GB 5885-1986 Test method for whiteness of ramie fiber

This standard is the test method for the whiteness of ramie fiber. All inspections during production, acceptance and delivery shall be conducted in accordance with this standard. GB 5885-1986 Test method for whiteness of ramie fiber GB5885-1986 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Testing method of whiteness of ramie fiber
UDC 677.151/.014
GB 5885—86
This standard is the test method for the whiteness of ramie fiber. All tests required for production, acceptance and delivery shall be conducted in accordance with this standard. 1 Sampling
Perform in accordance with the provisions of 5881—86 "Sampling Method for Test of Physical and Chemical Properties of Ramie". 2
Testing conditions
It can be carried out under normal atmospheric conditions. The lighting in the working area should not be too bright (not higher than 401x). 8 Test cycle
Periodic tests can be carried out according to production needs, and each product variety shall be tested at least once a week. The tests during acceptance and delivery shall be agreed upon by both parties.
4 Test instrument
Whiteness measuring instrument.
5 Test method
5.1 Sample preparation
Handle the obtained samples to make the fibers as straight as possible, and there should be no hemp knots or rough hemp bundles in them. 5.2 Test steps
5.2.1 Adjust the instrument
See Appendix A for instrument operation and adjustment (reference part) 5.2.2 Number of measurement times
Measure each sample 50 times, for a total of 3 samples. 6 Calculation method
6.1 Average whiteness value
The average whiteness value of ramie fiber is calculated according to formula (1): b,
Where: 6,—average whiteness value of the sample, degrees, br
—whiteness measurement value of each sample, degrees,
-number of times the sample is measured, n=50.
6.2 Whiteness standard deviation coefficient
The whiteness standard deviation coefficient of ramie fiber is calculated according to formula (2): Issued by the National Bureau of Standards on January 21, 1986
Implemented on October 1, 1986
GB 5885-86
Where: CV.-I—whiteness standard deviation coefficient of sample, %, ga-
whiteness standard deviation of sample, degree.
on-1Calculated according to formula (3):
6.8 Rounding of numbers
br 2 nb了
Whiteness value is taken to the first decimal place, and its standard deviation coefficient is taken to the second decimal place. (2)
Rounding of numbers is carried out according to the number rounding rules (supplement) in Appendix C of GB1.181 "General provisions for the preparation of standards in the guidelines for standardization work".
A.1 Instruments used
GB 5885-86
Appendix A
Instruments used, operation and adjustment
(reference)
The instrument applicable to this standard is the ZBD type whiteness tester. The panel structure of its whiteness tester and galvanometer is as shown in Figure 5
a Galvanometer
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b. Whiteness tester
1-shunt, 2-zero adjustment, 3 power supply, 4-binding post, 5-scale, 6-sensitivity knob, 7-zero adjustment knob, 8-coarse adjustment knob, 9-fine adjustment knob 10-key! 11-power switch, 12-indicator light, 14-digit reading knob
A.2 Operation procedure
After the instrument is adjusted, the measurement can be carried out according to the following procedure. 13—+ position reading knob:
A.2.1 Arrange the sample manually and try to make the fibers parallel and straight. A.2.2 Press down the cylinder with the index and middle fingers of your left hand, and place the sample on the cylinder with your right hand. Release your left hand, and the cylinder will pop up. Arrange the sample with both hands to make it uniform in thickness. Carefully check the mouth of the cylinder, and no light should be exposed. A.2.3 Place the sample, turn the lever 10 to the "measurement" position B, carefully adjust the tens reading knob 13 and the ones reading knob 14, so that the galvanometer light point points to "0", turn the lever back to the A position, read the whiteness value, and record it (see Appendix B for details). A.2.4 After continuous measurement for a period of time, the zero point of the galvanometer may drift. If necessary, use the working whiteness plate and black cylinder to readjust the working state of the instrument to ensure the accuracy of the measurement results. A.2.5 After the test, turn off the power switch, clean the instrument, and put on the wing cloth. A.2.6 After working for a period of time, the whiteness value of the working whiteness plate may change. It needs to be checked with a standard whiteness plate and recalibrated. A.3 Adjustment of the instrument
According to the instruction manual, the instrument should be placed in a flat, fixed and dry position. There should be no heat source or magnetic field around, and there should be no corrosive gas in the air.
Before measuring, adjust the instrument according to the following steps:A.3.1 Turn on the power switch 11. bZxz.net
A.3.2 Turn the lever 10 of the whiteness meter to the middle position A, and turn the sensitivity knob 6 counterclockwise to the bottom. The shunt 1 on the galvanometer is turned to the position of 0.01, and carefully adjust the zero adjustment knob 2 on the galvanometer panel so that the light spot points to the "0" position of the scale 5. A.3.3 Turn the sensitivity knob 6 of the whiteness meter clockwise to the bottom. A.3.4 Use the index and middle fingers of your left hand to press down the cylinder of the whiteness meter, put the working whiteness plate on it, turn the tens reading knob 13 and the ones reading knob 14 to make them the same as the whiteness value of the working whiteness plate, turn the lever 10 to the "measurement" position B, carefully adjust the coarse adjustment knob 8 and the fine adjustment knob 9, so that the galvanometer light point points to the "0" position of the scale 5, and turn the lever 10 back to the A position. 51
GB588586
A.3.5 Remove the working whiteness plate, replace it with the black cylinder, turn the tens reading knob 13 and the ones reading knob 14 on the whiteness meter to the "0" position, turn the lever 10 to the "measurement" position B, carefully adjust the zero adjustment knob 7, so that the galvanometer light point points to the "0" position of the scale 5, and turn the lever 10 back to the A position.
A.3.6 Turn the shunt 1 on the galvanometer to the 0.1 and 1 positions respectively and repeat the operations A.3.4 and A.3.5. Carefully remove the working whiteness plate and black cylinder and put them back into the spare parts box. A4 Other types of instruments that meet the technical requirements can also be used. 52
Linen fiber self-test report
Sampling date
Analysis see
Dry linen
Linen strips (balls)
Number of tests
Laboratory
GB 5885 --86
Appendix B
Tabular form
(reference)
Ram fiber whiteness test report
Laboratory number
Standard deviation coefficient, %
Combed fiber
Strips (balls)
Total average whiteness value
Standard deviation coefficient of sample self-measurement value,
B.2 Ramie fiber whiteness test record
Sampling date
Number of tests n
Dried ramie
Strips (balls)
Average whiteness value b;
Standard deviation α-!
Standard deviation coefficient
Total average value of whiteness B
Additional instructions:
GB5885—86
Ramie fiber whiteness test record
Laboratory number
Combed fiber
Ramie strips (balls)
This standard was proposed by the Ministry of Textile Industry of the People's Republic of China and is under the jurisdiction of the Standardization Research Institute of the Ministry of Textile Industry. This standard was drafted by the East China Textile Engineering Institute and was jointly drafted by Zhuzhou Ramie Textile Printing and Dyeing Factory and Shanghai No. 9 Cotton Textile Factory. The main drafters of this standard are Jiang Fanchang and Shao Kuan. 54
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