Note: Descriptions are shown in the official language in which they were submitted.
--`` 132~78~
S E~E~ C I F ~C C A T I O N S
Title of the Invention
Metal Container and Method of Manufacturing the same
The Background of the Invention
; This invention relates to a metal container for the
pressurized material and to a method of manufacturlng the
same.
Metal containers, in other words, pressure holding
containers have been largely used for aerosol containers
and others, and there is still a large demand therefore in
the various indiustrial fields.
~, A container of this type, in t:he prior art, was mainly
formed by the step of drawing raw material into a
cylinderical body with an integral bottom and processing
-, also the top part to be smaller in diameter for the mouth by
so-called necking procedures, whereon the top is closed by
another member equipped with valve apparatus in the final
stage of the completion.
The metal container complet~d through the above
procedures in the prior art, however, i5 restricted in
selecting the raw material, like aluminum, since it needs
ductility and to be easily cast. Further, the completed
container is not strong enough for the pressure endurance
because of the nature of material itself.
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In order to obtain the better endurance of ~he pressure,
U.S.PATENT No.4,241,~44 disclosed the following
manufacturing method. First, draw the cylinderical body
having at its one end the smaller diameter and having its
othèr end opened, i.e.with no integral bottom at all, and
with the same diameter as the cylinderical body, and then
~ fit a disc-like bottom plate produced by another step ln the
; open end by the adhesive joint means and caulking means.
This method accordingly allows the use of harder m~tallic
material than aluminum, such as steel plate, and thus the
cylinderical body is able to be made of steel plate as the
sai~ body is produced by means of the step with open end.
After the bottom plate is inserted and furnished with
adhesive in the bottom portion of the cylinder, the end part
l of the said bottom portion interfolds the s~id bottom plate,
~;1 and the caulking is made, whereon the satisfactory pressure
endurance is sustained.
With the above mentioned method, however, there i5 a
problem in obtaining a good sealing in a satisfactory
l~ condition. Inserted forcibly in the bottom portion of the
3 cylinderical bod~ furnished with adhesivet the bottom plate
i~ causes the friction enga~ement in its skirt portion of the
~3~ ourter cir~umference with the inner wall of the cylinder,
;~ and this engagement sweeps the adhesive upwardly and finally
the ~dhesive retains like a semilunar-like group just over
` the place between the inner wall and the shoulder of the
bottom plate. After the insertion is finished, the
similunar-like group of the adhesive exists all around in
the inside. As above explainedr because of the friction
effect, the adhesive does not almost exist correctly between
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the whole outer circumference of the bottom plate and the
inner wall of the cylinder, and thus the sealing is only
kept by the said semilunar-like collective group of the
adhesive. Thus, the effective surface of the adhesive which
is to cover the whole outer circumference of the bottom
plate with the inner wall becomes quite small, whereas the
desirable and satisfactory sealing is not obtained.
The relative discloure indicates the use of strong
adhesive of hardening type, and therefore when the adhesive
comes to a collective group as mentioned aforsaid, the
flexibility of the adhesive cannot be attained, and the said
group is easily detached or broken against the pressure
change caused by the inner forces or against the
.,.!transformation of the bottom plate or that of the cylinder
lower portion caused by the impact load, whereon the sealin~
is sometimes broken.
Therefore, it is the main object of this invention to
resolve the problems as mentioned above.
The present invention has an object to provide a metal
container ~nd a method of manufacturing the s~me with a
satisfactory seal between the cylinder and the bottom plate.
~1It has a further object to provide a method of
manufacturing a metal container which maintains the good
seal by increasing the adhesive effective areas between the
inner wall of the cylinder and the outer circumference of
the bottom plate.
It is another object to provide a method of manufacturing
a metal container with the improved seal by preventing the
adhesive from becomin~ a semilunar-like collective group
even if a hardening type of adhesive is used.
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It is a still further object to provide a method of
manufacturing a metal container with an improved seal by
retaining the adhesive in the required place in thP case of
high-viscose adhesive usage~
It is yet another object to provide a method of
; manufacturing a metal container with a resistant seal on a
joint point against a pressure change or against an impact
load.
It is yet a still further object to provide a method of
i manufacturing a metal container which can be produced on
present exisiting e~uipment without any excessive capital
investment.
