System and method for manufacturing medical bags

Abstract

The invention relates to a device and a method for manufacturing medical bags.

Description

[0001] Apparatus and method for manufacturing medical bags

[0002] Description

[0003] Technical area

[0004] A device and a method for producing medical bags are described, which have at least two layers of a plastic material, wherein the at least two layers are welded together.

[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 rejection 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 present task is to perform two or more welding operations in a single station, eliminating the disadvantages of the state of the art and significantly simplifying production. 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 producing medical bags, such bags having at least two layers of a plastic material, with at least one welding device which is designed to form at least one first connection on a medical bag by tempering at least a first section of at least one tool part in a first temperature range, and at least one tempering device which is designed to bring at least a second section of the at least one tool part to a second temperature range which is different from the first temperature range.

[0014] The device enables different temperatures to be set for different requirements (e.g. circumferential welding and peel seam or port welding) on ​​a tool part by actively controlling the temperature of at least one section. In particular, no temperature changes occur at the border areas between the sections (no local temperature gradient). The sections can lie within a predetermined range, whereby no compromises have to be made. In particular, the required temperatures can be set specifically, thus achieving the optimum result for the respective joint. A simple tool design makes it possible to carry out several independent welding operations at one station. This makes it possible to provide a very simple device in which, for example,At least a first section of at least one tool part is brought to a determinable temperature, and at least a second section of the same tool part is additionally heated or cooled by the temperature control device. Temperature control within the scope of the disclosed technical teaching refers to both a positive and a negative temperature change.

[0015] By actively controlling the temperature of at least one section and at least one second section, the corresponding surface temperatures of at least one tool part can be regulated.

[0016] In further embodiments, the device can have at least two tool parts which are movable relative to one another and which have forming surfaces or contact / welding surfaces in the at least one first section 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 surface of the at least one tool part has at least a first section and at least one second section 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 therefore form contact surfaces on which the tool orthe tool parts come into contact with the layers, as well as welding surfaces via which the 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 designs, both tool parts can also introduce the required energy through differently heated or tempered sections of the forming surfaces. In still further designs, the temperature of the forming surface can be controlled differently in at least two sections via just one tool part. The other tool part cannot be operated on its forming surface or, for example, can only be actively operated in a first temperature or a second temperature range. E.g.a tempering of one section can be carried out analogously to the opposite first or second section of the forming surface of the other tool part.

[0017] The energy input can also be influenced by the thermal conductivity of the welding tool or the material of the tool parts. For example, a higher energy input may be necessary if the material of the tool part has better thermal conductivity in at least a second section than the material of the tool part in at least a first section, because the thermal energy "flows away" more quickly.

[0018] In further embodiments, the forming surface of at least one tool part can be electrically heated. The heating can be used to control the temperature of the at least one first section. In addition, the at least one second section can also be additionally temperature-controlled, e.g. heated, directly or indirectly. The temperature, in particular the surface temperature on the forming surface, of the at least one second section can then be influenced via the at least one temperature-control device. In further embodiments, the at least one temperature-control device can have at least one controllable heating device so that the surface temperature is adjustable. This allows adjustment if a change is required with regard to the material to be joined (plastic material, layer structure, etc.) and / or a correction is necessary because the joining result deviates from a predetermined tolerance range.For this purpose, an additional station or control device can be provided which checks the welded joints (e.g. circumferential welding, peel seam welding, port welding, etc.) (optically, mechanically, electrically, etc.).

[0019] 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.

[0020] In further embodiments, the at least one first section and the at least one second section can be separated from each other by at least one air gap and / or an insulator. This can further support the temperature control of the at least one first section and the at least one second section.

[0021] In further embodiments, the at least one air gap can be variable, for example to make an adjustment if there is a change in the bags to be produced (change in the product type), a deviation in the connection points produced in bags and / or reaching or exceeding or falling below temperature limit values ​​in at least one tool part or its forming surfaces.

