System and method for combined connection of at least two plastics material layers

Abstract

The invention relates to a system and a method for the combined connection of at least two plastics material layers and of at least one connecting element to the at least two layers in order to manufacture medical bags.

Description

[0001] Device and method for the combined joining of at least two layers of a plastic material

[0002] Description

[0003] Technical area

[0004] A device and a method for the combined connection of at least two layers of a plastic material and at least one connecting element with the at least two layers for the production of medical bags are described.

[0005] background

[0006] Medical bags are typically made from two layers of plastic film, either by joining two films together or by folding one film over at one edge and joining it at the opposite side. The plastic films can be made of a single material or a composite layer made up of multiple films or layers. The joining is typically achieved by welding the layers together at a joining area. A joining area, for example, forms an edge connection for the bag being manufactured.

[0007] Currently, however, the production of a medical bag requires multiple welding steps to perform at least a partial circumferential weld, as well as a port weld and / or a peel seam weld. These welding steps typically require different parameters, and therefore separate welding stations are used. While there are applications where multiple welding operations are performed in one station, compromises must be made regarding the parameters, particularly the temperature. This means that the resulting joints often have disadvantages and represent weak points in medical bags. The scrap rate is increased in this case.

[0008] A device for welding at different temperatures during the formation of bags is known, for example, from US 2004 / 0123883 A1, which describes the design of heat-sealing jaws that include a seal for an edge of a bag. To carry out the sealing, the heat-sealing jaws each comprise heating zones that are independently controlled to generate a different heat-sealing temperature in a region of the seal between two bag wall sections and the seal between the bag wall sections and a tube segment. For this purpose, insulating air pockets are provided around the jaw section, which accommodates a central heating element for sealing the bag wall sections to the tube segment. The central jaw section can then be heated to a higher temperature in the region of the seal between the bag wall sections and the tube segment.

[0009] A disadvantage of the design described in US 2004 / 0123883 A1, however, is that although a temporary temperature difference can be achieved through the air pockets, this temperature difference cannot be maintained permanently because the heating zones are in thermal contact, resulting in an essentially homogeneous temperature distribution after a certain time. It must be taken into account that the temperature cannot be increased arbitrarily, as otherwise the parts to be joined would be damaged or even destroyed. Because the heating zones are in thermal contact, there is inevitably always a compromise in the temperature in the heating zones, as described at the beginning, so that the quality of the connections suffers and cannot be achieved at an optimum level.

[0010] Task

[0011] The aim of the invention is to perform port welding, i.e., the connection of a connector to a medical bag, and peripheral welding for a medical bag in one station or tool. In particular, the welding temperature should be individually adjustable to the respective requirements without compromise.

[0012] Solution

[0013] The above-mentioned object is achieved by a device for the combined connection of at least two layers made of a plastic material and at least one connecting element to the at least two layers for the production of medical bags, comprising at least one first connecting region and at least one second connecting region, wherein the device is designed such that in the at least one first connecting region a connection of the at least two layers can be carried out by contact welding, and that in the at least one second connecting region a connection of the at least one connecting element to the at least two layers can be carried out by induction, wherein the tool regions (first connecting region, second connecting region) of at least one tool part can be heated differently.The heating of the at least one second connection region can be carried out by means of induction, wherein the connection of the at least one connecting element is carried out via the at least one second connection region heated in this way.

[0014] This allows different temperatures to be achieved for different requirements. In particular, the required temperatures can be precisely adjusted, thus achieving the optimum result for each specific connection.

[0015] The integration of different welding types in one facility enables the provision of different temperatures on the surfaces of welding faces in the joint areas, with inductive temperature control occurring independently of any basic heating of a tool body. This allows the temperature of at least two joint areas to be adjusted for different requirements (e.g., circumferential welding and peel seam or port welding), with no temperature changes occurring, particularly at the boundary areas between joint areas (temperature gradient essentially equal to zero). The joint areas can always lie within a predetermined temperature range, thus avoiding the need for compromises. In particular, the required temperatures can be specifically adjusted, thus achieving the optimum result for each joint.A simple tool design makes it possible to perform several independent welding operations at a single station. This makes it possible to provide a very simple device in which, for example, at least a first joining area of ​​at least one tool part is brought to a definable temperature, and at least a second joining area of ​​the same tool part is additionally heated by the temperature control device.

