Bamboo Cable & Rope
Bamboo cable, comparable to steel in tensile strength was being used at minimum 2000 years ago.
Marco Polo described how the Chinese used and manufactured bamboo cables for towing boats.
Engineers experimenting for the Whangpoo Conservancy Board found out that these twisted and plaited bamboo cables were made with material taken from the outer layer of the bamboo (which was only 1/8 inch or 3 mm thick). They estimated that the working stress was about 20,000 pounds per square inch, which was of the same order as normally taken by steel wires of the same size.
The breakages were very few with bamboo cables. Moreover, while hempen ropes lose some 25 percent of their strength when wet, the tensile strength of plaited bamboo cables increases about 20 percent when they are fully saturated with water. Bamboo cables were available in lengths up to a quarter mile.
Bamboo cables were the earliest structural element in the history of engineering to be used for suspension bridges, which originated in western China and the Himalayas.
Primitive bridges made of bamboo cables droop across gorges with one end fixed lower than the other. Bamboo tubes greased with yak butter slide down the cables, with a cradle hanging from them in which people and animals side. Of great strength, a bamboo cable of 2 inch diameter could support 4 ton, these ancient bridges spanned distances up to 76 meters without central supports.
Later on, various designs combined whole bamboo culms, woven slats, and cables braided of workable species such as Gigantochloa apus, which was a favorite for bridges in Java.
The Anlan Bridge
The remarkable Anlan bridge on the Min River in China was first constructed around 300 AD. Historians consider this bridge one of the engineering marvels of the ancient world.
Bamboo cables have a tensile strength of up to 26,000 pounds per square inch, while hemp rope can only carry a stress of 8,000 pounds.
The Anlan suspension bridge spans the 1,000-foot wide Min River, is 9 feet wide, and was built entirely of bamboo cables resting on seven supports fixed equidistant in the bed of the stream. The floor of the bridge rested across 10 bamboo cables, each 21 inches in circumference, and five similar cables on each side form the rails.
Moreover, the silica-containing outer surface is very resistant to wear, e.g., against rock surfaces, which is naturally important both in towing and bridge cables.
Hand-Spun Bamboo Rope
Uses of Bamboo : Bamboo Cables
How to Plait or Braid Bamboo Cables?
Bamboo cables are made by first splitting bamboo canes over their entire length into thin strips. Once the strips are obtained, the soft inner layer needs to be removed from the silica-rich outer layer. A Nicaraguan bamboo basket maker demonstrates how to separate the inner from the outer layer in the video below.
Bamboo Basket Maker Nicaragua
Short video demonstrating how to remove the soft inner part of bamboo strips. Only the outer layer (silica-rich part) of the bamboo culm is used for bamboo basket making.
Technique Smart Bamboo Woodworking Skills Crafts
Bamboo splitting and making strips for weaving
Ancient Technology of Making Bamboo Crafts - Most Incredible Bamboo Woodworking Ever
METHOD FOR MANUFACTURING COMPRESSED AND HARDENED BODY OF BAMBOO FIBRES, AND COMPRESSED AND HARDENED BODY OF BAMBOO FIBRES MANUFACTURED BY SAID METHOD
Provided is a method for manufacturing a compressed and hardened body of bamboo fibres, said body exhibiting homogeneous mechanical strength and excellent design properties, as a result of a new bamboo fiber crushing technique and the adhesion effect associated with the capillarity of a thermosetting resin. A bamboo fibre aggregate is obtained by roller pressing cut bamboo pieces and separating some part of the cut bamboo pieces' fibres, and a non-separated fibre bamboo piece aggregate is obtained with remaining narrow bamboo pieces. A bamboo fibre mixture is then obtained by bringing together without separation the bamboo fibre aggregate of cut bamboo pieces and the non-separated fibre bamboo piece aggregate of narrow bamboo pieces to form one body. The bamboo fibre mixture is then subjected to processes such as: dry distillation, drying, immersion in a thermosetting resin, drying, compression molding, thermosetting to manufacture a compressed and hardened body of bamboo fibres.
