Repellency Of Textile PDF

REPELLENCY OF TEXTILE NED University Of Engineering & 2 Technology  IMPORTANCE OF WATER REPELELNCY IN TEXTILE Water repellency is one of the most common functional properties that is needed for protective clothing without af...

REPELLENCY OF TEXTILE NED University Of Engineering & 2 Technology  IMPORTANCE OF WATER REPELELNCY IN TEXTILE Water repellency is one of the most common functional properties that is needed for protective clothing without affecting the comfort ability. Water repellency is defined as the ability of a textile material to resist wetting. Water repellent textiles have many uses including industrial, consumer and apparel purpose NED University Of Engineering & 3 Technology  IMPORTANCE OF WATER REPELELNCY IN TEXTILE Water repellency treatment modifies the surface tension properties of fibers or fabrics so that they repel water drops. The treatment may also improve soil repellency. Water resistance is needed in outdoor clothing for protection against rain and is a requirement for furniture and bed-coverings to protect against liquid excretions NED University Of Engineering & 4 Technology  SOME DEFINITIONS Water resistance The characteristic to resist water repellent wetting and penetration by Water proof water. (See also water It is the relative degree of repellency.) resistance of a fabric to surface wetting, water penetration, Condition where a textile water absorption or any material (treated or untreated) combination of these can prevent the absorption of properties but its assessment water & also the penetration is dependent upon objective of water in to its surface. Thus &/or subjective factors a water proof surface provides appertaining to the test a barrier to water under all condition practical end use condition NED University Of Engineering & 5 Technology DIFFERENCE BETWEEN WATER REPELLENT AND WATER PROOF TEXTILE? Water repellent Water Proof Pores open Filled Water vapor permeability Small to large Zero to very small Air permeability Usually large Zero to small Resistance to wetting by rain drops & spreading & wicking of Resistance to water water. Permits water passage Highly resistant even under penetrations external hydrostatic pressure under external hydrostatic pressure NED University Of Engineering & 6 Technology  SOME DEFINITIONS WETTING WICKING Wetting is the displacement of a fiber-air interface with a LOW ENERGY SURFACE fiber-liquid interface Wicking is the spontaneous flow of a liquid in a porous substrate, driven by capillary Surfaces that exhibit low forces. Because capillary interactions with liquids forces are caused by are called as low energy wetting, wicking is a result surfaces of spontaneous wetting in a capillary system NED University Of Engineering & 7 Technology  SOME DEFINITIONS SURFACE TENSION Surface tension is the cohesive SURFACE ENERGY force of molecules at the surface of an element attracting toward performed on solids at the CONTACT ANGLE one another to take up the least solid-gas interface, provides possible surface area. In even Contact angle is measured as information about solid simpler terms, it measures how the angle where a liquid or a much force it takes to keep a wettability, in particular is an liquid together. expression of hydrophylicity, vapor (but most often a hydrophobicity and liquid) interacts with a solid Expressed as mN/m. surface olephobicity behaviors Expressed as mN/m. Fabric to be water repellent it surface tension of the liquid must Fabric to be oil repellent be 73mN/m it surface tension of the liquid must be 20-35 mN/m NED University Of Engineering & 8 Technology  COMMON FINISHES FOR REPELLENCY PARAFFIN REPELLENT STEARIC ACID ( melamine repellent SILICON WATER REPELELNT Produces surfaces FLUROCARBON BASED REPELLENT having surface energy 15-20mN/m NED University Of Engineering & 11 Technology Typical Textile & Their Requirement for Repellency Finishes NED University Of Engineering & 12 Technology FACTORS AFFECTING THE REPELLENCY OF TEXTILES FIBRE CHEMICAL FABRICS FINISHES NED University Of Engineering & 13 Technology  TEST METHODS FOR WATER REPELLENCY Class I Spray test to simulate exposure to rain (AATCC 22,35,42) Hydrostatic pressure tests. These measure Class II the water penetration as function of pressure exerted by water standing on the fabric. AATCC 127, ISO 811) Class III Sorption of water by the fabric immersed in water. AATCC 70 NED University Of Engineering & 14 Technology  OIL REPELELNT (HYDROCARBON RESISTANT TEST) AATCC 118 NED University Of Engineering & 2 Technology  scope This test method is used to detect the presence of a fluorochemical finish, or other compounds capable of imparting a low energy surface, on all types of fabrics, by evaluating the fabric’s resistance to wetting by a selected series of liquid hydrocarbons of different surface tensions NED University Of Engineering & 3 Technology  STANDARD TEST LIQUIDS AATCC OIL REPELLENCY Drops of standard test liquids, consisting of a selected series of hydrocarbons with varying surface tensions, are placed on the fabric surface and observed for wetting, wicking and contact angle. The oil repellency grade is the highest numbered test liquid which does not wet the fabric surface NED University Of Engineering & 4 Technology  TEST SPECIMEN SIZE AND PREPERATION Test two specimens of the same size from each sample. Specimen size should be sufficient to allow for the complete range of test liquids to be evaluated, but shall be no smaller than 20 × 20 cm.. Condition the test specimens for a minimum of 4 h at 21 ± 1°C (70 ± 2°F) and 65 ± 2% RH prior to application of stains NED University Of Engineering & 5 Technology  TESTING FOR HYDROCARBON RESISTANT TEST TESTING CAN BE CARRIED OUT AT; 1. As Received 2. After The Number Of Washes As Agreed IF, TEST NEED TO BE DONE AFTER WASHING , THEN WASH AS PER THE PROCEDURE DESCRIBED IN AATCC 135 (AS PER CARE LABEL FOR WASHING AND DRYING) NED University Of Engineering & 6 Technology  TEST PROCEDURE Place the test specimen flat on the white textile blotting paper on a smooth, horizontal surface. When evaluating open weave of “thin” fabrics, conduct the test on at least two layers of the fabric; otherwise, the test liquid may wet the underlying surface, not the actual test fabric, and thereby cause confusion in the reading of the results. Equipment, benches and gloves must be free of silicone. Use of silicone containing products could adversely affect the oil repellency grade. NED University Of Engineering & 7 Technology  TEST PROCEDURE Wearing clean laboratory gloves, brush the pile of napped or pile fabrics with your hand in the direction giving the greatest lay of the surface prior to placing the drops of the test liquid Beginning with the lowest-numbered test liquid (AATCC Oil Test Grade Liquid No. 1), NED University Of Engineering & 8 Technology  TEST PROCEDURE carefully place small drops [approximately 5 mm (0.187 in.) in diameter or 0.05 mL volume] on the test specimen in five locations along the filling direction. The drops should be approximately 4.0 cm (1.5 in.) apart. The dropper tip should be held at a height of approximately 0.6 cm (0.25 in.) from the fabric surface while placing drops. DONOT TOUCH THE FABRIC WITH THE DROPPER TIP NED University Of Engineering & 9 Technology  TEST PROCEDURE Observe the drops for 30 ± 2 s, from approximately a 45° angle. If no penetration or wetting of the fabric at the liquid-fabric interface and no wicking around the drops occur, place drops of the next higher-numbered test liquid at an adjacent site on the fabric and again observe for 30 ± 2 s. Continue this procedure until one of the test liquids shows obvious wetting or wicking of the fabric under or around the drop within 30 ± 2 s. NED University Of Engineering & 10 Technology  GRADING OF THE DROPS A = Passes; clear well- rounded drop B = Borderline pass; rounding drop with partial darkening C = Fails; wicking apparent and/or complete wetting D = Fails; complete wetting NOTE: A borderline pass occurs if three (or more) of the five drops applied show the rounded drop with partial darkening of the test