Hemp rope

Galeopsie). -ol, n. hemp (seed) oil. -papier, n. hemp paper, -samen, n., -saat, /. hemp-seed. -saure, /. linoleic acid, -sell, n. hemp rope, hemp cord. 

Cannabis is one of civiiization s oidest cuitivated nonfood plants, and does not seem to exist anymore in its wiid form (figure 10.1). In addition to its psychoactive effects, the cannabis plant has also been used for its fibers. Hemp fibers have been found in China dating from 4000 B.C.E., and hemp ropes were dated to 3000 B.C.E. in Turkestan, but it is not certain that cannabis was used for psychoactive purposes at those piaces and times (Schuites and Hofman 1992). 

Hemp rope, once widely used, has largely been replaced by iiylon cord. The flexibility and mechanical strength of hemp, a nettle plant fiber, also characterize nylon synthetic and several other inorganic fibers in common use. 

Leonard Fuchs woodcut of Cannabis sativa in an early herbal from 1543. This plant is the main source of marijuana, a mixture of its leaves and flowers, and of hashish, made from the resin in its flowers. This plant is also grown for its strong fibers, which have been used in producing hemp rope, fabrics and fine papers. 

These items are also described in Lancaster s book on page 106, They are so named because the fire dust sparks drop to remind us of waterfalls. They are prepared as follows(Fig.129) Charge a waterfall composition which contains aluminium powder of relatively large flakes into strong paper tubes which have a thin wall which burns away. (See also 15.10.) Put a quantity of ignition composition in the end of each tube. Make holes in it from the outside and pass a piece of wire which is wound with a piece of powder pasted paper through the hole. Fix the waterfall units made in this way to a hemp rope at intervals of about 50 cm. Connect the igniting ends with a line of piped quick match. 

Cannabis in one form or another has been found in other parts of Europe as well during this early period of history. Hempen ropes, for instance, have been found in a well from a Roman fort in Dunbartonshire, Britain, which was occupied between A.D. 140 and 180. However, modem scientific studies of pollen in soil samples shows that cannabis was not cultivated in England until around A.D. 400 when the Anglo-Saxons migrated to the island from their homes in mainland Europe. Since they had no way of knowing if there would be enough cannabis in the lands they conquered to meet their needs, the Romans took hemp ropes with them. When these ropes wore out, orders were sent back home for replacements. The pieces of hemp rope from Dunbartonshire were thus made elsewhere and sent to England as part of the supplies needed for the occupation. 

Oakum Loose fiber obtained by untwiating and picking old hemp ropes. It was used especially for calking the seems of ships. 

Table 8.16 shows dry and wet strength of ropes made from ramie, jute, sunn, kenaf, and roselle. In each case, wet strength shows some improvement. Prolonged storage of sunn and Italian hemp ropes in water deteriorates their strength (see Table 8.17) the deterioration in sea water is much more drastic. Deterioration due to prolonged storage may be attributable to microbial action on fibers. 

Another application is to estimate the mechanical advantage of a capstan. The static coefficient of friction when slip is impending for hemp rope on steel is about 0.25. For four complete turns about the capstan (a = 25.1 radians), the value of T /T2 from Eq. (2.16) is ... 

A cross-sectional view of hemp fiber is shown in Figure 3b. It has a Z twist in contrast to the S twist of flax. Hemp is regarded as a substitute for flax in yam and twine. Its eadier use in ropes has been replaced by leaf and synthetic fibers. Hemp fiber is used in Japan, China, CIS, and Italy to make specialty papers, including cigarette paper, but bleaching is difficult. The fiber is coarser and has less flexibiUty than flax. 

Seventy years ago, nearly all resources for the production of commodities and many technical products were materials derived from natural textiles. Textiles, ropes, canvas, and paper were made of local natural fibers, such as flax and hemp. Some of them are still used today. In 1908, the first composite materials were applied for the fabrication of big quantities of sheets, tubes, and pipes in electrotechnical usage (paper or cotton as reinforcement in sheets made of phenol- or melamine-formaldehyde resins). In 1896, for example, airplane seats and fuel tanks were made of natural fibers with a small content of polymeric binders [1]. 

C. sativa is cultivated for several purposes. Actually, the main legal purpose is the production of hemp fibers and pulp. From these materials paper, clothes and ropes are made [12] and several Western coimtries have already legalized the cultivation of C. sativa for these purposes. In research, the drug-type of C. sativa is also cultivated, however, only for the investigation and determination of forensic studies for chemotype separation. The growth for medicinal purposes is hardly performed, hi the Netherlands C. sativa is cultivated for medicinal purposes under strictly controlled regulations by the company Bedrocan. In this chapter we discuss basic aspects of the cultivation of C. sativa and the optimization of THC content in the plant. 

