GB/T 20944.2-2007 PDF English
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Textiles - Evaluation for antibacterial activity - Part 2: Absorption method
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GB/T 20944.2-2007: Textiles - Evaluation for antibacterial activity - Part 2: Absorption method---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GBT20944.2-2007
GB
NATIONAL STANDARD OF THE
PEOPLE'S REPUBLIC OF CHINA
ICS 59.080.30
W 04
Textiles - Evaluation for antibacterial activity - Part 2.
Absorption method
Issued on. JUNE 14, 2007
Implemented on. JANUARY 01, 2008
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine of PRC;
Standardization Administration of PRC.
Table of Contents
Foreword... 3
1 Scope... 4
2 Normative references... 4
3 Terms and definitions... 4
4 Safety precautions... 5
5 Principles... 5
6 Devices... 5
7 Culture medium and reagents... 6
8 Test bacteria... 8
9 Cultivation and preparation of test bacterial liquid... 9
10 Preparation of specimen... 10
11 Test procedure... 11
12 Calculation and evaluation of results... 12
13 Test report... 13
Foreword
GB/T 20944 "Textiles - Evaluation for antibacterial activity" includes the
following three parts.
- Part 1.Agar diffusion plate method;
- Part 2.Absorption method;
- Part 3.Shake flask method.
This part is Part 2 of GB/T 20944.
The test method in this part refers to the absorption method, in the international
standard draft ISO/DIS 20743.2005 "Textiles - Determination of antibacterial
activity of textile products".
This part was proposed by China Textile Industry Association.
This part shall be under the jurisdiction of the Basic Branch of the National
Textile Standardization Technical Committee (SAC/TC 209/SC 1).
The main drafting organizations of this part. National Cotton Textile Product
Quality Supervision and Inspection Center, Shenzhen Beiyue Haiwei Chemical
Co., Ltd., Beijing Jiershuang High-tech Co., Ltd., Bosideng Co., Ltd., Jiangsu
AB Group Co., Ltd., Southern Testing Center of Shanghai Textile Science
Research Institute, Suzhou Fiber Inspection Institute and Textile Industry
Standardization Institute.
The main drafters of this part. Zheng Yuying, Shang Chengjie, Zou Haiqing,
Gao Dekang, Zhang Hua, Jiang Jianying, Liu Chen, Xue Zhengyuan.
Textiles - Evaluation for antibacterial activity - Part 2.
Absorption method
1 Scope
This part of GB/T 20944 specifies the quantitative test and evaluation method,
for the determination of the antibacterial activity of textiles, by the absorption
method.
This part applies to various textile products, such as down, fibers, yarns, fabrics
and their products.
This part does not involve the evaluation of the safety of antibacterial products.
2 Normative references
The provisions in following documents become the provisions of this part
through reference in this part of GB/T 20944.For the dated references, the
subsequent amendments (excluding corrections) or revisions do not apply to
this part; however, parties who reach an agreement based on this part are
encouraged to study if the latest versions of these documents are applicable.
For undated references, the latest edition of the referenced document applies.
GB/T 12490-1990 Textiles - Testing method for color fastness to domestic
and commercial laundering
3 Terms and definitions
The following terms and definitions apply to this part of GB/T 20944.
3.1
Antibacterial activity
The performance of product to inhibit the reproduction of bacteria.
3.2
Control fabric
A 100% cotton fabric, which does not subject to any treatment, is used to
verify the growth conditions of the test bacteria.
4 Safety precautions
This method requires the use of bacteria AND has the conditions to promote
the reproduction of bacteria.
5 Principles
The specimen and the control fabric are respectively inoculated with the test
bacteria solution.
6 Devices
6.1 Spectrophotometer. Detection wavelength 660 nm.
6.2 Constant temperature incubator. The temperature can be maintained at
37 °C ± 2 °C.
