U.S. patent application number 15/974803 was filed with the patent office on 2018-09-13 for preform, a container, and a method for fabrication of a preform.
The applicant listed for this patent is NESTEC S.A.. Invention is credited to Jean-Paul Cerveny, Nicolas Dabrowski, Christian Detrois, Emmanuel Laine, Erik Lupke.
Application Number | 20180257362 15/974803 |
Document ID | / |
Family ID | 46750188 |
Filed Date | 2018-09-13 |
United States Patent
Application |
20180257362 |
Kind Code |
A1 |
Cerveny; Jean-Paul ; et
al. |
September 13, 2018 |
PREFORM, A CONTAINER, AND A METHOD FOR FABRICATION OF A PREFORM
Abstract
A method for fabricating a preform by providing a plurality of
preform segments which each define a portion of a preform,
positioning said preform segments in continuous contact with each
other along at least one edge of said preform segments such that
said plurality of preform segments define a cavity, and bonding
each of said preform segments to at least one other preform segment
such that said plurality of preform segments forms a continuous
whole.
Inventors: |
Cerveny; Jean-Paul; (Vittel,
FR) ; Dabrowski; Nicolas; (Vittel, FR) ;
Detrois; Christian; (Epalinges, CH) ; Laine;
Emmanuel; (Vittel, FR) ; Lupke; Erik; (KB Den
Haag, NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NESTEC S.A. |
Vevey |
|
CH |
|
|
Family ID: |
46750188 |
Appl. No.: |
15/974803 |
Filed: |
May 9, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14414756 |
Jan 14, 2015 |
9987831 |
|
|
PCT/EP2013/065729 |
Jul 25, 2013 |
|
|
|
15974803 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29K 2105/0094 20130101;
B29C 66/71 20130101; B29B 11/08 20130101; B29B 2911/14573 20130101;
B29C 66/73122 20130101; B65D 1/40 20130101; B29C 66/81463 20130101;
B29B 11/10 20130101; B29C 66/81422 20130101; B29C 66/81423
20130101; B29C 66/73921 20130101; B29B 2911/14326 20130101; B29C
66/1224 20130101; B32B 37/0046 20130101; B65D 1/0207 20130101; B32B
37/06 20130101; B29C 66/612 20130101; B29C 49/0078 20130101; B29B
11/14 20130101; B29C 49/12 20130101; B32B 37/18 20130101; B29C
65/08 20130101; B29C 66/5344 20130101; B29C 66/1222 20130101; B29C
2049/021 20130101; B29C 66/63 20130101; B65D 1/0223 20130101; B29C
66/83221 20130101; B29B 2911/14433 20130101; B29K 2067/003
20130101; B29B 2911/14373 20130101; B29C 65/48 20130101; B29K
2023/12 20130101; B32B 2439/00 20130101; B29C 66/3452 20130101;
B29B 2911/14013 20130101; Y10T 428/1397 20150115; B29B 2911/14353
20130101; B29K 2105/258 20130101; B29K 2995/0021 20130101; B32B
37/24 20130101; Y10T 156/10 20150115; B29B 2911/1448 20130101; B29C
66/131 20130101; B29C 66/543 20130101; B29B 2911/1434 20130101;
B29C 66/542 20130101; B29B 11/04 20130101; B29B 2911/14333
20130101; B29C 66/71 20130101; B29K 2067/003 20130101; B29C 66/71
20130101; B29K 2023/12 20130101 |
International
Class: |
B32B 37/24 20060101
B32B037/24; B65D 1/40 20060101 B65D001/40; B65D 1/02 20060101
B65D001/02; B29B 11/04 20060101 B29B011/04; B29B 11/14 20060101
B29B011/14; B29C 65/08 20060101 B29C065/08; B29C 65/00 20060101
B29C065/00; B32B 37/00 20060101 B32B037/00; B32B 37/06 20060101
B32B037/06; B32B 37/18 20060101 B32B037/18 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 3, 2012 |
EP |
12179128.9 |
Claims
1. A preform comprising a plurality of preform segments each
defining a portion of the preform, each of the preform segments is
bonded to at least one other preform segment to constitute the
preform with a cavity defined by the plurality of preform
segments.
2. The preform of claim 1, wherein the preform comprises an open
end communicating with the cavity, the open end being provided with
a member for interfacing with a closure device.
