Method for connecting connection regions made of silicone

Abstract

The invention relates to a method for connecting a first connection region (6a) to a second connection region (6b). The connection regions (6a, 6b) consist of silicone. In order to establish a connection between the connection regions (6a, 6b), VUV beams (7) are applied to the regions. At the same time or subsequently, the connection regions (6a, 6b) are pressed against one another. The method according to the invention can be used as follows: for connecting the end faces of two silicone tubes; for connecting an inner surface of a silicone tube to a lateral surface of a connecting piece made of silicone; or for producing a sealed-off closure point of a silicone tube, which can then be severed in order to provide two sealed-off closed silicone tube parts.

Description

[0001] Method for joining silicone joints

[0002] TECHNICAL FIELD OF THE INVENTION

[0003] The invention relates to a method for connecting a first connecting region of a first object to a second connecting region of a second object or of the first object, wherein the connecting regions consist of silicone.

[0004] Silicone joints are used, for example, in objects, particularly products, in medical technology or in the construction, automotive, electrical or electronics industries.

[0005] "Silicone" refers to poly(organo)siloxanes, a group of synthetic polymers in which silicon atoms are linked via oxygen atoms. Silicones can have molecular chains or networks. It is possible that the remaining free valence electrons of the silicon are saturated by hydrocarbon radicals (especially methyl groups). Silicones therefore belong to the group of organosilicon compounds. Silicones can consist of individual siloxane units in which the silicon atoms that do not reach their octet by forming bonds with oxygen are saturated with organic radicals. Silicones include cyclic polysiloxanes, linear polysiloxanes, branched polysiloxanes, and crosslinked polysiloxanes. Silicones can have various substituents bonded to the silicon.The siloxane framework can contain various hydrocarbons, whereby silicon-functional and organofunctional groups can be present.

[0006] For example, the silicone in question here can be silicone rubber or a silicone elastomer. Silicone rubbers contain, for example, poly(organo)siloxanes, which contain additional groups for crosslinking reactions. These groups can be hydrogen atoms, hydroxyl groups, and vinyl groups, which can be located at the chain ends or incorporated into the chain. The silicone rubbers can contain reinforcing materials and fillers, the type and quantity of which influence the mechanical and chemical behavior of the silicone elastomers created by crosslinking. The silicone rubbers can be cold-cured ("RTV silicone rubbers") or hot-cured ("HTV silicone rubbers").Another crosslinking mechanism for silicone rubbers can involve the addition of Si-H groups to silicon-bonded vinyl groups, catalyzed, for example, by precious metal compounds. These groups can be incorporated into the polymer chains or at their terminals. One- and two-component systems can be used for RTV silicone rubbers.

[0007] Furthermore, the silicone can be in the form of a silicone resin, which can be cross-linked polymethylsiloxanes or polymethylphenylsiloxanes. Silicone resins can also be combined with organic resins, such as alkyd, epoxy, melamine, phenolic, and polyester resins. Copolymers of low-molecular-weight, hydroxy-functional silicones with polyesters, alkyd resins, and acrylic resins are also referred to as silicone combination resins.

[0008] Other forms of silicones are fluorosilicones and highly transparent silicones.

[0009] STATE OF THE ART

[0010] The publication

[0011] T. Yamamoto: "Solid-state bonding of silicone elastomer to glass by vacuum oxygen plasma, atmospheric plasma, and vacuum ultraviolet light treatment" Surface and Interface; Analysis 45 (2013) 817-822 investigates the possibilities of bonding a silicone elastomer to glass, whereby in this case, a surface modification of the silicone elastomer was carried out in the bonding area using oxygen plasma, atmospheric pressure plasma, and VUV rays. The VUV rays were applied to the surface of the silicone elastomer in the bonding area in the atmosphere at a distance of 3 mm, with an exposure of 30 mW / cm 2at room temperature (25 °C). The silicone elastomers used were Sylpot 184 (Dow Corning Corp.), SIM 240, SIM 260, and X-32-3094-2 (Shin-Etsu Chemical Co., Ltd.). To measure the induced surface modification, contact angle measurements were carried out with a water droplet placed on the surface of the treated silicone elastomer, measurements of the changes in material behavior over time, and strength measurements of the bond created between the silicone elastomer and a glass plate. For the strength measurements, a mushroom-shaped test specimen made of the silicone elastomer was used, the stem-side end face of which formed the bond area with the glass plate. After the surface treatment of this end face, the end face was brought into contact with the glass plate within two minutes.Before conducting the strength measurement, this contact was maintained for at least 24 hours to allow the bonding reaction to complete. For the strength measurements, the resulting bond was then subjected to a tensile force. The dependence of the bond strength on the treatment duration was investigated. It was found that the strength is highest when treatment with VUV rays lasts from a few seconds to approximately 100 seconds.

