U.S. patent application number 11/989613 was filed with the patent office on 2010-01-07 for inmold labeled container and molding process thereof.
Invention is credited to Shinichi Ishiyama, Takao Kurosawa, Takayuki Motegi, Yasuyuki Shimizu.
Application Number | 20100001010 11/989613 |
Document ID | / |
Family ID | 37683141 |
Filed Date | 2010-01-07 |
United States Patent
Application |
20100001010 |
Kind Code |
A1 |
Motegi; Takayuki ; et
al. |
January 7, 2010 |
INMOLD LABELED CONTAINER AND MOLDING PROCESS THEREOF
Abstract
The objects of this invention are to set a predetermined height
position for the portion of parison or preform that is the first to
come in contact with body molding planes of a split mold and to
prevent air from being trapped between in-mold labels and the
container which is blow molded from the parison or the preform.
In-mold labels 7 are fixed to the entire outer surface of body 4 of
main container 1. An annular thinnest wall portion 4a is formed in
the wall of the body 4 so that the thinnest wall portion 4a is the
first to come in contact with the body molding planes 14 of a split
mold 13. Under this construction, no bulge of air is formed between
the body 4 and the in-mold labels 7 fixed to the entire surface of
the body 4.
Inventors: |
Motegi; Takayuki; (Tochigi,
JP) ; Ishiyama; Shinichi; (Tochigi, JP) ;
Kurosawa; Takao; (Tokyo, JP) ; Shimizu; Yasuyuki;
(Tokyo, JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 320850
ALEXANDRIA
VA
22320-4850
US
|
Family ID: |
37683141 |
Appl. No.: |
11/989613 |
Filed: |
June 19, 2006 |
PCT Filed: |
June 19, 2006 |
PCT NO: |
PCT/JP2006/312235 |
371 Date: |
May 7, 2009 |
Current U.S.
Class: |
220/694 ;
264/509 |
Current CPC
Class: |
B29K 2101/00 20130101;
B29C 49/04 20130101; B65D 23/0864 20130101; B29C 2049/2472
20130101; B29B 2911/14326 20130101; B29C 49/2408 20130101; B29C
49/4817 20130101; B29L 2031/712 20130101; B29K 2105/256 20130101;
B29C 49/0078 20130101; B29C 49/06 20130101; B29C 2049/2412
20130101; B29C 49/24 20130101 |
Class at
Publication: |
220/694 ;
264/509 |
International
Class: |
B65D 90/00 20060101
B65D090/00; B29C 49/24 20060101 B29C049/24 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 29, 2005 |
JP |
2005-221841 |
Claims
1. An in-mold labeled container comprising a main container, which
is a blow molded product having a thinnest wall portion annularly
disposed at a middle height of a body, and an in-mold label or
labels firmly fixed to entire outer surface of said body at the
time of blow molding parison into said main containers.
2. The in-mold labeled container according to claim 1 wherein the
in-mold labels are a combination of two labels, each having a
length a half as much as the circumferential length of the
body.
3. The in-mold labeled container according to claim 1 wherein the
in-mold labels are fixed to the body over an entire height range
thereof except for an upper end portion connected to shoulder and a
lower end portion connected to bottom.
4. The in-mold labeled container according to claim 1 wherein the
in-mold labels are fixed to the body, except for the upper end
portion connected to the shoulder and the lower end portion
connected to the bottom, but are separately disposed in an upper
area and a lower area of the body with no labeled area in
between.
5. The in-mold labeled container according to claim 1 wherein
peripheral raised ribs having a maximum outer diameter are disposed
at both ends of the body, i.e., the upper end connected to the
shoulder and the lower end connected to the bottom.
6. The in-mold labeled container according to claim 1 wherein the
in-mold labels are made of synthetic resin film belonging to the
same resin series as that of the main container itself.
7. The in-mold labeled container according to claim 1 wherein the
body has a shape of a straight cylinder.
8. A process for blow-molding an in-mold labeled container having
an in-mold label or labels fixed to entire outer surface of the
body, which process comprises injection molding parison (P) so as
to give a structure in which the parison (P) has an annular thin
wall portion (P1) in a part of the body as a result of wall
thickness control, setting the thin wall portion at a position
opposed to body molding planes of a split mold, pinching the
parison (P) with both halves of the split mold, and blow molding
the parison (P) into the main container.
