B I S F A. Testing methods for polyamide filament yarns INTERNATIONAL BUREAU FOR THE STANDARDISATION OF MAN-MADE FIBRES

Transcription

1 B I S F A INTERNATIONAL BUREAU FOR THE STANDARDISATION OF MAN-MADE FIBRES Testing methods for polyamide filament yarns Polyamide Filaments Yarns

2 Edition (This edition replaces the 1995 edition)

3 SCOPE These methods apply to polyamide filament yarns and various derived products as single yarn, interlaced yarns, multiple wound yarns, folded yarns, cabled yarns, yarns on beams monofilament special fabrics (but excluding textured filament yarns and tows for staple fibre) destined for either textile or industrial use. They also apply to polyamide speciality fibres like bi-component and bioactive. Note: Separate booklets are available for Polyamide Staple, BCF and Textured Yarn respectively. Appendix I sets out the definitions of polyamide to which these methods apply. Appendix II sets out the determination of relative humidity of air Annex 1, Saturation vapour pressure over water Annex 2, Relative humidity-psychrometric BISFA 2004 All rights reserved. Unless otherwise specified, no part of this 3 Polyamide Filament Yarns BISFA 2004

4 publication may be reproduced or utilised in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission from the publisher. BISFA Avenue E. Van Nieuwenhuyse 4 B-1160 Brussels Belgium tun@cirfs.org Website:

5 CONTENTS Page Scope 2 Introduction 11 Preface 12 Chapter 1 GENERAL RULES FOR SETTLING OF DISPUTES 14 Chapter 2 DEFINITIONS 16 Chapter 3 SAMPLING General remarks Taking the consignment sample and the number of containers to be sampled Taking the laboratory samples for determination of commercial mass Determination of invoice mass and gross mass of the consignment sample Taking packages from the containers of the consignment sample Determination of the net mass of sampled containers 29 5 Polyamide Filament Yarns BISFA 2004

6 3.4 Taking laboratory samples for determination of properties other than commercial mass Packages to be used as laboratory samples Sampling and determination of commercial mass of tyre cord fabrics Preparing the tabby samples Preparing the laboratory samples for determination of commercial mass Sampling for determinations other than of commercial mass 30 Chapter 4 DETERMINATION OF COMMERCIAL MASS Scope Principle Conventional allowance Apparatus, materials and reagents Apparatus and materials Reagents Test procedure Preparing the laboratory samples and test specimen for determination of commercial mass Operating conditions Determining the mass of the test specimen Cleaning of test specimens 34

7 4.4.5 Determining the oven-dry mass of the test specimens Data to be collected Calculation of properties and statistical evaluation Calculation of properties Verification factor Weighted verification factor Statistical evaluation Consignment sample Number of additional tests of laboratory samples Determination of the commercial mass of tyre cord fabrics Determination of the commercial mass of undipped fabrics Determination of the commercial mass of dipped fabrics Verification factor of tyre cord fabrics Determination of the commercial mass of yarns on beams Verification of invoice mass Presentation of results Example of verification of invoiced mass General Consignment to be verified Collected data Consignment sample Laboratory samples Calculation Verification of invoiced mass 41 7 Polyamide Filament Yarns BISFA 2004

8 Chapter 5 DETERMINATION OF TWIST Scope Principle Apparatus Instrument Auxiliary devices Test procedure Operating conditions Preparing the test specimens and performing the test for single yarns Testing folded yarn Testing tyre cord fabrics Data to be collected Calculation of properties and statistical evaluation Calculation of properties Statistical evaluation Laboratory samples Consignment sample Number of additional tests of laboratory samples Designation of yarns Presentation of results Tolerance 47

9 Chapter 6 DETERMINATION OF LINEAR DENSITY Scope Principle Apparatus Skein winding reel Balance Test procedure Pretension Preparing the test specimens and performing the test Procedure A Procedure B Data to be collected Calculation of properties Testing the linear density of dipped yarns Testing the linear density of yarns from tyre cord fabrics Sampling of consignments of fabrics Testing the linear density of yarns from an undipped fabric Testing the linear density of yarns from dipped cord Calculation of properties and statistical evaluation Calculation of properties Statistical evaluation Laboratory samples Consignment sample 52 9 Polyamide Filament Yarns BISFA 2004

