EP0315554A1 - Tube to dispense striped paste, having a one-piece, double-walled head - Google Patents

Abstract

The invention relates to a tube for dispensing a paste with stripes, the head (1) of which is connected by molding to the skirt (4) of the tube comprises an inner skirt (8) integral with this head (1), this skirt ( 8) carrying passage openings (13,14) of the striped product, said skirt (8) carrying pairs of internal longitudinal guide ribs (17,18,22) of the striped product framing these openings (13,14) and extending to the top of the neck (7). According to the invention: a) the head (1) of the tube has a double skirt, its outer skirt (16) forming the outside of the neck (7), and its inner skirt (8) starting from the top (5) of the head (1) and forming the inside of the neck (7) and the outlet conduit (8) of the pasty product; b) said passage openings (13, 14, 15) are located at least in part above the fictitious extension of the slightly inclined back surface (10) of the shoulder (2); c) the internal skirt (8) carries longitudinal internal ribs (26,35) braking the main pasty product, these comprising ribs (26) running from each passage opening (14) to at least the lower third of the portion of said skirt (8) located under this opening (14).

Description

The invention relates to a flexible tube, comprising a skirt and a head, both at least partly made of plastic, for dispensing a paste with stripes.

STATE OF THE ART

Patent FR-B-2,572,366 (= patent application EP-AO 182,725) to the applicant describes such a tube, the head of which comprises a neck, which carries an outlet orifice and possibly a cover, and below this neck a shoulder by which the head is connected by molding to the skirt of the tube, the head further comprising an internal skirt of plastic material which is integral with the head, being molded in the same injection molding operation as this head. This inner skirt carries slots for the passage of the striped product, as well as often pairs of longitudinal ribs extending from the top of these passage slots to the top of the internal surface of the neck and guiding the colored product for its exit. in the form of a stripe of the pasty product. The colored product passage slots descend to the lower end of the inner skirt when the product for scratches is fairly viscous.

EXPOSURE OF THE PROBLEM

With these tubes according to the above description, having longitudinal ribs bordering only on 2 mm the top of the longitudinal slots which extend to the bottom of the inner skirt and extending to the right of the orifice of the neck, experience has shown that fuzzy contours are obtained on the pasty product distributed, especially at the end of dispensing this pasty product. In addition, at the start of pressing the tube, the colored stripes do not appear clearly on the pasty bead until late, typically 10 to 20 mm after the start of this bead.

In addition, and this is embarrassing, experience has shown that with these same tubes, and also with tubes with added striped ends, the slightly deformable inner skirt was often felt by the user as an obstacle at the end of the expulsion of the pasty product.
The Applicant has sought to develop a tube for dispensing a paste with stripes having an integral one-piece skirt with the head of the tube and giving both, with a structure favorable to mass molding, an improved quality of stripes and an appearance of the stripes closer to the beginning of the pasty bead. Incidentally, it also tried to make the interior skirt deformable, in a manner compatible with the preceding requirements and eliminating the discomfort felt by the users at the end of pressing of the tubes.

STATEMENT OF THE INVENTION

The subject of the invention, like the patent already cited FR-B-2 572 366, is a tube for dispensing a dough with stripes comprising a skirt and a head both at least partly made of plastic, the head comprising a neck, said neck carrying an outlet orifice, and below the neck a shoulder having a slightly inclined back surface, by which the head is connected by molding to the skirt of the tube, said head further comprising an inner skirt plastic material which is in one piece with the head and carries openings for the passage of the striped product (s), this skirt and the inside of the neck together forming the outlet conduit for the pasty product and carrying pairs of internal longitudinal ribs of guiding said striped product (s) extending at least from the top of the neck, said head, the outlet orifice of which is optionally surmounted by a tearable lid, forming a unit molded in a single operation on the tube skirt.

• a) le goulot du tube est à double jupe, sa jupe extérieure et sa jupe intérieure partant de son sommet et formant l'intérieur du goulot et donc tout le conduit de sortie du produit pâteux, ses deux jupes définissant entre elles un intervalle annulaire dans lequel pénètre le ou les produit(s) à rayures ;
• b) lesdites ouvertures de passage du ou des produit(s) à rayures sont situées en partie au moins et de préférence entièrement au-dessus du prolongement fictif de la surface envers peu inclinée de l'épaule;
• c) la jupe intérieure porte des nervures intérieures longitudinales freinant le produit pâteux principal, comprenant des nervures allant de chaque ouverture de passage jusqu'à au moins le tiers inférieur de la portion de ladite jupe située sous cette ouverture.

