Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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ELECTROSTATIC PROCESSING CHAMBER FOR PERFORMING
ELECTROSTATIC FLOCKING AND COATING OPERATIONS
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electrostatic processing
chamber for performing an electrostatic flocking operation and an
electrostatic coating operation, wherein a strip-like elongated
workpiece assuming a flat plate shape is subj ected to an electrostatic
flocking operation and an electrostatic coating operation in the
electrostatic processing chamber.
2. Description of the Related Art
When an electrostatic processing operation such as an
electrostatic flocking operation, electrostatic coating operation
and the like is performed in a condition in which: a strip-like
elongated flat plate having wound into a roll is unwound to
longitudinally extend; and, the thus unwound and extended flat plate
(including sheets of paper, textile fabrics, not limited only to
metal sheets) is electrically grounded to serves as a workpiece
to be flocked and coated when passedthroughanelectrostaticflocking
chamber and an electrostatic coating chamber in a condition in which
the flat plate is spaced apart form a electrostatically charged
element, a problem arises in the electrostatic flocking and the
electrostatic coating operation, which result in a poorly flocked
product and a poorly coated product, respectively. More specifically,
in each of the poorly flocked product and the poorly coated product,
the opposite longitudinal side areas adj acent to each of longitudinal
corner edge portions of these products are small in flock density
and in paint density. In contrast with this, each of the longitudinal
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corner edge portions itself are large in flock density and in paint
density.
This will be clearly described with reference to an example
shown in Fig. 1 in cross section. Namely, in the flocking operation
of the short fibers 4 with respect to the surface of the strip-like
elongated flat plate 2 (on which surface the adhesive layer 3 has
been formed) , the poorly flocked portion and the excessively flocked
portions both described above appear in the opposite longitudinal
side areas adjacent to each of the longitudinal corner edge portions
of the flocked product and in each of the longitudinal corner edge
portions itself, respectively.
Consequently, it is necessary to prevent the above phenomenon
from occurring in the electrostatic flocking operation of the
workpiece . This is because the f locked product having been subj ected
to such phenomenon fails to become a sound product. In other words,
in order to obtain the sound productwhich is uniform in flock density,
it is necessary to remove the opposite longitudinal side portions
of the f locked product having been subj ected to the above phenomenon .
Applicant is a company, which was established on September
16, 1979. Since this company's establishment, development in
technology relating to the electrostatic flocking process and the
electrostatic coating process is proceeding so that a considerable
amount of technological experience has been obtained by the company
(i.e., Applicant) . However, the company or Applicant does not know
in the art any electrostatic flocking chamber having a construction
or means for effectively preventing the above phenomenon from
occurring.
In filing the subject Patent application of the present
invention relating to the electrostatic processing operation such
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as the electrostatic flocking operation, the electrostatic coating
operation and the like in which the workpiece (i.e., strip-like
elongated flat plate having been unwound from its roll to extend
in its longitudinal direction) to be flocked and coated is passed
through the electrostatic flocking chamber and the electrostatic
coating chamber in a condition in which the longitudinally extended
flat plate is electrically grounded and spaced apart from the
electrostatically charged element, various kinds of developments
relating to the present invention have been required to be
accomplished. As a result, it is necessary to solve the
above-mentioned problem, which arises when the workpiece is
subjected to the electrostatic processing operation. The reason
why the above problem arises is that: when the strip-like elongated
flat plate (workpiece) is subjected to the electrostatic flocking
operation in a condition in which the flat plate is electrically
grounded and passed through the electrostatic flocking chamber,
the electric lines of force appearing in the electrostatic field
produced between the electrode (charged with the high voltage
electrostatic energy) and the workpiece having been electrically
grounded are not uniformly distributed in line density (which is
the number of the electric lines of force per unit area) on the
surface of the workpiece being flocked. In other words, since the
electric lines of force are concentrated in the longitudinal corner
edge portions of the flat plate, the floating short fabrics are
concentrated in these longitudinal corner edge portions . In contrast
with this, the opposite longitudinal side portions adjacent to such
longitudinal corner edge portions in the flat plate are small in
line density, and therefore poor in flock density (which is the
number of the short fibers per unit area) . This phenomenon has been
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found in the above-mentioned developments. Substantially the same
phenomenon as that found in the above has been found also in the
electrostatic coating operation.
