This standard specifies the sample preparation, sample state and test standard environment for the performance test of resin castings. This standard is applicable to castings of resins for fiber reinforced plastics and special casting resins. GB/T 2567-1995 General principles for performance test methods of resin castings GB/T2567-1995 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
General Test Methods for Properties of Resin Casting Body
1 Subject Content and Scope of Application
GB/T2567—1995
Replaces GB2567—81
This standard specifies the specimen preparation, specimen state adjustment and test standard environment for the performance test of resin casting body. This standard applies to castings of resin for fiber reinforced plastics and special casting resin. 2 Specimen preparation
2.1 Mould
2.1.1 Flat casting mould
2.1.1.1 Materials
The mould plate is a flat and smooth glass plate or steel plate, etc. Its size is determined by the required specimen area plus the mould frame area; a.
Mold release agent or mould release film can be made of release wax, cellophane, etc.; U-shaped mould frame, the metal wire is passed through the rubber hose to make a U-shape that matches the size of the mould plate; c.
Thickness control plug, determined by the thickness of the casting plate; d.
Bow clamp.
2.1.1.2 Mold making
Sandwich the U-shaped mold frame between two membrane plates that have been coated with release agent or covered with release film in advance. The opening of the U-shape is the casting port. The U-shaped mold frame is coated with release agent or covered with cellophane in advance. Use a bow clamp to clamp the template and the U-shaped mold frame. The spacing between the two templates is controlled by a plug.
2.1.2 Sample casting mold
2.1.3 Make the sample mold with steel or silicone rubber according to the standard sample size. The shrinkage rate of the resin should be considered in the design of the mold cavity size. 2.2 Batching and casting
2.2.1 Prepare according to the predetermined curing system and stir the components evenly. 2.2.2 Casting is carried out at room temperature of 15℃~30℃ and relative humidity less than 75%. Pour the glue liquid along the casting port close to the template. Try to avoid bubbles during the entire operation. If there are many bubbles, vacuum degassing or vibration degassing can be used. 2.3 Curing
2.3.1 Room temperature curing: After casting, the mold is placed at room temperature for 24 to 48 hours before demoulding. Then open it on a flat surface and place it at room temperature or standard ambient temperature for 504 hours (including sample processing time). 2.3.2 Room temperature heating curing: The casting mold is placed at room temperature for 24 hours before demoulding, and heating curing is continued, gradually rising from room temperature to the resin thermal deformation temperature, and the temperature is kept constant for several hours.
2.3.3 Heat curing: The curing temperature and time depend on the type of resin curing agent or catalyst. 2.4 Sample processing
2.4.1 Use a marking tool to mark the processing line on the casting plate according to the sample size. Sampling must avoid bubbles, cracks, pits, and stress concentration. Approved by the State Administration of Technical Supervision on December 20, 1995 and implemented on August 1, 1996
GB/T2567-1995www.bzxz.net
2.4.2 Use mechanical processing to process the sample. During processing, it is necessary to prevent the sample surface from being damaged and scratched. 2.4.3 The rough surface needs to be finely ground with a fine file or sandpaper, and the size of the notch is tested with a special sample. 2.4.4 Water cooling can be used during processing, and drying treatment should be carried out in time after processing. 2.5 Stress inspection
Before testing, the casting body is tested for internal stress with polarized light. If there is internal stress, it can be eliminated. 2.6 Methods for eliminating internal stress
2.6.1 Oil bath method
Place the sample stably in a container containing oil, and immerse the sample in the oil. Place the container with the sample immersed in the oil in an oven, and raise the temperature in the oven from room temperature to the resin glass transition temperature within 1 hour. After keeping the temperature constant for 3 hours, turn off the power supply. After the oven cools naturally to room temperature, take the sample out of the oil bath and observe the internal stress. Note: The oil used in the oil bath should not have a chemical effect on the sample, and should not swell, dissolve, or absorb. 2.6.2 Air bath method
Place the sample in a drying oven with a blast device, and the treatment temperature and time are the same as the oil bath. 3 Appearance inspection and quantity of samples
3.1 Before the test, the sample must be strictly inspected. The sample should be flat, smooth, free of bubbles, cracks, obvious impurities, processing damage and other defects. 3.2 Each group of valid samples shall not be less than 5.
4 Standard test environment conditions
Temperature (23±2)C, relative humidity (50±5)%. 5 Conditioning
Before the test, the sample should be placed under the standard test environment conditions for at least 24 hours (if there are special requirements, it can be determined as needed). 6 Sample measurement accuracy
The sample measurement size is not greater than 10mm, and the accuracy is 0.02mm, and the accuracy is 0.05mm for 10mm and above. 7 Test equipment
7.1 The load error of the test machine shall not exceed ±1%. The selection of the tonnage used should make the sample breaking load fall within the range of 10%~~90% of the full load (try to fall on the side of the full load) and not less than 4% of the maximum tonnage of the test machine (electronic tensile testing machine shall be implemented in accordance with relevant regulations). 7.2 The error of the deformation measuring instrument shall not exceed ±1%. 7.3 The testing machine shall be calibrated regularly by the national metrology department. 8 Test results
Provide the following data and curve charts as needed. 8.1 Test result of each specimen: αi, 2, .n. 8.2 Arithmetic mean X of each group of specimens, take three significant figures. 8.3 Standard deviation S of each group of specimens, take two significant figures. S
Where: ri-
Performance value of each specimen;
Number of specimens.
GB/T 2567-- 1995
8.4 Coefficient of dispersion C of each group of specimens, take two significant figures. C
Where the symbol is the same as in formula (1).
8.5 Load-deformation (deflection) curve
Read the load and corresponding deformation from the test machine dial and the deformation measuring instrument at appropriate intervals, and then draw a curve with load as the ordinate and deformation (deflection) as the abscissa. Electronic material testing machines can automatically draw a complete curve through a recorder or computer. Test report
The test report shall include the following items or parts of the contents:a.
Test item name;
Specimen source, variety, specification and preparation method;b.
Specimen number, size, appearance quality and quantity;c.
Test temperature, humidity and specimen state adjustment;e.
Test equipment and instruments;
Test results:
Give the performance value of each specimen (give the damage of each specimen if necessary), arithmetic mean, standard deviation, coefficient of dispersion, load-deformation (deflection) curve;
g. Test personnel, date and others.
Additional remarks:
This standard was proposed by the State Bureau of Building Materials Industry and is under the jurisdiction of the National Technical Committee for Standardization of Fiber Reinforced Plastics. This standard was drafted by Tianma Group Corporation.
The main drafters of this standard are Wang Yufen and Liang Liusheng. This standard was first issued in 1981.
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.