Some standard content:
National Standard of the People's Republic of China
Three-strand polyester multifilament ropes
Three-strand polyester multitilament ropes This standard adopts the international standard ISO1141-1975 "Three-strand polyester multifilament ropes". Subject content and scope of application
This standard specifies the main characteristics and markings of three-strand polyester multifilament ropes. GB/T 11787 -- 89
This standard is applicable to such ropes with a linear density of 11.8 to 6 990 ktex and a reference diameter of 4 to 96 mm. 2 Reference standards
Textile terminology (general part of textile materials and textile products) GB3291
GB4146 Textile terminology (part of chemical fibers) GB6530 Sampling and humidity conditioning for rope testing 3 Marking
Ropes should have the following markings:
"rope",
reference diameter (equivalent to the approximate diameter of the rope measured at zero tension in millimeters); variety (name of constituent materials):
number of strands;
a rope type,
reference this standard,
marking example:
a reference diameter of 30 The markings of three-strand polyester multifilament ropes with a diameter of 30 mm (linear density of 682 ktex) are as follows: Rope, 30 polyester, 3 strands, type A, GB/T117874
Rope type
Ropes are divided into three types:
Three-strand twisted rope, without rope core:
Four-strand twisted rope, with rope core,
Eight-strand braided rope, without rope core,
Three-strand polyester multifilament rope belongs to type A
Morphological diagram of three-strand rope (type A)
Approved by the State Bureau of Technical Supervision on November 6, 1989 and implemented on July 1, 1990
5 Characteristics and allowable deviations
5.1 Main characteristics
GB/T11787-89
The main characteristics of three-strand polyester multifilament ropes should be shown in the following table. Main characteristics of three-strand polyester multifilament rope
Reference diameter
Nominal value
Linear density
Note: Other grades shall be agreed upon by the buyer and seller. 92
Allowable deviation
Reference tension used for determining linear density
Nominal value
Allowable deviation
Minimum breaking strength
Superior grade
70 700
104000
123000
GB/T11787-89
The determination of linear density and breaking strength of ropes can be carried out according to the steps described in Appendix A (supplementary) or Appendix B (reference). 5.2 Other characteristics
Other characteristics involving rope constituent materials, structure and lay length shall be consistent with Appendix C (reference), or shall be agreed upon by the buyer and seller according to the needs and samples provided.
6 Marking
A blue yarn or flat wire shall be placed inside the rope to indicate that the material, properties and origin of the polyester rope are in accordance with this standard. The marking shall remain identifiable despite the infiltration and contamination of dust or liquid during use. 6.1 Rope reference diameter <12 mm:
A blue yarn or flat wire shall be woven into one strand. 6.2 Rope reference diameter ≥12 mm:
A blue flat wire at least 3 mm wide, printed with the reference to this standard and the manufacturer's mark, shall be woven into one strand. The maximum distance between two consecutive marks is 1 m. 7 Labels
Each roll of rope shall be accompanied by a label indicating the following: Constituent materials;
-Manufacturer's mark;
-Reference diameter;
Delivery length;
-Reference to this standard and its grade.
8 Packaging and delivery length
8.1 The rope should be neatly wound and firmly tied with chemical fiber ropes. The packaging of the rope should be suitable for storage and transportation without damage. When the rope is delivered by gross weight, the mass of the packaging material shall not exceed 1.5% of the gross weight of the rope. 8.2 Delivery length
Unless otherwise specified, the delivery length shall be the length measured under zero tension. The normal delivery length is 100m, 200m or 220m. The allowable deviation of the rope delivery length is:
±5% when the rope reference diameter is ≤14mm, and ±3% when the rope reference diameter is >14mm. The condition is that the total weight of the rope corresponding to the delivery length is not less than the product of the minimum linear density and the theoretical delivery length. Other lengths can be agreed upon by the buyer and seller according to special requirements. 93
A1 Principle
GB/T11787-89
Appendix, A
Test method for linear density and breaking strength of rope (supplement)
A1.1 Linear density is calculated by dividing the total weight of the sample by its length under reference tension. A1.2 Breaking strength is determined when the tension increases to the breaking point. A2 Equipment
A2.1 Balance: with appropriate range, the accuracy of measuring mass should be 1%. A2.2 Tensile strength testing machine: with appropriate range, its moving parts can be pulled at a constant speed, and the accuracy of measuring breaking strength is 1%. The following different types of clamps can be used:
Wedge clamp,
Through-eye method bollard;
Drum-disc clamp.
