Plastics fluidity

Scott-Blair, G. W. 1953. Foodstuffs Their Plasticity, Fluidity and Consistency. North-Holland Publishing Co., Amsterdam. 

Fliess-barkeit,/. flowing quality, fluidity fusibility. -bereich, m. plastic range, -betrieb, m. — Fliessarbeit. -druck, m. flow pressure hydraulic pressure, -eigenschaf /. rheologic property. 

By permission from Fluidity and Plasticity, by E.C. Bingham. Copyright 1922. McGraw-Hill Book Company Inc.)... 

R. Abegg, A. Kanitz, and 0. Pulvermacher have measured the viscosity of soln. of ammonium nitrate, and H. Gorke the reciprocal of the viscosity, i.e. the fluidity at different temp, (water at 25° unity), and his measurements are indicated in Table LXI. A. Kanitz also measured the viscosities of mixtures of ammonium nitrate with potassium, sodinm, or barium nitrate, and found that the results follow the additive rule very closely. W. N. Bond studied the plasticity of crystals of ammonium nitrate. 

Bingham, E. C., Fluidity and Plasticity, 1922. New York McGraw-Hill. 

Compatibility of PVC with plasticizer (PI) also strongly influences the rheological and processing properties of plastisols 48>. The effects of the diverse plasticizers on PVC varies since some plasticizers (even well compatible with polymer), e.g. dibutylphthalate (DBP), may readily escape from the obtained materials and articles 17,23,43. Plasticizers which are poorly compatible with PVC (the so-called secondary PI ) may be used for the purpose-oriented change of viscosity properties of a system (fluidity increase) and saving the base PI component. 

Plastic properties are sensitive to the oxidation or weathering of coals. Maximum fluidity is lessened, and extensive oxidation may destroy the fluidity of coal completely. Samples should be tested as soon as possible after they are collected and should be stored under water or in a nonoxidizing atmosphere if there is to be a delay before they are tested. Proper packing around the stirrer in the plastometer is an important step in the measurement of plastic properties. Some coals may not pack easily due to their weathered condition or to the size consist of the sample. An excess of very fine coal makes the test sample hard to pack. 

When coal is heated in a vacuum, the plastic range is generally reduced substantially, perhaps because of the rapid evaporation of the bituminous hydrocarbons that are reputedly responsible for the fluidity of the plastic coal. Heating coal to the plastic range followed by rapid cooling yields coal with a lower softening point (if plasticized a second time), and this has been ascribed to the presence of liquid in the coal that arose from the first heating. 

The results from a test may also be used as an indication of the caking characteristics of the coal when it is burned as a fuel. The volume increase can be associated with the plastic properties of coal coals that do not exhibit plastic properties when heated do not show free swelling. It is believed that gas formed by thermal decomposition while the coal is in a plastic or semifluid condition is responsible for the swelling. The amount of swelling depends on the fluidity of the plastic coal, the thickness of bubble walls formed by the gas, and interfacial tension between the fluid and solid particles in the coal. When these factors cause more gas to be trapped, greater swelling of the coal occurs. 

Fluidity degree of plasticity exhibited by a sample of coal heated in the absence of air under controlled conditions (ASTM D-1812 ASTM D-2639). 

The last term takes account of slippage at the boundaries. Buckingham assumes that there is a very thin lubricating layer (of thickness 8 and fluidity m") between the plastic material an4 the wall. Examination of Buckingham s equation indicates that flow at pressures less than h increases directly as the pressure. At pressure ho shearing begins and the relation is shown by a curved line AB in Figure 91. 

Fluidity and plasticity. New York McGraw-Hill Book Co., 1st ed. 

Because of its cylindrical shape and hydrophobic character, cholesterol is an important component of the membranes of animal cells. Its rigid structure decreases membrane fluidity, but it also inhibits the crystallization of fatty acid side chains of the membrane lipids and it acts as a sort of membrane plasticizer. 

For the definition of the terms yield value and flow see also Bingham, Fluidity and Plasticity. This abstract of Bartell and Hershberger s paper differs from that given by the authors, but it seems to be justified on a careful analysis of the data recorded. 

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