10 Number of additional tests of laboratory samples Presentation of results Tolerance 53 Chapter 7 DETERMINATION OF TENSILE PROPERTIES Scope Principle Apparatus Tensile tester Clamps General testing facilities Preparation of laboratory sample Consignment of filament yarns and cords Relaxed samples preparation Un-relaxed samples preparation Consignments of tyre cord fabrics Test procedure Operating conditions Conditioning of the laboratory samples Instrument setting Pretension Testing speed Deviating condition Reproducible determination of force and elongation at rupture 59

11 7.5.2 Preparation of test specimen and performance of the test Manual test Automatic specimen loading testers Preparation of test specimen and performance test Number of tests Test deficiencies Yarn slippage through the clamps Jaw breaks Modifications to the test procedure Data to be collected Calculation of properties and statistical evaluation Calculation of properties Calculation of elongation Derived variables Evaluation of specific tensile properties Statistical evaluation Laboratory samples Consignment sample Number of additional tests of laboratory samples Presentation of results Tolerance Polyamide Filament Yarns BISFA 2004

12 Chapter 8 DETERMINATION OF DIP CONTENT Scope Principle Apparatus The apparatus and its accuracy Reagents Test procedure Preparing samples Removal of textile material Data to be collected Calculation of properties and statistical evaluation Calculation of properties Statistical evaluation Laboratory samples Consignment sample Presentation of results Tolerance 67 Chapter 9 DETERMINATION OF BOILING WATER SHRINKAGE Scope Principle Apparatus 68

13 9.3.1 Skein-winding reel Length measuring stand Water vessel Additional means Test procedure Operating conditions Preparing the test specimens Multifilaments yarns Monofilaments yarns Measuring the initial length of the test specimens Measuring the initial lengths of the test specimens for monofilaments yarns Thermal treatment of the test specimens Measuring the length of the test specimens after treatment Data to be collected Calculation of properties and statistical evaluation Calculation of properties Statistical evaluation Laboratory samples Consignment sample Number of additional tests of laboratory samples Presentation of results Tolerance 72 Chapter 10 DETERMINATION OF HOT AIR SHRINKAGE (after treatment) Polyamide Filament Yarns BISFA 2004

14 10.1 Scope Principle Apparatus Skein-winding reel Length measuring stand Ventilated oven for temperature up to 250 C Additional means Test procedure Operating conditions Preparing the test specimens Measuring the initial length of the test specimens Thermal treatment of the test specimens Measuring the length of the test specimens after treatment Data to be collected Calculation of properties and statistical evaluation Calculation of properties Statistical evaluation Laboratory samples Consignment sample Number of additional tests of laboratory samples Presentation of results Tolerance 76 Chapter 11 DETERMINATION OF HOT AIR SHRINKAGE (during treatment) Scope 77

15 11.2 Principle Apparatus Skein-winding reel Heating unit, for temperatures up to 250 C Length device integrated into a heating unit Test procedure Operating conditions Preparing the test specimens Setting the initial length of the test specimen Thermal treatment of the test specimen Measuring the hot air shrinkage (HAS) of the test specimen during treatment Number of test specimen Data to be collected Statistical evaluation of properties Statistical evaluation Laboratory samples Consignment sample Number of additional tests of laboratory samples Presentation of results Tolerance 80 Chapter 12 STATISTICS: TERMINOLOGY AND CALCULATIONS Polyamide Filament Yarns BISFA 2004