[0012] The website https: / / www.plastverarbeiter.de / verarbeitungsverfahren / silikone-ohne-klebstoff- fuegen.html

[0013] ("Joining silicones without adhesive"; date of access: August 1, 2022) proposes processes for the adhesive-free bonding of silicone materials to each other or to other materials such as aluminum, glass, or steel. A material-to-material bond between the bonding areas is to be achieved by irradiating the surfaces and subsequent joining, while maintaining the biocompatibility, temperature resistance, chemical resistance, and elastic properties of the silicone material. Application areas for silicone materials in medical technology include catheters, prostheses, breathing masks, ventilation masks, valves in ventilators, and all types of seals and hoses in medical devices. The website describes the problem that vulcanized silicones cannot be simply bonded.The reason given for this is that silicone elastomers have a chemically inert surface with a surface energy comparable to that of Teflon (PTFE). This low surface energy is unfavorable for adhesive wetting. The lack of polar groups further limits the necessary formation of reactive interactions between the adhesive and the substrate. The website describes that, for these reasons, adhesion promoters that are physiologically and environmentally unsafe are used to ensure sufficient adhesion for silicones. According to this website, basic compounds such as aliphatic amines, pyridine, and imidazole derivatives are used to create a strong bond with a non-polar silicone rubber surface. The website suggests creating polar functional groups that improve the adhesive properties by activating the bonding areas.Reference is made to a research project (IGF Project No.: 17551 N) in which it was demonstrated that silicone could be bonded without chemical adhesion promoters thanks to an activating pretreatment. In contrast, the website proposes bonding silicones entirely without adhesive. For this purpose, a bonding area is irradiated with VUV rays. A Xe excimer lamp emitting radiation with a wavelength of 172 nm is used as the radiation source. The radiation is intended to create bond breaks in the bonding area. A subsequent reaction with oxygen is then intended to make the bonding area reactive. With suitable contact, the bonding can then occur through the formation of chemical bonds. Corresponding research was conducted by Fraunhofer IFAM under the project name "Light-Modified Silicone Materials for Medicine and Technology."The project used Elastosil LR3004 / 40 silicone from Wacker, Burghausen, in the form of a 2 mm thick sheet material. This platinum-catalyzed, cross-linked silicone with an average hardness of 40 Shore A was used. Clad aluminum 2024, steel test specimens made from cold-rolled DC01 strip with a smooth, crack- and pore-free surface, and glass test specimens made from Borofloat from Rocholl, Eschelbronn, were used as the inorganic joining partner. After VUV irradiation of the bonding areas of the silicone sheet and the inorganic joining partner, they were brought into contact with each other and subjected to pressure for a specified time and heating with a heating press at an elevated temperature. Subsequently, the strength of the resulting bond was examined using a peel test based on DIN EN ISO 11339, and the roughness of the joining parts was examined using confocal microscopy.As part of the project, the power of the VUV rays was varied, with irradiation taking place under air and atmospheric pressure. It was shown that the strength of the resulting bond remained unchanged regardless of eight weeks of exposure to water and an elevated temperature of 180°C. The bonded areas were pressed together at temperatures between 100°C and 200°C, with pressures between 0.2 and 1.8 MPa being applied and the pressing time between 5 and 15 minutes. Because the bond was created using a hot press, the process used in the project is not suitable for joining three-dimensional objects. According to this website, the joining of three-dimensional objects should be the subject of future research.

