The invention relates to a separating device for separating individual container products from a frame assembly which consists of a plastic material, particularly of polypropylene, having at least one stamping device which at least partially separates the respective container product from the frame waste.
The prior art (DE 199 26 329 A1) discloses methods and devices for producing container products of plastic, as they are supplied to a generic separating device which is used for separation of the pertinent individual container products from a frame assembly using a cutting or stamping device. To produce the respective container product, a tube of plasticized plastic material is extruded into a molding device, one end of the tube is sealed by welding and it is widened by producing a pneumatic pressure gradient which acts on the tube, and to form the container is applied to the molding wall of the molding device consisting of two opposite molding tools. By way of a corresponding filling mandrel the plastic container then is filled under sterile conditions within the molding device and, after removal of the filling mandrel, it is then hermetically sealed with the formation of a definable head geometry for forming the actual plastic container in which the fluid is later stored, two container shaping jaws can be moved toward one another by hydraulic driving means for obtaining the closed position and can be moved away from one another in opposite directions into one of their opening positions. To achieve very high output rates of container products, DE 103 23 335 A1 describes a multi-station arrangement and, by distributing various shaping steps among different stations located in succession on an imaginary arc, a type of carousel arrangement is formed which enables very high cycle frequency for the plastic material to be output in the form of container products.
Since the charge to be added to the respective container product is often very susceptible to ambient media, especially when it is a highly sensitive pharmaceutical, in the prior art the focus is on, for example, covering the fill opening of the container tube at least from its formation to filling of the pertinent container in a sterile space by a sterile barrier, and very good results can be achieved here, when, as shown in DE 10 2004 004 755 A1, a sterile medium is brought by means of the indicated barrier in the direction of the container fill opening using a medium conveyance device in order to further improve sterility. Another or additional measure for increasing sterility simply is to provide higher processing temperatures, for example, in the production of the tubing for the container products or while the charge is being added, an increased processing temperature finding its limits when the often used plastic material, such as polyethylene, is temperature-sensitive, which can be, however, otherwise very easily processed in the pertinent production devices and, accordingly, is preferred.
Otherwise, in addition to atmospheric oxygen, other gases can diffuse later on through the thin polyethylene wall into the interior of the container during the storage and sale of the container product which has been produced under sterile conditions and can damage the sensitive container contents or even make them unusable.
In order to remedy this latter disadvantage, in the prior art, production processes for these container products have already been proposed (DE 103 47 907 A1 and DE 103 47 908 A1), which relate to so-called co-extrusion production processes in which the container is built up from several layers of plastic materials, often at least one of the layers being used as a blocking layer. Here five and more layers, for example, formed from polyethylene and low density polyethylene as well as copolymers (ethylene-vinyl alcohol copolymer) can form the multilayer container wall which in this case then forms an effective blocking layer; however, these processes are costly in practical implementation. This makes the respective container product correspondingly more expensive.
If the individual container products come filled from the respective production machine, they are in the form of an ampule block in which several successive ampules or containers have a common wall as a block assembly or frame assembly. In order to detach the containers or ampules from the block assembly or frame assembly, they are cut out or punched out along edge zones, in this case then a certain amount of frame waste being formed which, however, can be recycled using modern techniques. DE-PS 38 31 957 discloses a method of producing plastic hollow container products which are present first as an ampule block or frame assembly, in one edge zone of the frame waste additionally a hollow body being molded; this increases stability in the frame assembly and, among other things, helps facilitate separation from the container product to the frame waste by means of the separating device being used respectively.
Proceeding from this prior art, the object of the invention is to devise a separating device with which, at high speed, the separation of the container products—regardless of the type of plastic material comprising them—from the frame assembly can be achieved and which, in addition to a high degree of operating reliability, also has relatively low production costs. This object is achieved by a separating device with the features of claim 1 in its entirety.
In that, as specified in the characterizing part of claim 1, the stamping device of the separation device has a free fall body which from the initial position in free fall separates the respective frame waste from the respective container product, separation can be effected with very high speed (free fall) and additional mechanical components for applying a positive force to the stamping body in the preparation of the separation line can be omitted. Ultimately the free fall body need only be raised again and again; this, for example, can take place by means of a pneumatic working cylinder. This proceeds quickly as well and requires little energy.
