EP0420821A1 - Method for making a vacuum-packing for flowing products, particularly ground coffee - Google Patents

Abstract

The method serves preferably for making a vacuum-packing for ground bean coffee in single-layer packings (10, 113). In a first stage of the method, from stiff yet relatively flexible composite packing materials, printed, folded-flat packing blanks (10) are manufactured, which are pregrooved at the longitudinal edges and near the bottom fold and longitudinally sealed in an overlapping manner and which, before opening of the packing sleeve (10), are shortened, according to a statistically controlled tendency control (49), with a stamp (15) by one packing section to a corrected length of the packing blank (10). In this connection, the tendency control (49) is controlled by the measured values of the filling levels which result after filling and compression of the product in the packings (10). <IMAGE>

Description

The present invention relates to a method according to the preamble of patent claim 1.

• Pos. 1 Vakuum-Einlagenbeutel aus bedruckter, flexibler Verbundfolie, allseitig mit Finseal, d.h. Innen­seite gegen Innenseite gesiegelt;
• Pos. 2 Vakuum-Zweilagenpackung (Doppelbeutel) mit Finseal­gesiegeltem Innenbeutel aus flexibler Verbundfolie, mit verleimtem Ausseneinschlag aus bedrucktem Pa­pier;
• Pos. 3 Vakuum-Packung mit Innenbeutel aus Finseal-gesiegel­ter flexibler Verbundfolie und bedrucktem und ge­rilltem Aussenkarton, allseitig verleimt;
• Pos. 4 Vakuum-Packung, z.B. Ausführung von Ceka, Schweden, mit Innenbeutel aus Finseal-gesiegelter, flexibler Verbundfolie, mit bedrucktem, gerilltem Aussenkar­ton, Längsnaht und Unterseite verleimt, oben Innen­beutel in Kunststoffrahmen zum Oeffnen mit Messer, Wiederverschliessen mit Kunststoff-Stülpdeckel.

The following types of packaging are used today for packaging ground coffee under vacuum:

• Pos. 1 vacuum insert bag made of printed, flexible composite film, with finseal on all sides, ie sealed on the inside against the inside;
• Pos. 2 vacuum two-layer pack (double bag) with finseal-sealed inner bag made of flexible composite film, with glued outer wrap made of printed paper;
• Pos. 3 vacuum pack with inner bag made of finseal-sealed flexible composite film and printed and grooved outer cardboard, glued on all sides;
• Pos. 4 vacuum pack, e.g. version from Ceka, Sweden, with inner bag made of finseal-sealed, flexible composite film, with printed, grooved outer carton, longitudinal seam and underside glued, inner bag in plastic frame at the top for opening with knife, reclosing with plastic slip lid.

For all vacuum packs, the bag surrounding the ground coffee (insert bag or inner bag) must be adapted to the coffee volume that varies during the packaging process. This is usually done by adjusting the package height accordingly.

In all pack versions, the inner cover is made from a very tough composite film that often has to be opened with scissors and a knife.

Opening aids with a tear cut or cut at the top closure can provide relief. However, they have the disadvantage that the crack for opening the pack is not controlled.

In order to avoid this disadvantage, the top closure of the inner bags of the pack versions item 2 and 3 has recently been provided with a tear strip.

This solution also only works reliably if the tear strip is made of a suitable, tough material, the side incisions are carefully placed for the start of the tear and the direction of pull is correctly selected when the thread is torn open.

In addition, the machine device for attaching the tear strip can adversely affect the efficiency and the output of the packaging system. Tear incision and thread make it easier to open the pack.

There is no suitable solution for reclosing the package after partial removal of the ground coffee. Nowadays, the resealing is mostly done by rolling up the top of the bag and storing the package in a can.

When packing according to item 4 with inner bag and outer carton, the outer carton has a plastic frame at the top, within which the inner bag is visible. To open the hard vacuum pack, this inner bag zone must be cut open with a knife. After partial removal of the ground coffee, a plastic cover is placed over the plastic frame to reclose the vacuum pack. Filling this vacuum pack on the The packaging line is on the bottom side. For this purpose, the packaging for filling and closing goes through the packaging system with the plastic frame and lid down.

The package according to item 4 is the only one that offers a reclosable option after a partial removal of the product.

The adaptation to the volume fluctuations of the ground coffee takes place:
- in the vacuum packs according to item 1 or 2 by changing the height of the single or double bag;
- for the packs according to item 3 or 4 through the variable cavity between the inner bag fold and the glued outer cardboard cover flaps. Plastic frame with slip lid.

According to the above, none of the four types of packaging mentioned - combined - guarantees the conditions
- a simple, safe opening without tools (knives or scissors)
- a convenient partial removal and
- easy reclosing;
These are all properties that today's consumers place on modern packaging.

The invention is therefore based on the object of creating a method with which the production of a vacuum pack which, as shown in FIGS. 1 to 4, fulfills the conditions mentioned above. This object is achieved according to the invention by a method having the features specified in the characterizing part of claim 1.

Advantageous embodiments of the invention are specified in further claims. In particular, it was recognized by the invention that great advantages result from the measures mentioned below.

The insert vacuum pack can be produced with printed, grooved and finseal (inside against inside) longitudinally sealed pack blanks made of a rigid composite packaging material.

Alternatively, the composite packaging material can also be removed from the roll in printed and grooved condition. The package height can be adjusted with a tendency control to the volume of ground coffee that varies during the packaging process.

Before the packaging sleeve is formed, the printed, grooved and longitudinally sealed packaging blank or the printed and grooved packaging section removed from the roll can statically regulated and cut to the length corresponding to the package height. The cut is made on the opposite side of the floor scoring.

The packing sleeve is shaped
- in the case of the longitudinally sealed, flatly folded package blank by opening the same and
- With the packaging material removed from the roll, by shaping and longitudinally sealing the packing sleeve on a multi-part, indexing wheel.

For both types of manufacture of the vacuum pack, the intermittently supplied plastic cover with the tear-open tab is sealed on a mandrel molding wheel or molded part and then the pack is inserted with the plastic cover downward into a switchable package cup transport. After being pre-folded, the packs can be filled from the bottom, shaken, measured with a button for the respective fill level, sealed with an expansion fold and partially sealed.

