CA2100758C

CA2100758C - Multilayer bottle with separable inner layer

Info

Publication number: CA2100758C
Application number: CA002100758A
Authority: CA
Inventors: Steven L. Schmidt; Wayne N. Collette; Suppayan M. Krishnakumar
Original assignee: Continental PET Technologies Inc
Current assignee: Graham Packaging Pet Technologies Inc
Priority date: 1991-01-23
Filing date: 1992-01-10
Publication date: 1998-07-28
Anticipated expiration: 2012-01-10
Also published as: AU1241792A; US5301838A; NZ241354A; US5332121A; US5407629A; MX9200276A; DE69201437T2; DE69201437D1; EP0567574A1; WO1992012926A1; JPH06505463A; JP3328276B2; FI933308A; AU669655B2; CA2100758A1; FI933308A0; EP0567574B1; ATE118428T1

Abstract

A multilayer plastic container (50) for use with either a positive or negative pressure dispensing system (10), the container having an integral body with an inner layer (58) which readily separates from an outer layer (59) and collapses to dispense a product from the container. The container is formed by blow-molding a multilayer preform, and a bottom aperture (57) is formed in the container for injecting air to separate the inner layer from the outer layer. Preferably, the inner layer is predelaminated during manufacture to facilitate its later separation during use. In the case of vacuum dispensing, air inlet vent holes are preferably formed at the points of maximum deformation to prevent collapse of the outer layer.

Description

~ '/1'926 2 ~ O O I ~ 8 Pcr/~ss2/ooog~

MULTILAYER BOTTLE WITH SEP~RABLE INN2R
LAYER

This is a continuation-in-part of copending U,S, Serial Nos, 07/644,624 filed l/23/9l by Schmidt et al,, and 07/698,931 filed 5/13/9l by Schmidt, This invention relates in general to new and useful impro~ements in dispensing containers, ..
and more specifically ~o a multi-layer plastic container having an inner layer which is readily separable from an outer layer for independent collapse under positive or negative pressure to dispense a product packaged wi~hin the container.
. ':
Backqround of the Inv~ntion The known liquid dispensing systems for beverages and concentrated beverage syrup~ include a pressurized stainless s~eel dispenser and a more ; : :recently developed "bag in a box." The stai~less . .
: ~ steel d:ispenser has the ad~antage of being reusable, ;~
~: howev~r, it is v~ry expensive to manufacture and ', :: somewhat heavy and dif~icult ~o handle. The "bag in ;'.
:a box," consisting of a separately formed plastic :: ~ liner in a corrug~ed paper box, is lighter in weight and less expensive to manu~acture, but it is :i:
not reusable or recyclabie and is susceptible to leakage if dropped. Although it has been suggested ., 'j to provide a plastic container with a separately :~ :

~ :, SUEt~3T3TUTI~ SHEET i~

CA 021007~8 1998-01-29 formed liner which is inserted in the container, this container has proven to be both too difficult and expensive to manufacture and as such is not commercially feasible. Thus, there exists the need for a dispensing system which will overcome the aforementioned problems.
Summary of the Invention In accordance with this invention, a multi-layer container for a dispensing system is provided having an inner layer which readily separates from an outer layer when positive or negative pressure is applied, in order to dispense a product from the container. The "inner layer" and "outer layer" may each be a single layer, or a plurality of layers. The container is economical to manufacture, light in weight, easy to handle, can be made of recyclable materials, and is "product efficient" in that substantially all of the product can be dispensed from the container during use.
In another aspect of the present invention, there is a dispensing container having a substantially rigid outer body and a flexible collapsible inner bag with the inner bag holding a product to be dispensed, the container having an open end from which the product is dispensed and a closed end, the improvement comprising the inner bag and outer body being inner and outer layers respectively of a unitary multilayer expanded plastic preform container, wherein the inner layer is continuous and separate from the outer layer at the closed end of the container and joined thereto at least at the open end, and an opening is provided in the outer layer at the closed end to enable air to enter between the inner and outer layers to facilitate collapse of the inner layer.
In a further embodiment of the present invention, there is a squeezable container for dispensing a product comprising:

CA 021007~8 1998-01-29 - 2a -a dispensing container having a resilient outer body and a flexible collapsible inner bag with the inner bag holding a product to be dispensed, the container having an open end from which the product is dispensed and a closed end, the inner bag and outer body being inner and outer layers respectively of a unitary multilayer expanded plastic preform container, wherein the inner layer is continuous and separate from the outer layer at the closed end of the container and joined thereto at least at the open end, and an aperture is provided in the outer layer at the closed end to enable air to enter between the inner and outer layers to facilitate collapse of the inner layer and form a chamber between the inner and outer layers; and a valve positioned in the aperture for restricting a flow of air into and out of the chamber.
A still further aspect of the present invention comprises a dispensing container having a resilient outer body and a flexible collapsible inner bag with the inner bag holding a product to be dispensed, the container having an open end from which the product is dispensed and a closed end, wherein the inner layer is separate from the outer layer at the closed end of the container and joined thereto at least at the open end, and an aperture is provided in the outer layer at the closed end to enable air to enter between the inner and outer layers to facilitate collapse of the inner layer, and wherein the inner layer has a tapered wall thickness, decreasing in thickness towards a base end of the container opposite the open dispensing end.
The multi-layer container is blow molded from a multi-layer polymeric preform having at least two layers, wherein the inner layer is made of a material having substantially no tendency to form primary chemical bonds with the outer layer. The CA 021007~8 1998-01-29 - 2b -polymer of the inner layer is thus not substantially melt soluble in the polymer of the outer layer. The ~2/1292~ 7 ~ ~ P~ S92/0~0~4 . .

