FR2786468A1 - Flexible tubular packaging container for soap, detergent, cosmetic, pharmaceutical, etc. has dispensing head with elastic membrane having cut(s) restricting passage of container contents - Google Patents

Abstract

A flexible tubular packaging container has a dispensing head at one end. The head has an elastic membrane mounted in a port and having cut(s) restricting the movement of the container contents through a passage in the head. The periphery of the membrane is retained by the material of the head. Independent claims are included for the following: (a) Manufacturing the above container by injection molding where the precut membrane is installed in the mold prior to injecting the molten plastic. (b) Manufacturing the above container by extruding a flexible sleeve, placing this onto a mandrel, fitting the pre-cut membrane onto an end of the mandrel and extruding the dispensing head onto the mandrel. Preferred Features: The membrane periphery fits into a groove in a wall of the dispensing head. The membrane is convex and depending on the pressure of the container contents extends out of or into the container.

Description

 The present invention relates to a packaging tube, of the type comprising a flexible tubular body provided, at one end, with a dispensing head delimiting a flow passage for the contents of the tube.

 The invention further relates to methods of manufacturing a blank for a tube as defined above.

 The packaging tubes are commonly used for packaging cosmetic or pharmaceutical products, detergents, or soapy solutions.

 The packaging tubes are appreciated because of their low manufacturing cost.

 In order to guarantee the stability of the product contained in the packaging tube, it is fitted with a removable closure cap.

 Between two withdrawals of product in the tube, it is frequent that the user forgets to replace the stopper, which leads either to a deterioration of the product, or to risks of leakage by the dispensing orifice.

 The object of the invention is to provide a dispensing tube which, despite the absence of the stopper, makes it possible to guarantee satisfactory preservation of the product, and to avoid any risk of sagging, while keeping the tube a low manufacturing cost.

 To this end, the subject of the invention is a packaging tube of the aforementioned type, characterized in that characterized in that the dispensing head carries an elastic membrane notched with at least one incision delimiting said flow passage for the contents of the tube, which membrane is mounted in a lumen of the dispensing head, and in that the dispensing head comprises means for retaining the periphery of the membrane, which retaining means came integrally with the head of distribution.

According to particular embodiments, the packaging tube includes one or more of the following characteristics:
the membrane is embedded at its periphery in the thickness of a wall of the dispensing head;
at rest, the membrane is curved, and protrudes inside the tube;
the membrane is elastically deformable under the action of the pressure of the contents of the tube between its rest position in which it projects inside the tube and a position of ejection of the contents of the tube in which it projects at outside the tube; and
the membrane has at its periphery an annular rim oriented towards the outside with which the retaining means cooperate.

The invention further relates to a method for manufacturing a blank for a tube as defined above, characterized in that it comprises the steps consisting in:
a-arrange the elastic membrane previously notched in a mold delimiting the shape of the body and of the distribution head of the tube; and
b-inject, into the mold containing the membrane, liquid plastic to simultaneously form the body and the dispensing head of the tube.

Another subject of the invention is another method of manufacturing a tube blank as defined above, characterized in that it comprises the steps consisting in:
a-extruding a flexible cylindrical sleeve intended to form the body of the conditioning tube;
b-arrange the sleeve around a mandrel, the end of which projects from the sleeve and defines the internal profile of the tube distribution head;
c-put in place, at the end of the mandrel, the elastic membrane previously notched with at least one incision; and
d-extruding the dispensing head on the projecting end of the mandrel and on the periphery of the membrane using a matrix delimiting an imprint, ensuring a connection of the dispensing head to the sleeve.