[0016] Through active temperature control using different welding methods for the at least one connection area and the at least one second connection area, the corresponding surface temperatures can be regulated. For this purpose, the materials of the connection areas are made of a material that has good thermal conductivity or is inductively heatable.

[0017] In further embodiments, the first connecting region can have at least two tool parts which are movable relative to one another and which have forming surfaces in the region of a circumferential weld seam for a medical bag to be produced, wherein at least the forming surface of one tool part is heatable. The forming surfaces of the tool parts have sections which can be heated to different temperatures in order to provide welding surfaces for different applications. The thermal energy is introduced via the forming surfaces to locally influence the material of the at least two layers. The forming surfaces thus form contact surfaces at which the tool or tool parts come into contact with the layers, as well as welding surfaces via which heat is introduced to melt the layers.For this purpose, the device can have two tool parts that have forming surfaces on opposite surfaces, whereby the energy input required to join the layers can only be introduced via one tool part. In further embodiments, both tool parts can also introduce the required energy into the at least two connecting areas (first connecting area, second connecting area) through differently heated or tempered sections of the forming surfaces. In still further embodiments, the temperature of the forming surfaces in the connecting areas can be controlled differently via just one tool part. The other tool part can not be operated on its forming surface or can, for example, only actively be operated in a first temperature or a second temperature range. For example, temperature control in at least one connecting area can take place analogously to the opposite section of the forming surfaces of the other tool part.

[0018] The energy input can also be influenced by the thermal conductivity of the tool component material. For example, a higher energy input may be necessary if the tool component material in one joining section has better thermal conductivity than the tool component material in the other joining section, because the thermal energy "dissipates" more quickly.

[0019] In further embodiments, the forming surface of at least one tool part can be electrically heated. In particular, the forming surface in the first joining area can be electrically heated. In further embodiments, a basic heating for a second joining area can be achieved via electrical heating, with the required second welding temperature in the second joining area being generated by induction.

[0020] In further designs, a controllable heating device can be provided so that the surface temperature can be adjusted. This allows adjustments to be made if a change is required regarding the material to be joined (plastic material, layer structure, etc.) and / or a correction is necessary because the joining result deviates from a specified tolerance range. For this purpose, an additional station or inspection device can be provided that checks the welded joints (e.g., circumferential welding, peel seam welding, port welding, etc.) (visually, mechanically, electrically, etc.).

[0021] In further embodiments, the heating device can be or comprise an electrical resistance heating device, which allows a very precise surface temperature to be set on heat-conducting surfaces.

[0022] In further embodiments, the second connection region for connecting at least one connecting element between the layers can have at least one insert that can be heated by an inductor arrangement, and wherein the at least one insert is decoupled from the forming surfaces in the first connection region. The insert consists of a material that can be heated by induction, wherein adjacent regions of the device that are not located in the connection region and do not form forming surfaces can be made of a material that cannot be heated by induction or that can only be heated to a lesser extent. Thus, heating by induction to achieve a second welding temperature is provided specifically by the at least one insert in the second connection region.

[0023] In further embodiments, an air gap can exist between the at least one insert and the forming surfaces, or a thermal insulator can be arranged so that the heat introduced into the at least one insert in the at least one second connecting region by means of induction does not lead to heating of the forming surfaces of the at least one first connecting region. The at least one insert is thus decoupled from the forming surfaces of the at least one first connecting region. In further embodiments, the inductor arrangement can have at least one inductor (e.g. made of copper) which is guided through at least one tool part in the region of the at least one insert. The at least one inductor is therefore preferably not guided through regions of the device that are not to be heated by induction.Preferably, the at least one inductor can be guided in a component (inductor receptacle) that is itself not inductively heatable and has poor thermal conductivity properties. In further embodiments, the inductor can be thermally insulated from the surrounding material in the areas where it is guided within the device. In yet further embodiments, the inductor can be shielded in areas of the device where no inductive heating is to occur.

[0024] A fluid (e.g. water) can flow through the inductor to cool the material of the inductor itself.

[0025] In further embodiments, the two tool parts can each have an insert in the area of ​​the at least one connection, which together form a closed insert when the two tool parts are closed, so that the heat effect is improved.

[0026] In further embodiments, at least one tool part in the area of ​​the insert can have at least one heat-conducting element, for example made of copper (e.g. copper rods), which preferably runs parallel to the longitudinal direction of the insert and which improves the thermal conductivity in the area of ​​the insert.

