Jiangmen engineering plastics has been widely used in our daily life mainly as engineering materials and substitute for metal manufacturing machine parts. In the car industry, the car has been lightweight, safe and environmentally friendly by replacing steel with plastic.

In the material selection of engineering plastics, the data engineer must consider not only the mechanical function, aging resistance function and the strength of engineering plastics manufacturers, but also its thermal function. How many thermal functions of engineering plastics have been tested?

1. Continuous operating temperature

Indicate the heat resistance of plastic molded products. Generally, it is divided into physical heat resistance and chemical heat resistance. The former refers to the function of regular shaped plastic molding style to adhere to the product shape under the specified heating temperature; The latter indicates the thermal stability of the bisector bond of the plastic molding material.

The first is to indicate the heat-resistant function of plastic molding style under no-load conditions. The long-time working temperature of common engineering plastics such as PEEK is 260 ℃.

2. Glass transition temperature

When the temperature is higher than TG, the amorphous polymer will become soft and rubbery. It is very important to ensure that the operating temperature of the amorphous polymer is lower than TG, so as to achieve the desired mechanical function.

3. Thermal deformation temperature

Thermal deformation temperature is a simple expression of load deflection temperature. It is a method to measure the rigidity of plastics at high temperature: under a certain load, keep heating at a certain speed until the style shows the temperature when the deformation is indicated.

Since the load deflection temperature is the lower limit temperature indicating that it is close to the glass transition temperature in amorphous plasticity, it can become a practical reference policy.

However, in the case of crystalline plasticity, the load deflection temperature is the temperature between the glass transition modification point and the crystallization melting point, so it is meaningless both in theory and in practice, and the error of the measurement effect is also very obvious. This parameter is used to measure the temperature tolerance of different data under short-time temperature rise and load.

4. Linear expansion coefficient

Linear expansion coefficient refers to the expansion share of plastic molded products when the temperature rises by 1 ℃ under a certain pressure. It is indicated as the linear expansion coefficient relative to the unit length. This coefficient is one of the important policies to understand the degree of product standard change with the temperature rise of plastic formed products.

5. Thermal conductivity

The thermal conductivity indicates the heat of plastic products with a temperature difference of 1 ℃ and a thickness of 1 cm within 1 s. It is a reference policy for discussing the thermal insulation of policy products when planning products.

6. Specific heat capacity

Specific heat capacity refers to the heat capacity relative to the unit mass (1g) of plastic molded products. Generally, it indicates the heat required when the temperature of plastic molded products rises by 1 ℃. The specific heat capacity is the same as the thermal conductivity, which is the reference data for discussing the temperature rise of policy products during product planning.

7. Embrittlement temperature

A measure of the low temperature mechanical behavior of plastics. When the specimen is impacted by a hammer with certain energy, the temperature when the cracking probability of the specimen reaches 50% is called the embrittlement temperature. Determination of embrittlement temperature: clamp one end of the regular shape and standard molding style with the test pliers, fix it in the test tank, soak it in the specified low-temperature heat transfer foreword at all levels, place it for 2.9-3.1min, and knock it once with the impact hammer to calculate the embrittlement temperature from the effect of the damaged style.

Source: Jiangmen engineering plastics http://m.feimandao.com/