specimen (Fig.1 [B]). The grade is expressed to the nearest 0.5 value determined by subtracting one-half from the number of the borderline pass test liquid. NED University Of Engineering & 11 Technology  GENERAL REQUIREMENTS Grade 7 to 7.5 ORIGINAL STATE AFTER AS AGREED AGREED NO. BTWEEN THE OF WASHES PARTIES NED University Of Engineering & 12 Technology SOIL AND STAIN RELEASE TEST AATCC 130 NED University Of Engineering & 13 Technology  SOME TERMINOLOGIES , dirt, oil or other the degree to a local deposit of STAIN SOIL SOIL RELEASE substances not which a soiled soil or normally intended substrate discoloration on a to be present on a approaches its substrate that substrate such as original, unsoiled exhibits a textile material. appearance as a some degree of result of a care resistance to procedure removal, as by laundering or drycleaning NED University Of Engineering & 14 Technology  PRINCIPAL An amount of the staining substance is forced into the fabric by using a specified weight. The stained fabric is then laundered in a prescribed manner and the residual stain rated on a scale from 5 to 1 by comparison with a stain release replica showing a graduated series of stains NED University Of Engineering & 15 Technology  TEST SPECIMEN SIZE AND PREPERATION Use two test specimens 38 × 38 ± 1 cm (15.0 × 15.0 ± 0.4 in.) Condition the test specimens for a minimum of 4 h at 21 ± 1°C (70 ± 2°F) and 65 ± 2% RH prior to application of stains NED University Of Engineering & 16 Technology  TESTING FOR STAIN RELEASE TESTING IS REQUIRED TO BE CARRIED OUT AT; 1. original state (after one wash) 2. after three wash or number of washes as agreed IF, TEST NEED TO BE DONE AFTER WASHING , THEN WASH AS PER THE PROCEDURE DESCRIBED IN AATCC 135 (AS PER CARE LABEL FOR WASHING AND DRYING) NED University Of Engineering & 17 Technology  STAINING PROCEDURE 1. Place the unstained specimen flat on a single thickness of AATCC White Textile Blotting Paper on a smooth, horizontal surface. 2. Using the medicine dropper, place 5 drops (approx. 0.2 mL) of corn oil in the approximate center of the test specimen. 3. Place a 7.6 × 7.6 cm (3.0 × 3.0 in.) square of glassine paper over the stained area. 4. Place the weight 5 lbs on the glassine paper directly over the stained area. 5. Allow weight to sit for 60 ± 5 s. Then remove the weight and discard the glassine sheet. 6. Do not allow stained test specimens to contact each other in a manner which would transfer stains. Wash within 20 ± 5 min after staining NED University Of Engineering & 18 Technology NED University Of Engineering & 19 Technology  SPECIMEN 01 SPECIMEN 02 01 02 STAIN NED University Of Engineering & 20 Technology  WASHING CONDITIONS Machine Cycle Washing Temperatures 1. Normal/Cotton Sturdy II. 80 ± 5F (27 ± 3C) 2. Delicate III. 105 ± 5F (41 ± 3C) 3. Permanent Press IV. 120 ± 5F (49 ± 3C) V. 140 ± 5F (60 ± 3C) NED University Of Engineering & 21 Technology  DRYING CONDITIONS A. Tumble i. Cotton Sturdy ii. Delicate iii. Permanent Press B. Line C. Drip D. Screen NED University Of Engineering & 22 Technology  PROCEDURE Select washing conditions and settings; allow machine to fill with water Add 66 gm of 1993 AATCC Standard Reference Detergent Add test specimens and ballast Set cycle and wash; rinse at  85F Select Washing temperature as per care label Select drying conditions and dry per care label NED University Of Engineering & 23 Technology  EVALUATION 1. Mount the stain release replica on the mounting board, with the center of the standard 114 ± 3 cm (45 ± 1 in.) from the floor. 2. Place the test specimen flat with face up in the center of the non-glare black topped table with one edge of the table touching the mounting board. The fabric shall be rotated to be viewed from the direction which produces the lowest rating. 3. Viewing distance shall be 76 ± 3 cm (30 ± 1 in.) from the back mounting board, with the eye at 157 ± 15 cm (62 ± 6 in.) from the floor. The rater should stand directly in front of the specimen. Varying the viewing angle either horizontally or vertically can affect grades obtained on some fabrics. 