According to the invention, the following three conditions are simultaneously met:

• a) the neck of the tube has a double skirt, its outer skirt and its inner skirt starting from its apex and forming the inside of the neck and therefore the entire outlet duct for the pasty product, its two skirts defining an annular interval between them in which penetrates the striped product (s);
• b) said passage openings of the striped product or products are located at least in part and preferably entirely above the fictitious extension of the slightly inclined back surface of the shoulder;
• c) the internal skirt carries longitudinal internal ribs braking the main pasty product, comprising ribs going from each passage opening to at least the lower third of the portion of said skirt located under this opening.

In the following description and by convention, the vertical direction is that of the axis of the tube, and the term "longitudinal" designates a direction close to the axial direction, the top of the tube corresponding to its neck. The "horizontal" plane is any plane perpendicular to this axis and the words "inclined" or "slightly inclined" relate to the inclination relative to such a horizontal plane.

Thanks to the first means (a), there is an annular gap between the top of the inner skirt and the 'outer skirt or outer wall of the neck, and the colored product enters this annular gap so that, according to the second means ( b), the passage openings of the colored product (s) can be raised in this interval, above the extension of the back surface which is slightly inclined (typically at 20 to 35 °) of the shoulder.

In addition, and in a manner compatible with molding, it has been found necessary for the correct definition of the stripes to provide along (c) the inner skirt with longitudinal inner ribs preceding each opening, the role of such ribs being to slow down the pasty current. main by digging it locally, so that its impact on the streams of striped product (s) leaving the passage openings is reduced.

Overall, thanks to the combination of the three means, the first of these means causing, by reduction in the cross section of the outlet conduit, a slower displacement of the pasty product in this conduit, it has been observed during the comparative use of tubes according to l invention and tubes according to FR-B-2 572 366 of the same dimension (25 ml and skirt diameter 22 mm) and filled with the same products:
a sharp reduction in the length of pasty bead not scratched with the tubes of the invention (for example 5 to 6 mm instead of 15 to 20 mm),
- and a good definition of the colored stripes with these same tubes.

We can notice that thanks to the position of the inner skirt, the annular space between this inner skirt on the one hand and the shoulder and the tube skirt on the other hand is wider than in the case where the inner skirt extends the neck of the tube (FR 2 572 366). This facilitates the filling of the colored product, and this product penetrates more or less, depending on its viscosity, in the already mentioned annular interval which extends this annular space.
A small reserve of colored product is thus obtained at and beyond the passage openings, which is favorable to the regularity of the passage of colored product through these openings and also, as has been observed, to the stability of the aroma of pasty cords.

In order to facilitate the progression of the colored product towards the passage openings, it is very desirable that the reverse surface of the shoulder comprises, between its slightly inclined surface and the internal surface of the external skirt which forms the outside of the neck, an inclined surface forming a chamfer, preferably at 50 to 70 ° relative to the horizontal plane and substantially frustoconical. Such a chamfer increases the inlet diameter of the annular gap, this increase resulting in an increase in the annular cross section of the passage of the colored product towards the passage opening (s) typically reaching 80 to 120%. In addition, this inclined chamfer creates, when the tube is pressed, a stream of colored product along its surface and orienting this colored product upwards, which feeds passage openings located a little higher than in the absence of a chamfer. The top of these openings must then preferably be at the intersection of the fictitious extension of this inclined surface forming a chamfer and the inner skirt or below this intersection. The presence of this circular chamfer facilitates demolding.

Preferably, to have a pressing without difficulty and an emptying at best of the tube, the internal skirt comprises from each passage opening to its lower end a thinned longitudinal zone allowing its flattening. The braking ribs then typically comprise pairs of ribs which frame the passage openings and then the corresponding thinned longitudinal zones. The thinned longitudinal zones are preferably thinned or hollowed out on the external face of the internal skirt, which is favorable for demolding and facilitates access of the product or products for scratches to each of the corresponding passage openings.