[0027] In further embodiments, at least one tool part in the region of the insert can have at least one air gap or an insulator, which preferably runs parallel to the longitudinal direction of the insert in order to provide thermal decoupling from adjacent regions.

[0028] In further embodiments, the diameter, cross-section, and distance to the inductor and / or to the insert of at least one heat-conducting element and / or an air gap and / or an insulator can vary with respect to the surface of the insert and its position relative thereto. In further embodiments, the insert can be made of different metals than the material of the tool parts and / or have special geometries to achieve better inductively induced heating than the material of the tool parts.

[0029] The above-mentioned object is also achieved by a method for the combined connection of at least two layers of a plastic material and at least one connection element to the at least two layers for the production of medical bags using a device according to one of the above embodiments, wherein the first connection region for contact welding in a peripheral region between the two layers is brought to a substantially constant first temperature range and the second connection region for the connection of at least one connection between the at least two layers is brought to a second temperature range, wherein the first temperature range and the second temperature range are different from one another.

[0030] Inductive heating makes it possible to generate temperatures for welding locally in the second connection area, whereby no heating processes need to be taken into account and the heating can only be applied temporarily.

[0031] In further embodiments, the second temperature range can be higher than the first temperature range, so that especially components with high temperatures can be welded to the layers of plastic material over this.

[0032] In further designs, the second connection area can be brought to the second temperature range permanently or intermittently.

[0033] Further features, embodiments and advantages emerge from the following presentation of embodiments with reference to the figures.

[0034] Short description of the characters

[0035] In the drawings shows:

[0036] Fig. 1 is a schematic representation of a tool part of a device for combined welding; Fig. 2 is a further schematic representation of the tool part of a device for combined welding from Fig. 1;

[0037] Fig. 3 is a perspective view of a tool part of a device in a schematic representation;

[0038] Fig. 4 is a schematic representation of an insert for a tool part of a device;

[0039] Fig. 5 is a schematic representation of an insert for a tool part of a device in a further embodiment; and

[0040] Fig. 6 is a schematic representation of a method for combined welding.

[0041] Detailed description of implementation examples

[0042] Below, exemplary embodiments of the technical teaching described herein are presented with reference to the figures. The same reference numerals are used for identical components, parts, and processes in the description of the figures. Components, parts, and processes that are not essential to the technical teaching disclosed herein or that would be obvious to a person skilled in the art are not explicitly shown. Features stated in the singular are also included in the plural, unless explicitly stated otherwise. This applies in particular to statements such as "a" or "an."

[0043] The drawings show various embodiments of a device 100 for combined connection and components thereof.

[0044] Fig. 1 shows a schematic representation of a lower tool part 110 of a welding tool for combined welding, which is a component of a device 100. The device 100 can be a component of a welding station of a system for producing medical bags. In particular, Fig. 1 shows the design of a tool part 110 for the combined welding of films for the production of medical bags, wherein a circumferential weld for the edge of a medical bag and a port weld of connecting elements (ports, tube pieces, etc.) can be produced jointly and simultaneously. Fig. 1 shows one possible embodiment, which in further versions can have additional components or other configurations.

[0045] The device 100 for the combined joining of at least two layers made of a plastic material (e.g., EVA, PVC, PE, PP) and at least one connecting element to the at least two layers for the production of medical bags has at least one first joining region 116 and at least one second joining region 142. The device 100 is configured to join the at least two layers by contact welding in the at least one first joining region 116, and to join the at least one connecting element to the at least two layers by induction in the at least one second joining region 142. Different temperatures can be achieved at first welding surfaces 117 in the first joining region 116 and at second welding surfaces 144 in the second joining region 142 through the different welding types.

[0046] The layers can have several layers, which consist of the same and / or different materials and can have a different layer thickness from each other.