3. The preform of claim 1, wherein the preform segments comprise
walls of at least two different thicknesses.
4. The preform of claim 1, wherein the preform segments have at
least two different intrinsic viscosities.
5. The preform of claim 1, wherein the preform segments are
fabricated from at least two different materials.
6. The preform of claim 1, wherein the preform segments are of at
least two different colors.
7. The preform of claim 1, wherein the inside diameter of the
preform at a cross-section is greater than the inside diameter of
the preform at an open end of the preform.
8. The preform of claim 1, wherein the preform comprises an open
end offset from the longitudinal axis of the preform.
9. The preform of claim 1 comprising at least one rib located upon
a surface of the preform.
Description
PRIORITY CLAIM
[0001] This application is a divisional of U.S. application Ser.
No. 14/414,756 filed Jan. 14, 2015, which is a National Stage of
International Application No. PCT/EP13/065729 filed Jul. 25, 2013,
which claims priority to European Application No. 12179128.9 filed
Aug. 3, 2012, the entire contents of which are incorporated herein
by reference.
BACKGROUND
[0002] This invention relates to a method for the fabrication of
preforms notably for use in the fabrication of containers. In a
general way, it concerns the fabrication of containers, and for
instance beverage containers, from preforms. This invention further
relates to a preform so produced by this method and a container
which is fabricated therefrom.
[0003] A well-known and commonly-employed technique in the art of
fabricating containers is the method of blow-molding, wherein a
mass of material is expanded to match the contours of a mold
disposed about said mass. This is achieved by the injection of a
working fluid, usually air, into the mass, inflating it and causing
it to plastically deform.
[0004] One variant of this technique is the method of stretch blow
molding. In the method of stretch blow molding, the mass is
deformed in the longitudinal direction by a mechanical device known
as a stretch rod, and in the radial direction by inflation. This
technique is widely employed in the art of container fabrication,
as it may be employed to rapidly and economically produce large
quantities of containers with consistent dimensions and physical
properties.
[0005] In the blow molding method and stretch blow molding method,
the mass is referred to as a "preform." The preform is generally
fabricated from a thermoplastic polymer, such as polypropylene (PP)
or polyethylene terephthalate (PET); such plastics have the
advantage of being generally inexpensive, versatile, durable, and
easily-worked.
[0006] The preform has a form resembling a test tube, having a
tubular body, a closed end, and an open end into which the working
fluid is injected. The preform may be further provided at its open
end with threads, flanges, shoulders, or other such means to
facilitate the closure and/or sealing of the container fabricated
therefrom.
[0007] The remainder of the preform, however, is essentially a
featureless plastic tube, which deforms during the injection of the
working fluid. The open end of the preform is generally not
deformed during the container fabrication process, with the result
that the fabrication of the neck and mouth of the finished
container is substantially completed during the fabrication of the
preform.
[0008] The preform is fabricated by a method of injection molding,
wherein a molten plastic is injected at great pressure into a mold
of the preform. This preform mold is generally composed of three
segments: two which define the exterior surface of the preform and
one which defines the interior surface of the preform. The molten
plastic is injected through a port in the mold at or near where the
closed end of the preform is formed, from which it proceeds to fill
the mold cavity. Once the molding of the preform is complete, the
two exterior mold segments are withdrawn, the interior mold segment
extracted through the open end of the preform, and the preform is
removed.
[0009] The method of fabricating preforms known in the prior art is
disadvantageous in several aspects.
[0010] First, the prior art process for fabricating preforms is
disadvantageous in that it requires the preform to be of a minimum
thickness, generally about 2 millimeters. Injection molding
components which have dimensions thinner than this induces
undesirable stresses in the preform material and molding apparatus,
and requires a higher injection pressure and greater injection time
to complete the injection-molding process compared to components
which respect this minimum. This increased process time will render
the use of injection molding economically infeasible for mass
production of preforms in configurations which may be otherwise
ideal.
[0011] In addition, the molten plastic may solidify prematurely if
it is injected into a mold cavity feature thinner than this minimum
thickness, preventing the entire mold cavity from being filled.
[0012] This method of fabricating preforms is therefore
disadvantageous in that it does not permit the economical
mass-production of preforms with walls which are not at least 2
millimeters thick. Thus, in many cases preforms must be fabricated
with more material than is strictly necessary to form the beverage
container into which they will eventually be expanded, wasting
material and increasing costs.
