The Density / Specific Gravity Test is a standard method used to determine the density and relative density of plastic materials. Based on Archimedes' Principle, the test measures the specimen's weight in air and in water to calculate its density and specific gravity. It is widely used in quality control, material identification, product development, and research to verify polymer grades and ensure compliance with material specifications.

The Heat Deflection Temperature (HDT) and Vicat Softening Temperature (VST) tests are important thermal tests used to evaluate the heat resistance of thermoplastic materials. HDT determines the temperature at which a plastic specimen bends under a specified load, indicating its ability to retain shape under mechanical stress at elevated temperatures. VST determines the temperature at which a standard indenter penetrates 1 mm into the softened material, indicating the material's softening point. These tests are widely used in quality control, material selection, product development, automotive, electrical, packaging, and engineering industries to ensure plastics perform reliably at elevated temperatures.

The Melt Flow Index (MFI) Test, also called the Melt Flow Rate (MFR) Test, is a standard method used to determine the flow characteristics of molten thermoplastic materials. The test measures the mass of polymer extruded through a standard die in 10 minutes under controlled temperature and load conditions. MFI is widely used in the plastics industry for quality control, material selection, process optimization, and product development, as it provides a quick indication of a polymer's processability and viscosity.