U.S. patent number 3,823,850 [Application Number 05/376,725] was granted by the patent office on 1974-07-16 for foldable tubular package.
This patent grant is currently assigned to Dart Industries Inc.. Invention is credited to David Edward Ales, J. Keith Brookhart, Maurice A. Ditmars, Warren E. Erickson, Harland Elmer Harms, George Henry Holoubek.
United States Patent |
3,823,850 |
Holoubek , et al. |
July 16, 1974 |
FOLDABLE TUBULAR PACKAGE
Abstract
A laminated settable tubular package is disclosed having
integral end and body portions of the same material. The tubular
package is formed with a process and apparatus which permits head
and shoulder portions to be formed as a continuation of the tubular
body through folding and shaping operations. The package is
substantially impermeable and has particular use for containing
toothpaste, essential perfumes, oils, solvents, flavorings, and
other substances in which permeation of the atmosphere and/or
volatization losses are problems.
Inventors: |
Holoubek; George Henry
(Muscatine, IA), Ales; David Edward (Muscatine, IA),
Harms; Harland Elmer (Muscatine, IA), Erickson; Warren
E. (Muscatine, IA), Ditmars; Maurice A. (Muscatine,
IA), Brookhart; J. Keith (Muscatine, IA) |
Assignee: |
Dart Industries Inc. (Los
Angeles, CA)
|
Family
ID: |
26909226 |
Appl.
No.: |
05/376,725 |
Filed: |
July 5, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
214654 |
Jan 3, 1972 |
|
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Current U.S.
Class: |
222/107; 493/157;
156/218 |
Current CPC
Class: |
B65D
35/02 (20130101); B29K 2023/06 (20130101); Y10T
156/1038 (20150115); B29L 2023/20 (20130101) |
Current International
Class: |
B65D
35/02 (20060101); B65d 035/08 () |
Field of
Search: |
;222/92,107
;93/36.5R,36.5SS,36.8 ;156/69,198,202,204,218,221,226,227
;264/DIG.41 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Reeves; Robert B.
Assistant Examiner: Martin; Larry H.
Attorney, Agent or Firm: Hovet; Kenneth J. Wylie; Paul R.
Taylor; Leigh B.
Parent Case Text
This is a continuation of application Ser. No. 214,654, filed
1/3/72.
Claims
We claim:
1. A collapsible container comprising:
a foldably settable substantially tubular body having an integral
converging shoulder portion and a neck portion of lesser
cross-section than said body, said container characterized as being
a continuum of a flexible settable tubular laminate;
said shoulder and neck portions having uniform spiral folds on the
exterior surface and linear folds on the interior surface said
folds having apices disposed generally at a transition of said body
and said shoulder portion, having inner and outer edge portions
disposed at acute angles with respect to each other, said inner
edge portions being positioned in a manner to substantially define
a plurality of planes when taken in combination with the
longitudinal axis of said container.
2. The container of claim 1 including a plastic covering
mechanically interlocked to said shoulder and neck portions.
3. The container of claim 1 wherein said outer edge portions are
disposed in a common arcuate direction with respect to the
longitudinal axis of said container.
4. The container of claim 3 wherein a substantial portion of said
head is covered with at least three layers of laminate.
5. The container of claim 1 wherein said inner edge portions
comprise two segments, one segment extending from said apices in a
direction forming an acute angle with the longitudinal axis of said
container and the other segment disposed in a direction
substantially parallel with the longitudinal axis of said
container.
6. The container of claim 1, including a plastic covering bonded to
external surfaces of said shoulder and neck portions.
7. The container of claim 6 wherein said folds are bonded
together.
8. The container of claim 6 wherein said integral neck portion and
plastic covering are provided with an orifice therethrough.
9. The container of claim 8 wherein the end of said folds are
covered with said plastic covering.
10. The container of claim 8 wherein said plastic covering includes
means for providing a closure for said orifice.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to tubular containers and, more
particularly, to structural arrangement, method and apparatus
utilized to produce laminated settable tubular packages which are
substantially impermeable to volatile substances and atmospheric
gases.
2. Description of the Prior Art
Various packages have been manufactured for use in containing a
great many products such as toothpaste or the like which may be
conveniently formed as tubular containers or packages. Various
highly viscous products such as toothpaste may progressively be
squeezed from such a package by foldably setting and rolling the
package from the enclosed end toward the dispensing end.
