Some standard content:
Textile Industry Standard of the People's Republic of China
Cotton covered spandex natural yarn
spandexgreyyarnForeword
FZ/T12010-2001
This standard is formulated with reference to GB/T398~1993 <(Cotton Natural Yarn" standard and 1997 Uster statistical values in terms of main technical contents and technical requirements. The degree of consistency between this standard and the 1997 Uster statistical values is non-equivalent, and the following statistical values of their yarn quality carded cotton yarn (ring spinning) and combed cotton yarn (ring spinning) are used as the basis for formulating relevant quality indicators in the technical requirements of this standard:
a) Coefficient of variation of yarn weight (CV%);
b) Coefficient of variation of yarn uniformity (CV%);
c) Occasional yarn defects (pieces/105m);
d) Breaking strength (cN/tex);
e) Coefficient of variation of breaking strength (CV%).
This standard includes the inspection contents and methods of hollow yarn defects, poorly covered yarn defects and exposed core yarn defects of cotton-spandex core-spun natural yarn. This standard stipulates the absolute number index value of the difference in spandex fiber content (%)
as the grading quality index and the quantitative chemical and physical analysis method of spandex fiber content. This standard is applicable to the quality identification of cotton-spandex core-spun natural yarn with a spandex fiber content of 5% to 15%. Appendix B of this standard, "Quantitative chemical analysis method for fiber content", is formulated with reference to Appendix A of FZ/T73011-1998 (knitted belly band).
The technical level of this standard is equivalent to the international advanced level for superior products, and close to the international general level for first-class products. Appendix A of this standard is a normative appendix.
Appendix B of this standard is a normative appendix
Appendix C of this standard is a normative appendix.
This standard is proposed by China National Textile and Apparel Council. This standard is under the jurisdiction of Shanghai Textile Industry Technical Supervision Institute. Drafting units of this standard: Shanghai Textile Industry Technical Supervision Institute, Beijing Textile Holdings Co., Ltd. 1 Scope
This standard specifies the classification, requirements, test methods, inspection rules, marking and packaging of cotton-spandex core-spun natural yarn (cotton fiber-spun spandex filament).
This standard is applicable to the identification of the quality of the spandex core-spun natural yarn produced by ring spinning with a spandex fiber content of 5% to 15%. This standard is not applicable to the identification of the quality of the spandex core-spun natural yarn for special purposes.
2 Normative references
The clauses in the following documents become the clauses of this standard through reference in this standard. For all dated references, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties to an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For undated references, the latest version shall apply to this standard GB/T398 Cotton grey yarn
GB/T2543.2 Determination of yarn twist - Untwisting and twisting method GB/T2910 Quantitative chemical analysis method for textile two-component fiber blends (eqvISO1833) GB/T3292 Textile yarn unevenness test method - Capacitance method GB/T3916 Textile packaged yarn - Determination of breaking strength and elongation of single yarn (eqvISO2062) GB/T4743 Yarn thread Determination of density Hank method (neqISO2060) FZ/T01050 Classification and inspection method for textile yarn defects Capacitive FZ/T10007 Inspection rules for pure and blended cotton and chemical fiber yarns FZ/T10008 Marking and packaging of pure and blended cotton and chemical fiber yarns FZ/T10013.1 Correction method for breaking strength of pure and blended cotton and chemical fiber products due to temperature and regain Correction method for breaking strength of natural yarn and dyed yarn 3 Terms and definitions
The following terms and definitions apply to this standard. 3.1
Hollow yarn defect
The spandex filaments in the cross section of the core-spun yarn are broken, so that a section of the yarn is only wrapped with cotton fibers but not spandex filaments. 3. 2
Poor covering yarn defect
The spandex filaments are not completely wrapped with cotton fibers in the core-spun yarn, so that part of the spandex filaments are exposed. National Textile Industry Association 2001-12-28 issued 2D02-07-01 implementation 3.3
Exposed core yarn defect
In the core-spun yarn, there is no cotton fiber wrapped around the spandex filaments, so that the spandex filaments are completely exposed. Classification
4.1 The linear density of cotton-spandex core-spun natural yarn is expressed by the weight (g) of 1000m cotton-spandex core-spun natural yarn at the standard moisture regain, which is called tex.
4.2 The raw material code of cotton-spandex core-spun natural yarn is C for cotton and S for spandex. The writing method for the blending ratio of cotton and spandex is: cotton content/spandex content, for example: cotton 93%, spandex 7%, should be written as C/S93/7. 4.3 The official moisture regain of cotton-spandex core-spun natural yarn is calculated by weighted average based on the dry weight blending ratio, with the official moisture regain of cotton being 8.5% and the official moisture regain of spandex being 1.3%. The calculation is accurate to 2 decimal places and rounded to 1 place. The calculation formula is as follows: W=
WcXPc+ WsXPs
Wherein:
Official moisture regain, %;
Official moisture regain of cotton, %;
Official moisture regain of spandex, %;
Cotton content ratio, %;
Spandex content ratio, %.
