visual examination.
Features of Yarn Appearance Board Winder:
- Manually operated.
- Checks the evenness & appearance of yarn.
- Precise preparation for accurate assessment of imperfection to grade the yarn against photographic comparison standards.
- Is used for winding the yarn on the blackboard for visual examination and grading the yarn as per ASTM standards.
- Choices of wide range of rectangular and tapered boards.
How Yarn Appearance Board Winder Works?
- Yarn number of the yarn to be tested has to be determined. The appropriate spacing of the yarn wraps on the boards has to be found from the table.
- A parallel/tapered board has to be fixed onto the short stubs.
- The spacing of the yarn on the board has to be checked by making a small sample wrapping on it.
- The moving block has to be raised. It is taken to the right side and released. The yarn guide fixed on this block has to be in alignment with the point from where the winding will start. To ensure this, a red mark is present on the guide road.
- The bobbin containing the yarn to be tested has to be placed on the stand. The yarn has to be passed through the tensioning device and the eyes on the front bracket and moving block.
- The tension on the yarns has to be adjusted so that it moves freely onto the board as it is rotated. Wrap the yarn over the board till a sufficiently wide band is formed.
- Cut off the yarn and remove the board from the apparatus.
- Evaluating the evenness rating of the yarn by comparing the board against the master photographs of the same spacing. The standard has 4 master photographs: A, B, C, and D in each spacing.
- Comparing the specimen with the different ASTM Cotton Yarn Appearance Standards.
- Assigning to the specimen the grade designated for the photograph for which it is equal to or better than, without being equal to the next higher grade.
2. Fabric & Garments Testing Instruments:
a. GSM Cutters:
GSM cutters are used to determine accurately the GSM (Grams per square meter) of any type of fabrics. This GSM Cutter is circular fabric sample cutter with which uniform circular fabric is cut without measuring. The specimen which is cut with the help of fabric GSM cutter is 100 cm2 areas. The instrument is equipped with a set of four replaceable blades and normal cutting pads.
Accessory of GSM Cutter:
- GSM Pad
- GSM Weighing Scale
Features of GSM Cutter:
- Reliable rapid, and easy to use.
- 100 Square Centimetres cutting area.
- Depth of cutting up to 5mm.
- Special finishes for contacting surfaces to avoid of specimen slippage.
How GSM Cutter works?
The material to be cut is placed between the Sample Cutter and a Special Cutting Board. When the safety catch is released, light downward pressure on the hand wheel brings the multiple blades into contact with the material. Specimens are cut by rotating the hand wheel under a light and even pressure. The design and precision manufacture of the instrument ensures the specimens are perfectly circular and have smooth edges. To maintain the cutting efficiency, the blades should be turned or changed when they become damaged or blunt, and the Cutting Board should be turned or changed when it becomes worn.
Applications of GSM Cutter:
GSM cutter are not just use in textile industry, they are use in various other industries like acrylic sheets, aluminium and foils, bags and luggage of cotton, plastic, paper and leather, beach wear, blankets, belts, foot ware, paper industry, package material, machines, boxes, polyester & BOPP films, hand tuffed carpets, home furnishing items Teflon products, thermal paper & thermocol and various other endless things.
b. Digital Fabric Testing Instrument:
Digital Fabric Testing Instrument determines the thickness of jari, yarn, fabric, paper, and film samples etc. accurately. In Digital Fabric Thickness Gauge, the fabric whose thickness is to be determined is kept on a flat anvil and a circular pressure foot is pressed on to it from the top under a standard fixed load.
Features of Digital Fabric Thickness Gauge:
- Determines the thickness of yarns, fabrics, paper, etc.
- Range of measurement: 0 – 10 mm.
- Thickness is accurately measured in millimeter through digital gauge.
- Standard load on the pressure foot to ensure accuracy.
- Supplied with calibration & inspection certificates.
- Accurately and conveniently performs thickness measurement.
- Consists of a dial micrometer with a flat pressure foot and a flat anvil.
How Digital Fabric Thickness Gauge Works?
- The fabric sample that is to be measured is kept on an anvil.
- The press foot is gently lowered on to the specimen.
- The reading is taken to get the thickness of the specimen.
- The flat circular indenter of the micrometer exerts the specified pressure on the fabric sample.
- The above procedure is repeated to obtain the values of thickness at least at 3 different locations.
- The mean value of all the readings of thickness determined to the nearest 0.01m is calculated and the result is the average thickness of the sample under test.
c. Martindale Abrasion cum Pilling Tester:
Martindale Abrasion cum Pilling Tester is used to check the abrasion as well as pilling resistance of the fabric. It consists of four testing plates on which the abrading fabrics is attached, these four-testing table are mounted on the base plate of the instrument. There is revolving plate, which revolves with the help of three cranks, pegs & motor.
There are four sleeves attached on the revolving plate. The sample holders for abrasion & pilling testing are provided with the instrument. There is a set of weights for proper pressure on the test specimens. Templates for cutting the samples & abrading cloth and their mallet are also supplied as standard accessory.