only bonding which exists between the non-soluble polymer layers is secondary hydro~en (i.e~, ;
non-chemical) bonding. As such, the disimilar layers may be separated through the application of force.
For pressure disp0nsing applications, a positive pressure of 20 psi is sufficient to initiate and propogate delamination of the inner ,.
layer as required to dispense a product.
In a va~uum dispen~ing application, the negative pressure levels generated are gen~rally ;~ -insufficient to delaminate the internal layers. As such, it is necessary to predelaminate the inner layer via pressure, followed by xeinflation and : .
product filling prior to vacuum dispensing.
In a prefexred three-layer container, a thin boundary layer of a non-melt soluble second polymer is provided between innermost and outermost ~- layers of a fixst polymer. Either the innermost layer alone, or the innermost and boundary layers together, may collapse ~o dispense the product. In a preferred five-layer construction, a pair of boundary layers are provided between innermost, core and outermost layers. Preferably, only the innermost 7~ layer, or the innermost and adjacent i~ner boundary layers collapse to dispense the product, although it may be desirable in certain applications to collapse SU ~ STIT U T E S H EET

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W092/12926 P~r/us9~/oo~~ ' both the innermost, boundary and core layers~
Various o~her combinations of layers are also contemplated.
In a first embodiment, an aperture is provlded in the bottom of the container extending through the outer layer and ter~inating at least at the inner layer, so that a continuous inner layer is preserved. Thus, positive pressure may be applied externally through the bottom aperture against the inner layer for delaminating and collapsing the same. The bottom aperture may be formed in the preform or in the container.
In a second preferred embodiment, a "predelamination step" is proYided during manufacture of the container wherein the inner layer is ~ separated from and collapsed toward the open end of : the container, and the inner layer is then reexpanded to its original position adjacent the outer layer. This facilitates later collapse of the inner layer via vacuum after the container has been filled with a product and is ready ~or use.
' In yet another e~bodiment, vent holes are formed in the outer layer during the predelamination step, to form a container particularly adapted for ~5 vacuum dispensing. Thus, when a negative pressure is applied to the mouth of the container IO dispense ; a-product, the vent holes, located in the outer .
:

SUBSTITUTE SHEE~T

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~ ~, layer at the points of maximum deformation, preven'c collapse o~ the outer layer along with the irmer layer. .
The-container of thls invention, consisting :' of a relatively rigid outer layer and a separable liner, is useful for dispensing liquid products, such as a beverage or concentrated beverage syrup, as well as liquid/solid mixtures or slurries. For use with relatively thick (viscous) ma~erials, e.g., ketchup, ice cream, etc., a positive pressure dispensing apparatus is particularly preferred wherein positive pressure is applied through a bottom opening in the ou~er layer to delamina~e and collapse the i~ner layer and dispense ~he product.
For less viscous liguids, e.g., syrup concentrate or carbonated soft drinks, a ~ontainer with vent holes is preferred for use in a high-flow-rate vacuum dispensi~g system. I'High-flow" is defined as a product removal rate which exceeds the rate a~ which ambient air enters the region of the container be~ween the external and collapsing in~ernal layers -via the bottom ope~ing. Thus, whereas a high-flow-rate vacu~ applied at the mouth of the container may tend t:o cause the outer layer to collapse along with the i.nner layer, resul~ing in container distortion and standing instability, th~ vent holes prevent such collapse of the outer layer. The air ~iU13~ 1TUTE SH EIE~T

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-CA 021007~8 1998-01-29 inlet vent holes are located at the point(s) of maximum deformation and their number depends on the number of such equal potential points.
A method of forming a container, in accordance with the present invention, comprises the steps of:
providing an integral plastic multilayer preform having an open end, a closed end, inner and outer adjacent layers, and an aperture formed in the closed end from the exterior of the preform and terminating at the inner layer;
expanding the preform to form a container having an integral body with a closed end, an open end, and a plurality of adjacent layers, wherein the preform layers following expansion form a continuous inner layer readily separable from an outer layer at the closed end of the body and joined thereto at least at the open end;
collapsing the inner layer to separate the inner layer from the outer layer at the closed end of the body; and returning the inner layer to a position adjacent the outer layer.
In a preferred method of manufacture, the container is prepared according to the following steps:
(1) injection mold a multilayer preform with an innermost layer of a first thermoplastic resin (e.g., polyethylene terephthalate) and a next innermost layer of a boundary 30material which is substantially non-melt soluble in the first resin (e.g., ethylene vinyl alcohol);

(2) form a hole in the bottom of the preform to a depth not to break through the innermost layer;

(3) reheat the preform and stretch blow mold a container.

CA 021007~8 1998-01-29 - 6a -If the preferred vacuum dispensing container is desired, additional steps (4)-(6) are provided:

(4) predelaminate at least the innermost layer by applying mechanical or fluid pressure through the bottom hole, whereby the next innermost boundary layer may or may not collapse with the innermost layer;

. ~92/129 6 2 1 0 0 7 ~ ~ PC~/US~2/~oosi~

(5) form air inlet vent: holes in the body of the container through the non~collapsed .:
outer layer(s); and (6) reinflate the collapsed inner layer(s) and inspect for leaks.
It is further preferred to form the bottom hole in the preform during injection molding of the preform, by an injection nozzle gate pin.
Alternatively, the bottom hole may be formed (~fter inj~ction molding) by drilling or milling, As a still further alternative, the hole may be ~ormed in the bottom of the blown container, as opposed to the preform.
These and other features of the i~ven~ion will be more particularly described by the following detailed description and drawings of certain preferred embodimen~s.