[0022] In further embodiments, the at least one first section and the at least one second section of the at least one tool part can be completely separated from one another by the at least one air gap. The at least one tool part has at least two sections (first section, second section) or

[0023] Tool components that are not in direct thermal contact with one another. This significantly simplifies the adjustment of the different surface temperatures of the at least two sections. In further embodiments, the at least one temperature control device can be designed to bring a fluid to the second temperature range and to guide the fluid through at least one channel in the at least one second section. The fluid can thus be used to actively adjust or change the temperature, with the at least one welding device increasing or reducing the basic heating.

[0024] In further embodiments, the second temperature range and / or the fluid can be changed by the at least one temperature control device.

[0025] In further embodiments, the at least one first section can be arranged in the region of a circumferential connection for a medical bag and the at least one second section can be arranged in the region of a peel seam for a medical bag. In this case, the peel seam is to be designed to be weaker than the circumferential connection so that it can be opened if necessary without damaging the circumferential connection, which would lead to an unwanted escape of an agent contained in a bag. For this purpose, the peel seam is to be subjected to a lower temperature when the at least two layers are joined than the region with the circumferential connection. In this case, the temperature of the at least one second section for the peel seam can be cooled via the temperature device so that the surface temperature of the shaped surfaces of the second section is below the surface temperature of the at least one first section.

[0026] In further embodiments, the at least one first section or the at least one second section can be arranged in the region of a connector for a medical bag. Such a connector can be a so-called port, for example. A port can be used to fill a bag with a medication, a solution, or blood. A port can also be used to remove a medication, a solution, or blood from a bag. Different types of ports can be used for this purpose.

[0027] In further embodiments, the diameter, cross-section, and spacing of an air gap can vary depending on the first temperature range, the second temperature range, and / or the material to be joined in the medical bag being manufactured. In particular, an adjustment or modification of an air gap can be adjusted according to the aforementioned parameters.

[0028] The above-mentioned object is further achieved by a method for producing medical bags using a device according to one of the above embodiments with at least one welding device for forming at least one first connection on a medical bag and at least one temperature control device, wherein at least a first section of a tool part is brought to a first temperature range by the at least one welding device, and wherein at least a second section of the at least one tool part is brought to a second temperature range, wherein the first temperature range and the second temperature range differ from one another.

[0029] In further embodiments, the at least one second section can be cooled by the at least one tempering device in order, for example, to provide a connection between the layers of a bag which is designed to be weaker than other connections.

[0030] In further embodiments, the at least one temperature control device can temperature control a fluid which is passed through at least one channel in at least one second section.

[0031] In further embodiments, the volume flow can be varied for different areas of the at least one second section and / or for at least two second sections to achieve different cooling. This allows for further temperature adjustment, whereby it is sufficient to bring only one fluid to a single temperature. Adjustment and variation of the volume flow can be controlled, for example, via a switch, valve, or a conveying device.

[0032] Further features, embodiments and advantages emerge from the following presentation of embodiments with reference to the figures.

[0033] Brief description of the figures In the drawings shows:

[0034] Fig. 1 is a perspective view of a lower tool part of a welding tool;

[0035] Fig. 2 is a schematic representation of a bag blank produced with a welding tool according to the embodiment of Fig. 1;

[0036] Fig. 3 is a schematic representation of a lower tool part of a welding tool;

[0037] Fig. 4 schematic representations of further embodiments of tool parts of a welding tool; and

[0038] Fig. 5 schematic representations of further designs of welding tools; and

[0039] Fig. 6 is a schematic representation of a method for combined welding.

[0040] Detailed description of implementation examples

[0041] 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."

[0042] The drawings show various designs of a device for combined joining and components thereof, as well as a method for combined welding in a single welding station. Fig. 1 shows a perspective view of a lower tool part 110 of a welding tool 100, which can be used in 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 seam 312 and a peel seam 314 can be produced jointly and simultaneously in the welding tool 100. Fig. 1 shows one possible embodiment, which in further embodiments can have additional components or other configurations.