Conventional prior art packages utilized metal foil which, of
necessity, was quite thick and expensive but had the desirable
characteristic of being foldably settable. Such packages composed
completely of metal foil were unsatisfactory in some situations
where the settable material of the metal foil became brittle and
cracked and caused leakage of contents from the package.
Additionally, all-metal packages have been vulnerable to corrosion
by their contents.
Various plastic packages have been used, but many of the
all-plastic packages allow oxidation of products therein and allow
volatile fluids of products to escape through the walls thereof and
consequently an all-plastic package may now serve to contain some
products over a considerable period of time. Furthermore, most
plastic packages are not settable but remain resilient so that they
cannot be conveniently folded and squeezed in such a manner as to
progressively dispense material or products such as toothpaste or
the like.
In accordance with prior art teachings, laminated tubular
structures have been fabricated of sheets of material having a
plurality of lamina wherein metal foil is bonded at its opposite
sides to a polyolefin plastic material such as polyethylene or the
like. These structures have a combination of desirable
characteristics due to the fact that the intermediate metallic
lamina serves as a barrier for volatile fluids and oxygen as well
as to provide for a settable structure which may take a set when
folded and hold the plastic lamina in folded condition such as is
desirable in the progressive use of a toothpaste tube or the like
which is typically progressively folded as the contents are
dispensed therefrom. These structures also prevent corrosion of the
metallic lamina since it is protected on both inner and outer sides
by plastic material. Furthermore, the outermost polyolefin lamina
is readily receptive to printing for the purpose of applying
labels, trademarks, or other indicia on the outer sides of the
hollow tubular wall structures.
Accordingly, the laminated tubular wall structures include many
desirable characteristics and have therefore become quite versatile
in the packaging of a great variety of products which may be
oxidizable, corrosive to metal, or which may have volatile
materials which tend to escape through plastics; and further, these
laminated materials are readily mechanically settable and readily
receptive to printing of indicia on the outer sides thereof.
Moreover, these laminated wall structures are relatively economical
since a relatively small amount of metallic foil may be used with
one or more thin economical lamina of polyethylene or the like on
inner and outer sides of the metal foil.
The laminated structures including two lamina of plastic and one
lamina of metal foil can be produced in sheet stock. Due to the
relative thicknesses of the lamina and the requirement for accuracy
relative thereto, it has been found most economical to produce such
materials in sheet stock and then to form the sheet stock into
tubular wall structures by butting the edges, or forming an
overlapping seam, and then heating with or without the addition of
other thermoplastic material to provide a fused seam.
The prior art includes numerous patents disclosing laminated
tubular wall structures with metal foil barrier lamina and wherein
several separate barrier structures are required in the shoulder
and neck area of the prior art packages, and the production of such
packages utilizing several barrier parts has been relatively
complicated and costly.
When several metallic lamina barrier parts are utilized in the
shoulder and neck area of a toothpaste tube or the like, it is
difficult to produce such structures accurately and to bond the
various parts together in such a manner as to prevent oxidation of
the product and to prevent the escape of volatile materials from
products contained in the packages.
SUMMARY OF THE INVENTION
According to the present invention, there is provided a novel
laminated and foldably settable tubular package having a tubular
body including a laminated tubular wall structure with an integral
shoulder and neck structure formed of folded portions which extend
from the tubular body throughout the shoulder and neck area of the
package to form a relatively thick shoulder and neck structure
wherein at least three layers of the wall structure are disposed in
the folded portions and in the shoulder and neck area of the
package, and thereby maintain continuity of laminated plastic and
metal lamina through the body, shoulder, and neck areas of the
package.
The package of the invention includes an annular row of folded
portions, preferably formed as acute triangles, of a laminated
tubular body, and these folded portions are uniformly folded in an
annular row and are all disposed in the same direction so as to
provide strength as well as uniform structural continuity of
plastic as well as a metal barrier lamina. With this structure, the
entire body area as well as the shoulder and neck areas of the
package can have foldable and settable characteristics as well as
resistance to corrosion; and further, the metal barrier lamina
prevents the escape of volatile fluids from the product and
prevents oxygen from reaching the product through the plastic
lamina.
The invention includes a novel method for producing a laminated and
foldably settable tubular package which employs progressive
formation of an annular row of crimped portions adjacent the open
end of a laminated tubular body and subsequent positioning of the
crimped portions into a row of acute triangular folded portions,
all disposed in a substantially frusto-conical assembly of folds.
