U.S. patent application number 10/573013 was filed with the patent office on 2007-03-29 for plastic bottles.
Invention is credited to Osamu Aoyagi, Hiromasa Iwashita, Kenshi Matsuoka.
Application Number | 20070068894 10/573013 |
Document ID | / |
Family ID | 34419299 |
Filed Date | 2007-03-29 |
United States Patent
Application |
20070068894 |
Kind Code |
A1 |
Iwashita; Hiromasa ; et
al. |
March 29, 2007 |
Plastic bottles
Abstract
Plastic bottles (1) which are characterized in that: they are
composed of neck (2), shoulder (3), body (4) and bottom (5); the
cross-sectional shape at the body (3) is a regular polygon, the
number of angles of which is an even number of not less than 4 nor
more than 32; each angle of the polygon is rounded off by an arc
(8) whose radius is not longer than half the radius of a circle
circumscribed about the cross-sectional shape at body (3);
cross-sectional shapes have the same shape at any portion of body
(3); circles circumscribed about the cross-sectional shapes are
identical with one another; the circumscribed circles have a center
on the vertical central axis of body (3); and the cross-sectional
shape of body (3) rotates around said central axis in proportion to
height along said central axis.
Inventors: |
Iwashita; Hiromasa; (Tokyo,
JP) ; Aoyagi; Osamu; (Tokyo, JP) ; Matsuoka;
Kenshi; (Tokyo, JP) |
Correspondence
Address: |
SUTHERLAND ASBILL & BRENNAN LLP
999 PEACHTREE STREET, N.E.
ATLANTA
GA
30309
US
|
Family ID: |
34419299 |
Appl. No.: |
10/573013 |
Filed: |
September 30, 2004 |
PCT Filed: |
September 30, 2004 |
PCT NO: |
PCT/JP04/14813 |
371 Date: |
March 22, 2006 |
Current U.S.
Class: |
215/382 ;
215/379 |
Current CPC
Class: |
B65D 1/0223 20130101;
B29C 49/08 20130101; B29B 2911/14466 20130101; B29K 2023/12
20130101; B29C 49/06 20130101; B29B 2911/1444 20130101; B29K
2023/06 20130101; B65D 2501/0018 20130101; B29C 49/0073 20130101;
B29K 2067/00 20130101 |
Class at
Publication: |
215/382 ;
215/379 |
International
Class: |
B65D 90/02 20060101
B65D090/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 1, 2003 |
JP |
2003-343481 |
Claims
1. Plastic bottles which are characterized in that: they are
composed of a neck, a shoulder, a body and a bottom; a
cross-sectional shape at the body is a regular polygon, the number
of angles of which is an even number of not less than 4 nor more
than 32; each angle of the polygon is rounded off by an arc whose
radius is not longer than half the radius of a circle circumscribed
about the cross-sectional shape at the body; the cross-sectional
shapes have the same shape at any portion of the body; the circles
circumscribed about the cross-sectional shapes are identical with
one another; the circumscribed circles have a center on the
vertical central axis of the body; and the cross-sectional shape of
the body rotates around said central axis in proportion to a height
along said central axis.
2. Plastic bottles of claim 1 wherein the cross-sectional shape at
the body rotates, the relation between rotation angle and height
being 1.degree./mm or less.
3. Plastic bottles of claim 1 wherein the cross-sectional shape at
the body rotates to make a rotation angle of 360.degree./the number
of angles in the polygon.
4. Plastic bottles of claim 1 wherein also the cross-sectional
shape at the shoulder is a polygon whose angles are each rounded
off by an arc, and wherein the cross-sectional shape is not
rotated.
5. Plastic bottles of claim 1 which are made from plyethylene
terephthalate, and have been molded by biaxial stretch
blow-molding.
Description
TECHNICAL FIELD
[0001] This invention relates to plastic bottles to be used as
liquid containers, more specifically to plastic bottles for
beverages which are to be hot-filled or aseptic-filled.
BACKGROUND ART
[0002] Biaxially stretched blow-molded bottles made from
polyethylene terephthalate (PET) are widely used as beverage
containers. Containers are usually filled with beverage product
either by hot-filling or by aseptic-filling. In hot-filling,
biaxially stretched blow-molded containers are filled with beverage
which has been heated to around 90.degree. C., sealed with a cap,
and are then cooled. In aseptic-filling, containers are sterilized,
and are then filled in the resultant aseptic environment.