[0047] Fig. 1 shows a tool part 110 for a head region of a medical bag, in which connecting elements 192 (see, for example, Fig. 4) with the layers 192 made of a plastic material are introduced and the layers 192 are connected to one another in a peripheral region. The illustrated tool part 110 has a tool body 112 made of a material with high thermal conductivity properties. The tool body 112 can, for example, be made of aluminum or an aluminum alloy. The tool body 112 has first connecting regions 116 with first welding surfaces 117, which are designed to form the peripheral weld seam for a medical bag and to form chambers (as can be seen in Fig. 2) surrounded by the seam. The tool body 112 has two receptacles 114, in each of which an inductor receptacle 120 is inserted. The inductor holder 120 serves to hold an inductor 170, which is guided through a receiving opening 122.The inductor receptacle 120 has a receptacle region 146 at its upper end, shown in Fig. 1, into which an insert 140 is inserted. The inductor receptacle 120 can be made of a different material than the tool body 112 and can have poorer thermal conduction properties than the tool body 112. In the exemplary embodiment shown, the inductor receptacles 120 have an air gap 118 on the sides opposite the tool body 112. On the underside, the inductor receptacles 120 have an air gap 119 opposite the tool body 112 and are only in contact with the tool body 112 via feet 124. This minimizes heat transfer between the tool body 112 and the inductor receptacles 120 in both directions. This applies to both heat dissipation (cooling) and heat input (heating).In further embodiments, thermal insulators can be used instead of air gaps 118, 119 and arranged between the inductor receptacles 120 and the adjacent walls of the receptacles 114. In this case, the formation of feet 124 or the like can be omitted, so that there is no direct contact between the tool body 112 and the inductor receptacle 120, which further improves thermal insulation.

[0048] A lower tool part 110 can have additional first welding surfaces 117 for forming a circumferential weld seam, which are not shown in Fig. 1 and represent an extension of the first connecting regions 116 for producing a circumferential weld seam for an edge of a medical bag. In further embodiments, an additional lower tool part can be connected to the tool part 110 shown in Fig. 1 for a circumferential weld seam. Thus, a circumferential weld seam can be provided via the lower tool parts.

[0049] In the exemplary embodiment of Fig. 1, the first connecting regions 116 for the circumferential weld seam are interrupted by the second connecting regions 142. The tool body 112 and the first welding surfaces 117 can be brought to an adjustable temperature using a heating device. The surface temperature at the first welding surfaces 117 can thus be adjusted using the heating device. The first welding surfaces 117 protrude from the rest of the tool body 112 so that, in interaction with a second tool part 180, an outer circumferential seam for a medical bag is created only in the region of the first connecting sections 116 or first welding surfaces 117, wherein the material for the medical bag only comes into contact with the tool body 112 in the region of the first welding surfaces 117 to create a circumferential weld seam. Fig. 2 shows a further schematic representation of the tool part 110 for the combined welding of Fig.1 in perspective view. The view in Fig. 2 shows the formation of the welding surfaces 117 for the chambers. In a medical bag, the chambers can be provided with an embossing and / or an opening in further processing steps.

[0050] In the exemplary embodiments shown in the figures, the inserts 140 are shell-like. The shells have a semi-cylindrical shape and are made of an inductively heatable material. The inserts 140 can be made, for example, of iron, a steel alloy, precious metal, aluminum, titanium, copper alloys, carbon fiber, or graphite. By controlling the current flowing through the inductor 170, the magnetic field generated thereby can be regulated. This allows the heating of the insert 140 to be controlled, enabling very precise heating of the material of the insert 140. For example, for inductive heating of aluminum, temperatures in the range of 450°C to 580°C can be achieved. For connecting connecting elements to the layers of a medical bag, temperatures in the range of 140 to 230°C, in particular 160 to 200°C, preferably approximately 180°C, can be achieved.Advantageously, the temperatures in the inserts 140 can be adjusted very precisely by induction, so that the required heat energy for connecting connecting elements to the layers is always achieved. Furthermore, the temperature can be reached quickly, for example, within a few seconds, without a time-consuming preheating step of a tool body 112. This allows the energy required for welding to be applied only temporarily, which advantageously means that, for example, high temperatures generated by induction do not prevail permanently and influence the material of the layers to be joined or of the tool body 112.

[0051] Fig. 3 shows a perspective view of a tool part 110 of a device 100 in a schematic representation. The embodiment has a lower tool part 110, which is designed as shown in Figs. 1 and 2. The device 100 further has a frame 160. Two holders 162, which have ports for receiving connection elements (here, ports), are arranged on the frame 160. The ports are pushed onto the holders 162 for a connection between the layers made of a plastic material and are pushed between the layers in the second connecting regions 142. A second tool part 180 is then moved relative to the first tool part 110 so that the layers can be welded to one another in the connecting regions 116 and the connection elements can be welded to the layers in the connecting regions 142.In the closed state, opposing welding surfaces 117 in the first connection areas 116 press against the layers and, under the influence of heat, form a circumferential seam. In the closed state (see Fig. 4), the inserts 140 in the second connection areas 142 press the layers from the outside against the connecting elements, which are pushed onto the holders 162.

