Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C1/00—Manufacture of metal sheets, wire, rods, tubes or like semi-manufactured products by drawing
  • B21C1/02—Drawing metal wire or like flexible metallic material by drawing machines or apparatus in which the drawing action is effected by drums
  • B21C1/12—Regulating or controlling speed of drawing drums, e.g. to influence tension; Drives; Stop or relief mechanisms
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C1/00—Manufacture of metal sheets, wire, rods, tubes or like semi-manufactured products by drawing
  • B21C1/02—Drawing metal wire or like flexible metallic material by drawing machines or apparatus in which the drawing action is effected by drums
  • B21C1/04—Drawing metal wire or like flexible metallic material by drawing machines or apparatus in which the drawing action is effected by drums with two or more dies operating in series
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C1/00—Manufacture of metal sheets, wire, rods, tubes or like semi-manufactured products by drawing
  • B21C1/16—Metal drawing by machines or apparatus in which the drawing action is effected by means other than drums, e.g. by a longitudinally-moved carriage pulling or pushing the work or stock for making metal sheets, rods or tubes
  • B21C1/32—Feeding or discharging the material or mandrels
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C19/00—Devices for straightening wire or like work combined with or specially adapted for use in connection with drawing or winding machines or apparatus
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
  • C21D1/26—Methods of annealing
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D7/00—Modifying the physical properties of iron or steel by deformation
  • C21D7/02—Modifying the physical properties of iron or steel by deformation by cold working
  • C21D7/10—Modifying the physical properties of iron or steel by deformation by cold working of the whole cross-section, e.g. of concrete reinforcing bars
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D8/00—Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
  • C21D9/54—Furnaces for treating strips or wire
  • C21D9/56—Continuous furnaces for strip or wire
  • C21D9/562—Details
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
  • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
  • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
  • C21D9/54—Furnaces for treating strips or wire
  • C21D9/56—Continuous furnaces for strip or wire
  • C21D9/60—Continuous furnaces for strip or wire with induction heating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
  • B21C51/00—Measuring, gauging, indicating, counting, or marking devices specially adapted for use in the production or manipulation of material in accordance with subclasses B21B - B21F
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21F—WORKING OR PROCESSING OF METAL WIRE
  • B21F1/00—Bending wire other than coiling; Straightening wire
  • B21F1/02—Straightening

Definitions

• the present invention concerns a production line and an associated method for automatically producing threadlike metal products, for example made of steel, in particular strands, intended as ropes or cables, consisting of several wires intertwined with each other, possibly on a central core, which can consist of one of the wires.
• the production line and the method according to the present invention can be applied in the field of mechanical processing to transform raw products, or semi-finished products, into other more specific products, which can then be used in the construction sector in general, or in various civil infrastructures, such as for example low relaxation steel wires for prestressed reinforced concrete and structural reinforcement.
• production lines are known in which, by means of substantially cold mechanical processing, or mechanical processing with some heat treatment, it is possible to produce threadlike metal products, such as wires and strands, in particular made of low relaxation steel for prestressed reinforced concrete and structural reinforcement.
• high carbon steel wire either on its own or braided in the form of a strand of two or more wires, according to techniques known to the people of skill in the art, can be used as structural reinforcement in a wide field of applications, such as large industrial or civil engineering works, such as for example beams for structures of buildings, in particular multi-story ones, pylons, bridges, tensile structures, port docks, highway barriers, high-speed railway sleepers, reinforced concrete pipes, giant suspension cables for cable stayed bridges, or suchlike.
• the steel wire has to have low relaxation characteristics when subjected to the continuous application of strong axial loads, particularly when coupled with concrete.
• a stress relieving treatment subjecting it to a load equal to about 40% of the breaking limit while it is heated to a temperature of about 400°C, with subsequent rapid cooling.
