GB/T 21032-2026Polyamide monofilament (English PDF)

4.1 Classification

4.1.1 Polyamide monofilaments can be classified according to their applications as follows:

---Polyamide monofilament for fishing net weaving (hereinafter referred to as fishing net yarn);

---Polyamide monofilament for fishing (hereinafter referred to as fishing line).

4.1.2 According to their physical and mechanical properties, fishing lines can be divided into.

7.8 grade (the breaking strength of a

1.0 fishing line is 17.8N);

---Fd122.2 grade (the breaking strength of a

1.0 fishing line is 22.2N);

---Fd126.7 grade (the breaking strength of a fishing line with a gauge of

Note. We can produce fishing lines with physical and mechanical properties no lower than Fd117.8 according to user, contract and other requirements.

4.2.1 Fishing net wire

4.2.1.1 Complete Markup Complete markings for fishing net wire are indicated as follows:

4.2.1.2 Simplified labeling Fishing net wire is marked in the following way.

4.2.2.1 Complete Markup

4.2.2.2 Simplified labeling Fishing line markings are indicated as follows:

5.2 Physical and mechanical properties

5.2.1 Fishing net wire The physical and mechanical properties of fishing net wire should meet the requirements of Table

2.For fishing net wire specifications not listed in Table 2, the physical and mechanical properties should be determined according to formula (1). The calculations are performed using formulas (2) and (3), and the results are retained to three significant figures. The allowable deviation of linear density is based on the specifications of the adjacent smaller diameter.

5.2.2 Fishing line

5.2.2.1 Diameter and Deviation The diameter and tolerance of fishing line should conform to the specifications in Table

3.For nominal diameters of fishing lines not listed in Table 3, the calculation should be performed according to formula (4). Calculate, and retain three significant figures for the result.

5.2.2.2 Linear Density The line density of the fishing line should not be less than the calculated value of formula (1), and the calculation result should be retained to 3 significant figures.

5.2.2.3 Fracture Strength 5.2.2.3.1 The breaking strength (FdF1) of a

1.0 fishing line shall not be less than

17.8 N. 5.2.2.3.2 The breaking strength of the fishing line should not be less than the calculated value of formula (5), and the calculation result should be retained to 3 significant figures. 5.2.2.3.3 The coefficient of variation of the breaking strength of fishing line shall conform to the provisions of Table 5.

5.2.2.4 Strength of a single-strand knot The strength of a single knot in a fishing line should not be less than the calculated value of formula (6), and the calculation result should be retained to 3 significant figures.

5.2.2.5 Elongation at break The breaking elongation of fishing line should meet the requirements of Table 7.

5.3 Moisture regain At the time of delivery, the standard moisture regain of the polyamide monofilament is 4.5% ± 0.5%.

6.2.1 Test Conditions

6.2.1.1 Conditioning and Testing Atmosphere Perform in accordance with the provisions of GB/T 6529.

6.2.1.2 Pre-tension Perform in accordance with the provisions of GB/T 6965.

6.2.2 Diameter Measurement Use an outside micrometer with a minimum reading of no more than 1 µm for measurement. The distance between any three points should be greater than 1 m. Take measurements at any three points. Its arithmetic mean.

6.2.3 Linear density determination The linear density test procedure is as follows:

a) Under pre-tension, cut 20 specimens of (1000±1) mm;

b) Weigh the sample (m) using an analytical balance with a sensitivity of no more than

0.1 mg;

c) Calculate the linear density of the polyamide monofilament sample according to formula (7), and retain 3 significant figures in the calculation result.

6.2.4 Determination of breaking strength and elongation at break Breaking strength and elongation at break were measured using a strength testing machine with an accuracy class of no more than 1.0%. The test procedures are as follows:

a) Set the strength testing machine to an upper and lower clamp distance of (500±1) mm and a tensile speed of 300 mm/min; when using other upper and lower clamps... When specifying the distance between the mouth and the mouth, please describe it in the report;

b) Under pre-tension, clamp the specimen in a strength testing machine and stretch it until it breaks (the specimen breaks at the clamps or slips in the fixture). (If the test value is invalid), record the load and displacement at the time of specimen fracture. The load at the time of fracture is the fracture strength.

c) Calculate the elongation at break of the polyamide monofilament sample according to formula (8), and retain the result to one decimal place;

d) Calculate the coefficient of variation of the breaking strength of the polyamide monofilament sample according to formula (9), and keep the calculation result to one decimal place.

6.2.5 Determination of Single-Strand Knot Strength Set the test parameters of the strength testing machine according to the provisions of 6.2.4a). After the sample is knotted, it is clamped in a strength testing machine under pre-tension, with the knot approximately in the middle of the upper and lower clamps, and stretched to... The load at which the specimen breaks (test values are invalid if the specimen does not break at the knot) is recorded. The load at which the specimen breaks is the single-strand knot strength.

7.2 Batching and Sampling

7.2.1 A batch of 5 tons of products made of the same materials, with the same specifications, and manufactured through the same process constitutes one inspection batch. A batch of products weighing less than 5 tons also constitutes one inspection batch.

7.2.2 Five samples shall be randomly selected from each batch of products for inspection.

7.3 Factory Inspection

7.3.1 Each batch of products must undergo factory inspection by the factory inspection department before leaving the factory. Only products that pass the inspection and are accompanied by a certificate of conformity can be shipped out.

7.3.2 The factory inspection items are as follows:

---The factory inspection items for fishing net wire include appearance quality, linear density, breaking strength, and single-strand knot strength;

---The factory inspection items for fishing lines are appearance quality, line density, and breaking strength.

7.4 Type Testing

7.4.1 Under normal circumstances, type testing should be conducted at least once a year. Type testing should be conducted under any of the following circumstances.

---When production resumes after a long period of shutdown;

---When new products are being trial-produced, type-approved, or when existing products are being transferred to another factory for production;

---When there are significant changes in raw materials or processes that may affect product performance;

---When users or national quality management departments request type testing.

7.4.2 The type test items are all the relevant items in Chapter 5.

7.5 Judgment Rules The following rules shall be followed for determination.

---If all test items of the inspected sample meet the requirements, the sample product is deemed qualified;

---If any one of the test items of an inspected sample fails to meet the requirements, the sample shall be deemed unqualified;

---If all samples pass the test, the batch of products is deemed (qualified/compliant).

---If any single sample fails to meet the standard, the entire batch of products is deemed unqualified.