Brief Description of the Drawings Fig. l is a schematic elevational view of a 20 : container of this invention being used in a pressure :~ dispensi~g system, wherein an inner layer of the container is collapsed by posi~ive pressure applied through a bottom aperture to sg~1ee~e the liquid out the mouth of the container through a di~pensing hose.
~ ~ 75 Fig. 2 is a schematic elevational view of ;~ ~ an alternative embodimenit of the container oi~ this : .
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WO92tl2926 PCT/US92/O~g ~ 1 0 !D ~ 5 8 invention being used in a negakive pressure (i.e., vacuum3 dispensing system, wherein the inner layer is collapsed by the application of negative pressure at the mouth of the container and vent holes are provided in the outer layer to prevent collapse thereof.
Fig. 3 is a side elevational view of a multilayer preform from which the container of this invention is formed, and Fig. 3A is a sectional view lQ across the preform wall taken along section lines 3~-3~.
Fig. 4 is a schematic sectional view showing how the preform is formed in an injection mold.and wherein th~ gate pin is provided with an .
a extension for forming a bottom aperture through the outer layer of the preform.
Fig. 5 is an enlarged fragmentary view taken along the section llnes 5-5 of Fig, 4 showing more~specifically the function of the extension of the gate pin to form the ~ottom aperture.
~ Fig. 6 is a fragmentary sectional ~iew : ' showing an alternative method of forming the bottom aperture, wherein the aperture is formed through the outer layer of the preform utilizing a drill or mill.
a Fig. 7 is a vertical sectional view showing : how ~he preform is expanded in a blow mold to form a container according to this invention.

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-Fig. 8 is a fragmentary ver~ical sec~ional view of the bottom of the blown container showing how the inner layer is separated from the outer layer in a predelamination step.
Fig. 9 is a vertical sectional view showing how the inner layer is collapsed toward the mou~h of : .
the bottle during the predelamination step.
Fig. lo is a vertical sectional view showing an additional step for forming the preferred vacuum dispensing container, wherein air inlet vent holes are formed in the outer layer while the inner layer is collapsed. :
Fig. 11 is a vertical sectional view of the container of ~ig. 10 showing how the inn~r layer is reexpanded by the application of positive pressure at the mouth of the bottle to return the inner layer : to its original position adjacent the outer layer. :~ .
Fig. 12 is a fray~entary sectional view showing the bottom of a filled container held in a ~.
stabilixing base, : :
Flg. 13 is a fragmentary sectional view ~aken through the con~ainer wall of an alternative embodiment having five layers, wherein the two ~: : boundary layers are substantially as thick as the innermost, core and ou~ermos~ layers.
Fig. 14 is a fragme~ ary sectional vi~w taken through the container wall of another ~; : .. ' :, ' 5 ~ ~T

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WO92/12926 Pcr/us9~/ooog alternative embodimen~ havillg a seven-layer construction, wherein three relatively thin boundary layers are provided and both the innermost and first core layers are separated frorn the outer layers, Fig. 15 is a schematic side elevational view showing the number and location of air inlet vent holes for a container having a circular cross section.
Fig. lS is a schematic cross-sectional view taken along the section lines 16~16 of Fig, 15, showing three equally spaced vent holes.
Fig. 17 is a schematic side eleva~ional view showing the number and location of air inlet vent holes for a container having a circular lS cross-section with vertical panel ribs.
Fig. 18 is a schematic cross-sectional view ~aken along the section lines 18-18 of Fig. 17, showing three equally spaced vent holes.
Fig. 19 is a schematic side elevational view showing the number and location o~ air inlet ~ent holes for a container having a square cross . section.
~ FiCJ. 20 is a schematic cross-sectional view :: taken along the section lines 20-~0 of Fig. 19, ~5 showing four equally spaced vent holes.
Fig. 21 is a schematic side elevational view showing the number and location of air inlet S~iT~Tl~ s~

~92/12926 ~ ~a~P~ PC~/U~92/0009 vent holes for a container having a rectangular cross section.
Fig. 22 is a schematic cross-sectional view taken along the section lines 22-22 of Fig. 21, showing four spaced vent holes.

Detailed Description Referring now to the drawings, Fig. 1 illustrates a positive-pressure liguid dispenslrlg system 10 which utilizes a container 50 of this invention. The system includes a base 14 on which the container 50 is seated in sealed relation. The base 14 carries a standard 18 which is provided at the upper end thereof with an adjustable clamp member 17. The clamp member 17 engages a shoulder portion 56 of the container around and below a neck portion or thread finish 51, which includes external screw threads 53 and a neck flange 54. The thread f inish 51 carries a cap 16 whlch is pro~ided with a dispensing hose 11. The dispensing hose 11 ~erminates in a valved dispenser 12 which, when actuated, permits the product from within the container 50 to f1O~J out through a no~zle 13 thereof. In typical usage, the product within the container 50 will be a liquid and the li~uid will be ~5 dispensed into a glass ox other container (not shownj.