[0043] The welding tool 100 forms a device for producing medical bags that have at least two layers of a plastic material (e.g., EVA, PVC, PE, PP). The welding tool 100 comprises at least one welding device configured to form at least one first connection on a medical bag by temperature-regulating at least a first section 116 of at least one tool part 110 in a first temperature range, and at least one temperature-regulating device configured to bring at least a second section 124 of the at least one tool part 110 to a second temperature range that is different from the first temperature range. The welding device can be formed by a heating device 130, and the temperature-regulating device can be formed by a channel 144 through which a fluid is conducted that temperature-regulates (e.g., cools or heats) the surrounding area.

[0044] The layers can have several layers that consist of the same and / or different materials and can have different layer thicknesses from each other.

[0045] The exemplary embodiment of a lower tool part 110 shown in Fig. 1 has a tool body 112 made of a heat-conducting material, e.g., aluminum. In the exemplary embodiment shown, the tool body 112 has a rectangular basic shape that surrounds an inner space on the sides and bottom. A central web 120 is arranged in the space. The central web 120 can be made of the same material as the tool body 112. The tool body 112 and the central web 120 each have a high thermal conductivity. In further embodiments, the tool body 112 and the central web 120 can be made of different materials that have different thermal conductivities, so that heating or heat input and heat conduction in the central web 120 and the tool body 112 are different from one another.This ensures that no different tempering of the sections 116 and 124 assigned to the components tool body 112 and center web 120 is additionally supported and significantly influenced.

[0046] In the exemplary embodiment shown in Fig. 1, the tool body 112 has a circumferential first section 116 which forms a first welding surface 114 for a circumferential weld for a medical bag. The tool body 112 can be heated to an adjustable temperature via a heating device 130 (see Figs. 3-5). The surface temperature at the first welding surface 114 can thus be adjusted via the heating device. The first section 116 protrudes 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 produced only in the region of first sections 116 or first welding surfaces, wherein the material for the medical bag comes into contact with the tool body 112 only in the region of the first welding surfaces 116 to produce a circumferential weld seam 312.

[0047] The central web 120 is arranged in the tool body 112 such that the central web 120 has at least one first air gap 118 on each of its end faces opposite the tool body 112. The central web 120 is thermally separated from the tool body 112 via the two first air gaps 118 shown. In further embodiments, thermal insulators can be incorporated into the air gaps 118. The central web 120 forms a second section 124 of the tool part 110. On its upper side, the central web 120 has a second welding surface 122.

[0048] The central web 120 can, as shown in Fig. 4 a) to c), be in contact with the tool body 112 on its underside or have a second air gap 119. Instead of a second air gap 119, thermal insulators can be arranged, which significantly influence the transfer of thermal energy from the tool body 112 into the central web 120. For example, thermal insulators can be used to reduce the amount of thermal energy introduced into the central web 120, so that a different surface temperature on the welding surfaces 114, 122 can be significantly influenced. In further embodiments, the central web 120 can be connected to the tool body 112 via at least one connecting element. Such a connecting element can, for example,a raised portion on the tool body 112 on which the central web 120 rests, a strip or the like on the underside of the central web 120 that rests on the tool body 120, and / or a screw with which the central web 120 is connected to the tool body 112. Several, even different, connecting elements can be provided for a connection between the tool body 112 and the central web 120. In further embodiments, such connecting elements can be provided for a connection between a tool body and an insert made of a heat-conducting material, wherein the insert is designed to form a further seam and / or to connect layers of a film composite with a connecting element (port, tube, etc.) and is connected to the tool body at a corresponding location.

[0049] In the exemplary embodiment shown, the tool body 112 has a connection 140 which is connected to a feed 142. A fluid is supplied via the feed and is guided through the central web 120, insulated from the tool body 112. For this purpose, the tool body 112 can have insulation which thermally insulates a line or a channel section from the surrounding tool body 112. The central web 120 has a channel 144 which runs through the central web 120 and is thermally connected to the central web 120. The temperature of the fluid which is guided through the channel 144 thus influences and actively regulates the temperature of the central web 120 and thus of the second section 124 as well as the surface temperature of the second welding surface 122. For example, the central web 120 can be cooled using a fluid. Furthermore, for example.The surface temperature of the second welding surface 122 can be brought to a lower temperature level despite heating via the heating device 130 due to the thermal contact with the tool body 112 (see, for example, the embodiments of Fig. 4 b), c) and Fig. 5 a), b). In particular, the surface temperature of the second welding surface 122 can be actively controlled.