In its preferred form, the method includes the forming of said
triangular folded portions into an annular row in which the folded
portions are all positioned, and preferably twisted and rotated in
the same general direction around the axis of said frusto-conical
assembly. Further, in its presently preferred form, the method
includes subsequent positioning of the frusto-conical assembly to
deform it into one in which it is inverted into a frusto-conical
recessed shape with a central frusto-conical generally tubular
portion integral therewith and in opposed disposition. This latter
operation is done preferably by conforming dies in opposition to
each other. The preferred method further includes a process step of
the type disclosed in U.S. Pat. No. 3,047,910 to Downs in which a
hot disc of plastic is placed under pressure by means of dies at
said frusto-conical recess portion, and opposed frusto-conical
tubular portion, of said folded portions whereupon the hot plastic
under pressure is thermally and mechanically formed into an end
portion which surrounds the shoulder and neck portion of the
package of the invention and wherein an ofifice and means for
providing a closure are thermally and mechanically formed in
surrounding relation with the neck portion of the package by
compression molding. Alternatively, a plastic end piece can be
applied by injection molding or other suitable processes.
The invention also preferably includes the use of unique dies and
apparatus for the aforementioned crimping process as well as the
twisting and folding process, and for forming the inverted or
recessed frusto-conical and opposed concentric frusto-conical
configurations preliminary to the forming and fusion of the end
piece or member on the shoulder and neck structure formed by the
folded portions which are integral with the tubular body structure
of the package. The folded portions of the package of the invention
at the shoulder and neck portions thereof, include at least three
contiguous layers of the laminated wall structure so that the
shoulder and neck portions of the package of the invention are
quite strong and rigid and extend such that there is complete
continuity of the plastic and metallic lamina throughout the body,
shoulder, and neck areas of the package.
The uniform crimping and crimp twisting operations, in accordance
with the invention, are particularly important when pre-forming the
shoulder and neck portions relative to a laminated tubular wall
structure which is initially formed of sheet stock and provided
with a longitudinal seam. The preferred crimping and fold twisting
operations, in accordance with the invention, insure uniform
crimping and folding of laminated wall structures even though they
have relatively thick, stiff seams, all of which allows all of the
lamina, as well as the metallic barrier lamina, to extend uniformly
and in continuity throughout the body, shoulder, and neck areas of
the package of the invention.
OBJECTS
Accordingly, it is an object of the present invention to provide a
novel laminated and foldably settable tubular package having a
laminated wall structure including plastic and barrier lamina which
extends throughout the body, shoulder, and neck area of the package
and wherein folded portions are uniformly disposed in the shoulder
and neck area of the package of the invention to provide for
continuity throughout the body, shoulder, and neck area of the
plastic lamina as well as the barrier lamina.
Another object of the invention is to provide a novel method and
apparatus for forming a laminated and foldably settable tubular
package which may be effectively used for containing and dispensing
a great variety of viscous products such as toothpaste or other
materials.
Another object of the invention is to provide a method and
apparatus for forming a tubular package which is particularly
adapted for accurately and uniformly crimping, folding, and forming
a shoulder and neck structure integral with a tubular body having a
plurality of lamina originally formed from sheet stock.
Another object of the invention is to provide a novel laminated and
foldably settable tubular package having specifically novel folded
structure in the shoulder and neck areas thereof, which promotes
facility and economy of manufacture, reliability of manufacture and
efficiency in the production and maintenance of a uniform and
continuous metallic barrier lamina and plastic lamina throughout
the body, shoulder, and neck areas of a package and throughout all
areas therein where the product may be contained in contact with
the package.
Further objects and advantages of the product and the method
disclosed herein may be obvious from the following specification,
appended claims, and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an exemplary tubular wall
structure.
FIG. 2 is an enlarged fragmentary sectional view taken on line 2--2
of FIG. 1;
FIG. 3 is a fragmentary sectional view showing a crimping die
performing a crimping operation according to the invention on a
laminated tubular wall structure;
FIG. 4 is a fragmentary perspective view of a crimping die as shown
in section in FIG. 3 of the drawings;
FIG. 5 is a fragmentary perspective view of a crimped end of a
hollow tubular wall structure following the operation shown in
FIGS. 3 and 4 of the drawings;
FIG. 6 is a fragmentary sectional view of a crimp twisting die
structure showing the crimped tubular wall structure disclosed in
FIG. 5 in position to be twisted into the shape shown in FIG.