The basic principles are identical for both the electrostatic
flocking process and the electrostatic coating process, which will
be now described hereinbelow.
In each of the electrostatic flocking technology and the
electrostatic coating technology, there is provided the electrode
to which a high voltage electrostatic energy is applied, wherein
the workpiece to be electrostatically processed is electrically
grounded and oppositely disposed from the electrode in the interior
of the electrostatic processing chamber. In operation, the high
voltage electrostatic energy is applied to the electrode to cause
an electric discharge oriented toward the workpiece, so that: by
using the electric lines of force issued from the electrode to the
workpiedcein the electrostaticfieldcreated between the electrode
and the workpiece, fine objects floating between the electrode and
the workpiece in the interior of the electrostatic processing chamber
are electrically charged; and, the thus charged fine objects are
driven to fly toward the workpiece. This is the basic principles
oftheelectrostatic processing operationssuch astheelectrostatic
flocking operation and the electrostatic coating operation.
A remarkable difference between the electrostatic flocking
technology andthe electrostaticcoatingtechnology residesinthat:
in the technology relating to the electrostatic flocking operation,
the fine objects floating in the electrostatic processing chamber
are short fibers which are electrically conductive; the workpiece
to beelectrostatically processedisan electrically grounded object
coated with an adhesive layer formed of an adhesive which is still
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not dried; and, the electrostatic f locking operation of the workpiece
is performed in a manner such that : the short f fibers are electrically
charged when the electrostatic field is created between the electrode
and the workpiece; and, by using the electric lines of force formed
5 in the electrostatic field, the short fibers are driven to fly toward
the adhesive layer of the workpiece, and thereby having their front
end portions stuck into the adhesive layer of the workpiece, whereby
the electrostatic flocking operation is completed, wherein: an air
flow may be produced in a manner such that the air flows from the
electrode to the workpiece; or, any air flow does not exist between
the electrode and the workpiece.
In contrast with this, in the technology relating to the
electrostatic coating process: the above-mentioned fine objects
floating in the interior of the electrostatic processing chamber
are constructed of a fine coating powder or liquid provided with
insulation properties; the workpiece to be electrostatically
processed is an electrically grounded obj ect still not coated with
any adhesive layer; and, by using the electric lines of force in
the electrostatic field created between the electrode and the
workpiece, the electrostatic coating operation is performed in a
manner such that: the coating powder or liquid is electrically
charged; an air flow is formed between the electrode and the workpiece
so as to have the air flow from the electrode toward the workpiece;
and, due to a synergistic effect between the electrostatic field
and the air flow, the coating powder or liquid is driven to fly
toward the surface of the workpiece, so that the coating powder
or liquid is attracted to the surface of the workpiece under the
effect of the electrostatic charge of the coating powder or liquid.
The basic principles are identical for both the electrostatic
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flocking process and the electrostatic coating process since both
the electrostatic processes use the electric lines of force in the
electrostaticfieldcreated between the workpieceandtheelectrode.
However, these electrostatic processes are different from each other
as to only two points, that is, : the workpiece to be electrostatically
processed; and, the fine objects electrically charged to float.
As for the arrangements or positional relationship between the
electrode and the workpiece in the housing, there is substantially
no difference in construction between these electrostatic
processes.
In other words, in construction of the housing: the electrode
is disposed; and, oppositely disposed from this electrode is the
workpiece having been electrically grounded. Due to the above
construction, the electrostatic field is created between the
workpiece and the electrode, so that the electric lines of force
extend from the electrode to the workpiece.
SUMMARY OF THE INVENTION
It is an obj ect of the present invention to realize a uniformly
flocked or a uniformly coated surface of a workpiece by preventing
fine objects from being: poorly flocked in or applied to opposite
longitudinal side areas of the workpiece, which side areas adjacent
to each of longitudinal .corner edge portions of the product; and,
excessively flocked in or applied to each of the longitudinal corner
edge portions itself when an electrostatic flocking operation or
an electrostatic coating operation is performed in a condition in
which: a strip-like elongated flat plate having wound into a roll
is unwound to longitudinally extend to form a flat plate which forms
the workpiece; and, the workpiece is electrically grounded so as
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to be flocked and coated when passed through anelectrostatic flocking
chamber.
