ASTM D 629

Designation: D 629 – 08 Standard Test Methods for Quantitative Analysis of Textiles1 This standard is issued under the fixed designation D 629; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense. INTRODUCTION Methods D 629-59 T, Quantitative Analysis of Textiles, were discontinued in 1969 because the responsible subcommittee failed to recommend their adoption as a standard after several years of publication as a tentative. The subcommittee action was based on the members’ knowledge that the standard did not include several fiber types introduced to the textile trade after the method was published, and that the techniques required for their identification were lacking in the text, allowing it to become out of date. The procedures included in the text, however, are believed to be reliable for the fiber types named and the techniques described are currently being used in the trade and are referenced by other standards sponsored by Committee D-13 on Textiles. Reinstatement as a standard using the previously assigned number was requested since the listed procedures were reliable and the text considered to be the best available, though not all inclusive. Extensive editorial changes were made in various sections in 1972, and the methods were reinstated as D 629-72. Editorial changes have again been made throughout the text, and statements on precision and bias and suitability for acceptance testing have been added. The text of Methods D 629-59 T was published by the American Association of Textile Chemists and Colorists in that society’s Technical Manual as “Test Method 20A-1959” issued in the years 1959 through 1974. The AATCC Method was revised completely in 1975 and since published as “Test Method 20A-1975.” 1. Scope 1.1 These test methods cover procedures for the determina- tion of the fiber blend composition of mixtures of the fibers listed in 1.2. Procedures for quantitative estimation of the amount of moisture and certain nonfibrous materials in textiles are also described, for use in the analysis of mixtures, but these are not the primary methods for the determination of moisture content for commercial weights. 1.2 These test methods cover procedures for the following fiber types: 1.2.1 Natural Fibers: 1.2.1.1 Cellulose-Base Fibers: Cotton Hemp Flax Ramie 1.2.1.2 Protein-Base Fibers: Animal hairs (other than wool) Silk, cultivated Silk, Tussah Wool 1.2.2 Man-Made Fibers: 1.2.2.1 Cellulose-Base Fibers: Acetate (secondary) Rayon, viscose or cuprammonium Triacetate 1.2.2.2 Synthetic-Base Fibers: Acrylic Aramid Modacrylic Nylon 6, Nylon 6-6, others Olefin Polyester Spandex 1.3 These test methods include the following sections and tables: Section Referenced Documents 2 1 These test methods are under the jurisdiction of ASTM Committee D13 on Textiles and are the direct responsibility of Subcommittee D13.51 on Conditioning and, Chemical and Thermal Properties. Current edition approved Aug. 1, 2008. Published October 2008. Originally approved in 1941. Discontinued in 2008 and reinstated as D 629 – 08. Last previous edition approved in 1999 as D 629–99. 1 Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States. Section Terminology 3 Summary of Methods 4 Uses and Significance 5 Sampling 7 Purity of Reagents 6 Moisture Content or Moisture Regain 9 Nonfibrous Materials 8 Mechanical Separation or Dissection 10 Chemical Test Methods: Summary of Methods 11 Specimens and Symbols 12 No. 1 Acetate Mixed With Other Fibers 13 No. 2 Modacrylic Mixed With Cellulosic Fiber or Wool 14 No. 3 Nylon 6 or Nylon 6-6 Mixed With Natural Fibers or Rayon 15 No. 4 Rayon Mixed With Cotton 16 No. 5 Wool or Polyester Mixed With Cellulosic Fibers or Silk 17 No. 6 Polyester or Acrylic Mixed With Wool 18 No. 7 Natural Cellulosic Material and Rayon Mixed With Acrylic, Modacrylic, and Polyester 19 No. 8 Polyester Mixed With Olefin 20 No. 9 Polyester Mixed With Acetate or Nylon 6,6-6 21 No. 10 Acrylic Fiber or Linear Spandex Mixed With Nylon or Polyester 22 Microspical Analysis Scope 23 Summary of Method 24 Sampling 26 Apparatus 25 Procedure 27 Indexing Term 28 Table Chemical Methods for Analysis of Fiber Mixtures 1 Solubilities of Various Fibers in Solvents Used in Chemical Methods 2 Comparative Scale for Fineness of Various Textile Fibers 3 Fineness Ranges and Fiber Diameters of Various Textile Fibers 4 Specific Gravity of Various Textile Fibers 5 1.4 The analytical procedures described in the test methods are applicable to the fibers listed in 1.2. The test methods are not satisfactory for the separation of mixtures containing fibers that fall within the same generic class but differ somewhat, either physically or chemically, from each other. These test methods are not satisfactory for the determination of bicom- ponent fibers. NOTE 1—For other methods of analysis covering specific determina- tions, refer to: Test Methods D 461, Test Method D 584, Methods D 885, Test Method D 1113, Test Method D 1334, and Test Method D 2130. Methods for moisture are covered in Methods D 885, Test Method D 1576, Test Method D 2462, Test Method D 2495 and Test Methods D 2654. For the determination of commercial weight, refer to Test Method D 2494. