MXPA97002730A - Procedure for formation of a plastic container and its cover, in a single step of pressure blowing, and the mold used in mi - Google Patents

Abstract

The present invention relates to a method of forming a plastic container and its lid, in a single step of pressurized blowing, wherein the forming mold used in the process includes an appendix located in its upper portion and which also corresponds to the upper portion of the main body of the container. The appendix esparte integral of the same mold and adopts the form and dimensions required to function as lid of the enva

Description

"PROCEDURE FOR FORMATION OF A PLASTIC PACK AND ITS COVER, IN A SINGLE BLOCK POSITION, AND THE MOLD USED IN IT" FIELD OF THE INVENTION The present invention relates to the technique for the manufacture of containers or containers within the plastics industry, and piaß is particularly related to a process of forming a plastic container and its lid, in a single step of blowing to pressure, and the mold used in it.

BACKGROUND OF THE INVENTION For many years, containers or containers that serve to contain fluids or bulk materials have been known, which currently have a number of shapes and types, being manufactured in various materials, such as glass, metal, plastic materials, etc., where the shape and size, as well as the manufacturing material, are depending on what you want to contain in them. Also, various methods for the manufacture of containers are known, within which there are the methods of forming by blowing both plastic and glass.

The pressure-blow forming process currently used for the manufacture of plastic containers basically comprises a first stage of preparation of the blowing machine, incorporating a mold that has the shape of the product to be produced, to later load the material in bulk in the hopper of feeding and submit the material to a stage of warming, which takes place inside and all along the barrel of the machine of blowing, maintaining a temperature that goes from 140"C up to 250 ° C depending on the material to blow in. In a next step, the molted polymecop material is injected in the form of a pipeline section into the cold mold, then pressurized air into the interior of said section of material pipeline. polirnepco, said air being injected at a pressure that goes from 6 to 10 I 'g / cm2 depending on the material to be worked, until the polymeric material adopts the fo of the mold, thus obtaining the main body of the container, finally, once said package has cooled, undergo a cutting and refining operation, in order to remove the waste material to the main body of the container , which is discarded. The process of formation by pressure blowing using plastic materials has had a great industrial application, being used over the process of formation by glass blowing, due to the advantages it provides for being a low cost process, together with the fact of that a wide range of thermoplastic polymeric materials can be used, such as polypropylene, high and / or low density polyethylene, polystyrene, polyvinyl chloride (PVC), polyethylene terephthalate (PET), combinations thereof, or , any other thermoplastic polymer. However, there is currently the drawback that in none of the plastic packaging manufacturing processes is it possible to obtain both the plastic container and its corresponding lid at the same time, requiring two different procedures to obtain the container on one side. and on the other hand the lid that will serve to close said container, which implies that the manufacturing costs of the final product are increased. As a consequence of the above, it has been sought to eliminate the drawbacks of the current packaging manufacturing processes, and to provide a process for forming a plastic container and its lid, in a single step of pressure blowing, which besides eliminating disadvantages previously established, offer the possibility of obtaining an economic, practical and functional product.

OBJECTS OF THE INVENTION Taking into account the defects of the prior art, it is an object of the present invention to provide a method of forming a plastic container and its lid, in a single step of blowing under pressure, which is simple, practical and economical, and yet high efficiency for the manufacture of a container and its corresponding lid at the same time. It is a further object of the present invention to provide a method of forming a plastic container and its lid, in a single step of blown under pressure, which allows obtaining a final product of excellent quality, without detriment to its physical and chemical properties . It is a further object of the present invention to provide a method of forming a plastic container and its lid, using a mold of special design, which allows the manufacture of both the main body of the container, as well as its corresponding lid in a just happened. The above objects, as well as other objects and advantages of the invention, are achieved by means of a pressure-blow forming process comprising the steps of preparing the blowing machine, incorporating a forming mold having the shape of the product that is will produce, to later load the material in bulk in the feed hopper and subject the material to a heating stage, which is carried out inside and along the length of the cannon of the blowing machine, in a next stage it injects the molten polymeric material in the form of a pipeline section into the cold mold, and then blows pressurized air into said section of pipe of polimecop material until the polyimepco material assumes the shape of the mold, thereby obtaining the Main body of the container, for finally, once said formed container has cooled, undergo a cutting and refining operation, wherein the mold The forming part includes an appendix located in its upper portion and which also corresponds to the upper portion of the main body of the container, said appendix being an integral part of the same mold and adopting the shape and dimensions required to function as the lid of the container.

DETAILED DESCRIPTION In the pressure-blow forming process of the present invention, it has been possible to obtain in a single blowing step, a plastic container and its corresponding cover, using a conventional blowing machine to which a mold has been incorporated. special design, which presents the shape of the container that it is desired to produce, in addition to including an appendix located in the upper portion of the mold, which corresponds to the lid of said container.