Consequently, regardless of the movements of the flat plate,
the electrostatic processing operation is not performedwith respect
to the flat plate when the flat plate is held by a holding member
having been electrically grounded.
In accordance with a first aspect of the present invention,
the above object of the present invention is accomplished by
providing:
In an electrostatic processing chamber for forming an
electrostatic flocking apparatus to perform an electrostatic
flocking operation, wherein a strip-like elongated flat plate
serving as a workpiece coated with an adhesive layer and electrically
grounded is oppositely disposed from an electrode and transferred
in a condition in which short f fibers having been electrically charged
are electrostatically implanted in the flat plate, the improvement
wherein: electrically grounded elongated elements are disposed in
opposite longitudinal side areas of the flat plate to extend in
parallel with a longitudinal direction of the flat plate in a passage
of the strip-line elongated flat plate being flocked.
In accordance with a second aspect of the present invention,
the above object of the present invention is accomplished by
providing:
An electrostatic processing chamber for forming an
electrostaticcoating apparatusto perform an electrostaticcoating
operation, wherein a strip-like elongated flat plate serving as
a workpiece electrically grounded is oppositely disposed from an
electrode and transferred in a condition in which the workpiece
is subjected to an electrostatic coating operation, the improvement
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wherein: electrically grounded elongated elements are disposed in
opposite longitudinal side areas of the workpiece to extend in
parallel with a longitudinal direction of the flat workpiece in
a passage of the strip-like elongated flat plate being coated.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, advantages and features of the
present invention will be more apparent from the following
description taken in conjunction with the accompanying drawings
in which:
Fig. 1 is a view illustrating the prior art applied to the
workpiece; and
Fig. 2 is a view illustrating the present invention applied
to the workpiece.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The best modes for carrying out the present invention will
be described in detail using embodiments of the present invention
with reference to the accompanying drawings.
The present invention may, however, be embodied in various
different forms and should not be construed as limited to the
embodimentssetforth herein;rather, these embodimentsare provided
so that this disclosure will be thorough and complete, and will
fully convey the scope of the present invention to those skilled
in the art.
The basic technical idea of the present invention has resulted
in the provision of a suitable means for preventing the electric
lines of force from concentrating in each of longitudinal corner
edge portions of the workpiece. The provision of such a suitable
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means is capable of solving the following problem, which will be
now described in detail: namely, when an electrostatic processing
operation such as an electrostatic flocking operation,
electrostatic coating operation and the like is performed in a
condition in which: a strip-like elongated flat plate having wound
into a roll is unwound to longitudinally extend; and, the thus unwound
and extended flat plate (hereinafter referred to as the workpiece
2) is electrically grounded so as to be flocked and coated when
passed through an electrostatic flocking chamber and an
electrostatic coating chamber, the problem arises in the
electrostatic flocking and the electrostatic coating operation,
which result in a poorly flocked product and a poorly coated product,
respectively, wherein: the opposite longitudinal side areas
adjacent to each of longitudinal corner edge portions of these
products are small in flock density and in paint density; and, each
of the longitudinal corner edge portions itself are large in flock
density and in paint density.
According to the present invention, as shown in Fig. 2, in
construction of each of the electrostatic flocking chamber and the
electrostatic coating chamber (both of which chambers are
hereinafter referred to as the housing) : an electrode 1 is disposed
inside the housing (not shown); oppositely disposed from the
electrode 1 is the workpiece 2 which is constructed of the strip-like
elongated flat plate and transferred in the interior of the housing;
and, a plurality of electrically grounded elongated elements 5 are
disposed in opposite longitudinal side areas of the workpiece 2
to extend in parallel with a longitudinal direction of said the
workpiece 2 in a passage of the workpiece 2 being electrostatically
processed, wherein each of the grounded elements 5 is slightly spaced
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apart from the workpiece 2.