In all of these packaging operations, the packages slide in package cup transport on a floor rail that is adjusted according to the variable filling volume or the package height required for this. The floor rail is adjusted using the fill level button mentioned about a statistical regulation. This statistical regulation, also called trend regulation, also provides the adjustment for the cutting of the packaging material blank to the length corresponding to the package height mentioned at the beginning.

In a subsequent multi-part, continuously rotating chamber wheel, the air is gradually extracted from the packs. These vacuum chambers are also equipped with adjustable base plates, which keep the top fold at a constant level at different pack heights.

After the air has been removed, concave pressing and sealing of the bottom fold can be carried out in the vacuum chambers. After this final sealing and the opening of the vacuum chambers, the packs are returned to the package cup transport, where the folding tips are folded in and sealed on the floor. In this folding part of the packaging system, too, the packs slide on the adjustable bottom rail mentioned above. Due to the concave impression of the bottom fold, the pack is placed on the outer edge and a stable standing is achieved.

• Fig. 1 eine Vakuum-Packung für Mahlkaffee mit Kunststoff­deckel und Aufreisslasche,
• Fig. 2 eine solche Packung beim Oeffnen der Aufreisslasche,
• Fig. 3 eine solche Packung bei der Teilentnahme des Mahl­kaffees,
• Fig. 4 eine solche Packung mit wiederverschlossener Auf­reisslasche,
• Fig. 5 den Aufbau eines Verbund-Packstoffes,
• Fig. 6 den Aufbau einer weiteren Verbund-Packstoff-Variante,
• Fig. 7 einen Stapel mit flach gefalteten, bedruckten, vor­gerillten und längsgesiegelten Packstoff-Zuschnitten,
• Fig. 8 einen geöffneten längsgesiegelten Packstoff-Zu­schnitt (Packungshülse),
• Fig. 9 eine Längsnaht mit auf halbe Packstoffdicke geschäl­tem innerem Nahtteil, der umgelegt Innenseite gegen Innenseite (Finseal) gesiegelt wird,
• Fig. 10 einen Stapel mit flach gefalteten, bedruckten, vor­gerillten und längsgesiegelten Packstoff-Zuschnitten in voller Länge,
• Fig. 11 einen flach gefalteten, längsgesiegelten, um die Höhe ΔH gekürzten Packungszuschnitt und daneben eine geöffnete Packungshülse,
• Fig. 12 eine Packungshülse mit eingesetztem und eingesiegel­tem Kunststoffdeckel mit Aufreisslasche,
• Fig. 13 eine Packung mit Kunststoffdeckel nach unten,
• Fig. 14 eine Packung mit vorgefalteter Bodenfaltung,
• Fig. 15 eine bis zum schraffierten Niveau mit Mahlkaffee gefüllte Packung,
• Fig. 16 eine gerüttelte Packung mit bis zum schraffierten Niveau abgesenktem Füllstand,
• Fig. 17 eine Packung mit gefalteter und teilgesiegelter Bodenfaltung mit Oeffnung zum Evakuieren der Luft,
• Fig. 18 eine Packung mit konkav eingepresster und nach dem Evakuieren der Luft abgesiegelter Bodenfaltung,
• Fig. 19 eine Packung mit eingefalteten und angesiegelten Faltzipfeln,
• Fig. 20 eine fertige Packung mit Kunststoffdeckel und Auf­reisslasche nach oben,
• Fig. 21 den Grundriss eines Kunststoffdeckels mit Aufreiss­lasche,
• Fig. 22 einen Längsschnitt durch den Kunststoffdeckel und die Aufreisslasche,
• Fig. 23 einen Längsschnitt durch den Kunststoffdeckel,
• Fig. 24 einen Querschnitt durch den Kunststoffdeckel und die Aufreisslasche,
• Fig. 25 einen Querschnitt durch den Kunststoffdeckel,
• Fig. 26 ein vergrössertes Detail des Kunststoffdeckels mit Beheizung der Stirnkante des Formraddornes,
• Fig. 27 ein vergrössertes Detail des Kunststoffdeckels mit der Aufreisslasche,
• Fig. 28 den Grundriss eines Kunststoff-Stülpdeckels mit Aufreisslasche,
• Fig. 29 einen Längsschnitt durch den Kunststoff-Stülpdeckel und die Aufreisslasche,
• Fig. 30 einen Längsschnitt durch den Kunststoff-Stülpdeckel,
• Fig. 31 einen Querschnitt durch den Kunststoff-Stülpdeckel mit Aufreisslasche,
• Fig. 32 einen Querschnitt durch den Kunststoff-Stülpdeckel,
• Fig. 33 ein vergrössertes Detail des Kunststoff-Stülpdeckels,
• Fig. 34 ein vergrössertes Detail des Kunststoff-Stülpdeckels mit Aufreisslasche,
