Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D7/00—Electroplating characterised by the article coated
  • C25D7/06—Wires; Strips; Foils
  • C25D7/0607—Wires
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D3/00—Electroplating: Baths therefor
  • C25D3/02—Electroplating: Baths therefor from solutions
  • C25D3/42—Electroplating: Baths therefor from solutions of light metals
  • C25D3/44—Aluminium
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D7/00—Electroplating characterised by the article coated
  • C25D7/06—Wires; Strips; Foils
  • C25D7/0614—Strips or foils
  • C25D7/0621—In horizontal cells

Definitions

• the invention relates to a process for the electrolytic coating of metallic or non-metallic continuous products with metals or alloys in a continuous process from aprotic water- and oxygen-free electrolytes.
• Another object of the invention is a device for performing this method.
• endless products such as wire, strips, long profiles or tubes have so far been produced in a continuous process by means of aqueous electrolysis processes or by means of melt bath application.
• wire is coated with various coatings such as zinc, nickel or other metals.
• the wire passes through open cleaning and electrolytic coating baths that contain aqueous solutions. In these baths, the respective metal is deposited on the wire.
• the thickness of the coating layer depends on the throughput speed and the electric field strength.
• the deposition rate in this process is quite low over time, and the deposited layer is often very porous and hard. This leads to a lack of corrosion resistance, especially with thin layers. Due to the lack of ductility, cracks in the deposited layer may occur during subsequent deformation processes or the coating may even flake off. Such a layer loses its protective character against corrosion completely and no longer has a decorative surface.
• a further disadvantage is that the electrolytic aqueous separation processes and hot-dip processes produce large amounts of toxic waste air and waste water, which have to be subjected to purification by means of correspondingly complex processes, with toxic hazardous waste always remaining.
• toxic hazardous waste For example, due to the presence of grease residues on the metals to be coated before the alkaline cleaning in the corresponding solutions, residues of organic compounds are formed which, due to the high temperatures in the zinc kettle, which are around 450 ° C, become extremely toxic organic compounds such as Dioxins and furans can react. Metal sludge, old acids and used alkaline cleaners continue to accumulate. In addition to the exhaust gases mentioned above, acid vapors and alkaline vapors also occur.
• hot-dip galvanizing a previously cleaned and activated continuous product, for example a thin wire, is passed through molten, high-purity zinc. These reactions take place at temperatures above 440 ° C, so that in any case a mechanical see influencing of the material to be coated. Certain other base materials to be coated cannot be coated at all due to the high temperatures.
• Another disadvantage is the relative non-uniformity of the applied coating and its very strongly layer-dependent corrosion resistance. As a result of the wiping process, the surface may lack the decorative character entirely. A colored design of the surface is not possible.
• the so-called high-thermal fire aluminizing is known as a further method.
• a wire is drawn through a molten aluminum bath in the same way as for coating with zinc and then subjected to a stripping process.
• layers are obtained which have disadvantages similar to those of the hot-dip galvanizing described above.
• the layers applied by means of fire aluminizing have not proven themselves due to their inadequate purity, high porosity and inevitable oxide inclusions and thus low corrosion resistance. Further disadvantages are that the coating does not look decorative and there is a strong mechanical influence on the material to be coated, in some cases at the temperatures required for the fire aluminizing.
• hot-dip galvanizing can also be combined with hot-dip aluminum.
• the disadvantage is the lack of decorative character.
• galvanic deposition processes of aluminum are known, which take place in aprotic, water- and oxygen-free electrolytes.
• the aluminum is separated from baths containing aluminum alkyl complexes from alkali metal halides and aluminum alkyls.
• Aromatic or aliphatic hydrocarbons are generally used as solvents.
• Such electrolyte solutions are described for example in EP 0 402 761 A and EP 0 084 816 A.
• the technical object of the invention is to provide a method which avoids the above-mentioned disadvantages of the previously known coating methods for continuous products, is inexpensive and leads to a better coating.
• the process should continue to be able to be carried out without changing the base material, in particular at low temperatures.
• This technical problem is solved by a process for the electrolytic coating of metallic or non-metallic continuous products with metals or alloys in a continuous process from aprotic water- and oxygen-free electrolytes, the continuous product being passed via a lock system into an encapsulated coating system located under an inert gas atmosphere and there the subsequent steps at temperatures ⁇ 120 ° C.