4.4 The variety code of cotton-spandex core-spun natural yarn is indicated by raw materials, blending ratio, spinning process, yarn density, spandex filament specifications (with parentheses) and use. For example: the linear density of combed cotton-spandex core-spun natural yarn for knitting is 13tex: the specification of spandex filament is 44.4dtex(40D); the blending ratio of cotton and spandex is c/s93/7, and its variety code is: C/S93/7J13[44.4dtex(40D)]K. 4.5 Standard weight of cotton-spandex core-spun natural yarn 4.5.1 Standard weight of 100m yarn at the official moisture regain (g) Tt
mk= 10
Where:
Standard weight of 100m yarn at the official moisture regain, g/100m; yarn tex, tex.
4.5.2 Standard dry weight of 100m yarn (g) Tt
mo= ×100+W
Wherein:
tex
(English
(55~44)
（43~37）
mo——standard dry weight of 100m yarn, g/100m;Tt—yarn tex, tex;
——standard moisture regain,%.
4.6 The designed tex of cotton-spandex core-spun natural yarn must be equal to the nominal tex of its final product. 4.7 The standard weight of 100m of nominal tex of cotton-spandex core-spun natural yarn shall be calculated according to different moisture regains and different blending ratios of cotton and spandex,
For example: c/S93/7J13[44.4dtex Calculation of standard weight of 100m of cotton-spandex core-spun natural yarn: a) Calculation of standard moisture regain W (%) of c/S93/7J13 [44.4dtex (40D)] cotton-spandex core-spun natural yarn: W =
85×93+1.3×7
c/s93／7J13 [44.4dtex (40D)] cotton-spandex core-spun natural yarn 100m of yarn at standard moisture regain b) Calculation of standard dry weight (g/100m) of C/S93/7J13 [44.4dtex (40D)] cotton-spandex core-spun natural yarn 100m of yarn:
Technical requirements of carded cotton-spandex core-spun natural yarn are shown in Table 1. 5. 2
Technical requirements for combed cotton spandex core-spun natural yarn are shown in Table 2. Standard sample numbers for blackboard yarn uniformity for combed cotton spandex core-spun natural yarn are shown in Table 3. Standard sample numbers for blackboard yarn uniformity for combed cotton spandex core-spun natural yarn are shown in Table 4. Grading regulations
5.5.1 Cotton spandex core-spun natural yarn is defined as one batch of the same variety (same spandex filament brand, origin, batch number, and specification) produced in three shifts a day and night. The test is carried out according to the specified test cycle and various test methods, and the yarn quality is evaluated according to the results.
5.5.2 Cotton spandex core-spun natural yarn is graded into superior, first-class, and second-class products. Those with indicators below the second-class index are third-class products. 5.5.3 The superior yarn is evaluated by the single strength coefficient of variation CV (%), the coefficient of variation of 100-meter weight CV (%), the uniformity of the yarn, the number of blackboard cotton neps, the total number of blackboard cotton neps and impurities, the number of hollow yarn defects (pieces/3000m), the number of poorly covered yarn defects (pieces/3000m), the number of exposed core yarn defects (pieces/3000m), the absolute number of differences in spandex fiber content (%), and the lowest one of the 10 items of yarn defects per 100,000 meters.