9. The process for molding an in-mold labeled container according
to claim 8 wherein the parison (P) is pinched with both halves of
the split mold after the in-mold labels have been held in place at
positions opposed to the thin wall portion (P1).
10. The process for molding an in-mold labeled container according
to claim 8 wherein the in-mold labels are held in place in the
split mold by vacuuming all edges of the in-mold labels.
Description
TECHNICAL FIELD
[0001] This invention relates to an in-mold labeled container
having an in-mold label or labels firmly fixed to entire outer
surface of body, and to a molding process thereof,
BACKGROUND ART
[0002] As a means of applying a label bearing a decorative pattern,
a product name, and/or instructions onto the surface of a blow
molded synthetic resin container, there are many types of labels on
which decorative patterns, product names, and/or instructions are
printed, and which are glued on the body surfaces of the
containers.
[0003] These labels to be applied to the containers have excellent
display effects because decorative patterns, product names, and
instructions can be printed favorably on the labels. Since the work
of applying labels to the container body surface is a completely
independent process step, there has to be an additional process of
operation required for the products to be finished. Moreover, these
labels inevitably create slight unevenness or a step between the
body surface and label edges, and this step may have negative
effects on the container appearance and the feel of touch. In
addition, with a trend toward thin wall of the container body,
there were discontent and inconvenience concerning labels because
it becomes more and more difficult to apply labels firmly and
stably to thin body wall.
[0004] As a means of alleviating the discontent and overcoming the
inconvenience, use is made of in-mold labels which are fixed to the
surface of the container body at the same time as the parison is
blow molded into a container.
[0005] This in-mold labeling means achieves the following effects:
Firstly, no independent fixing operation is required because the
in-mold labels are fixed to the container just when the parison is
blow molded into the container. Secondly, there is no step between
the body surface and the in-mold labels, and thus, there is no
possibility that the step may ruin the appearance and the feel of
touch. Thirdly, regardless of thin wall of the container, the
in-mold labels can be fixed to the container firmly and stably.
[0006] Since the in-mold labels can be fixed to the container
firmly and stably, it is possible for the labels to be clad over
the entire surface of the container body, and thereby to have a
favorably wide labeling space. In certain cases, the in-mold labels
reinforce the container body mechanically and effectively. In
addition, the in-mold labels are given a light blocking effect or
an oxygen barrier property so that the container can block the
light or does not allow oxygen to pass through the body wall.
[Patent Document 1] Japanese application No. 2006-064029
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0007] However, as the in-mold labels became larger and larger and
clad over the entire body surface of the container, there has
arisen a problem in the above-described technology. With an
exception of the in-mold labels made of cardboard and having air
permeability, there occurred air trapping between the container and
the large-size in-mold label. Such trapped air inhibited firm
fixing of the labels to the container, and bulges of trapped air
gave damage to the appearance of the container.
[0008] Especially in the cases where the in-mold labels are clad
around, and fixed to, the entire outer surface of the container
body, the air existing between the in-mold label and the widening
and extending parison or preform tends to escape in the
circumferential direction and to cause air trapping to occur.
[0009] This invention has been made to solve the above-described
problems found in conventional art. The technical problem of this
invention is that, when the parison or the preform is blow molded
into the container of this invention, a roughly constant,
predetermined height position is set for the portion of parison or
preform that is the first to come in contact with the body molding
plane of the clamped split mold where the in-mold labels are held
in place. The object of this invention is to prevent air from being
trapped between the in-mold labels and the container which has been
blow molded from the parison or the preform.
Means of Solving the Problems
[0010] The means of carrying out the invention of claim 1 to solve
the above-described technical problems is that the blow molded
container is provided with an annular thinnest wall portion which
is disposed at the middle height of the body and that in-mold
labels are fixed to the entire outer surface of the body of the
main container when the container is blow molded from parison.
[0011] When the thinnest wall portion comes in contact with the
body molding plane in earlier times, there may be a time lag of
contact, depending on the positions of the thinnest wall portion
along the circumference. In those positions, contact may be
somewhat delayed. In the invention of claim 1, trapped air in those
positions opposed to the thinnest wall portion, where contact is
delayed, can escape smoothly and spontaneously in the upward or
downward direction, and no bulge of trapped air is formed. This is
because, even if the contact is delayed, the thinnest wall portion
is always the first portion of the body that comes in contact with
the body molding planes.
