Original standard number GB 5477-85 HG/T 2899-1997 Polytetrafluoroethylene material naming HG/T2899-1997 Standard download decompression password: www.bzxz.net

HG/T2899—-1997
The previous version of this standard is GB5477:-85 "Nomenclature of polytetrafluoroethylene materials". The difference from the previous version is the addition of "Foreword", "Chapter 1 Scope" and "Chapter 2 Reference Standards". Appendix B and Appendix C of the previous version already have corresponding standards, and this standard no longer lists them; Appendix D of the previous version is no longer listed in this standard because it has no practical significance; Appendix A of the previous version is still Appendix A of this standard. Appendix A is equivalent to 13.10 in ASTMD1457:1992, with appropriate modifications in the text, and "A1 Scope" and "A2 Definition" are added. Appendix A of this standard is an appendix to the standard.
From the date of implementation of this standard, the original national standard GB5477—85 "Nomenclature of polytetrafluoroethylene materials" will be abolished. This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Plastic Resin Products Sub-Technical Committee (SC4) of the National Plastic Standardization Technical Committee. The responsible drafting unit of this standard is Shanghai San Ai Fu New Materials Co., Ltd. The main drafters of this standard are Ma Yujin and Zhou Xiabao. 902
Chemical Industry Standard of the People's Republic of China
Designation of polytetrafluorocthylene materials
Designation of polytetrafluorocthylene materials This standard specifies the naming method of polytetrafluoroethylene materials. HG/T28991997
Replaces GB5477-85
This standard applies to polytetrafluoroethylene resin produced by dispersion or suspension method, including copolymers with a comonomer content of no more than 1% and polytetrafluoroethylene materials with additives, but does not include polytetrafluoroethylene dispersions. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T1844.1--1995 Plastics and resin abbreviations Part 1 Basic polymers and their characteristic properties HG/T2900-1997 Test method for bulk density of polytetrafluoroethylene resin HG/T2901-1997 Test method for particle size of polytetrafluoroethylene resin 3 Naming method
The naming method of polytetrafluoroethylene materials is: fixed name + model. 3.1 Fixed name
According to the provisions of GB/T1844.1, the abbreviation code of polytetrafluoroethylene PTFE is used. 3.2 Model
The model consists of the following 6 items, which are represented by English letters and Arabic numerals respectively: Polymerization method
-Processing method
Extrusion pressure
Average particle size
Bulk density
Additives
3.3 Item code
The item codes in the polytetrafluoroethylene material model are shown in Table 1. Approved by the Ministry of Chemical Industry of the People's Republic of China on May 23, 1997 and implemented on October 1, 1997
Polymerization method
Suspension polymerization
Dispersion polymerization
Processing method
HG/T 2899-1997
Project code of polytetrafluoroethylene materials
Extrusion pressure
13.8~34. 4**
*) Tested under the condition of molding ratio of 100:1, **) Tested under the condition of molding ratio of 400:1. **) Tested under the condition of molding ratio of 1600:1. 3.3.1 Pigments are indicated by the Chinese name of the color. Characteristic
Average particle size
3.3.2 Fillers are indicated by their mass percentage and name abbreviation code. 4 Naming examples
Volume density
10~100
101～300
301700
601～800
Additives
This color material is not indicated Filler:
GF glass fiber
Br Bronze
Mo—Molybdenum disulfide
Carbon fiber
The red polytetrafluoroethylene material produced by suspension polymerization, suitable for molding processing, with an average particle size of 31μm and a volume density of 350g/L, should be named: PTFESM021--Red
The polytetrafluoroethylene resin produced by dispersion polymerization, with an extrusion pressure of 25MPa, an average particle size of 550μm, and a volume density of 580g/L, without any additives, should be named: PTFEDE2414.3 Example 3
The polytetrafluoroethylene material produced by suspension polymerization, suitable for molding processing, with an average particle size of 27μm, a volume density of 380g/L, and containing 25% glass fiber, should be named: PTFESM02125GF5 Test method
5.1 Determination of extrusion pressure
The method specified in Appendix A shall be used.
