RU2408458C2 - Device for moulding, filling and closing foamed-polymer containers - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: proposed device for containers made from, for example polystyrene foam tape, comprises bottom unwinder (1) to unwinds foamed polymer tape (4), tape heating station (3), container thermoforming station (5), container filling zone (6), bottom unwinder (7) to unwind foamed polymer tape intended for closing moulded containers, container closing station (10), tape cutting station (11) and system (12) to feed tape (4) through said stations. Heating station (10) is made up of two elements, aligned in vertical and horizontally displacing. Container thermoforming station (5) is composed of top and bottom mating dies arranged opposite each other. Both dies have through holes to communicate with reduced-pressure source.

EFFECT: simplified design, reliable operation.

5 cl, 14 dwg

Description

FIELD OF TECHNOLOGY

The present invention relates to a device for forming, filling and closing containers obtained from a foam polymer tape, such as a polystyrene foam tape.

The proposed device is designed to continuously receive molded containers from a tape of foamed polymer or similar material, preferably obtained from a roll, for filling the containers with the product for which they are intended, for their tight closure and, ultimately, for the issuance of individual closed containers for sale . The proposed device, in addition, may contain a device for making certain prints on the covering sheet or film of the container, such as packaging date, expiration date, etc.

To this end, the proposed device comprises a lower unwinding device for a roll, a feeding tape of foamed polymer, a heating station for heating this tape, a station for thermoforming a container, a packaging zone, an upper unwinding device, a feeding film for closing containers, a station for closing containers and an end station for cutting off. The device further comprises a pulling system for pulling the tape passing through all the different stations, from the entrance to the heating station to the exit of the station for cutting. Between the thermoforming station and the location of the upper unwinding device and the station for closing containers there is a space that corresponds to the loading zone, operations in which can be performed manually or automatically.

BACKGROUND OF THE INVENTION

The packaging of various products in expanded polystyrene containers is becoming more and more frequent, especially for perishable products, due to the storage conditions that this type of packaging can offer. Typically, containers are received in the form of pallets through molding machines, and they are delivered to the packer, who performs the filling and closing operation of the container. This system has a number of drawbacks, such as the need for the packer to transport and store containers, the need to adapt beverage containers offered by the container manufacturer, the possibility of contaminating the container from manufacture to filling and closing, etc.

To address these shortcomings, the PCT application published in the international patent document WO 2005/030471 describes a device that allows continuous molding of a container from a foam polymer tape, filling the container and closing and dispensing it for sale.

The device comprises a unit of shafts made as the basis for the roll, an unwinding unit for unwinding the foamed polymer tape, a heating unit for heating the tape, a forming unit in which containers are formed, a closing and sealing unit for closing and sealing containers a printing unit, a unit for cutting in length and a unit for transverse cutting. The device is equipped with a pulling system for pulling the tape, which stops the forward movement of the specified tape during various operations in various nodes and carries out its forward movement at the end of these operations.

Although this device enables the production of containers, their filling and closing, and all this is carried out continuously, it has some drawbacks, mainly in the creation and operation of a heating station, a thermoforming station and a container closing station.

The heating station does not allow for the appropriate adjustment of the heating temperature in accordance with the speed or intensity of the tape along various stations.

In a thermoforming station, there is a risk of unwanted deformations occurring in the container wall.

As for the sealing station, it should be noted that with the method by which this operation is performed, after creating an inert atmosphere inside the container, there is no guarantee of the safety of the placed product.

With respect to cutting stations, it should be noted that, since two cutting stations, a longitudinal cutting station and another transverse cutting station, are arranged in series, this length of the device increases its cost.

SUMMARY OF THE INVENTION

The purpose of the present invention is to eliminate the above disadvantages using a device of the specified type, with a simpler design that provides more reliable operation.

In the device made in accordance with the invention, the heating station is designed so that it allows for proper temperature control both due to the number of radiating elements and by changing the distance of these elements from the tape being molded.

On the other hand, the thermoforming station provides perfect adaptability of the tape to the surfaces of the mold and the reciprocal form, forming part of this station, so that the risk of unwanted deformations is eliminated.

The conditions of food safety are ensured by creating an inert atmosphere inside the container, and this operation is carried out in a simple way in a sealing station.

Another advantage of the proposed device is that the general cutting of the tape for preparing already closed containers is carried out in a single cutting station and in one operation.

