How Rope is Made

Heat Polypropyline Resin

Rope manufacturers buy polypropyline resin pellets from chemical plants. After adding colorants and other ingredients, the resin mixture gets heated to 450 degrees Fahrenheit. At this heat, the colored resin can be pushed through an extruder, which is like a gigantic pasta-making machine. The resin comes out of the extruder through a lot of tiny holes in long thin hot sticky fibers.

Stretch and Strengthen the Fibers

These hot fibers must be plunged immediately into a vat filled with cold water. As the fibers cool, the resin also loses its tackiness. Next, the fibers pass over a godet. This is a very large metal spool on which the thread can be reheated, this time to 300 degrees Fahrenheit. It also gets stretched until it reaches at least four times its original length. Unlike what happens when a rubber band gets stretched very thin, these fibers actually gain strength as they get heated and stretched.

Twist the Fibers into Rope

After leaving the godet, the fibers move first to twister machines and next to rope machines. There, fibers are wound together to form rope. The number of strands that make up the rope is indicated on the rope's package as ply (two strands is two ply, three strands is three ply, and so forth). Then, the finished rope gets cut into lengths, placed in packaging and shipped to the customers.

Resources

• Illustrated Rope Manufacturing Process