8;
FIG. 7 is a fragmentary sectional view taken from the line 7--7 of
FIG. 6 showing details of the crimp twisting die;
FIG. 8 is an enlarged perspective view of a tubular wall structure
similar to that as shown in FIG. 5 but following the crimp twisting
operation thereon by means of the dies as shown in FIGS. 6 and
7;
FIG. 9 is an enlarged fragmentary sectional view taken from the
line 9--9 of FIG. 6 and showing a section of the crimp folding and
twisting die;
FIG. 10 is a fragmentary sectional view of dies and of the part
shown in FIG. 8 being deformed further to convert the
frusto-conical assembly of folded portions as shown in FIG. 8 to
the form shown generally in FIGS. 10 and 11;
FIG. 11 is a fragmentary sectional view showing a preferred process
step subsequent to that shown in FIG. 10;
FIG. 12 is a sectional view taken from the line 12--12 of FIG. 10
showing an end of the tubular wall structure as formed in the dies
disclosed in FIG. 10;
FIG. 13 is a fragmentary sectional view of dies and an end product
of the invention wherein the final processing step is
performed;
FIG. 14 is an enlarged fragmentary sectional view of acute
triangular folded portion of the preferred form of the invention
which can form a structure extending throughout the shoulder and
neck area of the package of the invention and generally as formed
in the step shown in FIG. 6 and illustrated in FIG. 8;
FIG. 15 is an enlargd fragmentary axial sectional view of the
completed shoulder and neck portions of the invention with a
closure cap thereon;
FIG. 16 is an enlarged fragmentary sectional view taken from the
line 16--16 of FIG. 15;
FIG. 17 is an enlarged fragmentary sectional view similar to FIG.
15 but showing a modification of the invention.
PREFERRED EMBODIMENTS OF THE INVENTION
As shown in FIG. 1 of the drawings, the invention comprises a
hollow tubular wall structure 30. This hollow tubular wall
structure 30 can be provided with a longitudinal seam 32 but also
may be formed as a tube with a spiral seam. The seam can be a fused
lapped seam or one that has been folded and sealed or one utilizing
a sealing strip or other adhesive material. The specific type of
seam used will generally be dictated by the lamina compositions,
their thickness, and the characteristics of the material to be
contained within the tubular package. The same criteria is
applicable in choosing a particular laminate for use in
constructing the tubular package of the present invention. Any of
the particular compositions known and used in the art and any
number of layers and combination of metal foil, fiber, paper, and
plastic material which are foldable, settable, and substantially
impermeable to the products contained, are suitable for use as
lamina in the present invention. Exemplary of suitable plastic
materials are polyethylenes, polyvinylchlorides, polyvinylidene
chlorides, polyvinyl acetates, polypropylenes, nylons,
polyacrilonitrile, copolymers of the above, copolymers of ethylene
and acrylic acid, and the like. The compositions, number of lamina,
and their location with respect to each other in forming the
laminate used in the tubular package are not deemed to be part of
the novel aspects of the present invention. It is desirable,
however, that an outer surface of the tubular body comprise a
material that can bond together when the laminate is folded upon
itself and formed into head and shoulder portions. It is also
desirable that the outer surface be bondable to a plastic end piece
which may be subsequently molded thereto. This is not critical,
however, because a mechanical interlock can result when plastic
material is forced upon the folded portion during formation of the
end piece.
An example of a three-layered laminate is shown in FIG. 2 of the
drawings wherein the wall structure of the tubular structure 30
comprises an inner lamina 34, an intermediate lamina 36, and an
outer lamina 38. The intermediate lamina 36 can be a metal foil
such as lead or aluminum, and the lamina 34 and 38 may be flexible
plastic lamina such as a thermoplastic polyolefin, as for example,
polyethylene, polypropylene, nylon, polyurethane, polyester, or the
like, as described above.
The lamina 34 is disposed on the inner side of the tubular wall
structure 30, while the lamina 38 is disposed on the outer side of
the tubular wall structure 30, the inner side of the tubular wall
structure 30 being designated 40 and the outer side being
designated 42.
The lamina 34 at the inner side prevents corrosive material from
attacking the metallic lamina 36 while the plastic lamina 38 on the
outer side 42 is compatable with many materials used for printing
of indicia on the outer sides of packages such as toothpaste tubes
or the like.
The metallic lamina 36 is capable of acting as a barrier to the
passage of fluids from a product at the inner side 40 and prevents
the migration of oxygen from the atmosphere through the lamina 34
and 38 and into the product on the inner side 40.