The injection molding tool for the interior of the tube according to the invention typically comprises a central tool delimiting the interior of the interior skirt and a peripheral annular tool delimiting the exterior of the interior skirt, these two tools defining by contacts mutual passage openings, and comprising between them below each of these contact areas a longitudinal gap whose thickness is significantly smaller than that of the sectoral gaps corresponding to the molding of other areas or body of the inner skirt. In order to promote demolding, this longitudinal gap is of increasing thickness downwards, while the sectoral gaps corresponding to the molding of the body of the inner skirt have a thickness which varies in the opposite direction.

The inner skirt of the tube of the invention is thus distinguished in that, preferably, the thickness of each thinned longitudinal zone increases from the corresponding passage opening to the lower end of the inner skirt, while the thickness of said body of the inner skirt decreases from said opening at said end. And typically, in axial section, the angle between the two faces of the body of the inner skirt and the angle between the two faces of the thinned longitudinal zones are then both between 0 ° 15 ′ and 1 °.

Also typically, the thickness of each thinned longitudinal region of the inner skirt is between 0.15 and 0.35 mm in its upper half near the corresponding opening and between 0.25 and 0.45 mm in its lower half. Especially in their upper part, each of these longitudinal zones forming the bottom of a groove bordered by the corresponding braking ribs has, at any level perpendicular to the axis of the tube, a thickness much less than the thickness of the body of the inner skirt at the same level. In practice and preferably for saving material and volume, at a given level of the inner skirt, the thickness of this body is between 2 and 4 times the thickness of the thinned areas than in the case of half upper of these zones, and between 1.2 and 3 times the thickness of the thinned zones in the case of their lower half. These arrangements compatible with molding in an industrial series are favorable both for the flattening of the inner skirt at the end of use of the tube and for obtaining good quality of scratches.

It was also surprisingly found that, while with such thinned longitudinal zones not bordered by ribs, colored stripes of variable quality were obtained during use, it was enough to have braking ribs of reduced height 0.2 to 0 , 3 mm to obtain a good quality of scratches in the case of a rather viscous main pasty product. The reduced height of these braking ribs or lower ribs facilitates demolding. In the cases where these longitudinal braking ribs are distributed in pairs framing each passage opening and each underlying longitudinal zone, thinned or not, the braking ribs thus typically have a lower height than the height of the guide ribs and included between 0.2 and 0.7 mm, said height of the guide ribs itself being between 0.4 and 1 mm.

In this regard, it can be noted that the upper ribs or guide ribs of the product (s) for scratches also have a role in braking the main pasty product, and that the minimum heights of each of the two types of ribs, lower and to obtain a good quality of scratches must be increased when the main pasty product is less viscous. The braking ribs may also include longitudinal bosses for additional braking of the main pasty product, located between the pairs of braking ribs framing the passage openings or else between the guide ribs. Preferably, each guide rib extends to the outlet orifice of the tube, the free edge of this rib then being in the extension of the interior surface of this orifice.

In a particularly simple and advantageous manner for the manufacture of molding tools and demolding, the braking ribs and the guide rib bordering each passage opening on the same side form a continuous longitudinal rib of height increasing from bottom to top.

It has been found that, for a given outlet orifice size, it is preferable that the top of the interior skirt, skirt forming the outlet conduit for the pasty product, is connected to the interior surface of the outlet orifice by a converging surface, the cross section of this orifice typically being 0.6 to 0.85 times the lower opening surface of the inner skirt. The height of the outlet orifice being small, typically 1.5 to 3 mm, its narrowing does not cause significant braking, and an outlet duct wider than this orifice is then preferable, as has been observed, to a narrower outlet duct with connection surface to the divergent orifice. In addition, to facilitate demolding, the inner skirt has an inner diameter which gradually decreases a little from the bottom up.

As already mentioned, the fragrance of the pasty product is fairly well preserved due to the presence of a reserve of product for scratches in the annular interval. Preservation of aromas can however be improved by lining the back of the shoulder of the tube with a metalloplastic or plastic complex annular washer fixed by molding, this washer comprising at least external layers of polyethylene, or possibly of polypropylene, and an intermediate layer aluminum or plastic barrier.

