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Title:
MULTI-WIRE PLATING LINE AT VARIOUS LEVELS
Document Type and Number:
WIPO Patent Application WO/2013/117269
Kind Code:
A1
Abstract:
A process of sequentially plating a plurality of elongated metal members (100, 200) in two or more plating cells (102, 110, 116, 126) comprises the following steps: a) guiding the plurality of elongated metal members (100, 200) at a first level in first direction through a first plating bath (102, 202); b) forcing the plurality of elongated metal members (100, 200) to make a 180 degree turn and to go to a second level different from the first level and guiding the plurality of elongated metal members (100, 200) in a second direction opposite to the first direction through a second plating bath (110, 214); c) forcing the plurality of elongated metal members (100, 200) again to make a 80 degree turn and to go to a third level different from the first level and different from the second level and guiding the plurality of elongated metal members (100, 200) in the first direction. By using various levels, space can be saved and flexibility can be built in existing plating lines.

Inventors:
BUYTAERT GUY (BE)
DEWEER FILIP (BE)
Application Number:
PCT/EP2012/075240
Publication Date:
August 15, 2013
Filing Date:
December 12, 2012
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
BEKAERT SA NV (BE)
International Classes:
C25D7/06; C23C18/16; C25D17/00
Foreign References:
CN1127309A1996-07-24
DE8115269U11981-08-13
US2667453A1954-01-26
US3947343A1976-03-30
CN1127309A1996-07-24
US3947343A1976-03-30
Attorney, Agent or Firm:
MESSELY, Marc et al. (Bekaertstraat 2, Zwevegem, BE)
Download PDF:
Claims:
Claims

1 ) A process of sequentially plating a plurality of elongated metal members in two or more plating cells, said process comprising the following steps:

a) guiding said plurality of elongated metal members at a first level in a first direction through a first plating bath;

b) forcing said plurality of elongated metal members to make a 180 degree turn and to go to a second level different from said first level and guiding said plurality of elongated metal members in a second direction opposite to said first direction through a second plating bath;

c) forcing said plurality of elongated metal members again to make a 180 degree turn and to go to a third level different from said first level and different from said second level and guiding said plurality of elongated metal members in said first direction.

2) A process according to claim 1 , wherein said elongated metal members, after having gone through said second plating bath, are guided in step b. in said second direction at said second level through a second rinsing bath.

3) A process according to claim 1 , wherein said elongated metal members are guided in step c. in said first direction at said third level through a second rinsing bath.

4) A process according to claim 3, wherein said second plating bath is positioned at a first horizontal position and wherein said second rinsing bath is positioned at a second horizontal position, said first horizontal position not overlapping with said second horizontal position thereby avoiding spilling out from said rinsing bath to said plating bath or the other way around.

5) A process according to any one of the preceding claims wherein said plurality of wires are further guided from said third level back to said first level in said first direction. 6) A process according to any one of the preceding claims wherein said second level is higher than said first level.

7) A process according to claim 6, wherein said third level is higher than said second level.

8) A process according to claim 7, said process further providing a containment base under said second level and said third level in order to prevent liquids from getting to the ground level.

9) An installation for sequentially plating a plurality of elongated metal members in two or more plating cells, said installation comprises:

a) a first plating bath positioned at a first level;

b) means for guiding said plurality of elongated metal members through said first plating bath;

c) a second plating bath positioned at a second level different from said first level;

d) means for forcing said plurality of elongated metal members to make a 180 degree turn and to go to said second level in a second direction opposite to said first direction;

e) means for guiding said plurality of elongated metal members through said second plating bath;

f) means for forcing said plurality of elongated metal members again to make a 180 degree turn and to go to a third level different from said first level and different from said second level;

g) means for guiding said plurality of elongated metal members in said first direction at said third level.

Description:
MULTI-WIRE PLATING LINE AT VARIOUS LEVELS

Description

Technical Field

[1 ] The invention relates to a process of sequentially plating a plurality of elongated metal members and to an installation for sequentially plating a plurality of elongated metal members.

Background Art

[2] Processes and installations for sequentially plating a plurality of elongated metal members such as steel wires are generally known in the art. For example in the process for manufacturing steel cords for tire

reinforcement, it is standard practice to firstly plate the steel wires with copper and thereafter with zinc. A diffusion process follows the copper and zinc coating in order to create a brass coating on the steel wire. As a matter of another example, steel wires for use in aquaculture nets preferably have a copper-nickel alloy coating. This coating may be applied by means of a copper plating and a nickel plating followed by a thermo-diffusion process.

