Premium
La caractérisation des amidons eu égard à leurs utilisations industrielles en particulier dans l'industrie textile et papetière
Author(s) -
Schutz Par R. A.
Publication year - 1971
Publication title -
starch ‐ stärke
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.62
H-Index - 82
eISSN - 1521-379X
pISSN - 0038-9056
DOI - 10.1002/star.19710231006
Subject(s) - starch , rheometer , rheology , materials science , shear rate , composite material , viscosity , mathematics , polymer chemistry , polymer science , pulp and paper industry , chemistry , food science , engineering
Characterization of Starches with Respect to their Application in the Industry, especially in the Textile and the Paper Industry. After a short review of the economical importance of starch in the textile and the paper sector the author shows how he characterizes the industrial starches: water content (after the French Standard AFNOR V. 03602), microscopic examination (normal and polarized light, phase contraste, 100 × or 250 × magnification), nitrogen content (Kjeldahl), ash content (AFNOR V. 03605), color, pH‐value of water extract, and particulary rheological behaviour. At this point the following is accentued: 1 Starch/water systems are not true Newtonian. They have not one viscosity alone but an infinity of apparent viscosities in relation with the rheological conditions. To give one value even in arbitrary units without precise informations about shear rate and shear stress is meaningless. 2 The preparation of the starch paste is a multiphenomene and needs a non‐laminar stirring. That means that it is illusive to obtain reproducible torque value by rotation at constant speed from one apparatus to another. 3 Only rheometers with coaxial cylinder permit an absolute characterization of the before prepared starch/water system.