• the same Applicant has successfully designed, perfected, built and installed two different production lines for automatically producing threadlike metal products: a first, about 90 m long called “PC WIRE”, for producing single wires starting from a motorized bobbin from which a raw wire, with a diameter comprised between about 3 mm and about 12 mm, is pulled by a single drawing unit to be subjected to mechanical and thermal processing which stabilize it, so that it can then be wound into a strapped spool; a second line, about 110 m long called “PC STRAND”, for producing strands consisting of a plurality of wires, for example seven, coming from corresponding bobbins associated with a stranding machine and pulled together by a first drawing unit, after the wires themselves have been braided together to form the strand, which
• the processing speed at which the wire travels reaches 500 m/min, which allows to achieve high productivity, that is, from about 1400 to over 5000 kilograms mass per hour (kg/h), which corresponds to between approximately 10,000 and over 36,000 nominal tons per year (t/y), depending on the diameter of the wires produced.
• the processing speed at which the strand travels is lower, since the weight of the strand per linear meter is greater than that of the single wire, and reaches 170 m/min, which in any case allows to obtain a high productivity, that is, from about 1,000 to over 11,300 kilograms mass per hour (kg/h), which corresponds to between approximately 7200 and over 81,000 nominal tons per year (t/y), depending on the diameter of the strands produced.
• a post- forming operation upstream of the first drawing unit, the purpose of which is to straighten the strand and make it rectilinear before it enters the first drawing unit. This post-forming operation can be carried out for example by means of rows of staggered rollers between which the single wire slides.
• Upstream of the first drawing unit there is also a load cell designed to detect the pull of the single wire before it enters into the first drawing unit.
• the drawing unit with variable pull can also generate operating problems on the post- forming apparatus. For example, it is possible that the rollers of the post-forming apparatus may become excessively worn.
• one purpose of the present invention is to create a production line and to perfect a method for automatically producing threadlike metal products, with which it is possible to produce, by choice and automatically, strands of high stability and final quality, for example in terms of structural resistance and straightness.
• Another purpose of the present invention is to create a production line and perfect a method for automatically producing threadlike metal products, which are reliable and highly efficient, and which allow to obtain high productivity.
• Another purpose of the present invention is to create a production line and perfect a method for automatically producing threadlike metal products in which the first drawing unit receives a strand directly from feed means and therefore is not subjected to processes which can negatively impact the pull at entry to this first drawing unit, for example causing a change in the pull.
• the Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.
• the production line comprises: a first measuring device configured to detect the pull on the strand as it exits the first drawing unit; a post-forming apparatus substantially configured to confer straightness on said strand; a second measuring device, configured to detect the pull on the strand; and a second drawing unit configured to draw the strand exiting from said post-forming apparatus.
• the first drawing unit is not negatively affected by variations in the pull caused by the post-forming operation. Furthermore, the post-forming apparatus also works effectively, is less affected by wear phenomena compared with what happens in known production lines and allows to obtain a stable strand of high quality and straightness, which substantially does not require further straightening operations before leaving the production line.
• the production line comprises a control unit configured to receive the data relating to the pulls, to process them and send an overall pull value for the strand to the second drawing unit.
• treatment means configured to carry out at least thermal processing on the strand are provided between the postforming apparatus and the second drawing unit.
• the treatment means comprise in sequence heating means configured to stabilize the strand and a cooling apparatus.
• the heating means comprise an induction furnace configured to heat the strand to a temperature comprised between approximately 350°C and approximately 410°C.
• the heating means are mobile selectively and alternatively along a longitudinal axis of the production line between a first position and a second position and vice versa.
• the treatment means comprise an apparatus for washing the strand located upstream of the heating means.
• the production line comprises an apparatus, called “dancer”, located downstream of the second drawing unit.
• the production line comprises a collection unit configured to collect, in particular in the form of coils, skeins, or suchlike, the strand at the end of the production cycle.
• Another purpose of the present invention is a method for automatically producing metal products in the form of strands, comprising a step of feeding a plurality of wires to form a strand, drawn by a first drawing unit.
• the method also comprises: a step of measuring the pull on the strand by means of a first measuring device; a step of conferring substantial straightness to the strand by means of a post-forming apparatus; a subsequent step of measuring the pull on the strand by means of a second measuring device; and a step of drawing the strand exiting from the postforming apparatus by means of a second drawing unit.
