Filaments extrusion

Part Design Blow Molding Casting Compression Extrusion Filament Winding Injection Matched Die Molding Rotational Thermo- forming Transfer Compression Wet lay-up (Contact Molding)... 

Part design Blow molding Casting Compression Extrusion Filament winding Injection Matched die molding Rotational Thermo- forming Transfer compression Wet lay-up (contact molding)... 

FIGURE 11.3 Dry extrusion filaments emerging from spinner. (From G.M. Moelter and R. Steele, In J. McKetta, ed., Encyclopedia of Chemical Processing and Design, vol. 1, Marcel Dekker, New York, 1976, p. 171.)... 

The rapid extraction of the solvent prevents proper filament formation and makes the filament crumbly. That is why good results may be obtained by methylene chloride extraction after solidification with water. A wet spinning process with solvent extraction and stretching consists of [43] extrusion, filament solidification, first solvent extraction, first water stretching, second solvent extraction, second hot air stretching, takeup. 

Extrusion Processes. Polymer solutions are converted into fibers by extmsion. The dry-extmsion process, also called dry spinning, is primarily used for acetate and triacetate. In this operation, a solution of polymer in a volatile solvent is forced through a number of parallel orifices (spinneret) into a cabinet of warm air the fibers are formed by evaporation of the solvent. In wet extmsion, a polymer solution is forced through a spinneret into a Hquid that coagulates the filaments and removes the solvent. In melt extmsion, molten polymer is forced through a multihole die (pack) into air, which cools the strands into filaments. 

Extrusion Resins. Extmsion of VDC—VC copolymers is the main fabrication technique for filaments, films, rods, and tubing or pipe, and involves the same concerns for thermal degradation, streamlined flow, and noncatalytic materials of constmction as described for injection-molding resins (84,122). The plastic leaves the extmsion die in a completely amorphous condition and is maintained in this state by quenching in a water bath to about 10°C, thereby inhibiting recrystallization. In this state, the plastic is soft, weak, and pHable. If it is allowed to remain at room temperature, it hardens gradually and recrystallizes partially at a slow rate with a random crystal arrangement. Heat treatment can be used to recrystallize at controlled rates. 

Deformation of a solution usually either by spreading or by extrusion as used in making cast film and certain synthetic fibres and filaments. 

Filament is prepared by extrusion followed by hot stretching. It may be used for brush bristles or for decorative purposes such as in the manufacture of woven lampshades. 

Material Family Injection Compression Hansfer Casting Cold Molding Coating Structural Foam Extrusion Laminating Sheet Forming RP Molding FRP Filament Dip and Slush Blow Rotational... 

Extrusion texturization is a process that uses mechanical shear, heat, and pressure generated in the food extruder to change the structures of food components, including proteins (Harper, 1986). Protein texturization creates filamentous structures, crumbly surfaces, or other physical formations by restructuring or realigning folded or tightly wound globular structures into stretched, layered, or cross-linked mass (Kinsella and Franzen, 1978). 

In addition to the conventional dyeing of acrylic fibres, there is considerable interest in so-called gel dyeing of acrylic filaments during the manufacturing process after extrusion. From the viewpoint of auxiliary usage this is outside the scope of the present work, but a useful account of the factors involved is available [61]. 

Spinnerets, for olefin fiber extrusion, 22 627, 630-631, 11 231-232 Spinner flasks, 15 691-692 Spinning. See also Solution spinning Yarn spinning technologies air gap, 11 209 of continuous-filament yarns,... 

After the polymer is formed, the filament is produced by extrusion. The nylon can be taken directly from the polymerization process while it is still molten. Alternatively, previously dried nylon chips can be heated and melted. The molten nylon is pressed through a spinneret, which is like a showerhead with 10—100 holes. (A spinneret with a single hole produces a monofilament. Nylon monofilaments are used for fishing line and sheer... 

The stretching of the dye for operation in extrusion mode is shown in Fig. 8.3. As shown in Fig 8.3(a), the dyed drop stretched in a nearly constant and helical trajectory down the extruder. Closer to the exit the drop continued to be stretched as indicated by the smaller cross section of the tinted fluid filament, as shown in Fig. 8.3(b). The typical mixing in this mode of operation results in a dye monofilament that remains contiguous. Although not shown here, the trajectory and stretching depends on the starting position of the dye drop. 

Fibers can be formed from intractable materials such as ceramics and polytetrafluoro-ethylene through extrusion of a suspension of fine particles in a solution of a matrix polymer. The matrix polymer-intractable material is coagulated embedding, aligning the intractable material in the matrix polymer. The filament is then heated decomposing the matrix polymer. During this process, the material is sintered and drawn giving small, often with little flexibility—fibrils. 

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