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The object of the invention is a device for separating blanks from waste from a die-cut sheet. The device is intended in particular for use in the manufacture of packaging, labels and other paper-based flat products.
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One of the primary methods of separating blanks from waste from a die-cut sheet is manual separation of waste from blanks - the method used at lower production rates and with relatively little waste.
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Blank is understood to be the usable part cut from a die-cut sheet, e.g.: packaging to be folded, leaflet, label, etc.
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Die-cut sheet are obtained after die-cutting on die-cutting machines of the following types: die-cutting press, automatic die-cutting machine, roller die-cutting machine, actuator die-cutting machine. The most common products die-cut on these machines are cardboard boxes, corrugated cardboard boxes, solid cardboard boxes, boxes made of various plastic materials, bottle and drawpiece labels, self-adhesive paper labels, stickers, folders, wrappers, packaging inserts, envelopes, tags, paper bags and other flat products.
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Depending on what product is to be obtained, different ways of separating blanks from waste are used. The way in which the blank is separated from the waste depends on, among other things, the design of the die-cut item, the way the die-cut item(s) is arranged on the format, the number of die-cut blanks on the format, the print run of the die-cut item(s) or the financial possibilities.
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Among the equipment known from the state of the art for separating blanks from waste are cleaning saws which separate margins from blanks from a die-cut sheet, while the rest of the waste is separated by hand. Another piece of equipment is the cleaning table which makes it possible to separate waste from a stack of 8-10 cm sheets. Underneath the stack of sheets, pins corresponding to the shape of the blanks are mounted. These pins push the blank upwards. The cleaning table cannot be used for separating all types of blanks. Another method of separating blanks known in the state of the art is the so-called stripping where waste elements from a die-cut sheet are pushed downwards. This method is mainly used for the removal of internal elements, e.g. packaging windows, back and side margins or elements difficult to remove by hand. The opposite of stripping is the so-called blanking; in this method the usable material is pushed down onto the pallet and the waste is removed. Both methods, i.e. stripping and blanking, are used as sections of automatic die-cutting machines.
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From patent description Pat.214432, there is known an appliance for separating cardboard blanks from a die-cut sheet, having an appliance with upper plungers and a lower appliance positioned below the appliance with upper plungers and comprising a frame with a pair of longitudinal beams, parallel to the direction of placement of the sheet above the lower appliance, and a pair of transverse beams, characterised in the fact that between the transverse beams, there is arranged at least one cutting flat with a plurality of holes, and a plurality of strings, each of which runs between a string catch mounted on one longitudinal beam and a string tensioner mounted on the other longitudinal beam, and is threaded through a hole in at least one cutting flat.
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From the description of
EP0763407A1 , there is known a device for processing semi-finished products, having two longitudinal side strips extending around them and two transverse strips, a front and rear one, separated by intermediate strips. The device consists of a bottom tool in the form of a grid, the rods of which reproduce the perimeter of the blanks, and an upper tool containing pushers, each fixed above a blank, the perimeter of which is repeated but in a slightly smaller scale. The pressure pads are positioned on the tool above the rods, with an arrangement of resilient supports so that each intermediate and side bar is pressed against the accompanying rod during separation of the blanks. At least part of the pressure pads are placed over the longitudinal intermediate strips and the side strips are formed with one or more suction holes connected to a pneumatic vacuum source.
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The equipment known from the state of the art for the production of cardboard packaging, flat cardboard, paper or plastic components is a set of interconnected machines such as: automatic die-cutting machines with cleaning sections; they are usually used for larger-scale production. However, if any of the equipment fails, the whole line is stopped, the equipment is expensive and not viable for smaller scale production. For smaller productions, some of the steps, e.g. the separation of blanks and waste, are done manually. This, in turn, slows down the obtaining of the final product, as manual separation of blanks from waste does not allow multiple sheets to be worked on simultaneously.
