Head for a tube with a flexible skirt and tube therewith

Abstract

The invention relates to a head (14) for a tube (10) comprising a flexible skirt (12), the head (14) comprising: - an annular shoulder (20) extending from the central portion (16) in a substantially radial direction, - an internal annular exposed portion (22) of the shoulder (20) intended to be visible after assembly of the head (14) with the flexible skirt (12); - an annular peripheral bearing face (26) of the shoulder (20) against which a section (12A) of the upper end of the flexible skirt (12) is intended to be folded down to allow its welding; - an annular shoulder face (28) projecting relative to the peripheral bearing face (26); characterized in that the annular shoulder face (28) has, in axial section, an opening angle (β) greater than 125° relative to the peripheral bearing face (26).

Description

Technical field of the invention

[0001] The present invention relates to a head for a tube comprising a flexible skirt, the head having a main axis and comprising: a central portion equipped with a distribution orifice, an annular shoulder extending from the central portion in a substantially radial direction, an internal annular exposed portion of the shoulder intended to be visible after assembly of the head with the flexible skirt; an annular peripheral bearing face of the shoulder against which an upper end section of the flexible skirt is intended to be folded down to allow its welding; an annular shoulder face projecting from the peripheral bearing face and facing radially outwards which delimits the peripheral bearing face and the exposed portion. Technical background

[0002] Such tubes are specifically designed to contain pastes, ointments, or creams. These include, for example, cosmetic or personal care products.

[0003] It is common practice to equip flexible tubing with a rigid tube head. The rigid head has a shoulder near the center of which is an orifice for dispensing the product inside the tube. Such a head improves the tube's usability by providing a better grip for the user and allowing for controlled dispensing of the product.

[0004] In the manufacture of such a flexible tube, it is common practice to produce a flexible tube skirt and a rigid head separately. The flexible skirt is made, for example, by winding and welding a laminated sheet or by extrusion.

[0005] The head is fitted into one end, called the upper end, of the skirt, then a section of the upper end of the skirt is folded down against a peripheral bearing face of the shoulder to be welded there.

[0006] The peripheral bearing face of the shoulder, for example, has the shape of a rebate delimited internally by an annular shoulder face facing outwards. The shoulder face is generally parallel to the axis of the tube.

[0007] The rebate has a height slightly greater than the wall thickness of the flexible skirt. During welding, the folded section of the flexible skirt is pressed against the peripheral bearing face and some of the material constituting it flows towards the shoulder face.

[0008] The height of the shoulder face is designed so that the material flowing towards the shoulder face does not create a weld bead that protrudes from the surface of the exposed portion of the shoulder. This is essential to give the weld an aesthetically pleasing appearance that conveys an image of product quality to the buyer.

[0009] This configuration requires designing a specific head for each skirt thickness, this thickness being able to vary for example between 0.14 mm and 0.3 mm depending on the tube design.

[0010] Therefore, there is a need to be able to adapt the same tube head to several thicknesses of flexible skirt while maintaining an aesthetic weld. Summary of the invention

[0011] The present invention proposes a head for a tube comprising a flexible skirt, the head comprising: a central portion equipped with a distribution orifice, an annular shoulder extending from the central portion in a substantially radial direction, an internal annular exposed portion of the shoulder intended to be visible after assembly of the head with the flexible skirt; an annular peripheral bearing face of the shoulder against which an upper end section of the flexible skirt is intended to be folded down to allow its welding; an annular shoulder face projecting from the peripheral bearing face and facing radially outwards which delimits the peripheral bearing face and the exposed portion; characterized in that the annular shoulder face has, in axial section, an opening angle greater than 125° relative to the peripheral bearing face.

[0012] According to another feature of the head according to the teachings of the invention, the annular shoulder face has, in axial section, an opening angle greater than 140° with respect to the peripheral bearing face.

[0013] According to another feature of the head according to the teachings of the invention, the annular shoulder face has, in axial section, an opening angle of less than 155° with respect to the peripheral bearing face.