[3] These existing multi-wire installations have proven to be excellent for providing wires with a specific coating composition and a specific coating thickness. As soon as one desires to have wires with a differing coating composition or with another coating thickness, adaptation of these installations appears to be time-consuming.

[4] These multi-wire plating installations usually comprise other modules such as pickling, rinsing, fluxing, heat treating, ... As a result these installations are quite lengthy and occupy a lot of space, and there is not always space for other designs in the line architecture.

[5] CN-A-1 127 309 discloses a process of sequentially plating a plurality of elongated metal members in two electroplating cells where one

electroplating cell is positioned above the other. However, this process not adapted make existing plating lines more flexible. Moreover, the unwinding operation and winding up operation of the elongated nnetal members occur at the same side of the installation, which complicates heavily the handling.

Disclosure of Invention

[6] The primary object of the invention is to provide a multi-wire installation and process which allows more flexibility.

[7] Another object of the invention is to provide a multi-wire installation and process which saves space.

[8] Still another object of the invention is to provide a multi-wire installation and process which allows to make use of existing installations.

[9] Yet another object of the invention is to provide a multi-wire installation and process which allow a certain product mix to be made.

[10] According a first aspect of the invention, there is provided a process of sequentially plating a plurality of elongated metal members in two or more plating cells. The process comprises the following steps:

guiding the plurality of elongated metal members at a first level in a first direction through a first plating bath and possibly through a first rinsing bath;

forcing the plurality of elongated metal members to make a 180 degree turn and to go to a second level different from the first level and guiding the plurality of elongated metal members in a second direction opposite to the first direction through a second plating bath;

forcing the plurality of elongated metal members again to make a 180 degree turn and to go to a third level different from the first level and different from the second level and guiding the plurality of elongated metal members in the first direction.

[1 1 ] Examples of elongated metal members are steel wires, steel cords, steel fibers, copper wires,... [12] US-A-3,947,343 discloses a process and apparatus for degreasing and electroplating a copper wire with tin. In contrast with the present invention, it is a single-wire line. In order to have the plating line working at a high speed and still keep the length dimensions of the line limited, the copper wire is making various loops and is travelling several times through two plating cells which are positioned one above the other. With a multi-wire line it would not be possible to make a number of loops through the same plating and degreasing cells.

[13] Referring again to the invention, by positioning plating cells at various

levels and by making two times a 180 degree turn, it is possible to make the multi-wire processing flexible and yet save space. For example, in one embodiment, some plating cells may be skipped while in another embodiment all plating cells are used.

[14] Additionally by positioning plating cells at various levels, existing lines may be upgraded for a greater product mix without necessitating more length by adding one or more additional plating cells to the lines.

[15] In a first embodiment of the process and after having gone through the second plating bath, the elongated metal members are guided in step b. in the second direction at the second level through a second rinsing bath.

[16] In a second embodiment of the process the elongated metal element are guided in step c. in the first direction at the third level through a second rinsing bath.

[17] In a preferable design of this embodiment, the second plating bath is

positioned at a first horizontal position. The second rinsing bath is positioned at a second horizontal position. The first horizontal position does not overlap with the second horizontal position thereby avoiding spilling out from the rinsing bath to the plating bath or from the plating bath into the rinsing bath.

[18] Preferably after having gone from the first level to the second and third level, the plurality of elongated metal members are guided back from the third level to the first level in the first direction.

Usually an existing installation is only positioned at the first level.

According to this invention, the second level and the third level are added and provide possibilities for additional plating. After having passed this additional plating at the second level and the third level, the elongated metal members are guided back to the first level in the first direction. No change in rest of the line such as further plating or winding equipment is required.

[19] Most preferably, the upper level has a containment base to prevent liquids such as electrolytes, acids, chemicals from getting to the ground level. The containment base should avoid that spill of plating solution or rinsing water becomes a danger for operators on the ground floor. The

containment base should also avoid great splashes of liquids created on the ground floor. In addition, a containment base is very useful in control of further disposal of liquids in case of leakage or accident.

