professional factory for Deneema Marine Rope - 4mm – 56mm 3 Strand Twisted Polypropylene PP Ship Marine / Boat Mooring Rope – Florescence

A lightweight fibre that is also cheap. Farmers use it for bailer twine. From a sailor’s point of view polypropylene has the great advantage of being less dense than water. Not only does it float, but it refuses to absorb water too. Unfortunately it is not very strong and doesn’t offer much resistance to stretch. Left outside in the sun it deteriorates quickly. Polypropylene melts at a low temperature and it’s easy to generate sufficient frictional heat to cause damage or failure.

Despite its many apparent weaknesses, polypropylene finds many applications on dinghies and yachts. Where it is necessary to have a large diameter rope for handling purposes polypropylene is ideal due to its low weight and minimal water absorption. Where strength is not an issue (eg dinghy mainsheets) it can be used alone while more demanding applications will use a high strength core inside a polypropylene cover.

Polypropylene’s ability to float on water is, however, its most valuable attribute for the sailor. Used in applications from rescue lines to dinghy tow ropes it remains on the surface resolutely refusing to get dragged into propellers or lost under boats. While most users will be interested in the fine spun soft finished family of polypropylene ropes, dinghy sailors whose class rules require them to keep a tow line on board should look out for the harder finished rope intended for water-ski tow lines. Apart from being slightly stronger than the fine finished material, it traps minimal amounts of water between the fibres, keeping weight to a minimum.