[0014] The website https: / / www.ifam.fraunhofer.de / de / technologien / vuv-strahlung-optimiert- silikoneigenschaften-an-der-oberflaeche.html

[0015] ("VUV radiation optimizes silicone surface properties"; date of access: August 1, 2022) describes that silicones that can be used in medical or food technology are susceptible to wear and attract dirt, and have limited bonding properties. A high coefficient of friction in a silicone elastomer, which is responsible for its high susceptibility to wear and complicates the assembly of silicone O-rings, for example, can be reduced by up to 90% by irradiating the surface with UV rays, without impairing the otherwise positive mechanical properties of the silicones. Furthermore, irradiating the surface with short-wave UV radiation smoothes and hardens the surface, which in turn reduces the adhesion of dust and dirt particles.The website also mentions the activation of silicone bonding areas using UV radiation, allowing bonding with epoxy resins, polyurethane adhesives, or adhesive tapes, thus eliminating the need for chemical bonding agents. Alternatively, the website suggests bonding VUV-activated silicone surfaces without adhesives. Such a bond is proposed using the so-called bonding process for silicone joints in homogeneous or heterogeneous composites with glass, aluminum, or steel. The resulting bonds are said to be resistant to aging and hydrolysis. Reference is made to the IGF projects 17551 N, 18704 N, and 19773 N, which concern the modification of silicone using UV light.

[0016] The website https: / / www.sartorius.com / en / products / fluid-management / aseptic-disconnectors / biosealer-tube-sealer ("Biosealer® TC Aseptic Tube Sealing Device"; date of access: August 1, 2022) deals with sterile fluidic separations of thermoplastic tubing in biopharmaceutical manufacturing processes. It proposes a handheld sealing device into which a fluid-filled tube is inserted. The tube is compressed between two jaws in such a way that the fluid in the tube is displaced between the jaws and the tube is flattened between the jaws so that the opposing inner surfaces of the tube come into contact with each other. The application of heat then welds the flattened portions of the tube together. After cooling, the tube can be severed in the flattened portion.In this way, a fluidically tight and sterile end closure of the two tube pieces resulting from the severance can be created.

[0017] The publication US 2018 / 0161554 A1 relates to a connection between an outer synthetic resin tube and an inner synthetic resin tube extending through it. The synthetic resin tubes can also contain silicone resin or fluorine-containing silicone resin. The interconnected tubes are used to manufacture a balloon catheter for medical applications. US 2018 / 0161554 A1 describes a problem with such connections of synthetic resin tubes as being that a connection is only possible if the synthetic resin materials of the two tubes match. Using an adhesive for the connection can lead to undesired curing of the synthetic resin materials, thereby reducing the flexibility of the assembly consisting of the two tubes. US 2018 / 0161554 A1 proposes surface activation of the synthetic resin tubes by irradiating a surface with UV rays.Plasma treatment of the bonding area is also proposed. Before surface activation, the end regions of the outer resin tube are folded into a bead. In this state, the assembly, which consists of the inner resin tube and the outer resin tube with the folded beads, is rotated, and the beads are then irradiated with UV rays. The UV rays are generated by a radiation source and have a wavelength of 200 nm or less. An excimer radiation source with a wavelength of 172 nm, a low-pressure mercury radiation source with a wavelength of 185 nm, or a deuterium radiation source with a wavelength in the range of 120 nm to 200 nm can be used, with the power being 10 to 20 mV / cm. 2can be found. After irradiation, the plasma treatment takes place. The folded end regions of the outer synthetic resin tube are then folded back again so that the outer synthetic resin tube returns to its original hollow cylindrical shape. As a result, the folded back, activated outer surfaces of the bead come into contact with the outer surface of the inner synthetic resin tube, whereby a contact force in the range of 0.1 to 1.0 MPa can be generated. In addition, the connecting regions can be heated, with temperatures in the range of 100°C to 200°C being possible. Alternatively, US 2018 / 0161554 A1 proposes that the connecting end regions of the outer synthetic resin tube are first conically widened, activated and then pressed against the outer surface of the inner synthetic resin tube under radial compression.A radial expansion of the inner resin tube is also possible to achieve pressure on the connecting areas. It is also proposed to activate the surfaces for the connection using an electrode in an electrical conduction chamber containing a gas that enables an electrical discharge.

