This standard specifies the determination method of the color, appearance, mechanical or other property changes of plastics after exposure to natural or artificial light according to a specific exposure method. This standard is applicable to the investigation of the law and degree of color and property changes of plastics during aging tests in indirect sunlight under glass, natural climate or various artificial climate chambers with different light sources. It is also applicable to the evaluation of color fastness and property retention of plastics after exposure to other specific climatic conditions and specific time. GB/T 15596-1995 Determination of color and property changes of plastics after exposure to sunlight under glass, natural climate or artificial light GB/T15596-1995 Standard download decompression password: www.bzxz.net

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National Standard of the People's Republic of China
GB/T155961995
Plastics-Determination of changes in colour andvariations in properties after exposure to daylightunder glass,natural weathering or artificial light1995-06-12Issued
Implemented on 1995-12-01
Promulgated by the State Administration of Technical Supervision
National Standard of the People's Republic of China
Pinstieg-Determining changes in colour andvariations in properties after exposure to daylightunder glass,natural weathering or artificial light llgheCB/F15596—1995
This standard is equivalent to S015821930 Plastics—Determination of color and performance changes after exposure to sunlight under glass, natural climate or artificial light.
1 Main content and scope of application
This standard specifies the method for determining the color, appearance, mechanical or other performance changes of plastics after exposure to natural or artificial light according to the specified method.
This standard is generally applicable to the determination of the laws and processes of color and performance changes of plastics during aging tests under indirect sunlight under glass, natural air or various artificial climate chambers with different light sources. It is also applicable to the evaluation of color and performance retention rate of plastics after aging tests in other specific parts and for a specific period of time.
Note: Other resistance tests and other performance test standard methods may also be applicable (see 1 and Appendix A) 2 Cited standards
GB250 Grey scale for evaluating discoloration
GB1039
General principles for testing methods for mechanical properties of plastics
GB1010
Testing methods for tensile properties of plastics
GB1043www.bzxz.net
GB1843
Testing methods for impact of rigid materials
Testing methods for polymer impact of plastics
Testing methods for yellow finger plate of plastics
GR2 40S
GB2918
GB3681
GB3979
GB7921
GBS34E
GB9344
GB11997
Standard for the state adjustment and testing of plastic specimens. Test method for natural air exchange heating of plastics in difficult environments.
Method for measuring object color
Mean color space and color difference formula
Test method for the curvature performance of whole materials| |tt||Test method for plastic light source
Preparation and application of multi-purpose test material
GB13022
Test method for tensile properties of plastic film
GB/T14519 Test method for indirect exposure of whole material to sunlight after glazing
3 Determination of color or appearance change
3.1 Color change
C B/T15596-1955
Evaluate the color change of plastic specimens by visual inspection with contrasting color standards or by instrumental method. 3.1.2 Instrument
Gray scale for evaluating color change, in accordance with GB5U standard: In this scale, level 1 means large difference, level 5 is equivalent to a contrast of two scanned colors alternating),
b. Receiver for measuring color and shear color change (see GB2409GB3979 and GB7912). 3.1.3 The test sample for color change should be smooth, free of stains, scratches and other defects, uniform in color and thickness, and the required area should generally not be less than 3mm x 3mm, and should meet the national standard requirements for specific color change. 3.1.4 The test method should be evaluated by the method selected by the parties concerned or the instrument method. 3.1.4.1 The test method evaluation should be carried out in accordance with the principles and methods of GB250. The contrast between the test sample and the test sample should be compared with the color sample, and the color change degree of the sample should be expressed by the gray color scale with the same change and close contrast. If the contrast is between two color scale levels, it should be expressed by the middle level. For example, the contrast between the exposed sample and the control sample is greater than level 4 but less than level 3 of the gray scale.
When assessing the color change level, the type and nature of the color change should also be recorded, that is, any change in color, purity, brightness or any combination thereof. The following terms are attached to describe them.
