GB2050236A

GB2050236A - Collapsible tube container and method for making the same

Info

Publication number: GB2050236A
Application number: GB8007453A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-03-19
Filing date: 1980-03-05
Publication date: 1981-01-07
Also published as: IT8067408A0; GB2050236B; FR2451867A1; JPS55124633A; FR2451867B1; CH645586A5; DE3010570A1; IT1128047B

Abstract

A collapsible tube container comprising a tube (1) whose outer surface is made of metallic sheet, a neck formed integral with the tube, and a cap of thermoplastic synthetic resin molded directly around the neck of the tube to seal the neck completely. The collapsible tube container is made by inserting a core (A) into the tube to close from inside an opening of the neck of the tube, combining a female half (B) of a die with the neck of the tube and core to form a cavity therebetween, introducing molten synthetic resin (5) into the cavity, hardening molten synthetic resin therein to form a cap, and then removing the die (B) and core (A) to thereby make a collapsible tube container having the cap sealingly and integrally molded around the neck of the tube. <IMAGE>

Description

SPECIFICATION Collapsible tube container and method for making the same The present invention relates to a new collapsible tube container and method for making the same. More particularly, the present in ventidn relates to a collapsible tube container whose neck is sealed by a cap made of thermoplastic synthetic resin and making it possible to keep the collapsible tube container completely sealed until the consumer removes the cap from the tube for the first time after the tube is filled with contents, and to a method for making the tube efficiently.

As well known, in the case of the collapsible tube in which contents such as food, drug, tooth-paste and paint are to be contained, a cap made of synthetic resin is fitted or screwed onto the engaging projection or thread formed around the neck of the tube.

However, tubes and caps are made individually and thereafter fitted or screwed one another, so that they tend to be too tightly or loosely applied because of errors caused in the manufacturing process thereof. In addition, cases occur in which the caps are incorrectly fitted e.g. applied with crossed threads and so on. These are problems which frequently occur in automated capping processes, and as a result it is necessary to re-cap faulty tubes before these wrongly capped tubes are filled with contents through the opening formed at the back end of each of the tubes. This re-capping operation is also necessary against vibration added to capped tubes during transportation to a relatively remote factory, and shrinkage and deformation of synthetic resin of which caps are made during periods during which the capped tubes are stocked prior to use.Further, though depending on contents to be contained, tubes may be more completely sealed by inserting a packing inside each of caps or sealing the opening of the neck of each of tubes by a blind cap. If not, contents will tend to leak out of capped tubes through gaps inevitably formed between the inner face of the cap and outer face of the neck.

According to the present invention there is provided a collapsible tube container comprising a tube whose outer surface is made of metallic sheet, a neck formed integral with the tube, and a cap of thermoplastic synthetic resin molded directly around the neck wherein the cap is molded directly around the neck in a manner of the neck being inserted into the cap to seal the tube, and manually removed from the neck on use.

The invention also includes a method for manufacturing a collapsible tube in accordance with the present invention which method comprises inserting a core plate into a tube whose outer surface is made of metallic sheet and having a neck formed integral therewith to reinforce from inside the tube and to close an opening of the neck, combining the neck of the tube into which the core plate has been inserted and which functions as a male half of a die with a female half of the die to form a cavity, hardening and fixing thermoplastic synthetic resin in the cavity to form a cap, and then removing the male half or neck of the tube and the core plate from the female half and the tube, respectively, to thereby make a tube container having the cap sealingly molded around the neck of the tube.

The present invention therefore provides a collapsible tube container on the neck of which is directly molded thermoplastic synthetic resin to form a cap around the neck for the purpose of completely sealing the tube and a method for making the tube comprising directly molding the cap around the neck of the tube using the neck portion as a male half of a die and arranging a female half opposite the male half.

In this way, by moulding the cap around the neck of the tube not to form any gap between the inner surface of the cap and outer surface of the neck, leaking is substantially prevented and the tube is completely sealed.

The invention thus makes it unnecessary to form a blind cap integral with the neck of the tube for the purpose of sealing the tube. In one aspect of the invention the insertion of a wad or similar packing is also unnecessary.

Following is a description by way of example only and with reference to the accompanying drawings of methods of carrying the invention into effect.