6.3 Water bath. The temperature can be maintained at 45 °C ± 2 °C.
6.4 Constant temperature speed-regulating shaker cabinet.
6.8 Glass or styrene plates. Diameter 90 mm ~ 100 mm or 55 mm ~ 60 mm.
6.9 Vortex oscillator.
6.10 Two-stage biological safety cabinet.
6.11 Test tubes, flasks and other commonly used laboratory utensils.
7 Culture medium and reagents
The reagents used in the test shall be analytically pure or suitable for
microbiological tests.
7.1 Soy protein broth (TSB)
7.4 SCDLP liquid medium
7.5 Diluent
8 Test bacteria
8.1 Strains
The following Gram-positive and one of the Gram-negative strains shall be used.
8.2 Activation of freeze-dried bacteria
The freeze-dried bacteria are thawed and dispersed in 5 mL of TSB (7.1) into a
suspension state. It is cultured at 37 °C ± 2 °C for 18 h ~ 24 h.
8.3 Identification
The following information shall be marked for each test bacteria.
9 Cultivation and preparation of test bacterial liquid
9.1 Culture A
Use the inoculation loop to take the preserved bacteria (8.2). Inoculate the EA
(7.6) plate by the line-marking method. Incubate at 37 °C ± 2 °C for 24 h ~ 2 h.
Note. The plate is stored under the condition of 5 °C ~ 10 °C AND used within 1 week.
9.3 Culture C
Take 20 mL of broth NB (7.3) or TSB (7.1), into a 100 mL conical flask. Take 0.4
mL of bacterial solution from culture B (9.2) AND add it to the flask for culture.
The concentration of the cultured bacteria is 107 CFU/mL.
9.4 Preparation of test bacterial solution
Use water to dilute the broth NB (7.3) 20 times. Adjust the bacterial
concentration of culture C (9.3) to 1 x 105 CFU/mL ~ 3 x 105 CFU/mL, which is
used as the test bacterial solution.
10 Preparation of specimen
10.1 Sample washing
If evaluating the antibacterial and washing resistance performance, take 3 small
samples from each large sample (each size is 10 cm x 10 cm; cut into 2 pieces).
Wash it, according to the test condition A1M in GB/T 12490-1990.Use the ECE
standard detergent.
10.2 Specimen mass
Select a representative specimen from each sample. Cut it to an appropriate
size. Weigh 0.40 g ± 0.05 g as a specimen. Take 3 specimens for the test of
antibacterial activity, AND 6 control fabrics, respectively.
10.3 Placement of specimen
Place each specimen in a small glass bottle.
10.4 Sterilization of specimen
Choose the sterilization method according to the fiber and treatment type of the
specimen. Generally, autoclave sterilization is used.
11 Test procedure
11.1 Inoculation of specimen
Respectively pipette accurately 0.2 mL of the test bacterial solution (9.4);
inoculate it to the specimen (10.3 or 10.4) in each vial. Ensure that the bacterial
solution does not stick to the wall of the vial. Apply the cap tightly.
Note. In order to immerse the bacterial solution on the specimen, a test bacterial
solution, which contains 0.05% non-ionic surfactant, can also be used. However, it
shall be indicated in the test report.
11.2 Elution immediately after inoculation
Add 20 mL of SCDLP medium (7.4), into the 3 control fabric vials (11.1), which
had been inoculated with the test bacteria solution. Close the cap tightly. Use
hands to shake it for 30 s (swing about 30 cm). OR otherwise use a shaker to
shake 5 times (5 s each time), to wash off the bacteria.
11.3 Cultivation
Culture the remaining 6 vials (3 control fabrics and 3 specimens), which had
been inoculated with the test bacteria solution, at 37 °C ± 2 °C for 18 h ~ 24 h.
11.4 Elution after cultivation
After culture (11.3), add 20 mL of SCDLP medium (7.4) to each vial. Close the
cap tightly. Use hands to shake it for 30 s (swing about 30 cm). OR otherwise
use a shaker to shake it 5 times (5 s each time), to wash off the bacteria.
......
Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al.
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