FIELD OF THE INVENTION

[ 01 ] The invention relates to a packing case packing method, and corresponding apparatus, for packing a content, such as a loose product, perforated bags containing a loose product, articles like bags or cases containing a product, and the like, into a packing case, wherein the packing case has a packing case height as measured between opposing first and second sides of the packing case. The invention further relates to an associated packing case erecting method, and corresponding apparatus, for erecting a packing case.

BACKGROUND OF THE INVENTION

[ 02 ] Packing case packing methods and corresponding apparatus are widely employed for packing a content of products into packing cases, which are generally card board boxes, for shipment. The size of the packing cases is generally chosen specifically for the content to be packed. However, it may occur that the size of a packing case does not fit the content. In some applications a varying content is packed in a packing case of a fixed size, while any space not filled by the content may be left open or is filled with a dedicated open space filler like one or more air cushions. Effectively, a lot of air is transported in such instances.

[ 03 ] In another application, a content of which the volume may change over time is packed into packing cases. This may, for instance, apply to perforated bags of frozen and yet unfried French fries. When filling the bags with the French fries, quite some air is filled into the bags as well and the French fries are not closely packed in the bags. Subsequently, the bags are packed in packing cases. The size of the packing cases can be chosen to fit a content of a number of such bags with French fries, but during shipping the French fries will become more closely packed and air will escape. This will leave an empty headspace above the content. Generally, a number of packing cases with content are stacked and shipped together, and the content inside the packing cases contributes to the structural strength of the packing case and the stack of packing cases. Having an empty headspace above the content, will severely reduce the structural strength. The content can be compacted so that no empty headspace remains. However, with some products, like French fries, the volume of the content may vary with time. The water content of potatoes, and thus of the French fries, will change with the season, which causes the volume to change for a given weight of the content. The size of packing cases, especially the height, should therefore preferably change over time to fit the content. Practically, the packing cases are limited to a number of sizes having a selected packing case height. Unfortunately, this may still cause an underfill and thus an empty headspace or an overfill of packing cases. Both are undesired.

[ 04 ] Methods and apparatuses are known to adapt the height of a packing case while the content is present inside the packing case. The height of the packing case is adapted based on the content of the packing case at that moment by providing some machine parts into the packing case to adapt its height. This may damage the content, especially when bags such as the perforated bags with French fries are involved, but will generally also cause a slow-down of the packing case packing process. Both are quite undesired as well.

SUMMARY OF THE INVENTION

[ 05 ] It is an objective of the invention to provide a packing case method and apparatus that are very flexible in adapting a packing case height of packing cases.

[ 06 ] It is another or alternative objective of the invention to provide a packing case method and apparatus that incorporate to adapt a packing case height in available packing case methods and apparatuses.

[ 07 ] It is yet another or alternative objective of the invention to provide a packing case method and apparatus that do not risk damaging the contents of a packing case.

[ 08 ] It is yet another or alternative objective of the invention to provide a packing case method and apparatus that allow for a feedback of a required packing case height.

[ 09 ] It is yet another or alternative objective of the invention to provide a packing case method and apparatus that allow for the regulation of the case height for consecutive cases with the same content.

[ 10 ] It is yet another or alternative objective of the invention to provide a packing case method and apparatus that allow for regulation to provide packing cases with an optimal height for the content.

[ 11 ] In an aspect the invention provides for a packing case packing method for packing a content, such as a loose product, perforated bags containing a loose product, articles like bags or boxes containing a product, and the like, into a packing case, wherein the packing case has a packing case height as measured between opposing first and second sides of the packing case, and wherein the method comprises

- a content height determining step of determining a height of the content when packed in the packing case on the first side of the packing case;

- a case height setting step of setting a predetermined packing case height based on the height of the content when packed in the packing case as determined in the content height determining step;

- a case erecting step of erecting the packing case from a preform with the second side of the packing case open, which comprises providing the preform for forming the packing case, wherein the preform allows for adjusting the packing case height to the predetermined packing case height, and adjusting the preform to the predetermined packing case height;

- a case filling step of filling the packing case with the content onto the first side of the packing case through the open second side of the packing case; and

- a case closing step of closing the second side of the packing case, wherein the case height setting step is subsequently followed by one or more successive cycles of subsequent case erecting, case filling and case closing steps.