The plastic lamina 34 and 38 are pliable but somewhat resilient,
while the metallic lamina 36 is foldably settable and of sufficient
thickness relative to the lamina 34 and 38 so that the tubular wall
structure 30 may be folded flat and then rolled up in folded
condition in a manner common to the well known metallic toothpaste
tube, so that the package of the invention, as will be hereinafter
described, may be used to dispense contents therefrom in a manner
similar to the well known practice of metallic squeeze tubes of the
type that are commonly used for toothpaste. It will be appreciated,
however, that since the plastic lamina 34 and 38 are on both inner
and outer sides of the metallic lamina 36, fracture of the metallic
lamina 36 is not liable to occur and is of minor importance since
in the event such fracture does occur it will most likely be in the
area of tightly folded portions and will not permit leakage due to
the existence of the plastic lamina 34 and 38 at opposite sides
thereof. It will be understood that in certain instances where the
foregoing considerations are not important, a laminate having only
a single plastic layer bonded to the outer surface of a barrier
layer can be used. Moreover, laminates having additional layers of
metal, paper, and plastics can also be used.
The laminated tubular wall structure 30 is provided with opposite
open ends 44 and 46 as shown in FIG. 3 of the drawings. A male
mandrel 50 having a shoulder 52 is inserted into the interior of
the tubular wall structure 30 to a position wherein the open end 46
thereof rests on the shoulder 52 of the mandrel 50. The mandrel 50
is provided with a substantially flat end 54 at right angles, and
during the operation shown in FIG. 3 a crimping die assembly such
as shown in FIGS. 3 and 4 is placed in surrounding relation with
the outer side 42 of the hollow tubular wall structure 30. The die
assembly 56 is provided with a sleeve 58 having a bore 60 closely
conforming with the outer side 42 of the hollow tubular wall
structure 30. Mounted to the sleeve 58 are a plurality of fingers
62 which are pivotally held by a circular ring 64 in notches 66 of
such fingers 62. The fingers 62 are provided with edge portions 68
directed inwardly toward the outer side 42 of the tubular wall
structure 30 near the open end 44 thereof. A die sleeve 70 is
slidably movable on the die 58 in the direction of the arrow A as
shown in FIG. 3 of the drawings, so as to pivotally force the
fingers 62 inwardly to deform the tubular wall structure 30 into
the shape as shown in FIG. 5 of the drawings. The fingers 62 are
uniformly spaced in an annular row around the axis of the mandrel
50 and they are disposed, when moved inwardly by the ring 70, to
present a substantially frusto-conical disposition relative to each
other so as to form a frusto-conical crimp at the end 44 of the
tubular wall structure. The equal spacing of the fingers 62
provides for evenly spaced undulated crimp portions 72 as shown in
FIG. 5 of the drawings at said open end 44, and these crimped
portions 72 are provided with terminus portions 74 which terminate
on the tube 30 at a location substantially at the end 54 of the
mandrel 50 which restricts the formation of the crimps when the
fingers 62 are moved and cammed inwardly from broken line positions
76 to the solid line positions 78, shown in FIG. 3 of the
drawings.
As shown in FIG. 5 of the drawings, the crimped portions 72 are
disposed generally in the frusto-conical form and while they are
held in this form, as shown in FIG. 3 of the drawings, by the
sleeve 70 as it is moved into a broken line position 80, the male
die 50 is removed and heat can be applied internally of the tubular
wall structure 30 if desired to effect thermal setting of the
lamina 34 and 38 so as to ensure retention of the uniformly spaced
annular row of crimped portions 72 as shown in FIG. 5. These
crimped portions 72 are provided with radially extended singular
portions 82 which, according to a further process step of the
invention, are twisted into complete folded portions.
As shown in FIG. 6 of the drawings, the crimped tubular wall
structure 30 in the crimped condition as shown in FIG. 5 is again
positioned on the male die 50 and abutted at the end 46 with the
shoulder 52 of the male die 50. The end 54 of the male die 50
coincides generally with the terminus portion 74 of the crimped
portions 72 and a female die 84 closely conforms to and surrounds
the outer side 42 of the tubular wall structure 30. The die 84 is
provided with an enlarged pilot bore 86 wherein a crimp folding die
88 is rotatably mounted. The die 88 is provided with radially and
axially recessed portions 90 with intermediate ridges 92, also
shown in FIG. 9 of the drawings. The undulated crimped portions 72
coincide in number with the recess portions 90 of the die 88 and
the radially extended partially folded crimped portions 82, shown
in FIG. 5, are engaged in the corresponding recesses 90 and the die
88 can be moved slightly in the direction of the arrow B shown in
FIG. 6, while being rotated in either direction as shown by arrow
C, thus rotatably twisting the partially crimped portions 82 into
fully folded crimped portions 94 as shown in FIG. 8 of the
drawings. It will be seen that inasmuch as the die 88 is rotated in
either of the directions of the arrow C, all of the partially
folded crimped portions 82 will be twisted and rotatably folded in
the same direction, and formed into a uniformly folded
frusto-conical form as shown in FIG. 8, wherein each folded portion
94 is preferably an acute triangle having an apex portion 96
generally located between the hereinbefore described terminus
portions 74 which were formed at the end 54 of the die 50. Thus,
each folded portion 94 has an apex which coincides with the
perimeter of the hollow tubular laminated wall structure 30 and the
annular row of folded portions 94 is of considerably smaller
diameter than the outside diameter of said hollow tubular wall
structure 30 when formed as shown in FIGS. 6 and 8 of the
drawings.