, SUB5iTlTlJTE SHEET

WO9~/129~6 PC~/US92/~00' 75~

The base 14 carries an air line 15 through which air or other gas under pressure is directed into a bottom opening 57 in a base portion 52 o~ the container. The positive pressure air pushes a separable inner layer 58 of the container upwardly towards the mouth 60 of the container to dispense the product, while a substantially rigid outer layer 59 of the container remains substantially unde~ormed.
The outer layer 59 remains relatively rigid due to ::
the internal pressure for dispensing the product, but would be applied relatively flexible without such pressure.
Fig. 2 shows an ~lterna~ive dispensing : syst~m 510 of this invention, wherein the product is dispensed under negative pressure (i.e., vacuumj.
In this system, a container 550 is provided which is ~ substantially similar to the container 50 of the :~ first embodiment, but which is "predelaminated" and .
inclu~es a plurali~y of air inlet vent holes 558 in :.
the rigid outer layer 557 at the points of maxim~n ~ -deformation, so that a vacuum applied to the mouth 560 of the container to dlspense the product collapses the inner layer 556, but not the outer layer 557. As shown in Fis. 2, atmospheric air ..
enters the vent holes 55~ to fill the space between the inner layer 556 and the outer layer 557, ~o prevent collapse of the outer layer 557. A cap ~16 . ~ .

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92tl2926 PCT/~2/0~0 is provided at the mouth 560 of the container, connected to a dispensirlg hose 511, to which a vacuum pump 509 is attached for drawing a vacuum dt the mouth of the container.
Fig. 3 illustrates a multilayer pre~orm 20 for ~orming a container in accordance with this invention. The preform 20 includes an elongated cylindrical body 22 having a generally hemi~pherical closed bottom end 24 and an open top end 25 with a thread finish 26 and neck flange 23. Th~ preform 20 has multiple layers, which as ~hown in Figs. 3-4, include an innermost layer 36, an inner boundary lay~r 37, a core layer 38, an outer boundary layer 39, and an outermost layer 40, in serial relation :-1~ from the inner to the outer surfaces of ~he preform. In this preferred five-layer structure, the in~ermost and outermost layers 36 and 40 are of substantially equal thickness and are formed of the same thermoplastic material, preferably polyethylene terephthalate (PET). The central core layer 38 is substantially twice the thickness o~ the innermost and outermost layers and is also formed o~ ~ET. The inner and outer boundary layers 37 and 39 are substantially thinner and are made of a different material having little if any primary af~inity for (i.e., tendeilcy to chemically bond or adhere to) the :: adjacent layers 36, 38 and 40. A preferred boundary :: ~

~ 5UB ~TIT U T E S H E~T

W~9~ 26 PCT/US92/0009 ~lno~

material is ethylene vinyl alcohol (EVOH), Other suitable materials include poly~hylene, polypropylene, nylon (MXD-6), etc.
The preform may be injected molded sub~tantially as described in U.S. Patent ~,609,516 entitled Method of Forming Laminated Preforms, issued September 2, 1986 on an application by Krishnakumar et al., which is hereby incorporated by reference in its entirety. The innermost layer 36 :
and outermost layer 40 are injected into an :~
injection mold 61 (see Fig. 4) at the same time and are normally formed of the same material and have the same thicknes~. The molten polymer is injected : through a nozzle 64 into a space between an outer li mold member 62 and core 63. ~ separate material for forming the boundary layers 37 and 39 is next inje~ted into the mold. Finally, the core layer 38 .::
:~ is inj~cted into the mold, and preferably is of the same~material as the layers 36 and 40, so as to ~0 complete the construction of ~he preform 20. Other core materials such as post~consumer (recycled) PET
: : may be utili~ed as well. . ~.
~ ~ In a preferred embodiment, an aperture 21 : is formed in the bottom of the preform during the ,~ injection molding process. As shown in Figs. 4 and S, this is preferably accompl~shed by providing t~le ~: gate pin h5 o~ the injection nozzle 64 with An ; ~

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. ,g~tl2926 2 -I O 0 7 5 ~ PCT/US92/00094 extension 66, wherein the aperture 21 may be automatically formed. At the time the ~ate pin 65 is moved to ~he nozzle closing positlon, the last injected plastic material which forms the core layer 38 is still molten with t~e result that the gate pin extension 66 will enter into the molten plastic :;
material of the outer layers 40, 39, 38 and 37, terminating at least at the innermost layer 36, to ~orm the opening 21.
In an alternative embodirnent shown ln Fig.
6, th~ aperture 21 in the bot~om ou~er layers of ~he pre~orm 20 is formed after the injection molding process, by externally machining an opening through : the outer layers 40, 39, 38 and 37 with a ~1at end :drill or mill 68. :
The preform 20 is now ready for blow - molding as shown in Fig. 7. The blow mold includes a lower mold body 70 whose inner surfaces define the expanded body of the container, while a retaining member 73 engages the thread finish 26 of the preform above the neck flange 23. A pressuri~ed fluid such as air (shown by arrow 72) enters the open mou~th 25 of ~he preform to expand ~he same and form the container 50.
The container body 50 is a unitary structure having ~ plurality o~ layers with a closed bottom end 52 and an open top end or mouth 60 (see $ ~ ~ ~TIT ~ T ~ ~~ :

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WO9~/12~26 PCT/Ui~9~/00~
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Figs. l, 7 and 8). The expanded body includes a graduated ~houlder portion 56, a cylindrical panel portion 55, and a hemispherical base 52, all o~
which have been 0xpanded within the blow mold 70 s from portions of the preform 20. The neck or thread finish 51 (which is in fact the thread finish 26 of the preform 20) includes exterior threads 53 and a neck flange 54. Other embodiments may include the freestanding containers of the champagne or footed Petalite type as shown in U.S, Design Patent 315,869, and U.S. Patent Nos. 3,598,27Q, 4t785,949 :~
and 5,066,528.
: There is substantially no primary (chemical~ bonding between the expanded layers of the container, i.e., between the inn~rmost layer 36 : of PET and the inner boundary layer 37 of EVOH. At .i' most:, secondary (hydrogen bonding) exists between these layers. As a result, when fluid under pressure is directed through a plug 71 into bottom ~ 20 opening 57, as shown in Fig. ~, the fluid will cause ;.
:: separation o~ innermost layer 36 from inner boundary ~;
layer 37 and collapse of the innermost layer 36 within the container. As shown in Fig. 9, innermost layer 36 collapsies upwardly towards the open mouth ;~ 60 of the container, until reaching the : substantLally thick and rigid thread ~inish portion ~: 51 or upper shoulder where there has been no g ~IT ~ T ~ 5 ~.