[0012] Since the thinnest wall portion is disposed around the body
at its middle height, this height position can be precisely
determined according to that of the in-molds label held on the body
molding planes of the split mold.
[0013] For the wall portions of the body other than the thinnest
wall portion, contact come later, starting from the areas closest
to the thinnest portion and spreading to remote areas. Thus, the
bulges of air trapped between these other portions and the body
molding planes are pushed out, one by one, by the behavior of these
other portions steadily and spontaneously in the upward or downward
direction.
[0014] The invention of claim 2 comprises that, under the
construction of the invention of claim 1, the in-mold labels are a
combination of two labels, each having a length a half as much as
the circumferential length of the body.
[0015] In the invention of claim 2, the respective length of the
two labels in the circumferential direction never becomes larger
than the circumferential length of the body molding plane of each
split mold half. Thus, each mold half can hold a half-length
in-mold label without allowing the label to extend beyond the range
of the body molding plane of each mold half.
[0016] The invention of claim 3 comprises that, under the
construction of the invention of claim 1 or 2, the in-mold labels
are fixed to the body over an entire height range thereof except
for an upper end portion connected to shoulder and a lower end
portion connected to bottom.
[0017] In the invention of claim 3, both of upper and lower edges
of in-mold labels need not be located in the portions of the body
where outer diameter is changed. Therefore, these upper and lower
edges can be fixed strongly to, and held stably on, the container.
These in-mold labels provide a wide range of display area from
bottom to shoulder.
[0018] The invention of claim 4 comprises that, under the
construction of the invention of claim 1 or 2, the in-mold labels
are fixed to the body (4), except for the upper end portion
connected to the shoulder and the lower end portion connected to
the bottom, but are disposed separately in an upper area and a
lower area of the body with no labeled area in between.
[0019] In the invention of claim 4, there can be different displays
for the upper area and the lower area of the body.
[0020] The invention of claim 5 comprises that, under the
construction of the invention of either one of claims 1 to 4,
peripheral raised ribs having a maximum outer diameter are disposed
at both ends of the body, i.e., the upper end connected to the
shoulder and the lower end connected to the bottom.
[0021] In the invention of claim 5, mechanical strength of the body
can be increased because the peripheral raised ribs serve as
reinforcing ribs. If in-mold labels are fixed to the entire height
range of the body excluding these peripheral raised ribs, the upper
and lower edges of each in-mold label rest at the bases of these
ribs. Since the peripheral raised ribs have a maximum outer
diameter, these ribs protect the in-mold labels against careless
contact with other containers in cases of handling many containers
packed side by side. In addition, with the help of these ribs, the
in-mold labels are fixed to the container at precisely located
positions of the body surface.
[0022] The invention of claim 6 comprises that, under the
construction of the invention of either one of claims 1 to 5, the
in-mold labels are made of synthetic resin film belonging to the
same series of resins as that of the main container itself (1).
[0023] In the invention of claim 6, there is no need of handling
in-mold labels separately from containers in waste disposal and
recycling of containers. It is also possible to obtain strong
fixation between the body and the in-mold labels.
[0024] The invention of claim 7 comprises that, under the
construction of the invention of claims 1 to 6, the body has a
shape of a straight cylinder.
[0025] In the invention of claim 7, the body has a uniform outer
diameter over the entire height range. Therefore, the thinnest wall
portion of the blow molded body can be molded accurately and
stably. Since the outer surface of the body is a primary curved
surface, the in-mold labels can be fixed in an appropriate
configuration.
[0026] The means of carrying out the invention of claim 8 to solve
the above-described technical problems is a process for
blow-molding parison into an in-mold labeled container having an
in-mold label or labels fixed to the entire outer surface of the
body. This process comprises injection molding parison (P) so as to
give a structure in which the parison (P) has an annular thin wall
portion (P1) in a part of the body (4) as a result of wall
thickness control, setting the thin wall portion at a position
opposed to body molding planes of a split mold, pinching the
parison with both halves of the split mold, and blow molding the
parison into the container.
