RHEOMETERS FOR POLYMER MELT CHARACTERIZATION

A rheometer is an instrument for measuring the rheological properties and can do one of the following two things  

It can apply a deformation mode to the material and measure the subsequent force generated. 

It can apply a force mode to a material and measme the subsequent deformation. 

The best designs of rheometers use geometries so that the forces/deformation can be reduced by subsequent calculation to stresses and strains, and so produce material parameters. 

Rheometers used for determining the material functions of thermoplastic melts can be divided into two broad categories (1) rotational type and (2) capillary type. Further, subdivisions are possible and these are shown in Table 3.2. In what follows, only those rheometers which are popularly used for rheological 

Rheometry is the measuring arm of rheology and its basic function is to quantify the rheological material parameters of practical importance. Rheometry is normally used in the thermoplastics industry to provide rheological information for dii erent purposes at various levels of sophistication, as can be seen from Table 3.1. Althou it is often essential to have the complete Geological characterization of the thermoplastic in use, different sections of the industry do resort to shortcuts based on limited rheological information generated by simple unsophisticated rheometers due to lack of time, finances, and technical personnel. 

---