Classifications

• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B1/00—Constructional features of ropes or cables
  • D07B1/02—Ropes built-up from fibrous or filamentary material, e.g. of vegetable origin, of animal origin, regenerated cellulose, plastics
• • D—TEXTILES; PAPER
  • D07—ROPES; CABLES OTHER THAN ELECTRIC
  • D07B—ROPES OR CABLES IN GENERAL
  • D07B2201/00—Ropes or cables
  • D07B2201/20—Rope or cable components
  • D07B2201/2001—Wires or filaments
  • D07B2201/2009—Wires or filaments characterised by the materials used

Definitions

• the man-made synthetic fibers in general possess superior strength and abrasion resistance compared with the natural vegetable fibers, they are considerably more costly than the natural fibers and, in the form of ropes and the like made of continuous filaments, have a 2) number of disadvantages.
• the slippery feel is unattractive in use, particularly to those accustomed to handling vegetable fiber ropes and the like.
• the process of our invention offers a number of advantages over processes already described for producing ropes and the like from either natural long vegetable fibers or continuous synthetic filaments.
• One of the most important advantages is that the synthetic fibers of our invention may be processed, either alone or mixed with the natural fibers, directly on the usual machinery used for preparing and spinning natural long vegetable fibers into yarn and for this reason blending with the natural fibers to produce a uniform yarn is simply effected.
• Furthermore by the process of our invention it is possible, without any modification of the conventional process to produce a yarn of the approriate size for construction of twine, cord or rope, whereas with continuous filament yarns of synthetic polymers a number of additional plying operations are required to produce an adequate yarn.
• ropes and the like prepared according to our invention from mixtures of natural and synthetic fibers have a number of advantages over those prepared from all natural or all synthetic fibers. For example blending of the natural fibers with the stronger synthetic fibers improves the strength of the product over that of a comparable all vegetable fiber product, to an extent dependant upon the proportion of synthetic fibers used. Although this increased strength would be expected to lead to a proportional increase in the life of the rope in use, we have found, surprisingly, that ropes and the like, made by the present process have a life greatly in excess of this expectation.
• a four strand rope of 3%" circumference made according to this invention from a 50/50 mixture of sisal and isotactic polypropylene (40" staple length 0.005 diameter fibers) has 20% less weight per unit length than an equivalent size of all sisal rope together with a 25% improvement in strength.
• This sisal/polypropylene rope in use as a quarter rope in deep sea trawling operations gave a lifetime of 6 to 8 times that of the all sisal rope, very much in excess of expectation.
• two ropes of similar size were compared in use as tail ropes in river barge towing which are subject to high abrasion together with alternate wetting and drying cycles.
• One rope was all sisal and the other 50/50 sisal/polypropylene.
• the mixed rope gave a life of 6 times that of the all sisal rope.
• a further advantage of the blended natural/artificial fibre ropes of the present invention is that such ropes do not swell to the same extent as all natural fiber ropes. Such swelling when the rope is subjected to successive wetting and drying cycles leads to unlaying of the natural fiber rope structure with consequent reduction of abrasion resistance and life. This effect is substantially absent in the ropes of the present invention due to their reduced swelling propensity.
• the density of the product may be controlled by adjustment of the proportions of natural and synthetic fibers, so that the product will sink or float in Water as desired.
• Ropes and the like constructed from a blend of natural and synthetic fibers do not suffer from the deficiency of forming a glazed or smooth surface when subjected to frictional heat, for the natural fibers serve to keep the fusible synthetic fibers apart and so prevent the formation of a continuous glazed surface.
• the water retention of the wet natural fibers is often sufiicient to assist cooling or lubrication of the rope and further prevent fusing of the synthetic fibers.
• the cross section of the fibers is substantially circular, to impart a small amount of crimp to the synthetic fibers of about -20 percent crimp as expressed by the relation where L is the length of the filament with the crimps present and L is the length of the same filament when extended just sufliciently to remove the crimps.
• L is the length of the filament with the crimps present
• L is the length of the same filament when extended just sufliciently to remove the crimps.
• changing the cross-sectional shape of the synthetic fibers has a beneficial effect on the ease of processing the fibers, alone or mixed with natural fibers into ropes and the like.
• fibers having a more or less flattened cross section as for example rectangular or square sections
• fibers having a more or less flattened cross section as for example rectangular or square sections
• hemp, manila and sisal and of lesser importance are ramie and flax in the longer forms.
• the natural and synthetic fibers are combined in as uniform a manner as is practical in the spinning operation to produce the yarns and when the rope or the like has been completed no after treatment by heat is necessary to stabilise the lay of the rope, such as is necessary when a rope is made entirely of continuous synthetic filaments.
• a rope of three inches circumference from a 50/50 blend by weight of sisal and isotactic polypropylene fibers the latter having a length of 40 inches, a diameter of 0.005 inch, and a tenacity of 7.0 grams per denier.
• this rope was subjected to a load equivalent to 75% of its breaking load, that is to a load of 3.9 tons, it was found upon close examination after releasing the load that the sisal fibers, which originally had a length of about 40 inches, were broken into short lengths of 1-2 inches corresponding approximately to the distance between successive turns of the polyproylene in the twisted yarn.
• the following table illustrates the properties of ropes, all 3 inches circumference, prepared on conventional long vegetable fiber spinning and rope laying machinery from the synthetic fibers and blends of the present invention. Also included for comparison are the properties of ropes of the same size. constructed from natural fibers or continuous multifilament synthetic fiber yarns.
• Nylon multifil 5 d.p.f 8. 0 6.0 3.0 11.0 194 75 37 8.
• Polyethylene 0.010 diam. mono 6.0 4.
• L 2. 2 5. 5 143 73 37 1 Minimum for B.S.S. Grade 1. 2 Minimum B.S.S. value.
• the thickness should be between 0.001 and 0.020 inch.
• thickness is here meant the diameter of a circular fiber or any linear cross-sectional dimension of non-circular or flattened fibers. Fibers having a rectangular cross-section in which one dimension is about three, times the other are particularly suitable.
• Natural fibers suitable for use in the process of our invention are any of those usually called long vegetable fibers and commonly used for production of ropes and In this table conversion efficiency is the ratio of breaking strength, for example of the rope yarn, to that of the initial fibers expressed as a percentage.
• the size of the filaments comprising the multifilament yarns is expressed in the usual wayas denier per filament of d.p.f.
• Ropes and the like composed of spun rope yarn which is 20 to 100% by Weight of synthetic fibers blended with to 80% of long vegetable fibers, said synthetic fibers being cut of length between 25 and 80 inches and having a thickness between 0.001 and 0.020 inch.
• the synthetic fibers are selected from the group consisting of stereoregular polyolefines, polyesters, copolyesters, polyamides, polyvinvyl chloride, polyvinyl alcohol and acrylic polymers.
• Ropes the like according to claim 1 wherein the long vegetable fibers are selected from the group consisting of hemp, manila, sisal, ramie and flax.

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• Ropes Or Cables (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=26250107

Family Applications (1)

Country Status (2)

Cited By (2)

Citations (9)

• 1963
  • 1963-04-02 NO NO148178A patent/NO117287B/no unknown
  • 1963-04-03 US US270156A patent/US3205649A/en not_active Expired - Lifetime

Patent Citations (9)

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