GB/T 17253-2018Synthetic filament fabrics (English PDF)

3.1 Synthetic filament fabric

Silk fabric woven, pure or interwoven, mainly from synthetic filament yarn.

[GB/T 26380-2011, definition 3.1.9]

4.1 Content of requirements

The requirements for synthetic filament fabrics comprise basic safety performance and quality requirements. The quality requirements are divided into intrinsic quality and appearance quality.

4.2 Basic safety performance

The basic safety performance of synthetic filament fabrics shall comply with GB 18401; synthetic filament fabrics for infants and children shall comply with GB 31701.

4.3 Assessment items

The intrinsic quality assessment items of synthetic filament fabrics comprise ten items: density deviation rate, mass deviation rate, fibre content tolerance, breaking strength, tearing strength, seam slippage, dimensional change after washing, colour fastness, pilling and drape coefficient; the drape coefficient is assessed only for imitation silk fabrics. The appearance quality assessment items comprise three items: colour difference (compared with the reference sample), width deviation rate and appearance defects.

4.4 Grading rules

4.4.1

Synthetic filament fabrics are graded by the piece. Mass deviation rate, fibre content tolerance, breaking strength, tearing strength, seam slippage, dimensional change after washing, colour fastness, pilling and drape coefficient are graded by batch; density deviation rate and appearance quality are graded by piece.

4.4.2

The quality grade of synthetic filament fabrics is determined by the lowest-graded item among intrinsic quality and appearance quality. The grades are superior grade, first grade and second grade; fabric below the second grade is off-grade.

4.5 Grading of intrinsic quality

The grading rules for the intrinsic quality of synthetic filament fabrics are given in Table 1.

Table 1 - Grading rules for intrinsic quality (values given as superior grade / first grade / second grade):

Density deviation rate, %: ±2.0 / ±3.0 / ±4.0.

Mass deviation rate, %: ±3.0 / ±4.0 / ±5.0.

Fibre content tolerance, %: in accordance with GB/T 29862.

Breaking strength (a), N >= 200 for all grades.

Tearing strength (b), N >= 9.0 for all grades.

Seam slippage (fixed load) (c), mm <= 6 for all grades; fixed load: below 55 g/m2, 45.0 N; 55 g/m2 to 150 g/m2, 80.0 N; above 150 g/m2, 100.0 N.

Dimensional change after washing (d), %: -2.0 to +2.0 for superior and first grade; -3.0 to +2.0 for second grade.

Colour fastness, grade >= - to water, soap washing and perspiration: colour change 4 / 4 / 3-4; staining 3-4 / 3 / 3.

Colour fastness, grade >= - to rubbing: dry 4 / 3-4 / 3; wet 3-4 / 3, 2-3 for dark shades (e) / 3, 2-3 for dark shades (e).

Colour fastness, grade >= - to dry cleaning (f): colour change 4 / 4 / 3-4; staining 4 / 3-4 / 3-4.

Colour fastness, grade >= - to hot pressing: colour change 4 / 3-4 / 3.

Colour fastness, grade >= - to light: 4 / 3 / 3.

Colour fastness, grade >= - to saliva (g): 4 / 4 / 4.

Pilling, grade: 4 / 3-4 / 3.

Drape coefficient (h): in accordance with FZ/T 43045.

(a, b) Not assessed for gauze, leno and burnt-out fabrics or fabrics given special finishing processes.

(c) Not assessed for gauze, leno and burnt-out fabrics, habotai-type fabrics with a mass per unit area of 45 g/m2 or less, satin fabrics of 67 g/m2 or less, fabrics given special finishing processes, or fabrics for scarves. Where the test result is slippage out of the seam, fabric breakage or tearing, the fabric is judged off-grade.

(d) Not assessed for easily deformed fabrics such as gauze, leno, burnt-out and crepe-type fabrics.

(e) Shades deeper than the 1/12 standard depth card of GB/T 4841.3 are dark shades.

(f) Not assessed for fabrics that cannot be dry-cleaned.

(g) Assessed only for products for infants.

(h) Assessed only for imitation silk fabrics.

4.6 Evaluation of appearance quality

4.6.1

The grading rules for the appearance quality of synthetic filament fabrics are given in Table 2.

Table 2 - Grading rules for appearance quality (superior grade / first grade / second grade): Colour difference (compared with the reference sample), grade >= 4 / 3-4 / 3-4; Width deviation rate, %: -1.0 to +2.0 / -2.0 to +2.0 / -2.0 to +2.0; Limit of appearance defect score, points/100 m2: 10 / 20 / 40.

4.6.2

The scoring of appearance defects of synthetic filament fabrics is given in Table 3.

Table 3 - Scoring of appearance defects (1 point / 2 points / 3 points / 4 points):

1 Warp-direction defects: 8 cm or less / over 8 cm to 16 cm / over 16 cm to 24 cm / over 24 cm to 100 cm.

2 Weft-direction defects: 8 cm or less / over 8 cm to half the width / - / over half the width. Weft bars (b): - / normal / - / obvious.