A3 Sampling
Sampling before the test should be carried out in accordance with the requirements specified in GB6530. To obtain accurate measurement results, the specimen should be tied at both ends before being removed from the rope package and then cut as close to the end of the tie as possible.
Unless otherwise agreed upon by the parties concerned, the specimen should be of sufficient length after being loaded on the testing machine to achieve the minimum effective length shown in Table A1 in accordance with the provisions of A5 (Figures A1, A2 and A3). Table A1 Effective length
Rope type
Reference diameter of chemical fiber rope ≥ 10 mmReference diameter of chemical fiber rope > 10 mm
Natural fiber rope
A4 Initial measurement
Testing machine type
Various types
Wedge grips or drum grips
Other types
Minimum effective length required for the test
Put a specimen of appropriate length flat on a flat surface without tension, straighten it, and measure its length. The length is expressed as Lo (unit: m) with an accuracy of 1%.
Mark two points symmetrically about the midpoint of the specimen, at least 0.5 m apart. The distance between the two points is represented by. Determine the mass of the specimen, which is expressed in m (unit: g), accurate to 0.05%. A5 Installation of the specimen on the testing machine
A5.1 Depending on the type of clamp used (wedge clamp, drum clamp or eyelet cable bollard), fix the specimen between the two clamps. The effective length Lu of the specimen must be consistent with that specified in Table A1. The effective length L should be measured under zero tension conditions. For the three main types of clamps, the specimen needs to be kept straight. When testing according to the method shown in Figure A1 and Figure A3 of GB/T 11787-89, care should be taken not to untie or unbraid the specimen before the test to cause loose strands. Sample mounted between wedge-shaped clamps Note: The limit mark "r\ of the specimen should be aligned with the jaws of the clamp. Figure A2 Eyelet splicing of the specimen between two bitts Note: ① The limit mark \r\ should be 150 mm from the end of the splicing ② When using the eyelet method bitt clamp test, a length of 250 to 300 mm should be ensured inside the eye before splicing. For chemical fiber ropes, the splicing should be properly formed. Figure A3 Sample mounted on a drum (drum-type clamp) Note: The limit mark "r\ should be at the point where the rope leaves the drum-type clamp. A5.2 The mark "" indicates a test section where the sample is installed on the testing machine. When conducting a breaking test, the rope element is usually required to break in this section.
A6" New distance between marks
The reference tension used to determine the linear density of the sample is applied to the sample, and the new distance between the two marks made on the sample during the initial measurement is measured (see Figure A2). This distance is expressed as lz. For chemical fiber rope samples with a reference diameter of ≤10 mm (minimum effective length of 400 mm), the l2 value can be measured in this way: first, place the rope sample flat on a plane, make initial marks according to the provisions of A4, and the spacing between them is not less than 0.50m. Then, the specified tension is applied by hanging a heavy hammer on a pulley, and the 12 value can be measured. Determination of breaking strength
The tension is increased by the action of the moving parts of the testing machine until the rope breaks. A7.1 Test speed
The pulling rate of the moving part of the testing machine should be constant. When the rate is expressed in millimeters per minute, its value should be within 6~95
GB/T 11787--89
10% of the effective length of the sample. For all chemical fiber ropes, the pulling rate of the moving part shall not exceed 250mm/min. A7.2 Break
In order to determine whether the test results represent the true strength of the rope, pay attention to the breaking strength and the position of the sample break. The damage to the sample caused by the clamp will seriously affect the test results. Therefore, before applying the load, install the sample according to the method of A5 and mark the sample. The break should occur between the two marks of the sample. If the break point occurs outside the mark and the breaking strength is lower than the specified value, but the recorded load is not less than 90% of the specified breaking strength, then the tensile strength of the sample can also be regarded as consistent with the regulations. Otherwise, the test is invalid and the test should be repeated.