It is a further object to provide a method of
manufacturing a metal container with an improved seal by
j adopting a method to form a piece or plural pieces of ditch
on the skirt portion of the bottom plate, along the said
ditch the adhesive runs upto the curling portion, whereafter
!1' the adhesive is hardened to overlap on the whole gaps
;~ therewith.
Other objects and advantages of the present invention
will be apparent upon reference to the accompanying
descriptions.
Summary of the Invention
,
This invention relates to a metal container and a method
of manufacturing the same, wherein the separate bottom plate
is fitted in the cylinderical body by adhesive joint means,
and it is characterized in increasing the effective areas
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for adhesive between the inner wall of the cylinderical body
and the outer wall of the bottom plate, improving the seal
of the adhesive joint means by preventing the hardening
; adhesive from coming into a semilunar-like collective group,
and precludin~ damages on the sealing part and deterioration
of the sealing power caused by the pressure change or the
impact load.
-~ If a high-viscose adhesive is utilized, it is adapted to
make the relative adhesive coming in-to the whole gaps
correctly 50 as to increase the sealing ability, whereas
both damages and deterioration of the sealing joint part are
prevented against the pressure change and the impact laod~
Furthermore, it is characteriæed in forming a piece or
plural pieces of ditch on ~he skirt portion of the bottom
plate, along the said ditch the adhesive runs through upto
the curling portions whereafter the adhesive is hardened to
overlap on the whole g~ps properly, which promotes the
increase of the effective areas for the adhesive and also
;the sealing ~bility and also promotes the shock resistant
powers caused by falling.
Brief descriptions of the drawings.
;FI~.1 and FIG.2 show a prior art metal container, FIG.1
being a cross-sectional view showing the container just
before a bottom plate is fitted to a cylinderical body,
while FIG.2 is a fragmentary cross-sectional view showing
the arran~ement when the said plate is fitted to the body.
FIG.3 is a fragmentary cross-sectional view of a metal
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`` 132978~
container showing the position just before a bottom plate is
fitted to a lower portion of the cylinderical body.
FIG.4 is a fragmentary cross-sectional view showiny the
arrangement when the bottom plate is adhesively secured in
the body.
FIG.5 and FIG.6 are cross-sectional views showing
perspective curling steps.
FIG.7 is a perspective view showing the supply of
adhesive.
FIG.8 is a cross-sectional view showing an alternative
style of bottom plate.
FIG.9 is a plan view showing the step to provide a
specimen for a stripping test.
FIG.10 is a perspective view of the said specimen.
~t FIG.11 and FIG.12 are schematic views for the relative
testing method.
! FIG.13 and FIG.14 are a further embodiment, with FIG.13
being a cross-sectional view showing the working arrangement
while FIG.14 is a fragmentary sectional view showing the
adhesive joint part between the cylinderical body and ~he
bottom plate.
FIG.15 to 17 show a still further embodimentl- with FIG.15
being a fragment~ry sectional view showing the working
arrangement, while FIG.16 is a fragmentary sectional view
showing the step of curling and FIG.17 is a fragmentary
sectional view showing the arrangement when the bottom part
is jointed with the cylinderical body.
FIG.18 and FIG.19 show a yet further embodiment, with
FIG~18 being a perspective view of the bottom plater while
FIG.19 is a fra~mentary sectional view showing the joint
'
132978~
between the cylinderical body and the bottom plate.
,
Detailed descriptions of Preferred Embodiments
.
The preferred embodiments are now explained in accordance
with the drawings.
FIG.l and FIG.2 show the construction and manufacture of
a prior art metal container. The present invention is
substantially based on the said construction/ but it
~1 increases the adhesive effect between a cylinder11) and a
l bottom plate(2) as well as improving the sealing ability
thereof.
Referring to FIG.1 and FIG.Z, the cylinder(1) has its
lowex end open and its other end drawn into a smaller
. .
diameter top, where a dispensing means(24) such as a cap
with an emitting valve is provided, the body between the
ends being cylinderical. The bot:tom plate(Z) i5 inserted
into the said open end of the cylinder(1) to form the lower
closure of the cylinder(1), and it is in the form of a disc
with a dome-like top portion(Z2) and a depending skirt
portion(21~.