[0050] Since basic heating of the central web 120 is required in the illustrated embodiments, the aforementioned embodiments have only a first air gap 118 between the central web 120 and the tool body 112. The combination of the air gap 118 and the active temperature control of the second section 124 ensures that the welding surfaces 114, 122 do not deviate from a target temperature. This prevents a compromise in surface temperature, especially in the adjacent areas.

[0051] In the illustrated embodiments, the welding surfaces 114, 122 lie in one plane. In further embodiments, for example, the second welding surface 122 can be arranged slightly offset from a first welding surface 114, so that with a closed welding tool 100, there is less contact between the film and the second welding surface 122 and thus a lower temperature effect in this area. This can further influence the heat input.

[0052] Fig. 2 shows a schematic representation of a bag blank 310 produced with a welding tool 100 according to one of the embodiments of Fig. 1, 3, 4, or 5. In the exemplary embodiment, the bag blank 310 is produced from a film composite 300 consisting of two layers of a plastic film or a plastic film layer. In alternative embodiments, the two layers can also be formed by folding a plastic film or a layer system.

[0053] The two layers are welded circumferentially in the region of a circumferential weld seam 312. For this purpose, a welding temperature within a first temperature range (e.g., 105 to 160°C, in particular 130-150°C, preferably approximately 140°C) has been introduced into the region of the circumferential weld seam 312. A peel seam 314 runs in the center, which was produced at a welding temperature that is lower than the welding temperature of the circumferential weld seam 312 and, for example, lies in a temperature range of 105 to 130°C, preferably approximately 120°C. As a result, the connection between the two layers in the area of ​​the peel seam 314 is weaker than in the area of ​​the circumferential weld seam 312, so that when pressure is applied to a bag made from the bag blank 310, the peel seam 314 breaks before the circumferential weld seam 312 is damaged.

[0054] In further embodiments, a circumferential weld seam 312 can be interrupted, with ports for introducing or discharging liquids (e.g. medication, blood, etc.) being welded into the interrupted areas. The connection of the ports to the layers of a bag can also take place in a different temperature range than the welding temperature of the circumferential weld seam 312. The formation of the peel seam 314 requires a homogeneous welded connection, whereby the temperature gradient, i.e. deviations from a predetermined welding temperature for the peel seam 314, must be zero. The reason for this is that the connection of the peel seam 314 must be so strong when used as a medication bag that at least two liquids separated by the peel seam 314 cannot mix. Mixing may only take place after the connection of the peel seam 314 has been broken. This requires that a defined force be applied.If, however, the welding temperature for a peel seam 314 has a relatively large temperature range, the peel seam 314 also has connection areas of varying strengths over the entire length of the peel seam 314. A relatively large temperature range can result if no demarcation, as achieved with the design of the welding tool 100 presented here, is achieved between a peel seam 314 and a circumferential weld seam 312 for the edge of a medical bag.

[0055] The bag blank 310 shown in Fig. 2 has two transitions 316 between the peel seam 314 and the peripheral weld seam 312. Due to the design of the welding tool 100 with the air gaps 118 and the separation of the tool components (tool body 112 and center web 120), as well as the different temperature control, the transitions 316 are minimal and can be, for example, smaller than 1 mm, preferably approximately 0.5 mm. In contrast, transition regions from the prior art extend over a range of several millimeters to centimeters.

[0056] As shown schematically in Fig. 1, the air gap 118 extends somewhat further on one side into the area of ​​the first welding surface 114. Such a design can, for example, allow the use of two similarly designed tool halves, so that when these tool halves are closed, 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, depending on the design and dimensions as well as the materials used (welding tool 100 and film material), be less than 1 mm, preferably approximately 0.5 mm. The designs shown make it possible to keep transitions 316 between a circumferential weld seam 312 and a peel seam 314 to a minimum, whereby the welding surfaces 114, 122 can be brought exactly to the required temperature and thus do not have to provide a compromise. An offset of opposing air gaps 118 can also be used in the designs of Fig.4, so that, unlike shown, the air gaps 118 of the two opposite tool parts 110, 180 do not lie directly on top of each other.

