US3300400A - Electrocoating process with terminal showering step - Google Patents

Electrocoating process with terminal showering step Download PDF

Info

Publication number
US3300400A
US3300400A US291625A US29162563A US3300400A US 3300400 A US3300400 A US 3300400A US 291625 A US291625 A US 291625A US 29162563 A US29162563 A US 29162563A US 3300400 A US3300400 A US 3300400A
Authority
US
United States
Prior art keywords
electrode
bath
coating
shower
contact
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.)
Expired - Lifetime
Application number
US291625A
Other languages
English (en)
Inventor
Gilbert L Burnside
Leopold A Madejczyk
Gordon G Strosberg
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ford Motor Co
Original Assignee
Ford Motor Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Ford Motor Co filed Critical Ford Motor Co
Priority to US291625A priority Critical patent/US3300400A/en
Priority to DEF43035A priority patent/DE1258769B/de
Priority to NL646407320A priority patent/NL142093B/xx
Priority to GB26757/64A priority patent/GB1019108A/en
Priority to FR979981A priority patent/FR1400797A/fr
Priority to SE7971/64A priority patent/SE308850B/xx
Priority to CH860364A priority patent/CH412509A/fr
Priority to BE650007D priority patent/BE650007A/xx
Application granted granted Critical
Publication of US3300400A publication Critical patent/US3300400A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D13/00—Electrophoretic coating characterised by the process
    • C25D13/22—Servicing or operating apparatus or multistep processes

