GB/T 18146.3-2015 English PDF (GBT18146.3-2015)

This part of GB/T 18146 specifies the definition, technical requirements, sampling quantity and sampling methods, test methods, inspection rules, packaging, marking, transportation, and storage of cotton type hemp fibers. This part applies to the quality assessment of cotton type hemp fibers.

GB/T 18146.3-2015
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 59.060.10
B 32
Replace GB/T 18146.3-2000
Hemp fiber - Part 3: Cotton type hemp fiber
大麻纤维
ISSUED ON: JULY 3, 2015
IMPLEMENTED ON: OCTOBER 1, 2015
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 Technical requirements ... 5
5 Sampling quantity and sampling method ... 5
6 Test methods ... 6
7 Quality assessment ... 8
8 Handover and acceptance ... 8
9 Packaging, marking, transportation, and storage ... 9
Foreword
GB/T 18146 “Hemp fiber” is divided into 3 parts:
--- Part 1: Raw white degummed hemp;
--- Part 2: Raw white hemp sliver;
--- Part 3: Cotton type hemp fiber.
This part is Part 3 of GB/T 18146.
This part is drafted in accordance with the rules given in GB/T 1.1-2009. This part replaces GB/T 18146.3-2000 “Hemp fibre - Part 3: Raw white hemp noil”. Compared with GB/T 18146.3-2000, the main technical changes are as follows: --- The standard name is changed from “Hemp fibre - Part 3: Raw white hemp noil” to “Hemp fiber - Part 3: Cotton type hemp fiber”;
--- The scope is modified and changed from “applicable to raw white hemp noil” to “applicable to the quality assessment of cotton type hemp fibers”;
--- GB/T 18146.1 is deleted from the normative references;
--- The definition of “cotton type hemp fiber” is added;
--- The “hemp Micronaire” is canceled and replaced by the “fineness”;
--- The technical requirements for cotton type hemp fibers are modified; --- The sampling quantity and sampling method are modified.
This standard is proposed by and shall be under the jurisdiction of China Fiber Inspection Bureau.
Drafting organizations of this part: Quartermaster Equipment Research Institute of the General Logistics Department, China-Hemp Industrial Investment Co., Ltd., Yunnan Fiber Inspection Bureau.
The main drafters of this part: Hao Xinmin, Gao Mingzhai, Liang Ning, Zhao Jun, Tao Ran, Yang Yuan.
The previous versions of the standards replaced by this part are as follows: --- GB/T 18146.3-2000.
Hemp fiber - Part 3: Cotton type hemp fiber
1 Scope
This part of GB/T 18146 specifies the definition, technical requirements, sampling quantity and sampling methods, test methods, inspection rules, packaging, marking, transportation, and storage of cotton type hemp fibers.
This part applies to the quality assessment of cotton type hemp fibers. 2 Normative references
The following documents are essential to the application of this document. For the dated documents, only the versions with the dates indicated are applicable to this document; for the undated documents, only the latest version (including all the amendments) is applicable to this standard.
GB/T 8170 Rules of rounding off for numerical values & expression and judgment of limiting values
GB/T 9995 Determination of moisture content and moisture regain of textile - Oven- drying method
GB/T 18147.1 Test method for hemp fibre - Part 1: Test method for oil content of hemp fibre
GB/T 18147.3 Test method for hemp fiber - Part 3: Test method for length of hemp fiber
GB/T 18147.4 Test method for hemp fiber - Part 4: Test method for fineness of hemp fiber
GB/T 18147.5 Test method for hemp fiber - Part 5: Test method for breaking strength of hemp fiber
GB/T 18147.6 Test method for hemp fiber - Part 6: Test method for defect in hemp fiber
3 Terms and definitions
The following terms and definitions apply to this document.
The sampling quantity is determined by the number of pieces in each batch. If the number of pieces is 2 or less in each batch, take 1 piece; if it is 5 or less in each batch, take 2 pieces; if it is 10 or less in each batch, take 3 pieces; if it is 25 or less in each batch, take 4 pieces, if it is 350 or less in each batch, take 5 pieces; if it is 350 or more in each batch, take 6 pieces.
5.2 Sampling method
5.2.1 Single-piece sampling
5.2.1.1 Sampling for moisture regain test: Take about 50 g from each sample in the batch (sampling depth shall be 10 m~15 cm from the outer layer of the sack), and immediately put them into an airtight container for moisture regain test. 5.2.1.2 Sampling for appearance quality inspection: Take about 100 g from each sample in the batch (sampling depth shall be 10 cm~15 cm from the outer layer of the sack), and place them flat on the workbench for appearance quality inspection. 5.2.1.3 Fully mix the samples after appearance quality inspection to form laboratory samples for test sampling:
a) Sampling for oil content test: Take 3 samples, each about 5 g, and measure the oil content.
b) Sampling for length test: Take 3 samples, each about 150 mg, and measure the fiber length.
c) Sampling for fineness test: Take 3 samples, each about 300 mg, and measure the fineness.
d) Sampling for breaking strength test: Take 12 samples, each about 5 mg, and measure the breaking strength.
e) Sampling for the nep and strip fiber test: Take 3 samples, each about 1 g, and measure the nep and the content of strip fiber.
5.2.2 Batch sampling
For multiple pieces of a batch, according to the provisions of 5.2.1, take a sample from each piece and test respectively, and take the arithmetic mean of the test data as the test result of the batch.
6 Test methods
6.1 Moisture regain
Through visual inspection and touch by hand, determine that there is no obvious abnormality in the moisture regain of the hemp fibers, and then carry out the test according to GB/T 9995.
6.2 Appearance quality
Under the conditions of northerly daylight or simulated daylight (illuminance ≥600 lx), inspect the appearance by eyes.
6.3 Oil content
The test shall be carried out according to GB/T 18147.1.
6.4 Average length, short fiber content
The test shall be carried out according to GB/T 18147.3.
6.5 Fineness
The test shall be carried out according to GB/T 18147.4.
6.6 Breaking strength
The test shall be carried out according to GB/T 18147.5.
6.7 Nep and strip fiber content
The test shall be carried out according to GB/T 18147.6.
6.8 Conditioned weight
6.8.1 The inspection of the conditioned weight is based on batches. Weigh each batch and record the gross weight.
6.8.2 According to the batch size, and the sampling quantity specified in 5.1, weigh the mass of the packaging, calculate the average mass of a single packaging, and round the calculation result to two decimal places.
6.8.3 The net weight of each batch of hemp fiber shall be calculated according to formula (1), and the result shall be rounded to three decimal places.
Where:
W2 --- Net weight, in tons (t);