, the second-class yarn is evaluated by the single strength coefficient of variation CV (%), the coefficient of variation of 100-meter weight CV (%), the uniformity of the yarn, the number of blackboard cotton neps, the total number of blackboard cotton neps and impurities, the number of hollow yarn defects (pieces/3000m), the number of poorly covered yarn defects (pieces/3000m), the number of exposed core yarn defects (pieces/3000m), and the absolute number of differences in spandex fiber content (%). Table 1 Technical requirements for carded spandex core-spun natural yarn Quantity
Single yarn strength per 100 meters Quality
Force variation Quantity variation
(3629)
Yarn evenness
Blackboard yarn evenness
10 boards ratio
(Excellent:
One:Two
Not less than
7:3:0:0
0:7:3:0
0:0:3:7
7:3:0: 0
0:7:3:0
0:0:3:7
7:3:0:0
0:7:3:0
Blackboard cotton
Consolidated impurities
Yarn uniformity
Coefficient of variation
CV%≤
Total number of net grains
Superior yarn
pieces/10°m
Single yarn breaking
100m weight
Rupture strength
cN/tex
(gf/tex)
Quantity deviation
Poor covering
pieces/3000m
pieces/3000m
Spandex fiber
Content%
Absolute difference
Number range
Twist coefficient
(28°19)
(18~17）
Tex
(English System
Count）
(56~44)
(43~37)
(3629)
(28°19)
(18~15)
Single yarn strength 100 meters
Force variation Variation
：0：3：
7:3:0:0
0:7:3:0
0:0:3:7
7:3:0:0
0: 7:3: 0
0:0:3:7
7:3:0:0
0:7:3:0
0:0:3:7
Strip uniformity
Blackboard strip uniformity
10 boards ratio
(Excellent:
Not less than
7:3:0:0
0:7:3:0
0:0:3:
7:3:0:0
0:7:3:0
0:0:3:
7:3:0:0
0:7:3:0
0:0:3:7
7:3:0:0
0:7:3:0||tt| |0:0:3:7
7:3:0:0
0:7：3:0
0:0:3:7
Technical requirements for combed cotton spandex core-spun natural yarn Quality
Blackboard Blackboard Cotton
Yarn uniformity Cotton knots
Knot impurities
Coefficient of variation
Total number of grains
Superior yarn
pieces/10°m
Single yarn breaking
Burst strength
cN/tex
(gf/tex)
Weight per hundred meters
Quantity deviation
pieces/3000m
Table 3 Standard sample of blackboard strip filling for combed cotton spandex core-spun natural yarn No. Nominal Tex tex(English count)
21～30
61 and above
(5537）
(36～29)
(28～19)
(18~10)
(9 and below）
Standard sample number
Excellent 010
Excellent 020
Excellent 030
Excellent 040
Excellent 060
Poor covering
pieces/3000m
First class 021
First class 031bzxZ.net
First class 041
Table 4 Standard sample number for blackboard uniformity of combed cotton and spandex core-spun natural color yarn No. Nominal tex TEX
(British count)
Standard sample number
pieces/3000m
Spandex fiber
Content%
Absolute difference
Number range
Twist coefficient
8～15
(70～37)
16 and above (36 and below)
Excellent 210
First class 211
First class 221
Excellent 220
5.5.5 When the single yarn breaking strength or 100-meter weight deviation exceeds the allowable range, the single yarn strength coefficient of variation CV (%) and the coefficient of variation CV (%) of 100-meter weight shall be downgraded by one grade on the basis of the original evaluation of the two indicators. If the single yarn breaking strength and the 100-meter weight deviation are both out of the range, they shall be downgraded only once. Until it is reduced to the second grade. 5.5.6 The manufacturer can choose either the blackboard uniformity test or the coefficient of variation of uniformity CV (%) to test the uniformity. However, once determined, it cannot be changed arbitrarily. In the event of a quality dispute, the coefficient of variation of uniformity CV (%) shall prevail.
5.6 The monthly cumulative weight deviation of cotton-spandex core-spun natural yarn shall be weighted averaged according to production. For varieties produced in more than 15 batches per month, it shall be controlled within the range of ±0.5%. 6 Test method
6.1 Test conditions
6.1.1 Each test shall be carried out under the standard conditions specified in the standards of each method. 6.1.2 Rapid test: Due to production needs, it is required to quickly test the quality of the product, and a rapid test method can be used. The rapid test can be carried out under temperature and humidity conditions close to the workshop. However, the temperature and humidity at the test site must be kept stable. 6.2 Test cycle
Generally, the test is conducted once every 2 days, and the i-th test shall be used as the basis for the grading of the batch of yarn. The production volume during holidays can be combined with adjacent batches, but once the cycle is determined, it cannot be changed arbitrarily. 6.3 The inspection of the blackboard uniformity, blackboard cotton nep number, blackboard cotton nep impurity total number, and yarn defects of the sample
yarn all uses cheese yarn (direct weft yarn uses bobbin yarn), and the tests of other indicators all use bobbin yarn. If the user has any objection to the product quality, the finished product quality inspection shall prevail.
6.3.1 The number of bobbins sampled and the number of tests for the coefficient of variation of weight per hundred meters CV(%) and the deviation of weight per hundred meters are shown in Table 5. Table 5
Number of machines used to produce the same variety
Number of bobbins taken on each machine
Number of wisp pulled from each bobbin
Total number of tests for all machines
Number of bobbins sampled and the number of tests
16～2930 and above
30 and above
In order to reduce the number of tubes pulled, the manufacturer can pull 15 tubes for varieties with 5 or less machines, and pull 2 wisp from each tube. 6.4 The test method for the coefficient of variation of weight per hundred meters CV(%) and the deviation of weight per hundred meters shall be implemented in accordance with GB/T4743. Among them, the coefficient of variation of weight per hundred meters CV(%) adopts method 1, the linear density adopts method 3, and the yarn tension is: (1.2 土 0.2) cN/tex. The calculation formula of weight deviation per 100 meters is as follows: m-md×100
Wherein:
Weight deviation per 100 meters, %;
Actual dry weight of the sample, g/100m;
Designed dry weight of the sample, g/100m;
6.5 The test method for single yarn breaking strength and single strength coefficient of variation CV (%) shall be carried out in accordance with GB/T3916. (4)
6.5.1 If the single yarn breaking strength is not tested under standard atmospheric conditions, its test strength shall be corrected in accordance with FZ/T10013. The correction coefficient of the breaking strength of cotton-spandex core-spun natural yarn shall be implemented in accordance with FZ/T10013.1 (Appendix AA.1.1).