As already mentioned in the previous art chapter, the pressure-blow molding process currently used for the manufacture of plastic containers, basically comprises a first stage of preparation of the blowing machine, incorporating a forming mold having the shape of the product to be produced, to later load the material in bulk, in the feed hopper and submit the material to a heating stage, which is carried out inside and all along the barrel of the blowing machine, maintaining a temperature that goes from 140 ° C to 250 ° C depending on the material to be blown. In a next stage, the molten polymer material is injected in the form of a pipeline section into the cold mold, and then, pressurized air is blown into said section of polymer material duct, said air being injected at a pressure that it goes from 6 to 10 kg / cm2 depending on the material to be worked, until the polymeric material adopts the shape of the mold, thus obtaining the main body of the container, for finally, once the formed container has cooled , undergo a cutting and refining operation, in order to remove the waste material, which is usually the extreme portion of the upper part of the container, which is discarded. The innovative methodology of the present invention basically comprises not discarding the end portion that is separated from the main body of the container, but rather taking advantage of it as the lid of the same container, for which it is necessary to incorporate an appendix that allows the formation of an extreme piece that is reused as the lid of said container, for which, as already mentioned, it is required to modify the blow mold. It is important to mention that the mold is designed to include both the body of the container and its corresponding lid, which allows the possibility of obtaining in a single step of blowing, a practical and functional product. The modification to the blow mold consists in adding an appendix located in the upper portion of the mold and which also corresponds to the upper portion of the container; said appendix being an integral part of the same mold and adopting the shape and dimensions required to function as the lid of the container. The special design mold comprises a hollow main section that gives the shape of the main body of the container to be produced; and, an appendix in the upper end portion of said hollow main section, which forms an integral part thereof. It is important to mention that the appendix is also hollow and adopts the form and dimensions required to function as the lid of the container to be produced; wherefore, once the process of forming the container has been carried out, said appendix is separated from the main body and reused as the cap of the ism.

The use of the mold of special design in the pressure-blown process of the present invention, allows that in a single manufacturing step, the main body of the container is obtained at the same time as its corresponding lid, thereby eliminating the additional procedure of manufacture of the lid, since at present, the container and its lid are obtained in two separate procedures. During the forming process, the appendage of the mold allows an additional end portion to be formed, which is subsequently cut out and used as the lid of the container. The polymeric material that is employed in the pressure-blow forming process of the present invention, is selected from a wide range of thermoplastic polymeric materials such as polypropylene, high and / or low density polyethylene, polystyrene, polyvinyl chloride (PVC), polyethylene terephthalate (PET), combinations thereof, or any other another pure and / or pigmented thermoplastic polymer. The pressure-blow forming process of the present invention will be more clearly illustrated by means of the following example, which is presented solely for illustrative and non-limiting purposes.

EXAMPLE For purposes of exemplifying the novel features of the pressure-blow forming process of the present invention, a package was made using a conventional plastic blowing machine. The machine was prepared by placing the mold of special design that has the shape of the container to be produced, in addition to including an appendix that will shape the lid. Subsequently, the bulk material was loaded in the feed hopper. The material used in the present example was polypropylene. Once the material was loaded, the operation was carried out by blowing, where the material was passed along the length of the machine's barrel, maintaining a temperature between 15 ° C and 160 ° 0. Next, air at a pressure of 7 kg / cm2 was injected into the pipeline section in a cylindrical and hollow form that is formed as part of the process and inside the mold, until the section of duct took the shape of the mold. Finally, the main body of the container of the formed end portion was separated by a cutting operation, which was refined and detailed to be used as a lid of the same container. According to the above description, it can be seen that the procedure in question has been devised so that by modifying the pressure blow mold, as well as the reuse of the end portion that is cut, a practical and functional solution is offered to the problems that have to be able to manufacture containers and their respective covers in a single procedure, besides offering a practical and economic product. Although certain embodiments of the invention have been illustrated and described, it should be emphasized that numerous modifications to them are possible. The present invention, therefore, should not be considered as restricted, except for what is required by the prior art and by the spirit of the appended claims.

Claims (4)

NOVELTY OF THE INVENTION CLAIMS

1. - A method of forming a plastic container and its lid, in a single step of blow-by-pressure comprising the steps preparation of the blowing machine, incorporating a form mold that has the shape of the product to be produced, to later load the material in bulk in the hopper of feeding and subject the material to a stage of warming, which takes place inside and all along the barrel of the machine of blowing, in a next stage the polymeric material is injected molten in the form of a pipeline section inside the cold mold, to then blow pressurized air into said section of polymeric material duct, until the polymeric material adopts the mold mold, thus obtaining the body of the container, finally, once said package has cooled, undergo a cutting and refining operation, characterized in that the forming mold includes a n appendix located in its upper portion and which also corresponds to the upper portion of the main body of the container, said appendix being an integral part of the same mold and adopting the shape and dimensions required to function as the lid of the container.

2. A method of forming a plastic container and its lid, in a single step of pressure-blown, according to claim 1, further characterized in that once the package and its appendix has been formed, said appendix it undergoes a cutting and refining operation to separate it from the main body of the container and use it as a lid thereof.

3. A forming mold for use in a method of forming a plastic container and its lid, in a single step of blow-by-pressure, characterized in that it comprises a hollow main section that gives the shape of the main body of the. container to produce; and, an appendix in the upper end portion of said hollow main section, forming an integral part thereof, which is also hollow and adopts the shape and dimensions required to function as the lid of the container to be produced.

4. A mold to be used in a process for forming a plastic container and its lid, in a single step of pressure-blown, according to claim 4, further characterized in that once the procedure has been carried out of forming the container, the product formed in the hollow section corresponding to the appendix separates from the main body of the container and is reused as the lid thereof.