MXPA06008452A - Container and method for producing such a container - Google Patents

Abstract

The invention relates to a container (1) comprising a mouth opening and a membrane lid (5) arranged with an attachment zone (6) on the edge of the mouth opening for closing the container, wherein the membrane lid consists at the attachment zone (6) over its thickness of plastic. The invention further relates to a method for producing such a container.

Description

CONTAINER AND METHOD FOR THE PRODUCTION OF THE SAME Field of the Invention The invention relates to a container comprising a lower part, a peripheral wall extending from the edge of the lower part, an opening or opening defined by the upper part of the peripheral wall and a closure or membrane cap located with a joining area on the edge of the entry opening for closing the container. Background of the Invention These containers are normally used for the storage of food and other products. The membrane cover is sealed on the edge of the inlet opening. This sealing takes place with a heated tool, which is pressed on the lid, so that the lid and the inlet opening are heated in the joint area and that the lid can melt at the edge of the inlet opening. It is common to provide at least one metallized layer on the side of the lid. Another possibility is to manufacture the lid from a metal membrane. The hot tool transfers the heat, due to the good conductivity of the metal, towards the joint zone, so that the connection of the lid with the container can be effected. There is a trend in which consumers REF.174639 want to observe what is stored inside the container. Therefore, a container needs a window through which the contents of the container can be seen. With metalized membrane or metal caps, this is not possible. In order to provide a window, the membrane cap has to comprise an area consisting of a transparent plastic through which the contents can be observed. However, with the current sealing method, this is not possible. With a plastic, the plastic would adhere to the heating tool with a lid that contains more than one layer the joint would be difficult due to the poor conductivity of the heat, in addition, the lid would often ripple due to the different behavior of the different layers of plastic. From the point of view of the manufacturers it is desired to have a manufacturing process in which batches or series of pieces of different sizes of containers can be filled and sealed easily with a membrane cap without a dead time or substantial stoppage of machinery. When the conventional manufacturing method is used, hot tools have to be exchanged in order to be able to fill and seal another type of container. This means that the operator has to disconnect the machines and physically remove the tools and exchange them with suitable tools for the new batch of containers. SUMMARY OF THE INVENTION An object of the invention is to provide a container, with which the disadvantages mentioned above are met. This objective is achieved by means of a container according to the preamble, which is characterized in that the membrane cover consists of the joining area on its thickness of plastic material. This allows the lid to be joined to the edge of the entry opening by an energy beam, such as a laser beam or an electron beam. With the current cover, which comprises at least one metallized layer, this is not possible, since the metal would reflect the energy beam, so that the energy can not reach the interconnection between the edge of the entrance opening and the cover membrane in order to join the lid with the edge. Since the container according to the invention allows the use of an energy beam, the manufacturing process becomes more flexible, since containers of different shapes and sizes can be handled without a substantial dead time, since only the device that Control the energy beam has to be reprogrammed. This even makes it possible to manufacture containers of all types of shapes, since the reprogramming of the control device can be carried out in each individual container.

