EP1942224A1 - Cable with low structural elongation - Google Patents
Cable with low structural elongation Download PDFInfo
- Publication number
- EP1942224A1 EP1942224A1 EP07000237A EP07000237A EP1942224A1 EP 1942224 A1 EP1942224 A1 EP 1942224A1 EP 07000237 A EP07000237 A EP 07000237A EP 07000237 A EP07000237 A EP 07000237A EP 1942224 A1 EP1942224 A1 EP 1942224A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- cable
- steel
- elongation
- steel cord
- present
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
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Classifications
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B1/00—Constructional features of ropes or cables
- D07B1/06—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B1/00—Constructional features of ropes or cables
- D07B1/16—Ropes or cables with an enveloping sheathing or inlays of rubber or plastics
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B1/00—Constructional features of ropes or cables
- D07B1/06—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core
- D07B1/0673—Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core having a rope configuration
-
- 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
- D07B2201/2075—Fillers
- D07B2201/2079—Fillers characterised by the kind or amount of filling
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2401/00—Aspects related to the problem to be solved or advantage
- D07B2401/20—Aspects related to the problem to be solved or advantage related to ropes or cables
- D07B2401/2005—Elongation or elasticity
- D07B2401/201—Elongation or elasticity regarding structural elongation
-
- D—TEXTILES; PAPER
- D07—ROPES; CABLES OTHER THAN ELECTRIC
- D07B—ROPES OR CABLES IN GENERAL
- D07B2501/00—Application field
- D07B2501/20—Application field related to ropes or cables
- D07B2501/2084—Mechanical controls, e.g. door lashes
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
- Y10T428/2913—Rod, strand, filament or fiber
- Y10T428/2933—Coated or with bond, impregnation or core
- Y10T428/294—Coated or with bond, impregnation or core including metal or compound thereof [excluding glass, ceramic and asbestos]
Definitions
- the present invention relates to a cable. More specifically present invention relates to a cable with limited elongation.
- Cables and more specifically control cables are widely used to transmit movement, such as cable for window elevator system, cables used to open and close braks of scooters, bicycles and other vehicles. In these and many other applications, a limited elongation of the cable is required.
- Cables are also widely used as tension member to reinforce polymer materials, such as steel cords to reinforce radial tires, cables to reinforce transmission belts, timing belts or flat hoisting belts. In these applications, a limited elongation of the cable is also required.
- the tensile curve of a cable of prior art takes the form of "hockey stick" curve as illustrated by FIGURE1 .
- the elongation of the cable is large while the tension is low, and the curve is relative flat.
- the elongation of cable is almost linear to the tension of the cable as illustrated by line 120 in FIGURE1 .
- the elongation of the cable increases steadily with the increase of the tension.
- the increase of the elongation of the cable is proportional to the increase of the tension of the cable, i.e.
- ⁇ ⁇ ⁇ /E
- ⁇ the increase of the elongation of the cable
- ⁇ the increase of the tension of the cable
- E the module of the cable.
- This is called the elastic elongation.
- structural elongation ⁇ 0 of a cable is unstable and unpredictable, because there are a lot of facts, such as the structure of the cable, the voids between the filaments of the cable, and the pretension of the filaments when cabling the cable, that determine the structural elongation of a cable. Therefore, the unstable and unpredictable behavior of structural elongation of a cable causes problems to predict the total elongation of the cable under tension and more scrap during the start-up of machine producing for instance the high-precision timing belts. Hence, further reducing or almost eliminating the structural elongation ⁇ 0 can improve the predictability of the tension-elongation curve of the cable and facilitate the manufacturing process.
- WO03044267A1 disclosed a cable with limited elongation, less than 0.05% at a permanent force of 50N, after being subjected to a force of 450N. This improvement is achieved by a cord comprising a steel cord and a polymer material.
- the low elongation is highly related to the penetration of polymer material into the steel cord, but there are limits on the penetration rate and the pressure for the extrusion process.
- WO2005043003A1 disclosed a fine steel cord with low structural elongation.
- the low structural elongation is achieved by using a special cabling process.
- This special cabling process not only decreases the productivity of the cabling process but also ask for a lengthy fine tune procedure to set the tension of the filaments or strands.
- a cable comprising a steel cord and a polymer material.
- the steel filaments of the steel cord are coated with an adhesive before the penetration of the polymer material.
- the cable has a structural elongation less than 0.025%.
- the E module of the cable increases by more than 4% compared with the E module of the bare steel cord.
- the cable as subject of the invention comprises a steel cord, which on its turn comprises several steel filaments.