• Fig. 35 eine Ansicht der gesamten Verpackungsanlage für die Herstellung der Vakuum-Packungen ab längsgesiegel­tem, flachgefaltetem Packungszuschnitt mit Zuschnitt­stapel, Zuführung der Packungszuschnitte, Formteil, Kunststoffdeckelzuführung, Paketbechertransport mit Vorfaltung, Abfüllteil, Rüttelung, Schliessorganen, Vakuum-Kammerrad und Paketauslauf,
• Fig. 36 eine partielle Ansicht der Verpackungsanlage mit Stapel für längsgesiegelte, flachgefaltete Packungs­zuschnitte, Schieber, Schere, Zuschnitt-Oeffner und -Zuführung auf Formrad, Formrad mit Beschickung der Kunststoffdeckel, Siegelstationen für Kunststoff­deckel und Transfer der Packungen auf Paketbecher­transport, Paketbechertransport mit Bodenschiene, Vorfaltung, Abfüllstelle und Rüttelung,
• Fig. 37 eine partielle Ansicht der Verpackungsanlage mit Paketbechertransport, Bodenschiene mit Verstellung, Abfüllstelle, Rüttelung, Füllstandtaster, Bodenfal­ter, Siegelstationen, Transferstationen auf und von Evakuierteil für Vakuum-Packungen, Schliessorgane und Packungsauslauf,
• Fig. 38 einen Grundriss der gesamten Verpackungsanlage mit horizontalem Stapel für längsgesiegelte, flachge­faltete Packungszuschnitte, Schere, Oeffner und Schieber für Zuführung der Packungszuschnitte auf den Formteil, Mitnehmerbänder für Zuführung der Kunststoffdeckel auf Formrad, Paketbecherkette mit Vorfalter, Abfüllteil, Faltorganen, Vorsiegelung, Ausstösser und Transferrädern für die Packungen auf und von Evakuierrad, mehrteiliges Vakuum-Kammerrad, Endschliessorgane und Packungsauslauf,
• Fig. 39 einen Schnitt durch die geschlossene Vakuum-Kammer mit einer Packung auf einer Bodenverstellplatte mit Paketklammern gehalten, mit offenen Pressern und Siegelorganen inkl. Antrieb für die Bodenfaltung,
• Fig. 40 einen Schnitt durch die geschlossene Vakuum-Kammer und die Packung, mit Bodenplatte für Pakethöhenver­stellung, Presser für konkave Packungsbodenformung in geschlossener Stellung und Siegelorgan kurz vor dem Schliessen,
• Fig. 41 eine Sequenz mit dem längsgesiegelten, flach gefal­teten Packungszuschnitt vor dem Oeffnen mit Führun­gen und Saugern,
• Fig. 42 eine Sequenz mit der geformten Packungshülse gehal­ten durch bewegliche Falter, fixe Rückwand und ein­geschwenkte, bewegliche Anschläge,
• Fig. 43 eine Sequenz mit der durch bewegliche Falter und Presser wieder flach gefalteten Packungshülse (Ueberknicken der Packungshülse),
• Fig. 44 eine Sequenz mit der wieder zurückgeformten Packungs­hülse vor dem Abschieben auf das Formrad,
• Fig. 45 einen aus einem Verbundpackstoff ab Rolle geformten, längsgesiegelten Packungsschlauch mit Abdeck-Schutz­streifen für Längsnaht,
• Fig. 46 eine überlappt gesiegelte Längsnaht mit Abdeck­Schutzstreifen über der innenliegenden Packstoff­schnittkante,
• Fig. 47 einen aus einem Verbundpackstoff ab Rolle geform­ten, längsgesiegelten Packstoffschlauch mit u-­förmigem Schutzstreifen für Längsnaht,
• Fig. 48 eine überlappt gesiegelte Längsnaht mit u-förmigem Schutzstreifen über der innenliegenden Packstoff-­Schnittkante,
• Fig. 49 einen Aufriss des Formteils der Verpackungsanlage mit Rollenentnahme für Packstoff über Splicer und Vorschubwalzen,
  Rollenentnahme und Vorrichtung zum Anbringen des Schutzstreifens,
  Vorschub und Einlauf des Packstoffs auf Faltkasten mit Schere und Vorschubrollen,
  mehrteiligem Formrad mit Falt- und Siegelorganen für Längsnaht,
  ferner Zuführung des Kunststoffdeckels und Siegel­organe für Kunststoffdeckel,
• Fig. 50 einen Grundriss des Formteils der Verpackungsanlage in der unter Fig. 45 beschriebenen Ausführung und mit Uebergang der Packungen vom Formteil auf den Paketbechertransport,
• Fig. 51 eine Sequenz des Packstoffeinlaufs auf Faltkasten unter Formrad mit abgeschnittenem Packstoffzu­schnitt in der Länge H + U unter Vorschubrollen und um den Faltdorn gefalteten Packungszuschnitt,
• Fig. 52 eine Sequenz des Packstoffeinlaufs auf Faltkasten unter Formrad mit Packstoffzuschnittende unter Vorschubrollen und vor Vorschubfingern und des Abschneidens der um die Länge ΔH vorgeschobenen Packstoffbahn bis zur Zentriermarke des nachfol­genden Packungszuschnittes,
• Fig. 53 eine Sequenz des Packstoffeinlaufs mit dem durch Finger auf den Faltkasten geschobenem Packungszu­schnitt vor dem Falten um den Faltdorn und dem Packstoffbahn-Vorschub vor der Schere um die Länge H + U.