Bamboo fiber production technology
The invention discloses a bamboo fiber production technology, which comprises the steps of 1) preparing scutching cotton; 2) combing cotton; 3) drawing operation; 4) rove operation; 5) spun yarn operation; 6) winding operation; and 7) yarn quality. Yarn quality index of bamboo/Tencel50/5014.7 tex blended yarn are as follows: weight CV0.65%, weight deviation +0.8%, single strength CV 10.8%, strip dry CV 14.7%, detail 57 pieces/km, slubbing 32 pieces/km, cotton junctions 54 pieces/km, twist irregularity 1.51%, and twist 92 twising/10cm. The welding technology has the advantages that the operation is reasonable; the manufacture cost is low; the parameter match is reasonable and coordinative; and product quality and production efficiency can be effectively raised.
Processes for the treatment of plant materials in the preparation of fibres
In obtaining fibres from fibrous tissues such as flax, hemp, sisal, ramie, and bamboo, the materials are subjected to the action of a 0.1-0.5 per cent solution of a neutral salt of one of the alkali metals or of ammonium. Neutral tartrates, citrates, oxalates, sulphates, and phosphates, which precipitate the alkaline earth metals with which the pectinous substances are associated, are preferred. As applied to ramie ribbons which should be comparatively fresh, the ionic exchange treatment may be effected with a 0.1-0.5 per cent ammonium sulphate solution at 1-2 atmospheres pressure for 60-20 minutes, and, after the removal of the pectinous complexes, the material is heated in an autoclave with a suitable alkaline solution, such as a 2-4 per cent caustic soda solution under a pressure of 6-10 atmospheres for 20-60 minutes in order to remove fats, waxes, cutaneous substances and resins impregnating or adhering to the fibres. The chlorophyll remaining is removed by bleaching and there is thus obtained a product consisting of the ultimate fibres. The alkali treatment may be repeated for a shorter period after bleaching and a strong lustrous product is obtained comparable in appearance with artificial silk but much stronger. Bamboo may be depectinized and then submitted to alkali treatment for a shorter period than ramie, and if while still moist, the softened outer layer or skin is removed, a product is obtained of great length and strength, suitable as a substitute for hemp, jute and the like in rope and sack manufacture. The fibre may be bleached, but this may occasion mechanical weakening. In treating flax straw, the material is boiled in a 0.1-0.5 per cent solution of ammonium sulphate at a pressure of 1-2 atmospheres for 60-20 minutes. The insoluble pectose is converted into soluble pectin. The straw is expressed, washed and dried, and then scutched &c. as is usual. The reagent may be used repeatedly until its colour is so dark that staining of the fibre begins after which it may be used for manure.
Manufacture process for recombined bamboo
The invention discloses a manufacture process for recombined bamboo. Raw materials are loaded and stacked. The manufacture process includes the following steps that A, the raw materials are dried, wherein the raw materials are placed under negative pressure to be dried till the moisture content is lower than 15%; B, high-temperature pyrolysis is conducted, wherein the temperature rises to 170-240 DEG C, vertical air flow with the wind speed being 2-10 m/s is formed in an accompany manner in a pyrolysis kiln, and the pressure inside and outside the pyrolysis kiln is kept equal by discharging gas till the pressure inside and outside the pyrolysis kiln is naturally equal; C, dipping is conducted; D, dipping drying is conduced, wherein the raw materials are placed under negative pressure to be dried till the moisture content is 7%-15%; E, management is conducted, wherein the raw materials are managed into bundles, and when the pressure which is perpendicular to the fiber direction, same in force application direction and same in magnitude is borne, the distance between thicknesses of all force application points on each single bundle of raw materials is smaller than 5%; and F, pressing solidification is conducted. The manufacture process has the beneficial effects that the utilization rate of the raw materials is high, the mechanical strength of manufactured recombined bamboo square stock is large, the production efficiency is high, and the one-time yield is high.