[0013] Second, the prior art process is disadvantageous in that the
segment of the preform mold which defines the inside of the preform
reduces the number of possible shapes that the preform may have.
More specifically, the fact that a segment of the mold must be
extracted from the interior of the preform via its open end means
that the interior diameter of the preform at any point must never
exceed the interior diameter of the open end. If not, it will be
impossible to extract said mold segment from the preform. Thus,
preforms which have a cross-section with an interior diameter
greater than that of the open end may not be produced by the
injection molding process. This limits the possible geometries of
the preforms, constraining their utility and, by extension, the
flexibility and utility of the containers ultimately fabricated
from those preforms.
[0014] Third, the prior art process is disadvantageous in that the
nature of the injection molding step requires the plastic injected
to be homogeneous. In other words, each and every part of the
preform must be of the same material and have the same physical
properties as every other part. It is thus not possible to create,
for example, a preform which is more inclined to expansion in one
part than in another or one which has variations in its color or
texture across its surface. This is disadvantageous in that it
limits the applications in which the prior art process may be
practice and reduces its overall utility and flexibility.
SUMMARY
[0015] It is accordingly an objective of the invention to provide a
method for the fabrication of preforms which embody a greater range
of geometries and compositions, and which may be better conformed
to the applications in which they are eventually to be used.
[0016] According to a first aspect, the invention is directed to a
method for fabricating a preform, comprising the steps of providing
a plurality of preform segments, each of said preform segments
defining a portion of the preform; positioning said preform
segments in continuous contact with each other along at least one
edge of said preform segments, such that said plurality of preform
segments define a cavity; and bonding each of said preform segments
to at least one other preform segment such that said plurality of
preform segments forms a continuous whole.
[0017] This method is advantageous in that by it one may fabricate
preforms where each region of the preform is optimized according to
the shape of the container which will eventually be produced from
that preform. The preform is thus, as a whole, optimally configured
to the form of the container which will be fabricated from it,
reducing the amount of material required for the preform and
reducing the cost and weight of the containers produced from
them.
[0018] Furthermore, as the method permits the preform segments to
be fabricated individually, each segment of the preform may be
fabricated in the form and by the method which is optimal for that
particular segment, and without consideration of the form of
neighboring segments. This enables the fabrication of preforms
which would not be feasible if only one method of fabrication was
employed to fabricate a one-piece preform as in the prior art.
[0019] Additionally, the preform segments may be fabricated by a
wider variety of methods than by those available for the
fabrication of a one-piece preform. By this aspect of the
invention, the advantages of blow molding may be realized in the
fabrication of a greater variety of preforms.
[0020] Since the preform segments are fabricated individually and
bonded together, there is no need for a mold portion to define the
interior of the preform. The shape of the preform so fabricated may
be defined without regard to the limitations of the
injection-molding process. The preform made according to the method
of this invention, then, may be made in shapes which are more
complex and better adapted to the containers which will be formed
from them than the preforms known in the art.
[0021] According to a feature of the invention, the bonding step is
achieved by ultrasonic welding. Ultrasonic welding is especially
suited for the fabrication of preforms, as it is quick, sanitary,
and can create a hermetic seal of great strength.
[0022] In this way, the invention may be practiced with greater
speed and efficiency, while simultaneously augmenting the physical
characteristics of the preforms so fabricated.
[0023] According to another feature of the invention, the preform
segments are fabricated by injection molding or extrusion.
[0024] This is advantageous in that techniques for injection
molding and extrusion, especially of the varieties of plastics
known in the art of preform fabrication and container production,
may be adapted to produce uniform, high-quality preform segments at
high rates.
[0025] According to another feature, the inside diameter of the
preform at a cross-section is greater than the inside diameter of
the preform at its open end.
[0026] This is advantageous in that it permits the fabrication of
preforms which may be better adapted to be expanded into certain
shapes of containers, but which cannot be produced by the methods
known in the art, wherein an internal mold portion has to be
extracted through the open end of the preform.
[0027] According to a second aspect, the invention is directed to
an apparatus for the fabrication of a preform according to the
method described above.
[0028] This is advantageous in that it embodies the inventive
aspects of the method described above, realizing their advantages
in the fabrication of preforms for the production of
containers.