Adhesive(3) is applied between the fringe of the bottom
plate and the inner wall of the cylinder~1) and the sealing
joint part is formed between the two components. The lowest
part of the cylinder(l) is subject to a curling operation
and this folds over the skirt portion(21) of the bottom
plate~2), whereon the skirt portion is pinched by the
lowermost of the cylinder to produce resistance against
movement of bottom plate(2) out of the cylinder(1) as a
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result of inner pressure.
In the prior art metal container, the adhesive applied
between the cylinder(l) and the bottom plate~2~ tends to
come a semilunar-like collective group between the shoulder
of the bottom plate~2) and the inner wall of the cylinder(l)
as a result of the frictional engagement of the bottom
plate~2) with the inner cylinderical wall during the
insertion procedure.
As above r when the adhesive comes together in a
semilunar-]ike group, the flexibility or the elasticity of
the adhesive is lost, and as a result of the internal
pressure or the impact load breaks the adhesive effect and
,;
the sealing ability is lost, because both the cylinder and
the bottom plate cannot withstand such internal pressure nor
the impact load.
This invention aims to resolve these problems as
mentioned above.
With reference to FIG.3 to FIG.13, the cylinder(l) and the
bottom plate(Z) are the same as those of the prior art, and
in the a & esive application step the adhesive is supplied
~ircumfrentially along the inner wall of the open end~11) of
the cylinder~1). In this step, as shown in FIG.7, a
nozzle(N) of an adhesive container is placed to a defined
portion of the inner wall of the cylinder(l) and runs at 150
rpm.,for example, and the adhesive agent is, for example~
dispersed at 18 c.c. per minute, the adhesive(3) being
applied circumferentially along the inner wall of the open
end(11) as shown in FIG.3. The adhesive applied area must
be the contacting area between the skirt portion(21) and the
inner wall of the cylinder(l) when the bottom plate is
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fitted in the cylinder~1).
The bottom plate~2) is inserted into the cylinder body
furnished with adhesive from the open end ~11 ) r and as shown
in FIG.4, the bottom end of the skirt portion(21) and the
open end ~ of the cylinder~1) become axially aligned,
i.e.,flush. In this situationr the adhesive~3) as shown in
FIG.4 comes a semilunar-like group around the periphery of
the dome-like portion~Z2) of the bottom plate~2).
The assembled body of the said cylinder(1~ and the said
bottom plate(2) is then placed upside down, and subject to a
curling procedure as shown in FIG~5 and FIG.6. The curling
method is similar to the prior art method, and during the
curling step, the bottom plate~Z~ is forcibly pushed
inwardly into the cylinder(1) as the open end portion(11) is
bent to interfold the bottom plate(2). After the said
curling is finished the curling portion is formed
circumferentially all around the bottom end of the skirt
portion~21) as shown in FIG.6r and finally the said skirt
portion~21) is pinched by the curling portions. After this
curling procedure, until the adhesive~3) runs dry to be
hardened, the condition of standing upside down must be
maintained, during which the adhesive~3) runs along the
surface of the cylinder inner wall and along the dome-like
portion~2) by the liquidation of the adhesivel3). In order
to obtain this natural flow of the adhesive~3~, it may be
necessary only to keep this container standing upside down
for stocking. By this procedure, the flow of the
adhesive~3) is along the inner wall of the cylinder~1), and
it is also along the slope toward the domed middle of the
bottom plate, whereas the semilunar-like collective group of
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the adhesive(3~ which is the fatal defect of the prior art
is completely cleared, and in this case, the semilunar-like
group comes in convex style in stead of the previous concave
style.
In the said embodiment, the following material are
available for forming the cylinder(1) : Steel plate, Steel
plate furnished with aluminum plating, aluminum sheet,
cladding steel plate and compound steel plate furnished with
plastics coating in its inside.
The following adhesive agents are available for the said
embodiment : Epoxy solvent agent such as epoxy-amine type,
or epoxy-urethane adhesive with high~viscose quality.
In this embodiment, the upper end of the skirt
portion(Z1) can be provided with some taper, but this end
can alternatively without any tc~per, as shown in FIG.~,
having the hemispherical part(23), which is also easy and
smooth to allow the said bottom plate(2) to be fitted into
the cylinder~1).
The gap tolerance between the bottom end~11) of the
cylinder and the skirt portion(21) is preferably between O.1
to 0.3 mm. In the case where the skirt portion is equipped
with taper, as shown in FIG.4, some small circumferential
gaps are formed, into which the adhesive(3) flows. In other
words, at least~ on the upper part of the skirt portion,
adhesi~e is accordingly provided.