In the drawings: Figure 1 is a front view, partly broken, showing a tube of the present invention, Figures 2, 3 and 4 are front views showing other examples of the tube of the present invention, Figure 5 is a sectional front view of the tube positioned in a first stage of a tube making process with a core plate inserted thereinto, Figure 6 is a sectional front view of the tube positioned in a second stage of the tube making process with a female half of a die arranged and showing the state under which synthetic resin is about to be injected, Figure 7 is a sectional front view of the tube positioned in a third stage of the tube making process showing the state under which synthetic resin is injected, Figure 8 is a sectional front view of the tube removed with the core plate from the female half shown in Fig. 7, Figure 9 is a sectional front view showing a first stage of another tube making process of the present invention, Figure 10 is a sectional front view showing a second stage of the tube making process shown in Fig. 9, and Figure I 11 is a sectional front view showing a stage of a further tube making process of the present invention.

As shown in Fig. 1, a tube container 1 of the present invention comprises a neck 3 projecting forward from the shoulder 2 of a tube 1' in tapered fashion and integral with the tube 1', said tube 1' being a semiproduct whose lower end is usually opened, an engaging projection 4 formed around the outer circumference of the neck 3, and a cap 5 of thermoplastic synthetic resin molded onto the neck 3 using this neck as a male half of a die as will be later described. The tube 1' comprises a thin metallic sheet of aluminum, lead, tin or the like, or laminating these kinds of metallic sheets, or laminating some kinds of synthetic resins as thin layers on the inner surface of these laminated metallic sheets.

Reference numeral 3a represents an opening and 5a a portion on which fingers are put to remove the cap 5 from the tube 1'.

The engaging projection 4 may be a thread 14 formed around the outer circumference of the neck 3 as shown in Fig. 2, a ring-shaped projection 24 shown in Fig. 3, or a portion 34 formed by radially enlarging the foremost end of the neck 3 as shown in Fig. 4. As shown in Figs. 1, 3 and 4, the cap 5 molded around the neck 3 of the tube 1' may have its lower end contacted with the shoulder 2 of the tube 1', or separated from the shoulder 2 of the tube 1' (as shown in Fig. 2). In addition, the cap 5 may be formed to have a polygonal profile or 5a' a portion by which fingers are firmly held to remove the cap 5 from the tube 1' (as shown in Figs. 3 and 4).

A process for making the tube container 1 comprises inserting a core plate A into the tube 1' through an opening formed at the lower end of the tube 1' to reinforce from inside the shoulder 2 and neck 3 of the tube 1' as well as to close the opening 3a of the neck 3 as shown in Figs. 5 and 6, combining the neck 3 of the tube 1', into which the core plate A has been inserted, with a female half B of a die using the neck 3 of the tube 1' as a male half A' of the die to form therebetween a cavity C in which the cap 5 is molded, injecting molten thermoplastic synthetic resin P (which will be hereinafter referred to as molten resin) into the cavity C as shown in Fig. 7, cooling and hardening molten resin P in the cavity C to form the cap 5, and then removing the tube 1' and the core plate A from the female half or cavity plate B and the tube 1', respectively, to form the tube container 1 having the cap 5 closely fitted thereon, as shown in Fig. 8.

Another making process shown in Fig. 9 comprises applying from above a suitable amount of molten resin P into the cavity plate B, arranging from above the neck 3 of the tube 1', which functions as a male half A' and into which the core plate A has been inserted, into the female half or cavity plate B as shown in Fig. '10 to form the cavity C therebetween and at the same time compress, harden and fix molten resin P in the cavity C so as to directly mold the cap 5 around the neck 3 of the tube 1', separating the neck 3 or male half A' from the female half or cavity plate B, and then removing the core plate A from the tube 1' to thereby form the tube container 1 whose neck 3 is completely sealed by the cap 5.

In the case of the cap 5 having its lower end contacted with the shoulder 2 of the tube 1' as shown, for example, in Fig. 1, the female half or cavity plate B may be a single member, but in the case of the cap 5 having its lower end separated from the shoulder 2 of the tube 1' as shown, for example, in Fig. 2, or having a portion 5a' formed thereon as shown, for example, in Figs. 3 and 4 by which fingers are firmly held to remove the cap 5 from the neck 3 of the tube 1', the female half or cavity plate B must be divided as shown in Fig. 11. In the Figures symbol (a) represents a hollow portion of the core plate A and (b) passages through which air is allowed to pass.