[0029] According to a third aspect, the invention is directed to a
preform, comprising a plurality of preform segments each defining a
portion of said preform, each of which is bonded to at least one
other preform segment so as to constitute said preform with a
cavity defined by said plurality of preform segments.
[0030] This is advantageous in that a preform fabricated from a
plurality of preform segments may be produced in a wider array of
shapes and sizes than the one-piece preforms known in the art. A
preform which cannot be efficiently, economically, or reliably
fabricated as a single piece may be easily fabricated as a
plurality of preform segments which are subsequently bonded
together.
[0031] Furthermore, the preform segments may be fabricated by
different techniques, each preform segment reflecting and taking
advantage of the particular technique used to fabricate it. This
permits the preform segments to be fabricated with optimal
efficiency, reducing the cost of the preform overall. The resulting
preform is thus highly adaptable to a wide variety of applications
at a minimum of cost.
[0032] According to a feature, said preform comprises an open end
communicating with the cavity, said open end being provided with
means for interfacing with a closure device.
[0033] This is advantageous in that it permits a closure device to
be attached to the container produced from the preform without any
additional preparation or structure, thereby expediting the closure
and sealing of the container after it has been filled. The cost of
using a container fabricated from a preform according to this
invention is thereby reduced.
[0034] According to another feature, the walls of the preform
segments are of at least two different thicknesses.
[0035] This is advantageous in that the preform may be configured
so that its thickness in any region is optimal for the degree of
expansion which that region will undergo when the preform is
expanded into a container.
[0036] Specifically, a thick segment may be used where a great deal
of expansion is expected, and a thinner one where less is to occur.
In this way, the amount of material in the preform, and by
extension the weight of the container produced therefrom, may be
minimized.
[0037] According to still another feature, the preform segments
have at least two different intrinsic viscosities.
[0038] This is advantageous in that it results in a preform which
is fabricated of preform segments of a single material, yet which
behave differently when the preform is expanded into a
container.
[0039] Intrinsic viscosity is a measurement of the propensity of a
plastic for deformation and is a function of polymer chain length,
thus two preform segments may be fabricated from the same material
yet have different intrinsic viscosities and, therefore, expand to
different degrees when the preform is expanded into a
container.
[0040] In this way, the behavior of a preform fabricated from a
plurality of preform segments may be more finely controlled during
expansion into a container, while still maintaining overall
uniformity of other physical characteristics.
[0041] According to still another feature, the preform segments are
fabricated from at least two different materials.
[0042] This is advantageous in that the physical properties of each
preform segment may be better adapted for the preform which
incorporates them.
[0043] For example, it may be desired that a container is durable
and resilient at its neck and base, while being soft and pliable
around its midsection where it is gripped. The preform segments
corresponding to these areas of the container may thus be
fabricated from different materials, so as to better meet these
requirements. The physical properties of the container produced
from such a preform may be varied to suit the application in which
it is used.
[0044] According to still another feature, the preform segments are
of at least two different colors.
[0045] This is advantageous in that containers produced from the
one-piece preforms known in the art must necessarily be all of one
color. By fabricating a preform from preform segments of more than
one color, containers may be produced therefrom which are more
visually diverse and aesthetically appealing.
[0046] According to still another feature, the inside diameter of
the preform at a cross-section is greater than the inside diameter
of the preform at an open end of said preform.
[0047] This is advantageous in that the preform is better adapted
to be expanded into containers of more and different shapes than is
practicable with the preform known in the prior art.
[0048] According to still another feature, the preform comprises an
open end offset from the longitudinal axis of the preform.
[0049] This is advantageous in that containers fabricated from such
preforms will therefore be provided with open ends which are offset
from their axes. This makes such containers easier to pour when
held in the hand, especially when fabricated in larger volumes. The
preform incorporating this feature may thus be better adapted to
the applications in which it is to be employed.
[0050] According to still another feature, the preform further
comprises at least one rib disposed upon a surface of said
preform.
[0051] This is advantageous in that the addition of ribs to the
preform will, after the expansion of said preform, result in a
container with corresponding ribs on its surface. Such ribs serve
to add strength to the container.
[0052] The thickness of the preform, and thus of the container, may
be reduced overall without sacrificing the resistance of the
container to external loads or the pressure of the contents
contained within.