[0027] In the invention of claim 8, an easily deformable thin wall
portion tends to widen and extend more quickly than other portions
do because of minimum thickness, and comes in earliest contact with
the body molding planes of the split mold that holds the in-mold
labels in place. Then, the other portions come in contact in
sequence, starting from the portions closest to the thin wall
portion and spreading to remote areas.
[0028] When the thin wall portion of parison comes in contact with
body molding planes in earlier times, there may be more or less a
time lag of contact, depending on the positions of the thin wall
portion along the circumference, and contact may happen to be
somewhat delayed in these positions. However, the thin wall portion
is always the first portion of the body that comes in contact with
the body molding planes, as compared with the areas on the upside
and downside of the thin wall portion, where contact comes later.
Therefore, trapped air in those positions opposed to the thin wall
portion, if any, can escape smoothly and spontaneously in the
upward or downward direction, and no bulge of air is formed.
[0029] For the portions of parison other than the thin wall
portion, contact with the body molding planes shifts from the area
closest to the thin portion to remote areas, while pushing out
bulges of air between the body wall and the body molding
planes.
[0030] The invention of claim 9 comprises that, under the
construction of the invention of claim 8, the parison is pinched
with both halves of the split mold after the in-mold labels have
been held in place at positions opposed to the thin wall
portion.
[0031] In the invention of claim 9, a part of each in-mold label is
pushed by the thin wall portion of the parison against the body
molding planes of a split mold, whereby the position of the thin
wall portion is set down. Starting from this fixed position of the
thin wall portion, the expanding parison continues to push other
parts of the in-mold labels against the body molding planes. In
this manner, the in-mold labels can stably maintain the precisely
positioned contact with the body molding planes.
[0032] The invention of claim 10 comprises that, under the
construction of the invention of claim 8 or 9, the in-mold labels
are held in place in the split mold by vacuuming all edges of the
in-mold labels.
[0033] In the invention of claim 10, the in-mold labels, which are
longer in the circumferential direction than in the vertical
direction, are precisely positioned for all the edges, and in such
a state, are maintained in contact with the body molding planes of
the split mold. Therefore, the in-mold labels are held in place
easily and precisely with a posture in which they are to be fixed
to the blow molded body.
Effects of the Invention
[0034] This invention having the above-described construction has
the following effects:
According to the invention of claim 1, the body comprises a
thinnest wall portion and other portions. Since the thinnest wall
portion and other portions are different in the timing of contact
with the body molding planes, no bulge of air is formed between the
blow molded body and the in-mold labels. As a result, the in-mold
labels are fixed to the body strongly and stably, and the container
can maintain a good shape which has not been degraded by bulges of
air.
[0035] The height position of the thinnest wall portion of the body
can be accurately determined so that this portion is disposed at
right positions opposed to the in-mold labels held on the body
molding planes of the split mold. It is also possible to govern the
behavior of the body and set the timing of contact in advance
almost accurately when the body expanding in the process of blow
molding pushes the in-mold labels against the body molding planes.
Therefore, the in-mold labels can be fixed properly to the
body.
[0036] According to the invention of claim 2, the in-mold labels
can be held at right positions opposed to the body molding planes
of the split mold. Since the in-mold labels can be held in place by
the split mold safely in high precision, the in-mold labels are
fixed around the entire outer surface of the body, and this
structure of labels on the body can be obtained easily and
reasonably.
[0037] According to the invention of claim 3, the container has a
high decorative effect because almost entire outer surface of the
body is clad with the in-mold labels. This decorative effect can be
fulfilled when the almost entire surface of the body is used as a
display area once the in-mold labels have been firmly fixed to the
body. The in-mold labels covering almost entire outer surface of
the body can also be utilized as a reinforcing material for the
body, thus allowing containers to have thinner wall.
[0038] According to the invention of claim 4, there can be
different displays of in-mold labels for the upper area and the
lower area of the body. This configuration gives the container
large changes in the decorative displays by means of the in-mold
labels. For instance, highly distinctive, individualized
decorations can be displayed.
[0039] According to the invention of claim 5, the peripheral raised
ribs enhance mechanical strength of the body. In addition, since
the in-mold labels are fixed firmly to the body, the mechanical
strength of the body equipped with in-mold labels can be fully
increased. These peripheral ribs are also useful to protect the
decorative displays of the in-mold labels indirectly. This effect
is notably achieved if the body has a straight cylindrical
shape.
