U.S. patent application number 10/274868 was filed with the patent office on 2003-03-06 for method for manufacturing front sheet and microwave oven having the same.
This patent application is currently assigned to LG Electronics Inc.. Invention is credited to Lee, Jong-Woog, Lee, Kwan-Ho.
Application Number | 20030045212 10/274868 |
Document ID | / |
Family ID | 19705145 |
Filed Date | 2003-03-06 |
United States Patent
Application |
20030045212 |
Kind Code |
A1 |
Lee, Kwan-Ho ; et
al. |
March 6, 2003 |
Method for manufacturing front sheet and microwave oven having the
same
Abstract
The present invention relates to a front sheet of a microwave
oven and a method for manufacturing the front sheet. The method for
manufacturing the front sheet of the microwave oven according to
the present invention comprises a first process including a
chemical polishing process of removing foreign materials from and
polishing a surface of an aluminum sheet so as to give a
predetermined luster thereto; a process of forming a porous anodic
oxide film onto the surface of the aluminum sheet; a process of
dipping the aluminum sheet into a solution containing a dye and
penetrating the dye into a porous film of the anodic oxide film;
and a process of sealing the porous film into which the dye has
been penetrated. The microwave oven according to the present
invention includes a colored front sheet manufactured by anodizing
and dyeing the surface of the aluminum sheet and attached to a
front face of a door portion or a control panel portion of the
microwave oven.
Inventors: |
Lee, Kwan-Ho; (Changwon
Gyeongnam, KR) ; Lee, Jong-Woog; (Changwon Gyeongnam,
KR) |
Correspondence
Address: |
FLESHNER & KIM, LLP
P.O. Box 221200
Chantilly
VA
20153-1200
US
|
Assignee: |
LG Electronics Inc.
|
Family ID: |
19705145 |
Appl. No.: |
10/274868 |
Filed: |
October 22, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10274868 |
Oct 22, 2002 |
|
|
|
09832957 |
Apr 12, 2001 |
|
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Current U.S.
Class: |
451/56 ;
451/57 |
Current CPC
Class: |
C25D 11/243 20130101;
C25D 11/18 20130101; H05B 6/6426 20130101; C25D 11/16 20130101;
C25D 11/246 20130101 |
Class at
Publication: |
451/56 ;
451/57 |
International
Class: |
B24B 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 31, 2001 |
KR |
2001-4575 |
Claims
What is claimed is:
1. A method for manufacturing a front sheet of a microwave oven,
comprising: a first process including a chemical polishing process
of removing foreign materials from and polishing a surface of an
aluminum sheet so as to give a predetermined luster thereto; a
process of forming a porous anodic oxide film onto said surface of
said aluminum sheet; a process of dipping said aluminum sheet into
a solution containing a dye and penetrating said dye into a porous
film of said anodic oxide film; and a process of sealing said
porous film into which said dye is penetrated.
2. The method for manufacturing a front sheet of a microwave oven
as claimed in claim 1, further comprising a texture treatment
process of surface treating said aluminum sheet in order to give a
predetermined texture to said surface of said aluminum sheet prior
to said first process.
3. The method for manufacturing a front sheet of a microwave oven
as claimed in claim 1, wherein said first process comprises the
steps of removing organic contaminants from said surface by using
an organic solvent, and of polishing said surface of said aluminum
sheet by using a chemical solution containing phosphoric acid,
sulfuric acid and nitric acid.
4. The method for manufacturing a front sheet of a microwave oven
as claimed in claim 3, further comprising removing foreign
materials from said surface of said aluminum sheet by using an
alkaline solution.
5. A microwave oven, comprising: a colored front sheet manufactured
by anodizing and dyeing a surface of an aluminum sheet and attached
to a front face of a door portion or a control panel portion of
said microwave oven.
6. The microwave oven as claimed in claim 5, wherein said front
sheet is constructed to wrap around at least a portion of a front
side, opposite lateral sides, and upper and lower sides of said
door portion of said microwave oven.
7. The microwave oven as claimed in claim 5 or 6, wherein said
front sheet is attached to said front face by using an
adhesive.
8. The microwave oven as claimed in claim 5 or 6, wherein said
front sheet is attached by coupling mounting projections formed on
upper and lower portions of said door portion or said control panel
portion with mounting holes formed on said front sheet at positions
corresponding thereto, or by using an adhesive therebetween.
9. The microwave oven as claimed in claim 6, wherein edge portions,
where said front side joins with said lateral sides and said upper
and lower sides, respectively, are treated to have predetermined
rounded shapes.
Description
TECHNICAL FIELD
[0001] The present invention relates to a front sheet, and more
particularly, to a method for manufacturing a front sheet of a
microwave oven, which is capable of generating a new aesthetic
sense by making a desired color represented thereon by means of
aluminum material, and a microwave oven with the front sheet
attached thereto.