The application of the adhesive~3) and the fittiny of the
bottom plate~2) are made in compliance with the prior art.
With the invention, the cylinder(1) is kept as standing
upside down, and the caulking is performed on the skirt
portion(21). During the time when the caulking is performed
,
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and/or the maintenance time of keeping the above standing,
the adhesive(3) runs down along the inner wall of the
cylinder(1) from its semilunar-like group, and accordingly
the said group of the adhesive(3) is gradually running lower
and finally it changes its form into the convex style from
its original concave style. Keeping this arrangement r the
adhesive joint part is dryed and the resultant cylinder(1)
is surely jointed around the hemisphere of the bottom
plate(Z).
The adhesive is now applied over the circumferential edge
part of the dome portion(22) and over the inner wall of the
cylinder(1) in even thickness, as seen in the convex style
between the bottom plate~Z) and the cylinder(1). Therefore,
the adhesive applied areas can transform themselves in
correspondence with the transEormation of the dome
portion(ZZ) and the inner wall of the cylinder~1).
Even if the applied adhesive is fixed in qu~ntity, the
effective surface for the adhesive is larger in comparison
with the prior method in which the semilunar-like collective
group is unavoidable.
As above explained, the adhesive applied are~s can
tranform themselves accordingly by which the damage by
pressure change or impact load is avoided and the
satisfactory sealing is kept correct. At the same time, the
increase of the effective areas for the adhesive also
promotes the sealing ability when compared with the same
produced by the prior art.
With regard to the present invention, a stripping test
was performed and the relative data are now indicated and
explained follows :
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The test container was of the following construction :
Diameter : 50mm
Height : 1Z4mm
i Thickness of the cylinderical body at the joint part:
O.Z7mm
.-l Thickness of the bottom part at the joint part: 0.36mm
~.' Ma~erial : aluminum alloy
; Adhesive : Epoxy polyamide plastics adhesive 0.6 gram
.~ used.
The test specimen was adopted, as shown in FIG.9, cuttin~
the piece down at 5mm wide at 120 degree interval, and the
specimen was completed in the manner of FIG.10.
The testing was performed, as shown in FIG.11 and FIG.1Z,
with the application of a pull gauge. Bottom side~25a) w~s
stablized firmly and cylinder sid.e~25b) was connected with
the pull gauge, whereon the operation of pulling was
employed with readings of the pull gauge being taken.
The test result for 10 pieces is shown in the following
"
table :
~:'
~: N mber_of_sReci_enla lb _ _lc Za _2b _ Zc_
;; Stripping Power~K~12.9 1_3.5_13.4_ 13.4__l3.0 l3.5__
Specimen 3a 3b 3c4a_ 4b 4c 5a 5b _5c
.~ Power _ 13.2 13.3 13.6 13.4 13.4 13.3 13.4 13.7 13.2
.,
,
-- Specimen 6a 6b 6c 7a 7b 7c ~a 8b 3c
. .
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~ Power lZ.7 13.6 13.4 13.1 13.4 12.7 13.5 13.3 14.0
, ~
Specimen 9a 9b_ 9c 10a __lOb _ lOc
_ower 13.5 13.3 13.4____13.0 _13.5_ 13.6_
J
, .,
At the same time, the same testing was performed for the
container which was manufactured by the prior art in the
semilunar collective group of adhesive, and the relative
result is as below :
:'
:~:
Specimen Number 11a11b _ llc_ 12a _ 12b _12c
~ S ripping Power 3.5 .3.1 3.9 - .4.--?~ 4-4 3-8
~'
Specimen 13a 13b_ 13c 14a _14b 14c 15a _l_b _15c
Power 4.1 2.9 4.1 4.5 3.4 3.6 3.3 4.5 4.1
: . _ .. ____
Specimen 16a_ 16b _l6c 17a 17b 17c l~a 18b 18c
Pow~r _____3 4 3 5 3.Z 3.0 3.5__3 4 3.7 2.8 3.3
~;"
Specimen l9a_ 19b_ 19c 20a _20b ?oc
. Power 3.6 3.4 4.0 4.3 3.6 3.8
~, . . . . . . . . _ _ _ . _ _ _ _ . . .. _ _ . .