6.5.2 The samples of single yarn breaking strength and single yarn breaking strength coefficient of variation CV (%) can be the same sample as the 100-meter weight deviation. Each sample of single yarn has 30 bobbins, each bobbin is tested twice, and the total number is 60 times (if the number of machines is 5 or less, each sample can have 15 bobbins, each bobbin is tested 4 times). The number of samples taken by the fully automatic yarn strength tester is 20 bobbins, each bobbin is tested 5 times, and the total number is 100 times. The pretension in the test conditions is: (1.0 ± 0.1) cN/tex. The test report should indicate the type of strength tester used.
6.5.3 The moisture regain of single yarn breaking strength can use the same moisture regain data of the 100-meter weight deviation test. However, if the two tests are not tested under the same conditions, the moisture regain should be tested separately, and the weight of each sample should not be less than 50g. 6.6 The test method for the uniform hook of the blackboard strip and the test method for the total number of cotton knots and impurities on the blackboard shall be implemented in accordance with Appendix A (supplement) of GB/T398. The tension of the yarn when shaking the blackboard is: (1.2±0.2) cN/tex6.7 The test method for the number of hollow yarn defects (pieces/3000m), the number of poorly covered yarn defects (pieces/3000m), and the number of exposed core yarn defects (pieces/3000m) of cotton-spandex core-spun natural yarn shall be implemented in accordance with Appendix A (normative appendix). 6.8 The spandex fiber content (%) can be selected by the manufacturer by either chemical analysis method or physical analysis method. However, once determined, it shall not be changed arbitrarily. In the event of a quality dispute, the fiber content determined by the chemical analysis method shall prevail. The chemical analysis test method shall be implemented in accordance with Appendix B (normative appendix), and the physical analysis test method shall be implemented in accordance with Appendix C (normative appendix).
6.9 The test method for the coefficient of variation CV (%) of the uniformity of the strip shall be implemented in accordance with GB/T3292. 6.10 The test method for yarn defects (As+Bs+C.+Dz) per 100,000 meters shall be implemented in accordance with FZ/T01050. 6.11 The test method for yarn twist shall be implemented in accordance with GB/T2543.2. The pre-tension in the measurement parameters is: (0.5:k0.05)eN/tex. The sampling regulations for yarn twist test are: each variety and each machine shall be tested at least once a month. The samples shall be uniformly and randomly selected on each machine. Two bobbins per machine shall be selected, but they shall not be selected on the same spindle belt. Each bobbin shall be tested twice, for a total of 40 times. When the twist gear is replaced or other mechanical process adjustments affect the twist, tests shall be carried out at any time to ensure that the actual twist coefficient meets the specified range of technical requirements.
6.12 Yarn package weight
6.12.1 When determining the weight of the yarn at the standard moisture regain, a moisture regain test shall be carried out, and then the weight at the standard moisture regain shall be calculated. Instruments for testing moisture regain: electric ovens for cops, bobbins and hanks. 6.12.2 For sampling of bobbins or cheeses, for batches of 2t or less, one sample is taken for every 0.2t, but not less than 6. For batches of more than 2t, one sample is taken for every 0.5t of the portion exceeding 2t. The sampling should be random and uniform, and attention should be paid to the representativeness of the production shift. When the oven test method is used for bobbins or cheeses (the cheese should be taken at one-third of the thickness of the edge yarn layer), indirect weighing or direct weighing can be used.
6.12.2.1 Indirect weighing method: weigh the bobbins or cheeses before sampling, then shake the sample, and weigh the bobbins or cheeses after sampling. The difference between the two weighings is the weight of the sample before drying. Then put the sample into the oven for drying, weigh it, and then calculate the moisture regain.
6.12.2.2 Direct weighing method: First, remove the outer layer of the cheese yarn to about one-third of its thickness, cut the inner yarn with a knife, and peel it off and weigh it. It is used as the oven weight of the sample. Then put it in the oven, dry it and weigh it, and then calculate the moisture regain. 6.12.3 For the sampling of hank yarn, the total weight of each batch of 2t and below shall not be less than 75g, and the total weight of each batch of more than 2t shall not be less than 150g.