The invention will be better understood on reading the description which follows, given solely by way of example and made with reference to the drawings, in which:
Figure 1 is an elevational view with partial cutaway of a packaging tube according to the invention;
Figure 2 is an enlarged sectional view of the detail of the connection of the elastic membrane to the head of the tube of Figure 1;
Figure 3 is a sectional view of the dispensing head when removing the product;
Figures 4 and 5 are partial views in longitudinal section of a mold for the manufacture of the tube of Figure 1, according to a first method;
Figure 6 is a perspective view of part of an installation for manufacturing a tube according to the invention, according to another manufacturing process;
Figures 7 and 9 are partial sectional views of the installation illustrating successive stages of the second method of manufacturing a tube according to the invention; and
Figures 8 and 10 are enlarged views of the region of Figures 7 and 9 having the membrane.

 The tube 10 shown in FIG. 1 comprises a flexible tubular body 12 closed at one end by a transverse weld 14 and having, at its other end, a distribution head 16. This delimits an orifice 18 in which a membrane is arranged 20 elastically deformable. The tube 10 also includes a plug 24 secured to the dispensing head 16 by a hinge 24.

 The tube 12 has, for example in section, an elliptical shape. The body 12, the head 16 and the plug 22 are produced by injection from a single piece and are for example formed from polyethylene or polypropylene.

 In the region connecting the body 12 to the dispensing head 16, the tube has a peripheral shoulder 26 extended by the hinge 24.

 The head 16 is delimited by a cylindrical side wall 28 in the shape of an ellipse. The side wall 28 is closed by an end wall 30 extending transversely and at the center of which the orifice 18 is delimited.

 The membrane 20 has a hemispherical wall 32 in the form of a bowl. At rest, it protrudes inside the tube. It is notched substantially at its center by two perpendicular incisions 34 forming a cross. These incisions 34 delimit a flow passage for the content of the fluid.

 The hemispherical wall 32 of the membrane is bordered by a centripetal annular rim 36 forming the planar periphery of the membrane.

 As shown on a larger scale in FIG. 2, the dispensing head comprises means 38 for retaining the periphery 36 of the membrane. These retaining means came integrally with the distribution head 16.

 More specifically, in the embodiment shown, the rim 36 of the membrane is embedded at its periphery in the thickness of the end wall 30 of the dispensing head. Thus, the periphery of the lumen 18 is defined on either side of the rim 36 by two centripetal annular extensions 40A, 40B between which the peripheral rim 36 is retained.

 The membrane 20 is made of an elastically deformable material. It has a thickness adapted so that its elasticity is greater than that of the walls defining the dispensing head 16.

 The plug 22 internally delimits a cup of shape complementary to that of the dispensing head 16. It has, in its middle, a hemispherical bending 50 of shape complementary to that of the membrane 20, when the latter is in its rest position . The bending 50 is adapted to be engaged in the lumen 18 and to be kept in contact with the membrane 20, when the plug 22 is placed on the dispensing head 16.

 In addition, a lug 52 for holding the plug 22 is provided on the side wall 28 of the dispensing head.

 It is understood that, when the user exerts pressure on the body 12, the membrane 20 under the action of the product contained in the tube deforms elastically until its curvature is reversed and it projects towards the exterior, as shown in Figure 3.

 Under the action of pressure, the membrane 20 deforms enough for the product contained in the tube to escape through the dispensing orifice delimited by the incisions 34.

 When the pressure on the tube ceases, the membrane returns by elasticity in its rest position, protruding inside the tube. In this position, the facing edges of the incisions 34 are in contact with one another, thus ensuring effective sealing of the tube, in the absence of pressure on the body.

 In Figures 4 and 5 is shown a mold for manufacturing a blank of the tube of Figures 1 to 3, according to a first method according to the invention.

 A tube blank is formed by the tube before filling, the transverse weld 14 having not yet been produced.

 The injection mold for the packaging tube comprises an external half-mold 102 and an internal half-mold 104.

 The external half-mold 102 defines an imprint 106 defining the external shape of the dispensing head 16 and of the body 12 of the tube. The external half-mold 102 also delimits the imprint of the plug 22 and the hinge 24. Only the passage 108 defining the hinge 24 is shown in FIG. 4.