When considering the structure of the hollow tubular wall structure
30, and particularly those having heavy seams such as seam 32, the
operation of the dies and method disclosed in FIGS. 3 and 6 is very
important. Inasmuch as the seam 32 as shown in FIG. 1 is relatively
stiff compared to the remainder of the tubular wall structure 30,
it is very important that the crimping performed as shown in FIG.
3, and resulting as shown in FIG. 5, be precisely accomplished and
uniformly finished to obtain a uniform result. Subsequently, it is
important that all of the crimped portions be uniformly engaged by
the die 88 or by equivalent means for uniformly twisting and
folding the crimped portions 72 and 82 into the completely folded
portions and particularly into an annular row in which the folded
portions all extend uniformly in the same direction, and wherein
these crimped portions become folded into acute triangular portions
with their apices generally terminating at the perimeter of the
hollow tubular laminated wall structure. In furtherance of the
above objectives, it is important that first contact and inwardly
forward motion of the fingers 62 to the tube be at a location below
the tube end 44, generally a distance equal to at least half the
tube diameter. The tube resistance to bending at this point
maintains the folds under tension and, as the fingers move toward
the center, wrinkles are prevented thereby insuring uniform and
repeatable folds.
As shown in FIG. 10, the crimped and folded structure of the
tubular wall structure disclosed in FIG. 8 may be further formed by
a male die 98 that is similar to the die 50 and provided with a
stop shoulder 100 on which the open end 46 of the hollow tubular
wall structure is disposed after it has been formed, as shown in
FIG. 8 of the drawings. The male die 98 is provided with a die
portion 102 which may be made of hard metal or relatively soft or
resilient material such as rubber or the like, and this die portion
102 is provided with an annular frusto-conical recess 104 which is
inverted and extends convergingly into the die portion from a
peripheral end 106 thereof. The die portion 102 is provided with a
central concentric frusto-conical portion 108 which is concentric
to the inverted frusto-conical portion 104 and the end of this
concentric or central frusto-conical portion is designated 110 and
extends into substantially an axial position coinciding with the
peripheral end 106 of the die portion 102.
The die portion 102, as well as the male die 98 which carries it,
conforms closely to the inner side 40 of the hollow tubular wall
structure 30. The outer side of the hollow tubular wall structure
30 is surrounded by cylindrical die 112 having a bore 114 which
closely conforms with said outer side 42 of the tubular wall
structure 30. A second forming die 116 is provided with a die
portion 118 having a shape complemental to that of the die portion
108 and this complemental portion comprises a generally
frusto-conical recess portion 120.
The frusto-conical recess 120 generally conforms to the
frusto-conical die portion 108 and the frusto-conical recess 120 is
adapted to surround and fit over the annular row of folded portions
94 as shown in FIG. 8, when that structure is placed in the die
112, and when the die 116 is moved in either direction of arrow C
in FIG. 10 of the drawings. The die portion 118 is also provided
with a frusto-conical portion 122 which generally conforms to the
inwardly directed frusto-conical recess 104 of the die portion 102
so as to deform the folded portions 94 into the general
cross-sectional shape as shown in FIG. 10 of the drawings so that
ends 124 of the folded portions 94 are extended a distance about
equal to or less than a common plane of the apices 96 of the folded
portions 94. After being formed in accordance with the foregoing, a
head piece is integrally applied to the tube by a process
preferably similar to that described in U.S. Pat. No. 3,047,910 to
Myron H. Downs. Alternatively, the head pieces can be applied by in
situ injection molding, fusing of previously injected molded head
pieces, or other compatable processes. In the preferred process,
the tubular wall structure 30 is removed from the dies 98 and 112
and placed onto a mandrel 128.