According to the processes for making the tube container 1 of the present invention, the female half or cavity plate B is combined with the neck 3 of the tube 1', which functions as the male half A', to form the cavity C, molten resin P is hardened and fixed in the cavity C to form the cap 5, and the male half A' of the neck 3 is then separated from the female half or cavity plate B. Therefore, the cap 5 is molded with the male half A' of the neck 3 inserted thereinto and separated from the female half or cavity plate B under the state of being closely contacted with the outer face of the male half A' of the neck 3. In addition, the cap 5 is molded directly on the neck 3 of the tube 1', thus making it unnecessary to eject the cap 5 from the die by means of an ejector pin (not shown).Furthermore, the cap 5 removed outside from the female half or cavity plate B shrinks due to natural cooling to thereby more closely contact with the neck 3 to seal the tube 1' completely.

Since the tube 1' and the neck 3 integral with the tube 1' are made of metal having a melting point higher than that of molten resin P or by forming such metal as the surface of the tube 1' with synthetic resin laminated on the inner face of the tube metal, the neck 3 is not melted even if molten resin P contacts the neck 3 directly. In addition, even if the cap 5 is molded using the neck 3 of the tube 1' as the male half A' of the die, molten resin P is not allowed to enter into the tube 1' through the neck 3 thereof because the opening 3a of the neck 3 is closed by the core plate A.

Moreover, the tube 1' is not deformed at the time of the injection of molten resin P into the cavity C because the core plate A is inserted into the tube 1' to reinforce the neck 3 thereof.

When the consumer wants to remove the cap 5 from the neck 3 of the tube container 1, he may screw off the cap 5 from the neck 3 along the thread 14 thereof or pull off the cap 5 from the ring-shaped projection 24 formed on the neck 3 or from the radially enlarged portion 34 of the neck 3, thus releasing the sealing state between the cap 5 and the neck 3 to thereby make the cap 5 easily detachable thereafter.

Claims

1. A collapsible tube container comprising a tube whose outer surface is made of metallic sheet, a neck formed integral with the tube, and a cap of thermoplastic synthetic resin molded directly around the neck wherein the cap is molded directly around the neck in a manner of the neck being inserted into the cap to seal the tube, and manually removed from the neck on use.

2. A collapsible tube container according to Claim 1 wherein the neck has engaging portions formed thereon.

3. A collapsible tube as claimed in Claim 1 and substantially as herein described with reference to the accompanying drawings.

4. A method for making the collapsible tube container claimed in any preceding claim which method comprises inserting a core plate into a tube whose outer surface is made of metallic sheet and having a neck formed integral therewith to reinforce from inside the tube and to close an opening of the neck, combining the neck of the tube into which the core plate has been inserted and which functions as a male half of a die with a female half of the die to form a cavity, hardening and fixing thermoplastic synthetic resin in the cavity to form a cap, and then removing the male half or neck of the tube and the core plate from the female half and the tube, respectively, to thereby make a tube container having the cap sealingly molded around the neck of the tube.

5. A method for making the collapsible tube container as claimed in Claim 4 wherein the core plate is made of metallic sheet and has a neck formed integral therewith to reinforce from inside the tube and to close an opening of the neck, said female half of the die is disposed in juxtaposition to the neck of the tube into which the core plate has been inserted and which latter functions as a male half of the die to form a cavity, injecting theremoplastic synthetic resin into said cavity, hardening and fixing thermoplastic synthetic resin in the cavity to form a cap, and then removing the male half or neck of the tube and the core plate from the female half and the tube, respectively, to form a tube container having the cap sealingly and integrally molded around the neck of the tube.

6. A method as claimed in Claim 4 or Claim 5 which comprises applying molten resin in a female half of a die, combining the female half with a neck of a tube into which a core plate has been inserted and which functions as a male half of the die to form a cavity between the female half and the male half or neck of the tube and at the same time compress molten resin in the cavity, and then hardening and fixing molten resin to form a cap sealingly and integrally molded around the neck of the tube.

7. A method of sealing a collapsible tube as claimed in Claim 4 and substantially as herein described with reference to the accompanying drawings.