In particular, it has been shown that with the separating device according to the invention, polypropylene as the wall material can be used for container products; a plastic material which is rather brittle compared to polyethylene material and which can be worked only with difficulty using conventional stamping and cutting means for container separation. If conventional separating devices are used, it has been found that with respect to the very high processing temperatures of polypropylene, it would be necessary to wait several minutes until the stamping or cutting process is possible at all. But this necessarily leads to the requirement of very long retaining distances and/or additional cooling means for the container products to be separated in order to be able to effect separation without waste at all. As a result of the free fall body of the stamping device, clean separation can take place without these waiting times or ancillary cooling means; this is done by the respective container product being simply knocked off the still very warm or hot frame assembly with high speed by way of the free fall body with its projecting stamping surfaces. For one with average skill in the art in the field of such separating devices it is surprising that with relatively bluntly kept stamping cutting edges which need not be further worked (ground) or maintained, he arrives at separating stamping lines which are clean; this was not possible using the means in the prior art.
The advantage of using polypropylene material instead of polyethylene or a coextruded multilayer composite consisting of LDPE/MDPE is that the polypropylene material can be autoclaved at high temperatures (121° C.), and the polypropylene material from only one extrusion head can be obtained at a much lower cost than the described multilayer systems. Thus, ultimately any individual layer to be produced in a multilayer system requires it own extrusion head in the production machine; this increases production cost accordingly in terms of the control side as well.
If the separating device according to the invention with the stamping device and free fall body is used for polypropylene material, this application is not limited thereto. Rather, there are a plurality of possible applications here and the separating device according to the invention can also be used for other plastic materials such as polyethylene or plastic multilayer systems for separation of a container product as necessary.
In one especially preferred embodiment of the separating device according to the invention, the card-shaped frame assembly with the individual container products provides for division into a head part and bottom part, each of the pertinent parts being assigned its own stamping device which are arranged in succession along a transport line for the frame assembly. The individual separation of the head part and bottom part allows even large format cards of the frame assembly to be “worked” with the separating device and cutting allows the respective mass of the free fall body of the stamping device to be reduced. Another advantage in separation consists in keeping the stamping device for the head part unchanged for each frame assembly size and the stamping device for the respective bottom part of the frame assembly is changed depending on how large the ampule body is in terms of its length depending on the amount of fluid to be held. In this way, adjustment efforts for the separating device can be reduced if different types or quantities of container products are to be separated from the frame waste using the separating device. Of course, the base part can also be retained and the head part changed if this is necessary.
Advantageously, the material flow for the card-like frame assembly (ampule block) to the respective stamping device is improved by way of transfer devices located in succession in the transport line in addition to at least one pivoting means and in this way the output rate for the separating device is increased.
Other advantageous embodiments of the separating device according to the invention are the subject matter of the other dependent claims.
The separating device according to the invention is detailed below using one embodiment as shown in the drawings. The figures are schematic and not to scale.
FIG. 1 shows a frame assembly given in a face-side top view, consisting of the actual ampule block and the frame waste;
FIG. 2 shows an ampule block removed from the frame waste, in which the individual container products with intermediate wall webs are detachably connected to one another as a commercial unit;
FIG. 3 shows in a top view a schematic of the transport line or conveyor line for the ampules or containers produced by a production machine with the successively arranged stations of the separating device;
FIG. 4 shows a housing arrangement for holding the individual stations as shown in FIG. 3 in a perspective view;
FIG. 5 shows in a face-side view a first transfer means;
FIG. 6 shows in a perspective top view a pivoting means for inserting the container products into a first stamping device;
FIG. 7 shows a partial section of the left-hand support of a frame assembly of the pivoting means, which support is viewed in the direction of looking at FIG. 6;
FIG. 8 shows in a perspective view a module-like first stamping device;
FIG. 9 shows in a perspective view a second form of the transfer means;
FIG. 10 shows in a perspective view the module-like structure of another second stamping device.
The frame assembly 10 shown in the figures consists of a plastic material, in this case, of a polypropylene material. The frame assembly 10 is composed essentially of the actual container products 12 together with the so-called frame waste 14 which is to be separated from the actual container products 12. When the container products 12 are separated from the frame waste 14, an ampule block from which the frame waste 14 has been removed as shown in FIG. 2 results for this purpose, the individual containers or individual ampules being connected to one another by way of the remaining intermediate wall webs 16 of the frame waste 14, the intermediate wall webs 16 making it possible for the respective container product 12 to be separated from the containers which remain in the block in the manner of a twist-off motion.
