NYLON REACHES SWEET SIXTEEN (Aug, 1954)
Remember when nylon meant wartime queues lined up for scarce hosiery? Nylon means many things todayâ€”brushes and gears and egg beaters. Let’s look at this amazing plastic once more as
NYLON REACHES SWEET SIXTEEN
By Robert E. Paquin
NYLON, A COMMONPLACE WORD today, is just 16 years old, yet to many it seems as if it has always been here. For only 14 years it has adorned feminine legs, but today this tough, durable chemical has invaded a variety of industries. Molded-nylon components now go into everything from egg beaters to motorcars. Nylon’s amazing toughness and resistance to wear, even when lubrication is nonexistent, have made it a first-class engineering material. New uses for the versatile plastic are being found daily.
In the automotive industry nylon is used in distributor, speedometer and windshield-wiper gears, small bearings, cams and clutch and brake-pedal bushings.
The interior lamps of many cars have lenses molded of .025-inch-thick nylon. The inherent toughness of nylon enables the thin lenses to withstand rough treatment both in assembly and service. Nylon resists the heat of the lamp and will not turn yellow with age.
One manufacturer adopted nylon for the speedometer take-off gear. The material is molded directly on the gear shaft in one operation, as compared to five separate production operations formerly required. This resulted in a 50-percent reduction in cost and improved performance.
Nylon has entered the home in the form of tough, easily sterilized combs, brush backs, tumblers, nursing-bottle funnels and kitchen utensils. Nylon rollers and slides for kitchen cabinets and stove drawers will operate for the life of the equipment with no lubrication. An added advantage is their smooth, silent operation. Nylon buttons and zippers won’t break, are colorful and resist dry-cleaning solvents and ironing temperatures. Mixing-machine gears, washing-machine and fan parts, refrigerator-door rollers, cutlery handles, rollers and slides for windows and draperiesâ€”all these now contain nylon.
In an electric shaver, a durable nylon connecting rod transmits power from the motor shaft to the cutter blade. The connecting rod reciprocates at speeds of 15,000 to 17,000 half-cycles per minute with almost no lubrication. Nylon’s ability to absorb vibration makes it ideal for many such high-speed applications.
High-quality egg beaters are provided with nylon gears which last 20 times longer than the metal gears previously used. The nylon gears operate more silently and efficiently and are not affected by salad oils and food acids. No lubrication is used.
Designed for both industrial applications and in the home workshop, a metalworker’s hammer with resilient nylon faces will not mar the softest metal. In actual tests, made by pounding the nylon faces with sharp objects, it lasted 24 times longer than the next-best material tested.
Designers of business machines have turned to tough but attractive nylon for their difficult parts. One calculating machine features nylon dials, ratchets and cams. An intricate cam, now molded in a single operation, formerly required 20 production steps for its manufacture. Smoother operation and elimination of the need for lubrication point to more and more business-equipment parts made of nylon. For-example, a manufacturer of filing cabinets now equips them with noise-reducing nylon rollers.
Medical uses include hypodermic-needle parts, surgeon’s scrub brushes, inspiratory valves and components for blood-transfusion apparatus. Nylon’s physiological inertness and its ability to undergo repeated sterilization in a steam autoclave make it an ideal material for these and numerous other surgical and medicinal uses.
One class of aircraft uses 16 miles of nylon-covered cables and wires in each plane. The nylon covering protects the wires from gasoline and oil and resists abrasion. It also affords protection against fungi and heat. Because of nylon’s toughness and wear resistance, thinner, lightweight coatings can be used.
Other aircraft uses for nylon include grommets, wire connectors, switch components, self-locking nuts, insulated tools and mechanical parts.
In hydraulic equipment, the plastic has been found to be perfect for valve seats, as its resiliency allows it to form a tight seal even where slight irregularities in the mating surfaces exist. Look for it in the form of faucet washers in the near future.
Invading the photography field, nylon is now used for gears, cams and bearings for cameras and projectors, where its cushioning action and freedom from lubrication problems make it a welcome new material. Nylon is not a trademark. It is the generic name for a group of compounds of polyamide resins which are related, but not identical, in chemical composition. Since it is a thermoplastic, articles molded from it can be reheated and reshaped numerous times without injury to the plastic. Thermosetting plastics, the other major type, cannot be resoftened.
Nylon was first synthesized by Du Pont chemists in the early 1930s, and research continued until its first introduction to the general public in 1938 in the form of toothbrush bristles. Its nationwide debut in women’s hosiery came in 1940 and met with prompt and overwhelming success.
Nylon molding powders were introduced to the plastics industry in 1941. Constant research and development since that time has brought forth the host of present-day applications. FM-10001 nylon is the most widely used type for injection molding. The most heat-resistant member of the nylon family, it is particularly suited for gears, cams and bearings.
The most flexible nylon material is the FM-8001, which until recently could not be molded or extruded by conventional processes. These limitations have now been eliminated with the development of an improved molding powder which can be processed by any of the common techniques.
When used indoors under normal conditions, nylon undergoes no appreciable change in long service. It does not deteriorate, nor is it subject to attack by fungi, rodents or insects. Exposed to direct flame, nylon will burn slowly, but it is self-extinguishing upon removal of the flame.
The color of articles molded from the various grades of nylon ranges from cream to light amber. Some types are translucent in thin sections. FM-6501 nylon can be made transparent by extruding the plastic directly into cold water.
A wide range of colors can be molded into some types of nylon. Solid parts can also be dyed by immersing the article in a boiling-water solution of the same dyes used for coloring nylon fabrics. Colors obtained by this method are resistant to boiling water and hot, soapy water.
Combining as it does a host of valuable properties, the future of nylon as an engineering material seems assured. There is little reason to doubt that hundreds of new uses will be discovered for this amazing plastic. * * *