Patent Application
20140272409
The present invention relates to fibers for forming rope structures and, in particular, fibers for forming rope structures having a desirable lubricity.
Rope structures are made of fibers that extend at least partly along the length of the rope structure. The fibers may be natural or synthetic. The present invention is of particular significance when applied to synthetic fibers, and that application of the present invention will be described herein in detail. However, the present invention may, in some forms, have application to natural fibers used in rope structures.
In general, the operating characteristics of the fibers forming a rope structure will form the basis of the operating characteristic of the rope structure formed thereby. As examples, operating characteristics of a particular rope structure, such as tensile (or ultimate) strength (maximum tensile load that the rope structure can withstand before failing or breaking), modulus of elasticity (tendency of the rope structure to be deformed under tensile loads), tenacity (breaking strength of the rope structure divided by the denier), weight per unit length, and wear resistance, are all determined at least in part by the same characteristics of the fiber structure or fiber structures used to form the rope structure.
In this context, it should be apparent that the surface characteristics of a rope structure will be determined at least in part by the surface characteristics of the fibers used to form that rope structure. For example, the coefficient of friction of the fibers used to form a rope structure will, in large part, determine the coefficient of friction of the rope structure itself. To obtain a rope structure with a particular coefficient of friction, it is known to provide fibers made of material having a corresponding coefficient of friction.
Accordingly, to obtain a rope structure with a low coefficient of friction, it is known that fibers made of a material having a low coefficient of friction may be used to form the rope structure. However, materials having a low coefficient of friction do not necessarily yield fibers and/or rope structures having other properties, such as tensile strength, modulus of elasticity, tenacity, weight per unit length, and wear resistance, required for a particular use environment. In addition, materials having the lowest coefficient of friction, such as polytetrafluoroethylene (PTFE), tend to be expensive, and rope structures made of PTFE fibers are thus correspondingly expensive.
It should be noted that, in addition to affecting the interaction with the rope structure and an external structure, the surface characteristics of the materials forming fibers used to form a rope structure affects the interaction of fibers within the rope structure. In particular, fibers within a rope structure mechanically engage each other such that, when the rope structure is used, these fibers move can abrade each other, especially at bend regions. Fibers having a high coefficient of friction may thus wear on each other on the interior of the rope structure, possibly reducing the useful life of the rope structure.
A number of techniques have been developed to create a rope structure having surface characteristics that differ at least in part from that of at least some of the fibers forming the rope structure. While some of these techniques are designed to improve surface characteristics such as wear resistance, techniques designed to improve coefficient of friction associated with the rope structure are most relevant to the present invention.
Initially, it may be possible to combine fibers such that the mechanical properties of the rope structure yield an effective coefficient of friction that differs from the coefficient of friction of the material forming the fibers. This approach may limit the techniques for combining the fibers and is only of marginal effectiveness at reducing the coefficient of friction of the rope structure relative to that of the fibers.
As another example, a rope structure may be made of a blend of fibers having different operating characteristics. For example, a rope may be made of a first fiber selected primarily based on tensile strength and a second fiber selected primarily based on coefficient of friction. In this case, the effectiveness of the second fibers at decreasing the coefficient of friction of the rope structure may be increased by forming the rope structure such that the second fibers are concentrated on the surface of the rope structure. Rope structures comprises of blends of fibers require the use of at least some of the expensive, low coefficient of friction fibers and may limit construction techniques available to the rope designer. And unless the proportion of second fibers to the first fibers reaches a critical portion (or volume), the second fibers may not improve the interactions among the first fibers within the rope structure.
As yet another example, a core rope structure comprising fibers selected primarily based on strength may be jacketed by a second rope structure comprising fibers selected primarily based on surface characteristics such as coefficient of friction. Rope structures comprised of a core rope structure and a jacket rope structure require the use of at least some of the expensive, low coefficient of friction fibers, limit construction techniques available to the rope designer, and may yield a rope structure that is not suitable for many use environments. The use of a jacket rope structure further does not affect the interaction of fibers within the core rope structure.