As indicated, a device made in accordance with the invention is of a type comprising a lower unwinding device for a roll of foamed polymer tape, a heating station for heating the tape, a container thermoforming station, an upper unwinding device for a roll of closing film designed to close the finished molded containers, a closing station designed to close containers, a cutting station and a pulling system moving the polymer tape through personal station retaining strap is stopped during the execution of the corresponding operation in each station, each time after these operations resulting in movement of the tape and move it forward in succession through the various stations. To this end, various drive elements, both the pulling chain and the chain for actuating the moving elements of various stations and unwinding devices, are coordinated using an appropriate control program, and all this is carried out in a known manner.

In accordance with the present invention, the heating station is formed by two vertically aligned horizontal displaceable elements, one of which is located above the pulling system and the other below it, and both displaceable elements are mounted on the same structure with the possibility of vertical movement on it by means of drive cylinders, for bringing them closer to each other or removing them from each other. These movable elements are equipped with heating devices located on their opposite surfaces. In this station, the tape is heated without contact with it, which is performed as a stage preceding the formation of the containers. The heating device is preferably formed by resistance elements designed to create infrared radiation and located on reflective surfaces. The heating temperature can be adjusted appropriately by changing the number of activated resistance elements and by changing the distance between the displaceable elements.

Directly in front of the heating station there is a table for centering the polymer tape, on which the tape coming from the lower unwinding device is laid, and along which it is brought to the pulling system. The table at its longitudinal edges has movement limiters arranged to move in the transverse direction; on these stops, for the longitudinal centering of the tape, its longitudinal edges are supported.

In a device made in accordance with the invention, the thermoforming station is formed by a lower shape and an upper response form, located opposite each other and mounted on platforms made with the possibility of movement in the vertical direction. Both the mold and the reciprocal mold have through holes between their outer and inner surfaces. Through these openings, the mold and the response mold are connected to a source of reduced pressure, which during the molding operation creates a reduced pressure between the tape that is being molded and the surfaces of the mold and the response mold. Thus, the full attachment and adhesion of the tape to the surfaces of the mold and the reciprocal shape is ensured, thereby preventing the risk of deformation. In this operation, the container is usually obtained in the form of a pallet. Behind this station there is a loading or packing area designed to place the product in pallets or containers, while this operation can be performed manually or automatically. Behind the loading zone, there is a station for closing containers, which contains a lower mold, the geometric shape of which coincides with the shape of the finished molded containers, and an upper brewing plate, said mold and plate being movable in the vertical direction by means of drive cylinders. A polymer tape with molded containers filled with the product and a closing film coming from the upper unwinding device are stacked on top of each other between the mold and the plate. This station has a device for creating reduced pressure inside the containers and for filling them with inert gas with adjustable parameters, ensuring the safety of the product packaged in the container.

Finally, the device includes a cutting station, which is formed by a set of lower frames, the number and location of which each time coincides with the containers reaching this station, and with a circuit that is made the same as the circuit of these containers, and these frames are located directly under the pulling system . In addition, the station contains an upper blade having a contour coinciding with the final contour of each container, and this blade is located above the pulling system and moves in the vertical direction by means of a drive cylinder. The cutting station is equipped with two or more suction cups designed to hold the containers. Suction cups are located upside down above the containers and suspended on the rods so that they cross in the vertical direction the contour bounded by each blade. The cutting station comprises a conveyor belt located under the entire assembly described, moreover, this conveyor belt is responsible for receiving containers that are already separated from the belt.

Suction cups can be moved vertically between the upper position located above the containers and the lower position in which containers are transported vertically and stacked on a conveyor belt.

The upper unwinding device contains a sensor for the passage of the film or its advance and a braking device for braking the specified film, which can be activated by the passage sensor and ensures proper placement of the film on the molded containers to be closed.

A device for creating a reduced pressure in containers and filling them with an inert gas with adjustable parameters in the station for closing containers contains a lid covering the upper brewing plate and configured to move in the vertical direction between the upper, inactive position in which it is separated from the mold and the lower the position in which it rests on the mold and hermetically closes such a mold when said mold is in its upper position. The lid can be connected to a source of reduced pressure and to an inert gas supply source with adjustable parameters, allowing the container to be subjected to these two situations in a row, in the first of which all contaminated air contained in the container is removed, after which gas with adjustable parameters is injected there, after whereby the upper brewing plate is lowered, squeezing the sections of the tape surrounded by the empty space of the container and the upper covering film between the specified plate and the mold until sealing both components.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of all the distinguishing features set forth, as well as other characteristics of the invention, a description is made below with reference to the accompanying drawings, in which a non-limiting embodiment is illustrated.