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety and health practices and determine the applica- bility of regulatory limitations prior to use. 2. Referenced Documents 2.1 ASTM Standards:2 D 123 Terminology Relating to Textiles D 276 Test Methods for Identification of Fibers in Textiles D 461 Test Methods for Felt3 D 584 Test Method for Wool Content of Raw Wool— Laboratory Scale D 885 Test Methods for Tire Cords, Tire Cord Fabrics, and Industrial Filament Yarns Made from Manufactured Organic-Base Fibers D 1113 Test Method for Vegetable Matter and Other Alkali- Insoluble Impurities in Scoured Wool D 1193 Specification for Reagent Water D 1334 Test Method for Wool Content of Raw Wool— Commercial Scale D 1576 Test Method for Moisture in Wool by Oven-Drying D 1909 Standard Table of Commercial Moisture Regains for Textile Fibers D 2130 Test Method for Diameter of Wool and Other Animal Fibers by Microprojection D 2462 Test Method for Moisture in Wool by Distillation With Toluene D 2494 Test Method for Commercial Mass of a Shipment of Yarn or Manufactured Staple Fiber or Tow D 2495 Test Method for Moisture in Cotton by Oven- Drying D 2654 Test Methods for Moisture in Textiles 2.2 AATCC Method: 20 A Test Method for Fiber Analysis: Quantitative4 3. Terminology 3.1 Definitions: 3.1.1 textile, n—originally a woven fabric, now generally applied to: (1) staple fibers and filaments suitable for conver- sion to or use as yarns, or for the preparation of nonwoven fabrics, (2) yarns made from natural or man-made fibers, (3) fabrics and other manufactured products made from fibers as defined above and from yarns, and ( 4) garments and other articles fabricated wholly from one or more of the above elements, and articles made principally from the above when the products retain the characteristic flexibility and drape of the original fabrics. 3.1.1.1 Discussion—Typical examples (but not a complete listing) of materials included in the above definitions are: (1) Natural fibers such as cotton, wool, sisal, and asbestos, also silk filaments, after these materials have been subjected to their first preparatory process, and man-made fibers such as rayon, nylon, glass, and metals in the form of spinnable fibers, 2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards volume information, refer to the standard’s Document Summary page on the ASTM website. 3 Withdrawn. The last approved version of this historical standard is referenced on www.astm.org. 4 AATCC Technical Manual, available from the American Association of Textile Chemists and Colorists, P.O. Box 12215, Triangle Park, NC 27709. D 629 – 08 2 monofilaments, multifilament yarns, or tows; (2) Yarn interme- diates such as sliver, roving, and top; yarn in single or plied, spun or filamentous form; threads, cords, and ropes but not metallic cables; yarn substitutes including twisted paper or foil, slit foil, or slit laminated sheets, metallic or plastic monofila- ments; (3) Products made from materials included in (1) or (2), or both, by interlacing in any manner including weaving, knitting, tufting and braiding, bonding, knotting, or felting and including such products as cloths, woven goods, knitted goods, lace, embroidery, nets, webbing, batts, and nonwoven fabrics. Reinforced plastics and papers are not included; (4) Wearing apparel, household, and industrial articles fabricated princi- pally from one or more of the materials listed in (1), (2), and (3). 3.1.2 bicomponent fiber, n—a fiber consisting of two poly- mers which are chemically different, physically different, or both. 3.2 For definitions of other textile terms used in these test methods, refer to Terminology D 123. 4. Summary of Test Methods 4.1 Summaries of the specific methods used for different tests are given in the appropriate sections. 4.2 The methods for fiber analysis are grouped under three headings, as follows: Mechanical Separation or Dissection, Chemical Test Methods, and Microscopical Analysis. NOTE 2—It is assumed that the analyst knows from qualitative tests (as directed in Test Methods D 276) what fibers are present and, therefore, which method of analysis is applicable. The choice of method will depend upon the nature of the material to be analyzed and, in some cases, on the accuracy required. 