Fusing Synthetic Rope
Fusing a Rope is simply the melting of the synthetic fibrous ends of the rope so they will not continue to fray. The melting of these fibers can be achieved by flame, an electrically heated element, or a soldering iron.
A Note About Fusing Synthetic Rope
According to Animated Knots:
For rope made of nylon, polyethylene, polyester, or polypropylene, the ends can be protected moderately well by melting them using flame, an electrically heated element, or a soldering iron. However, merely cutting the rope with an electrically heated element provides very poor protection: the thin layer of fused plastic does not survive compression or abuse. Careful, prolonged heating provides better protection by creating a larger layer of solidified plastic on the end of the rope. However, nothing beats adding a properly applied whipping. If you value your ropes, whip and burn all their ends.