The mandrel 128 and tube 30 are positioned within a punch die 126
which is provided with an annular cutting edge 130. This cutter,
having an edge 130, cuts through a strip of hot plastic designated
132 in FIG. 11 of the drawings leaving a disc 134 of the hot
plastic adhering by the heat thereof to the apices 96 and ends 124
of tube 30. The folded portions 94 are formed into a generally
frusto-conical tubular form as shown in FIGS. 10 and 11, so that
this frusto-conical tubular form is adapted to receive a
cylindrical pilot 136 of the mandrel 128. This mandrel or male die
128 is provided with an angular sloping shoulder 138 extending from
its perimeter to the reduced diameter punch portion 136 which is
adapted to move into the generally frusto-conical tubular portion
formed by the folded portions 94 as shown in FIG. 11.
As shown in FIG. 13, the mandrel or male die 128 is placed in a
head forming die 140 and moved in the direction of an arrow E in
the hollow tubular wall structure 30 so as to force the cylindrical
punch 136 through the frusto-conical tubular portion which is
disposed centrally and defined by the folded portions 94. Thus the
hot plastic 134 is forced under pressure into a cavity 142 which
generally conforms to the shape of the shoulder 138 and the punch
136. The cavity 142 is provided with thread forming portions 144
surrounding the neck area of the package of the invention which is
formed from the frusto-conical tubular section of the folded
portions 94 which causes the frusto-conical tubular folded portions
to be formed around the straight cylindrical punch 136 and to
become a straight wall tubular neck portion 146 as shown in FIG. 15
of the drawings.
When the die 128 at its shoulder 138 forces the folded portions 94
to conform therewith, the triangularity of the folded portions are
deformed around the punch 136 and become more nearly parallel in
this area, and the folded portions 94 are then substantially as
shown in FIGS. 15 and 16. The folded portions 94 are shown on
enlarged scale in FIG. 14 and are illustrated in FIG. 14 in
somewhat the same state of disposition as they are shown in FIG. 8
of the drawings; however, the illustration in FIG. 14 is intended
to amplify the disclosure due to large scale for the purpose of
clarifying the entire structure as illustrated.
It will be appreciated that when the hot plastic 134 is formed
under pressure onto the outer side portions of the folded portions
94, the outermost plastic layer 38 becomes plastically bonded to
the plastic 134 and that it is caused to flow into the general
cross-sectional shape as indicated in FIGS. 13 and 15, to form an
end member having a shoulder covering portion 148 and a neck
surrounding portion 150 comprising helical screw thread portions
152 formed by the screw thread forming portions 144 in the die 140.
Other neck configurations may be formed, such as flanges, depending
on the type of closure means being utilized.
Integral with the punch 136 is a reduced diameter orifice forming
pin 154 which is punched through the plastic 134 and passes through
an opening 156 in the die 140. The die 140, together with the
travel of the punch 128, is so arranged that an end portion 158 of
the punch 136 stops in spaced relation to a corresponding cavity
portion 160 in the die 140 so as to leave an end cover portion 162
which is disposed over the ends 124 of the folded portions 94 and
this end portion 162 is provided with a product dispensing opening
164 which is left by the pin 154 of the punch 128 as it is
retracted from the opening 156 and out of the hollow tubular wall
structure 30.
Accordingly, it will be appreciated that all of the folded portions
94 can be finally pressed tightly together and due to the heat of
the plastic 134 and/or the pressure of the punch 128 and die 140,
the folded portions 94 are contiguously folded together so that the
end member 162 is efficiently bonded at its shoulder portion 148
with a shoulder area 166 of the folded portions 94, this shoulder
area being integral with the hollow tubular wall structure 30 and
also integral with the cylindrical neck portion 146 hereinbefore
described. Heat from external sources can be applied to effect such
bonding, if desired. It is further contemplated that plastic
material flows about the edges of the folds thereby forming
mechanical bonding with the folded portions.
A closure cap 166 is engaged with the screw threads 152 as shown in
FIG. 15, and the gasket 168 is held in the cap 166 over the
dispensing opening 164 to prevent the escape of materials from the
interior of the package of the invention as shown in FIG. 15. The
use of a cap liner, however, is optional and frequently plastic
caps do not require such.
As shown in FIG. 14, each triangularly folded portion at its apex
96 generally coincides with the perimeter of the hollow tubular
wall structure 30, shown in FIG. 15, and opposite U-shaped folded
edge portions 170 and 172 are disposed at acute angles to each
other extending from apices 96 in a diverging relation to the
divergent ends of the folded portions 94, all as shown best in FIG.