[0018] US 2013 / 0037207 A1 discloses a connection between a block-like housing and a cover. Fine fluidic channels are formed in the housing and closed by the cover. The microfluidic device thus formed is used for drug or pharmaceutical screening and DNA diagnostics. The housing and cover are made of silicone resin. The surface of the housing, to which the cover is to be applied, is activated with VUV radiation having an energy of 200 mJ / cm 2 up to 1500 mJ / cm 2and a wavelength of 172 nm. The cover is then pressed under pressure against the activated surface of the housing, which is intended to create siloxane bonds. In addition, the surface of the housing can be activated by an atmospheric plasma. The surface of the housing can also have protrusions with a height of several nanometers to several hundred nanometers, which can be used as electrodes for measurements. The housing can be made of a material that is transparent to VUV rays. The cover consists of a substrate onto which silicone resin is dripped to form a bonding layer with which the cover can be pressed onto the housing. This layer has a maximum layer thickness of 10 pm. At this point, the synthetic resin layer should not yet have any adhesive effect.To provide a form of lubrication between the housing and the cover, methanol can also be applied to the contact surface of the synthetic resin layer. Subsequently, the connection area is exposed to VUV rays through the transparent housing. The formation of an oxide film in the contact area bonds the cover to the housing.

[0019] EP 3 488 998 A1 discloses the production of a microchip for a microreactor for biochemistry. The microchip has a substrate with fine channels and can be made of silicone or silicone resin. The microchip consists of two interconnected substrates, which are plate-shaped with a size of, for example, 85 mm x 128 mm and a thickness of 1 mm to 3 mm. In an activation step, the surfaces of the substrates are exposed to VUV rays and an atmospheric plasma. VUV rays with a wavelength of a maximum of 200 nm, preferably 172 nm, are used, with the radiation in the range of 10 to 100 mV / cm 2and the substrates can be exposed to VUV rays for a period of 10 to 60 seconds. The substrates are then stacked on top of each other in such a way that the activated surfaces come into contact with one another. As a result of unevenness, for example wavy in the longitudinal section, gaps arise between the substrates. The substrates are pressed together with a contact force in the range of 0.1 MPa to 5 MPa, for example for 60 to 300 seconds. To eliminate the gaps, the substrates are also heated, which leads to the adaptation of the surfaces and thus to full-surface contact. The substrates can be bonded to one another by triggered chemical reaction processes, in particular a hydrogen bond between OH groups of the substrates or covalent bonds as a result of dehydration condensation.

[0020] OBJECT OF THE INVENTION

[0021] The invention is based on the object of proposing a new method for connecting connecting areas made of silicone, wherein the method is preferably used for connecting specific connecting areas of at least one object.

[0022] SOLUTION

[0023] The object of the invention is achieved by the features of the independent patent claim. Further preferred embodiments of the invention can be found in the dependent patent claims. DESCRIPTION OF THE INVENTION

[0024] The invention proposes a method for connecting a first connecting region to a second connecting region. The two connecting regions can be associated with different objects or with the same object. The connecting regions are made of silicone.

[0025] According to the invention, it is proposed that the first and / or second connecting region be exposed to VUV rays. VUV rays refer to vacuum ultraviolet rays with a spectral range of electromagnetic radiation. The spectral range of the VUV rays is preferably in the range from 0.2 nm to 200 nm, or 10 nm to 200 nm, or in the range from 100 nm to 200 nm, with the wavelength lying in particular between the spectral ranges of visible light and X-rays. The VUV rays preferably have a photon energy of at least 5 eV, preferably in the range from 6 eV to 6000 eV, and / or the VUV rays are high-energy, ionizing rays.

[0026] Preferably, according to the invention, an adhesive-free connection is made and no bonding agent is used. Furthermore, the invention is based on the finding that when the connecting areas are connected using clamps or other mechanical connections such as bands, the material is crushed, which can lead to undesirable mechanical damage, for example, leaks or material failure. It is also possible within the scope of the invention to create a fluid-tight connection between the connecting areas.

[0027] Preferably, within the scope of the invention, the pressing of the connecting regions against one another is maintained for less than one hour (for example, 1 minute to 50 minutes or 5 minutes to 40 minutes), at least one hour, at least five hours, at least ten hours, at least 15 hours, or even at least 24 hours. It is possible for the method, and in particular the exposure to VUV rays and / or the pressing of the connecting regions against one another, to be carried out under standard conditions, which includes the possibility of carrying out the method at 20°C and 65% humidity. For example, the connection between the connecting regions can be created by cross-linking processes in the silicone.