[0052] The layers are joined together between the welding surfaces 117 by so-called thermal contact welding, whereby the thermal energy from the tool body 112 causes local melting and thus bonding of the layers through the contact of the plastic material of the layers with the welding surfaces 117. In the second connection areas 142, melting and bonding of the layers to the connecting elements is achieved by inductive heating of the inserts 140. For the connection of the connecting elements to the layers, a higher temperature is required in the second connection areas 142 than in the first connection areas 116 because the introduced heat "flows away" via the holders 162, which are generally made of a metal or metal alloy and thus have relatively good thermal conductivity properties.The holders 162 are not actively heated to prevent pushed-on connecting elements from sticking to the holders 162. The holders 162 also serve as cooling elements, so that a higher temperature is required for welding, even if the connecting elements are made of the same material as the layers.

[0053] An inductor is guided through the receiving openings 122 of the inductor receptacles 120, which inductor provides the magnetic field for induction to heat the inserts 140 when current flows through it.

[0054] Fig. 4 shows a schematic representation of an insert 140 for a tool part 110 of a device 100. In Fig. 4, the insert 140 is shown directly in a tool part 110, wherein in further embodiments the embodiments shown can also be provided in an inductor receptacle 120.

[0055] The insert 140 is inserted into a receiving area 146 and is flush with the surface of the adjacent areas. The inductor 170 is arranged in the receiving opening 122 below the shell-like insert 140. The inductor 170 generates an electromagnetic field when a current flows through the inductor 170, thereby heating the insert 140. To improve the heat effect in the area of ​​the insert 140, heat-conducting elements 130 can be inserted into openings 126, which are also heated by the inductor 170. This can provide or support heating of the insert 140 around the insert 140. Heat-conducting elements 130 can be made, for example, of copper or another suitable material, as described above.Additionally, at least one further air gap 148 can be provided in a tool body 112 or in an inductor receptacle 120, providing thermal insulation so that the heat introduced into the surrounding material via the insert 140 and / or the heat-conducting elements 130 does not lead to heating of the tool body 112 or the inductor receptacle 120 in the outer regions. Alternatively, the effect of the induced heat can be reduced via an air gap 148. In still further embodiments, a thermal insulator can be inserted in an air gap 148.

[0056] The configuration of the air gap 148 may also include other geometries in further embodiments. Furthermore, the number of openings 126 and the heat-conducting elements 130 inserted therein may differ from the illustrated embodiment.

[0057] Fig. 4 schematically illustrates a second tool part 180. In the closed state of the device 100, the tool parts 180 and 110 lie on top of one another, so that in the second connecting region 142, essentially a closed insert consisting of the two inserts 140 is provided.

[0058] In further embodiments, an inductor receptacle 120 or the air gaps 118 of one of the two tool parts 110, 180 can be offset from the inductor receptacle 120 or the air gaps 118 of the opposite tool part 180, 110, so that the air gaps 118 are not directly opposite each other, which could lead to a weak point in a connection area. The offset can, for example, be less than 1 mm, preferably approximately 0.5 mm, depending on the design and dimensions as well as the materials used (device 100 and layers 192, connection element 190).

[0059] The embodiments shown make it possible to minimize a transition between the first and second connecting regions 116, 142, wherein the welded joints in the first connecting region 116 and in the second connecting region 142 are formed by providing a desired temperature on the welding surfaces 117, 144.

[0060] Fig. 4 shows a section through a connecting element 162, which is pushed onto a holder 162. The connecting element 162 is surrounded in half by a layer 192 of a plastic material in the second connecting region 142 between the inserts 140. Outside the second connecting region 142, the layers 192 lie on top of one another in the first connecting regions 116 and are pressed together via the welding surfaces 117 and opposite forming surfaces of the second tool part 180.

[0061] Fig. 5 shows a schematic representation of an insert 140 for a tool part 110 of a device 100 in a further embodiment, as shown in Figs. 1 and 2. In this embodiment, the heat-conducting elements 130 have a shape adapted to the shape of the insert 140, so that the heat input is further improved.