The invention is explained in more detail below with reference to drawings. It shows:

• 1 is a vacuum pack for ground coffee with a plastic lid and tear tab,
• 2 such a pack when opening the pull tab,
• 3 such a pack during the partial removal of the ground coffee,
• 4 shows such a pack with a reclosed pull tab,
• 5 shows the structure of a composite packaging material,
• 6 shows the structure of a further composite packaging material variant,
• 7 a stack with flat folded, printed, pre-grooved and longitudinally sealed packaging material blanks,
• 8 shows an open, longitudinally sealed packaging blank (packing sleeve),
• 9 shows a longitudinal seam with an inner seam part peeled to half the packaging material, which is folded inside and sealed inside (finseal),
• 10 a stack with flat-folded, printed, pre-grooved and longitudinally sealed packaging material blanks in full length,
• 11 shows a flat folded, longitudinally sealed package cut shortened by the height ΔH and next to it an opened package sleeve,
• 12 is a packing sleeve with an inserted and sealed plastic cover with a tear tab,
• 13 is a pack with a plastic lid down,
• 14 is a pack with pre-folded bottom fold,
• 15 a pack filled to the hatched level with ground coffee,
• 16 is a shaken package with the fill level lowered to the hatched level,
• 17 a pack with folded and partially sealed bottom fold with opening for evacuating the air,
• 18 a pack with a concavely pressed-in bottom seal that is sealed after the air has been evacuated,
• 19 is a pack with folded and sealed folding tips,
• 20 shows a finished package with a plastic lid and tear-open tab upwards,
• 21 shows the floor plan of a plastic cover with a pull tab,
• 22 shows a longitudinal section through the plastic cover and the tear-open tab,
• 23 shows a longitudinal section through the plastic cover,
• 24 shows a cross section through the plastic cover and the tear-open tab,
• 25 shows a cross section through the plastic cover,
• 26 is an enlarged detail of the plastic cover with heating of the end edge of the mandrel,
• 27 is an enlarged detail of the plastic cover with the tear tab,
• 28 shows the floor plan of a plastic slip lid with a pull tab,
• 29 shows a longitudinal section through the plastic slip lid and the tear-open tab,
• 30 shows a longitudinal section through the plastic slip lid,
• 31 shows a cross section through the plastic slip lid with pull tab,
• 32 shows a cross section through the plastic slip lid,
• 33 is an enlarged detail of the plastic slip lid,
• 34 is an enlarged detail of the plastic slip lid with pull tab,
• 35 is a view of the entire packaging system for the production of the vacuum packs from the longitudinally sealed, flat-folded pack blank with stack of blanks, feed of the pack blanks, molded part, plastic lid feed, parcel cup transport with pre-folding, filling part, vibrating, closing elements, vacuum chamber wheel and parcel outlet,
• Fig. 36 is a partial view of the packaging system with stack for longitudinally sealed, flat-folded package blanks, slider, scissors, cut opener and feeder on the form wheel, form wheel with loading of the plastic cover, sealing stations for plastic cover and transfer of the packs to package cup transport, package cup transport with bottom rail, pre-folding , Filling point and shaking,
• 37 is a partial view of the packaging system with package cup transport, bottom rail with adjustment, filling point, shaking, level sensor, bottom folder, sealing stations, transfer stations on and from the evacuation part for vacuum packs, closing elements and pack outlet,
• 38 shows a floor plan of the entire packaging system with a horizontal stack for longitudinally sealed, flat-folded package blanks, scissors, openers and sliders for feeding the package blanks onto the molded part, carrier belts for feeding the plastic cover onto the molded wheel, package cup chain with pre-folder, filling part, folding elements, pre-sealing, ejector and Transfer wheels for the packs on and from the evacuation wheel, multi-part vacuum chamber wheel, end closing elements and pack outlet,
• 39 shows a section through the closed vacuum chamber with a package held on a floor adjustment plate with package clips, with open pressers and sealing elements including a drive for the bottom folding,
• 40 shows a section through the closed vacuum chamber and the packing, with base plate for package height adjustment, presser for concave packing base molding in the closed position and sealing element shortly before closing,
• 41 shows a sequence with the longitudinally sealed, flat-folded package blank before opening with guides and suction cups,
• 42 shows a sequence with the shaped packing sleeve held by movable folders, fixed rear wall and pivoted-in, movable stops,
• 43 shows a sequence with the packing sleeve folded flat again by means of movable folders and pressers (bending of the packing sleeve),
• 44 shows a sequence with the packaging sleeve which has been reshaped again before being pushed onto the molding wheel,
• 45 shows a longitudinally sealed packing tube formed from a composite packaging material from a roll, with protective protective strips for the longitudinal seam,
• 46 shows an overlapped sealed longitudinal seam with protective protective strips over the inner packaging material cut edge,
• 47 shows a longitudinally sealed packaging tube formed from a composite packaging material from a roll with a U-shaped protective strip for the longitudinal seam,
• 48 shows an overlapped sealed longitudinal seam with a U-shaped protective strip over the inner packaging material cutting edge,
• 49 shows an elevation of the molded part of the packaging system with roll removal for packaging material via splicer and feed rollers,
  Roll removal and device for attaching the protective strip,
  Feed and infeed of the packaging material on folding box with scissors and feed rollers,
  multi-part form wheel with folding and sealing elements for longitudinal seam,
  also feeding the plastic lid and sealing elements for plastic lids,
• Fig. 50 is a plan view of the molded part of the packaging system in the embodiment described under Fig. 45 and with the transition of the packs from the molded part to the package cup transport,
• 51 shows a sequence of the packaging material infeed on the folding box under the forming wheel with the packaging material cut off in the length H + U under feed rollers and the packaging blank folded around the folding mandrel,
• 52 shows a sequence of the packaging material infeed on the folding box under the molding wheel with the packaging material cut end under feed rollers and in front of feed fingers and the cutting of the packaging material web advanced by the length ΔH up to the centering mark of the subsequent package cut,
• 53 shows a sequence of the packaging material infeed with the packaging blank pushed onto the folding box by fingers before folding around the folding mandrel and the packaging material feed in front of the scissors by the length H + U.

In the above explanation of the figures and in the description of the method below, the following length designations are used for the packaging material:
H max = max. Package height,
U = length of the excess packaging material for the bottom folding,
H = variable fill level of the product after filling and shaking,
= variable pack height during production,
ΔH = H max - H = difference between max. Package height and variable production package height by which the package cut or packaging material must be shortened before the package is formed,
H max + U = max. Length of the longitudinally sealed package blank or centering mark spacing for the printed packaging material when the package is manufactured from a roll.

• 1 = Packstoff
• 2 = Trägermaterial aus Cellulose-Karton mit Holzschliff­anteil, einseitig gestrichen für das Bedrucken, von 210 - 260 g/m², das auf der Innenseite durch ein
• 3 = Niederdruck-Polyäthylen von 15 - 20 g/m² mit einer
• 4 = Aluminiumfolie von 8 - 12 µ laminiert wird. Diese Alu­miniumfolie erhält innen eine Beschichtung mit einem
• 5 = Niederdruck-Polyäthylen von 65 - 85 g/m², und ab­schliessend wird das Trägermaterial aussen mit einem
• 6 = Niederdruck-Polyäthylen von 25 - 30 g/m² beschichtet.

In the method described below, a stiff but still flexible composite packaging material 1 according to FIG. 5 is used for the single-layer vacuum pack. 5, for example, it can consist of the following positions:

• 1 = packaging material
• 2 = Backing material made of cellulose cardboard with groundwood, coated on one side for printing, from 210 - 260 g / m², which is covered on the inside by a
• 3 = low pressure polyethylene of 15 - 20 g / m² with one
• 4 = 8 - 12 µ aluminum foil is laminated. This aluminum foil gets a coating on the inside
• 5 = low-pressure polyethylene of 65 - 85 g / m², and finally the backing material is covered with a
• 6 = low pressure polyethylene coated from 25 - 30 g / m².

• 8 = Kaschiermittel verbundene
• 9 = Polypropylen- oder Nylon-Folie ersetzt werden.

In the case of the composite packaging material variant 7 according to FIG. 6, the low-pressure polyethylene coating 6 on the outside of the carrier material 2 can, for example, be covered with a

• 8 = laminate connected
• 9 = polypropylene or nylon film to be replaced.