[0028] The parameters of the method, in particular the distance of a VUV radiation source from a connection area, a power of the VUV radiation source, the wavelength of the VUV rays and the contact force or surface pressure of the pressing of the connection areas against each other can be selected specifically depending on the type of objects to be connected and / or the materials of the connection areas (in particular the chemical composition and / or the structure).

[0029] Within the scope of the invention, it is possible for the connecting areas to be pressed together after the first and / or second connecting areas have been exposed to VUV radiation. For this embodiment, the connecting areas are first prepared by exposure to VUV radiation, and then contact is established between the connecting areas, thus establishing the connection.

[0030] However, in another proposal of the invention, the joining areas are pressed together while being exposed to VUV rays. This can shorten the joining process. On the other hand, it may prove advantageous to treat the joining areas with VUV rays while they are being pressed together.

[0031] For one proposal of the method according to the invention, the first and / or second connection area is exposed to oxygen free. For example, it is possible for the exposure to oxygen to occur in a (technical) vacuum. However, it is also possible for the first and / or second connection area to be exposed to oxygen in a chamber filled with an inert fluid. The inert fluid can be nitrogen, for example.

[0032] According to the invention, in connection with the exposure of at least one connecting region to VUV rays and / or the pressing of the connecting regions against one another, an elastic and / or plastic deformation of at least one object in the at least one connecting region occurs. The deformation can occur before, during, or after the exposure to VUV rays and / or before, during, and / or after the pressing of the connecting regions against one another.

[0033] By means of the elastic and / or plastic deformation of at least one object in the connection region, different effects which do not limit the invention can be brought about: a) The elastic and / or plastic deformation can lead to a change in the geometry of the contact surface of the connection region.

[0034] It is possible that this change in geometry ensures an increased contact area.

[0035] It is also possible that the change in geometry involves a reduction in thickness. This change in thickness can lead to a joint whose extension across the contact surface of the joining areas is reduced. However, the reduction in thickness can also be used advantageously to ensure particularly effective penetration of the VUV rays, possibly through the material in the joining area in the thickness direction.

[0036] It is also possible that the elastic and / or plastic deformation can lead to a structural change in the material, which means that the adhesive effect of the bonding areas can be activated particularly effectively using VUV rays and / or the bond can be particularly well formed with the applied pressure. b) It is also possible that, in the case of elastic and / or plastic deformation, this deformation remains even after the bond has been established. For example, residual elastic deformation can lead to tension between the objects in the bonding areas, which can have a positive effect on the bond created.

[0037] To achieve the object underlying the invention, the elastic and / or plastic deformation is induced by means of a force introduction body. In this case, the force introduction body has a material region that is at least partially transparent or transparent to the VUV rays, or the entire force introduction body consists of a partially transparent or transparent material region. For example, such a force introduction body or material region can be made of quartz glass or magnesium fluoride. In this case, the force introduction body is arranged between the object with the connection region and the radiation source in such a way that the connection region is exposed to the VUV rays from a VUV radiation source through the material region of the force introduction body.For example, it is possible for the force introduction body to be designed as a plate, cuboid, or other pressure body that exerts a normal stress on the object forming the connection area. For example, a quartz glass plate can be used whose thickness is less than 3 mm, more than 7 mm, or in the range of 3 to 7 mm, preferably 4 to 6 mm. The force introduction body designed in this way enables the application of the force to the object for elastic and / or plastic deformation while simultaneously ensuring the transmission of the VUV rays to bring about the desired modification of the connection area.

[0038] In principle, the connecting regions can be formed by a single arbitrary object or by two arbitrary objects, wherein the one object or the two objects can then consist of silicone only in the connecting region or can consist entirely of silicone.

[0039] For one proposal of the invention, the method is applied to an object forming a connection region, which is a hollow body with an interior space that preferably has an opening to the outside. In this case, the connection region of this object can be exposed to radiation from the interior space, which can be the case alternatively or cumulatively to exposure to the object from the outside. It is therefore possible for the VUV radiation source to be mounted and oriented such that the VUV rays enter the interior space via the opening in the interior space and act on an inner surface delimiting the interior space, wherein this inner surface preferably forms the connection region. Alternatively, however, it is possible for the VUV rays to be transmitted from this inner surface outwards through the object to an external connection region.