• FIG. 1 is a block diagram of a production line according to the present invention, for automatically producing threadlike metal products
• - fig. 2 is a lateral view of a first portion of the production line of fig. 1 ;
• - fig. 3 is a lateral and partly sectioned view of a second portion of the production line of fig. 1 ;
• - fig. 4 is a top view of a part of the second portion of the production line of fig. 3;
• - fig. 5 is an enlarged and sectioned detail of a part of a drawing pulley of the production line of fig. 1 ;
• - fig. 6 is a lateral view of a third portion of the production line of fig. 1 ;
• - fig. 7 is a lateral and partly sectioned view of a fourth portion of the production line of fig. 1.
• a production line 10 for automatically producing metal products 11 (figs, from 3 to 7), for example made of steel, and threadlike, that is, in the form of strands 12 (fig. 5) formed by braiding multiple wires 13, comprises a plurality of operating units 16 (fig. 1), installed on a base 18 (figs. 2, 3, 6 and 7), for example consisting of a floor of a suitable establishment, and aligned in sequence along a longitudinal axis X (figs, from 1 to 4, 6 and 7), preferably horizontal.
• the production line 10 can operate to produce the strand 12 or a single wire 15, see in particular fig. 5.
• the production line 10 and in particular the operating units 16 comprise: feed means 19, 38 configured to feed a plurality of wires 13 to form the strand 12 and a first drawing unit 22 positioned downstream of the feed means 19, 38 and configured to receive the strand 12.
• the production line 10 comprises in sequence: a first measuring device 23 located downstream of the first drawing unit 22 and configured to detect the pull T1 on the strand 12 as it exits the first drawing unit 22; a post- forming apparatus 26; a second measuring device 50, configured to detect the pull T2 on the strand 12 downstream of the post- forming apparatus 26; and a second drawing unit 32 configured to draw the strand 12 exiting the post-forming apparatus 26.
• the operating units 16 can also comprise: a washing apparatus 29; heating means 30; a cooling apparatus 31; a strand winding apparatus 33, such as for example a winding apparatus known in the sector by the name “dancer”; and a collection unit 35.
• the production line 10, in its extension along the longitudinal axis X, is approximately 120 m long.
• the production line 10 comprises a control unit 36 configured to receive the data relating to the pull Tl, T2, to process them and send an overall pull value T for the strand 12 to a second drawing unit 32 located downstream of the postforming apparatus 26.
• the pull T is in particular the sum of the pulls T1 and T2.
• control unit 36 for example of the electronic and programmable type, which together with a plurality of sensors and other detection devices, of a known type and not shown in the drawings, constitute the control means of the production line 10.
• the feed apparatus 19 and the single feed bobbin 21 constitute the feed means of the production line 10, in order to produce the single wire 15.
• the feed apparatus 19 for the production of the strand 12 can be of any known type whatsoever and contain for example a plurality of feed bobbins 38 (fig. 2), for example between two and eighteen, in particular seven in the embodiment shown here, of which one is central and the other six are disposed interwoven around it.
• Each feed bobbin 38 can contain, wound into coils, a wire 13 (fig. 5) having a certain diameter DI comprised, for example, between 2 mm and 10 mm, and with a length of a few thousand meters.
• the single feed bobbin 21 for the production of the single wire 15 can in practice be one of the feed bobbins 38.
• the feed line 10 can comprise a stranding machine 20 of any known type, disposed close to the outlet of the feed apparatus 19 and configured to receive the plurality of wires 13 (fig. 5) and transform them into a strand 12 having a certain diameter D2, for example from about 4 mm to about 25 mm, and a certain programmable pitch.
• the stranding machine 20 can be by-passed or said single wire 15 can pass through it remaining unchanged.
• the single feed bobbin 21 (figs. 1, 3 and 4) can be of any known type whatsoever, and the single wire 15 is wound onto it, which substantially has the sizes of one of the wires 13.
• the single feed bobbin 21, if necessary, is able to be selectively displaced laterally with respect to the longitudinal axis X, for example when the production line 10 is used to produce the strands 12.
• the first drawing unit 22 is disposed inside a first cavity 39 (figs. 3 and 4) created in the base 18, with a parallelepiped shape and having, for example, sizes of about 7.5 m x 5 m and a depth of about 3 m. Service steps 40 (fig. 4) are present to access the bottom of the first cavity 39.
• the first drawing unit 22 comprises two identical drawing pulleys 41 and 42 (figs.