Other insert / packaging material combinations are also conceivable which are suitable with regard to O₂ permeability, sealability, machinability, costs etc. The longitudinally sealed and flat-folded package blanks or sleeves 10 shown in FIG. 7 can be produced and stacked from this rigid, but still flexible, printed and pre-grooved composite packaging material 1 and 7. The longitudinal seam according to FIG. 9 is produced by peeling the inner seam section to half the packaging material thickness, folding over and sealing against the inside of the outer seam section. This creates a finseal with a seam sealed on the inside against the inside.

The design of the composite packaging material 1 and the package blank 10 sealed with the longitudinal seam according to FIG. 9 are known and are used today in aseptic liquid packaging. The production of the cubic vacuum pack from the longitudinally sealed, flat-folded pack blanks 10 with the shaping, prefolding, filling, shaking, closing, evacuating, sealing and finishing folding is shown in FIGS. 10 to 20. FIGS. 21 to 27 show the possible design of a plastic lid 11 with a tear-open tab. The embodiment variant of a plastic slip lid 12 with a tear-open tab is shown in FIGS. 28 to 34. This lid design has the advantages of stacking for loading and sealing onto the packing tube without counter with a mandrel. A disadvantage for this plastic slip lid is the somewhat higher manufacturing costs.

The method can be carried out on a packaging system shown in FIGS. 35 to 38. It should be noted for packs with ground coffee that the packs for evacuating the air must be fully filled and shaken so that the external overpressure does not unsightly deform the packs after the vacuum chamber has been evacuated and vented. Since the filling volume of the ground coffee varies despite regular grinding and thorough mixing during packaging production, the variable package height H record this volume change. It is therefore necessary to adjust the length H max + U of the longitudinally sealed, flat-folded pack blanks 10 to the pack height H during production, ie to shorten the length Δ H = H max - H and to cut off the hatched section 10 '.

In the method described below, this can be achieved (Fig. 36) by pushing the pack blanks 10 from the stack of blanks 13 at position A to position B with a slide 14 and shortening the flat-folded blanks 10 at position B on the pre-grooved side Bottom opposite side by the length ΔH of the hatched blank 10 '. The maximum package height H max with ΔH = o is achieved with the maximum stroke of the slide 14 and the minimum package height with ΔH max with the minimum stroke of the slide 14. The stroke of slide 14 can be adjusted with the servomotor 17 mounted on the drive lever 16. This changes the stroke of the drive lever 20 for the slide 14 via an adjusting link 18 and a pull rod 19. The actuation of the servomotor 17 can be carried out in the closing part of the packaging system together with the adjustment of the bottom rails 34 and 53 of the package cup transport 33, trend-controlled by the fill level button 48 . The suction line 21 takes care of the removal of the cut package cut pieces 10 '.

After shortening the pack blanks 10 at item B, they can be pushed with the slide 22 to position C, where the flat-folded pack blanks 10 are opened with the suction cups 23 (see also FIGS. 41-44). The opened packing sleeve 10 can be pushed onto a multi-part, form-shifting mold wheel 24 at position D, which can also be carried out with the slide 22 provided with two drivers. This pushing of the packing sleeve 10 onto a molded part, for example a molded wheel 24 at item D, can be facilitated by moving the two-part mandrels of the molded wheel 24. At item E of the molded wheel 24, the plastic covers with pull tabs 11 and 12 can be clocked and synchronized with driving belts 25 and 26 are fed to the packaging system and pushed onto the forming wheel 24 with a slide 27. The plastic lid with tear tab 11 and 12 can be inserted and fixed in the packing sleeve 10 with a press 28 at position E of the molding wheel. The insertion of the plastic cover 11 and 12 into the packing sleeve 10 is facilitated by a conical design of the cover shaft. A negative circumferential tolerance of the packing sleeve 10 (too narrow) in the practical area can be compensated for by tensioning it with the two-part mandrels of the molding wheel 24. In the following item F of the molding wheel 24, the repeated fixing of the plastic cover 11 and 12 with a press 29 and the sealing in the packing sleeve 10 on the broad sides with heat presses or sealing members 30. Resealing the broad sides can be carried out at item G of the molding wheel 24 with further heating presses 30 and at the following stations item J and K of the molding wheel 24 the plastic covers 11 and 12 can be sealed on the narrow sides of the package 10 with the heating presses 31 . The sealing of the plastic cover 11 can expediently, as shown in Fig. 26, with a built in the edges of the end faces of the two-part mandrel 24 heating 24 'supported. In the described embodiment, all heaters 30, 31 and 24 'are temperature controlled. The transfer of the packs 10 with the sealed-in plastic cover with the tear-open tab 11 and 12 from the forming wheel 24 at the station Pos. L into the circuit cup transport 33, which operates in a switching manner, is provided by continuously operating side chains 32 with stripping fingers. In the package cup transport 33, the packs 10 with the sealed-in plastic lid with tear-open tabs 11 and 12 slide downward on a height-adjustable bottom rail 34. Before filling, the pre-grooved, later bottom fold of the pack 10 is folded with a folding counter-holder 35 and the two outer broadside presses 36 pre-folded. Subsequently, a conical mandrel 37 entering the pack 10 reopens the pre-folded bottom fold. The ground coffee is filled into the vacuum packs 10 (FIGS. 36 to 38) in the package cup transport 33 with filling scales 38 via concurrent filling funnels 39. Instead of filling with filling scales 38, the ground coffee can also be filled into the vacuum packs 10 with screw doses. The compacting or lowering of the ground coffee in the vacuum packs 10 can be carried out with a vibrating device 40 during the filling process and via several cup transport stations connected to it. In this vibrating device 40, the filled vacuum packs 10 slide on a vibrating rail 41, which are driven up and down by a motor 42 via tie rods 43 and angle levers 44. This vibrating device 40 can be adjusted with vertical adjusting spindles 45 and chain drives 46 by a servomotor 47 in the level of the respective package height H. The actuation of this servomotor 47, like that of the servomotor 17 mentioned above on the molded part 24, can also be carried out with the fill level sensor 48 installed after intensive vibration 40 using the trend control 49. With the servomotor 47, adjusting nut 50, angle lever 44, 51 and tie rods 52, the already mentioned bottom rail 34 before filling and shaking, as well as the bottom rail 53 after shaking and evacuating can be adjusted automatically according to the package height. The number of measured values for a control step and the size of the control steps of the tendency control 49 are to be determined in such a way that the pack 10 absorbs the volume changes resulting from the Approx. 20 machine cycles of inputting the measured values of the fill level sensor 48 and the corrections thus determined via the tendency control 49 for the blank length of the pack 10 mentioned can occur. After the fill level button 48, the vacuum packs 10 are closed with folders 54 and partially sealed with sealing elements or heating presses 55. This is followed by the transfer of the vacuum packs 10 from the package cup transport 33 with an ejector 56 via a multi-part, continuously rotating packing clamp wheel 57 to the multi-part, continuously rotating vacuum chamber wheel 58. In the vacuum chambers 59, which are lifted off during the pack transfer, the vacuum packs 10 can, as shown in FIG. 39 shows, with packing clips 60 held on a base plate 61, the height can be adjusted so that the level of the bottom fold at the top remains constant with a varying packing height H. The adjustment of the base plate 61 can be carried out synchronously with the base rail 34 or 53. The air can be evacuated from the packs 10 or from the chambers 59 via the pipe 62 with the press members 63 and 64 open and the seal member 65 open. 40 shows how the bottom fold and the coffee level in the packs 10 can be formed concave with the presses 63 and 64 after the air has been evacuated, before the middle part of the spread fold is finished with the temperature-controlled sealing member 65. The press drive 63 and 64 and the sealing member 65 can be carried out via the drive members 66. With the concave shaping of the bottom fold, it is important that this can be done before the final sealing and venting of the chambers 59, because the overpressure acting on the packs 10 (the vacuum packs 10 are hard after venting) makes a later change in the shape of the bottom fold impossible. It is also conceivable to achieve a concave shape of the package base by keeping the level of the product in the packages 10 by an amount of, for example, 3 to 5 mm below the horizontal base groove, as a result of which the base fold is concave after the evacuation due to the external overpressure is pressed on the product. A concavely shaped base fold is required so that the package 10 stands stable on the outer edge of the package bottom. A reliable solution to this is provided by the embodiment shown in FIGS. 39 and 40 and described above. The chambers can also be ventilated after the finished sealing and opening of the chambers via the pipe 62. After the evacuation, the packages 10 were conveyed back into the package cup transport 33 via the multi-part, continuously rotating package clamp wheel 67 and the pushers 68 with the chambers 59 open. In the package cup transport 33, the bottom fold can be closed with the folding folder 69 and in the following station with the closing folder 70 for folding in the folding tabs. Sealing the folding tips at Final folder 70 can be done with hot air, which is guided with blower 72, air heater 73 and nozzles 71 onto the bottom folding tab. After an additional folding press 74, the finished packs 10 can leave the system via the ejector 75 and the belt outlet 76.