 The internal half-mold 104 is adapted to be kept inside the cavity 106. it defines the internal profile of the dispensing head 16 and of the body 12. Thus, the external 102 and internal half-molds delimit between them a gap 110 whose width corresponds to the desired thickness for the walls of the body 12 and of the dispensing head 16.

 In order to ensure an axial positioning of the two half-molds with respect to each other and to support the membrane 20, each half-mold is provided axially with a sliding drawer, denoted 112 and 114 respectively, for the half - external mold 102 and the internal half-mold 104.

 These drawers are cylindrical of revolution and are sliding in coaxial bores of the molds. Their diameter is both the outside diameter of the rim 36 of the membrane.

 At their opposite ends, the drawers 112 and 114 have complementary protruding and recessed profiles.

 In particular, the external slide 112 has a hemispherical bending 116 whose radius corresponds to the radius of curvature of the membrane 20 at rest.

 Conversely, the internal drawer 114 defines a hemispherical cup 118 whose radius corresponds to the radius of curvature of the hemispherical wall 32.

 The bending 116 and the cup 118 are both bordered by an annular area on which the rim 36 of the membrane 20 is supported, when the latter is sandwiched between the two drawers.

 Furthermore, at their periphery, the two drawers 112,114 have peripheral shoulders 120,122 defining on either side of the rim 36 of the reservations defining the extensions 40A, 40B.

 The height of the shoulders 120,122 is adapted so that, when the membrane 20 is inserted between the drawers 112 and 114, the difference between the two drawers, measured in the region of the shoulders 120 and 122, is exactly equal to the thickness of the end wall 30 of the dispensing head.

 The drawers 112 and 114 are movable between an initial position and a final injection position. In the initial injection position, shown in FIG. 4, the external drawer 112 projects inside the internal half-mold 104 and the internal drawer 114 is completely retracted there. In the final injection position, as shown in FIG. 5, the shoulders 120 and 122 extend the corresponding surfaces of the external 102 and internal 104 mold halves intended to define the end wall 30.

 In order to ensure the manufacture of the blank of the tube shown in FIGS. 1 to 3, the membrane 20 is first produced separately by injection.

It is cut with incisions 34. It is then placed between the two drawers 112 and 114. These are brought into the initial injection position shown in FIG. 4, by enclosing the membrane between them. In this position, the drawers 112 and 114 ensure axial positioning of the two half-molds 102 and 104.

 By means known per se, thermoplastic material is injected in the interval 110, while the drawers 112 and 114 are held in their initial position.

 After most of the interval 110 is filled, the two drawers are moved simultaneously to come to the position in FIG. 5. The injection then continues until the interval 110 is completely filled. During this phase injection, thermoplastic material flows into the annular spaces defined by the shoulders 120 and 122, thus forming the extensions 40A, 40B between which is embedded the peripheral rim 36 of the membrane.

 After cooling, the tube blank thus formed is extracted from the mold.

 It is understood that with such a manufacturing process, the tube being produced in a single operation around the membrane constituting an insert, the manufacturing cost thereof is reduced.

 FIG. 6 shows another arrangement for manufacturing a blank for a tube according to the invention.

 According to this method, a sleeve 200, made of plastic by extrusion, is engaged around a mandrel 202. The sleeve 200 is intended to constitute the body of the tube.

 The mandrel 202 has, at its end, a profile with the desired shape for the interior surface of the tube distribution head. In the example shown in Figures 7 to 10, the mandrel 202 has from its periphery an annular area 204, followed by a frustoconical converging profile 206 extended by a cylindrical section 208. The end surface 210 of the cylindrical section 208 is provided axially of a hemispherical bowl 212 intended to receive the notched elastic membrane denoted 214.

 The bowl 212 is bordered by a peripheral collar 215 defining outwardly a shoulder 216. Thus, as shown on a larger scale in FIG. 8, after the membrane 214 has been placed in the bowl 212, the contour of the peripheral rim of the membrane overhangs the shouldered end surface 210.

 Furthermore, the tooling for manufacturing the tube comprises a complementary upper matrix 220 shown in FIGS. 7 to 10. This defines an internal imprint 222 delimiting the external shape of the dispensing head.