Another method of altering the surface characteristics of the rope structure is to apply a coating to the rope structure. The rope structure is made of fibers selected for a desired set of operating characteristics such as tensile strength and/or modulus of elasticity and the coating is formulated to yield desirable surface characteristics such as coefficient of friction. Application of a coating to a rope structure may undesirably change other operating characteristics of the rope structure such as weight per unit length and does not affect the interaction of fibers within the rope structure.
The need thus exists for rope structures, systems, and methods having desirable blend of the following design considerations: surface characteristics; fiber to fiber interaction within the rope; full range of rope construction techniques; operating characteristics; and low cost.
The present invention may be embodied as a fiber structure for forming a rope structure has a base matrix of base fiber material and at least one lubricity portion of lubricity material. The lubricity material determines a lubricity of at least a portion of a surface of the fiber structure.
The present invention may also be embodied as a method of forming a fiber structure for forming a rope comprising the following steps. A base fiber material and a lubricity material are provided. A fiber structure is formed such that the fiber structure comprises a base matrix formed of the base fiber material and at least one lubricity portion formed of the lubricity material such that the lubricity material defines a lubricity of at least a portion of the base matrix.
The present invention may also be embodied as a method of forming a rope structure comprising the following steps. A base fiber material and a lubricity material are provided. A plurality of fiber structures are provided, where each fiber structure comprises a base matrix formed of the base fiber material and at least one lubricity portion formed of the lubricity material such that the lubricity material defines a lubricity of at least a portion of the base matrix. The fiber structures are combined to form a plurality of yarns. The plurality of yarns are combined to form the rope structure.
Rope structures of the present invention may be manufactured using a number of manufacturing systems and methods, and several example rope manufacturing systems and example fibers and rope structures created by those manufacturing systems will be discussed herein.
I. First Example Manufacturing System, Fiber, and Rope Structure
Referring initially to
The material hopper 30a contains a base fiber material in the form of first pellets, grains, or powder 40 (hereinafter referred to as “base pellets 40” and indicated by right cross-hatching) and a lubricity material. The lubricity material may be in solid, liquid, or flowable form in the material hopper 30a. In the first example manufacturing system as depicted, the lubricity material takes the form of second pellets, grains, powder, or liquid 42 (hereinafter referred to as “lubricity pellets 42” and indicated by left cross-hatching).
The example base pellets 40 of base fiber material and lubricity pellets 42 of lubricity material are indicated by round or oval figures of equal size in
As generally described above, the present invention is of primary significance when applied to man-made or synthetic fibers, so the example base fiber material may be at least one material selected from the group of materials: Nylon, Polyester, Polypropylene (PP), Olefin, Polyolefin, Polyethylene (PE), Polyacrylonitrile, Carbon, Aramid, PBO (Poly(p-phenylene-2,6-benzobisoxazole), LCP (Liquid Crystal Polymer), PIPD (Poly[2,6-diimidazo(4,5-b:4′,5′-e) pyridinylene-1,4(2,5-dihydroxy)phenylen]), PBI (Polybenziadazole), PEN (Polyethylene Naphthalate), Glass, Basalt, Metals and metal alloys, PVC (Polyvinyl Chloride), PVDC (Polyvinylidene Chloride), Polyurethane-polyurea, Polyvinyl Alcohol, PPS (Polyphylene Sulfide). The example base pellets 40 of base fiber material is typically in granular or powder form when in the example material hopper 30a.
The lubricity material is a material that may be combined with the base fiber material such that a coefficient of friction of fibers formed of the base fiber material and the lubricity material is different from a coefficient of friction of fibers made from the base fiber material alone. Examples of materials that may be used as the example lubricity material include one or more of the following materials: Wax, Hydrogenated polyolefins, Silicones, Fluorocarbons, Graphite, Molybdenum Disulfide, Tungsten disulfide, Polyalpha-olefin (PAO), Synthetic esters, Polyalkylene glycols (PAG), Phosphate esters, Alkylated napthalenes (AN), Hexagonal boron nitride, Silicate esters, Glycerin, Polyvinyl alcohol (PVA), Cellulose ether, and the like. The example base fiber material is typically in granular, powder, or liquid form when in the example material hopper 30a.