[ 12 ] In another aspect the invention provides for a packing case packing apparatus for packing a content, such as a loose product, perforated bags containing a loose product, articles like bags or boxes containing a product, and the like, into a packing case (20), wherein the packing case has a packing case height as measured between opposing first and second sides of the packing case, and wherein the apparatus comprises

- a content height determining arrangement for a content height determining step of determining a height of the content when packed in the packing case on the first side of the packing case;

- a case height setting arrangement for a subsequent case height setting step of setting a predetermined packing case height based on the height of the content when packed in the packing case as determined in the content height determining step by the content height determining arrangement;

- a case erecting arrangement for a case erecting step of erecting the packing case from a preform with the second side of the packing case open, which comprises providing the preform for forming the packing case, wherein the preform allows for adjusting the packing case height to the predetermined packing case height, and adjusting the preform to the predetermined packing case height;

- a case filling arrangement for a case filling step of filling the packing case with the content onto the first side of the packing case through the open second side of the packing case; and

- a case closing arrangement for a case closing step of closing the second side of the packing case, wherein the apparatus is configured so that the case height setting step is subsequently followed by one or more successive cycles of subsequent case erecting, case filling and case closing steps.

[ 13 ] In an embodiment, the content height determining step is executed during or directly after the case filling step of at least one of the one or more successive cycles of subsequent case erecting, case filling and case closing steps.

[ 14 ] In an embodiment, the content height determining step is executed during or directly after the case filling step of every one or of a last one or of every n ^th one, n being an integer number, of the one or more successive cycles of subsequent case erecting, case filling and case closing steps.

[ 15 ] In an embodiment, the content height determining step is executed during one or more separate steps of filling a packing case, or a partially erected preform corresponding to the packing case with an open second side, with the content.

[ 16 ] In an embodiment, the case height setting step is repeatedly executed and is each time subsequently followed by one or more successive cycles of subsequent case erecting, case filling and case closing steps.

[ 17 ] In an embodiment, the case height setting step is executed before packing a batch of packing cases.

[ 18 ] In an embodiment, the case height setting step is executed when a height of the content as determined in the content height determining step has changed more than a predetermined amount as compared to a height of the content as determined for executing a last case height setting step.

[ 19 ] In an embodiment, wherein the packing case has interconnected side walls defining a circumference of the packing case and has first and second flaps attached to opposing first and second ends, respectively, of the side walls, which first and second ends of the side walls correspond to the first and second sides, respectively, of the packing case for closing the first and second sides of the packing case, wherein the preform has interconnected panels associated with the interconnected side walls of the packing case and first flaps attached to corresponding first ends of the panels, the first ends of the panels and the first flaps of the preform correspond to the first ends of the side walls and the first flaps of the packing case, respectively, and the panels have second ends opposing the respective first ends of the panels, wherein the case erecting step comprises

- providing an erected preform by arranging the panels of the preform to have mutual positions corresponding to mutual positions of the side walls of the packing case with respect to one another, and closing the first flaps to provide the erected preform having a closed first side corresponding to the first side of the packing case and the erected preform having an open second side opposing the closed first side of the erected preform;

- providing the side walls and the second flaps of the packing case from the panels of the erected preform, which comprises providing a score line in the panels to define the side walls and the second end of the side walls of the packing case, wherein the score lines are provided at a distance from the first side of the erected preform which corresponds to the predetermined packing case height, to provide the packing case with an open second end, and wherein the case closing step comprises closing the second flaps.

[ 20 ] In another aspect the invention provide for a packing case erecting method for erecting a packing case from a preform, wherein the packing case has a packing case height as measured between opposing first and second sides of the packing case, wherein the packing case has interconnected side walls defining a circumference of the packing case and has first and second flaps attached to opposing first and second ends, respectively, of the side walls, which first and second ends of the side walls correspond to the first and second sides, respectively, of the packing case for closing the first and second sides of the packing case, wherein the preform has interconnected panels associated with the interconnected side walls of the packing case and first flaps attached to corresponding first ends of the panels, the first ends of the panels and the first flaps of the preform correspond to the first ends of the side walls and the first flaps of the packing case, respectively, and the panels have second ends opposing the respective first ends of the panels, and wherein the method comprises

- a preform providing step of providing a preform for forming the packing case, wherein the preform allows for adjusting the packing case height to a predetermined packing case height;

