Processing, thermoplastics jetting

In case of an accurate formulation of the problem, it is difficult to consider theoretically the process of molten thermoplastic drawing from a molding tool even under isothermic conditions. In the literature several approximate approaches have been suggested. For instance, it has been proposed 83 84), for analysis of a similar problem (isothermic swelling of a jet leaving the capillary without subsequent drawing), to cross-link the inner (in the capillary) and the outer (free jet outside the capillary)... 

We now consider the interface between carrier and toner, as these components interact in a dynamic development system. As we have noted, toner is commonly fabricated by "jet impacting" a brittle pigmented thermoplastic to form irregularly shaped particles of about 12/u m cross-section--particles whose surface comprises resin and carbon black (2, J 3, 58). The carrier cores are magnetic (ferrite or steel), typically about 250/4 m in size and therefore relatively massive. They are generally coated with a dielectric oxide or resin, which participates in the tribo-electrification process (2, it , 59). ... 

Polyetherlmldes Thermoplastic cyclized polymers of aromatic diether dianhydrides and aromatic diamine. Has good chemical, creep, and heat resistance, and dielectric properties. Processed by extrusion, thermo forming, and compression, injection, and blowmolding. Used in auto parts, jet engines, surgical instruments, industrial apparatus, food packaging, cookware, and computer disks. Also called PEI. 

Polyferrocenylsilanes can be fabricated into films, shapes, and fibers using conventional polymer processing techniques. The dimethyl derivative 3.22 (R=R = Me), which has been studied in the most detail, is an amber, film-forming thermoplastic (Fig. 3.7a) which shows a Tg at 33°C and melt transitions (T ) in the range 122-145 °C. The multiple melt transitions arise from the presence of crystallites of different size, which melt at slightly different temperatures [65, 100). Poly(ferrocenyldimethylsilane) 3.22 (R=R =Me) can be melt-processed above 150°C (Fig. 3.7b) and can be used to prepare crystalline, nanoscale fibers (diameter 100 nm to 1 pm) by electrospinning. In this method, an electric potential is used to produce an ejected jet from a solution of the polymer in THF, which subsequently stretches, splays, and dries. The nanofihers of different thickness show different colors due to interference effects simUar to those seen in soap bubbles... 

Carbon fiber reinforced PEI thermoplastic floor panels have been developed for the Gulfstream V corporate jet, replacing a heavier A1 design [167]. The floor panels eomprised preconsolidated carbon fiber/PEI skins bonded to each side of a Nomex/phenolie honeyeomb and processed by thermoforming and ultrasonic welding. 

Petrochemicals Platinum is a key catalyst in the processing of low-lead and unleaded gasoline and jet fuel, in petroleum refining, and in catalytic reforming. Petrochemical uses of platinum also include the manufacture of thermoplastics and polyester. 

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