- the tensile strength of the steel filaments for the steel cord are preferably more than 1700N/mm 2 , or more than 2200N/mm 2 or even more than 2600N/mm 2 , most preferably more than 3000N/mm 2 or even more than 4000N/mm 2 .
- the diameter of the filaments is less than 400 ⁇ m, preferably less than 210 ⁇ m, most preferably less than 110 ⁇ m.
- All filaments may have an identical diameter. Possible the diameter of the filaments may differ from each other. Preferably, the diameter of the filaments providing an inner strand of the cable is larger than the diameter of the filaments used to provide the outer strands or layer of filaments to the cable, which improves the penetration of the polymer material into the void spaces of the cable.
- Steel cords have an inner layer or core, which is preferably a strand of several steel filaments. Around such core, at least one layer of additional steel elements is provided.
- the steel elements of the additional layer can either be steel filaments or steel strands, on its turn comprising steel filaments.
- Various steel cord construction may be used.
- the steel composition of the steel cord is preferably a plain carbon steel composition, i.e. it generally comprises a minimum carbon content of 0.40% (e.g. at least 0.60% or at least 0.80%, with a maximum of 1.1 %), a manganese content ranging from 0.10 to 0.90% and a silicon content ranging from 0.10 to 0.90%; the sulfur and phosphorous contents are each preferably kept below 0.03%; additional micro-alloying elements such as chromium (up to 0.2 to 0.4%), boron, cobalt, nickel, vanadium...may be added to the composition; stainless steel compositions are, however, not excluded.
- the production of the steel filaments and the steel cords is performed according to known prior art techniques of wet drawing followed by cabling or bunching.
- the steel cord is then coated with an adhesive selected from organo functional silanes, organo functional titanates and organo functional zirconates which are known in the art for the improvement of adhesion between the steel cord and polymer material.
- organo functional silanes are selected from the compounds of the following formula: Y-(CH 2 ) N -SiX 3
- the polymer material used for the present invention can be any elastomeric material that can conveniently be applied to the steel cord with sufficient adhesion. More preferably a thermoplastic elastomer (TPE) can be used.
- TPE thermoplastic elastomer
- Non-delimiting examples are polystyrene/elastomer block copolymers, polyurethane (PU) or polyurethane copolymers, polyamide/elastomer block copolymers, thermoplastic vulcanizates.
- thermoplastic polyurethane is used. Homopolymers of ester, ether or carbonate polyurethane may be used, as well as copolymers or polymer blends.
- the polymer material has a shore hardness varying between 30A and 90D.
- the polymer penetration rate of a cable as subject matter of the present invention is more than 70%, and preferably more than 90%.
- the steel cord used to provide a cable as subject matter of the present invention comprises several steel filaments being transformed into a steel cord, using a steel cord construction. Due to the steel cord construction, void spaces are provided between the steel filaments of the steel elements of the cord. Also void spaces are provided between the steel elements. "Void space” as used hereafter is to be understood as all area of a radial cross-section of the cord, located inwards of the imaginary circle which encircles a radial cross section of the steel cord which area is not occupied by steel. Therefore, the polymer penetration rate of a cable of present invention is defined as the ratio in percentage of the void space filled by polymer to the void space which is not occupied by steel.
- the thickness of the polymer coating of the present invention is less than 100 ⁇ m, and preferably less than 10 ⁇ m.
- the optical diameter of the steel cord used to provide a cable as subject matter of the present invention is the diameter of the smallest imaginary circle, which encircles a radial cross section of the steel cord.
- the optical diameter of the cable of the present invention is the diameter of the smallest imaginary circle, which encircles a radial cross section of the cable. Therefore, the thickness of the polymer is defined as the half of the difference of the optical diameter between the cable and the steel cord.
- FIGURE 1 there is shown a tensile curve 110 of a cable of prior art, and line 120 represents the E module of the cable. Line 120 extends and intersects with the abscissa axis at the intersection point ⁇ 0, representing the structural elongation at low tensile stresses of the cable.
- FIGURE 2 there is a cross section view of a cable incorporating the present invention.
- the cable 211 comprises a steel cord 212, which on its turn comprises several steel filaments 213.
- the present embodiment shows a steel cord with "7x7xd" structure having seven strands 219, each strand having seven steel filaments 213 of diameter of d mm.
- the steel cord has an optical cord diameter 214.
- the steel cord is coated with a polymer material 215, so providing a cable 211 as subject matter of the present invention with an optical cable diameter 216.