Hot-filling has been accompanied with a problem that containers
expand when filled or capped, and that, when cooled, containers
shrink due to reduced pressure inside. Also aseptic-filling has had
a problem that containers shrink due to reduced pressure which is
caused by the contents' absorbing oxygen in the head space.
[0003] In recent years, these PET bottles are often displayed in a
warmed showcase. This causes a problem that containers swell due to
increased internal pressure when warmed.
[0004] As a solution to the above-mentioned problems, bottles are
usually provided, on their body, with an absorption panel or
concave ribs which swell when the bottle expands and shrink when
the bottle is decompressed, and thus absorb deformation. In another
solution, the amount of material resin is increased by which to
enhance the rigidity of bottles. These approaches require a large
absorption panel, which compromises the appearance of bottle. Also
from the viewpoint of overall design, these bottles lack continuity
in outline, and therefore look awkward.
[0005] In addition, absorption panels have a concave-convex shape.
Hence, when shrink-label is put on bottle for surface decoration,
gaps can be made between the bottle and the shrink-label to cause a
problem that bottle becomes difficult to handle, that shrink-label
is torn during transportation, and that moisture which has been
trapped in these gaps is difficult to be removed.
[0006] If no heat insulation panel is used so that the bottle may
have a cylindrical shape by which to avoid the above-mentioned
problems, bottles shrink unevenly when decompressed, compromising
their appearance. Besides, if the amount of material resin of
bottle is reduced, longitudinal buckling strength is decreased,
and, therefore, bottles crush when stacked. Due to these problems,
the only realistic way to make bottles withstand decompression has
been to increase the amount of material resin of bottle, which is
undesirable from the viewpoint of productivity and economy.
[0007] Another possible solution is a polygonal bottle as shown in
Japanese Design Registration No. 935840. This solution has a
problem that bottles of this shape has low strength due to the lack
of heat insulation panel. Hence, each face which constitutes side
wall is deflected in vertical direction under reduced pressure,
resulting in conspicuous deformation. Otherwise, portions with a
small wall-thickness give way under reduced pressure, and, thus,
only the faces of those portions are buckled to exhibit remarkable
deformation.
[0008] In the bottles as shown in Japanese Design Registration No.
961967, triangular faces are arranged geometrically and on upper
and lower parts of twisted wall, which structure serves to give
strong bottles. Besides, vertical section (side wall) has a
terraced shape with a recession, which also contributes to
strength. Each of the twisted side faces resists deformation as a
result of the above-mentioned structure, which also serves to
strengthen the bottle. Hence, the shape of bottle as disclosed in
Japanese Design Registration No. 961967 is appropriately designed
to increase bottle strength (enhance the rigidity of container).
When reduced pressure is applied to bottle, however, high rigidity
may give rise to buckling in thin areas alone, which leads to
severe deformation. Furthermore, since vertical section has a
terraced shape where triangular faces are complicatedly arranged,
there is a concern that, in an sterilization step of aseptic
filling, the flow of sterilizing liquid may be insufficient in some
areas, or that the liquid may be incompletely rinsed away.
[0009] Moreover, the shape of bottles has so far been restricted to
stereotype such as cylindrical or square to ensure fast and
reliable feeding of bottles on beverage production lines, and
especially to ensure that bottles do not tumble down when slid and
fed on continuous production lines, and also to make it easy to
pack bottles neatly in casers.
DISCLOSURE OF INVENTION
[0010] In order to resolve the above-mentioned problems with
conventional bottles, this invention is to provide, at a low price,
plastic beverage bottles which, in aseptic-filling and hot-filling,
are not deformed awkwardly by the change in internal pressure which
is caused by warming or cooling, are capable of absorbing
decompressed volume, are so well-designed as to avoid poor
appearance, and are easy for consumers to handle, free from tearing
or peeling of shrink-labels during transportation, have high load
capacity strength and horizontal compression strength as well as
package strength, and bring no problem in bottle-filling line.
