Extrusion scale

Reactions 14-39 and 17-20 also fit this definition. Reaction 17-29 does not fit the definition, but is often also classified as an extrusion reaction. An extrusibility scale... 

Reactions 14-32 and 17-20 also fit this definition. Reaction 17-28 does not fit the dehnition, but is often also classified as an extmsion reaction. An extrusibility scale has been developed, showing that the ease of extrusion of the common Y groups is in the order -N=N- > -COO- > -SO2- > -CO-. ... 

Polyethylene can be compounded on any of the standard types of mixing equipment used for visco-elastic materials. For laboratory purposes a two-roll mill is suitable operating temperatures varying from about 90°C to about 140°C according to the type of polymer. On the industrial scale, compounding is undertaken either in internal mixers, or more particularly, extrusion compounders. 

A laminar-flow reactor (LFR) is rarely used for kinetic studies, since it involves a flow pattern that is relatively difficult to attain experimentally. However, the model based on laminar flow, a type of tubular flow, may be useful in certain situations, both in the laboratory and on a large scale, in which flow approaches this extreme (at low Re). Such a situation would involve low fluid flow rate, small tube size, and high fluid viscosity, either separately or in combination, as, for example, in the extrusion of high-molecular-weight polymers. Nevertheless, we consider the general features of an LFR at this stage for comparison with features of the other models introduced above. We defer more detailed discussion, including applications of the material balance, to Chapter 16. 

PS and PMA extrusion products (5 minutes) is good up to about 280°C. P.R.31 is stable to the usual peroxide catalysts. The pigment is lightfast (0.025% formulations in PMA, 1.5 mm thickness of layer step 7 on the Blue Scale). P.R.31 is also used in textile printing. 

Processability Extrusion rate, pilot scale, U.S. Patent 5 683 973 [8]... 

Numerous carriers were produced from different recipes and in different sizes and shapes in a 1 kg/min lab scale extruder and subsequently calcinated under different conditions in a furnace. The recipes included different types of diatomaceous earth, different types and amounts of binder and variation of the water content of the paste, which is a critical extrusion parameter. The shapes included among others rings, multiple-holed rings, finned rings, and trilobes, whereas normal cylindrical pellets were not made due to their well-known inferior activity to pressure drop ratio. 

Fiber orientation uniformity is also affected by small-scale or timewise variations in polymer viscosity, related to breakage of polymer chains during the extrusion process. The degradation occurs as a result of residual moisture that immediately reacts to break chains, and by thermal degradation that occurs more gradually over time. Different residence times and temperature histories within the laminar flow streamlines lead to different viscosities, and hence different average orientation levels in the different fibers. 

The remaining Chapters 9 through 15 are devoted to different types of extrusion troubleshooting analyses. These chapters include presentations on scale-up tech-... 

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