• Endless product in the sense of the invention is understood to mean metallic or non-metallic materials which are produced in a rolled-up or folded form and which are continuously moved through the system during the coating in a continuous process.
• This includes, for example, wires of any thickness, strips and long profiles, tubes and similar products.
• Non-aqueous systems are referred to as electrolytes in the sense of the invention, which allow a controlled, pure deposition of the metal or the metal alloy, in particular of aluminum and aluminum alloys, via the electrolysis process without an intermediate or carrier layer.
• wire, strips, long profiles or tubes made of metallic or non-metallic materials are used as continuous products. It is imminent causes that these materials are coated with aluminum or aluminum alloys.
• FIG. 1 shows a process diagram of the process according to the invention.
• Figure 2 shows an image of the lock system
• Figure 3 shows a coating cell.
• Figure 4 shows the contacting cell.
• FIG. 5 shows a diagram of the overall process.
• FIG. 1 shows the individual process steps of the process according to the invention.
• the continuous product is unwound from a reel, for example, and is first introduced into the coating device via a lock.
• a cleaning process can be carried out as soon as it is introduced into the lock system by passing the continuous product over a gas wiping or spray nozzle (see also FIG. 2, number 11).
• the material to be coated is then activated.
• the number 3 denotes a rinsing unit in which the material is rinsed after activation.
• Section 4 describes a deflection unit with one or more rollers. This is used to reduce the overall size of the system and is particularly useful for continuous products with a small diameter.
• the following numbers 5 describe individual contacting cells, numbers 6 the coating cells and numbers 7 the aftertreatment.
• the coated product is then rolled up onto a corresponding reel at the end of the process.
• a chemical or electrical trochemical aftertreatment is associated with a simultaneous or subsequent color design within the surface structure.
• mechanical surface compaction takes place, which leads to a very shiny surface, which is not influenced during the aftertreatment.
• the entire system is designed to be closed via regeneration circuits, and all the liquids used are processed, cleaned and recycled in a recycle process. This is done in particular for the rinsing solutions, the electrolyte solutions and the activation solution, which can be filtered and / or distilled as required.
• the continuous product is passed through the lock system and the rinsing system from at least three chambers, the middle chamber B being filled with a barrier liquid and the outer chamber A containing air and the inner chamber C containing an inert gas (see FIG also Figure 2).
• the continuous products are guided into the chambers via guides which are not gas-tight and liquid-tight, so that the liquid in the chambers partly runs into the neighboring chambers.
• the barrier liquid in the middle chamber B represents a barrier to the air contained in the outer chamber A. Due to the design of the guides between the chambers in a non-liquid-tight form, part of the barrier liquid runs from the middle chamber B into the chambers A and C. This results in a flushing of the imported continuous product.
• the liquid collected in chambers A and C reaches a storage tank via a drain system and is returned to the middle chamber B via a corresponding pump and filter device.
• the rinsing chambers designated in FIG. 5 are constructed in a similar manner, so that here, too, no liquid or gas can get into the subsequent chambers from the baths in front of them.
• the liquid flowing out of the chambers through the overflow or the guides is cleaned via a circulation system and returned to the respective chamber.
• Bushings or rollers are preferably used as guides between the chambers.
• Contact is preferably made in a chamber filled with liquid electrolytes, which contains no anode, the continuous product being passed over a cathodically connected metal contact.
• the liquid level of this contacting cell is preferably lower than that of the neighboring coating cell, so that electrolyte solution can pass through the guides from the coating chamber into the contacting chamber and so the purity of the electrolyte solution cannot be reduced by impurities introduced from the contacting chamber
• the electrolytic coating takes place in a coating chamber which is filled with electrolytic solution, the continuous product being passed through a bushing which is insulated.
• the contacting and coating cells can be arranged in any frequency, depending on the length and size of the system.
• the wire is introduced into the device according to the invention via particularly expediently designed vacuum or liquid lock systems, the latter being designed similarly to the contacting cells between the coating cells. This is possible for both single and multi-wire systems.
• the sealing medium can also be used to clean the wire surface.
• the processes between the lock systems always run completely under an inert atmosphere.
• the wire guides are specifically designed so that the wire is moved through the coating cell at a uniform distance from the anodes serving as coating material, without making electrical contact with adjacent wires or the anode.
• the special feature of the invention is that the wire must also be inside the electrolyte liquid in this area, but the contacting lies outside the direct coating areas.