With a container according to the invention, hot tools are no longer needed, so that the membrane cover can comprise a window through which the consumer can observe the contents. This container can be made of metal, plastic and combinations thereof. According to one embodiment of the container according to the invention, a central zone surrounded by the joining zone comprises a metal layer. The metal layer on the membrane cap provides a barrier or protection for sunlight and counteracts the diffusion of the compounds through the cap. This prolongs the storage life of the provisions or food contained in the container. In a preferred embodiment of the container according to the invention, the lower part and the peripheral wall are made of metal sheets. In particular, with metal sheet containers the cover according to the invention has its advantages, since this provides a new and more flexible way of manufacturing containers with membrane layers. Still in another embodiment of the container according to the invention, the joining area of the membrane cap is fused at the edge of the inlet opening. Preferably, the edge of the entry opening comprises a plastic. The plastic of the inlet opening will melt with the plastic of the membrane cap providing a gas tight seal. In another embodiment, the edge of the entry opening comprises a plastic coating. This plastic coating is preferred with metal foil containers. The invention also relates to a method for the production of a container having an inlet opening defined by the upper part of the peripheral wall and a membrane cover located with a joining area on the edge of the inlet opening for the closure of the container, wherein the method comprises the steps of: - providing a container with a bottom and a peripheral wall; - providing a first plastic on the edge of the entry opening, defined by the peripheral wall, wherein the first plastic substantially absorbs the energy of a laser beam; - providing a membrane cover having a joining area for coupling with the edge of the entry opening, wherein the joining area of the membrane cover consists of its thickness of a second plastic, which is substantially transparent for the laser beam; - positioning the membrane cap on the edge of the entry opening and guiding the laser beam along and through the joining area on the first plastic, so that the energy of the laser beam is dissipated in the first plastic and the heat generated causes the first plastic and the second plastic to melt. Since a laser beam can be easily programmed to irradiate any type of this contour, this method according to the invention can be used with ease for any type of container shape. In order to transfer the energy of the laser beam into heat, the first plastic is chosen so that it absorbs the energy of the laser beam. This can be achieved by adding an absorbent pigment in the plastic. There are also other types of plastic materials available in the market, which have absorption properties of the laser beam. In order to allow the laser beam to reach the interconnection between the edge of the inlet opening and the membrane cap, the membrane cap itself is made of a transparent plastic for the laser beam, at least in the connecting area, so that the laser beam can pass through the membrane cap and irradiate the first plastic, where the heat is generated in order to melt the first plastic in the second plastic. Preferably, the plastics are thermoplastic. The container can be a metal foil container. Another embodiment of the method according to the invention comprises the step of controlling the dissipation of energy along the junction zone. If the dissipation of energy along the junction zone is controlled, the heat generated is controlled, which makes it possible to adjust the resistance of the lid seal on the edge of the inlet opening. In this way, the force necessary to detach or tear the membrane cap from the inlet opening can be controlled. In this way, it is possible to provide a lid that can be opened with a constant tearing force, despite the shape of the inlet opening. It is also possible to provide part of the joint area with an increase in tearing force, so that the consumer is forced to leave the membrane cap on the container. In a preferred embodiment of the method according to the invention, the dissipation is controlled if the contact time between the laser beam and the membrane cap is regulated. By having the laser beam with a substantially constant power, the energy dissipation is controlled by regulating the contact time of the laser beam in a specific place or area. As the contact time is increased, the dissipated energy is increased providing a stronger bond between the membrane cap and the edge of the entry opening. In yet another embodiment of the method according to the invention, the method comprises the step of guiding the laser beam along the contours of the junction zone and the control of the speed of movement of the laser beam in order to provide melting areas of different dimensions and strength. By controlling the speed of movement of the laser beam, the contact time is also regulated, therefore, the control of the dissipation of energy along the "bonding zone" is provided.Another possibility is to provide a first plastic on the inlet opening having irregular properties along the junction area for the absorption of the energy of a laser beam, in this way, the laser beam can be guided along the joining area to a constant velocity, while the melting areas of different dimensions and strength are still provided In another embodiment of the method according to the invention, the dissipation is controlled by regulating the focus of the laser beam.When the energy of the laser beam is distributed on a place of variable size, the melting areas along the joining zone can be varied In accordance with the method according to the invention, the dissipation It can also be controlled by adjusting the absorption properties of the first plastic. By varying the absorption properties along the bonding zone, for example, by changing the absorption pigment in the plastic, it is possible to create melting areas of different dimensions using a laser beam of constant energy. It is also possible to control the dissipation by regulating the intensity characteristics of the laser beam. This can be effected, for example, by filtering the laser beam for the different parts along the joining zone. Another way to control the dissipation is by varying the transmission property of the membrane layers. BRIEF DESCRIPTION OF THE FIGURES These and other advantages of the invention are clarified in conjunction with the accompanying figures. Figure 1 shows a perspective view of a container according to the invention, Figure 2 shows a cross-sectional view of the upper part of the container according to Figure 1, Figure 3 shows an enlarged detail of the view in cross section of Figure 2, Figure 4 shows a top view of the container according to Figure 1, and Figure 5 shows a cross-sectional view of another container of the invention. Detailed Description of the Invention Figure 1 shows a container 1 according to the invention having a lower part 2, a vertical peripheral wall 3. The vertical wall 3 continues in a ring 4, which could be an integral part of the wall vertical 3. The ring 4 defines an inlet opening on which the membrane cover 5 is located. The cover of "membrane 5 is placed with a joining area 6 on the edge of the ring 4. Figure 2 shows a view in cross section of Figure 1. In this Figure 2, the inlet opening 7 is shown, which is defined by the ring 4. The membrane cover 5 is located on the edge of the ring 4 with a joining area 6. Figure 3 shows a detail of the Figure 2. The ring four has a raised portion 8 and ends in a curl or ripple 9, which avoids the sharp edges of the inlet opening 7. On the raised part 8, a lining 10 of a first plastic is located. This first plastic absorbs the energy of a laser beam B and transfers the energy into heat. On top of the liner 10, the membrane cover 5 is placed, which consists of a second layer of plastic 11 which is transparent to the laser beam B and the metal layer 12, which blocks the dissipation of the compounds of food and blocks sunlight. When the container 1 is manufactured, the liner 10 is applied to the ring 4 and the membrane cover 5 is placed on top of the inlet opening 7. Then, a laser beam B is guided along the junction zone 6. The energy of the laser beam B is absorbed by the first plastic 10, so that the heat is generated and the plastic coating 10 melts with the plastic layer 11 of the membrane cover 5. ~ Now observing Figure 4 shows a top view of the container 1. The membrane cover 5 is provided with a tongue 13 so as to be able to tear off the membrane cover 5. With a dashed line the melting area 14 is shown. If controlling, for example, the speed of the laser it is possible to provide larger areas of fusion 15 and smaller areas of fusion 16. In order to detach or tear off the membrane cap of the larger fusion areas 15, it is necessary one more force g tearing range that in the smaller melting areas 16. This provides the possibility of adjusting the tearing force that is necessary to pull the membrane cap 5 of the container 1. Any of the desired properties can be provided. Figure 5 shows another plastic container 17 of the invention. This comprises a plastic bottom part 18 with an integral ring 19. The ring 19 is provided with a plastic coating 10 absorbing the laser energy on which the second transparent plastic laser layer 11 is present. This layer 11 carries the sheet thin metal 12.