BACKGROUND ART
[0002] The front sheet of the microwave oven is a part attached to
a front portion of the microwave oven in order to wrap around a
front side of a door of the microwave oven or a control panel
adjacent to the door. Heretofore, a door panel or a control panel
made from synthetic resin material has been directly used, as it
is, for such a front sheet of the microwave oven, or the front
sheet has been manufactured from a metallic material (e.g.,
stainless steel) having a simple metallic texture.
[0003] However, the front sheet of the microwave oven made of
synthetic resin material may be varied to a certain extent in view
of colors, designs, etc., but it is still has a shortcoming that
due to material limitation of the synthetic resin material, further
variability of the design or texture cannot be provided. In
addition, the front sheet of the microwave oven may have another
shortcoming that it cannot satisfy current trends that recent
designs of the electric home appliances pursue high quality
exteriors.
[0004] Furthermore, the front sheet of the microwave oven may be
also made of stainless steel, like the other electric home
appliances. However, the front sheet of the microwave oven made
from the stainless steel has an advantage of satisfying the
metallic texture and high quality trends, but it still has a
difficulty in obtaining a desired color thereof. That is, the
coloration of the desired color onto the panel made of the
stainless steel material is practically undesirable since it should
be subjected to substantially high-priced treatment processes owing
to a nature of the material. Therefore, unit cost of production for
the front sheet increases.
SUMMARY OF INVENTION
[0005] The object of the present invention is to provide a front
sheet of a microwave oven that can have various colors as well as a
new metallic texture.
[0006] In order to achieve the above object, a method for
manufacturing a front sheet of a microwave oven according to the
present invention comprises a first process including a chemical
polishing process of removing foreign materials from and polishing
a surface of an aluminum sheet so as to give a constant luster
thereto, a process of forming a porous anodic oxide film onto the
surface of the aluminum sheet, a process of dipping the aluminum
sheet into a dye solution containing a dye and of penetrating the
dye into a porous film of the anodic oxide film, and a process of
sealing the porous film into which the dye has been penetrated.
[0007] A microwave oven according to the present invention
comprises a colored front sheet manufactured by anodizing and
dyeing a surface of an aluminum sheet and attached to a front side
of a door portion or a control panel portion of the microwave
oven.
BRIEF DESCRIPTION OF DRAWINGS
[0008] FIG. 1 is an illustrative perspective view of a microwave
oven according to the present invention.
[0009] FIG. 2 is a flowchart illustrating a series of processes for
manufacturing a front sheet according to the present invention.
[0010] FIG. 3 is a sectional view taken along a line A-A of FIG. 1
in a condition that a front sheet is attached to a microwave
oven.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] Hereinafter, preferred embodiments of the present invention
will be explained in detail with reference to the drawings.
[0012] As shown in FIG. 1, a front sheet of a microwave oven
according to the present invention includes a front sheet 7 for a
door panel 1 which is fixed to a front side of the door panel of
the microwave oven, and a front sheet 5 for a control panel 3 which
is fixed in order to wrap around peripheral portions of the control
panel 3 installed to a side of the door panel 1.
[0013] Such a front sheet according to the present invention is
made of an aluminum plate. Hereinafter, processes for manufacturing
the front sheet according to the present invention using the
aluminum plate (hereinafter, referred to as "aluminum sheet") will
be described one after another with reference to FIG. 2.
[0014] First, a thin aluminum sheet is prepared and then a process
of manufacturing the aluminum sheet into a shape of the front sheet
is performed (Step 102). Indeed, this step 102 means that the
aluminum sheet is completely manufactured in the shape of the front
sheet 7 for the door panel or the front sheet 5 for the control
panel as shown in FIG. 1.
[0015] After the aluminum sheet is completely manufactured to have
the shape of the front sheet as mentioned above, a process of
treating a surface texture of the front sheet is accomplished in a
step 104. Such a texture treatment process is optional, and it
means a surface treatment process for imparting a predetermined
texture such as a hair line, etc. to the surface of the aluminum
sheet. For example, a pattern such a hair is manufactured onto the
aluminum sheet surface using a metallic brush, or the surface of
the aluminum sheet is processed to have a predetermined texture by
means of a sand blasting method.
[0016] After such optional step 104 is completed, a process of
degreasing the surface of the aluminum sheet is performed in a step
106. This process is a process for removing fat ingredients stained
on the surface of the aluminum sheet, that is, a process for
removing organic pollutants or contaminants with which the surface
of the aluminum sheet is stained, by means of organic solvents.