- the thickness 217 of the polymer coating is half of the difference between optical cord diameter and optical cable diameter.
- the void space 218 between the different steel filaments 213 is substantially filled with polymer material 215.
- FIGURE 3 there is shown a tensile curve 310 of a cable incorporating the present invention, and line 320 represents the E module of the cable.
- Line 320 extends and intersects with the abscissa axis at the intersection point ⁇ 0, representing the structural elongation at low tensile stresses of the cable.
- the use of an adhesive on the surface of steel filaments before the application of polymer material further improves the anchorage of steel filaments inside polymer material.
- the steel filaments of the steel cord are constrained from slipping and turning even there are some void spaces unfilled by polymer material, which further limits the structural elongation of the cable.
- the improved anchorage of steel filaments inside polymer material also improves the E module of the cable because there is no slippage or peeling between steel filaments and polymer material.
- a further improvement to the present invention is characterized by the thickness of the polymer coating of the cable.
- a cable with polymer coating of 10 ⁇ m only marginally increases the diameter of the cable, which is especially valuable for the cable used as tension member to reinforce synchronous belt. Because the synchronous belt is molded in a semi-open mold where the polymer material is poured into the mold or extruded with a low pressure, the polymer material inside the mold has limited ability to flow between the tension members and to form the final requested shape (toothed, flat, even, ). Therefore, a fine cable with less than 10 ⁇ m polymer coating will leave more space for the polymer material to flow inside the mold and to form a flat and even belt.
- the metal nipple clamps directly to the steel cord because of the deformation of thin coating of polymer material.
- This application secures the connection between cable and nipple and eliminates the weak point for the system.
- the coating thickness is less than 10 ⁇ m or even 0 ⁇ m, from the outside the cable is virtually the same as a bare cable with the same friction and wear properties. This might be of a big advantage when one would like to substitute a bare cable by such a products in a cable system since there is no need to change the guiding part, cable tubes, etc.
- Another improvement with present invention is to use the cable as the subject matter of present invention to build a multi-strand rope for hoisting applications such as elevator ropes.
- the elevator industry is looking for ropes with limited elongation. Since the strands have limited elongation, the rope will have a limited elongation either. Hence, elevator ropes using present invention meet this requirement.
- the elevator industry is looking for ropes that are capable of running on small sheave diameters.
- the standard elevator uses ropes that respect the generally accepted sheave diameter "d" over rope diameter "D” ratio of 40. When traditional all steel ropes are used in conditions where the d/D ratio is lower than 40, the fatigue life of ropes drops significantly.
Abstract
A cable (211) is provided comprising a steel cord (212) and a polymer material (215). The steel filaments (213) of the steel cord (212) are coated with an adhesive before the penetration of the polymer material (215). The cable (211) has a structural elongation less than 0.025% and an E module 4% greater than the E module of the steel cord (212). These two improvements further decrease the total elongation of the cable at certain load.
Description
- The present invention relates to a cable. More specifically present invention relates to a cable with limited elongation.
- Cables and more specifically control cables are widely used to transmit movement, such as cable for window elevator system, cables used to open and close braks of scooters, bicycles and other vehicles. In these and many other applications, a limited elongation of the cable is required.
- Cables are also widely used as tension member to reinforce polymer materials, such as steel cords to reinforce radial tires, cables to reinforce transmission belts, timing belts or flat hoisting belts. In these applications, a limited elongation of the cable is also required.
- Generally, the tensile curve of a cable of prior art takes the form of "hockey stick" curve as illustrated by
FIGURE1 . At the initial elongation period, the elongation of the cable is large while the tension is low, and the curve is relative flat. At the terminal elongation period, the elongation of cable is almost linear to the tension of the cable as illustrated byline 120 inFIGURE1 . The elongation of the cable increases steadily with the increase of the tension. At this stage, the increase of the elongation of the cable is proportional to the increase of the tension of the cable, i.e. Δε=Δδ/E, wherein Δε is the increase of the elongation of the cable, Δδ the increase of the tension of the cable, and E the module of the cable. This is called the elastic elongation. If we extendline 120 to intersect with the abscissa axis, the intersection point ε0 represents the structural elongation at low tensile stresses of the cable. Therefore, the elongation of a cable at certain tensile stress can be expressed by ε=ε0+δ/E. From this equation, we can see that the total elongation of a cable at certain tensile stress comprises two portions of elongations: structural elongation and the elastic elongation. Therefore, there are two approaches to get a cable with limited elongation. One way is to decrease the structural elongation of the cable, and the other way to increase the E module of the cable, because the elongation under tensile decreases when the E module of the cable increases. - Besides, structural elongation ε0 of a cable is unstable and unpredictable, because there are a lot of facts, such as the structure of the cable, the voids between the filaments of the cable, and the pretension of the filaments when cabling the cable, that determine the structural elongation of a cable. Therefore, the unstable and unpredictable behavior of structural elongation of a cable causes problems to predict the total elongation of the cable under tension and more scrap during the start-up of machine producing for instance the high-precision timing belts. Hence, further reducing or almost eliminating the structural elongation ε0 can improve the predictability of the tension-elongation curve of the cable and facilitate the manufacturing process.
