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This standard is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.
This standard replaces GB/T 14344-2008 Testing method for tensile of man-made filament yarns. In addition to structural adjustment and editorial changes, the following main technical changes have been made with respect to GB/T 14344-2008:
a) "Application scope" is modified (see Clause 1; Clause 1 of Edition 2008);
b) terms and definitions such as "gauge length", "stress", "strain", "modulus", "initial modulus", "work of rupture" and "breaking toughness" are added (see Clause 3; Clause 3 of Edition 2008);
c) recommended type of clamp is added (see 5.1.3);
d) reel or similar device is deleted [see 5.2 b) of Edition 2008];
e) the requirements for water for laboratory are modified [see 5.2.5; 5.2 f) of Edition 2008];
f) the requirement of "remove at least 100m yarns on the surface from each yarn package" in specimen preparation is added (see 6.1.2.1);
g) the specimen preparation of unsupported yarn packages is modified [see 6.1.2.2; 6.1.2 a) of Edition 2008];
h) the specimen preparation of non-twisted and non-interlaced filament yarns and for wet test is added (see 6.1.2.3 and 6.1.2.4);
i) requirements for conditioning and preconditioning——applicable to dry test are added (see 6.2);
j) standard atmosphere for conditioning and test, as well as conditioning time are modified (see 6.2.1 and 6.2.2; 6.2 of Edition 2008);
k) conditioning and preconditioning requirements for filaments, telescopic cylinders and twisted specimens are added (see 6.2.2.1);
l) the strength range and extension range are deleted (see 6.3.4 and 6.3.5 of Edition 2008);
m) the requirements for specimen loading are modified (see 7.2; 7.1.2 of Edition 2008);
n) loop strength and knot strength are deleted (see 7.2 and 7.3 of Edition 2008);
o) the calculation equations for breaking tenacity, elongation at specified strength and initial modulus are added (see 8.2, 8.3 and 8.5);
p) the calculation equations for modulus, work of rupture and breaking toughness are modified (see 8.4, 8.6 and 8.7; 8.3, 8.4 and 8.5 of Edition 2008);
q) the clause “Tolerance" is deleted (see Clause 9 of Edition 2008);
r) "Recommended value of twist level applied to filament yarn" is added (see Annex A);
s) "Calculation method for increased number of tests" is added (see Annex D);
t) "Statistical value calculation" is modified (see Annex E; Annex C of Edition 2008).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This document was proposed by the China National Textile and Apparel Council.
This document is under the jurisdiction of the National Technical Committee on Man-made Fibers of Standardization Administration of China (SAC/TC 586).
The previous editions of this standard are as follows:
——this standard was issued in 1993 for the first time; it was revised in 2003 for the first time and in 2008 for the second time;
——this is the third revision.
Man-made fibre - Test method for tensile properties of filament yarns
1 Scope
This standard describes the test method for tensile properties of filament yarns for man-made fibre.
This standard is applicable to filament yarns for man-made fibre, excluding spandex and carbon fibre.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 4146 (all parts) Textiles - Man-made fibers
GB/T 6502 Sampling method of man-made filament yarns
GB/T 6503 Man-made fibres - Test method of moisture regain
GB/T 6682 Water for analytical laboratory use - Specification and test methods
GB/T 9994 Conventional moisture regains of textile materials
GB/T 14343 Testing method for linear density of man-made filament yarns
3 Terms and definitions
For the purposes of this standard, the terms and definitions given in GB/T 4146 (all parts) and the following apply.
3.1
gauge length
overall length of fiber measured between the clamping points of the first and second clamps in the initial position
[Source: GB/T 4146.3-2011, 2.1.6, modified]
Example: See Figure 1 for the schematic diagram for clamping point of cable column-shaped clamp.
Key:
A——clamping point.
Note: When the clamping points of the two clamps are in the initial position, the overall length of fiber between the clamping points is the gauge length.
