Draft Copy Textiles High Tenacity Yarn of Nylon or other Poly-amides Specification (HS: 5402.19) Foreword High tenacity Nylon or other polyamides: High tenacity yarn: A yarn with a significantly higher breaking tenacity than others of the same generic category, generally used because of that main characteristic. Tenacity is the customary measure of strength of a yarn; it is usually defined as the ultimate (breaking) force of the yarn (in gram-force units) divided by the denier or tex. Because denier or tex is a measure of the linear density, the tenacity works out to be not a measure of force per unit area, but rather a quasi-dimensionless measure analogous to specific strength. Identifying High-Tenacity and Non-High-Tenacity Yarns: The HTSUS defines high-tenacity yarn as yarn having tenacity, expressed in cn/tex (centinewtons per tex), greater than the following: For single yarn of nylon or other polyamides: 60 cn/tex. For multiple (folded) or cabled yarn of nylon or other polyamides: 53 cn/tex. The force exerted at the breaking point is then divided by the linear density to calculate the tenacity. In addition to the above, there are numerous guidelines which, although not conclusive, may suggest whether a yarn is high-tenacity: Industrial yarns would seldom be bleached or colored or dyed. Filament textile yarns (the term the trade uses for yarns made for apparel and furnishings) generally would not exceed 900 denier (990 decitex), while industrial yarns (the trade term for yarns for industrial 1 of 12
applications such as tires) would generally be 1100 denier (1210 decitex) and higher. Textile yarns would generally be shipped in protective cartons because of their fragility, while tubes of the tougher industrial yarns may be stacked directly on skids and shrink-wrapped in plastic. If a yarn can be easily pulled apart by hand, it is probably not a hightenacity yarn. The ultimate consignees or end-users of high-tenacity industrial yarns would normally be tire or rubber product manufacturers or converters. The automotive sector is by far the largest end-use market for these yarns. Another major application is in reinforcing automotive and appliance belts. High-tenacity yarn also has some other minor end uses such as thread for shoes, webbing or strapping, and ballistics fabrics used to make bulletproof clothing. Application of High Tenacity Nylon: Nylon high tenacity yarn is produced from specially treated polyamide polymers and is used in tires, for coated fabrics, tarpaulins, as reinforcement in rubber hoses and conveyor belts, safety belts, ballistic cloth, netting, ropes, parachutes, racket strings, tents, industrial sewing threads, sleeping bags, cables and hawsers. 1. SCOPE This draft Standard specifies requirements for the classification of all types of High Tenacity Yarn of Nylon or other polyamides for various end usages. 2 of 12
2. REFERENCES The standards given in Appendix contain provisions which, through reference in this text, constitute provisions of this standard. 3. TERMINOLOGY This heading lists the technical terms used for high tenacity yarn of nylon or other polyamides as defined in various test methods /manufacturer s booklets. 3.1. Breaking force: The maximum force applied to a test specimen carried to rupture during a tensile test 3.2. Breaking strength: Term still commonly used, but improperly, for the average of the results of breaking force measurements. 3.3. Breaking tenacity: The breaking force divided by the linear density of the unstrained material. 3.4. Breaking toughness: The work required to achieve the breaking force of the test specimen expressed per unit length and linear density of the unstrained material. 3.5. Cabled yarn: yarn with two or more components of which at least one is a folded yarn, combined by one or more twisting operations. Note: For certain industrial uses the word cord is used for folded or cabled yarns. 3.6. Elongation: The ratio of the extension of a test specimen to its initial length, expressed as a percentage. a) Elongation at break: The elongation of a test specimen produced by the breaking force. b) Elongation at rupture: The elongation of a test specimen 3 of 12
corresponding to rupture. c) Elongation at specified force: The elongation of a test specimen produced by a specified force. d) Elongation at specified tenacity: The elongation of a test specimen produced by a specified tenacity. e) Elongation between defined forces: The increase in length of a test specimen which results from subjecting it to two specified forces. 3.7. Folded yarn: A yarn in which two or more single yarns are combined by a single twisting operation. 3.8. Industrial Yarn: Yarn intended for use in products other than nonprotective clothing, household, furnishing and floor coverings selected principally but not exclusively for their performance and properties as opposed to their aesthetic or decorative characteristics. 3.9. Modulus: The property of a material representative of its resistance to deformation. In tensile testing the modulus is expressed as the ratio of tenacity to strain. 3.10. Modulus, wet: The modulus determined when the material is completely wet. In the definition of the generic name "modal", the term "wet modulus" is defined as the tenacity required producing an elongation of 5 % when the specimen is completely immersed in water. 3.11. Moisture content: The amount of water contained in a material, expressed as a percentage of its total mass (including moisture and any extractable). 3.12. Shrinkage: The decrease in length of a test specimen caused by a specified treatment, expressed as a percentage of the length of the untreated test specimen. The lengths are measured before and during or after treatment under specified tensions. a) Boiling water shrinkage: The decrease in length of a test specimen 4 of 12