The fiber formation system 30 is or may be any conventional system for forming fibers from the base pellets 40 of base fiber material. As examples, lubricity material may be combined (e.g., as an additive or blended with) with the base fiber material using systems for forming fibers including extrusion systems, dry spin systems, wet spin systems, gel spin systems, or other fiber production process.
The example fiber formation system 32 is an extrusion system capable of converting the base pellets 40 of base fiber material into elongate fibers. The example fiber formation system 32 employs a combination of heat and pressure to develop an elongate fiber structure from the base pellets 40 of base fiber material. In general, the heat and pressure are typically generated by mechanically processing the base pellets 40 and lubricity pellets 42 such as in a screw press (not shown). While a screw press will not completely melt the base pellets 40, the mechanical processing converts the granular or powderized base pellets 40 and lubricity pellets 42 into a flowable, plastic mass comprising both base fiber material and lubricity material that may be forced through an extrusion opening and pulled to obtain a continuous fiber structure or fiber structures 50 of desired dimensions. The fiber structure or fiber structures 50 so formed will thus comprise both the base fiber material and the lubricity material.
In any fiber formation system used to form the fiber structure(s) 50, the fiber structure(s) 50 so formed is (are) typically taken up on a spool or the like (not visible in
In turn, a plurality of the yarn structures 52 is combined using the rope formation system 34 to form a rope structure 54. The rope structure 54 may be formed by laying, braiding, or weaving the yarn structures 52 or rope sub-components formed of the yarn structures 52 to form a laid, braided, or woven rope structure.
When fabricating the yarn structures 52 or rope sub-components formed of the fiber structures 50, other types of yarns may be combined with the example fiber structures 50 such that the yarn structure 52 is a blended yarn structure. In addition or instead, the yarns structures 52 formed solely of the fiber structures 50 may be combined with other yarn structures comprising fibers for provide for purposes other than lubricity. In any such blended structure, the fiber structures 50 may provide lubricity to the yarn structure 52, and the other types of yarns in the yarn structure 52 may be provided for other purposes such as tensile strength. The rope structure 54 formed at least in part of the yarn structures 52 may thus be a blended rope comprising two or more different types of fibers for different purposes, where at least one of the types of fibers is formed by the example fiber structures 50 to provide lubricity to the rope structure 54.
As generally depicted in
The lubricity material may be selected such that, during use of the rope structure 54 comprising the yarn structures 52 and fibers 50, at least a portion of some of the lubricity portions 62 diffuses or otherwise migrates out the fibers 50. As an example, if a wax or oil is selected as the lubricity material, the lubricity portions 62 comprised of wax or oil may diffuse or otherwise migrate out of the body of the fibers 50 such that the lubricity material at least partly coats the fibers 50. The lubricity material will thus reduce the coefficient of friction of the fibers 50 over a wider portion of the fiber surface 64 of the fibers 50. Friction between the fibers 50 in a yarn 60 or rope structure 54 may create pressure and heat that will further encourage flowing or migrating of the lubricity material such that the lubricity material coats the fiber surface 64 of the fibers 50 and/or is otherwise arranged between adjacent fibers.
Alternatively, the lubricity material may be a solid or brittle material selected such that, during use of the rope structure 54 comprising the yarn structures 52 and fibers 50, at least a portion of some of the lubricity portions 62 may become separated from the fibers 50 in a granular or powder form. As an example, if the selected lubricity material is in the form of a brittle solid, the solid lubricity portions 62 may fall or wear off of the body of the fibers 50 such that a granular or powderized form of the lubricity material becomes entrapped between the fibers 50 forming the rope structure 54. The lubricity material in granular or powderized form will effectively reduce the coefficient of friction between the fibers 50 over a wider portion of the fiber surface 64 of the fibers 50 than that defined by the lubricity portions 62 alone. Further, friction between the fibers 50 in a yarn 60 or rope structure 54 will abrade the lubricity portions 62 on the fiber surface 64 such that the granular or powderized lubricity material is arranged between the surfaces 56 of adjacent fibers 50 and/or any other fiber forming the rope structure 54.