~2/I2926 ~ PCl/~S~2/0~0 substantial stretching of the plastic materials of the pre orm 20, and wherein the five layers 36-40 remain connected together. Thus, a substantially full collapsing of the innermost layer 36 is possible while the extreme upper part o~ the innermost layer 36 remains tightly joined to the outer layers 35. ;
For pressure dispensing, the initial delamination and collapse of the inner layer may occur while the product is in use. However, for either pressure or vacuum dispensing where the pressure may not be sufficient to delamina~e the layers, a predelamination step is performed. Thus, in the same manner as shown in Fig. 8, positive pressure is injec~ed ~hrough the bottom,aperture 57 : to delaminate and collapse innermost layer 36. For a pressure dispensing system, the innermost layer 36 may then be simply returned to its starting position by applying pressure through the open mouth of the container (see Fig. 11); alternatively a vacu~ may be drawn through the bottom aperture 57. However, if the container is to ~e used in a vacuum dispensing sys~em with a high rat0 of flow which may cause deformation of the outer layer, a plurality of '~ vent apertures 41 are ~ormed during predelamination in the panel section of th~ outer layers 35, where maximum deformation would occur. The vent holes ~1 ;

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1~ --are formed by a drill or flat end mill 80, or by touching with a hot point to melt the outer layers, while the innermost layer 36 remains collapsed jus~
below the neck of the container. Then, as shown in s Fig. 11, the innermost layer 36 is reinflated by . .
injecting positive pressure air through the mouth 60 of the container, and the container is automatically .
pressure tested for leaks.
As shown in Fig. 12, the container 50 is then filled with a liquid product 8 and is ready for dispensing. If desired, for example with a :
hemispherical base portion 52, the container may further include a separate base cup 82i in~o which the base 52 of th~ body is inserted for stabili3ing the container. For use in a pressure dispensing system, a pressurized air line would be ccnnected to the bottom aperture 57 (see air line 15 in Fig. 1).
In a vacuum dispensing system, aperture 57 may remain open.
The container may ~e made from a variety of materials, limited only by the requirement that the - :.
inner layer (which may include more than one layer) ~ be readily separable from the next inner layer.
Thus, the innermost, core and outermost layers 36, .:
33 and 40 may be made of any first thermoplastic resin, such as the polymers t~pically used in the ~ packaging industry, i.e., polyethylene teraphthalate : ' :
SUlE3~TOTlJTE SHEET
:

3 92/12926 210 Q 7 ~ ~ P~r/Us92/ooo94 (PET), polypropylene, polyethylene, pol~vinyl chloride, polycarbonate and mixtures thereof. The boundary layers 37 and 39 are made of a material which is not substantially melt soluble in and thus has substantially no tendency to chemically bond o adhere to the material of the other layers 36, 38 a~d 40. The boundary layers may be made o~ any second polymer resin such as ethylene vinyl alcohol (EVO~.), polyethylene vinyl alcohol (PVOH), nylon (e.g., MXD-6 sold by Mitsubishi Corporation, New.
Yor~, NY), and mixtures thereof. A particularly pre~exred container has innermost, core and out~rmost layers of PET and thin boundary layers of EVOH.
It is further contempla~ed that more than one layer may be collapsed as the separable liner.
: Thus,~in the five-layer structure previously described, the inner boundary layer 37 may collapse . .
along with the innermost layer 3~. Still further, the core layer 38, inner boundary layer 37 and inne~most layer 36 may collapse as a unit. Still : : further, outer boundary layer 39, core layer 38, ~ in~er~boundary layer 37 and innermost layer 36 may :~ collapse as a unit. A11 that is reauired is that '5 the remaining outer laver or layers be su~-icientlv rigid, and _n~ c~llaps;ble layers su~ficientiy pliable, to permit ready separa.ion between the .
:

SWg~ , :~ -, WO9~/129~6 Pcr/us~/o~os 2:1.U07~j8 ......
' ' inner and outer layers iand noncollapse of th0 outer layers, As a still fur~her embodiment, Fig. 13 shows a five-layer construction wherein all of the layers are of substantially e~ual thickness. The structure includes innermost layer 90, inner boundary layer 89, core layer 88, outer boundary layer 87, and outermost layer 86. In the illustrated case, innermost layer 90 separates from inner boundary layer 89 to form the collapsi~le liner.
In a further embodiment shown in ~ig. 14, a seven-layer structure is provided wherein innermost layer 98, inner boundary layer 97 a~d fir~t core layer 96 separate as ~ unit to form the collapsible :liner, and the central boundary layer 95, second core layer 94, outer boundary layer 93, and ~;
outermost layer 92 form the rigid outer layer~ o~
: : the container which do not collapse. Numerous other 0 alternatives are possible.
In:the case of a con~ai.ner with air inlet .
~ vent holes for vacuum dlspensing, the holes must be :~ properly located to insure that the interrlal : : negative dispensing pressure will not pull the ~5 entire panel wall inwardly during vacuum dispensing.
The location and num~er o~ vent holes depends on the :- .
deformation characteristics of the container when i.t :