Nature has long used reactions such as these to produce interesting solids such as cotton (seed pod), hemp (grass), and silk (cocoons for worms while they develop into moths) as fibers that we can strand into rope or weave into cloth. Chemists discovered in the early twentieth century that cellulose could be hydrolyzed with acetic acid to form cellulose acetate and then repolymerized into Rayon, which has properties similar to cotton. They then searched for manmade monomers with which to tailor properties as replacements for rope and sdk. In the 1930s chemists at DuPont and at ICl found that polyamides and polyesters had properties that could replace each of these. [Linear polyolefins do not seem to form in nature as do condensation polymers. This is probably because the organometaUic catalysts are extremely sensitive to traces of H2O, CO, and other contaminants. This is an example where we can create materials in the laboratory that are not found in nature.]... 

Hemp Fiber (Chanvre in French). The bast-fiber obtained from the plant Cannabis indica or C sativa, which is a perennial herb (Ref 1). The plant is native of western and central Asia, but has long been cultivated in Brazil and tropical Africa, and is now extensively cultivated in many countries. Its fiber is used for preparation of ropes and paper, but was also proposed by Trench (Ref 2), in 1877 to be nitrated to an explosive Refs 1) Daniel (1902), 773 2) Webster s 7th New Collegiate Diet (1969), 388... 

The simplest grommet consists of a piece of rope, looped at each end and wrapped once directly over the rotating band or in front of it, or in case of double-banded shell, between the bands. After this the hemp twine is drawn tightly thru the two end loops and secured by a "slipknot" (Knot designed to slide or pull free under strain)... 

Hemp was grown in Colonial and Revolutionary America. Indeed, farmers were sometimes required to grow hemp because it was used to make ropes for the sailing ships that were the lifeblood of international commerce and military power. 

Virginia colonists begin to plant hemp (marijuana). Its main use, however, will be making rope for ships. 

I echnological feats are made possible only after the appropriate materials 1 have been developed. Columbus made it to the Americas with rugged sails of canvas, firm ropes of hemp, and a sturdy wood hull bound by metal. Likewise, whether our dreams are to remain fiction or turn into fact depends on the materials available to us. Today, with a growing number of remarkable materials, we can send data through fiber-optic cables, crisscross the skies, or fly to Mars and beyond—a sign that the human spirit of exploration is more empowered than ever before. 

Bast or Bass is the fibrous inner bark of linden, lime and some milkweed trees. It is used for ropes, mats, peasant shoes(such as Rus"lapti"). The term blast fiber is applied to fibers obtained from the inner bark of flax, hemp, jute, ramie, etc. They contain a considerable amt of cellulose and can be nitrated to NC. However, these substances are more valuable as fabric materials than as sources of NC. Ramie has been used in France for prepn of pure NC Ref J.T.Marsh F.C.Wood, "An Introduction to the Chemistry of Cellulose",Chapman Hall, London( 1945), 1,3 12... 

After the American Revolution, American settlers continued to grow hemp of excellent quality in the land now known as Kentucky. Hemp fiber continued to be a cash crop, the source of rope that rigged many of the world s sailing ships, and the rugged fabric that covered settlers wagons as they made their way westward. Canvas, another hemp product, was widely used for sails in the shipping industry. A remarkably durable cloth, it is one of the few that seawater does not rot or mildew. (The word canvas is rooted in cannabis. )... 

The hemp plant, Cannabis sativa, has been known for its commercial use as a source of hemp for the manufacture of rope, sacking and so on for well over 2000 years. The hemp seeds have also been used as a source of oil, as an animal feed and as a form of soap, while the leaves were first used in China because of the psychoactive ingredients they contained. From China, the... 

Marijuana use dates back to prehistoric times. Only one species of the plant, Cannabis sativa, yields both a potent drug and hemp, a strong fiber that is used in the manufacture of rope, canvas, and linen. Americans grew Cannabis sativa for its fiber for many years. —... 

It was once a patriotic duty for an American farmer to grow marijuana (hemp). In 1942 a film called Hemp for Victory was produced and distributed by the U.S. Department of Agriculture to encourage U.S. farmers to grow cannabis for much-needed hemp products, particularly rope. During World War II, narcotic drug use reached its twentieth-century low point in the United States. This was due to a continual decline in use as well as diminished supply due to disrupted international transportation. 

Fibers are used in a wide variety of applications and are composed of diverse materials. Natural animal and plant fibers, including wool, silk, cotton, hemp, ramie, flax, jute, and sisal, have long been used for clothing, baskets, fishing nets, and rope. Ropemaking has been an essential skill for thousands of years, a key element in the advancement of civilizations via the oceans. The natural mineral fiber asbestos is in the silicate family. We have encountered glass fibers previously in the text (see Chapter 7). 

---