Molded nylon

Red Phosphorus. This aHotropic form of phosphoms is relatively nontoxic and, unlike white phosphoms, is not spontaneously flammable. Red phosphoms is, however, easily ignited. It is a polymeric form of phosphoms having thermal stabiUty up to ca 450°C. In finely divided form it has been found to be a powerful flame-retardant additive (26,45—47). In Europe, it has found commercial use ia molded nylon electrical parts ia a coated and stabilized form. Handling hazards and color have deterred broad usage. The development of a series of masterbatches by Albright Wilson should facihtate further use. 

Hydrocyclones are available in numerous sizes and types ranging from pencil-sized 10-mm diameters of plastic to the 1.2-m (48-in) diameter of rubber-protected mild or stainless steel. Porcelain units 25 to 100 mm (1 to 4 in) in diameter are becoming popular, and in the 150-mm (6-in) size the starch industry has standardized on special molded nylon types. Small units for fine-size separations are usually manifolded in multiple units in parallel with up to 480 ten-mm... 

Nylons belong to the class of polymers known as engineering polymers that is, they are strong, tough, and heat resistant. We can readily extrude and mold nylons to form a wide variety of useful objects, such as tubing, furniture casters, and automotive air intake ducts. Nylons are commonly spun into filaments or fibers. These can be used directly, or braided, or twisted to form threads, yarns, cords, and ropes, which may be further woven to make fabrics. In their fibrous forms, nylons are used in carpets, backpacks, and hosiery. 

We can nucleate crystallization from the melt by incorporating finely ground inorganic crystalline compounds such as silica. Nucleation of injection molded nylons has three primary effects it raises the crystallization temperature, increases the crystallization rate, and reduces the average spherulite size. The net effect on morphology is increased crystallinity. This translates into improved abrasion resistance and hardness, at the expense of lower impact resistance and reduced elongation at break,... 

Molded nylon-6,6 is used for lawn mower blades, bicycle wheels, tractor hood extensions, skis for snowmobiles, skate wheels, motorcycle crank cases, bearings, and electrical connections. Fiber nylon-6,6 is used in clothing, fabrics, and rugs ... 

Rotomolding. Nylon-6, nylon-11, and nylon-12 can be used in rotomolding and are generally supplied for these applications as a powder or with a small pellet size. The process involves tumbling the resin in a heated mold to form large, thin-walled moldings. Nylon-11 and nylon-12 use mold temperatures of 230—280°C and nylon-6 is processed at over 300°C. An inert gas atmosphere is preferred to avoid oxidation. 

Initial adhesion tests were made with 3.5- X 1- X 0.064-inch specimens of aluminum (Aluminum Associates No. 2024) and cold-rolled steel (polished ASTM A-415). Later tests were made with strips of copper, chrome-coated steel (Weirton Steel Co.), and brass with molded nylon 66 bars and with Mylar 300A poly (ethylene terephthalate) film. Before use, the specimens were washed (scrubbed with a soft bristle brush) with a solution of Alconox detergent, rinsed with water, rinsed with acetone, and dried. 

Now that three separate values for the failure torque have been found for this shaft, the logical question Is which (If any) of the answers Is correct. The answer to this question depends very strongly on the nature of the material Investigated. For very brittle materials (e.g., cast unplastlclzed polystyrene), experiments have shown that the maximum principal stress criterion gives quite reasonable results. For ductile materials such as molded nylon, experimental evidence Indicates that either the maximum shear stress or octahedral shear stress criterion Is more appropriate. 

The nylon casting process is relatively more economical and is a more practical technique for the production of large and thick parts than comparable extrusion and injection molding processes. In addition, the crystallinity and molecular weight of cast nylon are higher than those of extruded or molded nylon. Consequently, cast nylon has a much higher modulus and heat deflection temperature, improved solvent resistance, and better hygroscopic characteristics and dimensional stabflity. 

Nylon parts made by polymerization casting of caprolactam exhibit higher molecular weights and a highly crystalline structure and are, therefore, slightly harder and stiflfer than conventionally molded nylon-6. 

Monsanto Chemical Co. produce injection molded Nylon/ABS alloys (Triax) that are characterized by good toughness, high chemical resistance, and easy moldability. Applications of these alloys include industrial power tools, lawn and garden equipment housing and handles, gears, pump impellers, and car fascia. 

Kojima, Y, Usuki, A., Kawasumi, M., Okada, A., Kurauchi, T., Kamigaito, O., and Kaji, K., Novel preferred orientation in injection-molded nylon-6-clay hybrid, J. Polym. Sci. B, 33, 1039-1045 (1995). 

Mold Wiz INT-937 release agent, mold NR Nopco 1097A Perenol 1097A release agent, mold nylon Albrite TlOP... 

Since Nylon is a hygroscopic polymer, its plastic response was studied in three different states of relative humidity, namely in a 100%-dry state, in a state of 60% relative humidity, and in a water-soaked condition. The dramatic effect of different levels of relative humidity on the plastic resistance of compression-molded Nylon-6 is shown in Fig. 9.1. 

Fig. 9.1 Stress-strain curves for compression-molded Nylon-6 samples (1) fully dried at 100°C for 24 h in vacuum (2) conditioned at 60% relative humidity and (3) soaked in water (from Gal ski et al. (1988) courtesy of the ACS).

Fig. 14 X-ray diffraction photographs for the surface and inner of an injection-molded Nylon 6 bar 3 mm thick. For photographical conditions, see the legend of Fig. 13...

Figure 6.91 Stress vs. strain at various temperatures for BASF Ultramid ASK—easy flowing, injection molding Nylon 66 resin (DAM) [8],...

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