[0057] A key feature of the solution presented here is that the peel seam 314 itself forms a homogeneous connection between the layers, which exhibits no deviation in strength over its entire length or extension. The separation of sections 116 and 124 of a welding tool 100 via the air gaps 118 thus ensures that the welding temperature in the area of ​​the peel seam 314 is kept essentially constant.

[0058] Fig. 3 shows a schematic representation of a lower tool part 110 of a welding tool 100. Fig. 3 shows a schematic representation of the welding areas in the sections 116, 124 of a welding tool 100, as shown schematically in Fig. 1, for example.

[0059] The tool body 112 is heated via a heating device 130. The heating device 130 can be designed as a resistance heater. Heating elements of the heating device 130 can be located in the region of a lower, closed surface of the tool body 112, so that basic, flat heating of the tool body 112 can be provided from below. Fig. 3 shows a heating zone 132 for the illustrated tool part 112. In the exemplary embodiment shown, the tool body 112 is heated in the heating zone 132; due to the design of the tool body 112 and the material properties, the entire tool body 112 can be heated via this zone. For example, the tool body 112 can be heated to a temperature in the range of 105 to 160°C, in particular 130-150°C, preferably approximately 140°C. Thus, after a heating phase in the first section 116, a corresponding welding temperature prevails at the welding surface 114.

[0060] A channel 144 runs through the central web 120, through which a fluid can be conducted, bringing the central web 120 to a temperature different from the temperature in the tool body 112. For example, the central web 120 can be cooled by a fluid so that the second section 124, and thus the welding surface 122, have a low surface temperature for welding. The basic heating of the central web 120 for the required minimum welding temperature can also be provided by the heating device 130, for which purpose the central web 120 can be in thermal contact with the tool body 112 in certain areas.

[0061] The connection 140 for the supply 142 and another connection on the opposite side of the tool body 112 have the shortest connection to the channel 44 in the central web 120, so that thermal contact is minimized. Additional insulation may be provided in the tool body 112. The arrangement of the channel 144 and the connections 140 with the supply 142 and a discharge on the opposite side enables a change or control of the temperature in the central web 120 and in particular at the second welding surface 122.

[0062] Figs. 4a) to c) show schematic representations of further embodiments of tool parts 110 of a welding tool 100. In the embodiments of Fig. 4, a flat heating device 130 is arranged in the lower base region of the tool body 112. The heating device 130 in the heating zone 132 is connected to a power supply and control system via at least one connecting line 134 in order to provide the required heating of the tool body 112.

[0063] Fig. 4a) shows a tool part 110 that has a substantially rectilinear channel 144 and a supply and discharge channel. A fluid for controlling the temperature of the central web 120 can thus be passed through the central web 120 as quickly as possible and has a reduced contact distance through the tool part 110.

[0064] The cross-section (diameter and cross-sectional shape) and course of the channel 144 can be designed differently than shown in the figures. For example, the supply and removal of fluid can take place from one side only, wherein the fluid is deflected at least once in the central web 120, i.e. the direction of flow in the central web 120 is reversed at least once with respect to the extent of the central web 120. The course of the channel 144 can also be, for example, sinusoidal, rectangular, wave-shaped, sawtooth-shaped or triangular. The distances between individual sections, like the sections themselves, can be of different lengths with respect to the extent of the central web 120 and have different heights from one another. In further embodiments, the cross-section of the at least one channel 144 in the central web 120 is designed such that the largest possible volume flow of fluid can be conducted through the channel 144. This can therefore be used, for example, toCooling of the central web 120 can be achieved within a very short time, even at a relatively high temperature in the central web 120, which, for example, is as high as the temperature in the tool body 112. This effect can also be significantly influenced by, or depend on, the flow velocity and temperature of the fluid. Therefore, in further embodiments, cooling of a central web 120 via a fluid does not require consideration of (long) start-up or cooling times, which, for example, last at least several minutes.

