MXPA06000719A

MXPA06000719A - A tube made in a single piece by injection of a plastic material.

Info

Publication number: MXPA06000719A
Application number: MXPA06000719A
Authority: MX
Inventors: Emilio Morini
Original assignee: Bormioli Rocco & Figlio Spa
Priority date: 2004-10-20
Filing date: 2004-10-20
Publication date: 2006-06-05
Also published as: BRPI0412144A; EP1802532A1; US20070108227A1; CA2528523A1; WO2006043288A1

Abstract

The tube (1) comprises a bottom part (1a), open for introduction of a product, which is then closable, and a top part (1b) which has a through-hole (2) for passage and exit of the product from the tube. The bottom part (1a) is delimited by a lateral surface which exhibits a smaller thickness than a thickness of a lateral surface of the top part (1b) which delimits a remaining part of the tube (1). The top part (1b) comprises an opening (3), which is larger than the through-hole (2) and is arranged in a zone of the top part (1b) in which the through-hole (2) is to be located, in which opening a reducer (4) is sealingly fitted, and in which reducer (2) the through-hole (2) is afforded.

Description

SINGLE PIECE PIPE OBTAINED BY INJECTION OF PLASTIC MATERIAL FIELD OF THE INVENTION The present invention relates to a one-piece tube obtained by injection of plastic material.

BACKGROUND OF THE INVENTION Plastic tubes have been used for a long time to replace the well-known tubes made of metal material; in particular reference is being made to tubes intended to contain fluid products, such as for example creams and cosmetic products in general, which are made of soft material that allows the product contained within the tube to be produced by crushing the tube itself and its deformation of predominantly elastic type. These tubes usually comprise an open lower part for the introduction of the product and which can be sealed in a sealed manner after said introduction; furthermore, they comprise an upper part having a through hole for the exit of the product from the tube; these tubes are made by welding the upper part, usually obtained by injection molding, to a cylindrical tube, or by directly molding the entire tube by injection of plastic material in a suitable mold. The present invention relates specifically to this last type of tubes. The tubes made in this way are sent to the companies producing the products, which proceed to fill the tubes by introducing the product from the lower open part, to weld the lower part and to close, in a removable way, the through hole of the top through a plug that will allow the user to open the tube to cause the dosed output of the tube product and close the tube before the subsequent use. The closure of the through hole is generally obtained by means of a plug screwed on a thread made in correspondence of the through hole or with a pressurized cap provided with an appendix that is inserted hermetically in the through hole. The realization of the tube of a single piece by injection of plastic material bears, for the manufacturer, problems due to the minimum thickness of the wall of the tube that can be obtained by injection without too many discards of production; specifically, such thickness can not be less than approximately 0.6 - 0.65 millimeters. On the other hand, a high thickness of the tube wall entails problems for the user, in particular related to closing the lower part of the tube.

BRIEF DESCRIPTION OF THE INVENTION The object of the present invention is to eliminate said drawbacks by providing a tube obtained in one piece by injection of plastic material which is easy to manufacture and easy to use. Another object of the present invention is to provide a tube, which can be made using molds capable of producing a large number of parts without deterioration. An advantage of the present invention is to allow a higher standardization of the molds used to make the tubes in question. Another advantage of the present invention is that of proposing a simple and easy to implement solution. These objectives and advantages and still others are achieved in their entirety by the present invention, as characterized by the claims that follow.

BRIEF DESCRIPTION OF THE FIGURES Other features and advantages of the present invention will become even more apparent from the detailed description that follows of embodiments of the present invention, illustrated by way of an illustrator and not limiting in the attached figures, in which: - the figure 1 shows a cross section in vertical elevation of a first possible embodiment of the tube in object; Figure 2 shows, on an amplified scale, a detail of figure 1 corresponding to the lower part of the tube; - figure 3 shows, on an amplified scale, a detail of figure 1 corresponding to the upper part of the tube; - Figure 4 shows a cross section in vertical elevation of another possible embodiment of the upper part of the tube in question.