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Therefore, the need arose to provide a device for separating blanks from waste from a die-cut sheet which would be a separate device, not connected to the die-cutting machines, and which would speed up the separation process without adversely affecting the quality of the final products obtained.
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The essence of the invention is a device for separating blanks from waste from a die-cut sheet intended in particular for use in the production of flat cardboard, paper, plastic parts consisting of a work table placed on the base of the device characterised in that the device further comprises a tilting front table movably connected to the base, the upper surface of which is at the height of the surface of the work table, moreover, on the work table, a centre beam is movably positioned parallel to the edge of the tilting front table and to a rear beam which is placed behind the centre beam, the movement of the centre beam being in the vertical axis and the movement of rear beam being in the horizontal axis, along the surface of the work table, moreover, above the tilting front table and parallel to the centre beam, a front beam is movably positioned, the movement of the front beam being in the vertical axis and an cover plate is placed on the surface of at least one wall of the beam.
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The front beam is located in a frame attached to a tilting front table.
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The centre beam is located in a frame fixed to the work table and/or to the base of the device.
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The tilting front table is connected by a hinge to the work table and/or the base and its tilting movement is achieved by the movement of hydraulic or pneumatic actuators positioned between the tilting front table and the work table and/or the base of the device and/or between the front beam frame and the centre beam frame.
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On the surface of the work table, there is a longitudinal opening through which the rear beam is connected to the carriage of the linear technology mechanism.
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Preferably, underneath or at the edge of the work table, there is a threaded rod mechanism to the carriage of which the rear beam is attached and which mechanism, through the rotation of the rod, causes the tail beam to move.
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The movement of the front beam and/or centre beam and/or rear beam is automatic.
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The front beam and/or centre beam is rotatable.
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The front beam and/or the centre beam contains on the surface of each of its four walls an cover plate with the shape of a long flat bar or with the shape of part of the material to be separated.
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The cover plate is made of wood-like material and/or plywood and/or OSB and/or plastic and/or rubber and/or metal.
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The wall of the centre beam on the rear beam side and the surface of the rear beam on the centre beam side contain corresponding splines and grooves.
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Up to now, in the state of the art of the device , the die-cutting sections have been adapted to die-cut sheets with margins between the rows of blanks. The device according to the invention makes it possible to separate blanks from waste from a die-cut sheet in which the blanks are pressed together in such a way that the back of the blanks connects to a flap for gluing adjacent blanks in, for example, box blanks.
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This enables significant material savings, as with smaller die-cut formats, by dispensing with the spacing between die-cuts, it is possible to die-cut more blanks, e.g.: an extra row.
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In addition, there are added knives that cut between blanks and beyond the sheet format. With this arrangement, external margins, rows of blanks, and internal margins are formed. In the case of the labels, the arrangement is the same, but there are additional knives added between the blanks and beyond the sheet format. With this arrangement, outer margins, inner margins and a row of blanks are formed. The bridging of the blanking die is also an important element in a die-cut sheet designed in this way. This is intentional damage to the blanking die by either fixing or notching the die. The effect of such bridging on the die-cut format is a catch between the waste elements and the blanks on the die-cut format.
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The separation of blanks from waste from the die-cut sheet on the device according to the invention consists of separating the margins from the blanks and the blanks from the margins.
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The device according to the invention enables semi-automatic separation of blanks from waste from stacked die-cut sheets in an amount comparable to the number of die-cut sheets used on automated machines, since blanks are separated at one time not from several sheets as in manual work known from the state of the art, but from die-cut sheets stacked in a ream, a stack containing many sheets. The device according to the invention makes it possible to replace the manual separation of blanks from waste from a stacked die-cut sheets.
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The front beam used in the device according to the invention is rotatable and preferably incorporates cover plates on its walls. By rotating this bar with the cover plates, the cover plate (its shape) can be selected to hold/press down part of the material to be separated.