The breaking strength value included in the report as the test result must be the value actually recorded during the test. A8 Expression of test results
A8.1 Linear density (net mass per meter)
Linear density (i.e. net mass per meter) Pi, can be obtained by formula (A1): P,
Where: m-
mass of the sample, g;
Li—length of the sample under the reference tension, m. Li can be calculated by formula (A2).
Li× Lo
Where: lo is the initial distance between the marks measured according to A4; l2-—the distance between the marks under the reference tension measured according to A6, Lo—the initial total length of the sample measured according to A4. The linear density is taken as the average value of all the samples used for the test, and the result is in grams per meter or dry tex. A8.2 Breaking strength
(Ai)
·(A2)
Express each test result in decaNewtons (daN), do not take the average but the lowest value, and indicate whether the break occurs between the marks. A9: Test report
The test report shall include the following parts: test results;
reference to this standard;
detailed test conditions (type of testing machine used, test speed), if the method described in Appendix B (reference) is used, the values used in the calculation results shall be stated;
any operating details not included in this standard, and factors that may affect the test results. Appendix B
Special procedures for determining high breaking strength
(reference)
B1 When the breaking strength of a three-ply rope made of yarns of the same material and the same linear density is greater than 30,000 daN, the following method may be used to convert the strength of the three-ply rope by measuring the breaking strength of the yarns in the rope, but the rope must meet the specified requirements in all other aspects as a prerequisite.
B2 In order to obtain the yarn required for the test, a sufficient length of rope shall be untwisted and any rotation of the individual rope components (such as yarns, strands) around their own 96
GB/T 11787-89
axial direction shall be avoided. The number of tested yarns is equal to half the value of the reference diameter (mm) of the rope. For a three-ply rope, 15 yarns shall be tested, of which 3 shall be drawn from the core.
B3 The selected yarn should be of sufficient length to provide a minimum effective length L of 250 mm. B4 The specimens are loaded on the testing machine in sequence. During this process, care must be taken to avoid untwisting of the yarn before the test. B5 In the yarn breaking test, the pulling rate of the moving part of the strength testing machine is in millimeters per minute, and its value is equal to the length of the specimen in millimeters. The breaking strength (F.) of the rope can be calculated based on the average strength measured by the extracted yarns. The calculation formula is as follows: F, F, XnXr
Where: F, - average yarn strength, daN; - total number of yarns in the rope;
- calculation coefficient (see Table B1).
Reference diameter, mm
Calculation coefficient for polyester ropes
Calculation coefficient
B6 If the breaking strength of the rope is obtained by calculation, it should be stated in the test report, commercial documents and when negotiating with the buyer. Appendix C
Material, structure, pitch and treatment of three-strand polyenzyme multifilament rope (reference)
C1The density of the polyester fiber constituting the rope is about 1.38kg/dm, and the content of titanium dioxide in the fiber is not more than 0.05%. The rope should be made of new raw materials.
C2The three-strand rope belongs to type A. Unless otherwise specified, its structural characteristics are that there is no rope core, and the rope strands are twisted in the \z” direction. These rope strands themselves are "S\. The maximum pick-up distance of the rope under the reference tension (the same tension as that used to determine the linear density) is 3.5 times the diameter of the rope. C3The rope and the rope strands should be continuous and not twisted. The number of rope yarns contained in each rope strand should be the same. When the rope strand contains a strand core, the number of strand core multifilaments contained in each rope strand should also be the same. For ropes with a reference diameter of 36 mm or more, a slight difference in the number of yarns in each strand is allowed, the difference being ±2.5% of the average number of yarns in the strand. C4 ropes should ensure structural stability. They are usually supplied in their natural state, i.e. without impregnation or coating. At the request of the buyer, the ropes may be coated or impregnated to obtain special properties. The characteristics of the coating or impregnation material shall be stated by the manufacturer. The treatment of the rope shall not reduce the breaking strength of the rope. Unless agreed upon by the buyer and the seller, the increased mass of the rope after coating or impregnation shall not exceed 5% of the mass of the rope in its natural state.