DESCRIPTION OF THE PREFERRED MODALITIES The tube (1) in question is of the type made in one piece by injection of plastic material, generally a soft material such as polyethylene, in a mold made for this purpose; "tube made in one piece" means a tube that leaves a single injection molding operation already formed with its lateral body open on the bottom side, for the introduction of the product, and provided with its upper part, or completely formed, in which the outlet orifice of the product that the tube is intended to contain has been obtained or, as will be better described below, an outlet orifice to which eventually a reducer can be applied to reduce the diameter of the exit orifice in function of the products, more or less fluid, to supply.

In addition, with the same molding operation it is possible to make the "cap" that closes the exit orifice; This plug, which to be rigorous, is not part of the tube, can be made even as a separate element. The object of the present invention, moreover, relates specifically to one-piece tubes made by injection molding of plastic material since such technology, which presents undoubted advantages with respect to other technologies, it can be said that it has problems that make its application; the solutions proposed by the present invention, therefore, tend to overcome the problems concerning such technology. The tube in question, as well as tubes of known type, comprises an open lower part (1a), through which it will be made, in the packaging establishments of the products to which such tube is intended, the introduction of the product; after the introduction of the fluid product, the lower part of the tube is closed, for example by thermal welding. The tube, in addition, is provided with an upper part (1b) in which there is a through hole (2) for the exit of the product from the tube in the phase of use of the product by the end user. The tube in question can be, as for example illustrated in the detail of Figure 4, of the type comprising a threaded mouth (1c), of essentially cylindrical shape, on which a closure plug is screwed. In particular, the upper part (1b) of the tube in question comprises an opening (3), of circular section, having dimensions greater than the dimensions of the through hole (2) and which is concentric therewith. A reducing element (4) is provided, which is carried out separately by molding or other known methods, shaped so as to be sealed, in a sealed manner, in the opening (3); the through hole (2) is obtained in the reducing element. The element (4) can also be welded, for example by thermal welding, in correspondence of the opening (3). The reducing element (4) has an extremely simple shape and can be obtained with elementary and inexpensive means; in particular, the reducing element (4) comprises a disc (4b), in which the through hole (2) is made, which rests on the upper part of the threaded mouth when an external ring (4a) of the element reducer (4) fits into the opening (3). This embodiment allows an easy embodiment by injection of the tube since its upper part has an opening (3) which, independently of the diameter desired for the through hole (2), has a diameter such as to allow the use of pins for the realization of the opening (3) of a very large diameter (equal to that of the opening (3)) that does not cause the drawbacks that, on the contrary, would cause the dowels of a smaller diameter (equal to that of the hole (2)). In this way, for a certain tube format that determines the useful internal volume of the same tube, it is also possible to have molds of standard type that make the tube with the opening (3) of standard dimensions, and have several molds, extremely simple and economic, that realize reducing elements (4) with different dimensions of the through hole (2); In this way, it is possible to realize a remarkable range of tubes with expenses for the realization of extremely reduced molds. Also, generally a film (5) is provided which is thermally welded on the upper part of the disk (4b) so as to close the through hole (2); This film is removed by the user at the time of first use of the tube and serves as a guarantee seal for the product contained in the tube itself. In addition, the tube can be, as for example the one illustrated in FIGS. 1 and 3, of the type comprising a snap-on cap (6) which is hinged to the body of the tube and is obtained directly by injection together with the body of the tube, with a material equal to that with which the body of the tube is obtained or different from that with which the body of the tube is made; In general, a more rigid material is used, such as polypropylene. The plug (6) is provided with an appendix (6a) that is hermetically inserted in the passage orifice (2) of the tube. Also in this case an opening (3) of a larger diameter is made with respect to that of the through hole (2); therefore, also in this case a reducing element (4) is provided comprising an annular crown (4c) that rests on the internal wall of the upper part of the tube when an outer ring (4a) of the reducing element (4) it fits into the opening (3); furthermore, an internal ring is provided, concentric to the outer ring (4a), which defines the through hole (2) and is suitable for housing the appendix (6a). The part . The upper part of the tube, from which the product contained in the same tube comes out during its use, can still be made in any other way, although the types indicated are those that allow for an easier embodiment of the tube in a single injection of plastic material. The lower part (1a) of the tube, in all its possible embodiments, is delimited by a lateral surface that has a thickness less than that of the lateral surface delimiting the remaining part of the tube. In particular, the lateral surface of lower thickness has a height, starting from the lower end of the tube, which is variable, also in relation to the total dimensions of the tube, from a few millimeters to 1-2 centimeters. Since these tubes normally have a height between a few centimeters and 15-20 centimeters, the part of the side surface having a smaller thickness represents approximately one tenth of the total height of the tube. In order to be able to carry out the injection molding in a single piece of the tube, the thicknesses of its wall must be at least 0.6-0.65 millimeters in order to avoid having a non-tolerable quantity of production discards. This thickness value of the tube wall, however, represents an obstacle for the users of the tubes since it is difficult or at least long and wasteful to close the lower part of the tube; in effect, the tube must be supplied open from the bottom side to allow the introduction of the product in the same tube. In contrast, according to the present invention the lower part (1a) of the tube is made with a thickness comprised between 0.40 and 0.55 millimeters.