• the axis of rotation Y1 of the first drawing pulley 41 that is, the one positioned closest to the single feed bobbin 21 , is lower (fig. 3) by about 400 mm compared to the axis of rotation Y2 of the other, or second, drawing pulley 42.
• the external diameter D3 of the two drawing pulleys 41 and 42 is advantageously about 3 m and the center distance between the two axes of rotation Y1 and Y2 is about 3.5 m.
• the two drawing pulleys 41 and 42 are connected, or attached, respectively, to the shafts of two electric motors 43 and 44 (fig. 4), coaxial to the axes of rotation Y1 and Y2. Furthermore, the shafts of the two electric motors 43 and 44 are mechanically connected to each other, for example by means of a drive belt 45 (fig. 4) and two driving pulleys 46 and 48, with a smaller diameter than that of the two drawing pulleys 41 and 42, so that the latter rotate at the same peripheral speed, which substantially or almost corresponds to the drawing speed Vt (fig. 3) of the products 11 , when the two electric motors 43 and 44 are energized, or only one of them is energized, as will be described in detail below.
• Each of the two drawing pulleys 41 and 42 is shaped in such a way as to have a plurality of circular grooves 49 (fig. 5) on its periphery, for example five in the embodiment shown here, preferably equidistant from each other and each having a V-shaped cross section, with a flaring angle oc comprised between about 25° and about 50°, preferably of about 38°.
• the depth P of each circular groove 49 is such as to house the strand 12 between its walls, regardless of its diameter D2, and is for example comprised between about 26 mm and about 34 mm, preferably of about 30 mm.
• the radius of curvature of the bottom of each circular groove 49 is substantially equal to half the diameter DI of the single wire 15.
• the drawing pulleys 41 and 42 can draw the products 11, be they strands 12 or single wires 15, without creating reciprocal sliding between them, thus guaranteeing a high precision drawing.
• the two drawing pulleys 41 and 42 (figs. 3 and 4) have the function of horizontal axis capstans, and the strand 12 or the single wire 15 is wound onto them, as in a block, making it pass with several turns, for example five, from one circular groove 49 to the adjacent one, starting from one of the two outermost circular grooves 49.
• the two electric motors 43 and 44 are commanded by the control unit 36 so that the tractive force F applied on the strand 12, or on the single wire 15, by the first drawing unit 22 is approximately equal to a value comprised between 40% and 45% of their breaking load.
• the electric motors 43 and 44 can be commanded by a single electric inverter of a known type, for example of 440 KW.
• the first measuring device 23 (figs. 3 and 4) can be of any known type whatsoever and comprises, for example, load cells not shown in the drawings and configured to measure the load present on the strand 12 or on the single wire 15 immediately downstream of the first drawing unit 22 and before the subsequent processing.
• the indenting apparatus 25 (fig. 3) can be of any known type whatsoever and is configured to create a plurality of teeth, or protrusions and/or grooves, on the peripheral surface of the single wire 15. In the production of strands 12, the indenting apparatus 25 can be by-passed or the strand 12 can pass through it remaining unchanged.
• the post-forming apparatus 26 is configured to perform, in a known manner, a post- forming treatment on the strand 12 or on the single wire 15, for example an operation of alignment of the strand 12 or of the single wire 15.
• the post-forming apparatus 26 is thus configured to confer straightness on the strand 12 or on the single wire 15.
• the post-forming apparatus 26 is associated with or located upstream of the second measuring device 50, also of a known type and comprising for example other load cells not shown in the drawings.
• the second measuring device 50 is configured to measure the load present on the strand 12 or on the single wire 15 after the operation carried out with the post-forming apparatus 26 and the elongation that the strand 12 or the single wire 15 undergo, which is of the order of about 1% to 1.5%.
• the post-forming apparatus 26 can be housed on a counter 54, with which the second measuring device 50 can be associated.
• the counter 54 is a sort of cradle under which the second measuring device 50 is positioned.
• the washing apparatus 29 can be of any known type whatsoever and is configured to wash the strand 12 or the single wire 15 downstream of the indenting and post-forming operations.