[20] As an alternative to the invention, one plating cell may be at ground level while another plating cell may be at a basement level. The terms

"basement level" refer to a level lower than ground level and such that a plating cell at ground level may be positioned above a plating cell at basement level.

[21 ] Plating cells may be positioned one above the other or not.

[22] The plating cell may be an electro-plating cell or a chemical or electroless plating cell.

[23] In the various plating cells of the invention the same or a different metal can be plated on the elongated metal elements.

[24] According a second aspect of the invention there is provided an

installation for sequentially plating a plurality of elongated metal members. The installation comprises two or more plating cells. The installation comprises:

a) a first plating bath positioned at a first level;

b) means for guiding said plurality of elongated metal members through the first plating bath;

c) a second plating bath positioned at a second level different from the first level;

d) means for forcing the plurality of elongated metal members to make a 180 degree turn and to go to the second level in a second direction opposite to the first direction;

e) means for guiding the plurality of elongated metal members through the second plating bath;

f) means for forcing the plurality of elongated metal members again to make a 180 degree turn and to go to a third level different from the first level and different from the second level;

g) means for guiding the plurality of elongated metal members in the first direction at the third level.

Brief Description of Figures in the Drawings

[25] Figure 1 is a schematic presentation of a first embodiment of a multi-wire multi-level plating line.

[26] Figure 2 is a schematic presentation of a second embodiment of a multi- wire multi-level plating line.

[27] Figure 3 illustrates the multi-wire aspect of the invention.

Mode(s) for Carrying Out the Invention

[28] Figure 1 illustrates how the multi-level aspect may be applied to build

flexibility into a plating line.

[29] Steel wires 100 are first guided through an electroplating cell 102 for

copper followed by rinsing cells 104. Both the electroplating cell 102 and the rinsing cells 104 are positioned at ground level 106.

The steel wires 100 are electro-negatively loaded and function as cathode.

The plating cell 102 comprises an electrolyte and metal ions of the metal which is to be plated on the steel wires 100. As a matter of example, the electrolyte can be copper-citrate, copper-amine, copper-tartrate, copper- sulphate, copper-pyrophosphate, copper f I uoroborate or copper cyanide. The anode is formed by a soluble copper anode lying on a supporting plate. The cathode current density varies between 1 and 20 A/dm 2 . The speed of the steel wires may vary between 10 m/min and 150 m/min. Four, five or even more rinsing cells 104 may be arranged in cascade. Before entering each rinsing cell, the steel wire is cleaned by means of a wiper.

This wiper can take various forms, such as a mechanical wiper making contact with the wire, a wiper of the suction type where a vacuum is used to suck liquid from the wire, a wiper using pressurized air directed to the wire to wipe off the dragged liquid, or a wiper in the form of a narrow tube.

[30] Thereafter the steel wires 100 are guided through guiding rolls 108 and

109 to a higher level where they pass through a second electroplating cell

1 10 for copper. Guiding rolls 1 12, 1 13 bring the steel wires 100 to an even higher level and guide the steel wires 100 through rinsing cells 1 14.

[31 ] The steel wires 100 remain for a while at this higher level and go through a first electroplating cell 1 16 for zinc.

The zinc electroplating cell 1 16 may contain zinc cyanide, zinc sulphate, zinc chloride, zinc fluoroborate, and zinc pyrophosphate.

Guiding rolls 1 18, 1 19 bring the steel wires 100 to a somewhat lower level and guide the steel wires 100 through rinsing cells 120.

[32] A containment floor 122 is provided as base for cells 1 10, 1 14, 1 16 and 120. This containment floor 122 preferably comprises borders or edges for preventing liquids from flowing over to the ground floor 106. The containment floor 122 is made of a material that is resistant against the chemicals used in the plating baths. The containment floor may contain slots to allow the steel wires 100 to pass. These slots are preferably also provided with borders or edges.

[33] Guiding rolls 123, 124 bring the steel wires 100 back to the ground floor 106 where the steel wires undergo a second plating with zinc in an electroplating bath 126. A set of rinsing cells 128 is positioned downstream the zinc plating cell 126.

[34] At the upper level, the rinsing cells 1 14 are preferably not positioned

immediately above the plating cell 1 10. The same holds for plating cell 1 16 which is preferably not positioned above the rinsing cells 120. This is done in order to avoid spill out from one cell to the cell below. In case appropriate measures are taken to avoid this spill out, more compact positioning, one above the other, becomes possible.