Additional Notes:
GB/T11787—89
This standard was proposed by the Ministry of Textile Industry of the People's Republic of China. This standard is under the jurisdiction of the Standardization and Chemical Research Institute of the Ministry of Textile Industry. This standard was drafted by China Textile University, in collaboration with Shanghai Textile Standard and Metrology Institute, Shanghai Wire and Belt Company, and Shanghai Cable Factory. The main drafters of this standard are Li Yongchun, Hui Yinqiu, and Zhou Xiangshu. 982 Breaking strength
(Ai)
·(A2)
Express each test result in decaNewtons (daN), do not take the average but the lowest value, and indicate whether the break occurs between the marks. A9: Test report
The test report should include the following parts: test results;
reference to this standard;
Detailed test conditions (type of testing machine used, test speed), if the method described in Appendix B (reference) is used, the values used in the calculation results should be stated;
Any operating details not included in this standard, and factors that may affect the test results. Appendix B
Special procedures for determining high breaking strength
(reference)
B1 When the breaking strength of a three-ply rope made of yarns of the same material and the same linear density is greater than 30,000 daN, the following method may be used to convert the strength of the three-ply rope by measuring the breaking strength of the yarns in the rope, but the rope must meet the specified requirements in all other aspects as a prerequisite.
B2 In order to obtain the yarn required for the test, a sufficient length of rope shall be untwisted and any rotation of the individual rope components (such as yarns, strands) around their own 96
GB/T 11787-89
axial direction shall be avoided. The number of tested yarns is equal to half the value of the reference diameter (mm) of the rope. For a three-ply rope, 15 yarns shall be tested, of which 3 shall be drawn from the core.
B3 The selected yarn should be of sufficient length to provide a minimum effective length L of 250 mm. B4 The specimens are loaded on the testing machine in sequence. During this process, care must be taken to avoid untwisting of the yarn before the test. B5 In the yarn breaking test, the pulling rate of the moving part of the strength testing machine is in millimeters per minute, and its value is equal to the length of the specimen in millimeters. The breaking strength (F.) of the rope can be calculated based on the average strength measured by the extracted yarns. The calculation formula is as follows: F, F, XnXr
Where: F, - average yarn strength, daN; - total number of yarns in the rope;
- calculation coefficient (see Table B1).
Reference diameter, mm
Calculation coefficient for polyester ropes
Calculation coefficient
B6 If the breaking strength of the rope is obtained by calculation, it should be stated in the test report, commercial documents and when negotiating with the buyer. Appendix C
Material, structure, pitch and treatment of three-strand polyenzyme multifilament rope (reference)
C1The density of the polyester fiber constituting the rope is about 1.38kg/dm, and the content of titanium dioxide in the fiber is not more than 0.05%. The rope should be made of new raw materials.
C2The three-strand rope belongs to type A. Unless otherwise specified, its structural characteristics are that there is no rope core, and the rope strands are twisted in the \z” direction. These rope strands themselves are "S\. The maximum pick-up distance of the rope under the reference tension (the same tension as that used to determine the linear density) is 3.5 times the diameter of the rope. C3The rope and the rope strands should be continuous and not twisted. The number of rope yarns contained in each rope strand should be the same. When the rope strand contains a strand core, the number of strand core multifilaments contained in each rope strand should also be the same. For ropes with a reference diameter of 36 mm or more, a slight difference in the number of yarns in each strand is allowed, the difference being ±2.5% of the average number of yarns in the strand. C4 ropes should ensure structural stability. They are usually supplied in their natural state, i.e. without impregnation or coating. At the request of the buyer, the ropes may be coated or impregnated to obtain special properties. The characteristics of the coating or impregnation material shall be stated by the manufacturer. The treatment of the rope shall not reduce the breaking strength of the rope. Unless agreed upon by the buyer and the seller, the increased mass of the rope after coating or impregnation shall not exceed 5% of the mass of the rope in its natural state.