Change in hue
Lightening
Change in purity
Change in brightness
This report will include yellowing, fading, brightening, graying, etc. The format of the sample 2~3 is as follows. 3.1.4.2 Instrumental evaluation
Instrumental evaluation should be carried out before and after the sample is exposed. If necessary, the exposed sample can also be compared with the control sample for evaluation. All samples shall comply with the relevant national standards. In addition to the method of measuring color value to indicate the degree of color change, the method of measuring yellow index is suitable for monochromatic, light-colored and colorless samples. If necessary, the change of transmittance at a specific wavelength or the change of selected incident light in the visible light region can also be measured for transparent or semi-transparent samples to help describe the time, degree and result of color change. 3.2 Other visible changes in appearance
In addition to the above provisions, any other visible changes in the sample can be selected for evaluation, such as: 2. Changes in the appearance of brightness and gloss: b. The occurrence of cracks, eye wrinkles, spots, porosity, loose state, delamination, warping, etc. c. The occurrence of easily removable substances and permeation products. 4 Determination of changes in mechanical properties
4.3
Under appropriate circumstances, the following samples shall be tested for mechanical or other properties (Appendix A lists other properties that can be selected). 2
GBT15596—1995
a. Samples before testing (initial properties)
Samples tested at a predetermined period:
Control samples protected from light for the same period of time (if necessary. The selection of performance items can be based on the national standards for the test materials, or can be agreed upon in advance by the parties concerned. The mechanical properties that should be used are tensile properties test (see GB1010 and GB13022, especially elongation at break and impact properties of notched or unnotched test pieces). Test (see GB1043), other performance tests (such as GB9341.GB1813, 4.2 The test fee
shall comply with the relevant national standards for the selected performance. 4.3 The test group
shall comply with the relevant national standards for specific exposure methods and performance test methods. 4.4 Determination of initial performance
Unless otherwise specified, the original sample shall be exposed to a standard environment and time specified in GB2918 for state conditioning. Special bad inspection is selected The parties concerned shall determine the properties selected according to the relevant national standards. If there is no suitable standard, the properties agreed upon by the parties concerned shall be determined (see 4.1). 4.4.2 Storage of control samples The control samples shall be stored under normal laboratory conditions, in the standard environment specified in GI291R, away from light. 4.4.3 Determination of properties at each stage The exposed samples and control samples (see 4.1) shall be kept under the same conditions as those used for the determination of the initial properties for state conditioning - post-combustion determination test For some tests, such as bending and impact tests, the measured data are related to the orientation of the test specimen when the test surface is tested. In this case, if there is no special requirement, it is recommended to turn the test surface to the back or front, so as to obtain the results of the energy change more quickly and shorten the test time.
5 Presentation of results
5.1 Color and appearance changes
Report color changes by visual inspection (see 3.1.4.1) or instrumental measurement (see 3.1.4.3). Report other appearance changes (see 3.1.4.4).2). The changes in appearance and surface properties should be expressed by the classification level agreed by both parties. The recommended classification levels are as follows.
--No ​​change:
Slight change
---Moderate change;
--Significant change,
5.2 Changes in mechanical and other properties
Determine the mechanical and other properties according to the relevant national standards and calculate the following averages: X; the average value of the initial performance value.
X, the average value of the performance of the sample at a certain stage. The average value of the performance value of the control sample after the corresponding exposure time in the dark. The numerical results of the exposed sample can be expressed by the retention rate of the initial performance value or the retention rate of the performance value of the sample after the exposure. Both methods are used. That is,
×100% or
(above)
G8/T15596-1995
For some performances, such as the change of drum volume or size, it is more convenient to express the results in the form of performance change rate. That is: ××100% or ×100%
For example, X. There is little difference with X. The result can be expressed by only the retention rate or change rate relative to the initial performance. If necessary, the performance change curve against time can be expressed, but special attention must be paid to the differentiation of the data to avoid the wrong conclusion caused by the drawn curve.
6 Test report
The test report shall include the following: 1
Indicate this standard;
Special description of the variety, specification and appearance of the test product; 1. Relevant information on the whole process (type, exposure stage, etc., if applicable, the relevant national standards should be stated); 2. Performance test methods, test equipment, test pieces and sample status; 3. Description of the test process (appropriate and relevant national standards): color change and appearance change at each stage, initial performance measurement values ​​and arithmetic mean values ​​of the test samples; various performance changes at each stage, and explanation of the expression method of the measurement results (excluding Chapter 5): test personnel, time and others.
GB/T15596
Appendix 4
Other flammability items for determining the performance changes of the sample before and after the mask
(Supplement)
In addition to the color, appearance and various performance items that can be measured in this standard, other performance test items that can be selected include: haze
surface resistivity
volume resistivity
breakdown voltage
dielectric loss angle
time-dependent change
mass change
softening temperature
heat deformation humidity
molecular size
melt flow rate
chemical change (such as cold base formation)
Additional remarks:
This standard is issued by the Ministry of Chemical Industry of the People's Republic of China and is under the jurisdiction of the National Technical Committee for Plastics Standardization, Aging Test Sub-Technical Committee. This standard was drafted by the Quality Research Institute of Chemical Industry.
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