After the degreasing step is completed in a manner mentioned above,
plural washing processes are performed in a step 108. The washing
process is a process of cleaning up the organic solvents and the
pollutants remained on the surface during the degreasing step. For
example, the surface is cleaned up repeatedly by means of flowing
water.
[0017] After the washing step is completed, a chemical polishing
process is performed in a step 110. The chemical polishing process
is a process for chemically polishing the surface regularly in
order to impart surface luster to the aluminum sheet. The chemical
polishing process may be performed by simply dipping the front
sheet of the present invention into various chemical solutions.
Further, according to an embodiment of the present invention, the
chemical polishing process may be performed by dipping the aluminum
sheet into an acid solution composed of 90% phosphoric acid, 3%
sulfuric acid and 7% nitric acid during a predetermined period of
time (e.g., 3 minutes). In this case, it is preferable that the
temperature of the acid solution be set to be an appropriate
temperature most suitable to the chemical polishing. In the
embodiment employing the acid solution, the most appropriate
temperature of the acid solution is about 110.degree..degree. C.
Then, the surface of the aluminum sheet may have a predetermined
luster after completion of the chemical polishing.
[0018] Further processes for removing foreign materials from the
surface of the aluminum sheet, for example, the process for
cleaning up the surface after removing the foreign materials from
the surfaces by means of an alkali such as sodium hydroxide, etc.
may be included between the steps 108 and 110. After completion of
the chemical polishing, a washing process is again performed in a
step 112. After this washing process is completed, acid treatment
for the surface of the aluminum sheet is performed in a step 114.
The acid treatment process is a process for perfectly removing
impurities contained on the surface of the aluminum sheet. For
example, the aluminum sheet cannot have a pure surface since white
spots may be created thereon due to various impurities contained
therein. Therefore, the treatment to be described below can be more
perfectly performed by completely removing the impurities adhered
to the surface of the aluminum sheet.
[0019] And then, after such acid treatment is completed, an
additional washing process (Step 116) is again performed.
[0020] The foregoing processes correspond substantially to
pretreatment. The pretreatment is processes for more efficiently
performing the formation of an oxide film onto the surface of the
aluminum sheet by anodic oxidation and the dyeing of the aluminum
sheet surface, as described later. Thus, after the pretreatment up
to the step 116 is completed, an electrolysis process of forming
the anodic oxide film onto the surface of the aluminum sheet is
performed in a step 118. The formation of the anodic oxide film is
performed by the anodic oxidation. More specifically, the anodic
oxidation is performed in a manner that the aluminum sheet is
dipped into an electric furnace filled with an electrolytic
solution comprised of 80% water and 20% sulfuric acid, and that a
positive electrode and a negative electrode are applied to the
aluminum sheet and the electric furnace, respectively. And, at this
time, it is most preferred that the electrolytic solution be
maintained at a temperature (e.g., 24.degree..degree. C. to
27.degree..degree. C.) where the anodic oxidation can be occurred
most actively.
[0021] In the anodic oxidation method, if aluminum is subject to
the anodic oxidation in the acid solution such as sulfuric acid,
chromic acid, phosphoric acid, etc., a porous oxide film is
actually formed on the aluminum surface. The thickness of the
porous oxide film is determined depending on the parameters such as
time duration of electrolysis, electric current density, etc. As
the time duration of electrolysis is prolonged and the current
density is raised, the porous oxide film becomes thicker. That is,
the porous oxide film grows in proportion to an energizing quantity
of the electric current. In general, as the temperature of
electrolytic solution becomes low, growth of the oxide film is
better and the oxide film thus formed is harder. As the temperature
of electrolytic solution becomes high, the thinner and smoother
oxide film is formed. Therefore, if the electric current is applied
to the aluminum sheet as a positive electrode, the surface of the
aluminum sheet is oxidized by oxygen generated from the positive
electrode and then the aluminum oxide film, which is substantially
a very fine porous film, is formed thereon. Further, such anodic
oxide film substantially has a high hardness and has very superior
characteristics in view of wear resistance and aesthetic sense.
Furthermore, in the process of forming the anodic oxide film, more
beautiful and brilliant film can be obtained, as the purity of the
aluminum becomes higher. To this end, the foregoing pretreatment
including the step 114 should be performed.
[0022] If the formation of anodic oxide film onto the surface of
the aluminum sheet is completed by means of the foregoing
electrolysis process, another washing process is again performed in
a step 120.
[0023] After the washing process is completed, a process of dyeing
the surface of the aluminum sheet is performed in a step 122. The
dyeing process of the surface of the aluminum sheet will be
accomplished by penetrating a dye into fine pores formed on the
porous aluminum sheet surface as mentioned above. Further, as an
example, a dyeing method made by a dipping process may be used. For
example, by dipping the aluminum sheet, which is obtained from the
foregoing processes, into a dye solution in which dye and water
have been mixed in a constant ratio, the dye penetrates into fine
pores, by which the surface of the aluminum sheet is substantially
dyed.