[0065] In Fig. 4a), the central web 120, in addition to the air gaps 118 on its end faces, has an air gap 119 to the tool body 112 on the bottom surface. The air gap 119 can be ensured via a line connected to the channel 144 and the tool body 112, thus holding the central web 120 in position. In further embodiments, the air gap 119 can be formed by an insulator. In such embodiments, the central web 120 can be brought to the required temperature solely by a fluid that is passed through the channel 144.

[0066] Fig. 4b) shows a design in which the central web 120 is in direct contact with the tool body 112 on its underside and is thus heated from below. A fluid passed through the channel 144 can reduce the surface temperature at the welding surfaces 122 in the second section 124.

[0067] Fig. 4c) shows a further embodiment in which the channel 144 in the central web 120 is directed upwards, so that the tempering or cooling takes place in the immediate vicinity of the second welding surface 122, whereby the welding temperature can thus be adjusted more precisely because the influence of "afterflowing" heat from below from the tool body 112 is reduced.

[0068] Fig. 5a) and b) show schematic representations of further embodiments of welding tools 100, wherein an upper tool body 180 of a welding tool 100 is shown. When welding medical bags, a film composite 300 is introduced between a lower tool part 110 and the upper tool body 180 and is then welded by closing the welding tool 100 in the region of a circumferential weld seam 312 at a first temperature and simultaneously in the region of a peel seam 314 at a second temperature, wherein the film composite 300 only comes into contact with the first sections 116 and the second sections 124 of the opposite tool parts in the region of the points to be welded.

[0069] In the embodiment of Fig. 5a), the tool body 180 is configured essentially identically to the lower tool part 110 and, for this purpose, has first and second sections 116, 124 and heating device 130, as well as a channel 144 in a central web 120. Thus, the welded joint in a film composite 300 can be controlled from both sides by actively controlling the temperature of the respective sections 116, 124.

[0070] Fig. 5b) shows an embodiment in which the upper tool body 180 has a heating device 130 for basic heating in the area of ​​the first section 116, but no active temperature control in the second section. In further embodiments, the central web 120 in the upper tool body 180 can have an air gap 119 (see Fig. 4a), so that the thermal influence of the tool body 180 on the central web 120 is reduced.

[0071] Fig. 6 shows a schematic representation of a method 200 for combined welding.

[0072] In a first step, the welding tool 100, and in particular the tool body 112, for example, a lower tool part 110, an upper tool body 180, or both tool components, is tempered 210. At least a first section 116 is brought to a first surface temperature (for example, by heating), and a second section 124 is brought to a second surface temperature by active tempering (for example, cooling).

[0073] In a subsequent step, the welding tool 100 is opened 220 by relative displacement of the two tool components. In further embodiments, the welding tool 100 can also be opened 220 before a tempering 210 in order to reduce the thermal influence of the two tool components on one another. This may be necessary in particular if the sections 116, 124 that are in contact or opposite each other in the closed state of a welding tool 100 are heated or tempered differently in an upper tool body 180 and a lower tool part 110 with tool body 112 and center web 120 (see, for example, Fig. 5b).

[0074] After tempering 210 and opening 220, a film composite 300 can be inserted 230 between the two tool components during operation of the welding tool 100. The film composite 300 comprises at least two layers of a film material, which in further embodiments can have a layer structure made of several plastics. Alternatively, a film composite 300 can also be provided by folding over a layer of a film material. The film composite 300 can be fed endlessly or as a sheet into a welding station with a welding tool 100. In further embodiments, a film composite 300 can be preheated at least in certain regions before insertion 230.

[0075] After the film composite 300 has assumed a defined position between the tool components, the welding tool 100 is closed 240 by relative displacement of the two tool components.

[0076] When the welding tool 100 is closed, a simultaneous welding 250 of regions of the film composite 300 with different temperatures takes place. In this case, the film composite 300 is welded in the region of the first sections 116 at a first welding temperature and in the region of the second sections 124 at a second welding temperature, wherein the first welding temperature and the second welding temperature are different from one another. In still further embodiments, a welding tool 100 can have at least one further section (third section, fourth section, fifth section, etc.), wherein the at least one third section and further sections have a different surface temperature than the first section 116 and the second section 124 and from one another in order to provide a correspondingly adapted welded connection in a film composite 300.