-
WO03044267A1 -
WO2005043003A1 disclosed a fine steel cord with low structural elongation. The low structural elongation is achieved by using a special cabling process. This special cabling process not only decreases the productivity of the cabling process but also ask for a lengthy fine tune procedure to set the tension of the filaments or strands. - It is an objective of the present invention to eliminate the drawback of the prior art. It is also an objective of the present invention to further limit the elongation of a cable without complicating the manufacturing process of the cabling process.
- According to the present invention, a cable is provided comprising a steel cord and a polymer material. The steel filaments of the steel cord are coated with an adhesive before the penetration of the polymer material. The cable has a structural elongation less than 0.025%. Besides, the E module of the cable increases by more than 4% compared with the E module of the bare steel cord. These two improvements further decrease the total elongation of the cable at certain load.
- The cable as subject of the invention comprises a steel cord, which on its turn comprises several steel filaments.
- The tensile strength of the steel filaments for the steel cord are preferably more than 1700N/mm2, or more than 2200N/mm2 or even more than 2600N/mm2, most preferably more than 3000N/mm2 or even more than 4000N/mm2. The diameter of the filaments is less than 400µm, preferably less than 210µm, most preferably less than 110µm.
- All filaments may have an identical diameter. Possible the diameter of the filaments may differ from each other. Preferably, the diameter of the filaments providing an inner strand of the cable is larger than the diameter of the filaments used to provide the outer strands or layer of filaments to the cable, which improves the penetration of the polymer material into the void spaces of the cable.
- Steel cords have an inner layer or core, which is preferably a strand of several steel filaments. Around such core, at least one layer of additional steel elements is provided. The steel elements of the additional layer can either be steel filaments or steel strands, on its turn comprising steel filaments. Various steel cord construction may be used.
- Examples here are:
- Multi-strand steel cord e.g. of the m x n type, i.e. steel cords, comprising m strands with each n steel filaments, such as 4x7x0.10, 7x7x0.18, 8x7x0.18 or 3x3x0.18; the last number is the diameter of the steel filament expressed in mm;
- Multi-strand steel cord, comprising a core strand of c metal filaments, and m strands of n steel filaments, surrounding the core strand. These steel cords are hereafter referred to as c+mxn type cords, such as 19+9x7 or 19+8x7 cords;
- Warrington-type steel cords;
- Compact cords, e.g. of the 1xn type, i.e. steel cords comprising n steel filaments, n being greater than 8, twisted in only one direction with one single step to a compact cross-section, such as 1x9x0.18; the last number is the diameter of the filament expressed in mm;
- Layered steel cord e.g. of the c+m(+n) type, i.e. steel cord with a core of c filaments, surrounded by a layer of m filaments, and possibly also surrounded by another layer of n filaments, such as 2+4x0.18; the last number is the diameter of the filaments expressed in mm.
- The steel composition of the steel cord is preferably a plain carbon steel composition, i.e. it generally comprises a minimum carbon content of 0.40% (e.g. at least 0.60% or at least 0.80%, with a maximum of 1.1 %), a manganese content ranging from 0.10 to 0.90% and a silicon content ranging from 0.10 to 0.90%; the sulfur and phosphorous contents are each preferably kept below 0.03%; additional micro-alloying elements such as chromium (up to 0.2 to 0.4%), boron, cobalt, nickel, vanadium...may be added to the composition; stainless steel compositions are, however, not excluded. The production of the steel filaments and the steel cords is performed according to known prior art techniques of wet drawing followed by cabling or bunching.
- After an optional cleaning operation, the steel cord is then coated with an adhesive selected from organo functional silanes, organo functional titanates and organo functional zirconates which are known in the art for the improvement of adhesion between the steel cord and polymer material. Preferably, but not exclusively, the organo functional silanes are selected from the compounds of the following formula:
Y-(CH2)N-SiX3
- Wherein:
- Y represents an organo functional group selected from -NH2, CH2=CH-, CH2=C(CH3)COO-, 2,3-epoxypropoxy, HS- and, Cl-
- X represents a silicon functional group selected from -OR, -OC(=O)R', - Cl wherein R and R' are independently selected from C1 to C4 alkyl, preferably -CH3, and -C2H5; and
- n is an integer between 0 and 10, preferably from 0 to 3.