- a case height setting step of setting the predetermined packing case height;

- a preform erection step of providing an erected preform by arranging the panels of the preform to have mutual positions corresponding to mutual positions of the side walls of the packing case with respect to one another, and closing the first flaps to provide the erected preform having a closed first side corresponding to the first side of the packing case and the erected preform having an open second side opposing the closed first side of the erected preform;

- a case definition step of providing the side walls and optionally the second flaps of the packing case from the panels of the erected preform, which comprises providing a score line in the panels to define the side walls and the second end of the side walls of the packing case, wherein the score lines are provided at a distance from the first side of the erected preform which corresponds to the predetermined packing case height, to provide the packing case with an open second end.

[ 21 ] In another aspect the invention provides for a packing case erecting apparatus for erecting a packing case from a preform, wherein the packing case has a packing case height as measured between opposing first and second sides of the packing case, wherein the packing case has interconnected side walls defining a circumference of the packing case and has first and second flaps attached to opposing first and second ends, respectively, of the side walls, which first and second ends of the side walls correspond to the first and second sides, respectively, of the packing case for closing the first and second sides of the packing case, wherein the preform has interconnected panels associated with the interconnected side walls of the packing case and first flaps attached to corresponding first ends of the panels, the first ends of the panels and the first flaps of the preform correspond to the first ends of the side walls and the first flaps of the packing case, respectively, and the panels have second ends opposing the respective first ends of the panels, and wherein the apparatus comprises

- a preform providing arrangement for a preform providing step of providing a preform for forming the packing case, wherein the preform allows for adjusting the packing case height to a predetermined packing case height;

- a case height setting arrangement for a case height setting step of setting the predetermined packing case height; - a preform erection arrangement for a preform erection step of providing an erected preform by arranging the panels of the preform to have mutual positions corresponding to mutual positions of the side walls of the packing case with respect to one another, and closing the first flaps to provide the erected preform having a closed first side corresponding to the first side of the packing case and the erected preform having an open second side opposing the closed first side of the erected preform;

- a case definition arrangement for a case definition step of providing the side walls and optionally the second flaps of the packing case from the panels of the erected preform, which comprises providing a score line in the panels to define the side walls and the second end of the side walls of the packing case, wherein the score lines are provided at a distance from the first side of the erected preform which corresponds to the predetermined packing case height, to provide the packing case with an open second end.

[ 22 ] In an embodiment, the case definition step of providing the side walls and the second flaps of the packing case from the panels of the erected preform comprises cutting the preform at corners of the erected preform between adjacent connected panels from the second end of the panels opposing the first ends of the panels to the distance from the first side of the erected preform which corresponds to the predetermined packing case height.

[ 23 ] In an embodiment, the case definition step of providing the side walls and the second flaps of the packing case from the panels of the erected preform comprises holding the erected preform with the closed first side against a supporting surface.

[ 24 ] In an embodiment, the erected preform is held against the supporting surface by pressing from an inside of the erected preform onto the closed first side of the erected preform.

[ 25 ] In an embodiment, the case definition step of providing the side walls and optionally the second flaps of the packing case from the panels of the erected preform comprises providing an internal frame inside the erected preform through the open second side of the erected preform and an external frame around the erected preform along a direction from the second side toward the first side of the erected preform while having a gap between the internal and external frames for passing the panels, wherein one or both of the internal and external frames carry movable scoring blades for providing the score line in the panels in conjunction with an opposing scoring blade or a respective one of the internal and external frames, especially wherein the internal frame carries the movable scoring blades for providing the score line in the panels,

[ 26 ] In an embodiment, one or both of the internal and external frames have guide elements arranged on a side thereof, in operation, facing toward the first side of the erected preform for guiding the second ends of the panels into the gap between the internal and external frames. [ 27 ] In an embodiment, the scoring blades are arranged on a side of one or both of the internal and external frames, in operation, facing away from the first side of the erected preform.

[ 28 ] In an embodiment, the internal and external frames are mounted on a guide frame, and the guide frame is movable along the direction, in operation, from the second side toward the first side of the erected preform.

[ 29 ] In an embodiment, the step of providing the side walls and the second flaps of the packing case from the panels of the erected preform comprises pressing from the inside of the erected preform on the closed first side of the erected preform by a pressing member arranged on the guide frame.