. ..
. ~
On checking the above data, the stripping power against
the present invention shows 14.0 kgs at maximum and 12.7 kgs
.,.~.
at minimum, and 13.34 kgs at average, while the same power
against the pr.ior art shows 4.5 kgs at maxim~n and 2.8 kgs
at minimum, and 3.66 kgs at average, all of which show that
. !
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132978~
the strength of a container joint of this invention is
~pproximately 3.5 times that of the prior art.
The recommendable adhesive is epoxy typer non-solvent,
two-part adhesive, and hardening type such as epoxy-amine
aidhesive, epoxy-polyurethane adhesive and epox~-polyamide
~idhesive.
The adhesive used in the ~bove ~ield test is epoxy-
poliamide type in the following consitutions ~
MAIN AGENT HARDENIN_ AGENT
EPOXY ~UANTITY 165~185
~MINE VALUE - 400~440
VISCOSITY 5000~7000 CPS 4000~5000 CPS
P RCENTAGE_ __ _ _ 75 Qo _ 2 ~
, .
Now, with reference to FIG.13 and FIG.14, a modified
embodiment is explained. In this modification, all elements
between cylinder(1) ~nd the bottom plate(2) including their
constitutions of the joint working and adhesive furnishing
aire substantially same as explaiined in FIG.3 to FIG.8. The
embodiment has its characteristic in providing extra
pressure into the inner side of the container from the
outside~
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132~7~5
By the extra power of pressure, the semilunar-like
collective group of adhesive is now prevailing over the
inner wall of the cylinder(1) and also over the dome
portion~2~ of the bottom plate(2), and finally the
semilunar-like group comes in the shape of convex by
distribution of its adhesive.
After assembling the bottom plate(2) into the
cylinder(1~, a pressure difference is established between
the inside and the outside, in other words, high pressure is
put into the inside. The applied adhesive is urethane type
belonging to the epoxy-amine system. If the pressure
increasing step is effected independently, the pressure
condition applied cab be a few atomospheric pressures for a
few seconds. The above condition depends upon the size of
the gap between the cylinder(1) and the skirt portion(21) of
the bottom pla~e(2) and also upon the viscosity of the
applied adhesive. In a case where the gap is l~rger and
viscosity is weaker, the pressuring time must be shortened
,;
accordingly, while if the gap is smaller and the viscosity
is stronger the time must be increased.
As above mentioned, when the pressure is received in the
interior, the semilunar-like collective group of the
adhesive is forced to flow forcibly into the gap between the
open end(11) and the skirt portion~21~, and the gap is
~ .,:
filled with the adhesive as the result. When the pressure
is removed, the adhesive stays as it is in the gap.
The pressuring step is an independent step as above
; mentioned, but this relative step proceeds simaltaneously in
correspondence wi-th the curling step.
The flow of the adhesive is now explained with the
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curling step as follows :
As shown in FI~.13 and FI~.14, during the curling step,
the open end (11 ) of the cylinder(1) is bent to the inside
for curlinq. The method of this curling is exactly the same
as in the prior art, and during the curling step the
adhesive has still not yet hardened as the bottom plate(2)
is pushed into the inside of the cylinder(1). When the
curling step is completed, the curling portions are formed
around the bottom end of the skirt portion(21) as shown in
FI~.14, and thus the said skirt portion(21) is pinched by
the curling portions.
During the above steps, as shown in FIG.13, the inside of
the cylinder(1) is receiving the fixed pressure, and the
adhesive(3) is thus forced to flow into the gap between the
cylinder~1) and the skirt portion(21). Under these
conditions, the bottom plate(2) is pushed into the inside by
the curling step. In compliance with the two factors that
the bottom plate(2) is forcibly moved into the inside and
that the continuous pressure is malintained, the adhesive(3~
is compelled to flow into the said gap even if the pressure
time is quite short.
J As shown also in FIG.13, there is a pressure supply line
from a pressure supply~P.S.~, and it is properly controlled
in correspondence with the curling step. By this
arrangement the fixed pressure in the inside of the cylinder
is correctly kept and simultaneously the curling step is
progressed, and thus the adhesive(3) forcibly flows into the
gap between the cylinder(1) and the bottom plate(2).