- Besides the organo functional silanes mentioned above, there are other steel PU adhesives commercially available on the market. They are sold under the name Chemosil (made by the German company Henkel) and Chemlock (made by Lord Corporation).
- The polymer material used for the present invention can be any elastomeric material that can conveniently be applied to the steel cord with sufficient adhesion. More preferably a thermoplastic elastomer (TPE) can be used. Non-delimiting examples are polystyrene/elastomer block copolymers, polyurethane (PU) or polyurethane copolymers, polyamide/elastomer block copolymers, thermoplastic vulcanizates. Preferably thermoplastic polyurethane is used. Homopolymers of ester, ether or carbonate polyurethane may be used, as well as copolymers or polymer blends. Preferably, the polymer material has a shore hardness varying between 30A and 90D.
- The polymer penetration rate of a cable as subject matter of the present invention is more than 70%, and preferably more than 90%. The steel cord used to provide a cable as subject matter of the present invention comprises several steel filaments being transformed into a steel cord, using a steel cord construction. Due to the steel cord construction, void spaces are provided between the steel filaments of the steel elements of the cord. Also void spaces are provided between the steel elements. "Void space" as used hereafter is to be understood as all area of a radial cross-section of the cord, located inwards of the imaginary circle which encircles a radial cross section of the steel cord which area is not occupied by steel. Therefore, the polymer penetration rate of a cable of present invention is defined as the ratio in percentage of the void space filled by polymer to the void space which is not occupied by steel.
- The thickness of the polymer coating of the present invention is less than 100µm, and preferably less than 10µm. The optical diameter of the steel cord used to provide a cable as subject matter of the present invention is the diameter of the smallest imaginary circle, which encircles a radial cross section of the steel cord. The optical diameter of the cable of the present invention is the diameter of the smallest imaginary circle, which encircles a radial cross section of the cable. Therefore, the thickness of the polymer is defined as the half of the difference of the optical diameter between the cable and the steel cord.
- The invention will now be described into more detail with reference to the accompanying drawings wherein
-
FIGURE 1 is a tensile curve of a cable of prior arts; -
FIGURE 2 is a cross-sectional view of a cable incorporating the present invention; -
FIGURE 3 is a tensile curve of a cable incorporating the present invention. -
Item 110 is the tensile curve of a cable of prior arts; -
Item 120 is a line representing the E module of a cable of prior arts; -
Item 211 is a cable incorporating the present invention; -
Item 212 is a steel cord for the cable incorporating the present invention; -
Item 213 is a steel filament for the cable incorporating the present invention; -
Item 214 is the optical diameter of the steel cord for the cable incorporating the present invention; -
Item 215 is a polymer material used for the cable incorporating the present invention; -
Item 216 is the optical diameter of the cable incorporating the present invention; -
Item 217 is the thickness of the polymer coating of the cable incorporating the present invention; -
Item 218 is the void space in the cable incorporating the present invention; -
Item 219 is the steel strand for the cable incorporating the present invention; -
Item 310 is the tensile curve of a cable incorporating the present invention; -
Item 320 is a line representing the E module of a cable incorporating the present invention; - ε0 is the structural elongation of a cable;
- F(N) is the force in Newton on the test specimen;
- E(%) is the elongation in percentage of the test specimen.
- In
FIGURE 1 , there is shown atensile curve 110 of a cable of prior art, andline 120 represents the E module of the cable.Line 120 extends and intersects with the abscissa axis at the intersection point ε0, representing the structural elongation at low tensile stresses of the cable. - As shown in
FIGURE 2 , there is a cross section view of a cable incorporating the present invention. Thecable 211 comprises asteel cord 212, which on its turn comprisesseveral steel filaments 213. The present embodiment shows a steel cord with "7x7xd" structure having sevenstrands 219, each strand having sevensteel filaments 213 of diameter of d mm. The steel cord has anoptical cord diameter 214. The steel cord is coated with apolymer material 215, so providing acable 211 as subject matter of the present invention with anoptical cable diameter 216. Thethickness 217 of the polymer coating is half of the difference between optical cord diameter and optical cable diameter. As shown inFIGURE 2 , preferably thevoid space 218 between thedifferent steel filaments 213 is substantially filled withpolymer material 215. - In
FIGURE 3 , there is shown atensile curve 310 of a cable incorporating the present invention, andline 320 represents the E module of the cable.Line 320 extends and intersects with the abscissa axis at the intersection point ε0, representing the structural elongation at low tensile stresses of the cable. - In the following tables, there are shown comparison tests between the cable with prior art and the cable incorporating the present invention. The test is conducted according to ISO test method ISO RA-30-203 on Zwick-Z020 test machine. When one test is finished, the test machine can automatically provide the following test results and the tensile curve of the test specimen.