6.12.4 The moisture regain test in the oven shall be carried out in accordance with GB/T4743. 6.12.5 During the packaging process, if the moisture regain changes due to the rise and fall of temperature and humidity, the moisture regain test can be carried out in stages according to the temperature and humidity conditions. According to the test moisture regain at different stages, the dry weight of the package at different stages shall be calculated separately, and no confusion shall be allowed. 6.12.6 According to the actual moisture regain, calculate the weight of the yarn at the official moisture regain according to formula (5). 100+W
Mk = M×100+R
Wherein:
Mk is the weight of the yarn at the specified moisture regain, kg; M\ is the actual weight of the batch of yarn when sampling, kg; W is the specified moisture regain, %;
is the actual moisture regain of the batch of yarn samples, %. 6.13 Representation of test results
The various test results of the batch of yarn are represented by the calculated results of all test values of the test. The calculation accuracy of various test results, except for those already specified, shall be in accordance with Table 6. 7
Inspection rules
shall be implemented in accordance with FZ/T10007.
8 Marking and packaging
8.1 Marking
shall be implemented in accordance with FZ/T10008, and the type, origin, specification and batch number of spandex filament shall be added to the marking content. The marking content shall be in accordance with Figure 1.
8.2 Packaging
According to FZ/T10008.
Table 6 Digital rounding off provisions for calculated values
Single yarn strength coefficient of variation
Significant digits after the decimal point
Weight coefficient of variation per hundred meters
Blackboard yarn uniformity
Coefficient of variation of yarn uniformity
Number of blackboard cotton nep
Total number of blackboard cotton nep impurities
Yarn defects per hundred thousand meters
Breaking strength of single yarn
Hundred meters Weight deviation
Hollow yarn defect
Poorly covered yarn defect
Exposed yarn defect
Spandex fiber content
Twist coefficient
Weight per hundred meters (average per batch)
Average tex
Moisture regain for strength correction
Moisture regain for weight conversion
Square root of tex
10sin
cN / tex(gl / tex)
piece/3000m
piece/3000m
piece/3000m
g/100m
Appendix A
(Normative Appendix)
Cotton fiber content
Spandex fiber content
Variety"
Nominal Tex
Spandex filament brand trademark
Spandex filament origin
Spandex filament specification
Spandex filament batch number
Standard Standard code
Production batch number
Packaging date
Production address
1) Varieties shall comply with the provisions of 4.4.
Figure 1 Marking content
Test method for hollow yarn defects, poorly covered yarn defects, and exposed core yarn defects of cotton-spandex core-spun natural yarn A.1 Principle
Under the specified conditions F, the yarn is shaken into skeins and yarn defects are inspected by eye. A.2 Instrument
Yarn length measuring device, the circumference of the skein should meet the yarn length required by the number of full turns. The recommended circumference is (100 0±0.5)mm. With transverse yarn guide device to avoid yarn accumulation. Equipped with positive feeding system for quantitative tension control. If the same skein is to be used to determine the linear density, execute A.3 Sample preparation according to 6,4
A.3.1 Sampling
The sample should be representative of the whole, and should be randomly sampled. Fixed machine or spindle sampling is not allowed. A.3.2 Sample equipment
One sample is tested for each batch of yarn, and 30 rolls are taken for each sample. One strand of test skein is shaken out from each roll. The test light source is based on natural northern light , there must be a large window, and there must be no light obstruction in the window to ensure sufficient light in the room. If light inspection is used, use a 40W fluorescent lamp. Two lamps are installed in parallel, with the center distance between the two lamps being 15cm~30cm, and the height of the lamp from the ground being 170cm~180cm.
A: 5 Inspection method
According to the specified sample length and winding tension, the skein is taken out by shaking the yarn. The knot should be shorter than 1cm. The yarn frame arm should be retracted before the skein is taken out. The skein length is 100m, and the yarn shaking tension is (1.2±0.2) cN/tex. Use your eyes to inspect yarn defects one by one. The inspection object is at an angle of 40°~45° to the vertical light. The inspector should face the inspection object. The inspection distance is based on the principle that the inspector's eyesight is not difficult to identify the yarn defect. A magnifying glass can be used for observation. A.6 Inspection regulations
A6.1 According to the classification regulations for cotton-spandex core-spun natural yarn, the number of hollow yarn defects (pieces/3000m), the number of poorly covered yarn defects (pieces/3000m), and the number of exposed core yarn defects (pieces/3000m) should be recorded and calculated separately. A: 6.2 The length of yarn defects within 1 turn (including 1 turn) is counted as 1; more than 1 turn to 2 turns are counted as 2, and so on. A. 6.3 After all yarn samples are inspected, the total number of hollow yarn defects, poorly covered yarn defects, and exposed core yarn defects of 30 strands of yarn is calculated separately.