16 12.1 Definitions Basic statistic Individual value Frequency distribution Frequency Arithmetic mean Overall arithmetic mean Variance and standard deviation Coefficient of variation Confidence limits Number of tests Statistical process control Process capability Accuracy index Capability index Quality index Performance index 87 Appendix I DEFINITION, CODING SYSTEM AND, CHEMICAL FORMULAE OF POLYAMIDE FIBRES 88 Appendix II DETERMINATION OF RELATIVE HUMIDITY OF AIR 89 Annex 1, Saturation vapour pressure over water 92 Annex 2, Relative humidity-psychrometric 94

17 INTRODUCTION This booklet replaces the 1995 edition and retains most of the original concepts whilst taking into account further improvements in the testing procedures and a broader range of products. As it is not always easy to distinguish between yarns for textile use and yarns for industrial use, the test methods given in this booklet have been chosen such that the testing of all polyamide filament yarns (other than textured yarns) is covered. Recently, BISFA has been engaged in a through review of its TERMINOLOGY booklet, particularly the list of terms used in other booklets, and their definitions. Where relevant the new and updated terms and definition have been incorporated in this booklet. A thorough revision of the "Determination of Commercial Mass" has taken place to include the determination of mass on beams and to refine the procedure In the chapter (12) regarding the statistics, a new paragraph regarding the process control has been inserted. The general arrangement of the chapters has been made more concise and much repetition has been eliminated. Great care has been taken to make the texts as uniform as possible in presentation and in a style similar to the other BISFA booklets. The texts as a whole are easier to understand. These improvements should ensure that the procedures recommended by BISFA in this booklet and in its other publications retain their position as the most up-to-date internationally agreed testing methods for man-made Polyamide Filament Yarns and Tyre Cord fabrics. Acknowledgements BISFA wishes to acknowledge and thank Mr. P. Monti from Nylstar Mr. B. Tabor from Acordis, and Mr. M.J. Taylor from Invista who revised this booklet. 17 Polyamide Filament Yarns BISFA 2004

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19 PREFACE One of the principal aims of BISFA as set out in the statutes is to establish, for man-made fibres, rules for classification and nomenclature and standard methods of test to serve as a basis for sound trading practice. The methods of manufacture used for such fibres allow a variety of new materials to be produced and it is therefore becoming increasingly necessary to establish and standardise concepts, which will promote harmonious technical and commercial relationships both at the national and international level. As new fibre products appear, BISFA endeavours to establish suitable new rules and methods for them. These rules and methods embody concepts acceptable to producers, users and testing establishments alike. They currently describe testing methods for checking goods upon receipt and include: the determination of the commercial mass, linear density, and tensile properties for all products and in addition, the length for staple fibres; the shrinkage and twist for filament yarns; the amount of dip for tyre cord yarns and the antibacterial properties for bioactive fibres. maximum tolerances for commercial mass and for certain other fibre related properties for example, linear density, twist, and fibre length. BISFA defines the commercial mass of a consignment in a manner, which is independent of the state in which the material is delivered and, in particular, of fluctuations in the moisture content of the material. The procedure ensures that the buyer can know within narrow technical limits what he is paying for, whatever may be the actual moisture content of the material at the time of delivery. BISFA bases its calculation of commercial mass upon the oven-dry mass of fibre material that, depending on the fibre type, is essentially free of extractable material which may be present to assist fibre processing (e.g. spin finish, lubricant, size, adhesive). The oven-dry mass is corrected 19 Polyamide Filament Yarns BISFA 2004

20 by a numerical constant referred to as the conventional allowance (see Chapter 2. Definition ). For some products further corrections may apply and will be specified in the appropriate booklet. The invoice mass, since it is independent of the actual moisture content, is consequently often different from the mass found upon weighing the goods as delivered. The detailing of the methods of test given by BISFA would be of no value unless the samples measured could be considered as representative of the entire consignment.. BISFA has, therefore, also provided a sampling procedure that is dependent on the number of containers in the consignment. Consequently, the results of the tests according to BISFA methods are valid for the entire consignment and not for individual items such as single packages, spools etc. Attention is drawn to other BISFA publications, in particular the booklet "Terminology relating to man-made fibres". Users of BISFA booklets are responsible for ensuring that the latest and complete edition of the appropriate booklet is employed.

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