- Prior art: 1x3+5x7x0.15 steel cord;
Present invention: 1x3+5x7x0.15 steel cord with adhesive treatment and PU coatinq.Structural elongation ε0 E module N/mm2 Elongation at 50N Prior art 0.082% 168072 0.125% Present invention 0.021 % 184293 0.060% Improvements against prior art - 74% +9.6% - 52% FIGURE 1 and3 also illustrate this improvement. - Comparison test 2:
- Prior art 1: 7x3x0.15 steel cord;
- Prior art 2: 7x3x0.15 steel cord with PU coating;
- Compared with prior art, the use of an adhesive on the surface of steel filaments before the application of polymer material further improves the anchorage of steel filaments inside polymer material. The steel filaments of the steel cord are constrained from slipping and turning even there are some void spaces unfilled by polymer material, which further limits the structural elongation of the cable. Besides, the improved anchorage of steel filaments inside polymer material also improves the E module of the cable because there is no slippage or peeling between steel filaments and polymer material.
- A further improvement to the present invention is characterized by the thickness of the polymer coating of the cable. A cable with polymer coating of 10µm only marginally increases the diameter of the cable, which is especially valuable for the cable used as tension member to reinforce synchronous belt. Because the synchronous belt is molded in a semi-open mold where the polymer material is poured into the mold or extruded with a low pressure, the polymer material inside the mold has limited ability to flow between the tension members and to form the final requested shape (toothed, flat, even, ...). Therefore, a fine cable with less than 10µm polymer coating will leave more space for the polymer material to flow inside the mold and to form a flat and even belt.
- Another application with this fine cable with less than 10µm polymer coating is for window elevator system. Because the cable used for window elevator system needs to be clamped by metal nipples at the end of the cable to connect other parts, cables with thick polymer coating can not guarantee a secured connection between the end of the cable and the nipple. The nipple clamps on the polymer coating and the polymer coating transfers the tension to the steel cord inside. Since the tensile strength of the polymer material is quite low compared with that of the steel cord, the connection between cable and nipple breaks at low load, and the load transmission ability of the cable is undermined due to this weak point. When a cable with less than 10µm polymer coating is used in a window elevator system, the metal nipple clamps directly to the steel cord because of the deformation of thin coating of polymer material. This application secures the connection between cable and nipple and eliminates the weak point for the system. Besides, when the coating thickness is less than 10µm or even 0µm, from the outside the cable is virtually the same as a bare cable with the same friction and wear properties. This might be of a big advantage when one would like to substitute a bare cable by such a products in a cable system since there is no need to change the guiding part, cable tubes, etc.
- Another improvement with present invention is to use the cable as the subject matter of present invention to build a multi-strand rope for hoisting applications such as elevator ropes. Firstly, the elevator industry is looking for ropes with limited elongation. Since the strands have limited elongation, the rope will have a limited elongation either. Hence, elevator ropes using present invention meet this requirement. Secondly, the elevator industry is looking for ropes that are capable of running on small sheave diameters. The standard elevator uses ropes that respect the generally accepted sheave diameter "d" over rope diameter "D" ratio of 40. When traditional all steel ropes are used in conditions where the d/D ratio is lower than 40, the fatigue life of ropes drops significantly. One of the failure causes of the ropes under these conditions is excessive inter-strand and inter-wire fretting. Although a polymer coating on the rope can reduce the fretting and improve the fatigue life of the rope, a thick polymer coating is needed to secure an endurable polymer sheath and the thick coating increase the diameter of the rope. Present invention solves this dilemma. On one hand, steel strands are coated with polymer to reduce the fretting. On the other hand, adhesive treatment improves the connection between steel and polymer and makes a thin coating possible. Therefore, ropes made of cables of present invention are suitable for hoisting applications.