A6.4 Determination of hollow yarn defects, poorly covered yarn defects and exposed yarn defects of cotton-spandex core-spun natural yarn A. 6.4.1 Hollow yarn defects
a) Spandex filament broken ends, length less than or equal to 100cm, each broken end is counted as 1; b) Spandex filament broken ends are exposed on the yarn surface, not counted separately. A.6.4.2 Poorly covered yarn defects
Spandex filament exposed, regardless of the size of the area, length less than or equal to 100cm is counted as 1. A.6.4.3 Exposed yarn defects
Spandex filament exposed length less than or equal to 100cm is counted as 1. A.7 Test report
The test report shall include the following contents:
a) The method of this standard is adopted;
b) The name and number of the sample;
c) The form of the package (cop, cheese, etc.), the number of packages; d) The number of hollow yarn defects, poorly covered yarn defects and exposed yarn defects of cotton-spandex core-spun natural yarn; e) The test date
Appendix B
(Normative Appendix)
Quantitative chemical analysis method for fiber content of cotton-spandex core-spun natural yarn B.1 General test rules
The test room must be well ventilated.
B.1.1 Test equipment
The number of samples shall not be less than 15 packages. When the yarn sample is pre-tensioned so that the yarn strip is in a straight state, a sample of not less than 1g is cut on the length measuring device (the yarn head is cut off). The pre-tension of the yarn is calculated based on the nominal linear density of the yarn: (1.2 ± 0.5) cN/tex. At least 2 copies of each sample
B.1.2 Test reagents and instruments, sample preparation, test steps, calculation of analysis results, test results and test report requirements shall be implemented in accordance with Chapter 4 of GB/T2910. B.2 Content analysis of spandex and cotton fiber blended products-B.2.1 Principle
Dimethylformamide method
Use hot dimethylformamide to dissolve and remove spandex from a sample of known dry weight, wash, dry, cool and weigh the insoluble cotton fiber, and calculate the content percentage of the two components. B.2.2 Reagents
99% dimethylformamide
B. 2.3 Test steps
Put the pretreated sample into a conical flask, add 100ml dimethylformamide solution per gram of sample, stir on a boiling water bath for 20 minutes to dissolve the spandex, filter with a known weight funnel, and wash the remaining cotton fiber in the funnel with dimethylformamide and warm water at the same temperature until it is neutral when checked with an indicator. After each wash, vacuum suction must be used to drain the liquid. Then dry, cool, and weigh.
B, 2, 4 The calculation method shall be implemented in accordance with 4, 5 of GB/T2910. d value: 1.00 for cotton fiber Appendix C
(Normative Appendix)
Quantitative physical analysis method for fiber content of cotton-spandex core-spun natural yarn C.1 Principle
The cotton-spandex core-spun natural yarn is twisted and the surface cotton fiber is manually peeled off to separate the spandex filaments and cotton fibers. The separated spandex and cotton fibers are dried and weighed respectively to calculate the percentage of spandex filaments and cotton fibers. C.2 Instruments
Analytical balance: accuracy of 0.0002g.
Electric blast oven: can maintain a temperature of (105±3)℃. C.2.3 Dryer: equipped with color-changing silica gel. C.2.4 Weighing box (bottle).
C.2.5 Tweezers.
C.3 Sample preparation
C.3.1 Sampling
The sample should be representative of the whole and should contain all kinds of fiber components of the yarn. The number of samples should be sufficient for the test. 3.2 Sample preparation
The number of samples should not be less than 15 packages. When the yarn sample is pre-tensioned so that the yarn is in a straight state, a sample of not less than 1g is cut on the length measuring device (the yarn end is cut off). The pre-tension of the yarn is calculated based on the nominal linear density of the yarn: (1.2±0.2) cN/tex. At least 2 samples of each type are required.
C.4 Test steps
C.4.1 General instructions
C.4.1.1 Splitting
Remove the twist of each sample (manual or mechanical method), peel off the surface cotton fiber by hand or tweezers, leaving the spandex filaments, and put the cotton fiber and spandex filaments into their respective weighing boxes (bottles). C.4.1.2 Drying
Put the split sample in an oven and dry it at (105±3)℃ until it is constant weight (the difference in the weight of the sample obtained by weighing it twice in a row shall not exceed 0.1%).
C. 4.1.2.1 Drying of split sample: Put the split sample in a weighing box (bottle) and place the box cover (bottle cover) next to it. After drying, cover the box cover (bottle cover) and quickly move it into a dryer to cool and weigh it until it is constant weight. C.4.1.3 Cooling
Cool in a dryer. Place the dryer next to the balance. The cooling time is limited to when the sample cools to room temperature (generally not less than 30 minutes).
