HG/T 2757-1996 Determination of the reactivity of phenolic resin on the B-stage transformation test plate HG/T2757-1996 standard download decompression password: www.bzxz.net

HG /T 2757—1996
This standard is equivalent to ISO 8987:1988 "Determination of the Reactivity of Plastic-Phenolic Resin on the B-stage Transformation Test Plate". This standard is consistent with ISO8987 in terms of technical content and writing format. The main differences between this standard and ISO8987 are: The instrument used in this method is designed and manufactured according to the parameters specified in ISO8987, and the accuracy is consistent with IS8987. 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 Product Branch of the National Plastic Standardization Technical Committee: The drafting unit of this standard: Shandong Chemical Plant. The main drafters of this standard: Yin Jianxun, Cadmium Xiuhua, 21
ISo former
The International Organization for Standardization (ISO) is a joint organization of national standard groups (IS member groups) worldwide. The work of formulating national standards is carried out by ISO technical committees. Any member group that is interested in a project determined by a technical committee has the right to send representatives to participate in the technical committee. Governmental or non-governmental international organizations can also participate in this work by contacting ISO. ISO and the International Electrotechnical Commission (IEC) work closely together on all topics of electrotechnical standardization. The draft international standards adopted by the technical committees are distributed to member groups for voting opinions before being accepted as international standards by the ISO Council. According to ISO working procedures, at least 75% of the member groups should vote in favor for the vote to be effective. International standard ISO 8987 was formulated by ISO/TC 61 Plastics Technical Committee. 22
Chemical Industry Standard of the People's Republic of China
Determination of Reactivity of Phenolic Resin on B-Stage Transition Test Plate
HG/ T 2757 —1996
eqr ISO 8987 : 1988
This standard specifies the method for determining the B-stage transition time of phenolic resin on a heating plate at a certain temperature and conditions. This standard describes the test method using two different test plates. Method A is a spherical test plate method, and method B is a non-concave flat test plate method.
2. Principle
On a test plate using one of two methods (depending on the method), the phenolic resin is condensed to the B stage. 3A method is measured on a concave test plate
3.1 Apparatus
3.1.1 Constant temperature control device, allowing a temperature variation of ±0.53.1.2 Heating plate. The test plate can be fixed on the heating plate in an appropriate manner to obtain the best heat transfer effect. Note: If a test plate with a heater is used, the heater is unnecessary. 3.1.3 Glass drop with a diameter of 5 mm and a diameter reduced to 2 mm at one end3.1.4 Balance with a sensitivity of 0.01 g
3.1.5 Syringe.
3. 1.6 Stopwatch with a division of at least 1 s.
3.1.7 The B-stage transformation test plate has a concave surface as shown in Figure 1 with or without a heater. Approved by the Ministry of Chemical Industry of the People's Republic of China on April 15, 1996 and implemented on January 1, 1997
3.2 Number of samples
HG/T2757-1996
1-Holes for constant temperature control and measurement of the sensor; 2-Socket for the overflow meter; 3-Metal display tube for the thermometer Figure 1 B-stage transformation test plate
According to the requirements of the corresponding standards or as agreed upon by the relevant parties, one or more tests can be carried out. 3.3 Operation steps
Heat the B-stage conversion test plate to the desired temperature, allowing the temperature to vary within the range of ±0.5°C. Put on a cover with one side open to surround the test plate to protect it from wind. Pour 0.5g±0.05g of phenolic resin into the concave surface of the test plate. Liquid resin or resin solution can be injected into the concave surface with a syringe. Start the stopwatch when the resin contacts the test plate. Use a glass to make a short circular motion from the edge of the concave surface to the middle to stir the resin.
For those with longer B-stage transition time, stir for 1 minute first, then stir for 10 seconds every 1 minute. If the B-stage transition point is reached within 1 minute intervals, repeat the test to get the approximate test time. When the test is near the end and the resin becomes viscous, stir the resin continuously and lift the glass handle slightly to check whether it forms fibers. When the glass is lifted and the resin does not form long fibers but interrupts into a rubber-like substance, stop the stopwatch and report the time in minutes and seconds. 4B method is used to measure on a flat plate without concave surfaceswwW.bzxz.Net
4.1.1 The constant temperature control device allows a temperature variation of ±0.5t4.1.2 Heating plate The test plate can be fixed on the heating plate in an appropriate manner to obtain the best heat transfer effect. Note: If a test plate with a heater is used, the heater is unnecessary. 4.1.3 Scraper about 10 cm long and 1.25 cm wide, 4.1.4 Balance with a sensitivity of 0.01 g-
4. 1. 5 Syringe,
HG/T 2757 — 1996
4.1.6 Stopwatch with a division of at least 1 s.
4.1.7 B-stage transformation test plate with a size of about 15 cm × 15 cm × 2 cm, with a hard chrome-plated surface and equipped with a thermometer socket, with or without a heater.
4. 2 Number of tests
One or more tests may be conducted according to the requirements of the relevant standards or as agreed upon by the parties concerned. 4.3 Operating steps
Heat the hot plate to the required temperature and allow the temperature to vary within the range of ±0.5°C. Pour 0.5±0.05g of phenolic resin on the test plate. If the resin is in powder form, make a small pile of about 1cm high at one end of the scraper. If it is a solid or solution, inject it onto the test plate with a syringe. Start the stopwatch when the resin contacts the test plate. Distribute the resin evenly over an area of ​​4cm×7.5cm as quickly as possible. Stir the resin with the flat surface of the scraper, keeping the front edge of the scraper slightly tilted upward and applying light pressure. Stir the resin at a speed of once every 3s. After reaching the end, turn the direction again. Do not let the scraper completely leave the resin until the test is completed. Continue to stir the resin until the curing characteristics appear, that is, the resin cannot be stirred and becomes rubbery, or suddenly becomes hard. At this time, stop the stopwatch and record the required time in minutes and seconds. Scrape off the cured resin on the test board, avoid scratching the surface of the test board, 5 Accuracy
Repeatability: ±4%
Reproducibility: ±10%
6 Test report
The test report should include the following:
Indicate the industry standard and the method used (A method or B method): Test board temperature:
B-stage transition time (single value or average value) 25
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