The presence of the lubricant material on the fiber surface 64 yields a fiber surface 64 with lubricity to reduce the wear and/or heat generation from the relative movement between the subcomponents of the rope. Further, the lubricity of the fiber surface 64 reduces friction and/or heat generation from the interaction of the rope structure 54 with any contacting surface that rope structure 54 touches. This reduction of the wear and/or heat is expected to prolong the rope's service life and performance.
II. Second Example Manufacturing System, Fiber, and Rope Structure
Referring now to
The material hopper 130a contains pellets, grains, or powder 140 (hereinafter referred to as “pellets 140”).
In the example pellets 140, the example lubricity material portion 144 takes the form of a coating of lubricity material formed on a core of base fiber material formed by the base fiber material portion 142. Each of the pellets will typically comprise more of the base fiber material than the lubricity material. The use of pellets 140 having a base fiber material portion 142 and an lubricity portion 144 ensures that the proportion of base fiber material to lubricity material in the material hopper 130a is consistent and that this proportion is maintained in as the pellets 140 are processed in the fiber formation system 130. The example pellets 140 are typically in granular or powder form when in the example material hopper 130a.
As generally described above, the present invention is of primary significance when applied to man-made or synthetic fibers, so the example base fiber material may be formed by at least one material selected from the group of materials: Nylon, Polyester, Polypropylene (PP), Olefin, Polyolefin, Polyethylene (PE), Polyacrylonitrile, Carbon, Aramid, PBO (Poly(p-phenylene-2,6-benzobisoxazole), LCP (Liquid Crystal Polymer), PIPD (Poly[2,6-diimidazo(4,5-b:4′,5′-e)pyridinylene-1,4(2,5-dihydroxy)phenylen]), PBI (Polybenziadazole), PEN (Polyethylene Naphthalate), Glass, Basalt, Metals and metal alloys, PVC (Polyvinyl Chloride), PVDC (Polyvinylidene Chloride), Polyurethane-polyurea, Polyvinyl Alcohol, PPS (Polyphylene Sulfide).
The lubricity material is a material that may be combined with the base fiber material such that a coefficient of friction of fibers formed of the base fiber material and the lubricity material is different from a coefficient of friction of fibers made from the base fiber material alone. Examples of materials that may be used as the example lubricity material include one or more of the following materials: Wax, Hydrogenated polyolefins, Silicones, Fluorocarbons, Graphite, Molybdenum Disulfide, Tungsten disulfide, Polyalpha-olefin (PAO), Synthetic esters, Polyalkylene glycols (PAG), Phosphate esters, Alkylated napthalenes (AN), Hexagonal boron nitride, Silicate esters, Glycerin, Polyvinyl alcohol (PVA), Cellulose ether, and the like.
The fiber formation system 130 is or may be any conventional system for forming fibers from the pellets 140. As examples, lubricity material may be combined (e.g., as an additive or blended with) with the base fiber material using systems for forming fibers including extrusion systems, dry spin systems, wet spin systems, gel spin systems, or other fiber production process.
The example fiber formation system 132 is an extrusion system capable of converting the pellets 140 into elongate fibers. The example fiber formation system 132 employs a combination of heat and pressure to develop an elongate fiber structure from the pellets 140. In general, the heat and pressure are typically generated by mechanically processing the pellets 140 such as in a screw press (not shown). While a screw press may not completely melt the base fiber material and lubricity material forming the pellets 140, the mechanical processing converts at least a portion of the granular or powderized pellets 140 into a flowable, plastic mass that may be forced through an extrusion opening and pulled to obtain a continuous second example fiber structure or fiber structures 150 of desired dimensions. The second example fiber(s) 150 so formed will be comprised of the base fiber material and the lubricity material.