The respective container product 12 is known in the prior art and the above described ampule block solution is described, for example, in DE 38 31 957 C1. The basic shape shown in FIGS. 1 and 2 constitutes only one type of an embodiment and, in particular, the container geometries can be specified on the user side within a widely drawn scope. To release the container contents, usually in the form of a fluid which has been added beforehand, a twist-off cap 18 is used and it can be separated from the container product otherwise by way of the corresponding scoring via a grip 20, likewise in the manner of a twist-off motion, with the result that the fluid can be removed by way of the cleared container opening. Other container opening solutions such as dropper caps can likewise be implemented.
On the bottom of the frame assembly 10, as shown in FIG. 1, blind holes 22 are made and using pins of a transport means (not shown) which engage the blind holes 22 on the bottom edge of the frame waste 14, the frame assembly 10 consisting of the container products 12 and the frame waste 14 is removed from the tool of a production machine which is not detailed, due to the high stability of the frame waste, owing to a waste edge zone which is self-contained in its form, removal is then reliably and easily possible even when the plastic of the frame assembly 10 has not yet completely cooled. This respective configuration is conventional so that it will not be further detailed here.
As FIG. 1 furthermore shows, the frame waste 14 is divided in two along at least one separating line 24, this division taking place in the production machine which is not shown and the bottom-side frame waste 26 can be removed separately from the head-side frame waste 28 with the result that, in this embodiment, intermediate wall webs 16 between the container products 12 remain with the formation of a retail unit. The illustrated solution can, however, also be modified such that overall the frame waste 14 is removed in such a way that individual container products 12 form the respective retail unit without still being connected to one another. What configuration is chosen here is at the discretion of the user.
FIG. 3 shows, as a schematic and in a top view, the individual stations of the separating device as a whole. Viewed in the direction of looking at FIG. 3, at extreme left, the exit region 30 of a production machine for producing the frame assembly 10 is shown, this production machine, for example, being described in DE 103 23 335 A1 so that it will not be detailed here. A first transfer means 32 which is shown in FIG. 5 in essential outlines retrieves three units as the frame assembly 10 from the production machine at the same time and transports them to a pivoting means 34 as is shown as a whole in FIG. 6.
This pivoting means 34 places the triple frame assembly 10 in a first stamping device 36 as shown in FIG. 8 and by means of this first stamping device 36 the bottom-side frame waste 26 is separated from the respective frame assembly 10. Then the respective frame assembly 10, still consisting of the container products 12 and the head-side frame waste 28, as well as the intermediate wall webs 16 as shown in FIG. 9, is removed by a second transfer means 38 from the first stamping device 36 and supplied to a second stamping device 40, as is detailed in FIG. 10. Instead of the illustrated triple frame assembly 10, individual ampules with the frame waste surrounding them or some other definable number of interconnected ampules could be worked with the separating device according to the invention.
The second stamping device 40 then separates the head-side frame waste 28 from the remaining frame assembly, as described, and the container assembly as shown in FIG. 2 is transferred in turn in the triple arrangement by means of the second transfer means 38 from the second stamping device 40 for further delivery to a removal station 42 (compare FIG. 3). Then the product, which has been obtained in this way, can be placed in conventional packaging for commerce by means of suitable devices (not shown). FIG. 3 therefore shows in rough outlines how the transport line runs, proceeding from the production machine located at left viewed in the direction of looking at FIG. 3 with its output region 30 which is connected to the first stamping device for bottom-side frame waste 26 and then the second stamping device 40 for the head-side frame waste 28. For correspondingly small container products, one stamping device can also be sufficient to separate the frame waste 14 in its entirety from the respective frame assembly 10.
The stamping sequence can also be reversed such that first the head-side frame waste 28 is removed, and then the bottom-side frame waste 26 in the direction of the described transport line; only the embodiment shown in FIG. 3 has the advantage that the length of the container product 12 and therefore the filling volume can be changed without the geometry of the head side of the container product 12 changing, and, of course, then, depending on the ampule length, the first stamping device 36 which is the left one viewed in the direction of looking at FIG. 3 can be changed on the bottom side from its stamping tools. The indicated waste products 26, 28 can be removed from the separating device by way of the corresponding removal bevels 44 on the first stamping device 36 and the second stamping device 40.