Furthermore, to distribute a paste with stripes of different colors or natures, the tube of the invention has partitions dividing into sectors, which each contain a passage opening, the interval between its inner skirt and its shoulder. These partitions and these passage openings are typically in the same number between 2 and 6.

EXAMPLES

• La figure 1 représente le haut d'un tube selon l'invention, en coupe axiale.
• Les figures 2 et 4 représentent des coupes A-A, C-C et B-B perpendicu­laires à l'axe de la tête de ce tube.

The examples and the drawings will make it possible to complete the description of the tube of the invention.

• Figure 1 shows the top of a tube according to the invention, in axial section.
• Figures 2 and 4 show sections AA, CC and BB perpendicular to the axis of the head of this tube.

The head 1 of the tube of FIG. 1 comprises a shoulder 2, the lower end of which is connected by molding at the junction 3 to the skirt 4 of the tube with the outside diameter 22 mm. The head 1 comprises a top part 5 carrying in its center the outlet orifice 6 with an internal diameter of 7.5 mm and, connecting to this top 5, an external skirt 16 forming the threaded outside of the neck 7 and connecting to the shoulder 2 and an inner skirt 8 18 mm high forming the inside of the neck 7 and alone constituting the entire outlet duct 8 of the pasty product. The inner surface of the outer skirt 16 has a diameter of 12 mm, and the top of the inner skirt 8 with an outer diameter of 10 mm is separated from the outer skirt 16 by the annular gap 9 of width 0.9 to 1 mm . The reverse surface of the shoulder 2 comprises, between its surface 10 inclined at 30 ° and the internal surface 11 of the outer skirt 16, a frustoconical chamfer 12 inclined at 60 ° doubling the annular surface for the passage of the colored product towards the passage openings in the outlet conduit such as 13 and 14.

The inner skirt 8 carries five passage openings regularly distributed around its periphery, three of them 13,14,15, appearing in FIGS. 1 to 4, each 14 being of substantially rectangular contour 0.8 x 1.1 mm according to its longitudinal direction and being framed by two longitudinal ribs 17 and 18 which extend from a level located 1 mm from the lower end 19 of the outer skirt 8 to the lower end 20 of the outlet orifice 6. These ribs 17 and 18 have a height which increases steadily from the bottom upwards, this height thus varying from 0.3 to 0.5 mm in their braking part only 26 below the openings such as 14 and from 0, 5 to 0.6 mm in their guiding and braking part going from these openings such as 14 to the orifice 6. The upper edge or free edge 21 of each rib such as 22 is in line with the internal surface 23 of the outlet 6, so as not to leave any roughness catching the pasty product in its progression. Each passage opening such as 13 or 14 is entirely between the fictitious extensions of the slightly inclined surface 10 and of the frustoconical chamfer 12 of the reverse surface of the shoulder, the bottom 24 of these openings being about 0.5 mm above the slightly inclined surface 10 and the inner skirt 8.
With the bottom such as 24 of each opening such as 14 begins a thinned longitudinal zone 25, of the same width 0.6 mm as the opening on the external side 14, descending to the bottom of the inner skirt 8, its thickness then increasing regularly from 0.2 mm below the opening 14 to 0.3 mm at the bottom of the skirt. This thinned zone 25 is bordered over most of its length by the lower braking portions such as 26 of the longitudinal ribs 17 and 18. The thickness of the body 27 of the inner skirt 8 decreases regularly from top to bottom, from 0.8 mm thick to 0.6 mm. Figures 1 to 3 show in axial sections the position of the longitudinal ribs and the grooves 28 and 32 that they delimit. The top groove 28 or guide groove (fig. 1 and 2) has, between its portions of ribs used for guiding the colored product such as a thinned bottom 31 of 0.8 mm thickness, while the bottom groove 32, which extends this top groove 28 and serves for braking the main pasty product stream before it arrives at the openings such as 13 and 14, has between its portions of braking ribs such as 26 a bottom formed by the longitudinal zone thinned 25 of thickness varying from 0.2 to 0.3 mm (fig. 3). The thinning of the lower edge 33 of each opening such as 13 (Figures 1 and 4) facilitates the crossing of the striped product there.
The inner skirt 8 is slightly frustoconical or convergent, its inner diameter varying from 9 mm at its lower open end to 8.4 mm at its upper part. This upper part is connected by a converging connection surface 34 to the internal surface 23 of the outlet orifice 6, with an internal diameter of 7.5 mm and a height of 2 mm. These arrangements are favorable for molding, and the straight inlet sections of the inner skirt and of the outlet orifice are respectively 63 mm² and 44 mm², allowing easier progression of the pasty product towards the outlet orifice 6 .