5. Significance and Use 5.1 Test Methods D 629 for the determination of quantita- tive analysis of textiles may be used for acceptance testing of commercial shipments but caution is advised since information on between-laboratory precision is lacking. Comparative tests as directed in 5.1.1 or by Table D 1909 may be advisable. 5.1.1 In case of a dispute arising from differences in reported test results using Test Methods D 629 for acceptance testing of commercial shipments, the purchaser and the sup- plier should conduct comparative tests to determine if there is a statistical bias between their laboratories. Competent statis- tical assistance is recommended for the investigation of bias. As a minimum, the two parties should take a group of test specimens which are as homogeneous as possible and which are from a lot of material of the type in question. The test specimen should then be randomly assigned in equal numbers to each laboratory for testing. The average results from the two laboratories should be compared using Student’s t-test and an acceptable probability level chosen by the two parties before the testing began. If a bias is found, either its cause must be found and corrected or the purchaser and supplier must agree to interpret future test results in the light of the known bias. 5.2 The effects of the various reagents used in the chemical methods on the residual fibers in a blend depend upon the history of the fibers and, unless otherwise stated, are generally too small or too uncertain to warrant the application of correction factors. 5.3 Fiber composition is generally expressed either on the oven-dry mass of the original sample or the oven-dry mass of the clean fiber after the removal of nonfibrous materials. If nonfibrous materials are not first removed from the textile before the fiber analysis is carried out, or if the treatments described in Section 8 are incapable of removing them, any such materials present will increase the percentage of the fiber constituent with which they are removed during the analysis, assuming they are soluble in the solvent used. 5.4 The analytical methods are intended primarily for the separation of binary mixtures of fibers. These procedures may also be used for the analysis of mixtures containing more than two types of fibers by selecting the best combination of methods to use (Table 1). Since a sequence of solvents on a given fiber may produce different results than the expected results from a single solvent, it is advisable to determine the results of such sequential effects when testing multiple fiber blends. It is sometimes more convenient to separate mechani- cally the yarns in a textile which are of similar types, and then use the appropriate chemical method to analyze each of the components. Table 2 shows the solubilities of the various fibers in different chemical reagents. 6. Purity of Reagents 6.1 Use reagent-grade chemicals in all tests. Unless other- wise indicated, it is intended that all reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where such specifications are available.5 Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determi- nation. 6.2 Unless otherwise indicated, references to water shall be understood to mean water conforming to Type I grade of Specification D 1193. 7. Sampling NOTE 3—It is not possible to provide specific instructions for all types of textile materials to which these analytical methods may be applicable, but a few general recommendations shall be followed. 7.1 Sampling for Acceptance Testing: 7.1.1 Lot Sample—As a lot sample for acceptance testing, take at random the number of shipping containers directed in an applicable material specification or other agreement be- tween the purchaser and the supplier. Consider shipping containers to be the primary sampling units. NOTE 4—An adequate specification or other agreement between the purchaser and the supplier requires taking into account the variability between and within shipping containers so as to provide a sampling plan with a meaningful producer’s risk, consumer’s risk, acceptable quality level, and limiting quality level. 5 Reagent Chemicals, American Chemical Society Specifications , American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed by the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville, MD. D 629 – 08 3 7.1.2 Laboratory Sample—As a laboratory sample for ac- ceptance testing, proceed as follows: 7.1.2.1 Fiber in Bulk—Take one composite sample from each bale or other shipping container in the lot sample with each such composite sample being taken from at least five places in the shipping container. 