This separating device, as illustrated particularly in FIGS. 6, 8, and 10, is made modularly using individual modules 46 which can be easily replaced for maintenance and assembly purposes, and, should a production machine output altered shapes for the frame assembly 10, by the correspondingly modular configuration of the stamping and transfer means and of the pivoting means, adaptation to the altered product can take place. The cabinet-shaped housing structure 48 of the separating device shown in FIG. 4 also takes into account this modular nature and one station is assigned to each easily accessible cabinet part. In order to enable a clear view of the respective station of the separating device, specifically that part of the housing structure 48 which is the top part, viewed in the direction of looking at FIG. 4, can have glass wall segments 50.
The respective stamping device as shown in FIGS. 8 and 10 each has a respective free fall body 52 which is intended to have a high free fall mass, for example, on the order of fifty and more kilograms. On the bottom of the respective free fall body 52 are strip-shaped separating bodies (not shown) which are kept relatively blunt and which separate the frame waste 14 from the actual container products 12 in the indicated two steps. Viewed in the direction of looking at FIGS. 8 and 10, the free fall body 52 there is shown in its upper initial position and is able to fall vertically from its initial position into the separating or stamping position, viewed in the direction of looking at the figures. A lifting means 54, for example, in the form of a pneumatic cylinder, is then in turn able to quickly retrieve the fallen free fall body 52 from the stamping or separating position into the initial position shown in FIGS. 8 and 10. For this purpose, the free fall body 52 is coupled to a falling plate 56 on which the pneumatic cylinder acts with its piston rod.
As FIGS. 8 and 10 furthermore show, the respective stamping device 36, 40 is provided with an angle-shaped base body 58 along whose horizontally arranged base part 60 the respective frame assembly 10 is guided and extends parallel to the free fall body 52 which is guided via at least one lengthwise guide 62 on the vertically running guide part of the base body 58. The respective base part 60 of the stamping devices 36 and 40 each has individual receivers 64 for three ampule block arrangements to be held at a time. The respective individual receiver 64 of the first stamping device 36 as shown in FIG. 8 is designed such that the container products 12 on their head part are held with the twist-off closure in the individual receiver 64 and, in the region of the actual container with the contained fluid as shown in FIG. 1, the bottom-side frame waste 26 can be removed.
In the other stamping device 40 as shown in FIG. 10, the conditions are reversed and the container product 12 is then held in the region of the actual container receiver and, in the head-side region, the respective container product 12 is guided in the individual receiver 64 such that the separating body of the free fall body 52 can remove the head-side frame waste 28. In correspondence with the number of container products 12 in the frame assembly 10, in this embodiment there are always five pressure pads on the head or bottom side for the individual receiver 64. The individual receivers 64 can be easily replaced so that any machine downtimes can be kept short for modification measures or in case of wear.
In order to be able to ensure material transport within the transport line, as already shown, different types of transfer and pivoting means are used. The transfer means which are shown in FIGS. 5 and 9 and which once vertically transport the respective frame assembly 10 and then horizontally transport the at least partially stamped out ampule block, are of conventional design and are not detailed here for that reason. The first transfer means 32 as shown in FIG. 5 retrieves the respective frame assembly product 10 which has been completed by the production machine and moves it to the pivoting means 34 as shown in FIG. 6. There the product blocks 10 which have been transported by the first transfer means 32 are transferred to the pivoting means 34 and two pivotable frame parts 66 and 68 clamp the respective frame assembly 10 securely between each other and are transferred, in this case, viewed in the direction of looking at FIG. 5, from the first transfer means 32 in the right travelling position, the simultaneously shown left travelling position corresponding to the removal mode on the production machine.