Given the low height of the part made with a lower thickness, there are no major problems during the injection molding stage of the tube, which, on the other hand, would be in the case that the entire side surface of the tube were attempted with such reduced thicknesses. The reduced thickness of the lower area of the tube, however, makes it possible, or at least much more, easy, quick and safe, to close the same tube. The reduction of the thickness of the lateral surface of the lower zone of the tube is preferably obtained by keeping the external diameter of the tube unchanged and increasing the internal diameter of the same tube; obviously, in the case of a tube with a barely conical shape, the increase in the internal diameter of the zone of reduced thickness will be obtained by means of an internal connection zone (10) with a taper angle much greater than that of the tube. Obtaining the reduction of the thickness of the lower part of the tube is a very easy operation that requires modest modifications in the molds, even existing, that can be easily made by a mold technician. In addition, the shape suggested by the present invention does not involve scouring that can make it difficult to remove the central part of the mold. The adoption of the simple solutions described in the present invention provides the possibility of using, in order to obtain the tubes described, the plastic injection molding technology that allows a considerable reduction in processing costs and obtain a better product from the point of view of aesthetic and functional view; the use of such a technology, conceptually known for the production of these tubes, has not been used with simplicity so far because of the various disadvantages that, on the contrary, with the present invention are overcome. Having described the present invention, it is considered as a novelty and therefore what is described in the following claims is claimed as property.

Claims

NOVELTY OF THE INVENTION CLAIMS

1 - . 1 - A tube (1) of a single piece obtained by injection of plastic material, of the type comprising a lower part (1a) open for the introduction of a product and that can be closed after said introduction, and an upper part ( 1b) provided with a through hole (2) for the exit of the product from the tube, characterized in that the lower part (1a) of the tube (1) is delimited by a side surface having a thickness less than that of the lateral surface that delimits the remaining part of the tube. 2. The tube according to claim 1, further characterized in that the lateral surface of lower thickness has a height, starting from the lower end of the tube, which is variable, in relation to the total dimensions of the tube, from a few millimeters up to 1-2 centimeters and represents approximately one tenth of the total height of the tube. 3 - The tube according to claim 1, further characterized in that the side surface of lower thickness has a thickness comprised between 0.40 and 0.55 millimeters. 4. The tube according to claim 1, further characterized in that the reduction of the thickness of the lateral surface of the lower zone of the tube is obtained by keeping the outer diameter of the tube unchanged and increasing the internal diameter of the same tube. 5. - The tube according to claim 1, further characterized in that the upper part (b) of the tube comprises an opening (3) of dimensions greater than the dimensions of the through hole (2) and is arranged in the area of said upper part in which it is desired to obtain said through hole; it comprises a reducing element (4), on which said through hole (2) is obtained, shaped and arranged so as to be sealed, hermetically, in said opening (3). 6. - The tube according to claim 5, further characterized in that said opening (3) has a circular section and is obtained on a plane perpendicular to the axis of the tube; said reducing element (4) comprises an outer ring (4a) able to fit in said opening (3); the through hole (2) is obtained concentric to the outer ring (4a).