Figure 1 Schematic diagram for clamping point of cable column-shaped clamp
3.2
stress
resistance of fiber to deformation under external force
Note: Generally, it is expressed as force per unit linear density or unit cross-sectional area.
[Source: GB/T 4146.3-2011, 2.5.19, modified]
3.3
strain
deformation of fiber under external force
Note: Generally, it is expressed as corresponding percentage.
[Source: GB/T 4146.3-2011, 2.5.22, modified]
3.4
modulus
parameter used to characterize the deformation feature of fiber, i.e. the ratio of stress increment to strain increment on the stress-strain curve
[Source: GB/T 4146.3-2011, 2.5.28]
3.5
initial modulus
ratio of stress increment to strain increment in the initial straight section on the stress-strain curve of fiber
[Source: GB/T 4146.3-2011, 2.5.29, modified]
3.6
work of rupture
work done by an external force when stretching a fiber until it breaks, that is, the energy absorbed by the fiber in the process of stretching until it breaks
3.7
breaking toughness
work done by an external force when a fiber of unit linear density and unit length is stretched to break
4 Principle
The fiber, under the specified conditions, is stretched to break on a constant rate of extension tester, thus the breaking strength, elongation at break, elongation at specified strength, strength at specified elongation, initial modulus, work of rupture, breaking toughness and other data of tensile properties of the specimen are obtained from the force-extension curve or data acquisition system.
5 Devices and materials
5.1 Constant rate of extension tester (CRE)
5.1.1 CRE shall be equipped with the following devices:
a) manual or automatic specimen loading device:
b) electronic force measuring device;
c) automatic recorder or data acquisition system capable of plotting force-extension curve;
d) clamp capable of clamping fibers at a specified gauge length of at least 250mm;
e) a device with different tensile speeds.
5.1.2 CRE shall meet the following technical requirements:
a) the maximum allowable difference between the actual strength and the indicated strength is less than 1% of the actual strength;
b) the maximum allowable difference between the actual extension and the indicated extension is less than 0.5mm;
c) the clamp shall be able to clamp the specimen without slippage, and shall not damage the specimen and cause rupture at the jaws;
d) the movable clamp moves at a constant speed, with a speed change of less than 4%;
e) the maximum allowable difference for the movable clamp returning to different initial positions is less than 0.25mm during the continuous test.
5.1.3 The types of clamps are recommended as follows:
a) The type of clamp may have some influence on the elongation at break of the specimen, so both the supplier and the purchaser shall use the same type of clamp.
b) The jaws of the standard clamps shall be flat without gasket; however, if the specimen cannot be prevented from slippage, other types of clamps may be used according to the agreement. For example, clamps with gasket clamping surfaces or clamps that are not prone to causing slippage or rupture of filament yarns at jaws are shown in Figure 2.
Figure 2 Schematic diagram for cable column-shaped clamp
5.2 Other test tools and materials
5.2.1 Yarn length measuring machine: used for preparing laboratory samples into test filaments, with the circumference of reel of (1.000±0.002)m, and equipped with reciprocating yarn guide device and coil counting device.
5.2.2 Telescopic cylinder: used for specimen preparation of unsupported yarn packages; for twisted filament yarns, the loss of twist level may be prevented during conditioning or relaxation.
5.2.3 Rotary creel: used for telescopic cylinders, through which the specimens can be easily unwound along the tangent under low tension without changing the twist level.
5.2.4 Water storage container: used for impregnating specimens in water.
5.2.5 Water for laboratory: Grade 3 water complying with GB/T 6682 with a temperature of (20±2)℃.
5.2.6 Nonionic surfactant.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Devices and materials
6 Genera principles for tests
7 Test procedures
8 Calculation of results
9 Test report
Annex A (Informative) Recommended value of twist level applied to filament yarn
Annex B (Normative) Fast conditioning method
Annex C (Informative) Pretension calculation method
Annex D (Normative) Calculation method for increased number of tests
Annex E (Normative) Statistical value calculation
Bibliography