To insert the respective frame assembly 10 into the assignable individual receivers 64 of the first stamping device 36, with the individual working cylinder 70, which is the lower one viewed in the direction of looking at FIG. 6, the frame parts 66 and 68 can be jointly moved horizontally in order in this way to execute a horizontal feed motion to the first stamping device 36. Furthermore, the two frame parts 66, 68 with the frame assembly parts clamped between them can be moved out of the acceptance position which is vertical when viewed in the direction of looking at FIG. 6 by means of two pivoting cylinders into the horizontal insertion position in which the respective frame assembly 10 is then inserted into the assignable individual receiver 64.
If the respective pivoting cylinder 72 is then retracted, the frame part arrangement 66, 68 viewed in the direction of looking at FIG. 6 is moved clockwise around the pivoting axis 76 by way of one offset pivoting lever 74 which can be assigned at a time. When the frame part 68 at least comes to rest in its horizontal position within the first stamping device 36, the overlying frame part 66 must be pivoted back counterclockwise in order in this way to release the respective frame assembly 10 in the first stamping device 36 for free fall motion of the free fall body 52 with the stamping device strips located right at the bottom. For the pertinent resetting motion there are three working cylinders 78 and they act on a common connecting rod 80 which passes on the edge side into one transverse connecting rod 82 at a time which, thus intermeshing with teeth 84 (FIG. 7), engages a gear arrangement 86 which, regardless of the actuating state of the pivoting axis 76, allows the frame part 66 located right at the front, viewed in the direction of looking at FIG. 6, to pivot back.
For the feed motion of the frame part 66 to the vertically positioned frame part 68 as shown in FIG. 6, in order to clamp the frame assembly which has been delivered with the first transfer means 32 in a triple arrangement, the working cylinders 78 jointly retract and the frame part 66 is thus pivoted counterclockwise in the direction of the frame part 68. In the process, the common connecting rod 80 to which the working cylinders 78 are coupled on the face side with their actuating pistons entrains the two transverse connecting rods 82 which are located at a right angle on the edge side and which when viewed in the direction of looking at FIG. 7 are extended perpendicular to the plane of the figure in the direction of the viewer and, in doing so, entrain the gear arrangement 86 clockwise in the pivoting direction. In the extension motion of the individual working cylinders 78, the frame part 66 is folded back against the aforementioned pivoting direction and, accordingly, counterclockwise in the direction of the connecting rod 80 which runs transversely thereto. Furthermore, as shown in FIG. 6, there are damper elements 88 on the frame part 66 which damp the striking of the frame part 66 against frame part 68 and form a type of gap boundary for the clamping head-side receiver of the respective frame assembly 10.
With simultaneous retraction motion of the working cylinders 78 and of the pivoting cylinders 72, the two frame parts 66, 68 then move clockwise clamped to one another toward the first stamping device 36 for the transfer process, and the pertinent pivoting transfer motion can still be coupled to the axial lengthwise travelling motion of the overall carriage or frame arrangement by way of the individual working cylinder 70 which then travels in the direction of the first stamping device 36. Essentially, FIG. 7 shows a lengthwise section through the receiving block 90 which is the left one viewed in the direction of looking at FIG. 6 and which, in addition to the pivoting axis 76, also holds the gear arrangement 86 along with the transverse connecting rod 76 and on the lower base end separates the two frame parts 66, 68 from one another. The gear arrangement 86 is pivotally guided in the receiving block 90 as a pivoting sleeve and is firmly connected to the frame part 66.
The second transfer means 38 shown in FIG. 9 then retrieves from the first stamping device 36, as shown in FIG. 8, the remaining frame assembly 10 from which in this case the bottom side frame waste 26 has been removed, and inserts the pertinent parts into the assignable individual receivers 64 of the second stamping device 40 in which then the head-side frame waste 28 is removed. In the next transfer step then the finished container products 12 connected by way of intermediate wall webs 16 are deposited in the removal station 42 for packaging delivery and at the same time a new frame assembly 10 in a triple arrangement is retrieved again and the bottom-side frame waste 26 is removed from it. The second transfer means 38 as shown in FIG. 9, accordingly, works in the manner of a two-cycle arrangement with simultaneous operation of several stations.
With the separating device according to the invention, due to the modular structure, a good spatial situation arises for use of diverse transfer and pivoting means for individual stamping machines. Due to the modular nature, simple retrofitting is achieved by clear separation of standard parts and format parts and there remains enough space for additional options to further expand the separating device or to be able to adapt it suitably within production lines.
Patent Application
20100139468