[0040] According to claim 6, there is no need of handling in-mold
labels separately from containers in waste disposal. Therefore,
container handling will become quite easy in the withdrawal of used
containers and the recycling of materials. Since firm fitting of
the body to the in-mold labels can be readily obtained, the in-mold
labeled containers of high quality are available.
[0041] According to the invention of claim 7, it is possible to
mold the preceding body portion with ease and precision when this
portion is first molded. Since the outer surface of the body is a
primary curved surface, the in-mold labels can be fixed in an
appropriate configuration. Thus, favorable in-mold labeled body can
be obtained in an assured way.
[0042] According to the invention of claim 8, the thin wall portion
of the parison is blow molded stably and steadily into the
corresponding thinnest wall portion of the body, thus ensuring that
the body comprising the thinnest wall portion and other portions is
molded without fail.
[0043] Since the thinnest wall portion of the body can be molded
without fail, the container is naturally protected from bulges of
air that are formed between the body and the in-mold labels. The
in-mold labeled body having high mechanical strength and good shape
can be molded by utilizing the thinnest wall portion.
[0044] According to the invention of claim 9, the in-mold labels
held in place by the split mold are prevented from wrong
displacement because the thin wall portion of the parison ensures
that the in-mold labels can stably maintain the precisely
positioned contact with the body molding planes of the split
mold.
[0045] According to the invention of claim 10, the in-mold labels
can be fixed properly to the body molding planes of the split mold
with ease and precision. As a result, any inconveniences, such as
overlapped edges of the in-mold labels or the edges pinched between
two halves of the split mold, can be safely prevented from
occurring. The in-mold labeled container can be molded precisely
and stably.
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] FIG. 1 is a front elevational view of the container in the
first embodiment of this invention, with right half being
illustrated in a vertical section.
[0047] FIG. 2 is an enlarged cross-sectional plan view of the
container of FIG. 1, taken from line A-A.
[0048] FIG. 3 is an exploded perspective view of the container in
the second embodiment of this invention.
[0049] FIG. 4 is a front elevational view of the container in the
second embodiment of this invention shown in FIG. 3, with right
half being illustrated in a vertical section.
[0050] FIG. 5 is a front elevational view of the container in the
third embodiment of this invention, with right half being
illustrated in a vertical section.
[0051] FIG. 6 is a front elevational view of the container in the
fourth embodiment of this invention, with right half being
illustrated in a vertical section.
[0052] FIG. 7 is a vertical section showing an exemplified
structure of the split mold for molding the container of this
invention.
[0053] FIG. 8 is a development showing an exemplified structure of
the body molding plane for use in the split mold shown in FIG.
7.
[0054] FIG. 9 is an explanatory diagram showing blow molding
behavior displayed in the molding process of this invention.
EXPLANATION OF CODES
[0055] 1. Main container [0056] 2. Neck [0057] 3. Shoulder [0058]
4. Cylindrical body [0059] 4a. Thinnest wall portion [0060] 5.
Peripheral raised rib [0061] 6. Bottom [0062] 7. In-mold label
[0063] 7a. Butting edge [0064] 7b. Gap [0065] 8. Cap [0066] 9.
Fitting cylinder [0067] 10. Top plate [0068] 11. Hinge [0069] 12.
Lid [0070] 13. Split mold [0071] 14. Body molding plane [0072] 15.
Vacuum hole [0073] 16. Nested block [0074] 17. Vacuum channel
[0075] 18. Pinch-off section [0076] 19. Blow jig [0077] P. Parison
[0078] P1. Thin wall portion
PREFERRED EMBODIMENTS OF THE INVENTION
[0079] This invention is further described with respect to
preferred embodiments, now referring to the drawings.
[0080] FIG. 1 is a front elevational view of the container in the
first embodiment of this invention, with the right half shown in a
vertical section. This container comprises a main container 1,
which is a blow molded product made of a synthetic resin, and
in-mold labels 7 clad around, and fixed to, outer surface of a body
4 of the main container 1. This main container 1 comprises the
cylindrical body 4 in the shape of a straight cylinder, a bottom 6
dented slightly inward in a spherical arc to close the body 4, a
shoulder 3 which is an inward step from upper end of the body 4,
and a cylindrical neck 2 having a diameter shorter than that of the
body 4 and also having a screw thread notched around the outer
surface.