The drawings show the following:

Figure 1 depicts a schematic side view of a device made in accordance with the invention;

Figure 2 is a perspective view of a lower unwinding device for a roll of foamed polymer tape;

Figure 3 is a perspective view of a table for centering a polymer tape;

Figure 4 is a perspective view of a heating station for heating the tape;

5 is a vertical section of a station for thermoforming a container;

6 is a schematic side view of the upper unwinding device for a roll of film intended for closing containers;

7 is a perspective view of a shaft of an upper unwinding device;

Fig. 8 is a schematic cross-sectional view of a shaft of an upper unwinding device taken along line VII-VII of Fig. 7;

Fig.9 is a vertical longitudinal section of a container closure station;

Figure 10 is a perspective view of a portion of the tape at the outlet of the container closure station with molded and closed containers shown in Figure 9;

11 is a vertical section of a station for cutting;

12 is a schematic view of a pulling system for pulling a foam tape;

FIG. 13 is a vertical section through a pulling system taken along line XIII-XIII of FIG. 12;

Fig. 14 is a diagram of a trajectory of the passage of a pull chain for pulling a tape of foamed polymer.

DETAILED DESCRIPTION OF THE EMBODIMENT

Figure 1 depicts a schematic side view of the proposed device, which contains the bottom unwinding device 1 for a roll of 2 foamed polymer, for example a roll of expanded polystyrene, a heating station 3 for heating the tape 4 made of foamed polymer, station 5 for thermoforming containers, loading zone 6 for loading molded containers , unwinding device 7 for roll 8 of film 9 for closing molded containers, station 10 for closing containers, station 11 for cutting containers and pulls ayuschuyu system 12 for pulling the polymer tape 4 through all the stations, from the inlet station 3 in the heated before leaving the station 11 for cutting.

Figure 2 depicts a lower unwinding device containing a frame 13, on which a shaft 14 is installed, made as the basis for the roll, the unwinding engine 15 and the rocker 16, which regulate the process of unwinding.

The shaft 14 contains two cones 17 designed to center and hold the roll.

The unwinding system is essentially formed by two elements: an engine 15, which drives the shaft 14, and a beam, which provides tension for the unwound tape. The unwinding of the tape occurs with periodic breaks, as necessary for operations performed throughout the device.

When the tape 4 is unwound, it passes through the entrance of the device where the table 18 is located, designed to center the specified tape. This table at its longitudinal edges has movable movement limiters 19 for centering the belt. When the tape passes through this table 18, it is fixed by the chain of the pulling system 12, which has links with upper pointed protrusions piercing the tape in order to pull it, as described below. At table 18, the device comprises a heating station 3, which, as can be seen in FIG. 4, is formed by two displaceable elements, the upper element 20 and the lower element 21, mounted on the structure 22 with the possibility of vertical movement on it by means of drive cylinders 23. The displaceable element 20 is located above the pulling system 12, and the element 21 is located below it. Elements 20 and 21 have reflective internal surfaces, and a variable number of infrared radiation elements 24 is installed in them in accordance with the advance step and the width of the material to be thermoformed. By means of the cylinders 23, the displaceable elements 20 and 21 can be brought closer to each other or retracted to a greater distance, in order to prevent overheating of the material and its damage when the device may stop. In this station, due to the temperature reached between the elements 20 and 21, during the normal operation phase, sterilization of the material is achieved, which may be contaminated due to various reasons.

In the device shown in FIG. 1, a station 5 for thermoforming containers is located behind the heating station 3, and this station 5 for thermoforming, as best seen in FIG. 5, is formed by a lower mold 26 and an upper mating mold 27, which are opposite to each other. The image in FIG. 5 corresponds to a section, which in the described example includes three transversely aligned forms 26 and the same number of response forms 27, intended for thermoforming the same number of containers. Form 26 and the response form 27 are mounted on vertically movable platforms, of which only the platform 28 is shown supporting the response form 27, which can be driven by a pneumatic cylinder 29.