[ 30 ] In an embodiment, the pressing member is movably arranged on the guide frame along the direction, in operation, from the second side toward the first side of the erected preform.

[ 31 ] In an embodiment, cutting blades are provided on one or both of the internal and external frames for cutting the preform at corners of the erected preform between adjacent connected panels from the second end of the panels opposing the first ends of the panels to the score line provided in the panels, especially wherein the cutting blades are provided on the internal frame.

BRIEF DESCRIPTION OF THE DRAWINGS

[ 32 ] Further features and advantages of the invention will become apparent from the description of the invention by way of non-limiting and non-exclusive embodiments. These embodiments are not to be construed as limiting the scope of protection. The person skilled in the art will realize that other alternatives and equivalent embodiments of the invention can be conceived and reduced to practice without departing from the scope of the present invention. Embodiments of the invention will be described with reference to the accompanying drawings, in which like or same reference symbols denote like, same or corresponding parts, and in which

Figure 1 shows a plan view of a blank for forming a preform for a packing case;

Figure 2 shows a side view of a preform taken from a pile of preforms;

Figure 3A shows a perspective view of the preform of figure 2 taken from the pile of preforms while still making contact with the pile of preforms;

Figure 3B shows the a perspective view of the preform of figure 3A above the pile of preforms and free from contact with the pile;

Figures 4A to 40 show perspective views of various stages of forming the packing case from an erected preform resulting from the preform in the stage of figure 3B;

Figure 5 shows another perspective view of the stage of figure 4A;

Figures 6A and 6B show a top view on the internal and external frames with the scoring blades in the retracted and extended positions, respectively, for making score lines in the erected preform; Figure 6C shows a bottom view on the external and internal frames with the scoring blades in the retracted position;

Figure 7 shows a detail of cutting the erected preform at the corners;

Figures 8A and 8B show perspective views of the packing case made from the preform of the previous figures on its second (top) and first (bottom) sides, respectively;

Figure 9 shows a packing case filling apparatus for providing bags with loose product into erected packing cases with an open second (top) side;

Figure 10A shows a compactor apparatus for compacting the bags with loose product provided in the erected packing cases with open second end;

Figure 10B shows a compactor roller bar of the apparatus of figure 10A;

Figures 11 A and 11 B schematically show compacting the bags with loose product in the erected packing cases with open second end; and

Figure 12 shows a graph of the height of content in a packing case as a function of time while compacting the content.

DETAILED DESCRIPTION OF EMBODIMENTS

[ 33 ] Figure 1 shows a blank 10B for finally making a packing case 20 through an intermediate (erected) preform 10 (10E). The blank 10B has four panels 13 and four first flaps 11 attached to first ends 13.1 of the panels. The panels 13 have second ends 13.2 opposing respective first ends 13.1 of the panels, and have side ends 13.3 connecting the first and second ends 13.1 , 13.2. A series of four panels 13 is connected to one another at their respective side ends 13.3. A first panel in the series has an unconnected side end 13.3, while a last panel in the series has a flap 14 connected to one side end 13.3. The flap 14 is for allowing a connection of the last panel in the series to the first panel in the series by, for instance, gluing the flap 14 to the unconnected side end 13.3 of the first side panel in the series to form a preform 10 as is shown in figures 2, 3A and 3B.

[ 34 ] The preform 10 has four interconnected panels 13, which means that all side ends 13.3 of the panels are connected to an adjacent panel. In a flat state of the preform 10, two adjacent panels of the preform are lying on top of two other panels of the preform, which allows to make a pile P of preforms 10, as is shown in figures 2, 3A and 3B. A preform on top of the pile P can be taken from the pile by employing, for instance, a movable arm with a suction holder 110 of a packing case erecting apparatus 101 for erecting packing cases 20 from preforms 10. Such packing case erecting apparatus can be part of a packing case packing apparatus for packing content into the erected packing cases 20.