caused by a treatment in boiling water for specified time, expressed as a percentage of the length of the untreated test specimen. The lengths are measured before and after treatment under a specified pretension. b) Hot water shrinkage: The decrease in length of a test specimen caused by a treatment in hot water under a specified temperature and time, expressed as a percentage of the length of the untreated test specimen. The lengths are measured before and after treatment under a specified pretension. The water temperature to be applied is specified between buyer and seller. c) Hot air shrinkage, after treatment: The decrease in length of a test specimen caused by a treatment in hot air under specified temperature and time, expressed as a percentage of the length of the untreated test specimen. The lengths are measured before and after treatment under a specified pretension. d) Hot air shrinkage, during treatment: The decrease in length of a test specimen caused by a treatment in hot air under specified temperature and time, expressed as a percentage of the length of the untreated test specimen. The lengths are measured before (under a specified pretension) and during treatment (under a specified measuring tension). 3.13. Strain: The ratio of the extension of a test specimen to its initial length. 3.14. Stress: The resistance to deformation developed within a material subjected to an external force, expressed as force per cross-sectional area. 3.15. Tenacity: Force divided by linear density. 3.16. Tenacity at specified elongation: The tenacity associated with a specified elongation on the tenacity-elongation curve. 3.17. Tensile stress: The force per unit cross-sectional area of the unstrained specimen. 5 of 12
3.18. Tensioning force: An abbreviation for tensioning force. In fibres and yarns the tension applied is usually based on the linear density of the material. Sl. No. 1. 2. 4. REQUIREMENTS OF HIGH TENACITY YARN OF NYLON OR OTHER POLYAMIDE 4.1. The High Tenacity Nylon or other poly amide shall meet the constructional and performance requirements specified in Table- 4.1. Table- 4.1: Constructional and Performance Requirements of High Tenacity Nylon or Other Poly-amide Characteristic Linear Density (Denier) Specified Value No. of Filaments Specified Value Single Yarn Requirement Value CV % Max Folded Single / Yarn Cabled As declared + 2.5 % As declared + 2 Filaments Folded / Cabled Less than or equal to 2% Method of Test IS 1226:1957 --- Annex- A 3. Tenacity (cn/tex)) Not less Not less Less than or than 60 than 53 equal to 5% IS 1670:1991 4. Elongation at Break % 25% ± 3 Less than or equal to 8% 5. Hot Air Shrinkage % 10% + 2 Not applicable ASTM D 4974-04 IS 3025(- 6. Oil Content % Less than or equal to 1.5% PART 39) :1991 4.2. Freedom from Yarn Defects - The yarn shall be free from the following major defects: 4.2.1. Dirt/Grease No soiling or grease spots shall be allowed. It is acceptable if the spots can be cleaned off. Air strip yarn to remove dirt on the outside surface,. For dirt on the ends, clean with sprayer. If dirt does not come off, reject to off grade. 6 of 12
4.2.2. Wound in Waste - None allowed. Strip to correct or reject to rewind. 4.2.3. Damaged/bumped None allowed. Strip to correct or reject to rewind. 4.2.4. Finish oil Contamination Dry or regular oil yarn shall not be contaminated with Finish Oil when viewed under a packing table UV light, unless very slight (not immediately visible). Strip to clean if possible. Otherwise reject to off-grade. 4.2.5. Broken Filaments The number of broken filaments shall not be more than 8 per end for standard package and not more than 10 per end for large package. The number of broken filaments depends upon the Denier per filament (DPF) 4.2.6. Fluorescent Oil - If applicable, the package shall have even coverage under UV light. 4.2.7. Crossed Ends - Nose end crosses can be allowed, unless they appear matted or too numerous to count. Up to 25 mm crosses on the tail end are allowed or crosses < 6 mm from the tube shall be allowed. 4.2.8. Slubs/Loops/Kinks - None shall be allowed. 4.2.9. Proper Wind - No patterns or bands, no high or falling off edges and no excessive hard/soft packages shall be allowed. 4.2.10. Tube Defects - No crushed, nicked, or cut tubes, especially on the nose end shall be allowed. 4.2.11. Ridges/Grooves No ridges or grooves > 3mm high or deep shall be allowed. 4.2.12. Twist For single ply yarns only, Z twist shall rotate clockwise when allowed to relax and S twist rotates counter-clockwise. 4.2.13. Proper Ply Count the number of ends if the yarn is three ply or more. Air strip the yarn to correct if possible. Also check the tail. 4.2.14. Latching Filaments or plies that separate when winding off package shall not be allowed. 7 of 12