Features of Martindale Abrasion cum Pilling Tester:
- Effective speed ratio of outer pegs to inner pegs
- 4 specimens can be tested simultaneously.
- Maximum load (corresponding to pressure of 12KN/m2): 790g
- Comprise of stainless-steel balls.
- Acrylic Top Plate for safety.
- The Abrasion of the fabric can be tested through two methods.
How Martindale Abrasion cum Pilling Tester works?
Number of rubs to end point:
- 4 specimens of each sample can be tested in each of the specimen holder of the machine.
- Inspect the specimens without removing them from the holders at regular intervals and note the number of rubs when at least two threads are broken.
- This should be assessed independently for each specimen and the specimens removed when they reach end point.
Average weight loss
- Abrade two specimens to end points as in above case and then abrade further pairs of specimens.
- Weight all the specimens before and after abrasion and plot a graph of weight loss against the number of rubs.
- Draw a line through the points and determine the rate of weight loss in mg per 1000 rubs if reasonably linear.
- The degree of pill formation can be visually assessed by the set of photographic rating standards available for comparing the tested specimen.
d. Stiffness Tester:
Stiffness Tester is used to determine the stiffness of fabrics.
Stiffness Tester provides a quick and accurate method of determining stiffness properties such as flexural rigidity of most textile fabrics and other flexible materials. The principle of Cantilever Test method is used in it.
Features of Stiffness Tester:
- It has a solid aluminium base with nylon foot-rest to keep the base horizontal.
- The equipment’s parts are made of stainless steel.
- It has a calibrated scale.
How Stiffness Tester works?
- The Stiffness Tester is placed on a level surface and the levels are checked with the help of the sprit level.
- The fabric specimen has to be cut into a size of 150 x 25 mm, with the help of Acrylic Specimen Preparing Template.
- The test specimen has to be placed flat on the platform of the instrument.
- The calibrated scale is gently put on the fabric.
- The marking on the acrylic plate of the Stiffness Tester has to be viewed in the mirror.
- The scale has to be then gently slided till the leading edges of the test specimen moves away from the scale and bends down till it touches the two inclined lines.
- In case the leading edge is twisted, make the centre point of the leading edge coincide with the plane. If the twist is more than 45° disregard the reading.
- The reading on the scale is noted down.
- The test has to be repeated 4 times and the average bending length has to be determined.
- All the test samples have to be weighed and their length and width has to be measured and then their areas have to be calculated and weight per unit area determined.
- Flexural rigidity and Bending modulus are then calculated using the appropriate formula.
e. Water Repellency Tester:
Water Repellency Tester measures the resistance of fabrics to wetting by water.
Water Repellency Tester is used to check the water repellency of the fabric by spray test in textile testing laboratory. Suitable for Table cloth, tapestry, flooring material fabric manufacturer or processors.
Features of Water Repellency Tester:
- The tester is suitable for measuring the water-repellent efficiency of finishes applied to fabrics, particularly plain-woven fabrics.
- Evaluation is accomplished by comparing the wetted pattern with pictures on a standard chart.
How Water Repellency Tester Works?
- Before testing is carried out the specimen shall be conditioned for at least 24 hours in the standard atmosphere. Water sprayed against the taut surface of a test specimen under controlled conditions produces a wetted pattern whose size depends on the relative repellency of the fabric.
- To carry out the test, first of all fasten the test specimens securely in the metal hoop of the water repellency tester so that it represents a smooth wrinkle free surface and place it face up on the tester.
- Adjust the metal hoop so that the center of the spray coincides with the center of the metal hoop. Later pour 250 ml of distilled water at normal temperature into the funnel and spray the whole quantity on the test specimen for a period of 25 – 30 sec.
- Now detach the metal hoop from the stand. Confirm whether water had penetrated to the back of the test specimen. With the face side of the test specimen down, hold the metal hoop by one edge and tap the opposite edge lightly once against the table.
- Then rotate it 180°C and similarly tap again once on the point previously held to remove any excess water drop.
- The final step is to compare the wetting of the test specimen with a photographic rating standard and grade it accordingly.
f. Water Impact Penetration Tester:
Water Impact Penetration Tester tests water penetration resistance of the garment fabrics.
Its aim is to test the water absorbency –resistance degree for Waterproof fabric or other material. It is a standard procedure for determining the resistance to water penetration under uniform static air pressure differences. The instrument can be switched between high pressure and low pressure.
Features of Water Penetration Tester:
- Equipment is portable.
- Very convenient to use.
- White AATCC textile blotting paper is used for testing.
- Ensures accurate results.
How Water Penetration Tester works?
- Clamp one end of the specimen under 152mm spring clamp at the top of the inclined stand.
- A standard blotter paper 152 x 230 mm is weighed to the nearest 0.1g and inserted beneath the test specimen.