It is noted that in relation to this date the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (9)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A "container is constituted by an inlet opening and a membrane cover located with a joining area on the edge of the entry opening for the closure of the container, the membrane cover consists of the joining area on its thickness of plastic material, wherein a central zone surrounded by the joining zone includes a metal layer, wherein the lower part and the peripheral wall are metal foil, characterized in that the edge of the inlet opening comprises a plastic coating and the joining area of the membrane cover is fused at the edge of the inlet opening 2. A method for the production of a foil container metal having an entrance opening defined by the upper part of the peripheral wall and a membrane cover located with a joining area on the edge of the opening d and inlet for closing the container, characterized in that it comprises the steps of: - providing a metal sheet container with a lower part and a peripheral wall; - providing a first plastic coating on the edge of the inlet opening, defined by the peripheral wall, wherein the first plastic substantially absorbs the energy of a laser beam; - providing a membrane cover having a joining area for coupling with the edge of the entry opening, wherein the joining area of the membrane cover consists of its thickness of a second plastic, which is substantially transparent for the laser beam; - positioning the membrane cap on the edge of the entry opening and guiding the laser beam along and through the joining area on the first plastic, so that the energy of the laser beam is dissipated in the first plastic and the heat generated causes the first plastic and the second plastic to melt. 3. The method according to claim 2, characterized in that it comprises the step of controlling the dissipation of energy along the joining zone. . The method according to claim 3, characterized in that the dissipation is controlled if the contact time between the laser beam and the membrane cap is regulated. The method according to claim 3 or 4, characterized in that it comprises the step of guiding the laser beam along the contours of the joining zone and the control of the speed of movement of the laser beam in order to to provide fusion areas of different dimensions. 6. The method according to any of claims 3-5, characterized in that the dissipation is controlled if the focus of the laser beam is regulated. The method according to any of claims 3-6, characterized in that the dissipation is controlled if the absorption property of the first plastic is adjusted. The method according to any of claims 3-7, characterized in that the dissipation is controlled if the transmission property of the membrane layers is adjusted. The method according to any of claims 3-8, characterized in that the dissipation is controlled if the intensity characteristic of the laser beam is regulated.