![]() And the screw can be water cooled to further prevent polymer from sticking to it. But there are no common polymers that melt below 200° F, so there is plenty of temperature range to work with without causing trouble. That seems to be the main fear operators have about running a hotter feed throat. There are, of course, limits on how high the feed-throat temperature can be raised without causing some melting to occur, particularly when screw rotation is stopped. Over-cooling the feed throat also hurts the output and compaction, which does not occur entirely in the limited length of the feed throat. The “drain” of heat from zone 1 by the feed throat can be considerable if the feed throat is over-cooled, so cutting back the cooling-water flow is usually the best starting point. On most extruders the feed throat is not heated, so its temperature must be controlled by heat conducted from zone 1 of the barrel and by regulation of the cooling water. That drag difference is generally achievable by raising the temperature of the feed throat. All polymer bulk densities are 20-40% of the solid density, so improved compaction is a principal benefit of optimized feeding. Different bulk densities are another important variable. Even different pellet shapes and particle-size distributions of the same polymer require different feed-throat temperatures. Different feed-throat geometries, polymer properties and thermal heat transfer require different temperatures for optimum processing. Obviously, nothing comes out the die that doesn’t go in through the feed throat. Melt temperature and melt uniformity for a given screw design are affected by the feed rate, as it affects the degree of fill in the rest of the screw. It integrates with every aspect of the streaming experience, providing animated video overlays for rendering show graphics, a web-based control panel for switching cameras and managing other show elements, and integration with Twitch's. Feeding not only controls the extruder output but also influences process stability and even the melt condition. Sous Chef is a comprehensive companion app for hosting cooking shows on the Twitch livestreaming platform. It can be an important operating parameter. ![]() One aspect of single-screw extrusion you don’t hear much about is feeding. Feed-throat temperature is not discussed much, but makes a big difference in extrusion output, stability and melt quality.
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