EP0859723A1

EP0859723A1 - Process for making a plastic container with a neck

Info

Publication number: EP0859723A1
Application number: EP96938159A
Authority: EP
Inventors: Roberto Tabaroni; Andrea Bartoli; Flavio Traldi
Original assignee: Unifill International AG
Current assignee: Unifill International AG
Priority date: 1995-11-07
Filing date: 1996-11-07
Publication date: 1998-08-26
Also published as: ITMO950153A1; IT1279877B1; WO1997017268A1; CN1201430A; MX9803586A; ITMO950153A0; BR9611314A; AU7568596A; CA2236026A1; JPH11514616A

Abstract

The method of producing a container comprises introducing between parts (1) of sheet material in a peripheral zone of said parts an insert (4) comprised of a tubular wall (7) intended to define an outlet from an interior of a container body to be provided by said parts (1), and sealing said parts (1) and said insert (4) to each other in said peripheral zone, wherein said introducing is preceded by forming said parts (1) as respective shells (1); the container comprises a body (1) having an outlet (3), said container being comprised of first and second semi-rigid shells (1) which provide the body (1) and are sealed together around their peripheries, and an insert (4) which is located and sealed between said shells (1) and which comprises a tubular wall (7) defining said outlet (3) and having a detent (10) extending therearound, at least one of said shells (1) including a corrugation (11) extending around said tubular wall (7) and engaging said detent (10).

Description

PROCESS FOR MAKING A PLASTIC CONTAINER WITH A NECK

Prior art comprises containers having a body equipped with a neck with coupling means for mounting a cap, so that the user may re-close the container after use.

Such containers are described, for example, in FR-A- 1.256.962, CH-A-495.888, BE-A-556.274.

In containers thermoformed pneumatically by plastics sheets heat-welded along their edge and having relatively large format, of for example about one litre, it is difficult to achieve a threaded portion on the neck due to the considerable stress that has to be exerted on the material to deform it.

FR-A-2.045.375 discloses a funnel for a sachet having a pair of diametrically opposed outwardly projecting wings providing side abutments for edge portions of opposing flexible walls of the sachet, the wings also supplying additional welding material during the heat-sealing of the edge portions. However, a difficulty arises in positioning the funnel with respect to a longitudinal axis of the container before the wings are sealed to the respective edge portions of the flexible walls.

The problem solved by the present invention is to improve existing containers made from opposing shells joined together around a peripheral seal, and/or their manufacture. According to a first aspect of the present invention, there is provided a method of producing a container, comprising introducing to between parts of sheet material in a peripheral zone of said parts an insert comprised of a tubular wall intended to define an outlet from an interior of a container body to be provided by said parts, and sealing said parts and said insert to each other in said peripheral zone, characterized in that said introducing is preceded by forming said parts as respective shells. According to a further aspect of the present invention. there is provided a container comprising a body the interior of which communicates with an outlet for discharging contents of said container, said container being comprised of first and second semi-rigid shells which provide the body and are sealed together around their peripheries, and an insert which is located and sealed between said shells and which comprises a tubular wall defining said outlet and having a detent extending therearound, characterized in that at least one of said shells includes a corrugation extending around said tubular wall and engaging said detent. According to a further aspect of the present invention, there is provided a container comprising a body the interior of which communicates with an outlet for discharging contents of said container, said container being comprised of first and second semi-rigid shells which provide the body and are sea-led together around their peripheries, and an insert which is located and sealed between said shells and which comprises a tubular wall defining said outlet and at least one wing projecting laterally outwards from said tubular wall, characterized in that the or each winςr is the form of a comb with teeth pointing outwardly and is sealed between said shells.

According to a further aspect of the present invention, there is provided an insert comprising a tubular wall and at least one wing laterally projecting from said tubular wall, characterized in that the or each wing is the form o:: a comb with teeth pointing outwardly.

According to a further aspect of the present invention, there is provided a container pre-form comprising first and second semi-rigid shells which provide a body for the container and which are sealed together around no more than a major part of their peripheries, characterized in that those respective portions of said shells which are not sealed at the peripheries include respective diametrically opposite troughs at least one of which is formed at its inside surface with a detent. Owing to the invention, it is possible to improve the conventional thermoformed containers, and/or their manufacture.

Owing to the provision of the at least one wing, particularly when in combination with a detent of the insert matching with corresponding corrugations of the two shells, a safe sealing of the container is achieved.

The invention will be better understood with reference to the attached drawings, in which:

Figure 1 is a perspective view of the upper part of a container with a screw cap unscrewed;

Figure 2 is a perspective view of an insert with a respective screw cap unscrewed;

Figure 3 is an interrupted perspective view of a container preform defined by a pair of shells blow thermoformed by respective sheets, the shells being only partially welded together along their peripheral edge;

Figure 4 is a side view of the insert shown in Figure 2; Figure 5 is a partially sectioned view from the right of Figure 4;

Figure 6 is an enlarged transverse section taken along line VI-VI of Figure 4;

Figure 7 is a longitudinal section of an insert equipped with an axially slideable snap cap and provided with opposing wings having the shape of a comb;

Figure 8 is a perspective view of a container preform sealed along its edge for receiving the comb-winged insert of Figure 7;

Figure 9 is a schematic side view of a blow thermoforming machine having an inserting station for positioning the insert into an opening of filled container pre-forms; Figure 10 is a schematic transverse section taken along line X-X of Figure 9.

