Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
  • B65B31/00—Packaging articles or materials under special atmospheric or gaseous conditions; Adding propellants to aerosol containers
  • B65B31/02—Filling, closing, or filling and closing, containers or wrappers in chambers maintained under vacuum or superatmospheric pressure or containing a special atmosphere, e.g. of inert gas
  • B65B31/021—Filling, closing, or filling and closing, containers or wrappers in chambers maintained under vacuum or superatmospheric pressure or containing a special atmosphere, e.g. of inert gas the containers or wrappers being interconnected

Definitions

• the invention relates to a method for packaging articles, in which a film trough is formed from a film, the object to be packaged is introduced into the film trough, the film trough is brought with a cover, the pressure inside the film trough and in which "the film trough" is lowered on its underside surrounding outer space and the film trough is sealed to the cover by welding or sealing, and the invention also relates to a device for carrying out this method.
• 26 41 160 is used in particular for the packaging of objects such as food, the shelf life of which can be extended by evacuation. at usually both the interior and the exterior space of the film trough is evacuated simultaneously until the end vacuum required for durability is reached. This final pressure is relatively high with an absolute pressure of approx. 5 to 10 mbar If products such as cheese, for example, are to be packed using this process that are finely divided or contain gases in bubbles, this evacuation can lead to expansion.
• the object of the invention is to improve a method of the type described above and the associated device. In particular, the expansion of the bubbles or liquid in the product to be packaged is to be avoided.
• a method of the type described at the outset which, according to the invention, is characterized in that, when a first predetermined pressure is reached, pressure difference between the pressure in the interior and the pressure in the exterior is generated, in such a way that the film trough under egg effect the pressure difference is pressed against the object.
• the device is characterized in that the control unit is designed in such a way that, when a predetermined pressure value in the lower chamber is reached, it controls the valves so that the pressure in the lower chamber rises and the evacuation in the upper chamber continues.
• FIG. 1 shows a schematic side view of a packaging machine for the application of the invention
• Fig. 2 is a schematic diagram of a first embodiment of an apparatus with a cut erfihdungswashen ent ⁇ long the line II-II in Fig. 1;
• FIG. 3 shows a schematic diagram of a second embodiment of a device according to the invention with a section along line II-II in FIG. 1;
• FIG. 4 shows a diagram of the pressure curve according to the invention in the interior (dashed line) and in the exterior (solid line).
• FIG. 1 schematically shows a side view of a vacuum packaging machine 1 according to the invention with a molding station 2, a filling station 3 and an evacuation and sealing station 4.
• a material web 5 is drawn off from a supply roll 6 and successively through the shape.
• Station 2 the filling station 3 and the evacuation and sealing station 4 moves.
• troughs 7 for receiving objects are formed in the material web, into which the goods to be packed are introduced in the filling station 3.
• a second material web 8 is guided as a cover over the troughs and welded or sealed to form a closed package.
• the evacuating and sealing station 4 has an upper tool 9 and a lower tool 10.
• the upper tool 9 On the side facing the lower tool 10, the upper tool 9 has an upper chamber 11 which forms a recess and in which a heated sealing plate 12 with a heating element 13 is arranged.
• the Lower tool 10 is designed as a container open to upper tool 9, the side walls 14, 15, 16 of which enclose a lower chamber 17.
• a transport device 18, 19 is arranged on both sides, which material web 5 with the trough 7 and one in the trough
• the lower tool 10 can be moved up and down in the direction of the double arrow 21.
• the second material web is over the trough 7
• the upper chamber 11 can be connected to a vacuum pump 24 via a first connecting line 22 and the lower chamber 17 via a second connecting line 23.
• Each of the connecting lines 22, 23 has a shut-off valve 25, 26 and in the areas 27, 28 of the connecting lines 22, 23 between the chambers 11, 17 and the shut-off valves 25, 26 one shut off by means of ventilation valves 29, 30 ⁇ bare branch 31, 32 to the atmosphere.
• the valves 25, 26 and 29, 30 are each designed as solenoid valves and with outputs 33, 34; 35, 36 of a controller 37 connected.
• a contact vacuum gauge ⁇ imaginary manometer 38, 39 are provided, whose outputs are connected to inputs 40, 41 of the controller are connected 37th
• the manometer 38 has at least one and the manometer 39 have at least two adjustable switching points which are set in a manner to be described later.
• the trough 7 is filled with the goods or object 20 to be packed, the lower tool 1 is lowered and the trough 7 with the object 20 by means of the transport device 18, 19 under the upper tool 9 into that shown in FIG. 2 Position moved.
• the lower tool 10 then moves upwards and the trough 7 enters the lower chamber 17.
• the second material web 8 is introduced into the evacuation and sealing station 1 and, together with the trough 7, delimits an interior space 42 which contains the object 20.
• the interior 42 communicates with the upper chamber 11 through the distances between the side walls of the upper tool 9 and the side edges of the second material web 8 or the sealing plate 12, while the outer space present between the lower tool 10 and the trough 7 43, which surrounds the trough 7 on its outside, is tightly separated from the upper chamber 11 and the interior 42 by the material web 5 or the trough 7.
• the evacuation process now takes place, the pressure curve being shown schematically in FIG. 4.
• the control 37 closes the ventilation valves 29, 30 and opens the shut-off valves 25, 26 at the time t Q.
• the vacuum chamber 24 connects the upper chambers 11 and 11 via the first connecting line 22 the interior 42 connected to it and the exterior 43 evacuated via the second connecting line 23. By connecting the first and second connecting lines, the pressure drop, as shown in FIG. 4, takes place to the same extent.