4. Each rater shall independently compare the residual stain on the test specimen 5. with the stains on the stain release replica and rate each test specimen to the nearest 0.5 grade according to Table II. NED University Of Engineering & 24 Technology  EVALUATION Grade 5 — Stain equivalent to Standard Stain 5 (Negligible or no staining) Grade 4 — Stain equivalent to Standard Stain 4 (slightly stained) Grade 3 — Stain equivalent to Standard Stain 3 (Noticeably stained) Grade 2 — Stain equivalent to Standard Stain 2 (Considerably stained) Grade 1 — Stain equivalent STAIN RELEASE REPLICAS FOR AATCC 130 to Standard Stain 1 (Heavily stained) NED University Of Engineering & 25 Technology  ASSESSMENT FOR STAIN RELEASE DARK ROOM F96 CW (cool white) NED University Of Engineering & 26 Technology GENERAL REQUIREMENTS ORIGINAL Grade 4 to STATE 4.5 AFTER Grade 3 THREE WASHES NED University Of Engineering & 27 Technology  Spray test to simulate exposure to rain AATCC 22 NED University Of Engineering & 2 Technology  SCOPE This test method is applicable to any textile fabric, which may or may not have been given a water-repellent finish. It measures the resistance of fabrics to wetting by water. It is especially suitable for measuring the water- repellent efficacy of finishes applied to fabrics. The results obtained with this test method depend on the resistance to wetting or water repellency of the fibers, yarns and finishes on the fabric, and upon the construction of the fabric NED University Of Engineering & 3 Technology  APPARATUS AND MATERIALS AATCC Spray Tester Graduated cylinder, 250 ml. distilled Water, Standards spray test rating (Photographic) Chemical for water repellent finish Fabric to be tested NED University Of Engineering & 4 Technology SPRAY TESTER NED University Of Engineering & 5 Technology  TESTING FOR SPRAY TEST TESTING CAN BE CARRIED OUT AT; 1. As Received 2. After The Number Of Washes As Agreed IF, TEST NEED TO BE DONE AFTER WASHING , THEN WASH AS PER THE PROCEDURE DESCRIBED IN AATCC 135 (AS PER CARE LABEL FOR WASHING AND DRYING) NED University Of Engineering & 6 Technology  TEST SPECIMEN SIZE AND PREPERATION Two Specimens size 180.0 × 180.0 mm (7.0 × 7.0 in.) are needed. Where possible, each specimen should contain different groups of lengthwise and widthwise yarns Condition the test specimens for a minimum of 4 h at 21 ± 1°C (70 ± 2°F) and 65 ± 2% RH prior to test NED University Of Engineering & 7 Technology  TEST PROCEDURE The test cab be done on finished and unfinished fabric. If it is required to finish then, Cut a sufficient piece of fabric in order to apply the water repellent finish. The water repellent finished fabric is then cut as per the sample size stated above for testing and conditioned it. Calibrate the apparatus by pouring 250 mL of distilled water at 27 ± 1°C (80± 2°F) into the funnel of the tester and measure the time required for the funnel to empty. The spray time must be between 25-30 s, otherwise the nozzle should be checked to see if the holes are enlarged or blocked. NED University Of Engineering & 8 Technology  TEST PROCEDURE Fasten the test specimen securely in the 152.4 mm (6.0 in.) diameter hoop so that the face of the fabric specimen will be exposed to the water spray. The surface of the specimen should be smooth and without wrinkles. Place the hoop on the stand of the tester with the fabric uppermost in such a position that the center of the spray pattern coincides with the center of the hoop. In the case of twills OR fabrics with similar ribbed construction, place the hoop on the stand in such a way that the fabric is oriented in the same direction as it will be used in the end product. NED University Of Engineering & 9 Technology  TEST PROCEDURE Pour 250 mL of distilled water at 27 ± 1°C (80 ± 2°F) into the funnel of the tester and allow it to spray onto the test specimen for 25-30 s. Avoid touching the funnel with the graduated cylinder while pouring the distilled water. Movement of the funnel will alter the spray disposition on the