[0081] In the first embodiment of this invention, the body 4 of the
main container 1 is disposed between the shoulder 3 and the bottom
6, and comprises a thinnest wall portion 4a and other portions. The
thinnest wall portion 4a is the first to come in contact with the
body molding planes 14 of a split mold 13, which is a blow mold.
For other wall portions having thicker wall, contact comes later,
starting from areas closest to the thinnest wall portion 4a, and
spreading to remote areas.
[0082] The in-mold labels 7 to be fixed to outer surface of this
body 4 are made of a synthetic resin film in the same series of the
synthetic resin used to mold the main container 1. These labels are
fixed to the body 4 over the entire height range thereof, excluding
the upper end portion connected to the shoulder 3 and the lower end
portion connected to the bottom 6, and to the entire outer surface
of the body 4. The in-mold labels 7 are a combination of two
in-mold labels having the same height and the same peripheral
length.
[0083] When the in-mold labels 7 comprising a pair of in-mold
labels are fixed to the outer surface of the body 4, the two labels
make an end-to-end contact at a butting edge portion 7a on one
side, while on the other side, a slight gap 7b in the range of 0.5
to 1 mm is left between two vertical edges so that both edges face
each other beyond this gap.
[0084] Thus, the gap 7b is prepared between two vertical edges of
the two in-mold labels 7 on the other side of the connection
between two in-mold labels 7. This gap serves to prevent the
vertical edges from being overlapped with each other. The
circumferential length of the two in-mold labels 7 is set so as to
have a length shorter than the counterpart of the body molding
plane 14 (See FIG. 7) of the split mold 13 by a value corresponding
to a maximum level (about 0.5 mm) of metrication error that is
likely to occur. Though the gap 7b may remain, it ensures that the
vertical edges of the in-mold labels 7 are protected against
overlapping.
[0085] If overlapping occurred between the two edges of the two
in-mold labels 7 on one side of the connection, the edge portion on
top of the other edge would tend to be peeled easily. Once this
occurs, it is very likely that this peeling develops further until
this in-mold label 7 would peel from the body 4.
[0086] FIG. 3 is an exploded perspective view of the container in
the second embodiment of this invention, to which a cap 8 is to be
fitted so that the container can be utilized as a caster to shake
the contents out of the container. As shown in FIG. 4, the main
container 1 has the same construction as the first embodiment,
except that portions having the largest outer diameter are disposed
at upper and lower ends of the body 4 and that peripheral raised
ribs are disposed in those upper and lower portions so that upper
and lower edges of the in-mold labels 7 can rest at the bases of
these ribs.
[0087] In this second embodiment, the container has a stable
shape-retaining ability because the peripheral raised ribs 5 serve
as reinforcing ribs. The peripheral raised ribs 5 have the largest
outer diameter, as compared to other portions of the main container
1, and stabilize the container posture when many containers stand
side by side. As a result, the containers can be handled in good
conditions during storage or transportation. During the time when
the containers are handled, the ribs protect the in-mold labels 7
fixed to outer surface of the body so that the labels 7 may not by
accident come in contact with other containers or objects.
[0088] The cap 8 is fitted to the container in the second
embodiment of this invention so that the container is utilized as a
caster. This cap 8 comprises a fitting cylinder 9 which is fitted
around the neck 2 by screw engagement, a top plate 10 disposed at
the upper end of the fitting cylinder 9 to close roughly a half of
the upper opening, and a lid 12 in a semi-circular shape, which is
connected to a straight edge of the top plate 10 on the opening
side of the fitting cylinder 9 by way of a hinge in a swingable
manner and is provided with a skirt segment hanging from the lid 12
along its semi-circular edge.
[0089] The cap fitted to the main container 1 is not limited to the
illustrated one for caster use, but any desired cap, such as an
ordinary removable cap or a dischargeable cap, can be fitted.
[0090] FIG. 5 shows the container in the third embodiment of this
invention. In this embodiment, the in-mold labels are fixed to only
a middle area of the body, in a position somewhat closer to the
shoulder than to the bottom, but are under the same construction as
in the first embodiment for other portions.