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The centre beam in an optional example of the implementation of the invention can be rotatable. This is advantageous for specific packaging, such as packaging with Braille embossing. In this case, cover plate are also used on the walls of the centre beam - a recess/caving can be made in the Braille embossing area of the cover plates so that the pressure of the centre beam does not crush/flatten the embossing.
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In order to describe the device according to the invention and its operation in more detail, the ream, a stack of die-cut sheets constituting the workpiece, is divided into part A, which is the part of the material to be separated - it may be a margin or a blank or a row of blanks - and part B, which is the rest of the workpiece.
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Semi-automatic operation of the device according to the invention is understood to mean that part of the elements of the device according to the invention are controlled automatically (movement of the beams, movement of the front table), while the stacking of the reams, the rotation of the reams during the separation process of part A and part B is performed manually.
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The elements of the mechanism enabling the automatic operation of the parts of the device such as the vertical movement (downwards and upwards) of the front beam and its pressure on the die-cut sheet, the vertical movement of the middle beam and its pressure on the die-cut sheets, the rotational movement of the front and middle beams and the horizontal movement of the rear beam and the pressure on the side of the ream of the die-cut sheets, as well as the movement of the actuators and thus the movement of the front table, are known from the state of the art.
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The invention is shown in preferred embodiments in the drawing, wherein:
fig. 1 shows the device according to the invention in schematic side view; fig. 2 shows the connection of the rear beam to the threaded rod mechanism in side view; fig. 3 shows a top view of the rear beam on the work table surface with the threaded rod mechanism; fig. 4 - fig. 12 individual stages of operation of the device according to the invention; fig. 13 shows a schematic representation of the front table tilt with its offset from the work table, side view, fig. 14 shows a rear beam and a centre beam, the surfaces of which, facing each other, contain corresponding splines and grooves;
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Fig. 1 schematically depicts a device according to the invention, which comprises a work table 6 placed on a base 7 of the device according to the invention, to which base 7 a movably tilting front table 1 is attached by means of hinges. The tilting front table 1 can also be attached via a hinge only to the work table 6 or to the base 7 of the unit. The tilting movement of the front table 1 is caused by pneumatic or hydraulic actuators located on one side to the tilting front table 1 and on the other side to the base 7 of the device.
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The actuators can also be located between the front beam frame and the centre beam frame.
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The top surface of the tilting front table 1 is at the height of the work table surface 6. The tilting front table 1 in the preferable example of the invention can also be moved away from the work table 6 and tilted simultaneously, by means of hinges (offset) and pneumatic or hydraulic actuators (tilt).
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On the work table 6, the centre beam 4 is positioned movably and parallel to each other and to the edge of the tilting front table 1, and behind it the rear beam 5 is positioned.
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Movement of the centre beam 4 takes place in the vertical axis, in a frame 10 fixed to the work table 6 or to the base 7 of the device.
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The movement of the rear beam 5 takes place in the horizontal axis along the surface of the work table 6, on the surface of which there is a longitudinal opening. Rear beam 5 is connected to the carriage of the linear technology mechanism.
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In the embodiment shown, the rear beam 5 is connected to the carriage 9 of the threaded rod mechanism 8 and its longitudinal movement is caused by the rotation of the rod. This mechanism is located under the work table 6 as shown in fig. 2 in schematic side view and fig. 3 in top view.
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Above the tilting front table 1 and parallel to the centre beam 4, a front beam 3 is movably positioned, the movement of the front beam 3 taking place in a vertical axis in a frame 11 attached to the tilting front table 1.
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The front beam 3 has an cover plate 2 on its walls. The cover plate 2 on the front beam 3 has a variable shape depending on the graphic designs to be realised; it can be shaped like a long flat bar or resemble the approximate shape of the ream part of the separable material A. The cover plates 2 are fitted to the four walls of the front beam 3 and can be made of wood-like material, plywood, OSB, etc., plastic, rubber, metal or combined materials. The cover plates 2 hold and compress part of the separable material A.