[0053] Alternately, the thickness of the preform may be maintained
and the ribs added to give the resultant container greater strength
than would be achievable with a preform as known in the prior
art.
[0054] The preform of this invention thus renders the fabrication
of preforms and containers less expensive, while simultaneously
improving the suitability of said preforms and containers for the
applications in which they are to be employed.
[0055] According to a fourth aspect, the invention is directed to a
container fabricated from a preform according to the above
description.
[0056] This is advantageous in that such a container will embody
the other aspects and features of the invention. The advantages of
the invention are thus realized in containers which are stronger,
lighter, more economical, more versatile, and better suited to
their respective applications than those known in the art.
[0057] Other particularities and advantages of the invention will
also emerge from the following description.
[0058] In the accompanying drawings, given by way of non-limiting
examples:
BRIEF DESCRIPTION OF THE DRAWINGS
[0059] FIG. 1 depicts a section view of a preform according to a
first embodiment;
[0060] FIG. 2 depicts a section view of a preform according to a
second embodiment;
[0061] FIG. 3 depicts a side view of a container fabricated from a
preform according to the second embodiment;
[0062] FIG. 4 depicts a section view of a preform according to a
third embodiment;
[0063] FIG. 5 depicts a side view of a container fabricated from a
preform according to the third embodiment;
[0064] FIG. 6 depicts a side view of a preform according to a
fourth embodiment;
[0065] FIG. 7 depicts a removed section view of a preform according
to the fourth embodiment; and
[0066] FIGS. 8a through 8c depict an apparatus for the fabrication
of a preform according to the method of the invention.
DETAILED DESCRIPTION
[0067] FIG. 1 depicts a preform according to a first embodiment of
the invention. In a first step for fabrication of the preform 100
of FIG. 1 a plurality of preform segments 101-103 are provided,
each of which is substantially ring-shaped and defines a portion of
the preform 100. In this embodiment, the preform 100 comprises a
mouth segment 101, a body segment 102, and a tail segment 103.
Preferably, the preform segments 101-103 are symmetric about a
longitudinal axis 104 of the preform 100.
[0068] In a second step for fabrication of the preform 100, the
preform segments 101-103 are positioned so as to be in continuous
contact with each other along at least one edge of said preform
segments 101-103. In this embodiment, an edge of the mouth segment
101 is in continuous contact with an edge of the body segment 102
along a first seam 105. A second edge of the body segment 102 is in
continuous contact with an edge of the tail segment 103 at a second
seam 106. The arrangement of the preform segments 101-103 in this
manner thus defines a cavity 107 within the preform 100 which is in
communication with the open end 108.
[0069] Once positioned in contact with each other, the preform
segments 101-103 are bonded to each other along the first and
second seams 105 and 106, such that the preform segments 101-103
form a continuous preform 100.
[0070] This bonding step is preferably performed by ultrasonic
welding, which can rapidly produce a clean, high-strength bond in
food-grade plastics and is thus ideal for the fabrication of
preforms for beverage containers. It should be understood, however,
that other processes such as thermo-sealing or gluing may be
appropriate for other applications or preform materials.
[0071] Preferably, each of the preform segments 101-103 is
fabricated according to the method which is most efficient and
yields the best results for that particular preform segment. For
example, the mouth segment 101 is provided with threads 109 and a
rim 110 for interfacing with a closure device, such as a screw-on
cap 111, and is relatively thick overall; its fabrication may thus
be optimally performed by injection molding. Similarly, the body
segment 102 is essentially a featureless tube, and is much thinner
than either the mouth segment 101 or the tail segment 103; it may
be optimally fabricated by extrusion molding or similar processes.
In this way, one may configure the fabrication of the preform
segments 101-103 such that the properties of the resultant preform
100 are optimized.
[0072] FIG. 2 depicts a preform according to a second embodiment of
the invention. The preform 200 is comprised of five preform
segments: a mouth segment 201, an expansion segment 202, a body
segment 203, a contraction segment 204, and a tail segment 205. As
in the first embodiment depicted above, the preform segments
201-205 are positioned in continuous contact along their edges and
bonded to each other along several seams 206-209 to form the
preform 200. As in the first embodiment, the arrangement of the
preform segments 201-205 defines the cavity 210 within the preform
200.
[0073] While the preform 200 is bonded at each of the seams
206-209, it should be understood that alternate configurations of
the preform segments may require fewer bonds to fabricate a
preform. The exact configurations of the preform segments and the
seams at which they are bound to each other may be optimized for a
particular application.