[0062] In an embodiment according to Fig. 5, an air gap 118 exists between the inductor holder 120 and the tool body 112 between the first connection areas 116 and the second connection area 142, thus providing a clear demarcation for the different welds produced. This reduces the transition area to an absolute minimum, for example, less than 0.5 mm. In contrast, the transitions in prior art welds range from several millimeters to centimeters.

[0063] The design of the tool parts 110, 180 makes it possible to adapt the temperatures to the respective sub-area or joining area 116, 142 of the welding task. Therefore, no compromise temperature adjustment is necessary for the different sub-areas or joining areas 116, 142.

[0064] Fig. 6 shows a schematic representation of a method 200 for combined welding.

[0065] In a first step, the device 100, which comprises, for example, a welding tool with at least two tool parts 110 and 180, is opened 210, as described above with reference to Figs. 1 to 5. The opening occurs by relative displacement of the two tool parts 110, 180. In further embodiments, the device 100 can also be opened 210 after a tempering step 220 in order to utilize the thermal influence of the two tool parts during a warm-up phase. In a warm-up phase, at least the tool body 112 of a first tool part 110 can be brought to a first temperature so that the first welding surfaces 117 in first connection regions 116 are brought to the required welding temperature.Depending on the design and mass of the tool body 112, it may exhibit very sluggish behavior with regard to the heating process in the warm-up phase, so that a warm-up phase may last from several minutes to one hour.

[0066] Subsequently, a tempering 220 of the device 100 and in particular of the tool body 112, for example of the lower tool part 110, an upper tool part 180 or both tool parts 110, 180, can take place. In this case, at least the first welding surfaces 117 in first connecting sections 116 are brought to a first surface temperature (for example via a heating device). The heating device can be designed, for example, as a resistance heater. Heating elements of the heating device can be located in a lower region of the tool body 112, so that a basic surface heating of the tool body 112 can be provided from below. Due to the design of the tool body 112 and its material properties, the entire tool body 112 can be heated. For example, the

[0067] The tool body 112 is heated to a temperature in the range of 105 to 160 °C, in particular 130 to 150 °C, preferably approximately 140 °C. Thus, after a warm-up phase, a corresponding welding temperature prevails at the welding surfaces 117 in the first connecting sections 116. The same applies in further embodiments to a second tool part 180, which can also be actively heated.

[0068] In a subsequent step, a film composite is inserted 230 between the two tool parts 110, 180. The film composite comprises at least two layers 192 of a film material, which in further embodiments can have a layer structure made of several plastics. Alternatively, a film composite can also be provided by folding over a layer of film material. The film composite can be fed into a welding station with a welding tool in continuous form or as a sheet. In further embodiments, a film composite can be preheated at least in some areas before insertion 230. After the film composite has assumed a defined position between the tool parts 110, 180, the welding tool 100 or the device 100 is closed 240 by relative displacement of the two tool parts 110, 180.

[0069] When the device 100 or the welding tool is closed, a welding 250 of regions of the film composite takes place in first connecting regions 116 at the welding surfaces 117, wherein the layers 192 are joined to one another by the heat introduced via the welding surfaces 117.

[0070] In addition, connection elements 190 are welded in second connection areas 142 via the inserts 140, which form second welding surfaces 144. The heat required for welding is introduced by induction. For this purpose, with the device 100 closed, a current is passed through an inductor 170, which generates an electromagnetic field that, in turn, heats the inserts 140. Depending on the applied voltage and the current flowing through the inductor 170, the heating of the inserts 140 can thus be precisely controlled. Indirect inductive welding 260 of at least one connection element 190 occurs between the layers 192.

[0071] The film composite is welded in the first connection regions 116 at a first welding temperature and in the second connection regions 142 at a second welding temperature, wherein the first welding temperature and the second welding temperature are different from one another. In the embodiments shown, the second welding temperature is higher than the first welding temperature. In still further embodiments, a device 100 can have at least one further connection region, wherein the at least one further connection region can have a different surface temperature than the first connection region 116 and the second connection region 142, as well as from one another, in order to provide a correspondingly adapted welded connection in a film composite.

[0072] Due to the heating of the first connection areas 116 and the active temperature control of the second connection areas 142, the welded joints created in the film composite after welding or in a bag blank can have different configurations. As explained above, however, the connection can be essentially identical, and the temperature differences can arise from heat dissipation, etc., whereby the above-described embodiments do not impose any limitations on the quality of the welded joint.