A nicer shape of the pack 10 with cleanly executed longitudinal edges can be achieved by bending the packing sleeve 10 after opening according to FIGS. 41 to 45. These show in FIG. 41 the opening of the longitudinally sealed and flat-folded pack blanks 10 with the lower guide 77 and the upper guide 78 through the suction cups 23. As shown in FIG. 42, the opened pack sleeve 10 is opened at the bottom by the movable folder plate 79, held at the top by the movable folder plate 80 and at the rear by the fixed rear wall 81. The pivoted, movable stops 82 and 83 prevent lateral evasion. The packing sleeve 10 is then, as shown in FIG. 43, folded so flat by the movable folding plates 79 and 80 and the pressers 84 that the two longitudinal grooves, which in the case of the flat-folded blank 10 in the magazine have a short opening angle of 180 ° before opening have one of 0 °. This reduces the restoring force of the packaging material in the aforementioned longitudinal grooves. This gives the packing sleeve 10 a nicer rectangular shape. After this buckling, the packing sleeve 10, as shown in Fig. 44, guided by the movable folding plates 79 and 80, the fixed rear wall 81 and the two pivoted, movable stops 82 and 83 with the slide 22 pushed onto the mandrels of the forming wheel 24 (Fig. 36).

As a variant, the process described below for the production of the vacuum packs from a roll can be considered , instead of from the printed, grooved, longitudinally sealed and flat-folded pack blank, as described above. In this variant, the packs can be produced from a printed, grooved, flexible composite packaging material 1 and 7 in FIGS. 5 and 6 with an overlapping sealed longitudinal seam in the manner known from the aseptic liquid packaging according to FIGS. 45-48. In the case of the packaging material web 85 (1 and 7), the inner cut edge is covered with a cover strip 86 according to FIGS. 45 and 46 or a U-shaped protective strip 87 according to FIGS. 47 and 48 for sealing the overlapped longitudinal seam. This cover strip 86 and protective strip 87 can consist of low-pressure polyethylene (NDPE) or a carrier material with double-sided coating with NDPE. Incidentally, the U-shaped protective strip 87 has the advantage that it additionally reinforces the seal coating.

In the aforementioned method variant, the printed, pre-grooved packaging material 85 provided with centering marks, as shown in FIGS. 49 and 50, can be fed from a stationary large roll 88 and a mobile large roll 89. The roll change can be done with an automatic splicer 90. The continuous removal of the packaging material 85 can be carried out with a continuous roller feed 91 driven by a control motor. This roller preference 91 is preferably regulated in order to deliver the correct amount of packaging material. The packaging material 85 therefore runs over a packaging material loop 92, each of which actuates a limit switch 94 and 95 via a roller carrier 93, which make the regulating motor of the preferred group 91 run faster or slower. The cover strip 86 and the protective strip 87 can be fed from rollers 96 and 96 'via an automatic splicer 97 and dancer rollers 98 to a device 99, 99' for attachment to the packaging material 85. This device 99, 99 'runs synchronously with the preference 100. After attaching the cover strip 86 or the protective strip 87, the packaging material 85 is conveyed further with a roller preference 100. This roller feed 100 is also preferably driven by a regulating motor in order to deliver the correct amount of packaging material. The packaging material 85 therefore runs with a packaging material loop 101 over a roller carrier 102, which in its end positions has a switch 103 and 104, the regulating motor of the roller preference 100 runs faster or slower. The machine-clocked conveyance of the packaging material 85 and the blanks 85 'is carried out by a roller feed 105 driven by a stepper motor via a punch 106, roller feed 107, feed finger 108 onto the folding box 109, which together with the longitudinal folders 110 and longitudinal presses 111, the packing sleeve 113 with the blank 85 'Forms on a multi-part, shift-wise moving mold wheel 112.