[0040] For another application of the method according to the invention, a single silicone tube provides the first connection region and the second connection region, which are then provided by diametrically opposed inner surface regions, each of which extends approximately 180° in the circumferential direction and directly adjoins one another. Upon exposure of at least one of the connection regions to VUV radiation, an elastic and / or plastic deformation is then induced by means of a force introduction body such that the inner surface regions are flattened and brought into contact with one another. Furthermore, the force introduction body can also cause the inner surface regions to be pressed against one another and, under certain circumstances, also cause a further elastic and / or plastic deformation, in particular a change in thickness, resulting therefrom.In this case, the force introduction body has a material region that is at least partially transparent to the VUV rays, in particular made of quartz glass or magnesium fluoride. The connecting regions to be exposed to the VUV rays are exposed to the VUV rays from a VUV radiation source through the material region of the force introduction body. Such a method can even be carried out when the silicone tube is filled with a fluid. By connecting the opposing inner surface regions to one another, a fluid-tight seal of the silicone tube can be achieved in the region of the created connection.

[0041] Preferably, the silicone hose is then cut in the area of ​​the connection areas, creating two pieces of silicone hose that are sealed fluid-tight at the ends.

[0042] To further achieve the objective underlying the invention, the two connecting areas are not directly connected to one another after treatment with VUV rays. Rather, the connecting areas (particularly if they are formed by opposing inner surface areas of a silicone tube) form a gap. An adhesive, any desired bonding agent (e.g., in the form of a curing bonding fluid or pasty medium), or a bonding body can then be introduced into this gap, which then forms the bond with the bonding areas treated with VUV rays.

[0043] To design the object as a silicone hose, the silicone hose can first be elastically and / or plastically deformed using a force introduction body in such a way that the silicone hose flattens, in the area where the inner surface areas of the silicone hose come into contact with one another. In a subsequent process step, a separation point can then be created using a separating tool, which separates the silicone hose pieces from one another. Subsequently, a force introduction body part is moved away from the end areas of the silicone hose pieces. The intermediate spaces can then be formed in these end areas, which can be achieved in particular by the elastic recovery of the walls of the silicone hose pieces in the end areas or by additional measures.The inner surface areas are then exposed to VUV rays using a radiation source in the gaps adjacent to the separation point. An adhesive, bonding agent, or joining body can then be introduced into the gaps, which then forms a bond with the inner surface areas.

[0044] It is possible that the described methods are used to seal a product filled with a fluid, for example a container for a sterile product.

[0045] According to a further solution to the problem underlying the invention, a first object, which forms the first connection region, is a first silicone hose, while a second object, which forms the second connection region, is a second silicone hose. In this case, the connection regions are the respective end faces of the silicone hoses. Thus, for this embodiment of the invention, the end faces of the silicone hoses are first exposed to the VUV rays. The two end faces are then pressed against one another so that a fluid-tight silicone hose strand can be created from the two silicone hoses. For this purpose, the two silicone hoses preferably have the same inner and / or outer diameter or at least an overlapping diameter range.

[0046] For a further solution to the problem underlying the invention, a first object forming the first connection region is a silicone hose. In this case, the first connection region is an end-side inner surface of the silicone hose. A second object forming the second connection region has a fluidic connection piece. The fluidic connection piece has a silicone outer surface. The connection piece can be made entirely of silicone, or a silicone layer or sleeve can be applied to the connection piece, which then forms the outer surface. In this case, the outer surface forms the second connection region.After the first and / or second connection area has been exposed to VUV rays, the silicone tube is pulled over the connection piece, whereby the connection areas come into contact with each other and the adhesive connection and / or cross-linking takes place in the connection areas.

[0047] It is possible for the silicone hose to be pressed inward against the connecting piece using clamping jaws, a temporary clamp, or a pressure body. According to one proposal of the invention, the connecting piece has an oversize relative to the silicone hose, so that when the hose is pulled over, an elastic expansion of the silicone hose and / or radial compression of the connecting piece must occur, which then ensures the contact pressure between the connecting areas. The contact pressure can then be specified based on the extent of the oversize.

[0048] For this design, the inner surface of the silicone hose can be exposed to VUV rays through the interior of the silicone hose.

[0049] Within the scope of the invention, VUV rays of any wavelength or a superposition of different wavelengths can be used. For a particular proposal, the VUV rays have a wavelength of approximately 172 nm or 185 nm, although this also includes the possibility that the wavelength may deviate by ± 10%, ± 5%, or ± 2% from the aforementioned wavelengths.