;UE~STITUTE 6HEElI
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is subjected to internal negative pressure, The deformation characteristics are a function of the container's shape, size, and wall thickness distribution. For proper functionality, the vent holes must be located at the point(s) of maximum deformation and their number depends on the number of such equal potential points. Figs. 15-22 illustrate the proper placement of the vent holes for a number of different container configurations.
Fig. 15 shows a schematic side elevational view and Fig. 16 a schematic cross-sectional view, of a container 100 having a circular panel cross-section. The container 100 includes a ~hread flange 10~, shoulder section 104, panel section 106, and base 108. The panel seotion 106 is the area of -~
maximum deformation under negati~e pressure. For a panel height L and a panel diameter D, where L/D > 1, three vent holes llOA, B, C are required at equally ; spaced points around the circumference, i.e., 120~
apart. An inner layer or liner 11~ will then separate from an outer sidewall layer 116 as shown by dashed lines.
As shown in Figs. 17-18, a container 200 is provided similar to that shown in Figs. 15 16, but having a circular cross-section with three vertical vacuum panel ribs 20l.. For a panel height 1 and a panel ~iameter D, wher~ L/D > 1, three vent holes .
T~T ~ ~ E ~ T

: : :
~, ~ . ,, ~ , : ! . .. . ' , . i WO92/12926 2 ~ ~ 0 7 ~ ~ pcT/us92/noos 210A-C are r~guired at the midpoints between the ribs 201 tagain 120~ apart). An inner layer 214 will then separate from an outer layer 216 as shown by dashed lines.
As shown in Figs. 19-20, a container 300 is provided similar to that shown in Figs. 15-16, bu having a square panel cross section, For the case of a vertical panel height L, and a vertical pane1 width a, where L/a > 1, four vent holes 310A-D are ..
placed at the horizontal and vertical centers of the .
panel sidewalls 312A-~. An inner layer 31g will then separate from an outer layer 316 as shown by dashed lines.
As shown in Figs. 21-22, a container 400 is : 15 provided similar to the container of Figs. 15~16, ~.
but having a rectangular panel cross section. For a panel height L and panels widths a and b ("a"
defining long sidewalls 412A and B, and "b" defining short sidewalls 413A and B), where L/b > 1 and b > a, ; ~ ~0 ~ two vent holes 410A, B are required in the longer :~
: sidewalls 412A and 41~B.
; ; It is readily apparent that the minimum nunoer o~ vent holes can thus be determilled for a ,.
container of any given size or shape.
Although several preferred embodiments o~ :
; the lnvention ~lave ~een specifically illustrated and ;~
described herein, it is to be understood that :

: - :
~ U ~ ~IT ~ ~ E ~

; :

92/12926 21 ~ ~ 7 ~ ~ Pcr/uss2/no~94 variations may be made in the preform construction, mater.ials, the container constructlon and the method of forming the container without departing from the spirit and scope of the invention as defined by the appended claims.
S~hat is claimed is:

. . .

~ , : ~ '' ' ; ~ ~

5UBSTI~I~ITE S~iEET
~: ,

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a dispensing container having a substantially rigid outer body and a flexible collapsible inner bag with the inner bag holding a product to be dispensed, the container having an open end from which the product is dispensed and a closed end, the improvement comprising:
the inner bag and outer body being inner and outer layers respectively of a unitary multilayer expanded plastic preform container, wherein the inner layer is continuous and separate from the outer layer at the closed end of the container and joined thereto at least at the open end, and an opening is provided in the outer layer at the closed end to enable air to enter between the inner and outer layers to facilitate collapse of the inner layer.

2. The container of claim 1, wherein one of the inner and outer layers includes a first layer of a first polymer and the other of the inner and outer layers includes a second layer of a second polymer which at the open end of the container is joined by hydrogen bonding to the first polymer.

3. The container of claim 1, wherein at least one of the layers includes a boundary layer having substantially no tendency to chemically bond or adhere to an adjacent layer.

4. The container of claim 1, wherein the container is adapted to hold a viscous product such as ketchup and the inner layer is collapsible by the application of positive pressure between the inner and outer layers.

5. The container of claim 1, wherein the container is adapted to hold a liquid product such as beverage concentrate and the inner layer is collapsible by the application of negative pressure within the inner layer.

6. The container of claim 1, wherein the inner layer comprises a plurality of layers.

7. The container of claim 1, wherein the outer layer comprises a plurality of layers.

8. The container of claim 1, wherein the inner layer comprises a single layer and the outer layer comprises a plurality of layers.

9. The container of claim 1, wherein vent apertures are provided in the outer layer at the points of maximum deformation of the outer layer to prevent collapse of the outer layer when a vacuum is applied to collapse the inner layer.

10. The container of claim 1, wherein at least one of the inner and outer layers includes a boundary layer, which boundary layer is one of the layers of the multilayer preform.

11. The container of claim 1, wherein the inner and outer layers form a continuous end wall at the open end of the container.

12. A dispensing system comprising the container of claim 1, and means for dispensing a product from the container by causing the inner layer to collapse and dispense a product out the open end of the container.

13. The dispensing system of claim 12, wherein the dispensing means includes means for applying positive pressure through the opening to the inner layer to collapse the inner layer and dispense a product.

14. The dispensing system of claim 12, wherein vent apertures are provided in the outer layer of the body and the dispensing means includes means for applying negative pressure internally to the inner layer to collapse the inner layer and dispense a product, and wherein the vent apertures are located at the points of maximum deformation of the outer layer to prevent collapse of the outer layer.

15. The container of claim 1, wherein one of the inner and outer layers includes a first layer of a first polymer and the other of the inner and outer layers includes a second layer made of a second polymer and adjacent to the first layer, and wherein the second polymer is not substantially melt soluble in the first polymer.

