Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
  • C25F1/00—Electrolytic cleaning, degreasing, pickling or descaling
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
  • C23C2/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
  • C23C2/024—Pretreatment of the material to be coated, e.g. for coating on selected surface areas by cleaning or etching
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
  • C25F1/00—Electrolytic cleaning, degreasing, pickling or descaling
  • C25F1/02—Pickling; Descaling
  • C25F1/04—Pickling; Descaling in solution
  • C25F1/06—Iron or steel

Definitions

• a further object of this invention is to provide a cleaning treatment which will provide improved adhesion of subsequent coatings.
• Another object is to provide a cleaning process which eliminates the necessity for additional cleaning steps employed to compensate for inadequate prior art electroalkaline cleaning.
• the effectiveness of the cleaning operation was determined by the degree of adhesion which was obtained in a subsequent electroless plating with CuSO After the copper plating, the amount of copper which could be rubbed off the test sample was noted and was rated on a l to 4 basis, with 4 representing total vadherence and l representing poor adherence (i.e. large amount of plating rubbed Ofl).
• high current density electro-cleaning provides a substantial improvement, as evidencedby the enhanced adherence of the copper plate.
• high current densities are advantageous in two other respects; l they permit higher operating speeds and shorter cleaning cells, due to the considerably faster removal which is achieved, and (2) they are more etficient than low current densities, i.e., they provide equivalent cleaning with less energy expended.
• the degree of removal achieved at 40 A/in for 0.4 seconds (16 coul/in) is'at least as good as the results obtained when the prior art practice is employed, i.e. applying 1 A/in for 60 seconds (60 coullin or a ratio of energy expended of almost 1 to 4.
• electrolyte is a'mixture containing 60 to NaOH or an equivalent high conductivity alkali hydroxide, 5 to 30% Na P,O, and 5 to 25% Na Co This mixture (to which a non-foaming surface active agent may be added to promote wetting of the strand) is dissolved in water to a concentration of 10 to 20% by weight and during operation is maintained within a temperature range of to 210 F.
• Other well-known builders may be substituted for the above components, tag.
• the sesquicarbonate for the carbonate and trisodium phosphate or the tripolyphosphate for the tetrasodium pyrophosphate It is, of course, essential that the solution possess sufficient conductivity to permit electrolyzation with a current density of at least 30 amps/in.
• the electric current is introduced to the strand via the electrolyte.
• a preferred apparatus for the instant process is that described in US. Pat. No. 3,338,809, in which the electrodes surround .the strand without actually contacting it. in employing the contact time of greater than 2.5 seconds is less desirable for economic considerations and does not appear to provide any enhanced cleaning. Therefore, in order to attain this minimum immersion time as line speed is increased, it will be necessary to likewise increase the number of cell chambers.
• the polarity is such that the strand will be anodic in the final chamber, thereby avoiding the danger of electrolyte contaminates plating out on the treated strand.
• a method for the cleaning of ferrous strands and the a removal of lubricants therefrom which comprises electrolyzing said strand with a direct current at a current density of 30 I to tSO ampsIin for an immersion time of at least 0.4 seconds, in
• lubricants are selected from the group consisting of oils, greases and watersoluble soaps and carriers.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Electrochemistry (AREA)
• Mechanical Engineering (AREA)
• Lubricants (AREA)
• Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
• Electroplating Methods And Accessories (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=21853849

Family Applications (1)

Country Status (6)

Cited By (2)

Families Citing this family (1)

Citations (5)

• 1970
  • 1970-04-20 US US30358A patent/US3668090A/en not_active Expired - Lifetime
• 1971
  • 1971-04-05 CA CA109,628A patent/CA984783A/en not_active Expired
  • 1971-04-14 BE BE765744A patent/BE765744A/xx unknown
  • 1971-04-19 GB GB26668/71A patent/GB1294054A/en not_active Expired
  • 1971-04-19 FR FR7113761A patent/FR2086193B1/fr not_active Expired
  • 1971-04-20 DE DE19712119086 patent/DE2119086A1/de active Pending

Patent Citations (5)

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