In any fiber formation system used to form the second example fiber(s) 150, the fiber structure(s) 150 so formed is (are) typically taken up on a spool or the like (not visible in
In turn, a plurality of the second example yarn structures 152 (and possibly other yarn structures) is combined using the rope formation system 134 to form a second example rope structure 154. The second rope structure 154 may be formed by laying, braiding, or weaving at least the yarn structures 152 or rope sub-components formed of at least the yarn structures 152 to form a laid, braided, or woven rope structure.
When fabricating the yarn structures 152 or rope sub-components formed of the fiber structures 150, other types of yarns may be combined with the example fiber structures 150 such that the yarn structure 152 is a blended yarn structure. In addition or instead, the yarns structures 152 formed solely of the fiber structures 150 may be combined with other yarn structures comprising fibers for provide for purposes other than lubricity. In any such blended structure, the fiber structures 150 may provide lubricity to the yarn structure 152, and the other types of yarns in the yarn structure 152 may be provided for other purposes such as tensile strength. The rope structure 154 formed at least in part of the yarn structures 152 may thus be a blended rope comprising two or more different types of fibers for different purposes, where at least one of the types of fibers is formed by the example fiber structures 150 to provide lubricity to the rope structure 154.
As generally depicted in
The lubricity material may be selected such that, during use of the rope structure 154 comprising the yarn structures 152 and fibers 150, at least a portion of some of the lubricity portions 162 diffuses or otherwise migrates out the fibers 150. As an example, if a wax or oil is selected as the lubricity material, the lubricity portions 162 comprised of wax or oil may diffuse or otherwise migrate out of the body of the fibers 150 such that the lubricity material at least partly coats the fibers 150. The lubricity material will thus reduce the coefficient of friction of the fibers 150 over a wider portion of the fiber surface 164 of the fibers 150. Friction between the fibers 150 in a yarn 160 or rope structure 154 may create pressure and heat that will further encourage flowing or oozing of the lubricity material such that the lubricity material coats the fiber surface 164 of the fibers 150 and/or is otherwise arranged between adjacent fibers.
Alternatively, at least a portion of the lubricity material may be a solid or brittle material selected such that, during use of the rope structure 154 comprising the yarn structures 152 and fibers 150, at least a portion of some of the lubricity portions 162 may become separated from the fibers 150 in a granular or powder form. As an example, if the selected lubricity material is in the form of a brittle solid, the solid lubricity portions 162 may fall or wear off of the body of the fibers 150 such that a granular or powderized form of the lubricity material becomes entrapped between the fibers 150 forming the rope structure 154. The lubricity material in granular or powderized form will effectively reduce the coefficient of friction between the fibers 150 over a wider portion of the fiber surface 164 of the fibers 150 than that defined by the lubricity portions 162 alone. Further, friction between the fibers 150 in a yarn 152 or rope structure 154 will abrade the lubricity portions 162 on the fiber surface 164 such that the granular or powderized lubricity material is arranged between the surfaces 156 of adjacent fibers 150 and/or any other fiber forming the rope structure 154.
The presence of the lubricant lubricity material on the fiber surface 164 yields a fiber surface 164 with lubricity to reduce the wear and/or heat generation from the relative movement between the subcomponents of the rope. Further, the lubricity of the fiber surface 164 reduces friction and/or heat generation from the interaction of the rope structure 154 with any contacting surface that rope structure 154 touches. This reduction of the wear and/or heat is expected to prolong the rope's service life and performance.