A pair of shells 1, opposed and joined along their edges by means of a heat weld 2, defines the body of a container having a neck 3 with a tubular insert 4 protruding outwards and provided with, at its outer end, a thread 5 on which may be engaged by screwing a hollow cap 6, with internal thread. The insert 4 is made up of a tubular body 7 (Figure 2), defining, with an axial through hole 8 with which it is provided internally, the flow section for the product out of and into the container; from the external surface of the tubular body 7, in correspondence with a diametrically axial plane, project a pair of fins 9, or wings, that are held between corresponding peripheral zones 2a of the heat seal 2 of the neck 3.

The tubular body 7 is provided with a peripheral external groove 10, in which the material of the shells 1 forming the base of the neck 3, or an intermediate portion of it, is forced to adhere. The provision of the groove prevents the insert from moving in linear directions along a longitudinal axis of the neck.

With reference to Figure 3, the weld 2, which is obtained as a result of a blow thermoforming process, is interrupted at a transverse line A substantially corresponding to the inner end, or base, of the neck 3 in such a way that the shells themselves define a pair of flaps la adjacent to each other between which the insert 4 may be introduced with the fins 9 positioned between the flaps.

The portion of each flap that has to engage in the groove 10 is provided with an inwardly projecting annular projection 11 for the axial positioning of the insert, and intended subsequently to co-operate with the groove 10 to provide a more reliable and safe seal when the heat weld has been extended to the portions 2a.

As shown in Figure 4, at the base of the threaded portion 5 there is an external annular projection 12 on the insert 4 that may constitute a limit stop when screwing on the cap 6. As shown in Figure 7, the insert 4 may be provided, at one of its ends, with a pair of comb-shaped opposing wings 9a, each formed by relatively thin and flexible teeth 13. The other end of the insert 4 is provided with a slidable cap 14 movable between a closing position (shown in Figure 7) in which it closes a passage 15 for the product, and a open position, in which the product can be exited from the container by sqeezing via a hole 16 and the passage 15. The movement of the cap 14 between the open position and the closing position is operated manually, the cap being provided with guide means, i.e. internally projecting appendexes 17 engaged by axially extending grooves of the insert 4.

As shown in Figure 8, a container preform intended to receive the insert 4 of Figure 7, and particularly the comb- shaped wings 9a, is blown thermoformed so as to provide opposing shells which are peripherally sealed at their outline along a heat-seal 2, extended so as to define also a neck 3 of the container. The insert 4 is introduced by axially pushing it into an opening 19 of the neck 3; therefore-the flexible teeth 13 are bent upwardly so as to completely fill any gaps between the shells and the insert. As shown in Figure 9, a blow thermoforming machine having, in sequence, forming stations 20 at which at least one sheet of thermoformable material is thermoformed so as to obtain opposing shells therefrom defining containers pre-forms 21, at least one filling station 22 at which the container pre¬ form 21 are filled with a fluid product, may be provided with inserting means 23 for positioning the inserts 4 into respective neck portions 3 of containers pre-forms 21 already filled with product.

After the positioning of the inserts 4, sealing means are provided to seal the insert into the neck.

If the insert 4 is equipped with a screw end 5, the inserting means 23, providing the positioning of the tubular body 7, may be located before the filling station 22 into container pre-forms 21 not filled with product and screwing means (not shown) may be located after the filling station 22 for screwing the cap 6 on the threaded portion 5 of the insert 4. As shown in Figure 10, the inserting means 23 comprises clamp means 24 (shown in an open position) suitable for holding one insert 4 above a corresponding top opening of a container pre-form 21, said clamp means 24 being movable in a vertical direction along an axis Z for inserting the insert 4 in said top opening, releasing the insert into the opening and going back to its original position for clamping the next insert.

The container pre-form 21 is kept in a predetermined location with the opening aligned with the vertical, axis Z by centering means 25 comprising a pair of sucker means 25 movable in a direction substantially perpendicular to the axis Z.

The container preform 21 may be have non-welded flaps la, as shown in Figure 2, so that the sucker means 25 may act on opposing flaps la of the container preform in order to divaricate them to an extent suitable for allowing the detent 10 of the insert 4 to engage with the corresponding corrugation 11 of the shells.

When an insert 4 with comb-shaped wings 9a is used, the centering means 25 clamps the neck of the container preform so as to achieve alignment with the axis Z, but no divarication of the shells forming the container is required.