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The individual components of the device according to the invention have a specific function:
The tilting front table 1 - through a downward tilting movement and/or through a movement that increases the distance between the tilting front table 1 and the work table 6 - enables the separable part A to be separated from the rest of the workpiece B.
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The front beam 3 moves in the frame 11 in a vertical axis and, through a suitably adjusted cover plate 2, holds, compresses a portion of the separable material A. It can rotate around its axis clockwise or anticlockwise.
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The centre beam 4 moves in the frame 10 in the vertical axis, holding/compressing the rest of the workpiece B.
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The rear beam 5 slides along the work table and moves the ream of workpiece along the work table 6 and the tilting front table 1.
The principle of operation of the device according to the invention is shown in figs. 4 - fig. 12
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The simplified drawings of fig. 4.1 (side view) and fig. 4.2 (top view) schematically show the first stage of operation of the device according to the invention. A ream, a stack of die-cut sheets constituting the workpiece (R) consisting of the separable part A and the rest of the workpiece B is manually placed on the work table 6. The rear beam 5 is automatically pushed against the stacked ream. The centre beam 4 and the front beam 3 are automatically lowered (simplified drawing fig. 4.3). Middle beam 4 compresses (holds) the rest of the workpiece B. Front beam 3, together with a suitably fitted cover plate 2, compresses and holds part of the separable material A.
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Then, the tilting movement of the front table 1, schematically illustrated in fig. 5.1 - caused by pneumatic or hydraulic actuators located on one side to the tilting front table 1 and on the other side to the device base 7 or between the front beam frame and the centre beam frame - results in the separation of part A from the rest of the workpiece B. The separation of the separable part A from the rest of the workpiece B takes place along the cutting line between these parts (fig.5.2).
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Figure 5.1 and 5.2 show the separation of the two parts (A and B) from each other. Then the front beam 3 as well as the centre beam 4 are raised and the separable material A is removed manually, as shown in fig. 5.3.
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Depending on the graphic design of the material to be processed, the front beam 3 can be rotated or not. Fig. 6 shows a schematic rotation of the front beam 3 before the next separation step.
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When box or envelope blanks are die-cut, the front beam 3 is rotated due to the different shape of the cover plates 2 which press on the separable part A of the workpiece.
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When e.g. label blanks are die-cut, the front beam 3 does not have to rotate, because the cover plate always has the same shape and is mounted in the same place on the wall of front beam 3.
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After separation of the separable part A, the tilting front table 1 and the front beam 3 return to their original position (fig 7). The device according to the invention performs a cycle of separating the separable part A from the rest of the workpiece B. In order for the next cycle of separable part A from the rest of the workpiece B to occur, the ream of workpiece is rotated manually to separate the next waste from the workpiece (fig. 8).
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A rear beam 5 is automatically pushed against the upturned and placed on the tilting front table 1 and on the work table 6 of the ream R, and another separable part A is separated (fig. 9). The next steps are repeated, i.e. raising the front beam 3 and centre beam 4 and returning the tilting work table 1.
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In the case of box blanks, in the next step the ream R is turned in such a way as to separate the next waste from blank - as shown in figs. 10 and fig. 11. And in the next stage, the blank is separated in the form of box blank (fig. 12). The successive cycles of separating the separating part A from the rest of the workpiece B do not differ from each other and the end occurs when all the blanks have been separated from the workpiece.
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An optional embodiment of the device according to the invention is a device in which the tilting front table 1 during separation of the separable part A is additionally moved away from the work table 6 by means of actuators (hydraulic or pneumatic) as schematically illustrated in fig. 13.
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Another embodiment a device according to the invention is a device with a rotating centre beam 4 containing cover plates on its walls.
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The example of the invention illustrated in fig. 14, in turn, contains a rear beam and a centre beam, the surfaces of which, facing each other, contain corresponding splines and grooves. This allows bringing the rear beam closer to the centre beam 4.