[0077] Due to the heating of the first section 116 and the active temperature control of the second section 124, the welded joints created in the film composite 300 after welding and in a bag blank 310 are formed differently. After welding 250, the welding tool 100 is opened 260 and then removed or ejected 270 by the welded film composite 300 with at least one bag blank 310 or, in further embodiments, a bag blank 310. Thus, in further embodiments, a film composite 300 can already be prefabricated to the external dimensions. In still further embodiments, a welding tool 100 can have additional cutting devices so that a bag blank 310 can be completely or partially separated from a film composite 300 after welding.

[0078] After joining, the previously welded areas can be cooled in another tool.

[0079] By precisely separating sections 116, 124 across at least one air gap 118, as well as separately cooling or heating at least a second section 124 of the tool parts or at least one tool part, for example, a peripheral weld for the layers of a medical bag to be joined and the formation of a peel seam 314 can be performed in a device or station, or a tool. In particular, the welding temperature can be individually adjusted to the respective requirement (port welding, peripheral welding, peel seam welding) without compromise.

[0080] The basic heating of the welding tool 100 can be achieved, for example, with a controlled electrical resistance heater. This allows the peripheral welding to be carried out at a first temperature within a first temperature range, which depends, for example, on the materials used for the layers. The layers typically each have a layer structure made of different plastic films and / or film thicknesses.

[0081] Various connections (ports, valves, etc.) can be inserted between the layers. The two layers are usually formed by folding a single layer or two layers that are brought into contact with each other so that they are congruent. In the area for at least one connection (port, valve, etc.), the layers can be opened or left open. At least one connection (port, valve, etc.) is then inserted between the layers in this area. This can be done, for example, before insertion into a station or facility for connection, or in the station or facility.

[0082] During the connection, two tool parts are then moved towards each other, whereby a circumferential welding of the two layers takes place in the area of ​​the forming surfaces or welding surfaces 114. For this purpose, in one embodiment, the forming surfaces are brought to the required first temperature (e.g. 150°C for PP) via a controllable electrical resistance heater, whereby the required temperatures for welding depend on the material to be joined. At the same time, the connection of the at least one connection (port) between the two layers can take place, whereby this area can be a second section which, compared to the first section 116, can be brought to a second temperature within a second temperature range via the temperature control device, whereby the first and second temperature (range) are different from one another. Thus, both the first section 116 and the second section 124 can be specifically heated 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 (port, valve, etc.) between the layers, whereby the temperature for the connection of at least one connection / port is higher than the temperature for joining the layers or at least one layer of the layers. The higher welding temperature is also required, for example, because holders for connection tubes can dissipate heat. For example, a connection may be required at at least two different temperatures, whereby 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 therefore cannot be used for the actual welding.

[0083] Depending on the application, the temperature control device can act on the required area in order to achieve the required temperature, for example by cooling or heating.

[0084] As shown in the figures, a central section (second section 124) of a welding tool 100 (welding tool lower part (110) and / or upper part (180)) can be cooled by a fluid flowing through the second section 124, so that a lower temperature is present in this area than in the remaining, first section 116 of the welding tool 100, in which circumferential welding is carried out to connect the two layers.

[0085] In various designs, for example, a combination of circumferential welding and port welding, circumferential welding and peel seam welding, and others are possible. The exact separation of the temperatures is achieved by the technical teaching described herein, which delivers a good result especially when combined with a peel seam 314, since no temperature gradients are permitted with a peel seam 314. This can be easily achieved by a mechanical separation of the tool areas or sections 116, 124 (air gap 118 / insulator) and, for example, liquid temperature control of a tool area (e.g. second section 124). The basic heating of the welding tool 100 can be provided with a regulated electrical resistance heater. Thus, a simple tool design and a simple, combined joining method are provided, particularly for peel and circumferential welding, so that, for example,Both circumferential welding and peel seam welding can be carried out in one station and in one process step.