 The matrix 220 has axially a sliding drawer 224 the end of which is hemispherical and has a profile similar to that of the membrane 214. The hemispherical end is bordered by a flat annular area extending over only part of the rim of the membrane 214.

 As shown in FIGS. 7 and 8, after fitting the sleeve 200 around the mandrel 202 and depositing the membrane 214 inside the cup 212 bearing on the collar 215, a torus 228 of liquid thermoplastic material is deposited on the end face 210 of the mandrel.

The slide 224 being applied to the hollow surface of the membrane 214, the matrix 220 is advanced axially towards the vertically arranged mandrel 202, which causes the extrusion of the torus 228 in the interval delimited between the mandrel 202 and the matrix 220 .

 Thus, at the end of extrusion, as shown in FIGS. 9 and 10, the die 220 is stopped at a predetermined distance from the mandrel 202. In this position, the material coming from the torus 228 completely fills the gap between the mandrel 202 and the matrix 220 from the drawer 224 to the sleeve 200 partially covering the latter.

 Due to the presence of the shoulder 216, the material from the torus 228 is listened to on either side of the peripheral rim of the membrane 214, thus ensuring its embedding in the thickness of the wall thus extruded from the head of distribution.

 With such a manufacturing process, the cost of manufacturing the tube is reduced, since the mounting and connection of the membrane 214 are carried out simultaneously with the manufacture of the tube distribution head.

 Whatever the manufacturing process used, the tube, due to the presence of the elastically notched deformable membrane with at least one incision, allows the product contained inside the tube to be protected even in the absence of the plug. shutter.

Claims (7)

 1.-Packaging tube (10), of the type comprising a flexible tubular body (12) provided, at one end, with a distribution head (16) defining a flow passage (34) for the contents of the tube, characterized in that the dispensing head (16) carries an elastic membrane (20) notched with at least one incision (34) delimiting said flow passage for the contents of the tube, which membrane (20) is mounted in a light (18) of the dispensing head (16), and in that the dispensing head (16) comprises means (38) for retaining the periphery (36) of the membrane (20), which retaining means (38) came integrally with the distribution head (16).  2.-conditioning tube according to claim 1, characterized in that the membrane (20) is embedded at its periphery in the thickness of a wall (30) of the dispensing head (16).  3. A conditioning tube according to claim 1 or 2, characterized in that, at rest, the membrane (20) is curved, and protrudes inside the tube.  4. A conditioning tube according to claim 3, characterized in that the membrane (20) is elastically deformable under the action of the pressure of the contents of the tube between its rest position in which it projects inside the tube and a position for ejecting the contents of the tube in which it projects outside the tube.  5.-conditioning tube according to any one of the preceding claims, characterized in that the membrane (20) has at its periphery an annular flange (36) oriented towards the outside with which the retaining means (38) cooperate.  6.- A method of manufacturing a tube blank according to any one of claims 1 to 5, characterized in that it comprises the steps consisting in:  a-dispose the elastic membrane (20) previously notched in a mold (100) defining the shape of the body (12) and of the dispensing head (16) of the tube; and  b-inject, into the mold (100) containing the membrane (20), liquid plastic to simultaneously form the body (12) and the dispensing head (16) of the tube.  7.- A method of manufacturing a tube blank according to any one of claims 1 to 5, characterized in that it comprises the steps consisting in:  a-extruding a flexible cylindrical sleeve (200) intended to form the body of the conditioning tube;  b-arrange the sleeve (200) around a mandrel (202), the end of which projects from the sleeve (200) and defines the internal profile of the tube distribution head;  c-put in place, at the end of the mandrel (202), the elastic membrane (214) previously notched with at least one incision; and  d-extruding the dispensing head on the projecting end of the mandrel (202) and on the periphery of the membrane (214) using a matrix (220) delimiting an imprint (222), ensuring a connection from the distribution head to the sleeve (200).