• the heating means 30 (figs. 1 and 6) comprise a heating furnace 30, for example an induction furnace, which can be of any known type whatsoever, for example modular and selectively and alternately mobile along the longitudinal axis X between a first position A (fig. 6) and a second position B, and vice versa, and it has the function of carrying out a heating operation of the strand 12 or of the single wire 15, for example to a temperature comprised between about 350°C and about 410°C, in order to stabilize the strand 12 or the single wire 15.
• the heating means 30 are mobile for example to facilitate and speed up the approach of the single wire 15 to be cooled toward the cooling apparatus 31 and resume the segment not heated during an emergency stop, even in the event of breakage of the single wire 15.
• the cooling unit 31 can be of any known type whatsoever and is configured to cool the strand 12 or the single wire 15, after the heating and stabilization operation.
• the processing means 51 can also comprise the washing apparatus 29.
• the second drawing unit 32 (figs. 1 and 7) is substantially the same as the first drawing unit 22, except for the fact that the axes of rotation of the two drawing pulleys, designated as 41 A and 42 A (fig. 7), lie on a same plane parallel to the longitudinal axis X, so it is not described in detail again.
• the second drawing unit 32 (figs. 1 and 7) is substantially the same as the first drawing unit 22, except for the fact that the axes of rotation of the two drawing pulleys, designated as 41 A and 42 A (fig. 7), lie on a same plane parallel to the longitudinal axis X, so it is not described in detail again.
• the second drawing unit 32 (figs. 1 and 7) is substantially the same as the first drawing unit 22, except for the fact that the axes of rotation of the two drawing pulleys, designated as 41 A and 42 A (fig. 7), lie on a same plane parallel to the longitudinal axis X, so it is not described in detail again.
• the second drawing unit 32 (figs
• the winding apparatus 33 can be of any known type whatsoever, for example a so-called “dancer” that uses the principle of inertia compensation and effectively absorbs any tension imbalances and guarantees constant winding tension.
• the tension is adjusted and maintained thanks to a feedback of its own up and down movement, through an encoder and a pneumatic cylinder controlled by a proportional valve modifying the weight force.
• the collection unit 35 is configured to collect, for example in the form of bobbins, or spools, the strand 12 or the single wire 15 after the processing cycle is complete.
• the collection unit 35 comprises a pair of reels 53 which can be of any known type whatsoever.
• the present method for automatically producing the products 11 essentially comprises the following steps, made in sequence, for example coordinated and commanded by the control unit 36: a step of feeding the plurality of wires 13 to form the strand 12 and of drawing the strand 12 by means of the first drawing unit 22; a step of measuring the pull T1 on the strand 12 downstream of the first drawing unit 22 by means of the first measuring device 23; a step of conferring substantial straightness on the strand 12 by means of the post- forming apparatus 26; a step of measuring the pull T2 on the strand 12 by means of the second measuring device 50; and a step of drawing the strand 12 exiting from the post- forming apparatus 26 by means of the second drawing unit 32. It is clear that modifications and/or additions of parts or steps may be made to the production line 10 and to the method for automatically producing threadlike metal products as described heretofore, without departing from the field and scope of the present invention, as defined by the claims.
• the wire In the preparation of the wire rod or starting metal product, the wire can be pickled with hydrochloric/phosphoric acid or with mechanical cleaning. It is then coated with zinc and calcium phosphate crystals in order to improve corrosion resistance and the friction coefficient, favoring cold-drawing or cold-rolling.
• the electrochemical deposit is about 6 mm/m2, which corresponds to 0.03 mm of thickness.
• a corrosion protection system can be provided with an emulsion (water-oil with about 8/12% oil), which covers the strand or wire for about 0.05 mm, before the final winding, with great energy savings.
• the corrosion protection device can be any, for example a vacuum generator that, by exploiting the Venturi effect, when the compressed air passes it sucks the emulsion which, mixing with the air, is sprayed onto the material being processed. The device allows to dose the compressed air being expelled and the amount of emulsion required by the diameter of the strand or wire and by the production speed.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Crystallography & Structural Chemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Wire Processing (AREA)

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• 2023
  • 2023-01-27 IT IT102023000001206A patent/IT202300001206A1/it unknown
• 2024
  • 2024-01-26 WO PCT/IT2024/050019 patent/WO2024157299A1/en not_active Ceased
  • 2024-01-26 EP EP24708905.5A patent/EP4655114A1/de active Pending

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