MFR
Laboratory > Physicals
Melt flow index (MFI) | |
Melt flow index is the most popular method in the plastics industry to determine the viscosity of the material and is often used to test consistency from batch to batch. However, it is also the least accurate method. To obtain more significant data, a capillary rheometer or cone and plate rheometer should be used to determine the viscosity. Some companies will also perform rheology tests on the mold using real manufacturing molds. The melt flow index (MFI) or the melt flow index (MFR) is a measure of the ease of flow of molten plastics. It is often used in the plastics industry for the quality control of thermoplastics. The method is described in the ASTM D1238 and ISO 1133 standards. A small sample of 5 ÷ 10 grams above its melting or softening point is heated and forced to flow through a capillary using a piston driven by a weight specific depending on the type of polymer, generally 2.16 kg, 5 kg and 21 kg. The weight of the melt in grams that flows through the capillary in 10 minutes is the melt flow index. |