[0073] After welding 250 and 260, the welding tool or device 100 is opened 270 and then the welded film composite is removed or dispensed 280, which, for example, has a circumferential weld seam and at least one connecting element 190 on a head region of a medical bag.

[0074] After joining, the previously welded areas can be cooled in another tool.

[0075] In further embodiments, a film composite can already be prefabricated to the outer dimensions. In still further embodiments, a device 100 can have additional cutting devices so that a bag blank can be completely or partially separated from a film composite after welding.

[0076] In the technical teaching presented here, a port weld (port as a connection between two layers 192) and the peripheral weld for the layers 192 to be joined can be performed in a device 100 or station, or a welding tool, using precisely separated tool inserts, such as the inductor receptacles 120 shown in Figs. 1 to 5, which are arranged across an air gap in a tool body 112, as well as induction heating of the tool inserts. In particular, the welding temperature can be individually adjusted to the respective requirement (port welding and peripheral welding) without compromise.

[0077] The basic heating of the tool body 112 can be achieved, for example, with a controlled electrical resistance heater. This allows the peripheral welding to be performed at a first temperature within a first temperature range, which depends, for example, on the materials used for the layers 192. The layers 192 typically each have a layer structure made of different plastic films and / or film thicknesses.

[0078] Various connections (ports, valves, etc.) can be inserted between the layers 192. During the connection, the two layers 192 are generally formed by folding over a single layer 192 or by two layers 192 that are brought into contact with one another in a congruent manner, with the layers 192 being opened or kept open in the area for the at least one connection. At least one connection element 190 is then inserted between the layers 192 in this area. This can be done, for example, before insertion into a station or device 100 for connection or in the station or device 100.

[0079] During the connection, two tool parts 110, 180 are then moved towards one another, whereby a circumferential welding of the two layers 192 takes place in the region of the forming surfaces (e.g. welding surfaces 117). For this purpose, in one embodiment, the forming surfaces are brought to the required first temperature (e.g. 150°C for PP) using a controllable electrical resistance heater. The choice of temperatures depends on the material to be joined. At the same time, the connection of the at least one connecting element 190 (port) between the two layers 192 takes place via an induction arrangement in a second connection area 142. The induction arrangement heats inserts 140, which, as in the exemplary embodiments shown in FIG. 1, are designed as half-shells and thus form a quasi-closed insert when the two tool parts 110, 180 are closed.The outer layers of the two layers 192 are in contact with the surface of the inserts 140. The previously inserted connection element 190 runs between the layers 192 in the area of ​​the inserts 140. By means of induction via an inductor 170 which, in the figures, is arranged below the inserts 140 relative to the respective insert half, the inserts 140 are specifically brought to a second temperature (e.g. 180°C for PP), which is higher than the first temperature. This results in a required connection of the connection element 190 between the layers 192, wherein the temperature for the connection of the at least one connection element 190 / port is higher than the temperature for connecting the layers 192 or at least one layer of the layers 192 for connecting them, because connection elements 190 generally require a higher welding temperature. The higher welding temperature is, for example,also required because the holders 162 shown in the figures for the two connecting tubes dissipate heat.

[0080] Thus, for example, a connection may be required at at least two different temperatures, where the melting point of the material is the same. A higher temperature in one area may be necessary, for example, if a relatively large amount of heat is dissipated and thus cannot be used for the actual welding. The inserts 140 for port welding, which typically have a higher temperature, can be heated accordingly, for example, permanently or intermittently using induction. Depending on the material, a preheating step may also be omitted, further simplifying and shortening the manufacturing process.

[0081] The timing of the induction heating can be controlled according to the circumferential welding process or independently. Furthermore, the cyclic heating of the areas can occur simultaneously or staggered with the connection in the circumferential area. However, both connections are advantageously made in one device 100 or in a common welding tool.

[0082] In experiments, for example, medical bags could be welded in a combined device 100 at the circumference and with a tube (port, connection) within one second without a preheating step.

[0083] Via heat-conducting elements 130 (e.g., copper wires or plates) and air gaps 148 at defined positions in at least one tool part 110, 180 and / or an insert 140 (see Figs. 4 and 5), the heat can be distributed evenly around the entire circumference of the inserts 140, thus heating the inserts 140 homogeneously, significantly improving the result and the connection of a connecting element 190. In particular, in designs with a heat-conducting element 130, only one inductor 170 per insert 140 / connecting element 190 may be sufficient. In further designs, with heat-conducting elements 130, only one inductor 170 may be sufficient for multiple inserts 140 and connections to be introduced.

