Classifications

• • 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
  • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
  • C23G5/00—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N3/00—Preparing for use and conserving printing surfaces
  • B41N3/03—Chemical or electrical pretreatment

Definitions

• the present invention relates to the degreasing of sheetlike rolled aluminum products, in particular aluminum strips or webs of aluminum foil, and also sheets or cuts of rolled aluminum.
• sheetlike rolled aluminum products in particular aluminum strips or webs of aluminum foil, and also sheets or cuts of rolled aluminum.
• the invention will be described in the following particularly with reference to aluminum strips, but the statements made herein apply also to thinner or thicker aluminum webs and to cuts of all thicknesses.
• Equivalent to rolled aluminum products, in the sense of the present invention are rolled products of other nonferrous metals, such as e.g., rolled products of aluminum alloys.
• the simplest method is by annealing, so that any adhering grease is evaporated or burned. During this heat treatment, the aluminum becomes soft, so that this method can not be used in those cases where the aluminum is to be used in a hard rolled condition.
• the traces of grease are removed by means of solvents, e.g. aliphatic chlorinated hydrocarbons, by passing the aluminum strips or sheets through apparatus provided for this purpose.
• solvents e.g. aliphatic chlorinated hydrocarbons
• Still another method is a treatment with chemical means, e.g., aqueous alkaline substances, which causes the residual rolling grease to be partially dissolved in the form of soaps, any unsaponifiable components being removed at the same time.
• Oxidative methods are also known, wherein aluminum objects are treated, e.g., with chromosulfuric acid or salt melts.
• the aluminum surface is freed from greasy impurities by mechanical treatment, e.g., brushing or grinding.
• This method is employed, e.g.,for delustering aluminum strips and foils. It cleans the aluminum surface very thoroughly and it is, therefore, also used for cleaning aluminum strips or foils which are to be used in lithography for the preparation of printing plates.
• the requirements with regard to the purity of the surfaces are very high even for low-grade printing plates; for printing plates of very good quality they are extremely high.
• the aluminum must be in a hard, rolled condition.
• the present invention provides a process for degreasing sheetlike rolled aluminum products which results in a more satisfactory degreasing than the methods hitherto used.
• the process of the present invention includes the known cleaning of aluminum surfaces by mechanical means and removal of the detached particles by blowing with air, but it is performed in a novel manner. It has been found that a noticeably better degreasing is achieved by adding water vapor to the air supplied during the mechanical degreasing process, e.g., by brushing or grinding, or by blowing with water vapor instead of air.
• the effectiveness of the new method becomes apparent when using the aluminum strips degreased by the new process. For instance, if printing plates are prepared therefrom, a successful treatment becomes apparent in a reduction or, optimally, the complete absence of defects in the printing plate, i.e., defects which otherwise would accept printing ink and thus print and which would have to be removed by correction if the printing plate is to yield flawless prints.
• the degree of purity of the cleaned .aluminum strip also can be judged more easily and quickly by first wiping the surface of a sample with a molar phosphoric acid solution and then inking it up with a protective ink, as is customary in lithography for newly prepared offset printing plates in order to provide them with a coating which protects the printing image on the offset plate against wear during storage and handling.
• a protective ink as is customary in lithography for newly prepared offset printing plates in order to provide them with a coating which protects the printing image on the offset plate against wear during storage and handling.
• EXAMPLE A cold-rolled aluminum strip was washed with gasoline, so that the greater part of the grease adhering thereto from the rolling process was removed. Thereafter, the strip was cleaned by brushing it in an atmosphere of 50 percent relative humidity with the dust brushed ofi being removed by blowing with air. A sample of the cleaned strip was inked up with protective ink. Numerous spots colored by the protective ink became visible On the sample sheet. They indicated the presence of an equal number of grease spots.
• blowing in was performed with air humidified to a relative humidity of percent.
• a sample taken during this test showed only a small number of defects, but more than a sample taken from a strip treated 'with air of percent relative humidity.
• a process for degreasing a rolled aluminum product which comprises mechanically removing grease from the surface of the aluminum and blowing a stream of air having a relative humidity of at least 60 percent onto the surface.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Photoreceptors In Electrophotography (AREA)
• Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
• Printing Plates And Materials Therefor (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=7229874

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (6)

Citations (2)

• 1966
  • 1966-12-23 DE DE19661621607 patent/DE1621607A1/de active Pending
• 1967
  • 1967-12-13 NL NL6716957A patent/NL6716957A/xx unknown
  • 1967-12-20 BE BE708302D patent/BE708302A/xx unknown
  • 1967-12-20 AT AT1153367A patent/AT269592B/de active
  • 1967-12-21 US US692268A patent/US3526546A/en not_active Expired - Lifetime
  • 1967-12-21 GB GB58179/67A patent/GB1200500A/en not_active Expired
  • 1967-12-21 FR FR1548999D patent/FR1548999A/fr not_active Expired

Patent Citations (2)

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