[0014] According to another feature of the head according to the teachings of the invention, the annular shoulder face has, in axial section, an angle equal to 148° with respect to the peripheral bearing face.

[0015] According to another feature of the head according to the teachings of the invention, the peripheral bearing face extends, in axial section, parallel to at least one external peripheral part of the exposed portion of the shoulder.

[0016] According to another feature of the head according to the teachings of the invention, the bearing face is extended axially downwards by an axial sleeve which is intended to be fitted into the flexible skirt and which is linked to the bearing face by a rounded end.

[0017] The invention also proposes a flexible tube comprising a head made according to the teachings of the invention and a flexible skirt of which an upper end section is folded over the peripheral bearing face and welded against said peripheral bearing face.

[0018] According to another feature of the tube according to the teachings of the invention, the shoulder face has a height, taken orthogonally to the peripheral bearing face, which is greater than or equal to the nominal thickness of the flexible skirt wall before it is welded to the head.

[0019] According to another feature of the tube according to the teachings of the invention, the height of the shoulder face is between 0.40 mm and 0.70 mm.

[0020] According to another characteristic of the tube according to the teachings of the invention, the height is equal to 0.40 mm and the nominal wall thickness of the skirt before its welding to the head is between 200 µm and 400 µm.

[0021] According to another characteristic of the tube according to the teachings of the invention, the height is equal to 0.70 mm and the nominal wall thickness of the skirt before its welding to the head is between 200 µm and 500 µm. Brief description of the figures

[0022] Other features, purposes and advantages of the invention will become apparent from the following description, which is purely illustrative and not limiting, and which should be read in conjunction with the attached drawings briefly described below. There figure 1is a perspective view representing a tube comprising a head manufactured according to the teachings of the invention. figure 2 is a perspective view that represents the head of the tube of the figure 1 . There figure 3 is a half-axial view that represents the head of the figure 2 . There figure 4 is a view similar to that of the figure 2 in which the head was fitted into a flexible skirt for assembly. figure 5 is a view similar to that of the figure 4 in which a nozzle blows hot air between the end section of the skirt and a peripheral bearing face of the head. figure 6 is a view similar to that of the figure 4 in which an end section of the skirt has been folded back against a peripheral face of the head. The figure 7 is a view similar to that of the figure 5 in which the skirt was welded to the peripheral bearing face of the head. Detailed description of the invention

[0023] For the remainder of the description, elements with an identical structure or analogous functions will be designated by the same reference.

[0024] For the remainder of this description, we will adopt an axial direction that corresponds in the figures to that of the main axis "A" of the tube head. We will also adopt radial directions perpendicular to the axial direction, radiating from the main axis. Finally, we will adopt a circumferential direction perpendicular to the axial and radial directions.

[0025] The terms superior and inferior will be used, without limitation, in reference to the representation of the tube on the figure 1 in which the head is arranged at the top and the skirt is arranged at the bottom. These terms are used as a geometric reference unrelated to the direction of Earth's gravity.

[0026] We represented at the figure 1 a tube 10 intended to contain a liquid or paste product, in particular a cosmetic product or a personal care product.

[0027] The tube 10 has a body 11 made by a tubular skirt 12 of flexible and deformable material whose upper end is closed by a head 14. The tubular skirt 12 has a main axis "A".

[0028] The skirt 12 has a wall having at least one internal weld layer intended to be in contact with the tube head 14. The weld layer is, for example, made of a plastic material such as polypropylene (PP) or polyethylene (PE).

[0029] Skirt 12, for example, is made by rolling and welding the two adjoining edges, including overlapping, of a sheet of laminate.

[0030] Alternatively, skirt 12 is produced directly in its tubular configuration by extrusion.

[0031] The 14-tube head, most notably visible at figures 2 And 3 , presents a central main axis "A" which passes substantially through its center. The main axis "A" is coaxial with the axis of the tubular skirt 12.

