US3565293A

US3565293A - Collapsible tube

Info

Publication number: US3565293A
Application number: US714471A
Authority: US
Inventors: Robert Stephen Schultz
Original assignee: American Can Co
Current assignee: Rexam Beverage Can Co
Priority date: 1968-03-20
Filing date: 1968-03-20
Publication date: 1971-02-23
Anticipated expiration: 1988-02-23
Also published as: SE333897B; DE1761596B2; NL6812190A; NO122004B; GB1219481A; CH495887A; DE1786644C2; BR6899279D0; NL157268C; NL157268B; DE1761596C3; DE1761596A1; DK146713C; DK146713B; FR1570241A; BE719719A

Abstract

A collapsible tube construction having a thermoplastic headpiece united to a preformed body, with improved barrier means associated with the headpiece whereby product permeation and oxygen absorption through the headpiece are minimized.

Description

I United States Patent 1111 3,565,293

[ 72] Inventor Robert Stephen Schultz 1 56] References Cited Mizldlesex County, NJ. UNITED STATES PATENTS 1 1 pp 71 1 2,605,018 7/1952 Croce etal. 222/107 [221 FM Mar-20,1963 3,093,255 6/1963 Mesrobian m1. 215/15 [45] Patented Feb-23,1971 3,260,411 7/1966 Dobson 222/107 [731 Asslgnee Amman Cmlmy 3,295,725 1/1967 Brandt 222/107 New 3,393,087 7/1968 Kamp et a1 1. 215/1.5x

Primary Examiner-Robert B. Reeves Assistant Examiner-Frederick R. l-iandren Attorneys-Kenneth H. Murray, George P. Ziehmer, Robert [54] COLLAPSIBLE TUBE P. Auber and LOUIS F. Heeb 11 Claims, 6 Drawing Figs. [52] US. Cl 221/1017 ABSTRACT: A collapsible tube construction having a ther- [51] lnt.Cl. ..B65 d 35/12, moplastic headpiece united to a preformed body, with im- B65d 35/14 proved barrier means associated with the headpiece whereby [50] Field of Search 222/ 107, product permeation and oxygen absorption through the headpiece are minimized.

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I i "I 1 i l INVENTOR. ROBERT STEPHEN SCHULTZ ATTORNEY coLLArsrsLE TUBIE BACKGROUND OF THE INVENTION This invention is an improvement in the art of collapsible tubes, and in particular in tube constructions which use some thermoplastic materials susceptible to product permeation and oxygen absorption, e.g. polyethylene. Examples of this type of collapsible tube are found in U.S. Pat. Nos. 3,260,410 and 3,260,41 1, and 3,295,725, in which are illustrated various constructions designed to minimize the problems associated with the permeable character of the thermoplastic materials used in these constructions.

The present invention is concerned with the same problem, and relates to another approach by which improved product protection and preservation are achieved.

SUMMARY OF THE INVENTION A collapsible dispensing tube havinga thermoplastic headpiece united to one end of a tubular body of impermeable material. A barrier member of impermeable material is associated with the headpiece to prevent product loss or oxygen absorption through the thermoplastic material in the headpiece. Means are provided on the barrier member which imbed in the inside surfaces of the headpiece to secure the tow components together.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary side elevational view, party in section, of a collapsible tube embodying the invention.

FIG. 2 is an enlarged fragmentary sectional view of an upper portion of the tube of FIG. 1.

FIG. 3 is a top view of the barrier member which is an element of the invention.

FIG. 4 is a side view, partly is section, of the barrier member, taken along line 4-4 of FIG. 3.

.FIG. 5 is a fragmentary side elevational view, partly in section, of a modified form of the invention.

FIG. 6 is a sectional view through a typical molding apparatus used in the manufacture of the tubes of this invention, showing on the left-hand side the arrangement of tube members prior to the final molding step and on the right-hand side molten plastic filling the mold cavity.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. I, there is illustrated a collapsible tube comprising a body 10 connected at its upper end to a headpiece 15, and a disc-shaped barrier insert 20 interiorly associated with the headpiece.

The body 10 may be of any suitable material capable of containing and protecting the contents of the tube. By way of illustration, the body is shown in FIG. 2 as a well-known laminated construction, comprising an exterior layer 11 of thermoplastic material such as polyethylene, an intermediate barrier layer 12 of impermeable material such as aluminum foil, and an interior layer 13 of a thermoplastic material which is compatible with the tube contents and also capable of thermally uniting with the headpiece 15 at the joinder at the top end of the tube body. Layer 13 may be polyethylene, or a composite of several layers of different materials selected for good adhesion to the foil layer as well as good product compatibility and protection. Layer 11 also may be a composite of different layers, such as for example, a layer of clear polyethylene over a layer of printed paper or printed polyethylene. The advantages and characteristics of such body constructions are described in detail in the aforesaid U.S. patents.