C.4.1.4 Weighing
After cooling, take out the weighing box (bottle) from the dryer and weigh it within 2 minutes with an accuracy of 0.0002g. Note: During the drying, cooling and weighing operations, the separated samples, weighing boxes (bottles), etc. cannot be touched directly by hand. C.4.2 Operation steps
Put the separated samples into weighing boxes (bottles) of constant weight, dry them in an oven at (105±3)℃, cover the boxes (bottles), transfer them to a dryer for cooling and weighing (C.4.1), and repeat the above operations until constant weight is reached. C.5 Calculation of analysis results
C.5.1 Calculation of net dry content weight percentage of spandex fiber and cotton fiber: Ps =
Pc= 100-Ps
Where:
Net dry content percentage of spandex filament, %; Net dry content percentage of cotton fiber, %;
ms—Dry weight of separated spandex filament sample, g; Dry weight of separated cotton fiber sample, g.
C.6 Test results
The test results are expressed as the average of two tests. If the absolute difference between the results of the two tests is greater than 1%, a third sample test should be carried out and the test results are expressed as the average of the three tests. The test results are calculated accurately to 2 decimal places, rounded to 1 place. C.7 Test report
The test report should include the following:
a) The method of this standard is adopted;
b) The name and number of the sample;
c) The form of the package (cop, cheese, etc.), the number of packages; d) The percentage of each component fiber and filament of the sample; e) The test date.3 Test steps
Put the pretreated sample into a conical flask, add 100ml dimethylformamide solution per gram of sample, stir on a boiling water bath for 20 minutes to dissolve the spandex, filter with a funnel of known weight, wash the remaining cotton fiber in the funnel with dimethylformamide and warm water at the same temperature until it is neutral when checked with an indicator, and use vacuum suction to drain the liquid after each wash. Then dry, cool and weigh.
B, 2, 4 The calculation method shall be implemented in accordance with 4 and 5 of GB/T2910. d value: 1.00 for cotton fiber Appendix C
(Normative Appendix)
Quantitative physical analysis method for fiber content of cotton-spandex core-spun natural yarn C.1 Principle
The cotton-spandex core-spun natural yarn is twisted and the surface cotton fiber is manually peeled off to separate the spandex filaments and cotton fibers. The separated spandex and cotton fibers are dried and weighed respectively to calculate the percentage of spandex filaments and cotton fibers. C.2 Instruments
Analytical balance: accuracy of 0.0002g.
Electric blast oven: can maintain a temperature of (105±3)℃. C.2.3 Dryer: equipped with color-changing silica gel. C.2.4 Weighing box (bottle).
C.2.5 Tweezers.
C.3 Sample preparation
C.3.1 Sampling
The sample should be representative of the whole and should contain all kinds of fiber components of the yarn. The number of samples should be sufficient for the test. 3.2 Sample preparation
The number of samples should not be less than 15 packages. When the yarn sample is pre-tensioned so that the yarn is in a straight state, a sample of not less than 1g is cut on the length measuring device (the yarn end is cut off). The pre-tension of the yarn is calculated based on the nominal linear density of the yarn: (1.2±0.2) cN/tex. At least 2 samples of each type are required.
C.4 Test steps
C.4.1 General instructions
C.4.1.1 Splitting
Remove the twist of each sample (manual or mechanical method), peel off the surface cotton fiber by hand or tweezers, leaving the spandex filaments, and put the cotton fiber and spandex filaments into their respective weighing boxes (bottles). C.4.1.2 Drying
Put the split sample in an oven and dry it at (105±3)℃ until it is constant weight (the difference in the weight of the sample obtained by weighing it twice in a row shall not exceed 0.1%).
C. 4.1.2.1 Drying of split sample: Put the split sample in a weighing box (bottle) and place the box cover (bottle cover) next to it. After drying, cover the box cover (bottle cover) and quickly move it into a dryer to cool and weigh it until it is constant weight. C.4.1.3 Cooling
Cool in a dryer. Place the dryer next to the balance. The cooling time is limited to when the sample cools to room temperature (generally not less than 30 minutes).
C.4.1.4 Weighing
After cooling, take out the weighing box (bottle) from the dryer and weigh it within 2 minutes with an accuracy of 0.0002g. Note: During the drying, cooling and weighing operations, the separated samples, weighing boxes (bottles), etc. cannot be touched directly by hand. C.4.2 Operation steps
Put the separated samples into weighing boxes (bottles) of constant weight, dry them in an oven at (105±3)℃, cover the boxes (bottles), transfer them to a dryer for cooling and weighing (C.4.1), and repeat the above operations until constant weight is reached. C.5 Calculation of analysis results
C.5.1 Calculation of net dry content weight percentage of spandex fiber and cotton fiber: Ps =
Pc= 100-Ps
Where:
Net dry content percentage of spandex filament, %; Net dry content percentage of cotton fiber, %;
ms—Dry weight of separated spandex filament sample, g; Dry weight of separated cotton fiber sample, g.