Inserts 4 are stores in tubular storing means 26, to which the inserts are fed by feeding means not shown, so that a pile of inserts 4 is obtained in said tubular storing means ending at an open lower end thereof, where the lower insert 4 rests on trasferring means 27 for transferring that insert from a neutral position in alignment with the open end of said tubular means to an operative position on the axis Z where the clamp means 24 may hold the insert before inserting it into the opening 19 of the container pre-form.

Claims

1. A method of producing a container, comprising introducing to between parts (1) of sheet material in a peripheral zone of said parts an insert (4) comprised of a tubular wall (7) intended to define an outlet from an interior of a container body to be provided by said parts (1), and sealing said parts (1) and said insert (4) to each other in said peripheral zone, characterized in that said introducing is preceded by forming said parts (1) as respective shells (1) .

2. A method as claimed in claim 1, wherein thermoplastic sheet material of a thickness of at least 150 microns is thermoformed to form said shells (1) .

3. A method as claimed in claim 1 or 2, wherein, prior to said introducing, said shells (1) are in a condition sealed together around no more than a major part of their peripheries and not sealed together at their peripheries in said peripheral zone.

4. A method as claimed in claim 1, or 2, wherein, prior to said introducing, said shells (1) are in a condition sealed together around no more than a major part of their peripheries including said peripheral zone.

5. A method as claimed in any one of claims 1 to 3, wherein said shells (1) are resilient in said peripheral zone and said method further comprises opening said shells (1) away from each other at said peripheral zone prior to said introducing, and releasing said shells (1) at said peripheral zone after said introducing to allow elastic return of said shells (1) at said peripheral zone.

6. A method as clamed in any preceding claim and further comprising, after said introducing and before said sealing, engaging with each other respective detents !10, 11) provided on said insert (4) and at least one of said shells

(1) •

7. A method as claimed in claim 6 as appended to claim 2, wherein the detent (11) in the or each shell (1) is thermoformed in the thermoforming of the shell (1) .

8. A method as claimed in claim 6 or 7, wherein, between said introducing and said sealing, said detents (10, 11) restrain said insert (4) against movement relative to said shells (1) in substantially all linear directions.

9. A method as claimed in any preceding claim, wherein, between said- introducing and said sealing, at least one wing

(9) projecting laterally from said tubular wall (7) restrains said insert (4) against turning relative to said shells (1).

10. A method as claimed in claim 1 or 2, wherein said insert (4) includes at least one comb-form wing (9) projecting laterally from said tubular wall (7) and. wherein said introducing comprises forcing said insert (4) to between said shells (1) at said peripheral zone to cause comb teeth (13) of the or each wing (9) to bear against a junction between said shells (1) at said peripheral zone to bend said teeth (13) backwards.

11. A method as claimed in claim 2 or 8, or any one of claims 3 to 6 or 8 to 10 as appended to claim 2, wherein said insert (4) is of thermoplastics and, prior to said introducing, said junction and said wing (9) are heated to soften the thermoplastics of the same.

12. A container comprising a body (1) the interior of which communicates with an outlet (3) for discharging contents of said container, said container being comprised of first and second semi-rigid shells (1) which provide the body (1) and are sealed together around their peripheries, and an insert (4) which is located and sealed between said shells (1) and which comprises a tubular wall (7) defining said outlet (3) and having a detent (10) extending therearound, characterized in that at least one of said shells (1) includes a corrugation (11) extending around said tubular wall (7) and engaging said detent (10) .

13. A container as claimed in claim 12, wherein each shell (1) has been formed from thermoplastic sheet material of a thickness of at least 150 microns.

14. A container as claimed in claim 12 or 13, wherein said insert (4) includes at least one wing (9) projecting laterally outwards from said tubular wall (7) and in the form of a comb (9a) with teeth (13) pointing outwardly, the or each wing (9) being sealed between said shells (1) .

15. A container comprising a body (1) the interior of which communicates with an outlet (3) for discharging contents of said container, said container being comprised of first and second semi-rigid shells (1) which provide the body (1) and are sealed together around their peripheries, and an insert (4) which is located and sealed between said shells (1) and which comprises a tubular wall (7) defining said outlet (3) and at least one wing (9) projecting laterally outwards from said tubular wall (7) , characterized in that the or each wing (9) is the form of a comb (9a) with teeth (13) pointing outwardly and is sealed between said shells (1) .

16. An insert comprising a tubular wall (7) and at least one wing (9) laterally projecting from said tubular wall (7), characterized in that the or each wing (9) is the form of a comb (9a) with teeth (13) pointing outwardly.

17. A container pre-form comprising first and second semi¬ rigid shells (1) which provide a body (1) for the container and which are sealed together around no more than a major part of their peripheries, characterized in that those respective portions (la) of said shells (1) which are not sealed at the peripheries include respective diametrically opposite troughs at least one of which is formed at its inside surface with a detent (11) .

18. A container pre-form as claimed in claim 17, wherein the or each detent (11) is provided by a corrugation (11) extending around its trough.