III. Third Example Manufacturing System, Fiber, and Rope Structure
The first material hopper 230a contains pellets, grains, or powder 240 (hereinafter referred to as “base pellets 240”). The base pellets 240 comprise a base fiber material (indicated by right cross-hatching). The base pellets 240 are indicated by round or oval figures of equal size in
The second material hopper 232a contains pellets, grains, or powder 242 (hereinafter referred to as “lubricity pellets 240”). The lubricity pellets 242 comprise a lubricity material (indicated by left cross-hatching). The lubricity pellets 242 are indicated by round or oval figures of equal size in
As generally described above, the present invention is of primary significance when applied to fibers made of man-made or synthetic materials, so the example base fiber may be one or more of the following fibers: Nylon fiber, Polyester fiber, High Modulus Polypropylene (HMPP) fiber (e.g., Innegra), Olefin fiber, Polyolefin fiber; High Modulus Polyethylene (HMPE) fiber (e.g., Dnyeema, Spectra), Polyacrylonitrile fiber (e.g., Orlon), Carbon fiber, Aramid fiber (e.g., Twaron, Kevlar, Technora, Teijinconex), PBO (Poly(p-phenylene-2,6-benzobisoxazole) fiber (e.g., Zylon), LCP (Liquid Crystal Polymer) fiber (e.g., Vectran), PIPD (Poly[2,6-diimidazo(4,5-b:4′,5′-e)pyridinylene-1,4(2,5-dihydroxy)phenylen]) fiber (e.g., M5), PBI (Polybenziadazole) fiber, PEN (Polyethylene Naphthalate) fiber (e.g., Pentex), Glass fiber, Basalt fiber, Metallic fiber, PVC (Polyvinyl Chloride) fiber (e.g., Vinyon), PVDC (Polyvinylidene Chloride) fiber (e.g., Saran), Polyurethane-polyurea fiber (e.g., Spandex, Lycra), Polyvinyl Alcohol fiber (e.g., Vinalon), PPS (Polyphylene Sulfide) fiber (e.g. Ryton), and the like.
The lubricity material is a material that may be combined with the base fiber material such that a coefficient of friction of fibers formed of the base fiber material and the lubricity material is different from a coefficient of friction of fibers made from the base fiber material alone. Examples of materials that may be used as the example lubricity material include one or more of the following materials: Wax, Hydrogenated polyolefins, Silicones, Fluorocarbons, Graphite, Molybdenum Disulfide, Tungsten disulfide, Polyalpha-olefin (PAO), Synthetic esters, Polyalkylene glycols (PAG), Phosphate esters, Alkylated napthalenes (AN), Hexagonal boron nitride, Silicate esters, Glycerin, Polyvinyl alcohol (PVA), Cellulose ether, and the like.
The fiber formation system 230 is or may be any conventional system for forming fibers from the base pellets 240. As examples, the base fiber material may be manufactured using systems for forming fibers including extrusion systems, dry spin systems, wet spin systems, gel spin systems, or other fiber production process. In an implementation of the present invention such as the second example manufacturing system 220 depicted in
The example fiber formation system 230 is an extrusion system capable of converting the base pellets 240 into elongate fibers. The example fiber formation system 230 employs a combination of heat and pressure to develop an elongate fiber structure from the base pellets 240. In general, the heat and pressure are typically generated by mechanically processing the base pellets 240 such as in a screw press (not shown). While a screw press may not completely melt the base fiber material forming the base pellets 240, the mechanical processing converts at least a portion of the granular or powderized base pellets 240 into a flowable, plastic mass that may be forced through an extrusion opening and pulled to obtain a continuous fiber structure or fiber structures 250 of desired dimensions. As perhaps best shown in
At this point, the fiber structure(s) 250 may be taken up on a spool or bobbin and shipped to another facility for subsequent processing using the coating system 232, yarn formation system 234, and/or the rope formation system 234.
The example coating system 232 is any coating system capable of forming a coating or sheath 262 of the lubricity material on the core or base matrix portion 260 formed by the fiber structure(s) 250. In particular, the fiber formation system 230 employs an extrusion, pultrusion, or spray process capable of forming, from the lubricity pellets 242, a coating 262 over the core or base matrix portion 260 as shown in
In any fiber formation system used to form the fiber structure(s) 250, the fiber structure(s) 250 so formed is (are) typically taken up on a spool or the like (not visible in
At this point, the yarn structure(s) 250 may be shipped to another facility for subsequent processing using the rope formation system 234.
In turn, a plurality of the yarn structures 252 is combined using the rope formation system 236 to form a rope structure 254. The rope structure 254 may be formed by laying, braiding, or weaving the yarn structures 252 or rope sub-components formed of the yarn structures 252 to form a laid, braided, or woven rope structure.