[ 35 ] An erected packing case 20, as shown in a closed state in figures 8A and 8B, has opposing first and second sides 20.1 , 20.2, and interconnected side walls 23 defining a circumference of the packing case. First and second flaps 21 , 22 of the packing case are attached to opposing first and second ends 23.1 , 23.2, respectively, of the side walls. The first and second ends 23.1 , 23.2 of the side walls correspond to the first and second sides 20.1 , 20.2, respectively, of the packing case 20 for closing the first and second sides of the packing case. The interconnected side panels 13 of the preform 10 are associated with the interconnected side walls 23 of the packing case 20. The first ends 13.1 of the panels 13 and the first flaps 11 of the preform 10 correspond to the first ends 23.1 of the side walls 23 and the first flaps 21 of the packing case 20, respectively.

[ 36 ] Figures 2 and 3A show a preform 10 taken from the top of the pile P, while still making contact with the pile in a preform providing arrangement. This causes the preform to open so that the flat faces of the panels lying onto one another in the preform in the pile move out of contact. When the preform 10 taken by the suction holder 110 is raised at some distance from the pile, as shown in figure 3B, two beams 120 of a preform erection arrangement of the packing case erecting apparatus 101 come in and push from the sides against the preform so that adjacent panels make right angles with respect to one another. This corresponds to arranging the panels 13 of the preform 10 to have mutual positions corresponding to mutual positions of the side walls 23 of the packing case 20 with respect to one another. Subsequently, the first flaps 11 are closed to provide an erected preform having a closed first side 10.1 corresponding to the first side 20.1 of the packing case. The erected preform 10E has an open second side 10.2 opposing the closed first side 10.1 of the erected preform. Closure of the first flaps 11 is only schematically indicated by arrows in figure 3B, and is achieved by appropriate guiding elements of packing case erecting apparatus 101 , which are known as such. Figure 4A shows an erected preform 10E.

[ 37 ] Figures 4A to 4C show the side walls 23 and the second flaps 22 of the packing case 20 being formed from the panels 13 of the erected preform 10E in a case definition arrangement. A guide frame 190 with an internal frame 140 and an external frame 130 mounted thereon is moved with respect to the erected preform 10E in a direction from the second side 10.2 toward the first side 10.1 of the erected preform. The internal frame 140 is directly mounted on the guide frame 190, while the external frame 130 is mounted by guide frame brackets 195 on the internal frame 140. Figure 4A shows the state before movement of the external and internal frames toward the erected preform 10E. The internal frame 140 is, from the state as shown in figure 4A, provided into the erected preform, while the external frame 130 is provided around the erected preform, which is shown in figure 4B. A gap between the internal and external frames allows the panels 13 of the erected preform to pass there through while the internal and external frames move into and around the erected preform. Guide elements 135, 145 on the external and internal frames, respectively, guide the second ends 13.2 of the panels 13 into the gap between the internal and external frames. At the same time a pressing member 170 arranged on the guide frame 190 is extended with respect to the guide frame 190 for pressing against the inside of the first side 10.1 of the erected preform 10E to press the first side 10.1 against a supporting surface S, as is shown in figure 4B. This provides a well-defined position of the first side 10.1 for positioning the internal and external frames with respect to the first side 10.1 . Efficiently, this may be part of the process for erecting the preform to press the flaps 11 forming the first side 10.1 against each other, for instance, with a glue in between or a tape provided over opposite flap ends to join the flaps to close the first end 10.1.

[ 38 ] The external and internal frames 130, 140 are positioned at a distance from the first side 10.1 which corresponds to a predetermined packing case height to set the packing case height H20 of the packing case 20 to be formed from the erected preform 10E. Scoring blades 150 are arranged on a side of the internal frame 140 which faces away from the first side 10.1 of the erected preform 10E. Especially, the distance of the scoring blades 150 with respect to the first side 10.1 corresponds to the predetermined packing case height. Cutting blades 160 mounted at the corners of the internal frame 140 cut the preform at corners of the erected preform 10E between adjacent connected panels from the second side 10.2 of the preform to a position where the score line 25 is to be provided in the panels. Figure 7 shows the cutting in more detail.