3 Dyeing and finishing defects: 8 cm or less / over 8 cm to 16 cm / over 16 cm to 24 cm / over 24 cm to 100 cm.

4 Stains and damage-type defects: - / 2.0 cm or less / - / over 2.0 cm.

5 Selvedge defects (c): 1 point per 100 cm or less in the warp direction; no 2, 3 or 4 point category.

6 Weft skew, pattern skew, check skew and uneven width: 4 points for 100 cm or less where the deviation exceeds 3%.

Note: for the classification of appearance defects, see Annex A.

(a) For the definitions of defects, see GB/T 30557.

(b) A weft bar of 10 cm or less in the warp direction counts as one bar.

(c) Pin-plate holes extending 1.5 cm or less into the inner width are not counted.

4.6.3

Notes on the scoring of appearance defects of synthetic filament fabrics:

a) appearance defects are scored cumulatively up to a limit;

b) the length of an appearance defect is measured in its greatest dimension in the warp or weft direction;

c) colour difference within the same piece (uneven shade) not lower than grade 4 scores 4 points per 1 m or less;

d) the cumulative score within 1 m in the warp direction is at most 4 points; any excess is counted as 4 points;

e) the grading limit for warp streaks of normal degree and other continuous defects running the full piece is second grade; warp streaks of obvious degree and other continuous defects running the full piece are off-grade;

f) severe continuous defects score 4 points per metre; beyond 4 m the fabric is downgraded to off-grade.

4.6.4

The appearance defect grading score of each piece of synthetic filament fabric is calculated with formula (1), and the result is rounded to one decimal place in accordance with GB/T 8170.

c = q / (l × w) × 100 ... (1)

where:

c - appearance defect grading score of each piece of fabric, in points per hundred square metres (points/100 m2);

q - measured appearance defect score of each piece of fabric, in points;

l - length of the piece inspected, in metres (m);

w - effective width, in metres (m).

4.7 Rules for cutting and joining pieces and for defect marking allowances

4.7.1

For synthetic filament fabrics, either cutting and joining of pieces or defect marking with length allowance is permitted, but only one of the two may be used.

4.7.2

The sections of a cut-and-joined piece shall be consistent in grade, width, shade and pattern.

4.7.3

Synthetic filament fabrics are permitted one defect marking per 20 m or less on average. Defects scoring 3 or 4 points may be marked; continuous defects longer than 10 cm may be marked consecutively. Each marked defect is given an allowance of 10 cm, and a defect once marked is no longer scored. The distance between markings of local defects, or between a marked defect and the end of the piece, shall be not less than 4 m.

5.1 Test methods for intrinsic quality

5.1.1 Density deviation rate

In accordance with GB/T 4668-1995: method C may be used for warp density and method E given in the annex for weft density; method A is used for arbitration testing.

For each piece, weft density should be measured at five places at least 3 m from either end, with the measuring places preferably at least 2 m apart; the arithmetic mean of the measured values is calculated and rounded to 0.1 threads/10 cm in accordance with GB/T 8170.

5.1.2 Mass deviation rate

In accordance with method 5 of GB/T 4669-2008; arbitration testing is carried out with method 3.

5.1.3 Fibre content tolerance

In accordance with GB/T 2910 (all parts), FZ/T 01026, FZ/T 01057 (all parts) and FZ/T 01095.

5.1.4 Breaking strength

In accordance with GB/T 3923.1.

5.1.5 Tearing strength

In accordance with GB/T 3917.2.

5.1.6 Seam slippage

In accordance with GB/T 13772.2. The specimen width is 75 mm, and the load values are as specified in Table 1.

5.1.7 Dimensional change after washing

In accordance with GB/T 8628, GB/T 8629-2017 and GB/T 8630. Washing procedure 5M of GB/T 8629-2017 and drying procedure A of GB/T 8629-2017 are used. Two specimens are taken for each sample; three specimens are taken for arbitration testing.

5.1.8 Colour fastness

5.1.8.1

The test method for colour fastness to water is in accordance with GB/T 5713.

5.1.8.2

The test method for colour fastness to soap washing is in accordance with GB/T 3921-2008; test condition C(3) is used for pure synthetic filament fabrics (except nylon), and method A(1) for other synthetic filament fabrics.

5.1.8.3

The test method for colour fastness to perspiration is in accordance with GB/T 3922.

5.1.8.4

The test method for colour fastness to rubbing is in accordance with GB/T 3920.

5.1.8.5

The test method for colour fastness to dry cleaning is in accordance with GB/T 5711.

5.1.8.6

The test method for colour fastness to hot pressing is in accordance with GB/T 6152, using the damp pressing method; the temperature is 150 °C for pure synthetic filament fabrics (except nylon) and 110 °C for other synthetic filament fabrics.