[35] The installation of Figure 1 may be used as follows.

In case only a thin coating of brass (= copper + zinc + followed by thermo- diffusion) is needed, as is the case with steel wires for steel tire cord, the steel wires 100 may run straight ahead and may skip the plating cells and rinsing cells at the upper level.

In case a thicker coating of brass is desired, as is the case with steel wire for reinforcement of rubber hoses, the configuration and wiring of Figure 1 with effective use of the upper level is appropriate. This configuration allows to apply a thicker coating without having to decrease the linear speed of the steel wires 100.

[36] In the configuration of Figure 1 one may skip rinsing cells 104 in case the plating cells 102 and 1 10 have the same electrolyte. The same is true in case plating cells 1 16 and 126 have the same electrolyte, then rinsing cells 120 may be skipped.

[37] Figure 2 illustrates how an existing plating line for a binary alloy coating may be upgraded to a plating line for a ternary alloy coating without necessitating more length.

[38] Steel wires 200 first run through a copper electroplating cell 202 followed by rinsing cells 204. Both the copper electroplating cell 202 and the rinsing cells are positioned at ground level 206.

[39] Thereafter the steel wires 200 undergo a zinc plating in a zinc

electroplating cell 208. Then the steel wires 200 are rinsed in rinsing cells

210. Both the zinc plating cell 208 and the rinsing cells are also positioned at ground level 206. Guiding rolls 21 1 and 212 bring the steel wires 200 to an upper level where the steel wires 200 are plated with a third metal, namely cobalt in an electroless plating cell 214. Other guiding rolls 216, 217 bring the steel wires 200 to an even higher level where the steel wires 200 are rinsed in rinsing cells 218. Both the electroless plating cell 214 and the rinsing cells 218 are positioned on a containment floor 220.

[40] Next to cobalt, other elements with an electrochemical potential greater than zinc, such as iron, nickel, manganese... may be plated upon zinc in an electroless plating cell.

[41 ] Guiding rolls 221 , 222 bring the steel wires 200 back to ground level, after which the steel wires undergo a thermo-diffusion treatment (not shown) in order to create a ternary alloy coating on the steel wires 200.

[42] The configuration and wiring as shown in Figure 2 is the configuration for a ternary alloy copper-zinc-cobalt coating on the steel wires. For the more traditional binary alloy coating of brass the upper level may be skipped.

[43] Figure 1 and Figure 2 only show schematically plating cells and rinsing cells. Very often these plating and rinsing cells are preceded with an installation for heat treatment of the steel wires, such as a furnace for austenitization followed by a patenting bath. In addition, pickling baths and cleaning baths are positioned immediately upstream the plating and rinsing cells.

[44] Figure 3 illustrates the multi-wire aspect of the present invention. The whole installation and each plating cell 300 and rinsing cell are designed to treat simultaneously a plurality of parallel steel wires 302. The number of steel wires 302 running in parallel may vary from twelve over thirty-two to sixty-four and more. The plurality of parallel steel wires 302 are guided to the electrolyte bath 304 and pass over a guiding roll 306 to a higher level (not shown). The above examples are from the field of steel wires for rubber reinforcement.

Similar installations are possible for other fields. For example, steel wires may be coated with copper, nickel and tin in order to provide a corrosion- resistant and anti-fouling coating for aquaculture purposes.

[45] List of Reference Numbers

Figure 1

100 steel wires

102 copper electroplating cell

104 rinsing cells

106 ground level

108 guiding roll

109 guiding roll

1 10 copper electroplating cell

1 12 guiding roll

1 13 guiding roll

1 14 rinsing cells

1 16 zinc electroplating cell

1 18 guiding roll

1 19 guiding roll

120 rinsing cells

122 containment floor

123 guiding roll

124 guiding roll

126 zinc electroplating cell

128 rinsing cell

Figure 2

200 steel wires

202 copper electroplating cell

204 rinsing cells

206 ground level

208 zinc electroplating cell

210 rinsing cells 21 1 guiding roll

212 guiding roll

214 cobalt electroless plating cell

216 guiding roll

217 guiding roll

218 rinsing cell

220 containment floor

221 guiding roll

222 guiding roll

Figure 3

300 multi-wire plating cell 302 steel wires

304 plating bath

306 guiding roll