Both mold 26 and mating mold 27 have through holes 30 in communication with a circuit through which pressure can be reduced. An assembly 31 is shown on the upper platform 28, which can be connected to a source of reduced pressure to create a reduced pressure between the forming tape 4 and the surface of the response mold 27, having a geometric shape identical to shape 26. In station 5, the container is molded, for which it rises a mold 26 in the form of a pallet or container to be obtained. This lifting movement of the mold 26 is carried out by a known mechanism, in the same way, since the response mold 27 has a push mechanism driven by the cylinder 29, while the response molds 27 have a geometric shape corresponding to the inner shape of the container.

The formation of the tape 4 to obtain pallets or containers is achieved by bringing the form and the reciprocal form closer to each other and creating reduced pressure. After these operations, the finished molded containers pass along zone 6, where the product to be packaged is laid, and, as soon as the containers, still pulled by the chain, are filled and reach the sealing station 10, in front of which there is an upper unwinding device 7, made as a carrier for roll 8, in which the film 9 is wound, the film closes the containers. Figure 6 shows this upper unwinding device 7, comprising a series of rollers 32 for guiding the film 9, a tension roller 33, a brake 34, which delays the film 9 to stop its forward movement, and a sensor 35 for sensing sections or characters on the film 9, providing prints that the film may have on containers to be closed. 6 depicts a guide device 36 for bringing the film 9 to its entrance to the device to the brewing station 10.

Fig.7 depicts the shaft 37 of the upper unwinding device 7, and the specified shaft has a tubular structure and longitudinal grooves, each of which is a retractable jagged rod 38, which from the inside rests on an inflatable pillow 39 (see Fig. 8), located inside the shaft 37 This shaft at one end has a connector 40 for inflating the cushion 39, while at the other end it is connected to the drive motor 41.

The film 9 is directed inside the station 10, intended for brewing and sealing containers, which is shown in more detail in Fig.9. This station is responsible for welding the film 9 to the contour of the molded containers 42 with the packaged product.

The closure station 10 comprises a lower mold 43, which is sized to accommodate the containers 42, and an upper brewing plate 44. The film 9 and the finished molded containers 42 filled with the product pass so that they overlap, placed between the mold 43 and stove 44.

Before closing the containers, a reduced pressure is first created in them. To this end, the response form 45 is based on the form 43, and the specified response form 45 hermetically closes the specified form. This mating mold 45 has a channel-type opening 46 to which a source of reduced pressure is connected, by which a reduced pressure can be created both inside and outside of the container 42. After that, one or more inert gases with adjustable parameters are injected through the same opening 46, after which the plate 44 is lowered to seal the container. The response form 45 forms a lid tightly closing the form 43, while containers 42 and a film 9 are placed between them. The sealing process is performed without opening or lifting the lid 45 in order to prevent contamination of the gas inside. When the container is sealed, pressure is removed from the lid 45, which occurs until atmospheric pressure is reached, and it opens to allow advancement of the closed containers 42 to the next station 11 for cutting the containers.

Figure 10 depicts a portion of the tape 4 with molded containers 42 and a film 9 located on these containers and hermetically sealed on them.

The cutting station 11, the cross section of which is shown in FIG. 11, is formed by three assembly units, namely: a cutting unit 47, a vertical movement unit 48 for moving the cut containers 49, and an unloading table formed by a conveyor belt 50.

In chronological order, the process begins with the node 48, which is formed by a set of suction cups 51, approaching the lid of the container formed by the film 9, until these containers are captured. In addition, the station contains cutting blades 52 having a contour matching the contour of the cut containers. Suction cups 51 are suspended on rods 53 transversely intersecting the contours formed by the blades 52 to reach the lids of the containers 49.

As soon as the suction cups 51 adhere to the lids of the containers 49, the bottom lining 55, supported by the moving table 56, rises until it rests against the containers. Thereafter, to cut off the containers by means of another upper drive device, the container-shaped plate 57 is lowered carrying the blades 52.

When the containers are cut and given that they are suspended by suction cups 51, the assembly 48 is lowered until the containers 49 are in the vicinity of the conveyor belt 50; at this time, the suction action of the suction cups ceases, and the containers 49 remain located on the belt 50 for unloading them to the outside. Both the lining 55 and the blades 52 and the system for accommodating these elements are returned to their original position, and the pallets can then be unloaded at the side of the device.

After completion of the process, it remains only to remove excess scraps from tape 4 for grinding and reuse.