[0074] The cylindrically-shaped body segment 203 is of a greater
diameter than the mouth segment 201 and tail segment 205, and as
such cannot be bonded to them directly. The expansion and
contraction segments 202 and 204 are thus in the shape of conical
frustums, permitting the body segment 203 to be connected to the
mouth and tail segments 201 and 205.
[0075] The method of fabricating a preform of the invention permits
one to fabricate a preform where the diameter at any section of the
preform is not constrained by the diameter of the preform at its
open end. In FIG. 2, the preform 200 has a diameter D.sub.1 at its
open end 211 which is smaller than the diameter D.sub.2 at the body
segment 203.
[0076] The preform segments may be configured so as to be of
different thicknesses. Preform segments which will undergo a high
degree of expansion (especially radial expansion) when the preform
is fabricated into a container may be made with thick walls.
Preform segments corresponding to areas of the finished container
where high degrees of strength will be required may also be made
with thick walls. Conversely, preform segments corresponding to
areas of low expansion may be made with thin walls. In this way,
the amount of material used to fabricate the preform may be
minimized.
[0077] FIG. 2 shows that the mouth segment 201 and the tail segment
205 are fabricated so as to be thicker than the expansion, body,
and contraction segments 202-204. When the preform 200 is expanded
into a container, the tail segment 204 will undergo a great deal of
radial expansion, necessitating its increased thickness. The mouth
segment 201 will not undergo expansion, but as it comprises the
threads 212 and rim 213 to which a closure device will be affixed,
it is advantageously made with additional thickness to give it
improved strength. This is especially advantageous in containers
for carbonated beverages and other substances under pressure.
[0078] FIG. 3 depicts a container fabricated from the preform of
FIG. 2. The container 300 is of a large diameter. The use of
expansion and contraction segments 202 and 204 in the preform, as
depicted in FIG. 3, permit the fabrication of a container 300 with
a larger diameter than might otherwise be feasible with the methods
known in the prior art.
[0079] FIG. 4 depicts a preform according to a third embodiment of
the invention. The preform 400 is fabricated from eight preform
segments 401-408, which are disposed in contact with each other as
shown and bonded along their edges at several seams 409-415. The
resultant preform 400 is thus provided with a cavity 416 in
communication with an open end 417. The preform 400 is in a shape
substantially resembling an hourglass, which when expanded will
yield a substantially hourglass-shaped container.
[0080] The preform segments 401-408 are further provided with ribs
418 upon their internal surfaces. These ribs 418 serve to add
additional structural strength and resistance to the container
fabricated from the preform 400.
[0081] While FIG. 4 depicts an example of a preform in an hourglass
shape, the method of the invention permits many other shapes,
textures and contours to be realized in preforms, and by extension
in containers. The invention thus offers a greatly increased
variety of possible container shapes and sizes.
[0082] Furthermore, the fabrication of preforms from multiple
preform segments permits the material properties of each preform
segment to be chosen individually. In FIG. 4, two body segments 403
and 407 are fabricated from a differently-colored plastic than the
rest of the segments of the preform 400. In a variation, the
preforms may include preform segments fabricated from different
materials. In another variation, the preform segments may be
fabricated from plastics comprised of the same type of polymer but
with different intrinsic viscosities. This results in preforms
which are more disposed to deformation in certain regions than in
others, but whose physical properties are otherwise uniform. In
this way, the present invention greatly increases the flexibility
and adaptability of the preforms used in the blow-molding process
and, by extension, the variety of containers which may be so
produced.
[0083] FIG. 5 depicts a container fabricated from the preform of
FIG. 4. The container 500 is generally hourglass-shaped,
corresponding to the shape of the preform 400 of FIG. 4. The
container 500 is further provided with two contrasting-color bands
501 and 502, corresponding to the body segments 403 and 407
depicted in FIG. 4.
[0084] FIG. 6 depicts a preform according to a fourth embodiment of
the invention.
[0085] The preform 600 is fabricated from three preform segments: a
substantially ring-shaped neck segment 601, and two body segments
602 and 603. The body segments 602 and 603 are substantially
identical, and are bonded along a longitudinal seam 604 to create a
preform body 605 which is substantially tubular and closed at a
first end 606. The neck segment 601 is bonded to the preform body
605 at a second end 607, along a circumferential seam 608, thereby
producing the preform 600 which defines a cavity 609.