When fabricating the yarn structures 252 or rope sub-components formed of the fiber structures 250, other types of yarns may be combined with the example fiber structures 250 such that the yarn structure 252 is a blended yarn structure. In addition or instead, the yarns structures 252 formed solely of the fiber structures 250 may be combined with other yarn structures comprising fibers for provide for purposes other than lubricity. In any such blended structure, the fiber structures 250 may provide lubricity to the yarn structure 252, and the other types of yarns in the yarn structure 252 may be provided for other purposes such as tensile strength. The rope structure 254 formed at least in part of the yarn structures 252 may thus be a blended rope comprising two or more different types of fibers for different purposes, where at least one of the types of fibers is formed by the example fiber structures 250 to provide lubricity to the rope structure 254.
As generally depicted in
The lubricity material may be selected such that, during use of the rope structure 254 comprising the yarn structures 252 and fibers 250, the lubricity material will reduce the coefficient of friction of the fibers 250 to reduce friction between the fibers 250 in the yarn 252 and/or rope structure 254.
The presence of the lubricant lubricity material on the fiber surface 264 yields a fiber surface 264 with lubricity to reduce the wear and/or heat generation from the relative movement between the subcomponents of the rope. Further, the lubricity of the fiber surface 264 reduces friction and/or heat generation from the interaction of the rope structure 254 with any contacting surface that rope structure 254 touches. This reduction of the wear and/or heat is expected to prolong the rope's service life and performance.
IV. Fourth Example Manufacturing System, Fiber, and Rope Structure
The first material hopper 330a contains pellets, grains, or powder 340 (hereinafter referred to as “base pellets 340”). The base pellets 340 comprise a base fiber material (indicated by right cross-hatching). The base pellets 340 are indicated by round or oval figures of equal size in
The second material hopper 332a contains additive liquid 342 (hereinafter referred to as “additive liquid 340”). The additive liquid 342 comprise a lubricity material (indicated by left cross-hatching).
As generally described above, the present invention is of primary significance when applied to man-made or synthetic fibers, so the example base fiber material will typically be formed of at least one synthetic material, including one or more of the following fibers: Nylon fiber, Polyester fiber, High Modulus Polypropylene (HMPP) fiber (e.g., Innegra), Olefin fiber, Polyolefin fiber, High Modulus Polyethylene (HMPE) fiber (e.g., Dnyeema, Spectra), Polyacrylonitrile fiber (e.g., Orlon), Carbon fiber, Aramid fiber (e.g., Twaron, Kevlar, Technora, Teijinconex), PBO (Poly(p-phenylene-2,6-benzobisoxazole) fiber (e.g., Zylon), LCP (Liquid Crystal Polymer) fiber (e.g., Vectran), PIPD (Poly[2,6-diimidazo (4,5-b:4′,5′-e)pyridinylene-1,4(2,5-dihydroxy)phenylen]) fiber (e.g., M5), PBI (Polybenziadazole) fiber, PEN (Polyethylene Naphthalate) fiber (e.g., Pentex), Glass fiber, Basalt fiber, Metallic fiber, PVC (Polyvinyl Chloride) fiber (e.g., Vinyon), PVDC (Polyvinylidene Chloride) fiber (e.g., Saran), Polyurethane-polyurea fiber (e.g., Spandex, Lycra), Polyvinyl Alcohol fiber (e.g., Vinalon), PPS (Polyphylene Sulfide) fiber (e.g. Ryton), and the like.
The lubricity material is a material that may be combined with the base fiber material such that a coefficient of friction of fibers formed of the base fiber material and the lubricity material is different from a coefficient of friction of fibers made from the base fiber material alone. Examples of materials that may be used as the example lubricity material include one or more of the following materials: Wax, Hydrogenated polyolefins, Silicones, Fluorocarbons, Graphite, Molybdenum Disulfide, Tungsten disulfide, Polyalpha-olefin (PAO), Synthetic esters, Polyalkylene glycols (PAG), Phosphate esters, Alkylated napthalenes (AN), Hexagonal boron nitride, Silicate esters, Glycerin, Polyvinyl alcohol (PVA), Cellulose ether, and the like.
