Nylon processing, equipment

All of the above work was carried out with the same processing equipment and conditions. To explore the significance of different processing equipment in regard to mechanical performance, Dennis et al. [5] employed four different extruders to prepare nylon 6 montmorillonite nanocomposites. The nylon 6 for this study is the higher molecular weight version that was evaluated above. The two organomontmorillo-nites that were evaluated were Cloisite 30B and Cloisite 15A. 

Extmsion accounts for about 30% of nylon produced and is used in various processes (24). Nylons can be extmded on conventional equipment having the following characteristics. The extmder drive should be capable of continuous variation over a range of screw speeds. Nylon often requires a high torque at low screw speeds typical power requirements would be a 7.5-kW motor for a 30-mm machine or 25-kW for 60-mm. A nylon screw is necessary and should not be cooled. Recommended compression ratios ate between 3.5 1 and 4 1 for nylon-6,6 and nylon-6 between 3 1 and 3.5 1 for nylon-11 and nylon-12. The length-to-diameter ratio, T/D should be greater than 15 1 at least 20 1 is recommended for nylon-6,6, and 25 1 for nylon-12. 

Other, more recently developed, uses include microwave oven parts, transparent pipelines, chemical plant pumps and coffee machine hot water dispensers. One exceptional use has been to produce, by an extrusion moulding process, very large rollers for textile finishing for use where cast nylons cannot meet the specification. Also of growing interest are medical equipment applications that may be repeatedly steam-sterilised at 134°C, filtration membranes and cartridges for ink-jet printers. 

Processing and storage equipment for many chemicals, including acetaldehyde, formaldehyde, nylon salt, methyl methacrylate, carbon tetrachloride, glycerol, triacetin, proprionic acid, acetic acid and acetic anhydride, is manufactured from aluminium alloys, primarily because of their excellent corrosion resistance. 

The preparation of nylon in this way requires high temperature, special pressure and vacuum equipment, and a lengthy reaction period. The use of such processes is limited almost wholly to the preparation of polymers which are fusible and thermally stable. 

Equipment Is now commercially-available for nylon RIM and while process conditions are different from those required for urethane RIM, cycle times are competitive. No postcure is required. 

Nylon-based RIM systems differ from urethane RIM systems in several important aspects which impact the design of RIM equipment and the molding process conditions. 

The development of a Polyamide-6 (Nylon 6) production process as described in Sect. 1.2 is employed to illustrate the issues discussed in the previous subsection. Besides being a process of industrial relevance, it has certain properties which stress the importance of a neutral model integration platform. First, the behavior of polymer materials is more difficult to describe than that of ordinary fluids which are handled quite well by most state-of-the-art simulation packages. Further, non-standard pieces of equipment are used to realize the Polyamide-6 process in a technically and economically efficient manner. In addition, the complete process is supposed to be analyzed including the downstream extrusion of the material. This extrusion step is not only required to formulate the polymer product into a particulate material, but it also could... 

---