[0011] To satisfy the above-mentioned objective, the plastic
bottles of this invention are characterized in that: they are
composed of neck, shoulder, body and bottom; the cross-sectional
shape at the body is a regular polygon, whose angles have an even
number of not less than 4 nor more than 32; each angle of the
polygon is rounded off by an arc whose radius is not longer than
half the radius of a circle circumscribed about the cross-sectional
shape at body; cross-sectional shapes are the same at any portion
of body; circles circumscribed about the cross-sectional shapes are
identical with one another; the circumscribed circles have a center
on the vertical central axis of body; and the cross-sectional shape
of body rotates around said central axis in proportion to height
along said central axis.
[0012] In a preferred embodiment of the above-mentioned plastic
bottles, the cross-section of body rotates to make a rotation angle
of 360.degree./the number of angles in the polygon.
[0013] In another preferred embodiment of the above-mentioned
plastic bottles, cross-section at shoulder is also a polygon
wherein each angle thereof is rounded off by a circular arc, and
said cross-section does not rotate.
[0014] In another preferred embodiment of the above-mentioned
plastic bottles, the plastic bottle is made from polyethylene
terephthalate, and is molded by biaxial stretch blow molding.
[0015] A bottle which has been manufactured under these conditions
has a wall-side of a shape of twisted regular polyhedron from
bottom to shoulder. When this container is decompressed, each face
is decompressed while the container as a whole neutralizes
deformation caused by the decompression, in the direction of the
twist. Thus, although deformation takes place, it is not
conspicuous as compared with the shape of container before
deformation. With regard to strength of resistance to decompression
induced by deformation, the bottle deforms as a whole so that
deformation may be neutralized, and, therefore, remarkable
deformation such as so-called buckling is hard to occur. Thus, the
bottle of this invention can be said to be stronger against
decompression than conventional bottles, in view of the concept of
"remarkable deformation which affects the acceptability of
products". It may be said that the bottle of this invention
breathes in accordance with change in internal pressure. It has
been confirmed that, on the afore-mentioned accounts, even though
severe deformation like buckling occurs, the bottle returns to the
original shape as soon as decompression is eased, unlike
conventional bottles reinforced with panels that do not return to
their original shapes.
[0016] This invention provides plastic beverage bottles which, in
aseptic-filling and hot-filling, are not deformed awkwardly by the
change in internal pressure which is caused by warming or cooling,
are so well-designed as to avoid poor appearance, and are easy for
consumers to handle, free from peeling of shrink-labels during
transportation, have high load capacity strength, and bring no
problem in bottle-filling line.
[0017] In conventional plastic bottles, when internal pressure
changes, central axis of neck section leans out of the central axis
of body of the bottle, and, thus, deformation occurs. In the bottle
of this invention, plural numbers of helixes are wound tighter
around the body, with the result that the height of plastic bottle
decreases, and, accordingly, volume is decreased. Or, on the
contrary, plural numbers of helixes are wound more loosely, with
the result that the height of plastic increases, and, accordingly,
volume is increased. Such deformation prevents the plastic bottle
of this invention from deforming in such a way that the central
axis of its neck section leans out of central axis of body
section.
BRIEF DESCRIPTION OF DRAWINGS
[0018] FIG. 1: Schematic drawing of an embodiment of this
invention
[0019] FIG. 2: Cross-section of the body of bottle of an embodiment
of the invention
[0020] FIG. 3: Cross-section of the body of bottle of an embodiment
of the invention
BEST MODE FOR CARRYING OUT THE INVENTION
[0021] FIG. 1 illustrates an embodiment of this invention. The
plastic bottle (1) of this invention is comprised of neck (2),
shoulder (3), body (4), and bottom (5), and the bottle (1) is to be
sealed with a closure (6). As closure (6), anything can be
acceptable so long as it ensures a secure seal. Examples of
closures include screw caps, push caps, and heat-sealing, among
which screw cap is preferable in view of re-capping after
opened.
[0022] As the material of plastic bottle, polypropylene,
polyethylene, polyamide, polyethylene terephthalate, and laminate
thereof are thinkable. Anything of these is allowable so long as it
is capable of forming a desired bottle shape. In view of use for
beverage, biaxially stretched blow-molded bottles made from
polyethylene terephthalate are preferable.
[0023] Cross section (7) at the body of this plastic bottle (1) is
regular polygon, wherein each angle is rounded off by arc (8). Any
section has the same shape between the lower end (9) and the top
end (10) of the body of plastic bottle. Owing to this feature, no
concave is made on the body. Hence, when shrink label is placed as
a surface decoration, there is made no gap between the bottle and
the label, and, thus, label is prevented from peeled or torn during
distribution, and, moreover, water is prevented from collecting
between the bottle and the label. The absence of gap between the
shrink label and the bottle gives consumers a better handling.