16. The container of claim 15, wherein the other of the inner and outer layers includes a relatively thin boundary second layer as compared to a relatively thick first layer in the one of the inner and outer layers.

17. The container of claim 15, wherein the first polymer is selected from the group consisting of polyester, polypropylene, polyethylene, polyvinyl chloride, polycarbonate, and copolymers and mixtures thereof.

18. The container of claim 17, wherein the second polymer is selected from the group consisting of ethylene vinyl alcohol, polyethylene vinyl alcohol, nylon, and copolymers and mixtures thereof.

19. The container of claim 17, wherein the first polymer is polyester.

20. The container of claim 19, wherein the polyester is substantially polyethylene terephthalate.

21. The container of claim 20, wherein the second polymer is substantially ethylene vinyl alcohol.

22. A squeezable container for dispensing a product comprising:
a dispensing container having a resilient outer body and a flexible collapsible inner bag with the inner bag holding a product to be dispensed, the container having an open end from which the product is dispensed and a closed end, the inner bag and outer body being inner and outer layers respectively of a unitary multilayer expanded plastic preform container, wherein the inner layer is continuous and separate from the outer layer at the closed end of the container and joined thereto at least at the open end, and an aperture is provided in the outer layer at the closed end to enable air to enter between the inner and outer layers to facilitate collapse of the inner layer and form a chamber between the inner and outer layers;
a valve positioned in the aperture having an open position wherein a flow of air into the chamber is allowed and a closed position wherein a flow of air out of the chamber is restricted; and wherein, when squeezed, the outer layer deforms inwardly and the valve remains closed to increase the pressure in the chamber and cause the inner layer to collapse and dispense product out the open end of the container, and when released, the resilient outer layer returns to substantially its original shape causing a reduction in pressure within the chamber which opens the valve and allows air to flow into the chamber to maintain the inner layer in its collapsed state.

.

23. The squeezable container of claim 22, wherein the valve comprises a base portion positioned in the aperture with at least one hole through the base, and a resealable member on the base which is positionable to close the hole when the valve is closed and to open the hole when the valve is open.

24. The squeezable container of claim 22, wherein a second valve is positioned in the open dispensing end of the container to prevent air from entering the inner layer when the outer layer is released.

25. The squeezable container of claim 22, wherein at least one of the inner and outer layers is made of polyester.

26. The squeezable container of claim 25, wherein the polyester is substantially polyethylene terephthalate.

27. The squeezable container of claim 25, wherein at least one of the inner and outer layers includes a boundary layer.

28. The squeezable container of claim 27, wherein the boundary layer is made of a barrier material.

29. The squeezable container of claim 27, wherein the barrier material is ethylene vinyl alcohol (EVOH).

30. The squeezable container of claim 22, wherein the inner layer is a single layer and the outer layer includes a plurality of layers.

31. A squeezable container for dispensing a product comprising:

- 29 - _ - 29 -an integral container body formed by expansion from a multilayer preform, the container body including a main body portion with a plurality of layers and an open dispensing end, the layers including a continuous and collapsible inner layer and a resilient outer layer, the inner layer being joined to the outer layer at least at the open end and separate and apart from the outer layer in at least a portion of the main body to form a chamber between the inner and outer layers as the inner layer collapses, and an external aperture in the main body extending through the outer layer, wherein the inner layer has a tapered wall thickness, decreasing in thickness towards a base end of the container opposite the open dispensing end;
a valve positioned in the aperture having an open position wherein a flow of air into the chamber is allowed and a closed position wherein a flow of air out of the chamber is restricted; and wherein, when squeezed, the outer layer deforms inwardly and the valve remains closed to increase the pressure in the chamber and cause the inner layer to collapse and dispense product out the open end of the container, and, when released, the resilient outer layer returns to substantially its original shape causing a reduction in pressure within the chamber which opens the valve and allows air to flow into the chamber to maintain the inner layer in its collapsed state.

32. The squeezable container in claim 31, wherein the external aperture is in a base end of the container, opposite the open dispensing end.

33. A squeezable container for dispensing a product comprising:
a dispensing container having a resilient outer body and a flexible collapsible inner bag with the inner bag holding a product to be dispensed, the container having an open end from which the product is dispensed and a closed end, the inner bag and outer body being inner and outer layers respectively of a unitary multilayer expanded plastic preform container, wherein the inner layer is continuous and separate from the outer layer at the closed end of the container and joined thereto at least at the open end, and an aperture is provided in the outer layer at the closed end to enable air to enter between the inner and outer layers to facilitate collapse of the inner layer and form a chamber between the inner and outer layers; and a valve positioned in the aperture for restricting a flow of air into and out of the chamber.

34. The squeezable container of claim 33, wherein the valve includes a base portion positioned in the aperture with at least one hole through the base portion, and a resealable member on the base portion which is positionable to open and close the at least one hole.

35. The squeezable container of claim 33, wherein a second valve is positioned in the open dispensing end of the container to restrict a flow of air into the inner layer of the container when the resilient outer layer is released.

36. The squeezable container of claim 33, wherein at least one of the inner and outer layers is made of polyester.

37. The squeezable container of claim 36, wherein the polyester is substantially polyethylene terephthalate.

38. The squeezable container of any one of claims 33 and 37, wherein at least one of the inner and outer layers includes a boundary layer.

39. The squeezable container of claim 38, wherein the boundary layer is made of a barrier material.

40. The squeezable container of claim 39, wherein the barrier material is ethylene vinyl alcohol (EVOH).

41. The squeezable container of claim 33, wherein the inner layer is a single layer and the outer layer includes a plurality of layers.