In this embodiment, at the same time as the bottom
plate(2) is pushed into the cylinder(1), the adhesive(3) is
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also pushed into the gap between the cylinder(1) and the
skirt portion~21), whereas the semilunar-like collective
group of the adh~sive on the upper part of the skirt
portion(21) is gradually broken down to move into the gap.
In this embodiment, the following material is available
for the cylinder : Steel plate, steel plate furnished with
aluminum plating, aluminum sheet, thin cladding steel plate
and compound steel plate furnished with plastics coating in
its inside.
the applicable adhesive : Epoxy type, two-part adhesive
such as epoxy-amine agent, epoxy-urethane agent and so on,
with quality of strong viscosity.
After the step of puttin~ adhesive on the inner wall of
the cylinder(1), the bottom plate(2) is inserted from the
open end(113 oE the cylinder(1), and at this instant the
adhesive(3) forms the semilunar-like group at the upper part
of the skirt portion(Z1). Then the fixed pressure i5 pUt
into the inside of the cylinder(1), and the semilunar-like
group of the adhesive(3) is forced to flow into the said
joint section. In other words, the gap is filled with the
adhesive. According to the ~low of the adhesive~3) as
.~
above, the semilunar-like group is gradually broken down
into a formation of convex type, contrary to the semilunar-
like form. Namely, the adhesive flows itself over along the
inner wall of the cylinder~1~ and also over along the
inclined surface of the skirt portion~22) into the average
thickness, whereas the adhensive supplied areas arP easy to
transform in accordance with the transformation of the wall
or that of the skirt portion(21). The adhesive(3) in those
areas stays as it is.
.,
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In succession to the aforsaid pressuring step, the open
end(11) is bent inwardly for curling the skirt portion(21)
and finally the said portion is caulked, whereas the bottom
plate(2~ is fixed in the lower portion of the cylinder(1).
Thereafter, the adhesive(3) is dryed and hardened to
connect tightly the joint section between the cylinder(1)
and the bottom plate~2).
Thus, the adhesive(3) flows forcibly into the gap between
the cylinder(1) and the skirt portion(Z1), and the said gap
is filled with the adhesive(3). Accordingly, the adhesive
prevailed areas may transform by themselves in
correspondence with the transformation of the inner surface
of the skirt portion(21) and also with that of the cylinder
inner wall, whereas the sealing joint se~tion is neither
damaged by an intsrior pressure change insidedly or by an
impact load nor the sealing ability is deteriorated.
Moreover, the contacting surf~ce between the inner wall
of the cylinder(1) and the skirt portion(21) is larger in
comparison with that of the prior art, and therefore the
sealing ability is much greater.
During the simpl~ step of ~dding pressure to cause flow
of adhesive, the adhesive itself does not change in quality.
,
With refence to FIG.15 to 17, another modification of the
invention is explained. The previous modification depended
upon a pressure adding method, but the present modification
is concerned with the extra heating.
According to FIG.15, the assembled body of the
cylinder(1) and the bottom plate(2) is upright, whereon
heating is temporarily employed upon the adhesive joint
.
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section~ The applied adhesive is urethane type belonging to
epoxy-amine system, and the heating condition is defined at
150 degree C for a few seconds. Heated, the semilunar-like
group of the adhesive(3) at the upper part of thP skirt
portion(21) gradually runs down into the gap between the
open end(11) and the skirt portion(22) because the viscosity
is weakened by the heating procedure, and finally the gap is
filled with the adhesive(3). Immediately after the heating
procedure i5 stoppedy the adhesive regains its original
viscosit~v.
As a heating procedure, as shown in FIG.15, an infrared
he~ter H is recommended, or else a high-frequency heater is
also applicable.
As shown in FIG.16, the open end(11) is bent inwardly for
the curling step. The curling st~p is the same step as for
the prior art. In the curling step, the bottom plate(2) is
pushed inwardly into the inside o~ the cylinder(1), and at
the final stage of the relative curling step the curling
portion is formed to surround the bottom end of the skirt
portion(21), wherefore the skirt portion(21) is pinched by
the relative curling portions.
The applicable adhesive is recomm~nded : Two-part
adhesive of epoxy type such as epoxy-amine adhesive, epoxy-
urethane adhesive with the quality of the strong viscosity.
In this modified embodiment, the heating procedure is
expressed as an independent step, but this procedure may be
included together with the insertion step of the bottom
plate(2~. In a case where the above co-procedure is
adopted, the semilunar-like collecting group of the adhesive
comes very small.