A possible way of working for the packaging material conveyance and the shortening of the packaging material blank 85 'to the correct length H + U before the packaging sleeve 113 is formed can be seen from the sequences shown in FIGS. 51 to 53. 51 shows the pack cut 85 ′ conveyed and separated by the punch 106 with the section length H + U measured from the packaging centering mark to the scissors 106. The length for the floor protrusion U remains constant, while H with the different coffee Volume and the corresponding package height changes. The value H is therefore also entered here (counted in) based on a level measurement after shaking in the closing part via a tendency control on the stepper motor of the roller feed 105. At the same time, Fig. 51 shows the packing sleeve 113 formed by the folding box 109, the longitudinal folders 110 and the longitudinal pressers 111 on the mandrel of the forming wheel 112 with the preceding packaging blank 85 '.

Fig. 52 shows the packaging material 85 advanced by ΔH and packaging material strips 85˝ cut off at the packaging material centering mark. Furthermore, FIG. 52 shows the pair of continuously conveying rollers 107 (lower rollers driven, upper shaft with rollers loosely placed rotating) in front of the two feed fingers 108 on the folding box 109. In the sequence shown in FIG the length ΔH transported away under the punch 106 after the package blank 85 'with the feed fingers 108 has been pushed onto the folding box 109. As shown in Fig. 49, 50 and 51, at the station Pos. M of the molding wheel 112 with this package blank 85 'through the folding box 109 and the longitudinal folder 110, the packing sleeve 113 is formed on the mandrel of the molding wheel 112 and held with moving longitudinal pressers 111 . The overlapped longitudinal seam of the packing sleeve 113 can then be sealed in the manner described earlier (FIGS. 45 to 48) with the temperature-controlled heating presses 114 on the two following molding wheel stations Pos. N and P of the molding wheel 112. At the station R of the molding wheel 112, the plastic cover with the tear-open tab 11 and 12 can be fed via a clocked conveyor belt 115 and pushed onto the packing sleeve 113 with the push-in element 116. After insertion into the packing sleeve 113, the plastic cover 11 and 12 is held between the stations Pos. R and S of the molding wheel 112 with a guide plate 117. Sealing the Plastic lid with tear tab 11 and 12 on the packing sleeve 113 can be carried out for the wide sides of the pack at the stations S and T of the molding wheel 112 with the heat pressers 118 and for the narrow pack sides at the stations V and W with the heat pressers 119. The sealing of the plastic cover 11 can be expedient, as shown in FIG. 26, with a heater 24 'installed in the front edges of the two-part mandrel mandrels 24'. In the mentioned method, all heaters (118, 119 and 24 ') are temperature controlled. The packing 113 with the sealed-in plastic cover with the tear-open tab 11 and 12 is removed from the forming wheel 112 at the station Pos. Z with the wipers 120. The transfer of the packing 113 to a package cup transport 33 which operates in a switching manner can be carried out with a package stand 121 and a sheet insert 122 . In this horizontal, clocked package cup transport, the pre-folding, filling, shaking, scanning, closing and evacuating the packs 113 can be carried out in the same way as in the previously described method with the procedure starting from the pre-sealed and flat-folded pack blank, shown in FIGS. 36 to 40.

When roasting coffee beans, CO₂ is produced, which is contained in the cells of the coffee beans with excess pressure. When grinding the bean coffee, the CO₂ can from the grinding open cells of the coffee grains escape. The CO₂ with excess pressure remains in the remaining closed cells. This CO₂ can slowly diffuse through the thin cell walls, causing the excess gas pressure in the cells to break down. The duration for the CO₂ to escape from the cells of the coffee grains depends on the degree of roasting, the degree of grinding, the origin and harvest of the coffee. In order to allow this CO₂ to escape from the ground coffee, it is temporarily stored under vacuum for a certain time before packaging. If the coffee is vacuum packed after grinding without intermediate storage, the CO₂ escaping with excess pressure can reduce the negative pressure in the vacuum packs and even cause the pack to expand. This inflation of the packs can, as shown in FIG. 1, be avoided by using a one-way pressure relief valve 124. Through this one-way pressure relief valve 124, CO₂ escapes to the outside at an overpressure in the package without air or oxygen (O₂) being able to enter the package.

In both of the described method variants, it is possible to equip the broad side of the packs 10 and 113 with a one-way pressure relief valve 124, as shown in FIG. 1. The disposable pressure relief valve 124 can be attached by sealing
- Pack 10 on the molding wheel 24 shown in Fig. 36 and at
Pack 113 take place on the molding wheel 112 shown in FIGS. 49 and 50.

Both of the above-described process variants can be carried out with packaging systems, the mode of operation of which can be seen from the described process steps and the execution and construction of which can be seen from the illustrations in FIGS. 35 to 50. Vacuum packaging systems of this type for the process variants mentioned can be designed for the operating data specified below:
Products: coarse to finely ground coffee beans (filling system for fine grinding, screw feeder), also free-flowing products that are packaged or evacuated and fumigated under vacuum, e.g. milk powder, Bircher muesli etc. Without an evacuation part, the packaging system can also be used for other free-flowing products that only need protection against moisture and loss of aroma.
Filling volume, shaken measured in 1 liter measuring glass 60 mm diameter approx. 450 - 1200 cm³.
Filling weights net, e.g. for ground coffee 250 - 500 g. Package information: e.g. for ground coffee
250 g: 78 x 42 x H = (140 - 165) mm
500 g: 95 x 63 x H = (150 - 180) mm
Pack cross section constant
H = area for automatic packing height adjustment.
Output of vacuum packaging system for the mentioned filling volume and packaging format range, e.g. approx. 4800 - 6000 packs / h.