42. A squeezable container for dispensing a product comprising:
a dispensing container having a resilient outer body and a flexible collapsible inner bag with the inner bag holding a product to be dispensed, the container having an open end from which the product is dispensed and a closed end, the inner bag and outer body being inner and outer layers respectively of a unitary multilayer expanded plastic preform container, wherein the inner layer is continuous and separate from the outer layer at the closed end of the container and joined thereto at least at the open end, and an aperture is provided in the outer layer at the closed end to enable air to enter between the inner and outer layers to facilitate collapse of the inner layer and form a chamber between the inner and outer layers;
a valve positioned in the aperture for restricting a flow of air into and out of the chamber;
and the inner layer has a tapered wall thickness, decreasing in thickness towards a base end of the container opposite the open dispensing end.

43. The squeezable container of claim 42, wherein the external aperture is in a base end of the container, opposite the open dispensing end.

44. A dispensing container having a resilient outer body and a flexible collapsible inner bag with the inner bag holding a product to be dispensed, the container having an open end from which the product is dispensed and a closed end, wherein the inner layer is separate from the outer layer at the closed end of the container and joined thereto at least at the open end, and an aperture is provided in the outer layer at the closed end to enable air to enter between the inner and outer layers to facilitate collapse of the inner layer, and wherein the inner layer has a tapered wall thickness, decreasing in thickness towards a base end of the container opposite the open dispensing end.

45. The container of claim 44, further including a valve positioned in the aperture for restricting a flow of air into and out of the aperture.

46. The container of claim 45, wherein the external aperture is in a base end of the container, opposite the open dispensing end.

47. The container of claim 45, wherein a chamber is formed between the inner and outer layers as the inner layer collapses, and the valve has an open position wherein a flow of air into the chamber is allowed and a closed position wherein a flow of air out of the chamber is restricted, and wherein, when squeezed, the outer layer deforms inwardly and the valve remains closed to increase the pressure in the chamber and cause the inner layer to collapse and dispense product out the open end of the container, and, when released, the resilient outer layer returns to substantially its original shape causing a reduction in pressure within the chamber which opens the valve and allows air to flow into the chamber to maintain the inner layer in its collapsed state.

48. The container of claim 47, wherein a second valve is positioned in the open dispensing end of the container to restrict a flow of air into the inner layer of the container when the resilient outer layer is released.

49. The squeezable container of claim 33, wherein the external aperture is in a base end of the container, opposite the open dispensing end.

50. A method of forming a container, comprising the steps of:
providing an integral plastic multilayer preform (20) having an open end (25), a closed end (24), inner and outer adjacent layers (36, 35), and an aperture (21) formed in the closed end (24) from the exterior of the preform and terminating at the inner layer (36);
expanding the preform (20) to form a container having an integral body (50) with a closed end (52), an open end (60) and a plurality of adjacent layers (36, 35), wherein the preform layers following expansion form a continuous inner layer (36) readily separable from an outer layer (35) at the closed end (52) of the body and joined thereto at least at the open end (60);
collapsing the inner layer (36) to separate the inner layer (36) from the outer layer (35) at the closed end (52) of the body; and returning the inner layer (36) to a position adjacent the outer layer (35).

51. The method of claim 50, wherein the collapsing step comprises applying positive or negative pressure to the inner layer (36) of the container to separate the inner layer (36) from the outer layer (35).

52. The method of claim 50, further comprising, while the inner layer (36) is collapsed, forming vent apertures (41) in the outer layer (35) at the points of maximum deformation when negative pressure is applied internally to the container body.

53. The method of claim 50, wherein one of the inner and outer layers includes a first layer (36) of a first polymer and the other of the inner and outer layers includes a second layer (37) of a second polymer adjacent to the first layer, and wherein the second polymer is not substantially melt soluble in the first polymer.

54. The method of claim 50, wherein one of the inner and outer layers includes a first layer (36) of a first polymer and the other of the inner and outer layers includes a second layer (37) of a second polymer adjacent to the first layer, and wherein at the open end (60) of the container, the first and second polymer layers are joined by hydrogen bonding.

55. The method of claim 50, wherein at least one of the inner and outer layers includes a boundary layer (37) having substantially no tendency to chemically bond or adhere to an adjacent layer (36).

56. The method of claim 53, wherein the first polymer is selected from the group consisting of polyester, polypropylene, polyethylene, polyvinyl chloride, polycarbonate, and copolymers and mixtures thereof.

57. The method of claim 56, wherein the second polymer is selected from the group consisting of ethylene vinyl alcohol, polyethylene vinyl alcohol, nylon, and copolymers and mixtures thereof.

58. The method of claim 56, wherein the first polymer is polyester.

59. The method of claim 58, wherein the polyester is substantially polyethylene terephthalate.

60. The method of claim 59, wherein the second polymer is substantially ethylene vinyl alcohol.

61. The method of claim 53, wherein the second layer comprises a relatively thin boundary layer (37) as compared to a relatively thick first layer (36).

62. The method of claim 50, wherein the container (50) formed is adapted to hold a viscous product such as ketchup and the inner layer (58) is collapsible by the application of positive pressure between the inner and outer layers (58, 59).

63. The method of claim 50, wherein the container (550) formed is adapted to hold a liquid product such as beverage concentrate and the inner layer (556) is collapsible by the application of negative pressure within the inner layer.

64. The method of claim 50, wherein the inner and outer layers (36, 35) form a continuous end wall at the open end (60) of the container.

65. The method of claim 53, wherein each of the inner and outer layers include first layers (36, 40) of the first polymer, and wherein the second layer (37) of the second polymer is adjacent to at least one of the first layers.

,