[0032] The tube head 14 is made from a single piece of material. Preferably, the head 14 is made of a rigid plastic material, such as high-density polyethylene (HDPE) or polypropylene (PP). It is manufactured, for example, by injection molding in a mold.

[0033] The head 14 has a central portion 16 equipped with an orifice 18 for distributing the product contained in the tube 10. A user can discharge the contents of the tube 10 through the distribution orifice 18 by squeezing the body 11.

[0034] The central portion 16 here has the form of a tubular neck that projects axially upwards. The neck is arranged coaxially with the main axis "A". The neck is traversed axially by the distribution orifice 18.

[0035] Alternatively, the central portion 16 is an upper wall orthogonal to the main axis "A". The upper wall is traversed by the distribution orifice 18, which may be eccentric with respect to the main axis "A" or coaxial with the main axis "A".

[0036] The dispensing orifice 18 can be closed by a plug (not shown) and / or by a peelable or tearable cap. The plug can be made in one piece separate from the head 14 or in one piece formed from the same material as the head 14.

[0037] The head 14 further comprises an annular shoulder 20 which connects the central portion 16 of the head 14 to the tubular skirt 12. The annular shoulder 20 extends from the central portion 16 in a substantially radial direction with respect to the main axis.

[0038] The shoulder 20 has a first internal annular portion, called the exposed portion 22, which is intended to be visible after the assembly of the head 14 with the flexible skirt 12.

[0039] This exposed portion 22 generally has a truncated cone shape which extends downwards, widening from the central portion 16 of the head 14. The exposed portion 22 has, for example, but not limited to, in axial section, an angle γ between 25° and 35°, preferably 30°, with respect to a plane orthogonal to the main axis "A".

[0040] Alternatively, the exposed portion 22 may have, in axial section, a complex shape with rounded edges and / or stepped features. In this case, a periphery of the exposed portion 22 has, in axial section, a straight line having an angle between 25° and 35°, preferably 30°, with respect to a plane orthogonal to the main axis.

[0041] Alternatively, when the periphery of the exposed portion 22 has a fillet shape, the tangent has an angle between 25° and 35°, preferably 30°, with respect to a plane orthogonal to the main axis.

[0042] The shoulder 20 further includes a concealed portion 24 which is intended to be fitted inside the flexible skirt 12 as shown in the figure 4 The masked portion 24 is delimited below by a lower end edge 25 which extends in a plane orthogonal to the main axis "A".

[0043] The concealed portion 24 has a face 26 with an annular peripheral bearing surface. In axial section, the face 26 has a rectilinear shape. It is axially oriented upwards so as to form an angle with the axial direction in axial section. A section 12A at the upper end of the flexible skirt 12 is designed to be folded down to allow for welding.

[0044] The peripheral face 26, for example, has an axial section with an angle between 25° and 35°, preferably 30°, relative to a plane orthogonal to the main axis "A".

[0045] The peripheral face 26 extends here, in axial section, parallel to the exposed portion 22.

[0046] The peripheral face 26, for example, has an axial width "I" of at least 0.20 mm. The width "I" is, for example, between 0.40 mm and 0.60 mm, preferably between 0.50 mm and 0.55 mm, for example 0.52 mm.

[0047] The head 14 further comprises an annular shoulder face 28 projecting upwards from the peripheral bearing face 26. The shoulder face 28 is inclined so as to face radially outwards and upwards. It delimits the peripheral bearing face 26 from the exposed portion 22. More specifically, a lower edge 28A of the shoulder face 28 delimits the peripheral bearing face 26 internally.

[0048] The peripheral face 26 is stepped relative to the periphery of the exposed portion 22 of the shoulder 20. Thus, an upper edge 28B of the shoulder face 28 internally delimits the exposed portion 22. The peripheral face 26 and the shoulder face 28 thus form a rebate for receiving the folded-down end section 12A of the skirt 12.

