Determination of softening temperature of powder coatings

In the Coatings industry, softening temperature is a key parameter. It describes the temperature at which powder coatings begin to melt, thus directly affecting the application and performance of coatings. This article will provide an in-depth look at softening temperature, how it is measured and why it is so important for powder coatings.

Definition of softening temperature

Softening temperature refers to the temperature at which powder coatings begin to melt. Different powder coatings will have different softening temperatures depending on their composition and manufacturing process. This temperature is an important indicator of Coating performance, as it can indicate in which temperature range the Coating is most stable and effective.

Determination of softening temperature

The determination of softening temperature has been described in detail in GB6554-2003 and the Kofler Hot Plate method is recommended. The following are the basic steps of this assay method:

Materials and Instruments

The Coffell Hot Plate is mainly used, which ensures the presence of a temperature layer from one end to the other during heating, usually from room temperature to 300 ℃. The Hot Plate is equipped with a temperature scale to indicate the temperature at each point, which can be corrected by using substances with known melting points such as azobenzene, naphthalene and benzoic acid.

Determination method

① sampling: According to the standard sampling method, only a small amount of powder sample is required.

Heat for more than 40 minutes until the Hot Plate temperature equilibrates. Select a known melting point substance close to the melting point of the material to be tested to check the temperature scale.

② Coat a small amount of the sample to be tested on the Hot Plate to form a thin and narrow powder strip. After about 1 minute, brush away the unmelted powder from the high temperature side to the low temperature side. Then adjust the pointer to the position where the melting starts, which is the softening temperature.

③ sexual repeability of the above steps three times, parallel measurement.

Result representation

The median of the three measurements is used as the final result, and the other two values are listed. The result unit is ℃.

The importance of softening temperature

Softening temperature is not only a criterion for evaluating powder coatings mass, but also directly affects the use and effect of Coatings. An excessively low softening temperature may mean that Coatings will melt and deform quickly in high temperature environments, while an excessively high softening temperature may make Coatings difficult to apply at room temperature.

In addition, by knowing the softening temperature of powder coatings, manufacturers can better select the right Application and market for their products, while helping users understand the temperature conditions at which the Coatings are most stable and effective.

Softening temperature is critical to the production and application of powder coatings. It not only serves as a criterion for evaluating product mass, but also provides manufacturers with valuable information to help them better position and market their products. The Coffell Hot Plate method provides us with an accurate and effective method for determining softening temperature, which ensures that we can accurately understand and control the performance and application of powder coatings.