7.1.2.2 Textile Strands—Take one package at random from each shipping container in the lot sample. 7.1.2.3 Fabric—Take a full width swatch 1 m long or a swatch long enough to contain one pattern repeat, whichever is longer, from the end of each roll of fabric in the lot sample, after first discarding a minimum of 1 m of fabric from the very outside of the roll. 7.1.2.4 Garments—Take one garment at random from each shipping container in the lot sample. 7.1.2.5 Other Textiles—Take one laboratory sample from each shipping container in the lot sample as agreed between the purchaser and the supplier. 7.1.3 Test Specimens—Unless otherwise directed in the test method(s) of interest, prepare a test specimen having a mass of TABLE 1 Chemical Methods for Analysis of Fiber MixturesA Wool Spandex Silk Rayon Polyester Olefin Nylon Mod- acrylic Cellulosic, Natural Aramid Acrylic Triacetate Acetate 1 1 1 1 1 1 1 1 1 1 Triacetate 3 (5) (75)B 9 39 (5) 9 (5) 3 Acrylic (6) (6) (75) 10 (8) 10 10 (57) Aramid (6) Cellulosic, Natural (6)5 (10) (6) (4) 5 5 (3) (2) Modacrylic 2 2 2 2 2 2 2 Nylon 3 (10) (6) 3 9 (8) Olefin (6) (6) (75) 8 Polyester (6) (10) (6) (7) Rayon 5 (6) Silk 6 Spandex (6) AKey to Methods and Reagents: Method No. 1—80 % acetone(cold) Method No. 2—N-Butyrolactone Method No. 3—90 % formic acid Method No. 4—59.5 % sulfuric acid Method No. 5—70 % sulfuric acid Method No. 6—Sodium hypochlorite solution Method No. 7—Curpammonia solution Method No. 8—Hot xylene Method No. 9—90 % formic acid Method No. 10—N,N-dimethylacetamide BEach analytical method is identified by a number and where possible, two methods of analysis are provided for each binary mixture of fibers. The number or numbers inside parentheses refers to the method that dissolves the fiber shown at the top of the diagram. The number or numbers outside the parentheses indicates the method that dissolves the fiber listed at the left side of the diagram. Where two methods are listed for a specific binary mixture, the non-superscript method number represents the method of choice. TABLE 2 Solubilities of Fibers in Solvents Used in Chemical MethodsA Method No. (1) (2) (3) and (9) (4) (5) (6) (7) (8) (10) 80 % Acetone Butyrolactone 90 % Formic Acid 59.5% H2SO4 70% H2SO4 NaOCI Solu- tion Curpam- monia Solution Hot Xylene N,N-dimethyl acetamide(A) RT (B) 75°C Acetate S S PS S S S I I ... ... Triacetate I PS PS S I I I ... S Acrylic I S S I I I I I I S Aramid Cellulosic, Natural I I I I SS S I S ... I Modacrylic I S S I I I I I ... I Nylon I I I S S S I I I I Olefin I I I I I I I I S I Polyester I I I I I I I I I I Rayon I I I I S S I S I I Silk I I I PS S S S ... ... S Spandex ... I I PS I I I ... ... S Wool and Hair Fibers I I I I I IB S ... ... ... AKey to Symbols: S = Soluble PS = Partially Soluble SS = Slightly Soluble (a correction factor may be applied) I = Insoluble BReworked wools are soluble in 70 % H2SO 4 depending upon their previous history. D 629 – 08 4 1.0 to 1.5 g by placing it in a weighing bottle. Place the weighing bottle and specimen in an oven and heat for 1 h at a temperature of 105° to 110°C. Transfer the weighing bottle to a desiccator and allow it to cool to room temperature. For fabrics containing a repeating weave pattern, include all yarns in the pattern within the test specimen. Take the specimen from other units when more than one unit is being tested or analyzed. 7.2 Sampling for Other Purposes—In general, follow the principles specified for samples for acceptance testing. Insofar as the amount of material available and the purposes of the analysis dictate, take a lot sample, laboratory sample, and test specimens in such a manner that all fibers present have a proportional probability of being sampled. 8. Nonfibrous Materials 8.1 Scope—These procedures are intended for the removal of the nonfibrous natural constituents of the fiber and sub- stances added by the manufacturer. Starch, China-clay, soaps, some waxes, some nondrying oils, certain resins, and the usual natural constituents are in this category and are removed by the procedures described. However, general directions for the removal of all possible substances which may be present cannot be included. Inorganic pigments which are frequently used as delustrants in the manufacture of man-made fibers and types of dyes are not removed by the procedures described in 8.4. Some of the newer finishes present special problems and the analyst will have to deal with these cases as they arise. When it is necessary to modify the procedure to remove nonfibrous constituents, the analyst shall make sure that cleaned (Note 5) specimens of the fibers under consideration do not lose weight when subjected to the same treatment. The treatments desc