[0024] The bottle of this invention is further characterized in
that any circle (11) circumscribed about the cross-section at the
body has the same shape, and that the centers (12) of such
circumscribed circles are placed on the same axis.
[0025] The number of angles of the regular polygon is preferably an
even number between four and 32. If the number of angles is more
than 32, the external shape becomes indistinguishable from that of
a cylindrical bottle. Six or eight is desirable from the viewpoint
of designing. If the number of angles is odd, wall thickness
becomes non-uniform when bottle is blown-up. Furthermore, split
line of blow-mold may become complicated, and scratch may occur
when bottle is taken out of the mold.
[0026] Each angle of the polygon at body is rounded off by a
circular arc (8) whose radius is not longer than half the radius of
a circle (11) circumscribed about the cross-section of the body.
This feature not only leads to excellent design, serving to give a
beautiful expression of polygonal surfaces, but also produces
ribbing effects when the radius of arc (8) is small, which effects
enhance resistance to vertical loading.
[0027] Any section has the same shape between the lower end (9) and
the top end (10) of the body of plastic bottle. Furthermore, any
circle (11) circumscribed about the cross-section at the body has
the same shape, and the centers (12) of such circumscribed circles
are placed on the same axis. Owing to these features, bottles are
less likely to become jammed on the production line.
[0028] Cross-section at the body is rotated around the center (12)
of circle circumscribed about the cross-section at the body, and in
proportion to height. This feature achieves flowing outline
together with improved resistance to horizontal load. Due to this
rotation, contact surfaces of bottle come near to circular shape,
which improves rolling property. This also makes it easy to charge
a vending machine with bottles.
[0029] Also with regard to change in internal volume which has been
a technical problem, bottles are expanded or contracted in vertical
direction owing to rotation, and are thus allowed to deform without
damaging appearance. As for the relation between angle of the
rotation of cross-sectional shape at body and height, it is
preferably 0.6.degree./mm or less, or, more desirably,
360.degree./number of angles. When rotation angle is too large in
relation to height, the undercut of mold becomes large, which
causes a problem that it becomes difficult to draw bottles from the
mold in blow molding, and that scratches occur when bottles are
drawn from mold. When the rotation angle is 360.degree./number of
angles, there occurs no problem of undercut, and bottles are molded
without any problem.
[0030] With respect to bottle design, also cross-sectional shape at
shoulder may be a polygon whose angles are each rounded off by an
arc, for the purpose of emphasizing the streamline image much more.
In that case, it is preferable not to rotate the cross-sectional
shape so as to avoid undercut problem.
EXAMPLE
[0031] An embodiment of the above-mentioned invention is explained
by a working example as follows.
[0032] A bottle was manufactured by biaxial stretching blow-molding
with use of polyethylene terephthalate. Material resin was used in
an amount of 29 g, capacity was 500 ml, maximum diameter was 67 mm,
and height was 207 mm. The bottle was composed of neck, shoulder,
body and bottom. The cross-sectional shape at the body was a
regular hexagon. Each angle of the regular hexagon was rounded off
with an arc. Cross-sections had the same shape at any portion of
body. Circles circumscribed about the cross sectional shape were
identical. The centers of the circumscribed circles were on the
same axis. The circumscribed circle had a radius of 33.5 mm. The
arc had a radius of 5 mm.
[0033] Cross sectional shape at body was rotated uniformly at a
rate of 0.4.degree./mm around the center, as axis, of circles
circumscribed about said cross sectional shape. Total rotation
angle was 60 degrees. Also at shoulder, cross sectional shape was a
regular hexagon, where each angle was rounded off with an arc. The
cross sectional shape was not rotated.
[0034] The bottles as designed above had good acceptability, and
had good "handleability" as well. After hot-pack filled and then
cooled, the bottles caused no problem in production-line
suitability. The bottles maintained acceptable appearance. When
subjected to a transportation test, the bottles caused neither
peeling of labels, nor buckling under loading.
INDUSTRIAL APPLICABILITY
[0035] The plastic bottles of this invention are usable as
containers for beverages on the market.
* * * * *