GB/T 37426-2019 Plastics—Test specimens
GB/T 37426-2019 Plastics—Test specimens
Basic Information
Scope
This standard specifies the size requirements for samples prepared from plastic materials by molding or machining from sheets or profiles. This standard also provides sample naming and size specifications for obtaining comparable data, as well as naming and size specifications for other commonly used samples.
This standard specifies the following sample types, each of which may contain samples of different shapes and sizes:
a) Type A samples
Tensile samples, obtained by simple molding methods, which can be cut for use in other tests (see Appendix A), including Type A1 and Type A2 samples (1= injection molding, 2= machined from sheets or profiles).
Type A1 samples are multi-purpose samples. The main advantage of multi-purpose samples is that all laboratories can complete all the tests mentioned in Appendix A using multi-purpose samples obtained from comparable molded pieces. Therefore, the performance data measured on the same samples prepared using the same method are consistent. In other words, it can be expected that the test results of a group of samples will not change significantly due to unintended changes in molding conditions. On the other hand, it is easy to evaluate the impact of molding conditions and/or different states of the samples on the test performance if necessary.
The scaled samples are named Type Axy, where x is the method of sample preparation (1= injection molding, 2= machined from sheets or profiles) and y is the scale reduction factor (1:y). Scaled samples can be used in situations such as when full-size samples are not convenient to use or when the quantity of material is small.
b) Type B samples
Strip-shaped samples, which can be directly molded or obtained from the middle part of Type A1 samples or machined from sheets or profiles.
c) Type C samples
Small tensile samples, which can be directly molded or obtained from sheet-shaped samples (such as Type D or Type F samples) machined from