As a variant, for a less viscous colored product, the inner skirt 8 is provided with 5 additional longitudinal braking bosses such as 35 (FIG. 2), forming flats of width 2 mm and of thickness 0.5 mm each located between the pairs of ribs such as 17 and 18 framing two adjacent openings 13 and 14. These bosses 35 extend here over the entire height of the longitudinal ribs such as 17.

In FIG. 1, the position of a metalloplastic annular washer 36 with 5 layers forming a barrier for perfumes, inlaid on the reverse side 10 and 12 of the shoulder 2 and linked to this shoulder 2 by molding, has been indicated in addition. , its surface layers being made of polyethylene. This flexible washer 36 is threaded around the annular tool forming the annular chamber 37 and the annular gap 9, which is particularly simple.

TESTS

• 1/5 tubes were compared in accordance with the preceding description, the head 1 being made of polyethylene and the skirt 4 being metalloplastic, having no bosses 35 or metalloplastic washer 36, with 3 tubes according to the prior art (FR 2 572 366) with the same 25 ml capacity and the same outlet orifice (7.5 mm) and skirt (22 mm) diameters, with the same pasty products in the two types of tubes. The tests for the distribution of the pasty product give, in the case of the tubes of the prior art, colored stripes of not clear outline. In the case of the tubes according to the invention, we have obtained:
  - markedly earlier onset of scratches, 5 to 6 mm from the start of the pasty bead, instead of 15 to 20 mm with the tubes of the prior art;
  - well defined stripes with sharp edges;
  - no difficulty in pressing tubes at the end of use.
• 2 / With a main pasty product and a less viscous colored product than in the previous case, the sharpness of the colored stripes was improved with tubes according to the invention provided with longitudinal bosses such as 35.
• 3 / Three tubes of the same geometry were prepared as in the first series of tests, the structure of each tube being completed by five radial partitions situated between the openings for the passage of the pasty product and with a horizontal lower edge placed just below the shoulder, the position 38 of this lower edge being identified in FIG. 1.
  Attempts were then made to distribute the pasty product with five different colored products placed for each tube in each of the sectors delimited by the preceding radial partitions. The distribution tests gave stripes of the five colors of excellent definition on the pasty cords obtained.
• 4 / Tubes with a skirt diameter of 35 mm and a capacity of 150 ml of product were produced with the same head structure, the shoulder 2 being simply extended externally for its connection to the skirt. The gap and the annular chamber were filled with product for scratches to the same level, substantially at the bottom 38 of the shoulder 2 (FIG. 1). It was found that the expulsion of the pasty product was easy, with stripes appearing early and very clear. It was also noted that the scratches persisted until the end of distribution of the pasty product.

ADVANTAGES OF THE INVENTION

It provides both:
- early appearance of colored stripes;
- particularly well-defined stripes, with sharp contours;
- an easy one-piece molding design, suitable for mass production;
- and according to the last test, a head structure capable of adapting to various capacities, with non-critical adjustment conditions;
- Possibly, thanks to the thinned longitudinal zones, a tube head with an internal skirt which is flattened without annoying effort at the end of use.

Claims (14)

