GB/T 3291.1-1997Textiles--Terms of textile material properties and test--Part 1:Fibre and yarn (English PDF)

2.1 Cotton maturity

The degree of thickening or fullness of the cotton fiber cell wall.

2.2 Dead fiber

The fiber, after cotton fiber expands under specified conditions, with cell wall thickness equal to or less than one-fifth of the maximum width. Dead fibers have various forms, such as flat ribbon without twisting or ribbon with more twisting.

2.3 Thin-walled fiber

The fiber, after cotton fiber expands under specified conditions, that does not satisfy the characteristics of mature fiber or dead fiber.

2.4 Immature fiber

The fiber, after the cotton fiber expands under the specified conditions, that becomes a spiral or flat ribbon-like fiber with a very thin cell wall and almost transparent outline.

The thickness of its cell wall is less than a quarter of its maximum width.

2.5 Normal fiber

The rod-shaped fiber, after the cotton fiber expands under the specified conditions, that presents a discontinuous cavity and no obvious twisting.

2.6 Mature fiber

The fiber, after the cotton fiber expands under the specified conditions, that has no twisting, the shape is similar to the rod, and the cell wall is fully developed. The thickness of its cell wall is equal to or greater than a quarter of its maximum width.

2.7 Degree of fiber wall thickening

The ratio of the actual cross-sectional area of the fiber cell wall to the area of a circle with the same circumference.

2.8 Maturity coefficient

An indicator for the maturity of cotton fiber. The corresponding value shall be set according to the ratio of the cavity width to the cell wall thickness of the cotton fiber.

2.9 Mature ratio

The ratio of the degree of fiber wall thickening to the artificially selected 0.577 standard degree of thickening.

2.10 Percent maturity

The average percentage of the number of mature fibers in the cotton sample to the total number of fibers.

2.11 Micronaire value

The measurement of air permeability of cotton fiber sample under specified conditions, which is a comprehensive index reflecting the fineness and maturity of cotton fiber;

and expressed in micronaire value. The micronaire value scale is subjected to the micronaire value range of standard cotton designated by the International Association.

2.12 Calibration cotton standard samples

Specially prepared and uniformly mixed cotton samples are used as standard samples after being approved by the standardization management department, with standard values of one or several physical properties and corresponding precision.

2.13 Working cotton standard samples

A batch of uniformly mixed cotton samples with one or several characteristics determined by a professional laboratory.

2.14 Length distribution

A curve graph or histogram that characterizes the percentage of fibers of different lengths by number or weight.

2.15 Fiber length array

The successive array with single fiber or length group arranged by length.

2.26 Overlength staple fiber

Chemical short fibers whose length exceeds a certain limitation of nominal length.

2.27 Multiple length staple fiber

Chemical short fibers whose length is twice or more than their nominal length.

2.28 Fineness

The degree of fiber or yarn thickness. It is expressed by different indicators such as diameter, mass per unit length or length per unit mass.

2.29 Direct system/yarn number system

A system that expresses yarn fineness by the mass of yarn per unit length, namely, linear density. Such as Tex and Denier.

2.30 Linear density

The mass per unit length of fiber or yarn.

2.31 Tex

A unit of linear density, which is the mass grams per kilometer of yarn or fiber.

2.32 Denier

A unit of linear density, which is the mass grams per 9 000 meters of yarn or fiber.

2.33 Indirect system/yarn count system

A system that expresses yarn fineness by the length per unit mass of yarn; such as:

metric count, cotton count.

2.34 Yarn count

The length of the yarn per unit mass.

2.35 Metric count

A unit that expresses the yarn count, which is the length in meters per gram of mass fiber, filament or yarn.

2.36 Cotton count

An English indirect yarn number system, which is a multiple of 840 yards per pound of […]

2.47 Change in length on untwisting

The increase or decrease of the length of the yarn after untwisting, which is expressed by a percentage ratio of the amount of extension or contraction of the specimen to the original length of the specimen.

2.48 Single-fiber breaking strength

The breaking force that is measured when a single fiber specimen is stretched to break, which is expressed in centinewtons (cN).

2.49 Bundle breaking strength

The breaking force that is measured when a bundled fiber specimen is stretched to break.

2.50 Skein breaking strength

The breaking force that is measured from the stranded yarn specimen after being stretched to break.

2.51 Single-strand breaking strength

The breaking force that is measured when a single yarn specimen is stretched to break, which is expressed in centinewtons (cN).

2.52 Breaking tenacity

The ratio of the breaking strength of a material to its linear density, which is expressed in centinewtons per tex (cN/tex).

2.53 Knot breaking strength

The tensile breaking force of a fiber or yarn with a knot of a predetermined shape clamped between the two clamps of the tensile tester.

2.54 Loop breaking strength

The tensile breaking force of two fibers or yarns that are taken from the same package, hooked together in a prescribed manner, and clamped between the two clamps of the tensile tester.

2.55 Skein breaking factor

It indicates the relative index of yarn strength, which is expressed by the product of yarn count and skein breaking strength, also called quality index.

2.56 Skein breaking tenacity

The ratio of the skein breaking strength to the product of the yarn linear density and the number of skein turns.

2.57 Cohesive force

The force that the fibers in the fiber strands and tows that are in contact with each other resist the relative movement.

2.58 Unevenness

The degree of uneven thickness of the yarn along the length direction.

2.59 Length between; Lb

The basic length unit for testing unevenness.

NOTE: The length between may be understood as equivalent to the cutting length when testing the uneven yarn by the cutting and weighing method.

2.60 Mean deviation unevenness; U

In the cumulative test length, the percentage ratio OF the total average of the absolute value of the difference between each linear density value and the average linear density in the length TO the average linear density in the test length.

2.61 Deviation Rate; Rd

The percentage of the ratio OF the sum of the lengths of each section whose thickness exceeds a certain limitation TO the length between on the sliver.

2.62 Bulk

The volume per unit mass of a fiber or yarn that is measured under specified conditions.

2.63 Crimp

The wavy state of fiber or filament yarn.

2.64 Latent crimp

The crimp, after heat treatment or stretching, that the relaxes appear.

2.65 Crimp frequency

The number of crimps per unit length of fiber or filament yarn. There are different ways of expressing the crimp frequency. Generally, it is counted in half or full waveform; and the length is generally straight length or natural length.

2.66 Percentage crimp

The percentage OF the difference between the straight length and the crimp length of a fiber or filament yarn under a specified tension TO its straight length.

2.67 Crimp contraction

The contraction of the fiber or filament yarn that is caused by the crimp development under the specified tension, which is expressed by a percentage ratio of the original length.

2.68 Crimp liveliness

The crimp tendency that the fiber or filament yarn shows immediately after the tension is removed.

2.69 Crimp recovery

The ability of a fiber or filament yarn to return to its original crimp after being subjected to tension.

2.70 Crimp rigidity

The ability of a fiber or filament yarn to maintain crimp after recovery from stretching, which is a measurement of potential bulkiness.

2.71 Crimp stability

The ratio of the degree of crimp of a fiber or filament yarn before and after mechanical treatment under certain conditions.

2.72 Shrinkage

The percentage ratio OF fiber or filament yarn length reduction after treatment under specified conditions TO the original length.

2.73 Heat shrinkage

The percentage ratio of length change of fiber or filament yarn before and after heat treatment (such as dry heat treatment, boiling water treatment, steaming treatment, etc.).

2.74 Twist liveliness

The tendency of the twisted filament yarn to return to its shape before twisting.