[ 39 ] At the position of the predetermined packing case height H20, where the external and internal frames have reached their intended position with respect to the closed first side 10.1 of the erected preform 10E, the scoring blades 150 are moved outwards with respect to the internal frame 140, in the state as shown in figure 4B, to press the panels 13 of the erected preform 10E between the scoring blades 150 on one side of the panels and the external frame 130 on the other side of the panels, which provides a score line 25 in the panels 13 at a distance from the first side 10.1 which corresponds to the predetermined packing case height H20. Subsequently, the scoring blades 150 are retracted again and the guide frame 190 with external and internal frames 130, 140 and pressing member 170 are retracted from the packing case 20 with open second end 20.2, which has now been formed from the erected preform 10E, as is shown in figure 4C and figure 5. The score line 25 and the cutting of the corners of the preform have now formed the side walls 23 and flaps 22 at the second ends 23.2 of the side walls 23 at the second side 20.2 of the packing case 20. Figures 6A and 6B show top views on the external and internal frames 130, 140 with the scoring blades 150 in the retracted and extended positions, respectively. The scoring blades are moved through pressurized air cylinders 151. Figure 6C shows a bottom view on the external and internal frames with the scoring blades in the retracted position.

[ 40 ] Erected packing cases 20 with open second end 20.2 are provided by the packing case erector apparatus onto a packing case conveyor 400 of a packing case packing apparatus. Figure 9 shows a packing case filling apparatus 102 of the packing case packing apparatus. In the embodiment shown in figure 9, an article conveyor 210 and the packing case conveyor 400 are arranged alongside one another. Articles in the form of perforated bags A with frozen French fries are conveyed on the article conveyor 210 and picked from the article conveyor by pick-and-place delta robots 220 to be provided into the open packing cases 20 conveyed on the packing case conveyor 400. Figure 11A shows a number of perforated bags A with the frozen French fries stacked on top of one another in the open packing case 20 as the content C in the packing case 20. The content C of the stack of bags A projects from the open top end 20.2 of the packing case 20 due to an excess of air present in the bags and the French fries not being closely packed in the bags. Compacting of the content C is required to fit the content in the packing case.

[ 41 ] After filling of the content C of perforated bags A with frozen French fries in the packing cases on the packing case conveyor 400, the packing cases 20 are provided by the packing case conveyor 400 to a compactor apparatus 103 of the packing case packing apparatus for compacting of the content C in the packing cases. The compactor apparatus 103 is shown in figure 10A. The packing cases 20 with open second end 20.2 and with an uncompacted content C are provided by the packing case conveyor 400 to a supply end 103.1 of the compactor apparatus 103. After compacting, the packing cases 20 with open second end 20.2 and compacted content C are discharged at a discharge end 103.2 of the compactor apparatus 103. Figure 10A only shows a packing case 20 at the discharge end 103.2 of the compactor apparatus and a packing case further downstream on the packing case conveyor 400 for illustration purposes. Generally, in operation, a flow of packing cases with a content will pass over the packing case conveyor 400 with multiple packing cases on the packing case conveyer upstream of the supply end 103.1 , multiple packing cases on the stretch 400.3 of the packing case conveyor in the compactor apparatus 103 and multiple cases on the packing case conveyer 400 downstream of the discharge end 103.2 of the compactor apparatus 103. The packing cases 20 shown in figure 10A have a compacted content C.

[ 42 ] Figures 11A and 11 B schematically show a packing case 20 with an uncompacted content C and a compacted content C, respectively, of (yet unfried) frozen French fries that have been provided in a number of perforated bags A. Air is also included into the bags while providing the French fries into the bags and the French fries are not closely packed at that moment. In the compacting process with the compactor apparatus 103, the air is forced out of the perforated bags and the French fries become more aligned parallel with the bottom of the packing case for a more dense filling of the bags. As a result, the content C of bags A with unbaked French fries occupies less volume in the compacted condition of figure 11 B as compared to the uncompacted condition as shown in figure 11 A, and a very efficient filling of the packing cases 20 is achieved. Actually, the whole volume of the packing case is filled, with the aim of no overfilling or underfilling of the packing cases. Figures 11A and 11 B also show a pressing element 315 of a pressing arrangement 310 of the compactor apparatus 103 to assist in compacting the content to a level of a top edge provided by score line 25 of the packing case 20 so that flaps 22 of the packing case can be folded and closed over the content C. Compacting the content allows a much larger amount of product to be filled in the packing case and a much more stable packing case with product filling for handling, transportation and storage purposes.