[0084] In the embodiment of Fig. 5, the insert 140 only has direct contact with the tool part 110 via the two feet 124, so that only a very small thermal transition area exists. An air gap 118 exists between the insert 140 and the tool part 110, in particular on the sides. The distance in the area of ​​the feet 124 can be selected to be large enough to limit the heat flow between the insert 140 and the tool part 110 or tool body 112. The feet 124 themselves are designed to withstand a connection pressure when a welding tool is closed in the area of ​​a connection element 190. In still further embodiments, the described technology can be used to combine other connections instead of a circumferential and port (connection) weld, for which purpose an area is subjected to a different temperature in order to achieve a connection with elements made of a different material with a higher or lower melting point.

[0085]

[0086] 100 Setup no first tool part

[0087] 112 tool body

[0088] 114 recording

[0089] 116 first connection area

[0090] 117 Welding surface

[0091] 118 first air gap

[0092] 119 second air gap

[0093] 120 inductor holder

[0094] 122 Recording opening

[0095] 124 feet

[0096] 126 Opening (for heat conducting element 130)

[0097] 130 Heat conducting element

[0098] 140 deployment

[0099] 142 second connection area

[0100] 144 second welding surface

[0101] 146 Recording area (for port etc.)

[0102] 148 air gap

[0103] 160 Frame (part of the equipment 100 or a welding tool / station)

[0104] 162 holders (for tubes / ports)

[0105] 170 Inductor

[0106] 180 second tool part

[0107] 190 connecting element

[0108] 192 Location

[0109] 200 procedures

[0110] 210-280 process steps

Claims

Patent claims 1. Device for the combined connection of at least two layers of a plastic material and at least one connecting element to the at least two layers for the production of medical bags, comprising at least one first connecting region and at least one second connecting region, wherein the device is designed such that in the at least one first connecting region a connection of the at least two layers can be carried out by contact welding, and that in the at least one second connecting region a connection of the at least one connecting element to the at least two layers can be carried out by induction.

2. Device according to claim 1, wherein the first connecting region has at least two tool parts which are movable relative to one another and which have forming surfaces in the region of a circumferential weld seam for a medical bag to be produced, wherein at least the forming surface of one tool part is heatable.

3. Device according to claim 1 or 2, wherein the forming surface of at least one tool part is electrically heatable.

4. Device according to claim 1 to 3, comprising a controllable heating device, preferably an electrical resistance heating device.

5. Device according to one of claims 1 to 4, wherein the second connecting region for the connection of at least one connecting element between the layers has at least one insert which can be heated by an inductor arrangement, and wherein the at least one insert is decoupled from the molding surfaces in the first connecting region.

6. Device according to claim 5, wherein an air gap exists between the at least one insert and the molding surfaces or an insulator is arranged.

7. Device according to claim 5 or 6, wherein the inductor arrangement comprises an inductor which is guided through at least one tool part in the region of the at least one insert.

8. Device according to claim 7, wherein the two tool parts each have an insert in the region of the at least one connection, which together form a closed insert in a closed state of the two tool parts.

9. Device according to claim 7 or 8, wherein at least one tool part in the region of the insert has at least one heat-conducting element, which preferably runs parallel to the longitudinal direction of the insert.

10. Device according to one of claims 7 to 9, wherein at least one tool part in the region of the insert has at least one air gap or an insulator, which preferably runs parallel to the longitudinal direction of the insert.

11. Device according to claim 9 or 10, wherein the diameter, cross-section and distance to the inductor and / or to the insert of at least one heat conducting element and / or an air gap and / or an insulator varies with respect to the surface of the insert and its position thereto.

12. Device according to one of claims 5 to 11, wherein the insert consists of a different metallic material than a tool part of the device.

13. A method for the combined joining of at least two layers of a plastic material and at least one connecting element to the at least two layers for the production of medical bags using a device according to one of claims 1 to 12, wherein the first joining region is brought to a substantially constant first temperature range for contact welding in a peripheral region between the two layers and the second joining region is brought to a second temperature range for the connection of at least one connection between the at least two layers, wherein the first temperature range and the second temperature range are different from one another.

14. The method of claim 13, wherein the second temperature range is higher than the first temperature range.

15. The method according to claim 13 or 14, wherein the second connection region is brought to the second temperature range permanently or intermittently.

Images