[0091] In the case of the third embodiment, the thinnest wall
portion 4a is in the position opposed to the in-mold labels 7. A
combination of the main container 1 and the in-mold labels 7
creates a decorative effect on the container.
[0092] FIG. 6 shows the container in the fourth embodiment of this
invention, in which the in-mold labels 7 are fixed to the body 4,
excluding the upper end portion connected to the shoulder 3 and the
lower end portion connected to the bottom 6, but are disposed
separately in an upper area and a lower area of the body 4 with no
labeled area in between. Other than this configuration, the
container has the same construction as the first embodiment.
[0093] In this fourth embodiment, the thinnest wall portion 4a of
the body 4 is disposed in a space between a portion opposed to
upper in-mold labels 7 and a portion opposed to lower in-mold
labels 7. Under this construction, the behavior of parison P (See
FIG. 9) in the blow molding operation would have a uniform effect
on the two pairs of in-mold labels 7. Since two pairs of upper and
lower in-mold labels 7 are used to display the container, it is
possible to make the container display fresh and varied.
[0094] FIG. 7 is a vertical section of an important part of a pair
of halves of the split mold 13 used to mold the container in the
second embodiment of this invention. The split mold 13 has a
pinch-off section 18 under the container cavity, and nested blocks
16 are combined with the split mold 13 and are used as the body
molding planes 14. FIG. 8 is a development of a body molding plane.
As shown, a slit-like endless vacuum hole 15 in a square shape is
open along the four sides of each body molding plane. Vacuum
channels 17 are also disposed in the split mold 13.
[0095] Under this construction, the in-mold labels 7 can be held by
vacuum in tight contact with the body molding planes 14 because the
in-mold labels 7 are held in place by vacuum along the entire
circumference of the labels 7. Since vacuum holes 15 are formed
along the vertical edges of each body molding plane, the in-mold
labels 7 are naturally held in place in a precisely positioned
state.
[0096] When the container is blow molded in the split mold 13 shown
in FIG. 7, the in-mold labels 7 are positioned by means of a robot
and the like in the open split mold 13, and are held in contact
with the body molding planes 14 by vacuuming the body molding
planes through the vacuum holes 15.
[0097] The parison P is extrusion molded by an extruder (not shown)
and is pinched by both halves of the split mold 13. Since an
annular thin wall portion P1 has been molded in a part of the
parison under the wall thickness control at the time of extrusion
molding, the parison P is pinched at right timing when this thin
wall portion P1 has come to face a desired position of the body
molding planes 14 (See the parison in solid lines in FIG. 9).
[0098] After the parison P has been pinched with both halves of the
split mold 13 and cut off at the pinch-off section, a blow jig 19
is fitted to the split mold 13, and the pinched parison P is blow
molded into the main container 1, following an ordinary blow
molding procedure.
[0099] When the parison P is blow molded into the main container 1,
the thin wall portion P1 of the parison is the first to widen and
expand, as shown by chain two-dashed lines, because P1 is easier to
expand than the rest of the parison. Thus, the thin wall portion P1
quickly comes in contact with the in-mold labels 7 that are held in
place, and is molded into the thinnest wall portion 4a of the body
4.
[0100] As the blow molding of the parison P goes on in this state,
portions of the parison P, other than the thin wall portion, come
in contact with the in-mold labels 7, starting from the areas
closest to the thin wall portion and spreading to remote areas, and
are molded into other portions of the body 4.
[0101] For the portions of the parison P that are molded into other
portions of the body 4, contact with the in-mold labels 7 comes
later, starting from the areas closest to the thin wall portion P1
and spreading to remote areas. Since at the time of contact, bulges
of air trapped between the in-mold labels 7 and the parison P are
pushed out, no bulge of air is formed between the in-mold labels 7
and the body 4 molded from the parison P.
[0102] The in-mold labels 7 can be fixed to the body 4 of the blow
molded container at the same time as the blow molding of the main
container 1, by a thermal adhesion means utilizing the heat of
parison P or by a pressure adhesion means utilizing a blow molding
pressure.
[0103] In the foregoing description of this invention, blow molding
was used as an example. However, means of carrying out this
invention is not limited to blow molding, but can be applied also
to biaxial drawing and blow molding.
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