GB428174A - Method of and apparatus for testing materials having plastic or fermentative properties - Google Patents

Abstract

428,174. Testing dough &c. CHOPIN, M. J. E., 133, Boulevard Exelmans, Paris. July 25, 1934, No. 21787. Convention date, Dec. 11, 1933. [Class 58] [See also Group XIX] To measure the plasticity of a material such as dough, a test piece of spherical form is placed on an horizontal plate so that the test piece flattens gradually solely by reason of its own weight and the dimensions assumed by this test piece are measured after a definite time of flow. In the form of apparatus shown a test piece of material formed of definite quantities of constituents heated to the temperature selected for the test is given a spherical form by placing it in a former, Fig. 2, comprising two hollow hemispherical bodies 3, 3<1>, connected by a cylindrical tube 4 and powdered or roughened internally to prevent adhesion, the former being subjected to successive inversions ; an iris diaphragm 5 let into a casing 6 is closed when the sphere is formed so that the sphere of material may rest thereon while the lower part of the casing is removed, subsequent gradual opening of the diaphragm permitting the sphere to pass through and be deposited on the test disc 2<1>, Fig. 3. The disc 2<1>, provided with a centring cone frustum 10, rests on an upstanding portion 9 of a metal stand 7 formed with a recess containing water 8. The stand is provided with a water circulation conduit 13, a heating resistance 14 and a temperature regulator ; the test material is covered by a thermally insulated casing fitted with a clear glass window 17 and a ground glass window 18. The dimensions of the test piece are observed by taking the dimensions of its shadow cast on the ground glass by a point source of light 21 provided with adjusting screws. A hand wheel 12 provides means for rotating the test piece and screws 24 for levelling the stand. The dimension of the test piece may be obtained photographically, a clockwork device moving a sensitized paper or film into position, this device also rotating the disc, or by electrodes brought into contact with the test piece the electrodes being connected by flexible wires to styles that record the position on a recording cylinder ; a cathetometer may also be used.