Polymer Processing

Chapter 3. Polymer Processing Polymer Process Techniques Fig. 3. 1. Procedure for casting sheets of polymer. Polymer Materials Page ? 2 Polymer Process Techniques HEMA = hydroxyethyl methacrylate EGDMA = ethylene glycol dimethacrylate Fig. 3. 2. Centrifugal mold for poly(hydroxyethyl methacrylate) contact lenses Solvent casting of films Fig. 3. 3. Laboratory spreading device for the solution casting of films. Polymer Materials Page ? 3 Polymer Process Techniques Roll casting Fig. 3. 4. Knife coating of a polymer onto a film. Polymer Materials Page ? 4 Polymer Process TechniquesFig. 3. 5. Polymer casting bench. Polymer Materials Page ? 5 Polymer Process Techniques Fig. 3. 6. Solution casting of films on an industrial scale with the use of rotating metal drums. Polymer Materials Page ? 6 Polymer Process Techniques Fig. 3. 7. Use of a moving-belt system for the continuous solution casting of polymer films. Polymer Materials Page ? 7 Polymer Process Techniques Fig. 3. 8. ‘Bubbleâ⠂¬â„¢ blowing of films. Polymer Materials Page ? 8 Polymer Process Techniques Fig. 3. 9. Film manufacture by calendering. Polymer Materials Page ? 9 Polymer Process TechniquesMethods for melt processing of films Fig. 3. 10. Hydraulic press for the melt pressing of polymer films. Polymer Materials Page ? 10 Polymer Process Techniques Fig. 3. 11. Sequence of operations for the melt extrusion of polymer films. Polymer Materials Page ? 11 Polymer Process Techniques Fig. 3. 12. Diagram of a plastics extruder. Polymer Materials Page ? 12 Polymer Process Techniques Fig. 3. 13. Diagram of a compression-molding press and mold. Polymer Materials Page ? 13 Polymer Process Techniques Melt process Fig. 3. 14. Diagram of an injection-molding machine. Polymer MaterialsPage ? 14 Polymer Process Techniques Fig. 3. 15. Thermoforming of polymer sheets. Polymer Materials Page ? 15 Polymer Process Techniques Fig. 3. 16. ‘Plug flow reactor’ to manufacture radiation crosslinked tubings or bel ts. Polymer Materials Page ? 16 Polymer Process Techniques Reaction Injection Molding (RIM) Advantages: ? Large parts ? Low viscosity ? Inexpensive Materials : ? Urethanes ? Polyureas ? Nylon ? Polyolefins Fig. 3. 17. Reaction injection molding (RIM) device to produce reinforced polyurethanes. ? Cylinder charged with diol and triol plus dibutyltin dilaurate ?Cylinder charged with molten diisocyanate ? Half of split mold ? Half of split mold ? Cavity to be filled with reinforcing fiber, then with mixed liquid from nozzle ? Nozzle for mixing streams from ? and ? Polymer Materials Page ? 17 Polymer Process Techniques Fig. 3. 18. Apparatus for the laboratory wet spinning of fibers. Polymer Materials Page ? 18 Polymer Process Techniques Fig. 3. 19. Use of a motor-driven syringe pump for the laboratory preparation of wet-spun fibers. Polymer Materials Page ? 19 Polymer Process Techniques Fig. 3. 20. Laboratory assembly for the ry spinning of fibers. Polymer Materials Page ? 20 Polymer Pro cess Techniques Fig. 3. 21. Industrial wet spinning. Polymer Materials Page ? 21 Polymer Process Techniques Fig. 3. 22. Laboratory or pilot-plant equipment for the melt extrusion of fibers. Polymer Materials Page ? 22 Polymer Process Techniques Fig. 3. 23. Manufacturing equipment for the dry spinning of fibers. Polymer Materials Page ? 23 Polymer Process Techniques Fig. 3. 24. Equipment for the melt spinning of fibers on an industrial scale. Polymer Materials Page ? 24 Polymer Process Techniques Fig. 3. 25.Three methods for the continuous orientation of synthetic fibers. (a) The fiber passes round a ‘peg’ which stabilizes the stretch orientation being induced by the faster-turning set of rollers. (b) The faster-turning drum stretches the polymer in the orientation zone. With this technique some difficulty may be experienced with stabilization of this zone. (c) The two drums turn at the same speed. But the fiber is stretched because of the greater circumference of the se cond drum. Polymer Materials Page ? 25 Polymer Process Techniques Processing of Elastomers (Vulcanizable) Fig. 3. 26.Reactor to manufacture four-ply valcanized rubber belts. Polymer Materials Page ? 26 Polymer Process Techniques Fig. 3. 27. Tire molding process Polymer Materials Page ? 27 Polymer Process Techniques Composite & Laminate Processing Fig. 3. 28. Plug-flow reactor to form epoxy resin preimpregnated sheet. Polymer Materials Page ? 28 Polymer Process Techniques Fig. 3. 29. ‘Batch reactor’ to manufacture glass-fiber reinforced polyesters. Polymer Materials Page ? 29 Polymer Process Techniques Fig. 3. 30. Procedure used to manufacture fiber reinforced epoxy resins. Polymer Materials Page ? 30