• the isolation from the environment takes place via flood systems, similar to the lock systems mentioned.
• the contact can be made via spring-loaded bearings
• Contact elements are made by grinding or rolling, whereby a flexible diameter adjustment is possible.
• the wire can be passed through coating units several times through specially designed deflection systems, so that a highly effective system limited to a short length is possible.
• storage containers keep the continuous product in its original position when the system is at a standstill, in order not to get start-up losses in contrast to classic methods.
• the invention ensures that mechanical or physico-chemical stripping processes do not influence the uniformity or homogeneity of the applied surface layer 0. With the method according to the invention, it is possible to easily replace the aluminum electrodes in the coating cells and to restart operation immediately.
• auxiliary units such as filters and storage systems for
• Lock fluid, cleaning media and electrolytes are designed according to the invention so that closed, environmentally independent operation is possible. Waste products are recycled in a concentrated form.
• the described method offers, via the components described according to the invention, the possibility of a chemical passivation of the coating, which represents a significant increase in the corrosion resistance.
• a possible color nuance of the coating itself according to the invention, 5 not as an application, increases the mechanical resistance. This color scheme significantly compared to paints.
• By designing the exit areas of the wire from the coating and rinsing tract in accordance with the invention it is possible to obtain the wire in a dryer or even in a surface-thickened form in the desired colors and corresponding coating conditions.
• Another object of the invention is a device for the electrolytic coating of metallic or non-metallic continuous products with metals or metal alloys in a continuous process from aprotic water and oxygen-free electrolytes consisting of at least one lock system 1, at least one contacting cell 5, at least one coating cell 6, these Any number of modules are connected in series and the entire device is encapsulated airtight.
• a device is also used, for example, to carry out the method according to the invention.
• FIG. 2 shows a view of the lock system 1. It preferably consists of at least three chambers A, B and C, 17, 18, 19, the middle chamber B having a liquid overflow 16 and the chambers A and C being designed as overflow chambers.
• the chambers A, B and C particularly preferably have an outlet 20, 22 and 23, the middle chamber additionally having an inlet 21 through which the sealing liquid collected in the chambers A and C can be returned to the middle chamber B.
• the number 14 denotes a storage tank, the number 15 a corresponding pump.
• the number 9 denotes the wire guide, number 17 denotes the chamber A, number 18 the chamber B and number 19 the Chamber C.
• Number 12 denotes the continuous product which is passed through the chamber and number 11 is a gas scraper or spray nozzle which is preferably used for additional cleaning of the surface of the continuous product 12 which is passed through the system.
• Numbers 24 and 25 are inner chamber walls, the number 13 denotes a removable plate for sockets. This makes it possible to use endless products of different diameters, in which case the corresponding socket must also be used.
• Numeral 10 denotes the liquid level.
• FIGS. 3a, 3b and 3d show different views of the carrier 28 for the continuous product 12 located in the cell.
• FIG. 3a shows a front view
• FIG. 3b a side view
• FIG. 3d a top view
• FIG. 3c is a perspective view of the entire coating cell 6.
• the number 28 denotes the carrier made of insulating material.
• Numeral 27 shows the ceramic bushing, which is divided into two parts. It is arranged so that it can be removed from the insulating material in the opposite direction to the running direction of the introduced continuous product and can be exchanged, for example, for bushings with a different diameter.
• FIG. 3 c shows the entire coating cell 6 with the anode plates 26 and the carrier 28 and the bushing 27 arranged in the middle.
• the coating cell 6 preferably has guides for guiding the continuous product 12, which are designed in such a way that a uniform distance between the anodes 26 arranged in the coating cell and the continuous product 12 to be coated is ensured.
• the coating cell has an overflow and an inlet for the electrolyte.
• the guides in the coating cells consist of a carrier 28 made of insulating material, which is drilled through in the middle, with bushings 27 being arranged in the through-hole, which can only be inserted on one side and preferably consist of ceramic material and for easier interchangeability for continuous products of various types Diameter are divided.
• FIG. 4 shows an illustration of the contacting cell 5.
• FIG. 4a shows an enlargement of the contacting area as a side view.
• FIG. 4b shows a perspective view of the contacting cell 5.
• the continuous product is identified by the number 12. This is passed between a metal roller 29 which is under cathodic voltage and a non-conductive ceramic tensioning roller 30, the notches in the metal rollers being designated by the number 32 for better guidance of the continuous product 12.