1. Tube for dispensing a paste with stripes comprising a skirt (4) and a head (1), both at least partly made of plastic, the head (1) comprising a neck (7), said neck ( 7) carrying an outlet orifice (6), as well as below the neck (7) a shoulder (2) having a slightly inclined annular surface (10), by which the head is connected by molding to the skirt (4 ) of the tube, said head (1) further comprising an inner skirt (8) made of plastic material which is integral with the head (1) and carries passage openings (13,14,15) of the product (s) striped, this skirt (8) and the inside of the neck (7) carrying pairs of internal longitudinal guide ribs (17, 18, 22) of said striped product (s) extending at least from said openings passage (13, 14, 15) which they frame up to the top of the neck (7), said head (1), the outlet orifice (6) of which is possibly surmounted by a tearable lid, fo rmant an assembly molded in a single operation on the skirt (4) of the tube, characterized in that: a) the neck (7) of the tube has a double skirt, its outer skirt and its inner skirt (8) starting from its top (5) and forming the inside of the neck (7) and therefore the entire outlet duct (8 ) of the pasty product, its two skirts (16) and (8) defining between them an annular gap (9) into which the striped product or products penetrate; b) said passage openings (13, 14, 15) of the striped product (s) are located at least partly above the notional extension of the slightly inclined back surface (10) of the shoulder (2) ; c) the internal skirt (8) carries longitudinal internal ribs (26, 35) braking the main pasty product, comprising ribs 26) going from each passage opening (14) to at least the lower third of the portion of said skirt (8) located under this opening. 2. Tube according to claim 1, characterized in that the back surface of the shoulder (2) comprises, between its slightly inclined surface (10) and the internal surface (11) of the outer skirt (16), a surface inclined forming a chamfer (12). 3. Tube according to claim 2, characterized in that the inclined surface forming a chamfer (12) is substantially frustoconical and at 50 to 70 ° relative to the horizontal plane. 4. Tube according to any one of claims 2 or 3, characterized in that the top of each passage opening (13,14,15) is at the highest at the intersection of the fictitious extension of the inclined surface forming a chamfer ( 12) and the inner skirt (8). 5. Tube according to any one of claims 1 to 4, characterized in that the inner skirt (8) has from each passage opening (14) to the bottom (19) of said skirt a thinned longitudinal zone (25) , its braking ribs (26) comprising pairs of ribs (17 and 18) which frame said passage openings (14) then said thinned areas (25). 6. Tube according to claim 5, characterized in that said thinned longitudinal zones (25) are thinned on the external face of the inner skirt (8) and in that the thickness of each thinned longitudinal zone (25) increases by going from the corresponding passage opening (13,14) to the lower end (19) of the inner skirt (8), while the thickness of the body (27) of the inner skirt (8) decreases from said opening (13,14) at said end (19). 7. Tube according to claim 6, characterized in that, in axial section, the angle between the two faces of the body (27) of the inner skirt (8) and the angle between the two faces of the thinned longitudinal zones (25 ) are both between 0 ° 15 ′ and 1 °. 8. Tube according to claim 7, characterized in that the thickness of each thinned zone (25) is between 0.15 and 0.35 mm in its upper half, and between 0.25 and 0.45 mm in its lower half. 9. Tube according to claim 8, characterized in that at a given level of the inner skirt (8), the thickness of its body (27) is between 2 and 4 times the thickness of its thinned areas (25) in the case of the upper half of said areas and between 1.2 and 3 times the thickness of its thinned areas (25) in the case of the lower half of said areas. 10. Tube according to any one of claims 5 to 9, characterized in that the braking ribs (26,35) also include longitudinal bosses (35) for additional braking of the main pasty product, located between the pairs of ribs of braking (17,26 and 18) framing the passage openings (13,14) or between the pairs of guide ribs (17,18). 11. Tube according to any one of claims 5 to 9, characterized in that the braking rib (17 or 26,18, 22) and the guide rib (17,18,22) bordering each passage opening (13 , 14) on the same side form a continuous longitudinal rib (17,18,22) of height increasing from the bottom to the top. 12. Tube according to any one of claims 1 to 4, characterized in that the top of the inner skirt (8) is connected to the inner surface (23) of the outlet orifice (6) by a converging surface ( 34), of the cross section of this orifice (6) being equal to 0.6 to 0.85 times the lower opening surface (19) of said inner skirt (8). 13. Tube according to any one of claims 1 to 12, characterized in that the back of the shoulder (2) is lined with an annular washer (36) fixed by molding, this washer (36) comprising at less outer layers of polyethylene and an intermediate layer of aluminum or barrier plastic. 14. Tube according to any one of claims 2 to 9, for dispensing a paste with stripes of different colors or natures, characterized in that it comprises partitions dividing into sectors each containing a passage opening (13 , 14,15) the interval between the inner skirt (8) on the one hand and the outer skirt (16) and the shoulder (2) of the tube on the other hand, said partitions and said passage openings (13,14,15) being at the same number between 2 and 6.

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