The headpiece 15 is of a readily moldable thermoplastic material, such as polyethylene, and includes a neck portion 16 appropriately threaded to receive a screw cap (not shown) and a breast portion 17 which is adhered or welded about its peripheral band area 18 to the upper interior wall of tube body 10. An annular lip portion 19 of the headpiece extends inwardly from band portion 18 to underlie the edge of disc 20. As mentioned before in reference to the laminated body construction of FIG. 2, the thermoplastic materials of the head piece 15 and the interior layer 13 of the body are capable of thermally uniting under selected manufacturing procedures in the band area 18.

As best shown in FIGS. 3 and.4, insert disc 20 includes a conical portion 22 which conforms with the interior shape of headpiece breast portion 17, and an upstanding annular portion 21 which conforms to the interior shape of the headpiece neck 16. The peripheral edge 23 of the conical portion 22 is beveled at an angle approximately parallel with the axis of the tube body. The exterior surface of 'the annular portion 21 of the disc 20 preferably includes raised means or spaced projections which assist in securing the disc to the inner surfaces of the headpiece 15. This may take the form of circumferential rings 24 and axial ribs 25 on the annular portion 21. Similar rings 26 and ribs 27 may be used'on the conical portion 22, if desired for added securement, although in most applications it is not believed necessary. Alternately, the raised means may take the form of serrations or other types of spaced projections on the upper surface of either or both the conical and annular portions of the disc, such means being capable of imbedding in the inner surfaces of the headpiece to secure the two members together.

Insert disc 20 is made from a material having very low permeability, since its function in the tube structure is to minimize as much as possible the oxygen absorption and product migration through the headpiece 15. Preferably the disc material is moldable plastic material selected for its impermeable character as well as product compatibility. Suitable materials are the amino resins, such as urea formaldehyde. Certain thermoplastic materials noted for their impermeable character are polypropylene and the polyamides such as nylon. Other plastic materials, both thermosetting and thermoplastic, having the desired properties will occur to those skilled in the art. Also, the disc may be of metal, such as aluminum, in which case it would be interiorly coated with a suitable resin material capable of preventing product interaction with the metal. I

It is also desirable that disc 20 be relatively stiff, for reasons now to be explained. Referring to FIG. 6, there is shown a preferred method and means for uniting the headpiece 15 with its associated barrier disc 20 to the tube body 10. The body is first telescoped onto a male tool 40 which is shaped at its upper end with a shoulder portion 41 and a neck portion 42. Between the shoulder portion 41 and the cylindrical wall of the mandrel is an undercut or stepped surface 43 which forms an annular relief between the wall and shoulder surfaces of the mandrel.

Insert disc 20 is placed on theupper end of the mandrel, either before or after body 10, with the breast portion 22 and annular portion 21 of the disc snuggly embracing the shoulder and neck portions of the mandrel, respectively. Annular surface 43 is appropriately dimensioned so that peripheral edge 23 of the insert disc projects substantially over the annular relief provided by the surface 43.

The mandrel 40, with body 10 and disc 20 carried thereon, is now placed in a segmented female mold 44 having corresponding wall, shoulder and neck surfaces which define with the mandrel surfaces a headpiece mold cavity 45. The juncture between the wall and shoulder surfaces of the female mold is curved to cause the upper end of tube body 10 to turn in slightly over the cavity 45, in the manner taught in U.S. Pat. No. 2,713,369. The assembled mold now receives a charge of molten thermoplastic material from an external pressurized source (now shown), which thermoplastic material completely fills the headpiece cavity and fuses to the inner layer 13 of body 10 about the circumference of peripheral band portion 18 which extends from the curved-in end of the body downwardly between the peripheral edge 23 of the insert disc and inner surface of body 10. The molten material fills in between the spaced projections 24-25 on the annular surface of the disc 20.

it will be noted also that the molten material flows around and under the edge 23 of disc 20, forming in the relief 43 the annular lip portion 19 of the headpiece. This lip assists the spaced projections on the upper surface of the disc in firmly securing the disc to the headpiece. It is because of the formation of the lip portion 19 that disc 20, at least in the region of its peripheral edge 23, should be relatively stiff or rigid. Otherwise, the pressure of the molten material acting against the upper surface of the projecting edge 23 could cause this edge to buckle or collapse against the underlying surface 43.

Referring now to Fig. 5, there is shown a modification of my invention in which the headpiece barrier member, designated by numeral 30, includes a threaded neck portion 31 which acts as the screw cap receiving element. In other words, in this embodiment the thermoplastic headpiece includes only a breast portion 28 which terminates in a shortened annular portion 29 surrounding the base of neck portion 31 on the insert member. The insert member includes the conical portion 32, which may have spaced projections 36--37 on its upper surface as in the preceding embodiment, which spaced projections imbed in the underside of headpiece breast portion 28. The lower peripheral wall of the neck portion 31 is provided with spaced projections 3435, similar to the

elements

24 and 25 in the preceding embodiment, which imbed in the inner surface of portion 29 of the headpiece breast. The barrier member 30 may also include a thin wall 38 extending transversely across the base of the hollow neck 31, which thin wall includes a flapper valve 39 formed by partially slitting the thin wall 38. This provides a flexible flap portion in the wall 38 which flexes outwardly as shown in dotted lines in FIG. 5, to permit egress of the product when the container is squeezed. This flap portion returns to a closed position when the squeezing pressure on the tube body is relaxed. This valve 39 minimizes the suckback of air into the interior of the tube due to the tendency of the walls of the tube body to return to their uncollapsed position.

