 |
 |
Cordage:from public utilities and newspapers to the recreation, agriculture and transportation industries, it is essential to daily operations. At Make a mental note to notice how rope, cord and twine are intertwined with your daily life (and language!). We think you'll be surprised Rope and twine date back to prehistoric times, the first being made of vegetable fibers, either single strand or multiple strands twisted together. This beginning evolved into some of the natural fiber ropes and twines still used today: manila, sisal, true hemp, jute and cotton. While natural fibers still comprise a high percentage of cordage products used throughout the world, synthetic fiber products now enjoy the lion's share of the market here in the U.S. Some of the same constructions learned through the ages in the production of natural fiber ropes and twines are now used with synthetic fibers. Natural Fibers Manila is the premium natural rope fiber. It comes from the leaf stem of the Abaca plant, found primarily in the Philippines. Sisal comes from the leaf of the agave plant, native to South America, the East and West Indies, and Africa. Sisal is three-quarters as strong as manila. Hemp comes from the stem of the cannabis plant, found in Europe, Asia and the U.S. Jute is made from the leaves of the jute plant, found mostly in Pakistan, India and Thailand. It is weaker than manila, sisal or hemp, and is primarily used in twine for packaging and gardening. Cotton, grown throughout the world, is spun into yarns and used mostly in clotheslines, sash cords and twines.
If your cordage needs fall within the performance parameters of a natural fiber product, by all means, buy one. Most natural fiber ropes and twines have the advantage of not being a petrochemical product (more environmentally-friendly, depending on pesticides, etc., used to produce the raw material), and the potential to be produced in lower-tech, local manufacturing processes. Synthetic Fibers: The most common synthetic fibers used in rope, cord and twine are: Nylon: the strongest rope in general use today. It has high tensile strength, elasticity, energy absorption and impact resistance, a high melt point, and good abrasion resistance. It resists rot, chemicals and marine growth. Nylon rope is used where stretch is desirable, such as mooring a boat, and mountain climbing/rappelling. Polyester (widely known under the trade name "Dacron"), has all the properties of nylon, but has low elastic elongation. It is used in applications where stretch is not desirable, such as in sailing or with a block and tackle. Of all fibers, natural or synthetic, polyester has the best resistance to ultraviolet degradation. It is superior to nylon in wet abrasion. Polypropylene, the most widely-used rope in the United States, is weaker than nylon but still significantly stronger than the strongest natural fiber. It is lightweight and bouyant, with low elastic elongation, a relatively low melting point, only fair abrasion resistance, and is the most subject to ultraviolet deterioration (along with polyethylene). Polyethylene has the same characteristics as polypropylene, but is weaker and has an even lower melting point.
Types of ConstructionCordage products come in three basic types: braided, twisted and plied. All of these constructions may be done with a variety of natural and synthetic fibers, each type of construction and fiber having basic features that favor it for certain applications. Braided cords and ropes: Braiding is a variation of weaving that interlocks fibers to make cords and robes that will not unravel, turn under a load or kink. Braided cords and ropes may be made with or without a center filler for additional diameter and strength.
- Hardware Hotline May, 2000
| ||||||||||||||||||||||
BACK
TOP