Definitions

  • This invention relates to an improvement in continuous coating processes wherein a conductive substrate is coated with an organic film-forming material by electrically induced deposition from an aqueous bath.
  • this invention relates to method and means for promoting coating uniformity in a continuous or intermittently continuous electropainting process wherein a substantially water insoluble coating is deposited upon a moving workpiece in contact with an aqueous bath. More particularly, this invention is concerned with surface irregularities in an electrocoat which result from leaving a workpiece temporarily stationary and partially submerged in the coating bath.
  • Objects to be coated are suspended from and transported by an overhead conveyor which, with suitable connecting devices, is constructed and arranged such that the suspended workpieces successively enter the aqueous bath for coating and are withdrawn for further processing such as baking, sanding, finish coating, etc. While being coated the object or workpiece is positively charged and a direct current flow of electrical energy is provided between the workpiece and a negative and grounded coating tank or other electrode. In normal operation the conveyor line will stop at irregular intervals for various periods of time. Objects entering or leaving the bath will frequently come to rest with a lower portion of the object below the surface of the aqueous bath and an' upper portion exposed to the atmosphere. It has been found that such stoppages leave deleterious water line irregularities in the coating if provision is not made to avoid their formation or to effect their immediate removal or overcoat. Subsequent removal necessitates refinishing.
  • Organic coating materials which may be used in the bath include but not by way of limitation alkyd resins, acrylate resins, phenol-formaldehyde resins and various carboxylic acid resins or mixtures of the foregoing with each other or other film-forming materials including binding agents and extenders conventionally employed with water based paints.
  • Such materials may include or be employed with other organic monomers an-d/ or polymers including but not by way of limitation hydrocarbons and oxygen substituted hydrocarbons such as ethylene glycol, propylene glycol, glycerol, carbitol, methanol and various carboxylic acids, ethers, aldehydes and ketones.
  • the film-forming material may include or be employed with pigments, dyes, drying oils, etc. and may be dispersed as a colloid, emulsion or emulsoid.
  • the organic coating material is dispersed in the bath with the aid of a conventional dispersing agent.
  • a conventional dispersing agent include water soluble ammonium and basic amine salts, polymeric amines, etc. Such materials are described at length in US. Patent 2,530,366 to A. G. Gray and elsewhere in the literature.
  • FIGURE 1 is a schematic drawingdepicting one embodiment of electrocoating apparatus suitable for use with the coating methods herein described, and,
  • FIGURE 2 is a schematic, partial cross-sectional view 7 of the apparatus shown in FIGURE 1 illustrating the shower equipment in operation.
  • a chemically resistant tank 11 contains an aqueous coating bath 13 and serves as a negative electrode or cathode in the coating process.
  • Tank 11 is electrically connected to DC. power source 17 via conductor 15.
  • An article towbe coated 19, eg an automobile body, is shown suspended from an endless conveyor 23 by a hanger 21.
  • Conveyor 23 may be of the electrically powered, chain driven variety.
  • Hanger 21 includes insulator 25 which insulates article 19 from the grounded conveyor.
  • Contact plate or brush 27 is attached to and in electrical connection with hanger 21.
  • Article 19 is shown approaching bath 13 and in electrical connection with bus bar 29 which in turn is in electrical connection with DC. power source 17 via conductor 31.
  • Tank 11 is also equipped with recycle shower apparatus one unit of which is here illustrated by pump support 35, pump 37, housing 39, housing support 41, upright conduit 43, lower shower head 47, and upper shower head 51.
  • an inlet conduit 33 places pump 37 in fluid communication with the bath in tank 11.
  • Outlet conduits 45 and 49 respectively place shower heads 47 and 51 in fluid communication with conduit 43.
  • a second shower unit comprising inlet conduit 63, pump support 65, pump 67, housing 69, housing support 71, upright conduit 73, outlet conduit 75, lower shower head 77, outlet conduit 79 and upper shower head 81 is shown oppositely positioned from the previously described shower unit and near the end of tank 11 from which the coated objects are withdrawn.
  • Pumps 37 and 67 are conventional constant pressure pumps and are conected to a conventional power source, not shown.
  • each of the shower heads is in electrical connection withtank 11 and hence forms a portion of the negative electrode system. It will be understood that the shower units here shown may be arranged and multiplied as desired in accordance with the coating process with which the same are employed.
  • the workpiece 19 is here shown emerging from the bath under a constant shower of bath material drawn from the bath through the aforedescribed shower apparatus.
  • the positive charge imparted to the workpiece while submerged in the coating bath is maintained while the workpiece passes through the shower which is preferably of small or discrete droplets. It is within the scope of this invention to terminate the shower activity when the conveyor is stopped or, in the alternative, to maintain such activity independent of the movement of the conveyor.
  • the coating of the submerged object within the bath will ordinarily be carried out at a potential in the range of about 500 to 1000, preferably to 500, volts.
  • the droplet or particle size and intensity of the shower or spray through which the object emerges will be varied in accordance with the particular system taking into account the individual coating bath, its properties, and its composition. An effective amount of spray can be readily determined in each instance by routine testing and adjustment.
  • a method of coating which comprises transporting an electrically conductive object through an aqueous bath having organic film-forming material dispersed therein and a first charged electrode in contact therewith, imparting an electrical charge to said object so that said object serves while in contact with said bath as a second electrode and is of opposite polarity to said first electrode, and providing a flow of electrical energy between said first electrode and said second electrode and through said bath until a substantially water insoluble coating of said organic material is deposited upon said second electrode, the improvement which comprises showering said second electrode with said aqueous bath material as said second electrode emerges from said bath and maintaining said shower until said second electrode is out of contact with said bath.
  • a method of coating which comprises transporting an electrically conductive object through an aqueous bath having organic film-forming material intimately dis persed therein and a first and negatively charged electrode in contact therewith, imparting an electrical charge to said object so that said object serves while in contact with said bath as a second electrode and is of opposite polarity to said first electrode, and maintaining a How of electrical energy between said first electrode and said second electrode until 'a'substanti'ally water insoluble coating of said organic material is deposited upon said second electrode, the improvement which comprises maintaining said electrical charge on said second electrode as the same emerges from said coating bath and showering said second electrode with discrete droplets of said aqueous bath issuing from a third electrode of the same polarity as said first electrode until essentially all of said second electrode is out of contact with said bath.
  • a method of coating which comprises transporting an electrically conductive object through an aqueous bath having organic film-forming material intimately dispersed therein and a charged cathode in contact therewith, imparting an electrical charge to said object so that said object serves as the anode of a coating cell while in contact with said bath, and maintaining a flow of electrical energy between said cathode and said anode until a substantially water insoluble coating material is deposited upon said anode
  • the improvement which comprises providing above the surface of said bath a spray of said bath material issuing from a third electrode of the same polarity as said cathode and passing the charged anode through said spray as it emerges from said bath material.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Electrostatic Spraying Apparatus (AREA)
  • Paints Or Removers (AREA)
US291625A 1963-07-01 1963-07-01 Electrocoating process with terminal showering step Expired - Lifetime US3300400A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
US291625A US3300400A (en) 1963-07-01 1963-07-01 Electrocoating process with terminal showering step
DEF43035A DE1258769B (de) 1963-07-01 1964-06-01 Verfahren und Vorrichtung zum elektrischen UEberziehen von Gegenstaenden mit einem organischen Filmbildner
NL646407320A NL142093B (nl) 1963-07-01 1964-06-26 Werkwijze voor het bekleden van een elektrisch geleidend voorwerp, inrichting voor het ten uitvoer leggen van deze werkwijze en voorwerp bekleed onder toepassing van deze werkwijze.
FR979981A FR1400797A (fr) 1963-07-01 1964-06-29 Procédé perfectionné de revêtement et appareil en comportant application
GB26757/64A GB1019108A (en) 1963-07-01 1964-06-29 Method of and apparatus for coating an article by electrophoresis
SE7971/64A SE308850B (xx) 1963-07-01 1964-06-30
CH860364A CH412509A (fr) 1963-07-01 1964-07-01 Procédé de revêtement d'un objet électriquement conducteur et appareil pour sa mise en oeuvre
BE650007D BE650007A (xx) 1963-07-01 1964-07-01