It will be understood that the selection of the means for anchoring the headpiece and barrier member together in the several embodiments of this invention will depend in part on the materials selected for each component and the manufacturing procedures involved. For example, if the two components are of dissimilar material (eg polyethylene for the headpiece and urea formaldehyde for the barrier member) which are incapable of thermally fusing together under the temperature and pressure conditions selected for the manufacturing operation, anchoring the components together depends entirely on the spaced projections on the barrier member and/or the underlying lip 19 which secures the edge 23. On the other hand, it is contemplated that for some applications, materials may be selected for the insert member and headpiece which are capable of thermal fusion at the interface of these two components, in which case the spaced projections on the barrier member may be fewer in number of less coarse than is illustrated in the drawings.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

lclaim:

1. A collapsible dispensing container comprising a deformable body having low permeability, a thennoplastic headpiece including a peripheral band portion united to an end of said body, and a barrier member of impenneable material fixed to the inner surface of said headpiece and having a peripheral edge disposed within and spaced from the inner wall of said tube end, said headpiece band portion including an annular lip underlying said peripheral edge of said barrier member.

2. The container of claim 1 wherein said barrier member includes a hollow neck extending centrally through said headpiece for receiving a closure element I 3. The container of claim 1 wherein said barrier member includes a central apertured portion with valve means for limiting air being drawn into the interior of the container.

4. A collapsible dispensing container, comprising a deformable body having low permeability, a thermoplastic headpiece, united along a peripheral band portion to an end of said body, and a barrier member of impermeable material fused to the inside surface of said headpiece, said barrier member including spaced rings and ribs projecting from the upper surface of said barrier member, embedded in said headpiece for anchoring the two together.

5. In a collapsible dispensing tube which includes a deformable body having low permeability and a thermoplastic headpiece united along a peripheral band portion to an end of the body, the improvement which comprises a low permeability, barrier member located adjacent to the inside surface of the headpiece; and a plurality of spaced, radial ribs projecting from a surface of the barrier member, embedded in the headpiece, for anchoring the barrier member to the headpiece.

6. A collapsible dispensing container, comprising:

a deformable body having low permeability;

a thermoplastic headpiece united along a peripheral band portion to an end of said body;

a barrier member of low permeability, secured to the inside surface of said headpiece;

a portion of the surface of said barrier member being located adjacent to the inside surface of said headpiece and including a plurality of spaced projections embedded in said headpiece;

said plurality of spaced projections, as viewed in a cross-sectional view taken normal to said surface portion of said barrier member, including an inner projection, an outer projection and an intermediate projection separated from said inner and outer projections by a region of said barrier member having a reduced cross section thickness; and

said inner projection being more remote from said deformable body than said outer and intermediate projections; and said intermediate projections being located between said inner and outer projections on said surface portion of said barrier member.

7. A container, as defined in claim 6, wherein said spaced projections take the form of annular rings.

8. A container, as defined in claim 6, wherein said barrier member is made of a material, the melting point of which is substantially higher than the headpiece, and said plurality of projections, embedded in said headpiece, anchor the barrier member to said headpiece.

9. A container, as defined in claim 8, wherein said spaced projections take the form of annular rings.

10. A container, as defined in claim 8, wherein said barrier member is a molded member made from a thermosetting material.

11. A container, as defined in claim 10, wherein said thermosetting material is urea formaldehyde.

Claims

1. A collapsible dispensing container comprising a deformable body having low permeability, a thermoplastic headpiece including a peripheral band portion united to an end of said body, and a barrier member of impermeable material fixed to the inner surface of said headpiece and having a peripheral edge disposed within and spaced from the inner wall of said tube end, said headpiece band portion including an annular lip underlying said peripheral edge of said barrier member.

2. The container of claim 1 wherein said barrier member includes a hollow neck extending centrally through said headpiece for receiving a closure element.

3. The container of claim 1 wherein said barrier member includes a central apertured portion with valve means for limiting air being drawn into the interior of the container.

6. A collapsible dispensing container, comprising: a deformable body having low permeability; a thermoplastic headpiece united along a peripheral band portion to an end of said body; a barrier member of low permeability, secured to the inside surface of said headpiece; a portion of the surface of said barrier member being located adjacent to the inside surface of said headpiece and including a plurality of spaced projections embedded in said headpiece; said plurality of spaced projections, as viewed in a cross-sectional view taken normal to said surface portion of said barrier member, including an inner projection, an outer projection and an intermediate projection separated from said inner and outer projections by a region of said barrier member having a reduced cross section thickness; and said inner projection being more remote from said deformable body than said outer and intermediate projections; and said intermediate projections being located between said inner and outer projections on said surface portion of said barrier member.