It is possible to mount each of the electrically grounded
elongated elements 5 in the housing by using the same mounting means
as that used in mounting an electrically grounded shelf (which
5 supports the workpiece thereon) in the housing. Consequently, no
special provision of means for supporting the elongated elements
5 is required in the present invention.
Hereinbelow, the electrostatic flocking operation of the
workpiece 2 will be described, as an example.
10 The electrostatic flocking operation is performed in a
condition in which: the electrically grounded elongated elements
5 are mounted along the passage of the workpiece 2 in the housing;
the workpiece 2 is transferred through the passage; and, flock or
short fibers 4 are electrostatically charged to float in the housing
as is in the conventional ordinary operation.
In other words, in the above operation, the workpiece 2 is
electrically grounded and transferred in the housing in a condition
in which the workpiece 3 has its adhesive-layer formation surface
3 oppositely disposed from the electrode 1, wherein: an adhesive
layer is formed on the adhesive-layer formation surface 3 of the
workpiece 2; and, a high voltage higher than that used in the
conventional ordinary process is applied to the electrode 1.
In the above operation, an electrostatic field is created
between the electrode 1, workpiece 2 and the elongated elements
5. The electric lines of force in this electrostatic field extend
to the adhesive-layer formation surface 3 of the workpiece 2.
As a result, the short fibers 4 charged inside the housing
are electrostatically driven to fly toward the adhesive-layer
formation surface 3 of the workpiece 2 and also toward the elongated
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elements 5, so that the short fibers 4 reached the adhesive-layer
formation surface 3 of the workpiece 2 have their front end portions
stuck in the adhesive-layer formation surface 3, whereby the
workpiece 2 is electrostatically flocked. On the other hand, the
short fibers 4 flying toward the elongated elements 5 fail to have
their front end portions stuck in the elongated elements 5 since
the elongated elements 5 are not coated with any adhesive layers.
As shown in Fig. 2, in the present invention: since the
electrically grounded elongated elements 5 are disposed adjacent
to and parallel to the opposite longitudinal side areas of the
workpiece 2, the electric lines of force appearing in the
electrostatic field created between the electrode 1 and the
adhesive-layer formation surface 3 of the grounded workpiece 2
substantially uniformly extend also to the opposite longitudinal
side areas adjacent to each of the longitudinal corner edge portions
of the workpiece 2, without concentrating only in the longitudinal
corner edge portions of the workpiece 2.
In other words, the electrically grounded elongated elements
5, which is disposed adjacent to and parallel to the opposite
longitudinal side areas of the workpiece 2, function to prevent
the electric lines of force from concentrating in the longitudinal
corner edge portions of the workpiece 2.
Due to the above effect of the elongated elements 5, it is
also possible to prevent the short fibers 4 (which are electrically
charged to float) to concentrate in the longitudinal corner edge
portions of the workpiece 2.
As a result, it is possible to prevent the longitudinal corner
edge portions of the workpiece 2 from being excessively flocked,
and therefore also possible to prevent the opposite longitudinal
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side areas adjacent to each of the longitudinal corner edge portions
of the workpiece 2 from being poorly flocked.
Although the workpiece to be electrostatically flocked has
been described in the above with reference to the example,
substantially the same phenomenon that is observed in the above
maybe observed also in the electrostatic coating operation, provided
that the electrostatic coating operation is different from the
electrostatic flocking operation in that: the workpiece used in
the electrostatc coating operation is not covered with the adhesive
layer; and, the fine objects to be applied to the workpiece are
coating materials in the electrostatic coating operation.
Further, the present invention is applicable not only to the
up-type electrostatic flocking chamber, but also to a down-type
electrostaticflocking chamber, a side-type electrostaticflocking
chamber, and the like.
The effect of the present invention is as follows: namely
As described above, according to the present invention, it
is possible to uniformly flock the workpiece through the
electrostatic flocking operation by the provision of the
electrically grounded elongated elements disposed adjacent to the
opposite longitudinal side areas of the workpiece, wherein the
workpiece is oppositely disposed from the electrode.
Finally, the present application claims the Convention
Priority based on Japanese Patent Application No. Hei 11-228367
filed on August 12, 1999, which is herein incorporated by reference.