Claims (10)

1. A process for producing a vacuum pack for free-flowing products, in particular ground coffee, in insert packs (10, 113), characterized in that printed from rigid, but relatively flexible composite packaging materials (1,7), on the longitudinal edges and at the bottom fold pre-grooved and overlapped longitudinally sealed, flat-folded pack blanks (10) are produced which, before opening the pack sleeve (10) in accordance with a statistically controlled tendency control (49) with a punch (15) around a pack section (10 ') on one corrected length of the package blank (10) can be shortened, the tendency control (49) being regulated by the measured values of the level heights which result after the product has been filled and compacted in the packages (10). 2. The method according to claim 1, characterized in that the package blank (10) is first opened and then provided on a mandrel molding wheel (24) with a plastic cover with a tear-open tab (11, 12), the plastic cover (11, 12) is sealed into the packing sleeve (10) by means of temperature-controlled sealing members (30, 31) and the subsequent packaging is subsequently carried out in a package cup transport (33). 3. The method according to claim 1 or 2, characterized in that the composite packaging material (1, 7 and 85) with a preferred group (91) of rollers (88, 89) regulated by buffering (92 to 95) is removed, followed by a cover strip (86) or a protective strip (87) of further rolls (96, 96 ') is sealed onto the packaging material web (85) in such a way that the packaging material cutting edge on the inside of the packaging (113) is covered when the overlapped longitudinal seam is sealed , and that the packaging material web (85) is subsequently fed with a preferred group (100) regulated by the buffering (101-104) to a roller feed (105) which is controlled by pressure centering marks and by the tendency control (49) which with the punch (106), cuts the packaging material blanks (85 ′) to the corrected blank length and then conveys them with a roller feed (107) and feed fingers (108) onto the folding box (109), with which, supported by longitudinal folders (110) and Longitudinal press (111), the packing sleeve (113) is formed on the mandrel molding wheel (112), the overlapping longitudinal seam being sealed with the temperature-controlled sealing members (114) on the following molding wheel stations before a next station of the molding wheel (112 ) the plastic lid with the tear-open tab (11, 12) is fed into and inserted into the packing sleeve (113), the plastic lid (11, 12) being sealed into the packing sleeve (113) with further temperature-controlled sealing members (118, 119) on the following forming wheel stations and, subsequently, pushing (120) and transferring the packs (113) into a package cup transport (33) takes place. 4. The method according to claim 1, 2 or 3, characterized in that the packs (10, 113) with the plastic cover (11, 12) are moved down in the packet cup transport (33) in a switching manner, with the empty packs (10, 113) for the time being The pre-grooved bottom fold above is folded with folding elements (35, 36) and the bottom fold is reopened with a folding mandrel (37), and then the packs (10, 113) are filled with filling scales (38) or screw feeders and vibrated intensively during and after filling, before the level of the product in the packs (10, 113) is measured by a button (48), with the help of the values determined by the statistically controlled tendency Control (49) the package blank (10) or the packaging blank (85 ′) is shortened to the corrected length by additionally the bottom rails (34, 41, 53) over the entire package cup transport (33) according to the variable height of the package (10, 113) can be raised or lowered in such a way that the folding and closing of the bottom fold of the pack (10, 113) takes place at a constant level, whereby, in addition to the aforementioned pre-folding, further process steps are also affected in the packs (10, 113). 5. The method according to claim 4, characterized in that these further process steps, an expansion fold with folding members (54), a partial sealing with further sealing members (55) and after evacuation in a separate vacuum chamber wheel (58) folding the finished sealed floor -spread folding of the packs (10, 113) with a further folder (69), as well as folding and sealing the bottom folding tabs with an additional folder (70), hot air nozzles (71) and a press (74). 6. The method according to claim 4 or 5, characterized in that the packs (10, 113) with the spreading fold partially sealed in the package cup transport (33) are transferred into a separate, multi-part, continuously rotating vacuum chamber wheel (58), where they are transferred into vacuum chambers (59) held with movable packing clips (60) Base plates (61), which are automatically adjusted to the variable pack heights using the tendency control (49), that after the evacuation process, with the help of two presses (63, 64), the pack bottom is formed into a concave shape, and that the vacuum Packs (10,113) then after sealing the base spread with another temperature-controlled sealing element (65) and after ventilating and opening the vacuum chambers (59) back into the package cup transport (33) for the final folding of the vacuum packs (10,113) be promoted, or alternatively the concave shape of the bottom of the vacuum packs (10, 113) is achieved by keeping the shaken fill level of the product by an amount below the bottom grooves, as a result of which the folded and sealed in the vacuum chamber (59) Bottom folding due to the external overpressure after the vacuum chambers have been vented to the product Ni, which is deeper than the bottom grooving veau is pressed. 7. The method according to any one of claims 1 to 6, characterized in that the packing sleeve (10) with suction cups (23) opened and then with the help of folding plates (79, 80), counterholders (82, 83) and presser (84) folded over in such a manner and then it is pressed that the two longitudinal grooves of the packaging material, which in the case of the flat-folded packing sleeve (10) in the stack (13) have an opening angle of Hold 180 °, briefly obtain one of 0 ° and then bring it back to an opening angle of 90 ° before the packing sleeve (10) is pushed onto the molding wheel (24). 8. The method according to any one of claims 1, 4, 5, 6 or 7, characterized in that the package blanks (10) with corrected length after opening without a mandrel form wheel (24, 112) are pushed directly into a package cup transport (33) which is moved in a switching manner that a clocked plastic slip lid with tear-open tab (12) is inserted and pressed into the packing sleeve (10) standing in the packet cup chain (33) from below, that the edge of the slip lid is repeatedly sealed onto the packing sleeve (10) with temperature-controlled heating tongs , and that the vacuum packs (10) are then filled, shaken, evacuated and sealed. 9. The method according to any one of claims 1 to 7, characterized in that the vacuum packs (10,113) are equipped with a one-way pressure relief valve (124) to cause the filled, evacuated and fully sealed packs (10,113 ) CO₂ can escape without air entering it from the outside, the one-way pressure relief valve (124) being ordered and clocked in each case on the switch-shaped mandrel mold wheel (24, 112) and sealed onto the package (10, 113). 10. Packaging system for performing the method according to one of claims 1 to 9, characterized in that the different assemblies form an integrated unit.

Images