5.2 Determination of average particle size
Perform according to the provisions of HG/T 2901.
5.3 Determination of bulk density
Perform according to the provisions of HG/T2900.
A1 Scope
HG/T 2899-1997
Appendix A
(Standard Appendix)
Determination of extrusion pressure of polytetrafluoroethylene resin This appendix is ​​applicable to the determination of extrusion pressure of polytetrafluoroethylene resin produced by dispersion polymerization. A2 Definition
This standard adopts the following definitions:
Extrusion pressure
Refers to the pressure measured when the dispersed resin with lubricant is extruded under a certain molding ratio. Molding ratio
Refers to the ratio of the projected area of ​​the cross section of the preform to the cross section of the die. A3 Equipment
A3.1 Paste extruder
The paste extruder is shown in Figure A1.
1-speed box; 2, 3-motor; 4-pump; 5-storage; 6-safety valve, 7-high speed valve; 8-low speed valve; 9-piston; 10-hydraulic cylinder, 11-pressure probe, 12-piston column, 13-die: 14-pump Figure A1 Schematic diagram of paste extruder
The inner diameter of the vertical paste extruder cylinder is 31.8mm and the length is about 305mm. The lower part has a detachable die. The outer diameter of the extruder piston is 31.6mm. The extruder is equipped with a sensor and a recorder to record the pressure on the piston surface. The pressure range of the sensor is greater than 69MPa, and the hydraulic system is used to drive the piston to move at a certain rate, that is, the extrusion rate of dry resin is 19g/min (the extrusion rate of resin containing lubricant is 23.5g/min).
A3.2 Extruder die
The extruder die is shown in Figure A2.
HG/T 2899—1997
Figure A2 Extruder die
The internal angle of the die is 30°, and the molding ratio is shown in Table A1. Table A1 Die size
Ring ratio
160011
A3.3 Other test instruments and equipment
Inner diameter of molding hole, mmwww.bzxz.net
Weighing, mixing, resin preforming and cleaning of extruder. A4 Procedure
A4.1 Mixing
A4.1.1 Use a sieve with a pore size of 2.5 mm 1\) to sieve the dry resin on a clean, dry, smooth paper. Length of molding section, mm
A4.1.2Put 200g±0.5g of sieved dry resin into a clean, dry glass container with good airtightness (about 1L container).
A4.1.3Add 47.6g±0.1g of No. 200 gasoline into the glass jar, and pay attention that the lubricant should not wet the wall, otherwise it will hinder the mixing process. Shake the jar briefly to make the lubricant not stick to the wall as much as possible. Instructions for use:
1) ASTMD1457 stipulates that the aperture is 4 mesh sieve. 906
HG/T 2899—1997
A4.1.4Put the jar on the roller of a rubber-covered roller and roll it at a rate of 30r/min for 25min±5min. A4.1.5 After mixing, place the can and the material in a controlled environment at 30°C ± 1°C for at least 2 hours (a water bath can meet this requirement). A4.2 Preforming
Resin preforming is done by using a preforming die with an inner diameter of 31.8 mm and a length of 610 mm. The resin containing lubricant is added into the preforming die through a funnel, and a hydraulically controlled plug rod is used to apply a slow and uniform pressure to the resin. The pressure is at least 0.69 MPa. After maintaining the pressure for 1 min to 2 min, the preform is removed from the preforming die, and the preform is loaded into the extruder barrel and installed on the die. The barrel and die temperature are controlled at 30°C ± 1°C.
A4.3 Extrusion pressure measurement
A4.3.1 Use the fast gear to operate the piston to pressurize the barrel. When the material is extruded from the molding port of the die, change to the slow gear and start the pressure recording system. The extrusion rate is 23.5g/min.
A4.3.2 Record the surface pressure of the piston in the barrel and the resin every minute. The extrusion pressure refers to the average pressure measured when the sample is extruded in the third and fourth minutes. At this time, the extrudate should be continuous and smooth. 907
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