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-- 132978a
After the adhesive(3) is furnished, where the bottom
plate(Z~ is inserted from the open end (11 ) of the
cylinder(1) the semilunar-like collective group of the
adhesive(3) is formed at the upper part of the skirt
portion(21). As the applied adhesive is of strong
viscosity, enough volllme of the adhesive does not exist in
the joint section between the cylinder(1) and the skirt
portion(21).
Once the heating is applied on the said joint section to
weaken its viscosity, the semilunar-like collective group of
the adhesive(3) flows into the gap of the said joint section
and the adhesive(3) fills the said gap. The semilunar-like
group of the adhesive(3) gradually decreases its group unity
to change into the convex style, and the average prevailing
areas of the adhesive(3) adjus~ themselves to transform in
correspondence with the transformation of the cylinder
inside wall and with that of the skirt portion(~1). The
adhesive(3) recovers its orlginal viscosity after the
heating is stopped, and thus the adhesive(3) remains filling
in the said joint section.
Then, the bottom plat~(2) is tightly fixed at the lower
part of the cylinder(l) through the steps of the said
..... :
~. curling and caulking.
: ,,
~: When the adhesive is dryed and hardened, the satisfactory
` condition is obtained.
As explained above, the adhesive~3) stays in filling the
said gap, whereas the group unity of the semilunar-like
! collective group of the adhesive(3) gradually decreases to
change into the convex style and the average prevailing
. areas of the adhesive~3) adjust themselves to transform in
~:.
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` 132978~
accordance with the trans~ormation of the cylinder inside
wall and with that of the skirt portion(21). It is also
understood that the sealing joint section is neither damaged
by an internal pressure change or by the impact load nor the
saaling ability is deteriorated.
Moreover, the adhesive effecting areas between the inner
wall of the cylinder~1) and the skirt portion~21) are larger
in comparison with that of the prior art, and therefore the
sealing ability is far greater.
This embodiment only requires the simple heater
apparatus, which does not affect at all the mass production
system both costly and systematically.
FIG.18 and FIG.19 refer a still further modification of
the invention, which can be applied to any of the
embodiments already described.
`~At the skirt portion(21) of the bottom plate(2~, a recess
or a ditch(27) or plurality of recesses or ditches (2~ at
the fixed interval therearound is established, so that the
adhesive can flow into the curling portion(28) and it is
dryed and hardened.
It i5 recommendable to establish three or four ditches in
the size of 0.1~0.2mm deep and 0.1mm wide. The applicable
~;~adhesive(3) is two-part and non-solvent epoxy type with
2,500~4~000cp viscosity.
In order to flow the adhesive(3) into the curling
portion(28) through the ditch, a 3-minutes heating operation
at 150 degree C is employed or alternatively pressure at
0.5kg/cm2 for half a second is employed.
The adhesive(3) flows into the curling portion(28)
through the ditch~27) and also it fills at the same time the
,,.
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132978~
gap between the inner wall of the cylinder(1) and the skirt
portion(21). Accordingly, it is not necessary to prepare
the slope at the upper part of the skirt portion(21) as
shown in FIG.4. The gap tolerance between the cylinder~1)
and tha skirt portion(21) may be fixed at 0, namely no
tolerance is necessary.
According to this embodiment, the adhesive effective
areas are increased and the airtightness therewith is also
strengthened, wherefore the durability against a shock
caused by the falling and so on is well maintained~
As the curling portion(28) filled with the adhesive
becomes a rigid body completely with the integrity like pure
, metal, a metal container with quite a good sealing is
obtained.
For this embodiment, where the ~steel plate is adopted for
the cylinder(1), the cut edge is completely covered with the
s adhesive(3), which prevents the relative edge from becoming
rusty, and, further, as the curllng portion(28) is filled
with adhesive(3) ,it rejects ~ny incoming of water, and this
s water-proof situation benefits the step of shrink packaging.The shrink film is likely to deform itself by absorbing the
aqueous vapour caused by remaining water therewith. In
general, the aerosol container receives the hot water test
for leakage after refilling, ~nd during this test it is
quite often that the air existing in the gap of the said
curling portion~2B~ comes out to be mistaken as a leakage.
This embodiment definitely avoids such a mistake in the
relative testing procedure.
..
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