C.6 Test results
The test results are expressed as the average of two tests. If the absolute difference between the results of the two tests is greater than 1%, a third sample test should be carried out and the test results are expressed as the average of the three tests. The test results are calculated accurately to 2 decimal places, rounded to 1 place. C.7 Test report
The test report should include the following:
a) The method of this standard is adopted;
b) The name and number of the sample;
c) The form of the package (cop, cheese, etc.), the number of packages; d) The percentage of each component fiber and filament of the sample; e) The test date.3 Test steps
Put the pretreated sample into a conical flask, add 100ml dimethylformamide solution per gram of sample, stir on a boiling water bath for 20 minutes to dissolve the spandex, filter with a funnel of known weight, wash the remaining cotton fiber in the funnel with dimethylformamide and warm water at the same temperature until it is neutral when checked with an indicator, and use vacuum suction to drain the liquid after each wash. Then dry, cool and weigh.
B, 2, 4 The calculation method shall be implemented in accordance with 4 and 5 of GB/T2910. d value: 1.00 for cotton fiber Appendix C
(Normative Appendix)
Quantitative physical analysis method for fiber content of cotton-spandex core-spun natural yarn C.1 Principle
The cotton-spandex core-spun natural yarn is twisted and the surface cotton fiber is manually peeled off to separate the spandex filaments and cotton fibers. The separated spandex and cotton fibers are dried and weighed respectively to calculate the percentage of spandex filaments and cotton fibers. C.2 Instruments
Analytical balance: accuracy of 0.0002g.
Electric blast oven: can maintain a temperature of (105±3)℃. C.2.3 Dryer: equipped with color-changing silica gel. C.2.4 Weighing box (bottle).
C.2.5 Tweezers.
C.3 Sample preparation
C.3.1 Sampling
The sample should be representative of the whole and should contain all kinds of fiber components of the yarn. The number of samples should be sufficient for the test. 3.2 Sample preparation
The number of samples should not be less than 15 packages. When the yarn sample is pre-tensioned so that the yarn is in a straight state, a sample of not less than 1g is cut on the length measuring device (the yarn end is cut off). The pre-tension of the yarn is calculated based on the nominal linear density of the yarn: (1.2±0.2) cN/tex. At least 2 samples of each type are required.
C.4 Test steps
C.4.1 General instructions
C.4.1.1 Splitting
Remove the twist of each sample (manual or mechanical method), peel off the surface cotton fiber by hand or tweezers, leaving the spandex filaments, and put the cotton fiber and spandex filaments into their respective weighing boxes (bottles). C.4.1.2 Drying
Put the split sample in an oven and dry it at (105±3)℃ until it is constant weight (the difference in the weight of the sample obtained by weighing it twice in a row shall not exceed 0.1%).
C. 4.1.2.1 Drying of split sample: Put the split sample in a weighing box (bottle) and place the box cover (bottle cover) next to it. After drying, cover the box cover (bottle cover) and quickly move it into a dryer to cool and weigh it until it is constant weight. C.4.1.3 Cooling
Cool in a dryer. Place the dryer next to the balance. The cooling time is limited to when the sample cools to room temperature (generally not less than 30 minutes).
C.4.1.4 Weighing
After cooling, take out the weighing box (bottle) from the dryer and weigh it within 2 minutes with an accuracy of 0.0002g. Note: During the drying, cooling and weighing operations, the separated samples, weighing boxes (bottles), etc. cannot be touched directly by hand. C.4.2 Operation steps
Put the separated samples into weighing boxes (bottles) of constant weight, dry them in an oven at (105±3)℃, cover the boxes (bottles), transfer them to a dryer for cooling and weighing (C.4.1), and repeat the above operations until constant weight is reached. C.5 Calculation of analysis results
C.5.1 Calculation of net dry content weight percentage of spandex fiber and cotton fiber: Ps =
Pc= 100-Ps
Where:
Net dry content percentage of spandex filament, %; Net dry content percentage of cotton fiber, %;
ms—Dry weight of separated spandex filament sample, g; Dry weight of separated cotton fiber sample, g.
C.6 Test results
The test results are expressed as the average of two tests. If the absolute difference between the results of the two tests is greater than 1%, a third sample test should be carried out and the test results are expressed as the average of the three tests. The test results are calculated accurately to 2 decimal places, rounded to 1 place. C.7 Test report
The test report should include the following:
a) The method of this standard is adopted;
b) The name and number of the sample;
c) The form of the package (cop, cheese, etc.), the number of packages; d) The percentage of each component fiber and filament of the sample; e) The test date.
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