[0049] As depicted in the figure 3The annular shoulder face 28 has, in axial section, an opening angle β greater than 125° relative to the peripheral bearing face 26. Preferably, said opening angle β is greater than 140°. Preferably, said opening angle β is less than 155°. Said opening angle β is, for example, equal to 148°.

[0050] The opening angle β is constant here all along the shoulder face 28.

[0051] This specific inclination of the shoulder face 28 makes it possible to create sufficient space to receive the material of the wall of the flexible skirt 12 which flows inwards when it is welded with the head 14, as will be explained in more detail later.

[0052] Furthermore, the concealed portion 24 of the head 14 includes an axial sleeve 30 that extends the peripheral bearing face 26 axially downwards. This sleeve 30 is designed to be fitted into the flexible skirt 12 to ensure that the head 14 is securely held within the skirt. The sleeve 30 is connected to the peripheral bearing face 26 by a rounded edge 32, which prevents the skirt 12 from forming creases when its end section 12A is folded back onto the peripheral bearing face 26. A lower end edge of the sleeve 30 forms the lower end edge 25 of the head 14, which extends in a plane orthogonal to the principal axis "A".

[0053] The shoulder face 28 has a height "h", measured orthogonally to the peripheral bearing face 26, which is greater than the nominal thickness "e" of the wall of the flexible skirt 12. The nominal thickness "e" of the skirt wall 12 is defined as its thickness "e" measured before welding it to the head 14. During welding, the wall is heated and pressed against the peripheral bearing face 26, which reduces its thickness "e". After welding, the folded section 12A of the skirt 12 has a thickness "e" less than or equal to, preferably less than, the height "h" of the shoulder face 28.

[0054] The height "h" of the shoulder face 28 is, for example, between 0.40 mm and 0.70 mm. Preferably, the shoulder face 28 has a height "h" of 0.40 mm.

[0055] The same head 14 is thus likely to be associated with skirts 12 having a thickness "e" less than or equal to, preferably less than, the height "h".

[0056] For example, the same head 14 having a face height 28 of shoulder 0.40 mm is likely to be assembled with skirts 12 having a thickness e between 200 µm and 400µm.

[0057] According to another embodiment, the same head 14 having a face height "h" 28 of shoulder of 0.70 mm is likely to be assembled with skirts 12 having a thickness "e" between 200 µm and 500µm.

[0058] During the manufacture of the tube 10, the head 14 produced according to the teachings of the invention is inserted into the skirt 12, previously shaped into a tube, as shown in the figure 4 .

[0059] As depicted in the figure 6A section 12A at the upper end of the skirt 12 is folded against the peripheral bearing face 26 so that the upper end edge 12B of the skirt 12 is substantially aligned with the lower edge 28A of the shoulder face 28. The bearing face 26 and the upper end section 12A of the skirt 12 have been preheated to allow for welding. Thus, during the welding operation, a free space 34 with a triangular shape in axial section is left between the shoulder face 28 and the end edge 12B of the skirt 12.

[0060] Then, as depicted in the figure 7 , at the end of welding, the skirt 12 is welded against the peripheral face 26.

[0061] During this operation, the section 12A of the skirt 12, folded against the peripheral bearing face 26, is pressed against the latter. Material 36 forming the skirt 12, made malleable by the heating during the welding operation, flows into the free space 34, which has sufficient volume to accommodate different quantities of flowing material 36 depending on the thickness "e" of the skirt wall 12. The flowing material 36 fills the free space 34 so as to be flush with the periphery of the exposed portion 22 of the shoulder 20. In this way, the folded and welded section 12A of the flexible skirt 12 extends radially in the direct continuation of the exposed portion 22 of the shoulder 20.

[0062] Preferably, the skirt 12 is welded against the peripheral bearing face 26 by thermal welding using an annular nozzle 33 which blows hot air "F" towards the bearing face 26 before the skirt section 12A has been folded down, as illustrated in the figure 5 The nozzle 33 is generally offset radially outwards and blows hot air simultaneously over the entire bearing surface 26. The hot air softens the material constituting the skirt in preparation for welding it to the bearing surface 26.