[0024] Herein, when the aluminum sheet is dipped into the dye
solution, it is preferred that dye particles within the water be
most actively penetrated into the fine pores on the surface of the
aluminum sheet by properly setting the temperature of the dye
solution. It is also preferred that such a temperature be set
within a range of 40.degree..degree. C. to 50.degree..degree.
C.
[0025] From the foregoing, if the dye is penetrated into the fine
pores, the surface of the aluminum sheet can have a predetermined
color. Therefore, through a series of treatment processes mentioned
above, the surface of the aluminum sheet can have a desired color.
Consequently, the front sheet of the microwave oven having a
predetermined texture and a desired color can be produced.
[0026] And, another washing process (step 124) is again performed
after completion of the aforementioned dyeing process. This washing
process is a process for cleaning unnecessary dye remained on the
surface of the aluminum sheet.
[0027] If the coloration of the aluminum surface is completed after
going though the foregoing processes, a sealing process should be
performed in a step 126. The sealing process is a process for
stopping up the fine pores formed in the step 118 under the state
that a predetermined quantity of the dye is put into the fine pores
during the step 122. That is, by stopping up the fine pores, into
which the dye has been penetrated, so that discoloration and
removal of the dye can be prevented, the front sheet can be
constructed such that its change of color can be prevented although
it has been used for a long time. The above sealing process is
performed by dipping the dyed aluminum sheet into a solution, in
which boric acid and nickel acetate are mixed with each other in a
constant ratio (i.e., 5 g/l, respectively), during a predetermined
period of time. It is most preferable that the dipping process be
performed at a temperature above 75.degree..degree. C. and during a
period of time of about 15 minutes.
[0028] The front sheet according to the present invention is
completely formed by putting a predetermined color into the
aluminum sheet through the foregoing processes. If the surface
treatment of the aluminum sheet is completed, the front sheet made
of an aluminum sheet material according to the present invention is
attached to the front face of the microwave oven in a step 128.
[0029] The front sheet of the present invention, in general, has
the same configuration as being shown in FIG. 1. In order to attach
the front sheet to the door panel 1 of the microwave oven, etc., an
adhesive or a double-sided tape, for example, may be used.
[0030] The front sheet of the present invention may be attached to
the front face of the microwave oven via the other various methods
and constructions. Therefore, it is apparent that the present
invention should not be limited to the use of the aforementioned
adhesive, etc.
[0031] FIG. 3 shows an embodiment in which a front sheet 10 of the
present invention is attached to the door panel 1 of the microwave
oven. As shown, a mounting hole 1a is formed on a side of a lower
end portion of the front sheet 10, and a mounting projection 12 is
formed on a lower end of the door panel 1 at a position
corresponding to the mounting hole 1a. Therefore, coupling of the
front sheet 10 with the lower end of the door panel 1 is
substantially maintained, since the mounting projection 12 is
fitted into the mounting hole 1a when coupling the front sheet 10
with the door panel 1. Of course, such coupling structure may be
applied to upper end portions of the front sheet 10 and the door
panel 1. However, since the upper end portion of the door panel 1
can be easily seen by a user, it is preferable in view of its
appearance that the mounting hole and projection be not exposed
outward. Therefore, it is preferable to couple the upper end
portions of the front sheet 10 and the door panel 1 with each
other, using the adhesive, etc. as mentioned above.
[0032] In addition to the above coupling structure, it is needless
to say that the structure for coupling the front sheet with the
front face of the door, etc. may be changed or modified to the
other various forms.
[0033] Furthermore, as shown in FIGS. 1 and 3, it is understood
that the front sheet 7 of the present invention is installed to
wrap around at least a portion of the front, lateral, upper and
lower sides of the door panel 1. In addition, edge portions, where
the front side joins with the lateral side and the upper and lower
sides, respectively, are treated to have predetermined rounded
shapes. By the above treatment, whole appearance of the microwave
oven can be constructed to be much smoother.
[0034] According to the present invention constructed as such, it
is understood that the front sheet of the microwave oven is
manufactured to have a desired color by using the aluminum sheet
when manufacturing the front sheet. Therefore, the microwave oven
that can have both a metallic texture and a desired color can be
obtained by the application of the present invention.
[0035] Although the present invention has been illustrated and
described with reference to the exemplified embodiments of the
present invention, various changes, modifications and additions to
the present invention will be apparent to those skilled in the art
without departing from the spirit and scope of the present
invention, and the present invention should be construed only from
the appended claims.
* * * * *