specimen. Take the hoop by the bottom edge and tap the opposite edge firmly once against a solid object with the fabric facing the object, then rotate the hoop 180° and tap once more on the point NED University Of Engineering & 10 Technology TEST PROCEDURE NED University Of Engineering & 11 Technology  EVALUAION Immediately after tapping, compare the wet or spotted pattern with the rating chart Rate the face of the specimen. Each test specimen is assigned a rating corresponding to the nearest level on the rating chart. Intermediate ratings can be used for ratings of 50 or higher (95, 85, 75, 60). In rating loosely woven or porous fabrics, such as voile, any passage of water through the openings of the fabric is disregarded. Report the individual rating results for each test specimen. Do not average the results. NED University Of Engineering & 12 Technology 100 (ISO 5) : no sticking or wetting of the specimen Face 90 (ISO 4) : Slight or random sticking or wetting of the specimen face 80 (ISO 3) : wetting of the specimen face at spray point 70 (ISO 2) : Partial wetting of the specimen face beyond the spray points 50 (ISO 1) : complete wetting of the entire specimen face beyond spray point 0 : complete wetting of the entire face of specimen NED University Of Engineering & 13 Technology  GENERAL REQUIREMENTS Grade ISO 4 TO ORIGINAL ISO 5 STATE AFTER AS AGREED AGREED NO. BTWEEN THE OF WASHES PARTIES NED University Of Engineering & 14 Technology  Spray test to simulate exposure to rain AATCC 35 NED University Of Engineering & 15 Technology  PURPOSE & SCOPE This test method is applicable to any textile fabric, which may or may not have been given a water-resistant or water- repellent finish. It measures the resistance to the penetration of water by impact, and thus can be used to predict the probable rain penetration resistance of fabrics. It is especially suitable for measuring the penetration resistance of garment fabrics. NED University Of Engineering & 16 Technology  PURPOSE & SCOPE With the instrument, tests may be made at different intensities of water impact to give a complete overall picture of the penetration resistance of a single fabric or a combination of fabrics. The results obtained with this test method depend on the water repellency of the fibers and yarns, and on the construction of the fabric. NED University Of Engineering & 17 Technology  PRINCIPLE A test specimen, backed by a weighed blotter, is sprayed with water for 5 min under controlled conditions. The blotter is then reweighed to determine the amount of water which has leaked through the specimen during the test NED University Of Engineering & 18 Technology APPARATAUS 01 02 NED University Of Engineering & 19 Technology APPARATAUS STRUCTURAL DETAIL NED University Of Engineering & 20 Technology  Test Specimens A minimum of three specimens of 20 × 20 cm is cut from the test fabric. Three standard blotting papers 15.2 × 15.2 cm The fabric samples and the blotting paper should be conditioned in an atmosphere of 65 ± 2% RH and 21 ± 1ºC for at least 4 h before testing NED University Of Engineering & 21 Technology  TEST PROCEDURE Weight the blotting paper to the nearest 0.1 g and record The specimen is backed with standard blotting paper and is then clamped in the specimen holder and the assembly is mounted in a vertical rigid support frame. The specimen assembly is positioned into the central portion of the spray at a distance of 30.5 cm from the face of the spray nozzle. A horizontal water spray at 27 ± 1°C is directed against the specimen and is allowed to continue for a period of 5 min. At the end of the spray period the blotter is carefully removed and quickly reweighed to the nearest 0.1 g. NED University Of Engineering & 22 Technology  EVALUATION Water penetration as indicated by the increase in mass of the blotting paper during the 5 min test period is calculated, and the average for the three test specimens is reported. Individual determinations or average values of over 5.0 g may be simply reported to > 5 g. In order to obtain a complete