Structural elongation ε0 | E module N/mm2 | Elongation at 50N | |
Prior art 1 | 0.044% | 176357 | 0.119% |
Prior art 2 | 0.031% | 180437 | 0.105% |
Present invention | 0.004% | 182778 | 0.077% |
Improvements against prior art 1 | - 91 % | + 4% | - 35% |
Claims (9)
- A cable comprising a steel cord and a polymer material, characterized in that the structural elongation of said cable is less than 0.025%.
- A cable as claimed in claim 1, characterized in that the E module of said cable is 4% greater than the E module of said steel cord.
- A cable as claimed in any one of claim 1 and 2, characterized in that the polymer filling rate is more than 70%.
- A cable as claimed in claim 3, characterized in that the polymer filling rate is more than 90%.
- A cable as claimed in any one of claim 1 to 4, characterized in that the thickness of the polymer coating is less than 100µm.
- A cable as claimed in claim 5, characterized in that the thickness of polymer coating is less than 10µm.
- A cable as claimed in any one of claim 1 to 6, characterized in that said polymer material is a thermoplastic polymer.
- A cable as claimed in claim 7, characterized in that said thermoplastic polymer is polyurethane.
- A rope comprising at least one cable as claimed in claim 1 to 8.
Priority Applications (10)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP07000237A EP1942224A1 (en) | 2007-01-08 | 2007-01-08 | Cable with low structural elongation |
PL08701235T PL2104764T3 (en) | 2007-01-08 | 2008-01-04 | Cable with low structural elongation |
KR1020097014218A KR101444488B1 (en) | 2007-01-08 | 2008-01-04 | Cable with low structural elongation |
PT08701235T PT2104764E (en) | 2007-01-08 | 2008-01-04 | Cable with low structural elongation |
US12/522,332 US20100009184A1 (en) | 2007-01-08 | 2008-01-04 | Cable with low structural elongation |
ES08701235T ES2387220T3 (en) | 2007-01-08 | 2008-01-04 | Cable with low structural elongation |
EP08701235A EP2104764B1 (en) | 2007-01-08 | 2008-01-04 | Cable with low structural elongation |
PCT/EP2008/050053 WO2008084010A1 (en) | 2007-01-08 | 2008-01-04 | Cable with low structural elongation |
JP2009545160A JP5289329B2 (en) | 2007-01-08 | 2008-01-04 | Cable with low structural elongation |
CN2008800018760A CN101578415B (en) | 2007-01-08 | 2008-01-04 | Cable with low structural elongation |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP07000237A EP1942224A1 (en) | 2007-01-08 | 2007-01-08 | Cable with low structural elongation |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1942224A1 true EP1942224A1 (en) | 2008-07-09 |
Family
ID=38024110
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP07000237A Withdrawn EP1942224A1 (en) | 2007-01-08 | 2007-01-08 | Cable with low structural elongation |
EP08701235A Active EP2104764B1 (en) | 2007-01-08 | 2008-01-04 | Cable with low structural elongation |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP08701235A Active EP2104764B1 (en) | 2007-01-08 | 2008-01-04 | Cable with low structural elongation |
Country Status (9)
Country | Link |
---|---|
US (1) | US20100009184A1 (en) |
EP (2) | EP1942224A1 (en) |
JP (1) | JP5289329B2 (en) |
KR (1) | KR101444488B1 (en) |
CN (1) | CN101578415B (en) |
ES (1) | ES2387220T3 (en) |
PL (1) | PL2104764T3 (en) |
PT (1) | PT2104764E (en) |
WO (1) | WO2008084010A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010052075A1 (en) * | 2008-11-10 | 2010-05-14 | Contitech Antriebssysteme Gmbh | Traction mechanism, tractive drive comprising said traction mechanism, and lift installation |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2585632A4 (en) * | 2010-07-23 | 2015-04-15 | Schlumberger Technology Bv | Cable having strength member with bonded polymer coatings to create continuously bonded jacketed strength member system |
ES2648239T3 (en) * | 2012-01-12 | 2017-12-29 | Otis Elevator Company | Reinforced belt and method to manufacture it |
JP5868486B2 (en) * | 2012-02-27 | 2016-02-24 | 三菱電機株式会社 | Method for detecting deterioration of resin film and apparatus for detecting deterioration of resin film |