[0063] The angle β of inclination of the shoulder face 28 helps to promote the flow of hot air towards the span face 28.

[0064] The angle β of inclination of the shoulder face 28 also allows some freedom in orienting the nozzle, particularly when the head 14 is fitted with a hinged cap made in one piece with the head 14, a fairly wide "flip top." Indeed, the welding operation is generally performed with the cap closed. However, the cap has an opening tab that protrudes radially above the shoulder to allow the thumb to press against it to open the cap. The space left by the tab does not allow the nozzle to be positioned directly above the bearing face. The inclination of the bearing face thus allows the nozzle to be positioned slightly offset radially outwards.

[0065] Furthermore, the height "h" of the shoulder face 28 is significantly greater than on state-of-the-art nozzle heads. The angle β of inclination of the shoulder face 28 allows sufficient radial clearance for the nozzle even when the tube 10 has not been correctly centered relative to the nozzle.

Claims

1. Head (14) for a tube (10) having a flexible skirt (12), the head (14) having: - a central portion (16) equipped with a distribution orifice (18), - an annular shoulder (20) extending from the central portion (16) in a substantially radial direction, - an internal annular exposed portion (22) of the shoulder (20) intended to be visible after assembly of the head (14) with the flexible skirt (12); - an annular peripheral bearing face (26) of the shoulder (20) against which an upper end section (12A) of the flexible skirt (12) is intended to be folded down to allow its welding; - an annular shoulder face (28) projecting from the peripheral bearing face (26) and facing radially outwards which delimits the peripheral bearing face (26) and the exposed portion (22); characterized in thatthe face (28) of annular shoulder has, in axial section, an opening angle (β) greater than 125° with respect to the face (26) of peripheral bearing.

2. Head (14) according to the preceding claim, characterized in that the face (28) of annular shoulder has, in axial section, an opening angle (β) greater than 140° with respect to the face (26) of peripheral bearing.

3. Head (14) according to the preceding claim, characterized in that the face (28) of annular shoulder has, in axial section, an opening angle (β) of less than 155° with respect to the face (26) of peripheral bearing.

4. Head (14) according to the preceding claim, characterized in that the face (28) of annular shoulder has, in axial section, an angle (β) equal to 148° with respect to the face (26) of peripheral span.

5. Head (14) according to any one of the preceding claims, characterized in thatthe peripheral face (26) extends, in axial section, parallel to at least one external peripheral part of the exposed portion (22) of the shoulder.

6. Head (14) according to the preceding claim, characterized in that the bearing face (26) is extended axially downwards by an axial sleeve which is intended to be fitted into the flexible skirt (12) and which is linked to the bearing face (26) by a rounded end (32).

7. Flexible tube (10) comprising a head (14) according to any one of the preceding claims and a flexible skirt (12) of which an upper end section (12A) is folded over the peripheral bearing face (26) and welded against said peripheral bearing face (26).

8. Tube (10) according to the preceding claim, characterized in thatthe shoulder face (28) has a height (h), taken orthogonally to the peripheral bearing face (26), which is greater than or equal to the nominal thickness (e) of the wall of the flexible skirt (12) before it is welded to the head (14).

9. Tube (10) according to the preceding claim, characterized in that the height (h) of the shoulder face (28) is between 0.40 mm and 0.70 mm.

10. Tube (10) according to the preceding claim, characterized in that the height (h) is equal to 0.40 mm and the nominal wall thickness of the skirt (12) before its welding to the head (14) is between 200 µm and 400 µm.

11. Tube (10) according to claim 9, characterized in that the height (h) is equal to 0.70 mm and the nominal wall thickness of the skirt (12) before its welding to the head (14) is between 200 µm and 500 µm.

Images