overall picture of the penetration resistance of a fabric or fabric combination the average penetration with different pressure heads on the nozzle should be obtained. NED University Of Engineering & 23 Technology  EVALUATION The pressure head should be varied by 300 mm increments in order to determine (a) the maximum head at which no penetration occurs, (b) the change in penetration with increasing head and (c) the minimum head required to cause “breakdown” or the penetration of more than 5 g of water. At each pressure head a minimum of three specimens should be tested in order to obtain the average penetration for that head. Report the individual determinations. For values of over 5.0 g simply report as 5 + g or > 5 g. NED University Of Engineering & 24 Technology  NOTES The intensities are produced and controlled by means of a column of water which may be adjusted to 0.6, 0.9, 1.2, 1.5, 1.8, 2.1 and 2.4 m above the nozzle. This is done by means of a glass pressure column to which a nozzle is connected. The adjustment is made by a simple setting of a valve at the lower end of the drain or overflow pipe which extends up through the center of the glass column. NED University Of Engineering & 25 Technology AATCC 127, ISO 811 (Hydrostatic pressure tests. These measure the water penetration as function of pressure exerted by water standing on the fabric) NED University Of Engineering & 26 Technology  SCOPE This test method measures the resistance of a fabric to the penetration of water under hydrostatic pressure. It is applicable to all types of fabrics, including those treated with a water resistant or water repellent finish. Water resistance depends on the repellency of the fibers and yarns, as well as the fabric construction. The results obtained by this method may not be the same as the results obtained by the AATCC methods for resistance to rain or water spray. NED University Of Engineering & 27 Technology  APPARATUS 01 02 distilled or de-ionized Water 03 Hydrostatic pressure NED University Of Engineering & head Tester Technology 28  TESTING CAN BE CARRIED OUT AT 1. Static Conditions (constant pressure, time vary) 2. Dynamic Conditions (constant rate of water flow ex. 60mb/min etc.) NED University Of Engineering & 29 Technology  TESTING CAN BE CARRIED OUT AT 1. As Received 2. After The Number Of Washes As Agreed IF, TEST NEED TO BE DONE AFTER WASHING , THEN WASH AS PER THE PROCEDURE DESCRIBED IN AATCC 135(AS PER CARE LABEL FOR WASHING AND DRYING CONDITIONS) NED University Of Engineering & 30 Technology  SAMPLE PREPARATION A minimum of three fabric specimens should be taken diagonally across the width of the fabric to be representative of the material. Cut specimens at least 200 × 200 mm to allow proper clamping. Handle the specimens as little as possible and avoid folding or contaminating the area to be tested. Condition the test specimens at 21± 2°C (70 ± 5°F) air at 65 ± 2% RH for at least 4 h before testing. The surface of the fabric to be exposed to water must be specified because different results may be obtained on the face and the back. Identify that surface on a corner of each specimen. NED University Of Engineering & 31 Technology  TEST PROCEDURE Verify the water in contact with the test specimen is regulated at 21 ± 2°C (70± 5°F). Dry the clamping surface. Clamp the specimen with the surface to be tested facing the water. Select the gradient of 60 mbar/min, press the start button. Disregarding water droplets that appear within approximately 3 mm adjacent to the edge of the specimen clamping ring, record the hydrostatic pressure at the moment water droplets penetrate the fabric in three different places. NED University Of Engineering & 32 Technology  TEST PROCEDURE Disregarding water droplets that appear within approximately 3 mm adjacent to the edge of the specimen clamping ring, record the hydrostatic pressure at the moment water droplets penetrate the fabric in three different places. NED University Of Engineering & 33 Technology END OF THE LECTURE NED University Of Engineering & 34 Technology