WO2015100528A1 (en) * | 2013-12-30 | 2015-07-09 | Nv Bekaert Sa | Open rope for hoisting |
RU174518U1 (en) * | 2015-02-12 | 2017-10-18 | Общество с ограниченной ответственностью "Научно-производственный центр "Гальва" | Steel strand rope with polymer material |
DE102015222272A1 (en) * | 2015-11-12 | 2017-05-18 | Contitech Transportbandsysteme Gmbh | Method for producing a tension member and tension members |
KR101680284B1 (en) | 2016-02-05 | 2016-11-29 | 조명현 | Composite Polymer |
KR101913075B1 (en) | 2018-05-30 | 2018-10-29 | 조대용 | Wire rope having enhanced quality properties |
KR101913074B1 (en) | 2018-05-30 | 2018-12-28 | (주)씨에스 | Method 0f wire rope having enhanced quality properties |
Citations (3)
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WO2003044267A1 (en) * | 2001-11-23 | 2003-05-30 | N.V. Bekaert S.A. | Cable and window elevator system using such cable |
WO2004076327A1 (en) * | 2003-02-27 | 2004-09-10 | N.V. Bekaert S.A. | An elevator rope |
WO2005043003A1 (en) * | 2003-11-03 | 2005-05-12 | Nv Bekaert Sa | Fine steel cord with a low structural elongation |
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US3133584A (en) * | 1962-07-12 | 1964-05-19 | Nat Standard Co | Rope construction |
NL299306A (en) * | 1963-10-14 | |||
US3778994A (en) * | 1971-03-30 | 1973-12-18 | Bethlehem Steel Corp | Corrosion resistant wire rope and strand |
JPS59125988A (en) * | 1982-12-27 | 1984-07-20 | 朝日ミニロ−プ販売株式会社 | Drive rope for electronic machinery |
DE3317712C2 (en) * | 1983-05-16 | 1986-10-30 | Akzo Gmbh, 5600 Wuppertal | Reinforcement cord for reinforcing elastomeric products |
EP1000194B1 (en) | 1997-07-29 | 2002-09-04 | Bekaert Naamloze Vennootschap | Steel cord for protection plies of pneumatic tyres |
US7426821B2 (en) * | 2002-07-17 | 2008-09-23 | Nv Bekaert Sa | Metal strand comprising interrupted filament |
US6811877B2 (en) * | 2003-02-21 | 2004-11-02 | The Goodyear Tire & Rubber Company | Reinforcing structure |
-
2007
- 2007-01-08 EP EP07000237A patent/EP1942224A1/en not_active Withdrawn
-
2008
- 2008-01-04 ES ES08701235T patent/ES2387220T3/en active Active
- 2008-01-04 KR KR1020097014218A patent/KR101444488B1/en active IP Right Grant
- 2008-01-04 JP JP2009545160A patent/JP5289329B2/en active Active
- 2008-01-04 CN CN2008800018760A patent/CN101578415B/en active Active
- 2008-01-04 PL PL08701235T patent/PL2104764T3/en unknown
- 2008-01-04 WO PCT/EP2008/050053 patent/WO2008084010A1/en active Application Filing
- 2008-01-04 US US12/522,332 patent/US20100009184A1/en not_active Abandoned
- 2008-01-04 PT PT08701235T patent/PT2104764E/en unknown
- 2008-01-04 EP EP08701235A patent/EP2104764B1/en active Active
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2003044267A1 (en) * | 2001-11-23 | 2003-05-30 | N.V. Bekaert S.A. | Cable and window elevator system using such cable |
WO2004076327A1 (en) * | 2003-02-27 | 2004-09-10 | N.V. Bekaert S.A. | An elevator rope |
WO2005043003A1 (en) * | 2003-11-03 | 2005-05-12 | Nv Bekaert Sa | Fine steel cord with a low structural elongation |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010052075A1 (en) * | 2008-11-10 | 2010-05-14 | Contitech Antriebssysteme Gmbh | Traction mechanism, tractive drive comprising said traction mechanism, and lift installation |
CN102209678A (en) * | 2008-11-10 | 2011-10-05 | 康蒂泰克驱动系统有限公司 | Traction mechanism, tractive drive comprising said traction mechanism, and lift installation |
Also Published As
Publication number | Publication date |
---|---|
CN101578415A (en) | 2009-11-11 |
EP2104764A1 (en) | 2009-09-30 |
WO2008084010A1 (en) | 2008-07-17 |
JP2010515833A (en) | 2010-05-13 |
EP2104764B1 (en) | 2012-06-27 |
JP5289329B2 (en) | 2013-09-11 |
PT2104764E (en) | 2012-08-23 |
KR101444488B1 (en) | 2014-09-24 |
ES2387220T3 (en) | 2012-09-18 |
PL2104764T3 (en) | 2012-10-31 |
US20100009184A1 (en) | 2010-01-14 |
CN101578415B (en) | 2012-08-22 |
KR20090097186A (en) | 2009-09-15 |
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