[0086] The neck segment 600 is provided with a mouth 610 with a
centerline 611. The preform mouth centerline 611 is offset from the
preform body centerline 612, which is shown in greater detail in
Section A-A of FIG. 7.
[0087] FIG. 7 is a section view of the cavity 609 of the preform
600, looking towards the inside surface of the neck segment 601.
The mouth 610 has a mouth center 613 which corresponds to the
preform mouth centerline 611 of FIG. 6. The preform body 605 has a
body center 614, likewise corresponding to the preform body
centerline 612 of FIG. 6. The mouth and body centers 613 and 614
are offset from each other with the offset distance
D.sub.offset.
[0088] When the preform 600 according to this embodiment is
fabricated into a container, the resulting container will have a
neck which is offset from the overall centerline of the container.
Such a container will be easier to pour, especially in large
capacities.
[0089] FIGS. 8a through 8c depicts an apparatus for fabricating a
preform according to the method described above. More specifically,
FIGS. 8a through 8c depict the disposition of the apparatus before,
during, and after a step for bonding of two preform segments by
ultrasonic welding.
[0090] FIG. 8a depicts the apparatus before a step for bonding two
preform segments. An upper segment 800 and lower segment 801 are
provided. The upper segment 800 is provided with a mating flange
802, while the lower segment 801 is provided with a shoulder 803
and counterbore 804 configured to accept the mating flange 802 of
the upper segment 800.
[0091] Furthermore, disposed on the lateral surface of the
counterbore 804 of the lower segment 801 is a force concentrator
805. The force concentrator 805 is ideally configured as a
circumferential ridge of triangular cross-section, though it may
instead be advantageous to provide a force concentrator in other
sizes, dispositions, or cross-sections than depicted here.
[0092] Preferably, when the mating flange 802 of the upper segment
800 is inserted into the counterbore 804 of the lower segment 801,
the force concentrator 805 will create a mild interference fit with
the mating flange 802. This will serve to hold the two segments 800
& 801 together prior to the bonding step, facilitating their
handling and bonding in a production environment.
[0093] The apparatus is provided with an ultrasonic anvil 806 and
two ultrasonic horns 807. The ultrasonic anvil 806 is substantially
rod-shaped, while the ultrasonic horns 807 are configured as plates
with semicircular cutouts 808. The semicircular cutouts 808 are
preferably configured to substantially match the lower segment 801
at the shoulder 803, though it should be understood that providing
ultrasonic anvil and horns in other configurations may be
preferable for other embodiments.
[0094] FIG. 8b depicts the apparatus during the bonding step. The
upper segment 800 is inserted into the lower segment 801, such that
the mating flange 802 is disposed within the counterbore 804. The
ultrasonic anvil 806 has been advanced into the upper segment 800
and the ultrasonic horns 807 have been advanced laterally into the
lower segment 801, thereby pressing the two segments 800 & 801
together at the interface 809 between the two. The ultrasonic horns
807 are made to vibrate at ultrasonic frequencies, thereby
generating heat from friction which causes the upper and lower
segments to melt together and be bonded.
[0095] FIG. 8c depicts the apparatus after the bonding step has
been completed. The preform segments 800 & 801 have been bonded
together, yielding a continuous single piece 810. The ultrasonic
anvil 806 and horns 807 are retracted, and the process may be
repeated for another pair of preform segments.
[0096] Of course, the invention is not limited to the embodiments
described above and in the accompanying embodiments. Modifications
remain possible, particularly as to the construction of the various
elements or the substitution of technical equivalents, without
departing from the scope of protection of the invention.
[0097] In particular, it should be noted that the configuration and
arrangement of the preform segments is not limited to the examples
given and minor variations thereof. Preform segments in
configurations other than the ring-shaped and longitudinally-split
variations described above remain possible, and will permit the
fabrication of many different types of preforms not described in
this document but nonetheless within the scope of the
invention.
[0098] The exact configuration of the invention as practiced may
thus vary from the foregoing description without departing from the
inventive principle disclosed therein. Accordingly, the scope of
this disclosure is intended to be exemplary rather than limiting,
and the scope of the invention is defined by any claims that stem
at least in part from it.
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