14.
With reference to FIG. 16, the U-shaped folded diverging edge
portions 170 and 172 can be seen and it will be apparent that each
U-shaped folded edge portion 170 is in close proximity to an
adjacent folded edge portion 172, the edge portion 172 being on the
outer sides of the neck structure while the edge portions 170 are
on the inner side of the structure, as shown best in FIGS. 14 and
15 of the drawings.
The folded portions 94, being of at least three layers of the
laminated wall structure, reinforce the shoulder portion 166 and
the neck portion 146, as shown in FIG. 15, and provide a mechanical
arrangement by means of which all of the lamina 34, 36, and 38
extend in complete uninterrupted continuity throughout the tubular
wall structure 30, the shoulder structure 166 and the hollow
cylindrical neck structure 145. The manner in which these folded
portions 94 are disposed permits them to be formed without rupture
and to be formed even though the seam 32 is relatively thick in one
peripheral area of the hollow tubular wall structure 30.
Additionally, it will be observed from FIG. 16 that each layer of
each folded portion 94 contains three lamina, namely, the lamina
34, 36, and 38. It will be noted from FIG. 16 that the lamina 38 is
folded against itself and is disposed generally at the outer side
of the neck structure 146 while the lamina 34 is disposed generally
at the inner side of the neck structure 146, and is also folded
against itself so that all of the folded portions 94 are nine
laminations thick and are very rigid, and since all of the plastic
lamina fold against each other, pressure and heat provides for good
bonding of these folded portions together when the hot plastic disc
134 is bonded to the folded portions 94 in a manner as shown in
FIG. 13 of the drawings, and as hereinbefore described.
In the modification as shown in FIG. 17, the hot plastic disc 134
is not formed onto the neck and shoulder structure of the
invention, but rather the folded portions 94 only are used to form
a modified neck structure 174. This neck structure is provided with
helically rolled screw threads having helical outward protrusions
176 and correspondingly intermediate recess portions 178 on the
inside of the neck structure 174. Moreover, due to the thickness of
the folded portions, it is possible to reduce somewhat the
thickness of head piece 162.
It will be appreciated that when the folded portions 94 are formed
into helical screw threads 176, the nine laminations in the folded
portions 94, as shown in FIG. 16, are formed into a very rigid neck
structure capable of holding a cap 180 and a gasket 182 therein, to
enclose contents within the interior of the package of the
invention. To form such a product, it can be advantageous to use
relatively thicker layers of metal and/or plastic and to apply heat
at various stages of the process to provide, for example, thermally
set crimps or folds.
The lamina 34, 36, and 38 are thin structural layers of plastic and
aluminum or lead foil, and as a specific example, the lamina 34 and
38 may be 0.005 to 0.006 inches thick, while the lamina 36 may be
0.001 inches thick and may be made of metal foil such as aluminum
or lead. The lamina 34 and 38 may be made of a polyolefin material
such as polyethylene or the like; however, the foregoing materials
and dimensions may be varied according to the size and other
characteristics of the package to be produced.
It will be obvious to those skilled in the art that the
three-to-one ratio of the folded portions relative to the laminated
sidewall portions of the package provides for a fairly substantial
ratio of thickness and/or strength between the sidewall portion and
the shoulder 166 and neck 146. Accordingly, it will be appreciated
that the thickness of the lamina 36, as well as the relative
thicknesses in the lamina 34 and 38 may be varied, as desired, to
adjust the mechanical characteristics of the tubular structure; as
for example, when the metallic lamina 36 is relatively thicker, its
influence over the relatively resilient plastic lamina 34 and 38
becomes apparent relative to the intermittently progressive setting
of folds at the end of a package such as a toothpaste tube or the
like constructed in accordance with the present invention.
It will be seen that the folded portions 94 in areas of the tubular
wall structure 30, as well as the shoulder area 166, and the neck
area 146, maintains complete continuity of all of the lamina 34,
36, and 38, to provide for the prevention of escape of volatiles
from the interior of the container outward, or to prevent the
migration of oxygen from the atmosphere to products inside the
package, and furthermore the outer lamina 34 is very receptive to
various materials used for printing labels or other indicia on the
outer sides of packages such as toothpaste tubes or other similar
packages. While a tubular container has been discussed, containers
of other geometric configurations can be used wherever the
processing techniques of the invention will be advantageous.
It will be obvious to those skilled in the art that various
modifications may be resorted to without departing from the spirit
of the invention.
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