• the first switching point of the manometer 39 is set to a pressure p, which is preferably of the order of 200 to 800 mbar and, according to a particularly preferred embodiment, is approximately 500 mbar. If the pressure in the interior 42 and in the exterior 43 reaches this first predetermined pressure value at the time point t 1 , then the manometer 39 supplies a signal to the control 37 and the control 37 closes the shut-off valve 26 and opens the ventilation valve 30 Pressure increase in the outer space 43 up to a second predetermined pressure value p 2 , to which the second switching point of the pressure gauge 39 is set and this emits a second signal to the controller 37, which then closes the ventilation valve 30 again, so that the pressure in the outer space remains about constant.
• p which is preferably of the order of 200 to 800 mbar and, according to a particularly preferred embodiment, is approximately 500 mbar.
• shut-off valve 25 remains open and the ventilation valve 29 is closed, so that the interior space 42 is continuously evacuated until a required final pressure of around 5 to 10 mbar is reached by the time t 3 , to which the switching point of the Manometer 38 is set.
• the control 37 closes the shut-off valve 25.
• the two material webs 5, 8 are then sealed to one another and the evacuation and sealing station 4 can be ventilated again.
• a differential pressure .DELTA.p arises between the inner space 42 and Exterior space 43, which presses the trough 7 towards the object 20 and both upwards against the second material web 8 or the sealing plate 12.
• air present between the material web 7 and product 20, product 20 and material web 8 and between 5 material web 5 and material web 8 is pressed out of the trough 7 into the upper chamber 11.
• the force exerted on the product by the differential pressure & p causes the object 20 to be supported or pressed together, thus preventing expansion of the object 20 or
• the differential pressure ⁇ p is determined by
• the choice of the first predetermined pressure value p .. and the second predetermined pressure value p 2 is chosen such that a permissible expansion measure is not exceeded in accordance with the object 20 to be packaged.
• the advantage is achieved that the evacuation to the required final vacuum can take place more quickly since only the inner space 42 and the upper chamber 11 have to be evacuated.
• the differential pressure at time t 1 must be at the first preselected pressure value p. if possible. are formed abruptly or the pressure rise speed when ventilating the outer space 43 is as high as possible, that is to say the time span ⁇ t is chosen to be as small as possible.
• a value of .DELTA.t of the order of magnitude between 100 and 200 msec is considered to be favorable, so that the pressure increase between the first and the second preselected 30 pressure value takes place in a time which is less than a tenth the time required for the evacuation.
• the line cross-sections in the second connecting line 23 between the lower chamber and the ventilation valve 30 are chosen to be as large as possible and a shut-off valve is selected for the ventilation valve 30, which allows a quick opening, for example a flap or Slider valve.
• the lower chamber 17 is connected to a buffer store 45 via a line 44 and a shut-off valve 46 which can be actuated by the control 37 is provided in line 44.
• the buffer store 45 is connected to a pressure source 48 via a further shut-off valve 47.
• a pressure gauge 49 is provided on the buffer store 45, which emits a signal to the controller 37 when a predetermined pressure in the buffer store 45 is reached.
• the pressure in the buffer store 45 is brought to a preselected value by opening the shut-off valve 47 until the preselected value is detected by the manometer 49 and sent to the Control 37 is reported.
• the pressure increase at time t. is then achieved not by opening the ventilation valve 30, but by opening the shut-off valve 46.
• the pressure in the outer space 43 rises almost suddenly due to the immediate pressure compensation between the buffer store 45 and the outer space 43.
• This increase in pressure and the second predetermined pressure value p p is indicated by the choice of the size of the buffer memory 45 and the pressure in the buffer memory 45 affects.
• the pressure equalization can take place faster, the higher the pressure in the buffer store 45 is selected.
• the buffer storage volume must also be selected to be the smaller in order to reach the second predetermined pressure value.
• the buffer storage volume is preferably selected to be smaller than the volume of the sub-chamber 17 and, according to a particularly preferred embodiment, approximately as large as the volume of the outer space 43, that is to say the sub-chamber volume minus the volume of the object or product 20.
• the preset initial pressure in the buffer store 45 before the pressure equalization can practically be chosen between about 0.5 and 3 bar absolute pressure, preferably between 1 and 1.5 bar.
• the buffer store 45 is mounted as close as possible to the lower chamber 17 and is preferably flanged directly to the latter via the valve 46 or only separated from it by a short flexible line piece that allows the displacement of the lower tool 10.
• the process according to the invention thus has the advantage that the air contained in the package to be formed is pressed out or mechanically displaced and the product is supported in the trough in such a way that, depending on the selected one Differential pressure no or only a small expansion of the gas blow or can occur due to evaporation.
• the differential pressure can be formed either by lowering the pressure in the upper chamber or by increasing the pressure in the lower chamber. It is essential, however, that the differential pressure is formed fairly quickly and practically “suddenly" in the form of a "pressure jump".

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• Chemical & Material Sciences (AREA)
• Dispersion Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Vacuum Packaging (AREA)
• Package Closures (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=6232155

Family Applications (1)

Country Status (4)

Cited By (3)

Families Citing this family (6)

Citations (3)

Family Cites Families (4)

• 1984
  • 1984-03-30 DE DE19843411917 patent/DE3411917A1/de active Granted
• 1985
  • 1985-03-29 WO PCT/EP1985/000136 patent/WO1985004379A1/de unknown
  • 1985-03-29 EP EP19850902007 patent/EP0175778A1/de not_active Withdrawn
  • 1985-03-29 JP JP60501787A patent/JPS61501624A/ja active Pending

Patent Citations (3)

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