• the number 33 is the holding elements for the metal rollers and the ceramic tensioning rollers designated.
• FIG. 4a shows an enlarged section of the contacting area.
• the number 29 shows the metal roller, number 31 a bronze socket for power supply, number 12 the continuous product and number 30 are the ceramic tension rollers. These are used to set the preload via springs or set screws for the continuous product.
• the contacting cell 5 is preferably designed such that a metal roller or a sliding contact is arranged in it, via which the continuous product is connected cathodically.
• one or more ceramic tensioning rollers can be arranged in the contacting cell for setting the pretension.
• the metal roll has a notch over which the continuous product is passed.
• an overflow is also preferably arranged so that urgent electrolytes can be discharged from the electrolytic cell into a collection system.
• FIG. 5 shows a view of the coating cell 6, the contacting cell 5 and the rinsing units 3.
• FIG. 5a shows the top view of these cells
• FIG. 5b shows a side view.
• the flushing units 3 are designed in a similar manner to the lock systems in FIG. 2 described above. They also have an overflow and adjacent overflow chambers, the middle chamber being filled with liquid in each case. This can run through the non-tight guides into the neighboring chambers and is collected by appropriate processes and returned to the rinsing chambers.
• the contacting cells are described with the number 5. These are preferably adjacent to the coating cells 6 and filled with electrolyte.
• the number 6 shows the coating cells with the anodes 26 and the supports 28 made of insulating material with the ceramic bushings 29 therein for guiding the continuous products 12 in the coating cells.
• the coating cells are also filled with electrolyte and have an overflow, an outlet and an inlet through which the respective electrolyte liquids can be circulated, cleaned and returned.
• the device according to the invention has considerable advantages over previously known devices for the metallization of continuous products.
• the wire can thus be stably positioned via non-conductive tubes and roller guides within the device, but especially in the electrical field of the coating cell 6. This stable guidance makes it possible to pass several parallel strands of continuous products, for example several wires, even in a vertical arrangement through the device without causing undesired ones electrical contacts and a uniform distance to the anode is guaranteed.
• the lock systems 1, rinsing units 3 and contacting cells 5 constructed as flooding chambers make electrical inter-contacting possible outside the effective range of the anode material, the continuous product remaining in the electrolyte.
• the transmission of the electrical energy in the contacting cells 5 can take place both via sliding contacts in the form of flexible contact pins, which are spring-loaded, as well as via spring-loaded contact rollers.
• the special storage of the continuous product in the contacting cell 5, as well as the guides in the coating cell 6, make it possible to drive different diameters of continuous products.
• the preferred deflection units 4 make it possible to pass the continuous products through several parallel coating cells and thus to enable high throughput speeds in relatively short systems.
• the continuous product can remain in the chambers without an overreaction on the surface, such as over-pickling or one-sided over-coating, since the reaction media are stored in the intermediate containers outside the reaction spaces while maintaining the inert atmosphere in the system . It is also advantageous that the anode material can be exchanged at a standstill without removing the material to be coated from the system.
• the method and the device according to the invention it is possible for the first time to coat continuous products with metals, in particular aluminum, in an industrial process and a corresponding device.
• the method according to the invention and the device thus replace the previously exclusively used methods of hot-dip aluminizing, hot-dip galvanizing and electrolytic coating in aqueous media.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Electroplating Methods And Accessories (AREA)
• Wire Processing (AREA)
• Electrolytic Production Of Metals (AREA)
• Manufacturing Of Printed Wiring (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=7827072

Family Applications (1)

Country Status (9)

Families Citing this family (4)

Family Cites Families (11)

• 1997
  • 1997-04-19 DE DE19716493A patent/DE19716493C2/de not_active Expired - Lifetime
• 1998
  • 1998-04-15 EP EP98922715A patent/EP0975826B1/fr not_active Expired - Lifetime
  • 1998-04-15 WO PCT/EP1998/002196 patent/WO1998048081A2/fr not_active Ceased
  • 1998-04-15 AT AT98922715T patent/ATE220130T1/de not_active IP Right Cessation
  • 1998-04-15 CA CA002287179A patent/CA2287179C/fr not_active Expired - Fee Related
  • 1998-04-15 DE DE59804675T patent/DE59804675D1/de not_active Expired - Lifetime
  • 1998-04-15 JP JP54495798A patent/JP4411397B2/ja not_active Expired - Fee Related
  • 1998-04-15 AU AU75257/98A patent/AU7525798A/en not_active Abandoned
  • 1998-04-15 US US09/403,430 patent/US6340422B1/en not_active Expired - Fee Related
  • 1998-04-20 ZA ZA983275A patent/ZA983275B/xx unknown

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events