GB/T 34784-2017Refined flax (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This standard was proposed by the China Fibre Inspection Bureau and is under the administration of the National Technical Committee on Fibre Standardization (SAC/TC 513).

The organisations responsible for drafting this standard are Donghua University, Shenzhen Beilishuang Industrial Co. Ltd., the China Fibre Inspection Bureau, Tongxiang Xianzhi Fibre Co. Ltd. and the Heilongjiang Provincial Fibre Inspection Bureau.

1 Scope

China's national standard for refined flax, the long bast fibre that has been processed until it splits down into fibres fine enough to be spun on cotton or wool machinery rather than on dedicated flax equipment. The whole commercial value of the material lies in how far that splitting has been carried, and the standard makes it measurable: it defines splitting as the degree to which the flax fibre has been divided, expressed in metric count, and it reserves the name refined flax for fibre that reaches 2000 Nm or better. On that basis it sorts the material into three classes and, within each class, into first, second and third grade using fibre length, the proportion of short fibre, breaking tenacity, the proportion of unseparated fibres, the impurity content and whiteness. A buyer and a seller who both quote this standard are therefore quoting the same thing, which is why the document also fixes the sampling, the test methods, the inspection rules and the requirements for packaging, marking, transport and storage. The commercial moisture regain is set at 12.0 per cent. It applies to refined flax.

This standard specifies the terms and definitions, the quality requirements, the sampling and test methods, the inspection rules and the packaging, marking, transport and storage of refined flax.

This standard applies to refined flax.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 5885 Test method for whiteness of ramie fibre

GB/T 6529 Textiles - Standard atmospheres for conditioning and testing

GB/T 8170 Rules of rounding off for numerical values and expression and judgement of limiting values

GB/T 9995 Determination of moisture content and moisture regain of textiles - Oven-drying method

3 Terms and definitions

The following terms and definitions apply to this document.

3.1 splitting: the degree to which the flax fibre has been split, expressed as a metric count.

3.2 refined flax: flax fibre which, after treatment, reaches a splitting of 2000 Nm or above.

3.3 unseperated fibers: an aggregate of a number of single fibres stuck together by gum.

3.4 short flax fiber: fibre with a length of 16 mm or less.

3.5 impurity: non-fibrous matter other than flax fibre, such as shive, weeds and dust.

4 Quality requirements

4.1 Refined flax is divided into three classes according to the splitting of the fibre: class one, 3000 Nm and above; class two, splitting greater than or equal to 2500 Nm and less than 3000 Nm; class three, splitting greater than or equal to 2000 Nm and less than 2500 Nm.

4.2 Refined flax is graded according to the quality indexes of fibre length, proportion of short fibre, breaking tenacity, proportion of unseparated fibres, impurity content and whiteness. It is divided into first, second and third grade; material below third grade is off-grade. The quality requirements are given in Table 1.

4.3 The grade is determined on the basis of the quality requirements specified in 4.2, taking the lowest of the individual items.

4.4 The commercial moisture regain of refined flax is 12.0 per cent.

5 Sampling

Sampling shall be carried out in accordance with A.2 of Annex A.

6 Test methods

The tests shall be carried out as specified in A.3 of Annex A.

7 Inspection rules

7.1 The producer of refined flax shall inspect the product batch by batch in accordance with the standard and shall supply the results of the product inspection.

7.2 The acceptance inspection shall be carried out on one and the same batch number and is limited to refined flax which the consignee has not yet unpacked and used.

7.3 Where either party to the transaction objects to the inspection result, a re-inspection may be applied for.

8 Packaging, marking, transport and storage

8.1 Packaging: the packaging of refined flax shall ensure that the quality of the product does not deteriorate and shall be convenient for transport and storage. The outer packaging material shall be of cotton or of hemp.

8.2 Marking: the packaging of the product shall carry a clear product mark; the mark shall be unambiguous and legible. Its content includes the name of the manufacturer, the variety, the class, the grade, the standard applied (the number of this standard), the batch number, the package number and the date of production.

8.3 Transport: during transport the product shall be protected from loss and kept safe and secure; batches shall not be mixed, and the product shall be protected from fire and from damp.

8.4 Storage: in storage the product shall be protected from damp, from fire and from mould.