试验环境对塑料拉伸检测的影响
Influence of test environment on plastic tensile testing
影响塑料拉伸试验数据的因素有许多：如振动、温度、湿度、人员等，其中最主要的因素是温度和湿度。GB/T8804中规定，实验室环境温度为（23±2）℃，相对湿度为（50±10）%。
There are many factors that affect the data of plastic tensile test, such as vibration, temperature, humidity, personnel, etc., the most important of which is temperature and humidity. According to GB / t8804, the laboratory environment temperature is (23 ± 2) ℃, and the relative humidity is (50 ± 10)%.
热塑性塑料的拉伸性能测试受温度的影响比较大，往往温度偏高，拉伸强度偏低，伸长率偏大，反之则相反。伴随着温度的逐渐上升，热塑性塑料的拉伸性能也将逐渐由硬脆向粘强转变，拉伸强度和拉伸弹性模量随之变小，而断裂伸长率将同步变大。
The influence of temperature on the test of the tensile properties of thermoplastics is relatively large. The temperature is often high, the tensile strength is low, and the elongation is too large. On the contrary, it is the opposite. With the gradual rise of temperature, the tensile properties of thermoplastic will gradually change from hard brittleness to viscosity strength, and the tensile strength and elastic modulus will be smaller, while the elongation at break will be larger at the same time.
实验相对湿度一般对吸水率比较大的塑料影响较大。一部分塑料吸水率增大以后，水分子在塑料中起到了偶联剂和增韧剂的作用，从而影响该塑料的刚性和韧性。通过以上实践可见，塑料的拉伸性能测试必须在恒温恒湿条件下进行。
In general, the experimental relative humidity has great influence on the plastics with high water absorption. After the water absorption of some plastics increases, water molecules play the role of coupling agent and toughening agent in the plastics, thus affecting the rigidity and toughness of the plastics. It can be seen from the above practice that the tensile properties of plastics must be tested under constant temperature and humidity.