CAST NYLON 6 BIG PARTS
A large US manufacturer's mining division
designed a piece of prototype equipment destined for South America. An integral
component on this equipment was a sheave measuring 48 inches in diameter by 18
inches through the bore. The design parameters required the sheave to be light-
weight yet durable, corrosion resistant, and capable of operating in a harsh
mining environment. Cast Nylon 6 proved to be the solution.
Cast Nylon is produced by direct
polymerization of a monomer within a heated mold. This method allows for the
manufacture of castings of virtually unlimited size and with minimal internal
stress. Fillers and additives can also be introduced into the process, allowing
the manufacturer to formulate specialized grades to suit specific end use
Cast Nylon 6 has long been accepted as a
standard in many sheave applications. Common uses range from mobile construction
cranes to heavier offshore applications. Cast Nylon's light weight (1/7th that
of steel or cast iron), combined with its broad range of physical properties,
provide numerous benefits over cast iron and steel in countless applications.
The resilient nature of Nylon 6 provides for a larger point contact area between
sheave and wire rope, this allows Cast Nylon Sheaves to support loads close to
that of it's steel and cast iron counterparts. The lighter Cast Nylon provides
for easier installation, greater stability, and higher lifting capacities as
considerable boom weight is eliminated.
In addition, the combination of differing
mating materials between sheave and wire rope provide for a dramatic increase in
rope life. When rope diameters reach 4 inch, as in this application, even a
small increase in rope life can lead to big savings.
Engineered components, as large as those
shown above, provide few manufacturing options within the engineered
thermoplastics family. Cast Nylon 6, having custom-cast capabilities, proved to
be the logical choice. Through the use of specialized tooling and Nylatech MD, a
roughcasting that was close to the finished component dimensions was made. This
reduced the amount of material required by 30%, and saved considerable machining
time. Had the individual castings been produced as disks, they would have
weighed close to 1800 pounds each. As "custom-cast components" each
sheave weighed-in at 1200 pounds, making them two of the largest Cast Nylon
Castings ever produced in North America.
Submitted by Nylatech, Inc., manufacturers of
cast nylon 6 and 6/12 rod, sheet, tube, bar, and finished and semi-finished
custom cast components.
For more information, contact Calvin Petersen, Nylatech, Inc., P.O. Box 455, Everson, WA 98247, 800-506-9566, Fax:360-966-2838, E-mail:
firstname.lastname@example.org, Web: www.nylatech.com.