- Pour the distilled water into the funnel of tester and allow spraying onto the test specimen.
- The water should be poured into the funnel without imparting any swirling motion of the water in the funnel.
- Upon completion of the spraying period, the test specimen is carefully lifted, the blotter beneath removed, and then quickly reweighed to the nearest 0.1 g.
g. Shrinkage Template & Scale:
Shrinkage Template & Scale is used for finding accurate Shrinkage in fabric and Garments. Shrinkage Template & Scale also measures the dimensional changes in fabrics after laundering, dry cleaning etc.
Features of Shrinkage Template & Scale:
- To determine directly the % dimensional change (shrinkage) in all types of fabrics.
- Fine calibrated Shrinkage Template with 18″ x 18″ & 10″ x 10″ benchmarks length-wise & width-wise.
- Calibrated scale to evaluate shrinkage & stretch directly Up to 15%.
- Two fine tipped black & yellow fabric markers are supplied for accurate marking on light & dark colour fabrics.
How Shrinkage Template & Scale works?
- The marking template should be placed on the specimen to be tested, making sure that the fabric is in flat position before marking.
- Hold the template firm, and carefully mark the fabric through the eight slots of the template, to ensure that it does not move.
- Now put the fabric in the washing machine or Dry Cleaning.
- Dry the sample as per any of the method. It can either be Line Dry or Flat Dry or Tumble Dry.
- To find the dimensional change read the Shrinkage/Stretch on 3 points on the Wrap side and 3 points on Weft Side.
- Get the mean value of wrap-wise and weft wise readings to get the Accurate Shrinkage or Stretch.
h. Digital Pilling Tester:
Digital Pilling Tester is used to check the pilling resistance of the fabric.
Pilling is a fabric surface fault characterized by little pills of entangled fibers clinging to the surface. Pills are formed during wearing or washing by the entanglement of the loose fibers, which protrude from fabric surface. To determine the tendency to form pills, test specimens taken from the fabric sample are rubbed against each other under controlled conditions.
Features of Digital Pilling Tester:
- Consists of two wooden cubical Boxes with inside surfaces lined with special standard cork sheet and outside surfaces beautifully laminated.
- Consists of geared motor which rotates the boxes about their central axis.
- Pre-set Digital Counter stops the motor automatically after the desired number of revolutions.
- Can be used for all types of fabric and weave patterns.
- Eliminates subjective assessment.
- More accurate.
- User friendly.
- Adopted universal standard testing procedure.
How Digital Pilling Tester works?
- The very first step is to clean the boxes thoroughly.
- Then place four mounted test specimens in each box and close the boxes.
- Later set the pre-set counter at 18000 with the help of the Thumb Wheel setting provided on the Digital Counter.
- Press the start button. The machine would stop automatically after 18000 revolutions.
- Now, finally take the specimens and compare them with the photographic rating standards.
i. Crease Recovery Tester:
Crease Recovery Tester determines the property of textiles to recover from creases by measurement of the recovery angle. The specimen is first creased under specified load for fixed time and is then transferred to the measurement device, where one end of the specimen is held in a spring-loaded clamp and other is allowed to fall free under its own weight. Now one need to read the scale fixed to moving clamp to know the deflection of the clamped end from the horizontal. This angle gives the measure of the Crease Recovery.
Features of Crease Recovery Tester:
- Made of heavy caste base with all parts of stainless steel
- Imported Acrylic Sheet used for making the Rotating Dial.
- To make the movement smooth the Dial moves in a Brass bush.
- The same base has both the Steel Creasing Load and two Round Steel Plates for pressing the specimen.
How Crease Recovery Tester works?
- Fold the specimen and if the surfaces of the specimen have a tendency to stick together, place a piece of paper or aluminium foil, between the ends of specimen.
- Place the folded specimen between the two leaves of the loading device and immediately apply the weight.
- Start timing device, and after 5mins quickly but smoothly remove the weight from the first specimen.
- Using tweezers transfer the folded specimen to the instrument’s circular specimen holder. Insert one end of the specimen between the clamps on the specimen holder, leaving the other end to hang freely.
- While the specimen is in the holder, adjust the instrument to keep the free hanging end of the alignment with the vertical mark.
- Finally, read and record the recovery angle from the circular scale 5 minutes after inserting the specimen into the clamp.
You may also like:
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- How to Calculate GSM of Woven and Knitted Fabric
- Classification of Textile Testing: Fiber Testing, Yarn Testing, Fabric Testing
- Reasons for Textile Testing and Different Fabric Test
- List of Basic Tests of Textile Fabric
- Determination of Fabric Crease Recovery by Shirley Crease Recovery Tester
- Determination of Fabric Abrasion Resistance by Abrasion Resistance Tester
- How to Determine Carpet Thickness by Shirley Thickness Tester
- Determination of Crimp Percentage of Woven Fabric
- Determine Stiffness of the Fabric by Shirley Stiffness Tester
- Different Types of Textile Testing Methods
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Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.