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US291625A US3300400A (en) 1963-07-01 1963-07-01 Electrocoating process with terminal showering step

Publications (1)

Publication Number Publication Date
US3300400A true US3300400A (en) 1967-01-24

Family

ID=23121088

Family Applications (1)

Application Number Title Priority Date Filing Date
US291625A Expired - Lifetime US3300400A (en) 1963-07-01 1963-07-01 Electrocoating process with terminal showering step

Country Status (7)

Country Link
US (1) US3300400A (xx)
BE (1) BE650007A (xx)
CH (1) CH412509A (xx)
DE (1) DE1258769B (xx)
GB (1) GB1019108A (xx)
NL (1) NL142093B (xx)
SE (1) SE308850B (xx)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4663014A (en) * 1986-01-02 1987-05-05 I. Jay Bassett Electrodeposition coating apparatus
US4755273A (en) * 1986-01-02 1988-07-05 Bassett I Jay Cover for coating tanks
US5110440A (en) * 1988-02-16 1992-05-05 Elcoat Systems, Inc. Roll immersion system

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1590601A (en) * 1920-03-11 1926-06-29 Taylor Lab Inc Treatment of organic material
US1897902A (en) * 1927-03-14 1933-02-14 Harsanyi Eugene Method of coating radiant bodies
US1911808A (en) * 1930-11-28 1933-05-30 Delaware Lackawanna & Western Method of coloring coal
US2753298A (en) * 1952-10-02 1956-07-03 Pittsburgh Plate Glass Co Method and apparatus for continuous plating

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1590601A (en) * 1920-03-11 1926-06-29 Taylor Lab Inc Treatment of organic material
US1897902A (en) * 1927-03-14 1933-02-14 Harsanyi Eugene Method of coating radiant bodies
US1911808A (en) * 1930-11-28 1933-05-30 Delaware Lackawanna & Western Method of coloring coal
US2753298A (en) * 1952-10-02 1956-07-03 Pittsburgh Plate Glass Co Method and apparatus for continuous plating

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4663014A (en) * 1986-01-02 1987-05-05 I. Jay Bassett Electrodeposition coating apparatus
US4755273A (en) * 1986-01-02 1988-07-05 Bassett I Jay Cover for coating tanks
US5110440A (en) * 1988-02-16 1992-05-05 Elcoat Systems, Inc. Roll immersion system

Also Published As

Publication number Publication date
DE1258769B (de) 1968-01-11
SE308850B (xx) 1969-02-24
NL6407320A (xx) 1965-01-04
BE650007A (xx) 1964-11-03
NL142093B (nl) 1974-05-15
GB1019108A (en) 1966-02-02
CH412509A (fr) 1966-04-30

Similar Documents

Publication Publication Date Title
US3304250A (en) Continuous electrocoating process utilizing electrodialysis to control the bath composition
US3355374A (en) Method of electrocoating with variation of electrical inducement
US4529492A (en) Process for the coating of hollow bodies open on one side
US3355373A (en) Method for adjusting the bath composition in a continuous electrodeposition process
US3399128A (en) Electrodeposition process and apparatus having a movable conduit electrode
US3300400A (en) Electrocoating process with terminal showering step
GB1180731A (en) Electrodeposition Coating Process and Apparatus
US3399126A (en) Electrodeposition process and apparatus having conduit electrodes
US3962060A (en) Continuous electrodeposition of coating material on metal sheet stock
GB1192804A (en) Improved method and apparatus for Electrically Induced Deposition of Paint on Conductors
US3325390A (en) Method and apparatus for electrocoating using an auxiliary electrode
US3492213A (en) Method for electrodeposition coating including a preimmersion deposition step
US5264096A (en) Process for anodic or cathodic electrocoating of strip or profile material
DE2063160C3 (de) Verfahren zur elektrophoretischen Abscheidung von Anstrichen
US3361658A (en) Method of electrophoretic surface coating
US3388052A (en) Method and apparatus for automatically checking electrical condition of workpieces prior to electrocoating process
US3444064A (en) Method for improving operational stability of electrocoating bath
US3444065A (en) Method for electrodeposition of paint
CN113584557B (zh) 一种铝型材喷涂设备及其喷涂方法
Brewer Electrophoretic painting
US3471389A (en) Electrocoating process wherein the initial amperage surge is controlled
US3418233A (en) Apparatus for electrocoating using an auxiliary electrode
US3682806A (en) Cathodic treatment of an electrocoating bath
US3630870A (en) Base concentration control in electrodeposition of paint
US3305467A (en) Electrocoating feed control process and apparatus