Additional Notes:
GB/T11787—89
This standard was proposed by the Ministry of Textile Industry of the People's Republic of China. This standard is under the jurisdiction of the Standardization and Chemical Research Institute of the Ministry of Textile Industry. This standard was drafted by China Textile University, in collaboration with Shanghai Textile Standard and Metrology Institute, Shanghai Wire and Belt Company, and Shanghai Cable Factory. The main drafters of this standard are Li Yongchun, Hui Yinqiu, and Zhou Xiangshu. 982 Breaking strengthWww.bzxZ.net
(Ai)
·(A2)
Express each test result in decaNewtons (daN), do not take the average but the lowest value, and indicate whether the break occurs between the marks. A9: Test report
The test report should include the following parts: test results;
reference to this standard;
Detailed test conditions (type of testing machine used, test speed), if the method described in Appendix B (reference) is used, the values used in the calculation results should be stated;
Any operating details not included in this standard, and factors that may affect the test results. Appendix B
Special procedures for determining high breaking strength
(reference)
B1 When the breaking strength of a three-ply rope made of yarns of the same material and the same linear density is greater than 30,000 daN, the following method may be used to convert the strength of the three-ply rope by measuring the breaking strength of the yarns in the rope, but the rope must meet the specified requirements in all other aspects as a prerequisite.
B2 In order to obtain the yarn required for the test, a sufficient length of rope shall be untwisted and any rotation of the individual rope components (such as yarns, strands) around their own 96
GB/T 11787-89
axial direction shall be avoided. The number of tested yarns is equal to half the value of the reference diameter (mm) of the rope. For a three-ply rope, 15 yarns shall be tested, of which 3 shall be drawn from the core.
B3 The selected yarn should be of sufficient length to provide a minimum effective length L of 250 mm. B4 The specimens are loaded on the testing machine in sequence. During this process, care must be taken to avoid untwisting of the yarn before the test. B5 In the yarn breaking test, the pulling rate of the moving part of the strength testing machine is in millimeters per minute, and its value is equal to the length of the specimen in millimeters. The breaking strength (F.) of the rope can be calculated based on the average strength measured by the extracted yarns. The calculation formula is as follows: F, F, XnXr
Where: F, - average yarn strength, daN; - total number of yarns in the rope;
- calculation coefficient (see Table B1).
Reference diameter, mm
Calculation coefficient for polyester ropes
Calculation coefficient
B6 If the breaking strength of the rope is obtained by calculation, it should be stated in the test report, commercial documents and when negotiating with the buyer. Appendix C
Material, structure, pitch and treatment of three-strand polyenzyme multifilament rope (reference)
C1The density of the polyester fiber constituting the rope is about 1.38kg/dm, and the content of titanium dioxide in the fiber is not more than 0.05%. The rope should be made of new raw materials.
C2The three-strand rope belongs to type A. Unless otherwise specified, its structural characteristics are that there is no rope core, and the rope strands are twisted in the \z” direction. These rope strands themselves are "S\. The maximum pick-up distance of the rope under the reference tension (the same tension as that used to determine the linear density) is 3.5 times the diameter of the rope. C3The rope and the rope strands should be continuous and not twisted. The number of rope yarns contained in each rope strand should be the same. When the rope strand contains a strand core, the number of strand core multifilaments contained in each rope strand should also be the same. For ropes with a reference diameter of 36 mm or more, a slight difference in the number of yarns in each strand is allowed, the difference being ±2.5% of the average number of yarns in the strand. C4 ropes should ensure structural stability. They are usually supplied in their natural state, i.e. without impregnation or coating. At the request of the buyer, the ropes may be coated or impregnated to obtain special properties. The characteristics of the coating or impregnation material shall be stated by the manufacturer. The treatment of the rope shall not reduce the breaking strength of the rope. Unless agreed upon by the buyer and the seller, the increased mass of the rope after coating or impregnation shall not exceed 5% of the mass of the rope in its natural state.
Additional Notes:
GB/T11787—89
This standard was proposed by the Ministry of Textile Industry of the People's Republic of China. This standard is under the jurisdiction of the Standardization and Chemical Research Institute of the Ministry of Textile Industry. This standard was drafted by China Textile University, in collaboration with Shanghai Textile Standard and Metrology Institute, Shanghai Wire and Belt Company, and Shanghai Cable Factory. The main drafters of this standard are Li Yongchun, Hui Yinqiu, and Zhou Xiangshu. 98
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