4.2.15. No Tail Only one tail package per layer shall be permitted. The minimum tail length shall be one wrap around the tube. If tail is too short, take a short length of yarn and tie it on to the tail. For parallel yarn smalls and no tails are allowed. 4.2.16. Multiple Tails If there are multiple tails, then correct if possible or reject to rewind. 4.2.17. Tube Clearance It shall be 9 mm, Min from yarn roll to tail end of tube and 25 mm Max ( nominal should be 15 mm) 4.2.18. Oversize or Small Package Check suspect packages with appropriate gauge, scale, diameter tape, or balance. Do not put excessive minimum size packages in one case. 5. SAMPLING AND CRITERIA FOR CONFORMITY 5.1. Lot: The number of cartons of High Tenacity Nylon or other Polyamide of the same type and designation delivered to a buyer against one dispatch note shall constitute a lot. The number of cartons of High Tenacity Nylon or other Polyamide to be selected at random from a lot shall be according to col 2 of Table- 5.1. From each carton one cheese shall be selected at random to constitute the sample size. To ensure the randomness of selection, IS 4905 may be followed. 5.2. Number of Tests and Criteria for Conformity: The number of cheeses to be selected for manufacturing defects shall be in accordance with col 2 of Table-5.1. For linear density, number of filaments, elongation, tenacity, and commercial mass, etc.., the number of cheeses selected shall be in accordance with col 4 of Table- 5.1. For all other properties, the number of cheeses selected shall be in accordance with col 5 of Table-5.1. 8 of 12
TABLE-5.1. SAMPLE SIZE 1 2 3 4 5 Lot Size, Number of Sample Size, Permissible Number of Sub-sample Size Sub-subsample Size cartons of HT PA Number of cartons Nonconforming cheeses Up to 50 5 0 3 2 51 150 8 0 5 3 151 300 13 1 5 3 301 500 20 1 8 5 501 1000 48 3 10 7 All the cheeses selected for requirements shall be tested for those requirements as specified in Table-4.1. All the selected cheeses from the lot shall be visually examined for yarn defects as specified in sub heading 4.2. A cheese shall be declared defective if it contains at least four yarn defects or it does not meet any of the requirements specified in this standard. The lot shall be declared conforming to the requirements of this standard if the total number of defective cheeses does not exceed the value given in col 3 of Table-5.1. 9 of 12
Sl. No. 1. 2. 3 4 5 6 5.3. Declaration of Results: Characteristic Linear Density (Denier) Specified Value CV % No. of Filaments Specified Value Table- 5.2 Declaration of Results: Observed Accepted Accept Single Yarn Folded / Cabled Single Yarn Folded / Cabled able or Not CV % Tenacity (gpd) CV % Elongation at Break % CV % Hot Air Shrinkage % CV % Oil Content % CV % Result: The above yarn qualifies / does not qualify as High Tenacity Yarn. 10 of 12
APPENDIX LIST OF REFERRED STANDARDS STD No Title IS 6239:1971 Generic names for Manmade Fibres. IS 4905:1968 Methods for random sampling IS 7867:1975 Continuous filament textile polyamide (nylon) yarn IS 7703-1:1990 Methods of Test for Continuous Filament polyester filament polyester and polyamide flat yarn, Part 1: Linear Density. IS 7703-2:1990 Methods of Test for continuous filament polyester and polyamide flat yarn, Part 2: Tenacity and Elongation at break. IS 7703-4:1981 Methods for Test for Continuous Filament Polyester and Polyamide Flat Yarn, Part 4: Sampling IS 0686:1985 Methods for determination of colour fastness of textile materials to daylight (first revision) IS 0766:1988 Method for determination of colour fastness of textile materials to rubbing (first revision) IS 3456:1966 Method for determination of water soluble matter of textile materials IS 6590:1972 Specification for braided nylon ropes for mountaineering purposes IS 9936:1992 Manila, nylon, polyester and polypropylene ropes for marine purpose - Guide on equivalence (first revision) IS 4401:2006 Textiles-Twisted nylon fishnet twines (fifth revision) IS 7533:2003 Textiles - Polyamide (nylon) monofilament line for fishing - Specification (first revision) IS 7703:1987 Methods of test for continuous filament polyester and polyamide flat yarn Unevenness percentage (Part 5) IS 14563:1998 Textiles- Determination of formaldehyde Part 1 Free formaldehyde (Part 1 IS 15570:2005 Textiles- Method of test- Detection of banned azo colourants in coloured textiles IS 15651:2006 Textiles Requirements for environmental labelling Specification ASTM D4974-04 Standard Test Method for Hot Air Thermal Shrinkage of Yarn and Cord Using a Thermal Shrinkage Oven 11 of 12
ANNEX - A METHODS FOR DETERMINATION OF NUMBEFR OF FILAMENTS A-1 APPARATUS Microscope Microscopic Slides Glycerol / Water Cutter & Measuring Scale A-2 PRINCIPLE The specimens in the form of filament yarn are cuttings from different places so as to cover the entire surface in each direction/different cones. Mount those specimens on the microscopic slides using glycerol / Water. A-3 PROCEDURE Take 5 specimens of yarn cuttings from separated different places so as to cover the entire surface in each direction/different cones. Mount the specimens on the microscopic slides using glycerol and tease the strands so as to achieve maximum separation of all individual filaments. Mount the slides on the microscope. Count the individual no of filaments visually. Note down the no of filaments on the work sheet. Repeat the same process for all the specimens. Then report the No of filaments average of five readings as the direction wise incase of fabric. 12 of 12