On Fig-14 shows a pulling system designed to pull the tape 4 of the foamed polymer along various stations. This system comprises two parallel chains running along the guides 59, and these chains are guided on one side by the guide wheels 60 and the drive wheels 61 driven by the motor 62, while on the opposite side they are guided by the guide wheels 63.

As can be seen in FIG. 13, the stretching system comprises a chain 64, the links of which have a pointed protrusion 65 directed upward in the section of the chain advance, while in the section of the rearward movement it is directed downward. This pointed protrusion 65 penetrates and crosses the tape 4 in order to serve as elements for pushing or pulling the specified tape throughout the device.

Claims (5)

1. Device for molding, filling and closing containers of foamed polymer, in particular containers formed from a tape of foamed polymer, such as polystyrene foam tape containing a lower unwinding device for a roll of tape of foamed polymer, a heating station for heating the tape station thermoforming of containers, upper unwinding device for a roll of a closing film designed to close finished molded containers, a station for closing containers , a cutting station and a pulling system designed to pull the tape of foamed polymer along various stations, from the exit of the lower unwinding device to the cutting station, and the heating station is formed by two vertically aligned horizontal displaceable elements, one of which is located above the pulling system, and the other under it, while both movable elements are mounted on the structure with the possibility of vertical movement on it by means of appropriate drive x cylinders to bring them closer to each other or to remove them from each other, while in the indicated displaceable elements on their opposite surfaces heating devices are placed, the thermoforming station is formed by a lower shape and an upper response form, located opposite each other and mounted on vertical movements of the platforms, while the shape and the reciprocal shape have through holes between their outer and inner surfaces, through which they are connected to and creating a source of reduced pressure, creating a reduced pressure between their surfaces and molded ribbon,
the container closure station comprises a lower mold, the shape of which coincides with the shape of the finished molded containers, and an upper brewing plate, both the mold and the plate being movable in the vertical direction by means of drive cylinders, wherein the tape with molded containers filled with the product, and the closing film pass superimposed between each other between the form and the plate, while the specified station for closing has a device for creating a reduced pressure inside the containers and for filling said containers with inert gas with adjustable parameters, and the cutting station comprises: a row of lower frames, the number and arrangement of which each time coincide with the containers reaching this station, and with a circuit that is made the same as the circuit of these containers, wherein said frames are located directly below the pulling system, the upper blade with a contour coinciding with the final circuit of each container, and this blade is located above the pulling system and is made with possibly vertical movement by means of a drive cylinder,
at least two suction cups located above the containers to hold them, while these suction cups are suspended on rods vertically crossing the contour bounded by each blade, and
the conveyor belt located under the indicated frames, while the suction cups are arranged to vertically move between the upper position located above the containers and the lower position in which the containers are held, vertically transported and laid on the conveyor belt. 2. The device according to claim 1, characterized in that at the inlet of the stretching system there is a table designed to center the polymer tape, while the specified tape coming from the lower unwinding device is placed on the specified table, which brings it to the pulling system, and the table on its longitudinal edges it has movement limiters arranged to move in the transverse direction, and on the specified limiters the longitudinal edges of the tape are supported to ensure its longitudinal centering . 3. The device according to claim 1, characterized in that the upper unwinding device intended for the closing film comprises an expandable shaft made as a basis for the roll, a series of guide rollers for guiding the unwound film, a film passage sensor or its forward movement and a brake device for braking said film, which is activated by said passage sensor and which ensures the correct position of the film on molded containers ready for closing . 4. The device according to claim 3, characterized in that said expandable shaft has a tubular structure, has support only at one end, and its wall has one or more longitudinal grooves, through each of which a retractable serrated rod protrudes, which from the inside it relies on an inflatable pillow located inside the shaft, while the shaft at the supported end is connected to the drive motor. 5. The device according to claim 1, characterized in that the device for creating a reduced pressure in the containers and filling them with inert gas with adjustable parameters in the station for closing the containers contains a lid covering the upper brewing plate, and is arranged to move vertically between the upper idle position in which it is separated from the mold and in a lower position in which it rests on the mold and hermetically closes it in the upper position of the mold, wherein said lid is connected to a source nick a reduced pressure and an inert gas supply source with adjustable parameters in order to successively expose these actions container to thereafter be welded to the tape film for containers circuit by lowering the brewing plate.

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