[0086] The temperature control device can be time-controlled via a controller. Furthermore, the temperature, flow rate and flow direction (also varying) can be regulated via a controller and / or the temperature control device in order to bring the at least one second section 124 to the required second temperature and to maintain it. In still further embodiments, several sections can be provided which are brought to different temperatures compared to a heating of a first section 116 via at least one welding device, wherein the sections can be thermally separated from one another via air gaps or other insulators. In still further embodiments, by the formation of channels 144 (length per section, diameter) and optionally by a time control (e.g.via valves) with only one fluid that is brought to a second temperature, different temperatures can be set and maintained in the different sections.

[0087] In still further embodiments, the described technique can also be used to combine other joints instead of a circumferential, port and peel seam 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 or to take heat conduction through tool components into account.

[0088] List of reference symbols

[0089] 100 welding tools

[0090] 110 lower tool part

[0091] 112 tool body

[0092] 114 first welding surface

[0093] 116 first section

[0094] 118 first air gap

[0095] 119 second air gap

[0096] 120 central bridge

[0097] 122 second welding surface

[0098] 124 second section

[0099] 130 Heating device

[0100] 132 heating zones

[0101] 134 connecting cable

[0102] 140 connection

[0103] 142 Feed

[0104] 144 Channel (continuous line for one fluid)

[0105] 180 upper tool body

[0106] 200 procedures

[0107] 210-270 process steps

[0108] 300 film composite (2 layers of plastic material)

[0109] 310 bags of raw ling

[0110] 312 circumferential weld (edge)

[0111] 314 peel seam

[0112] 316 Transition (between peel seam and circumferential weld seam)

Claims

Patent claims 1. Device for producing medical bags which have at least two layers of a plastic material, with at least one welding device which is designed to form at least a first connection on a medical bag by tempering at least a first section of at least one tool part in a first temperature range, and at least one tempering device which is designed to bring at least a second section of the at least one tool part to a second temperature range which is different from the first temperature range.

2. Device according to claim 1, comprising 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 in the at least one first section, 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 claims 1 to 3, wherein the at least one temperature control device has at least one controllable heating device.

5. Device according to claim 4, wherein the heating device comprises an electrical resistance heating device.

6. Device according to one of claims 1 to 5, wherein the at least one first section and the at least one second section are separated from one another by at least one air gap and / or an insulator.

7. Device according to claim 6, wherein the at least one air gap is variable.

8. Device according to claim 6 or 7, wherein the at least one first section and the at least one second section of the at least one tool part are completely separated from one another by the at least one air gap.

9. Device according to one of claims 1 to 7, wherein the at least one temperature control device is designed to bring a fluid to the second temperature range and to guide the fluid through at least one channel in the at least one second section.

10. Device according to one of claims 1 to 9, wherein the second temperature range and / or the fluid can be changed by the at least one temperature control device.

11. Device according to one of claims 1 to 10, wherein the at least one first section is arranged in the region of a circumferential connection for a medical bag and the at least one second section is arranged in the region of a peel seam for a medical bag.

12. Device according to one of claims 1 to 11, wherein the at least one first section or the at least one second section is arranged in the region of a connector for a medical bag.

13. Device according to one of claims 6 to 12, wherein the diameter, cross-section and distance of an air gap varies according to the first temperature range, the second temperature range and / or the material to be joined of the medical bag to be produced.

14. A method for producing medical bags using a device according to one of claims 1 to 13 with at least one welding device for forming at least one first connection on a medical bag and at least one temperature control device, wherein at least one first section of a tool part is brought to a first temperature range by the at least one welding device, and wherein at least a second section of the at least one tool part is brought to a second temperature range, wherein the first temperature range and the second temperature range differ from each other.

15. The method according to claim 14, wherein the at least one second section is cooled by the at least one tempering device.

16. The method according to claim 15, wherein the at least one temperature control device temperatures a fluid which is passed through at least one channel in the at least one second section.

17. The method according to claim 16, wherein the volume flow is changed for different regions of the at least one second section and / or for at least two second sections in order to achieve different cooling.

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