These example lubricity materials may be configured in liquid form for storage in the second example material hopper 332a and application by the coating system 332 or may be suspended by or dissolved within a carrier liquid. The carrier liquid may evaporate to leave the lubricity material and/or a binder, or the carrier liquid may contain the lubricity material and a chemically curable binder.
The fiber formation system 330 is or may be any conventional system for forming fibers from the base pellets 340. As examples, lubricity material the base fiber material may be manufactured using systems for forming fibers including extrusion systems, dry spin systems, wet spin systems, gel spin systems, or other fiber production process.
In an implementation of the present invention such as the third example manufacturing system 320 depicted in
The example fiber formation system 330 is an extrusion system capable of converting the base pellets 340 into elongate fibers. The example fiber formation system 330 employs a combination of heat and pressure to develop an elongate fiber structure from the base pellets 340. In general, the heat and pressure are typically generated by mechanically processing the base pellets 340 such as in a screw press (not shown). While a screw press may not completely melt the base fiber material forming the base pellets 340, the mechanical processing converts at least a portion of the granular or powderized base pellets 340 into a flowable, plastic mass that may be forced through an extrusion opening and pulled to obtain a continuous fiber structure or fiber structures 350 of desired dimensions. As perhaps best shown in
At this point, the fiber structure(s) 350 may be taken up on a spool or bobbin and shipped to another facility for subsequent processing using the coating system 332, yarn formation system 334, and/or the rope formation system 334. As one example, a fiber manufacturer may make the fiber structure(s) 350, and these fiber structures 350 may be shipped to a rope manufacturer for coating using the coating system 332.
The example coating system 332 is any coating system capable of forming a coating or sheath 362 of the lubricity material on the core or base matrix portion 360 formed by the fiber structure(s) 350 as shown in
In any fiber formation system used to form the fiber structure(s) 350, the fiber structure(s) 350 so formed is (are) typically taken up on a spool or the like (not visible in
The fiber structure or fiber structures 350 are subsequently combined to form one or more yarn structures 352 comprising a plurality of the fibers 350 using the yarn formation system 334. In turn, a plurality of the yarn structures 352 is combined using the rope formation system 336 to form a rope structure 354. The rope structure 354 may be formed by laying, braiding, or weaving the yarn structures 352 or rope sub-components formed of the yarn structures 352 to form a laid, braided, or woven rope structure.
When fabricating the yarn structures 352 or rope sub-components formed of the fiber structures 350, other types of yarns may be combined with the example fiber structures 350 such that the yarn structure 352 is a blended yarn structure. In addition or instead, the yarns structures 352 formed solely of the fiber structures 350 may be combined with other yarn structures comprising fibers for provide for purposes other than lubricity. In any such blended structure, the fiber structures 350 may provide lubricity to the yarn structure 352, and the other types of yarns in the yarn structure 352 may be provided for other purposes such as tensile strength. The rope structure 354 formed at least in part of the yarn structures 352 may thus be a blended rope comprising two or more different types of fibers for different purposes, where at least one of the types of fibers is formed by the example fiber structures 350 to provide lubricity to the rope structure 354.
As generally depicted in
The lubricity material may be selected such that, during use of the rope structure 354 comprising the yarn structures 352 and fibers 350, the lubricity material will reduce the coefficient of friction of the fibers 350 to reduce friction between the fibers 350 in the yarn 352 and/or rope structure 354.
The presence of the lubricant lubricity material on the fiber surface 364 yields a fiber surface 364 with lubricity to reduce the wear and/or heat generation from the relative movement between the subcomponents of the rope. Further, the lubricity of the fiber surface 364 reduces friction and/or heat generation from the interaction of the rope structure 354 with any contacting surface that rope structure 354 touches. This reduction of the wear and/or heat is expected to prolong the rope's service life and performance.