[ 43 ] The packing case conveyor stretch 400.3 of the packing case conveyor 400 as part of the compactor apparatus 103 has compactor roller bars 320. The compactor roller bars 320 act on the one hand to advance the packing cases 20 along the packing case conveyor 400. On the other hand, the compactor roller bars 320 are shaped to provide a shaking movement to the packing case in the vertical direction while rotating. An example of such shape is shown in figure 10B. The compactor roller bar 320 has a non-circular cross-section perpendicular to its rotation axis 321 . All roller bars 320 of the compactor apparatus 103 act in synchronization to provide the up-and-down shaking movement to the packing cases being supported on the compactor roller bars. Pressing members 315 of a pressing arrangement 310 will exert a downward force onto the content C of the packing cases 20 supported on the compactor roller bars 140 while rotating. This causes the content C to compact from the uncompacted state as is shown in figure 11 A to a compacted state as is shown in figure 11 B. In the embodiment shown, the three pressing members 315 can be collectively moved up and down with respect to frame 317 of the pressing arrangement 310 through actuator 316. The actuator 316 is fixedly mounted on the frame 317, while the pressing members 315 are vertically displaceable with respect to the frame 317 of the pressing arrangement 310.

[ 44 ] In the yet uncompacted state of the content C, the pressing members 315 are lowered onto the content C until the weight of the pressing members 315 is supported by the content C. At that moment, the compactor roller bars 320 are put into rotation, which causes compaction of the content C by the joint action of rotation of the compactor roller bars 320 and the weight of the pressing members 315 on the content C. Reference is made to WO 2019/083360 A1 , which is incorporated by reference into the present disclosure, for a more detailed description of the compactor apparatus shown in figure 10A,

[ 45 ] Figures 11A and 11 B schematically show the compacting of the content C of bags with loose product, being perforated bags with frozen French fries in the embodied disclosed. The content height HC to which the content is compacted may vary over time. When the loose product is a product like frozen French fries, the water content will vary during the season, which will cause a varying content height HC during the season. A feedback from the compactor apparatus 103 is used in setting the predetermined packing case height in the embodiment disclosed when it is determined that the content height HC has changed. For that purpose the height of the content in the packing case during compacting is monitored as is shown in figure 12.

[ 46 ] Figure 12 schematically shows the height h of the content in the packing cases 20 as a function of time t during the compacting process. At time t=0 the pressing members 315 have been lowered onto the content C and the compacting roller bars 320 are put into rotation. The height of the content C during compacting from an initial height hO at the start at t=0 will follow a curve, of which the fall-off value hi after a characteristic time t1 will be a measure for the final content height HC. Therefore, the fall-off value hi can be used for determining the content height HC and the predetermined packing case height for a next batch of filling packing cases with content, as is done in the embodiment shown. The height is measured by having appropriate sensors 325 (only generally indicated) measuring the position of the pressing members 315 with respect to frame 317 of the pressing arrangement 310. In this fashion one can monitor the compacted content height HC over time, for instance, during the season when the water content of French fries will change, and adapt the predetermined packing case height to the changed content height, if required. This can be continuously carried out during the packing process, especially when such packing line runs day after day. The predetermined packing case height can be adjusted at any moment when it is deemed required, based on the continuously monitored content height HC. The packing case height can be set before each batch of packing cases being processed so that case heights of packing cases in one batch are identical for efficient stacking of the packing cases of the batch. A batch can be defined as a number of cases to be put on a single pallet, that are part of a single shipment, etc. A batch can be defined in various manners and may refer to number of packing cases that are similar in time or space. The case height setting step may be executed when a height of the content as determined in the content height determining step has changed more than a predetermined amount as compared to a height of the content as determined for executing a last case height setting step.

[ 47 ] The content height measurement and determination can be done, for instance, for all packing cases (cycle of erecting, filling and closing a packing case), or for a last packing case, or for every n ^th packing case (n being an integer number) in a batch to set a new packing case height for a next batch. The case height setting step is repeatedly executed and is each time subsequently followed by one or more successive cycles of subsequent case erecting, case filling and case closing steps. Generally, the number of successive cycles after setting a packing case height is at least two.

[ 48 ] Alternatively, or when a packing line has not been operated for some time, the step of determining the height HC of the content can be executed during one or more separate steps of filling a packing case, or a partially erected preform corresponding to the packing case with an open second side, with the content provided therein. This determination of the height HC of the content can then be used for the step of setting the predetermined packing case height for one or more successive cycles of the steps of erecting, filling and closing the packing cases.