This standard specifies the test method for the compression creep of rigid foam plastic specimens under specified stress, temperature and relative humidity conditions. This standard is applicable to various rigid foam plastics. GB/T 15048-1994 Test method for compression creep of rigid foam plastics GB/T15048-1994 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Cellular plastics, rigid-Determination of compressive creep
GB/T 15048-94
This standard is equivalent to the international standard ISO7850-1986 "Rigid cellular plastics-Determination of compressive creep". 1 Subject content and scope of application
This standard specifies the method for determining the compressive creep of rigid cellular plastic specimens under specified stress, temperature and relative humidity conditions. This standard is applicable to various rigid cellular plastics. 2 Reference standards
GB2918 Standard environment for state adjustment and testing of plastic specimens GB6342 Determination of linear dimensions of cellular plastics and rubber 3 Principle
Under specified temperature and relative humidity conditions, the specimen is subjected to compressive deformation under constant pressure, and the change of compressive strain with time is measured. The initial deformation percentage and compressive creep percentage of the specimen are calculated. 4 Equipment
4.1 Test chamber
A constant temperature and humidity test chamber that can meet the requirements of 7.1 and 7.2. 4.2 Thickness measuring instrument
Should comply with the provisions of GB6342.
4.3 Loading device
The loading device consists of two parallel plates and a magnetic code. The two parallel plates should be able to compress the specimen vertically. One of the two plates is a movable plate with a guide device, and its lateral displacement should be less than 1mm. The two parallel plates should not deform during the test. The thickness of the specimen should be measured during the test with an accuracy of 0.1mm.
The loading device should remain horizontal and avoid vibration during the test. 5 Specimen
5.1 Shape and size
The specimen is a rectangular or cylindrical object with a force-bearing cross-sectional area of ​​at least 25cm. The standard specimen thickness is 50±1mm. The minimum specimen thickness is 20mm. When the thickness exceeds 50mm, its force-bearing cross-sectional area shall not be less than the square of the thickness. The thickness deviation between the two surfaces of the sample to be tested should not exceed 1% of the thickness. For products with skin in use, the sample should retain the product skin. The test results of materials with or without skin or different thicknesses are not comparable. 5.2 Preparation
The sample is cut from the sample, and the thickness direction of the sample should be consistent with the pressure direction of the product when it is finally used. Approved by the State Bureau of Technical Supervision on April 12, 1994 and implemented on December 1, 1994
GB/T15048-94
The sample can be cut with a saw, knife or other cutting tools, and ensure that the sample is not damaged. 5.3 Number of samples
Each group of samples shall not be less than three under the same test conditions. 6 Test steps
6.1 State adjustment
Carry out according to the standard environment and normal deviation range specified in GB2918, and the time shall not be less than 24h. 6.2 Method for creep test by applying pressure under standard environmental conditions (Method A) 6.2.1 After state adjustment, measure the thickness of the specimen to an accuracy of 0.1 mm. Measure at least four points for each specimen and calculate the average thickness H. 6.2.2 Place the specimen in the loading device, apply the selected pressure evenly and without shock, and measure the thickness H2 of the compressed specimen within 60 ± 10 s. Measure the thickness H3 of the specimen when the selected time is reached. 6.3 Method for creep test by applying pressure at selected temperature and relative humidity (Method B) 6.3.1 After state adjustment, measure the thickness of the specimen to an accuracy of 0.1 mm. Measure at least four points for each specimen and calculate the average thickness H1. 6.3.2 Place the unpressurized specimen and the loading device in a test chamber with selected temperature and relative humidity. After 24 hours, place the specimen in the loading device, apply the selected pressure evenly and without shock, and measure the thickness H2 of the compressed specimen within 60 ± 10 s. Measure the thickness H3 of the specimen when the selected time is reached.
7 Test conditions
7.1 Temperature
23,40,60,80,100,120,140±2C. 7.2 Relative humidity
5%,50%,90%±5% or constant humidity.
7.3 Pressure
10,20,30,40,50,100,150kPa±5%. 7.4 Time
1,2,7,14,28 days±5%.
The test conditions can also be carried out according to the requirements of the product standards. 8.1 Initial deformation percentage (D,), calculated according to formula (1): D
Where: Di-
H-H2× 100
Initial deformation percentage due to load, %, initial thickness of the unloaded specimen after state adjustment, mm; thickness of the specimen within 60±10s of pressure application under specified test conditions, mm. 8.2 Compression creep percentage (D.), calculated according to formula (2): Hz-Ha× 100
Where: De
Deformation percentage due to compression creep, %; thickness of the specimen at the selected time under specified test conditions, mm. H
8.3 The test results are expressed as the arithmetic mean of each group of specimens. 9 Test report
The test report shall include the following contents:bZxz.net
(1)
(2)
Name of this standard and standard number;
GB/T 15048-94
Sample name, type, batch number, production date, whether the sample has skin;
Sample thickness;
If the direction of pressure application is not parallel to the direction of use, its direction shall be indicated; the selected method (A or B), test temperature, relative degree, test pressure and load time; test results,
test date.
Additional remarks:
This standard was proposed by the China Light Industry General Association.
This standard is under the jurisdiction of the National Technical Committee for Standardization of Plastic Products. This standard was drafted by the Plastic Processing and Applied Science Research Institute of the Ministry of Light Industry. The main drafters of this standard are Zeng Xinrong, Yang Lin and Chen Qian. 473
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.