[0050] Advantageous further developments of the invention emerge from the patent claims, the description and the drawings.

[0051] The advantages of features and combinations of several features mentioned in the description are merely exemplary and can be effective alternatively or cumulatively, without the advantages necessarily having to be achieved by embodiments according to the invention.

[0052] With regard to the disclosure content – ​​not the scope of protection – of the original application documents and the patent, the following applies: Further features can be found in the drawings – in particular the illustrated geometries and the relative dimensions of several objects to one another, as well as their relative arrangement and operative connection. The combination of features of different embodiments of the invention or features of different patent claims is also possible, deviating from the chosen references of the patent claims, and is hereby encouraged. This also applies to features that are illustrated in separate drawings or mentioned in their description. These features can also be combined with features of different patent claims.Likewise, features listed in the patent claims may be omitted for further embodiments of the invention, but this does not apply to the independent patent claims of the granted patent.

[0053] The number of features mentioned in the claims and the description is to be understood as meaning that exactly this number or a greater number than the stated number is present, without the need for the explicit use of the adverb "at least." Thus, for example, if reference is made to one element, this is to be understood as meaning that exactly one element, two elements, or more elements are present. The features mentioned in the claims may be supplemented by further features or may be the only features present in the subject matter of the respective claim.

[0054] The reference signs contained in the patent claims do not represent a limitation of the scope of the subject-matter protected by the patent claims. They serve solely to make the patent claims easier to understand.

[0055] BRIEF DESCRIPTION OF THE CHARACTERS

[0056] In the following, the invention is further explained and described with reference to preferred embodiments shown in the figures.

[0057] Fig. 1-3 show process steps of a method for connecting two objects, each of which is a silicone tube.

[0058] Fig. 4-6 show process steps of a method for connecting an object to a connecting piece with a silicone hose.

[0059] Figs. 7-10 show process steps of a method for producing two silicone hose pieces from a single silicone hose, which may be filled with a fluid, and which are sealed fluid-tight at a separation point. Figs. 11-15 show process steps of another method for producing two silicone hose pieces from a single silicone hose, which may be filled with a fluid, and which are sealed fluid-tight at a separation point.

[0060] FIGURE DESCRIPTION

[0061] In the following figures, the same reference symbol is used for some objects or features that are similar in terms of their design and / or function. These objects or features can then be distinguished from one another by an additional letter a, b. These objects or features can then be referred to without the use of the additional letter, meaning that the reference number can refer to one object or feature, several objects or features, or all objects or features.

[0062] Fig. 1 shows a first object 1 and a second object 2, each embodied as silicone tubes 3a, 3b. Fig. 1 merely schematically shows the end regions of the silicone tubes 3 to be connected. The silicone tubes 3 preferably have the same inner and outer diameters, and they can be made of the same or different silicone materials.

[0063] According to Fig. 1, the silicone tubes 3 are arranged in the area of ​​a VUV radiation source 4 such that a radiation area of ​​the radiation source 4 is aligned with end faces 5a, 5b of the silicone tubes 3a, 3b. The end faces 5a, 5b form connecting areas 6a, 6b, in which the silicone tubes 3a, 3b are to be fluid-tightly and permanently connected to one another to form a silicone tube strand.

[0064] In a subsequent process step, shown in Fig. 2, the radiation source 4 is activated. This results in the connecting regions 6a, 6b being exposed to VUV rays 7. For the illustrated embodiment, the two end faces 5a, 5b are exposed to the VUV rays 7 simultaneously from a common radiation source 4. It is also possible for one radiation source 4 to expose the connecting regions 6a, 6b one after the other with VUV rays 7, or for two radiation sources 4a, 4b to be present, each exposing an associated connecting region 6a, 6b to VUV rays 7. Once such treatment of the connecting areas 6a, 6b with VUV rays 7 has been carried out for a predetermined period of time, the connecting areas 6a, 6b are pressed against one another with a contact force 8 while the silicone tubes 3a, 3b are aligned coaxially, so that a flush inner and outer surface is obtained (Fig. 3).The contact force 8 is maintained for a predetermined period of time until a mechanically best and fluid-tight connection between the silicone tubes 3a, 3b is achieved.

[0065] For the method shown in Fig. 4 to 6, the first object 1, which can be a housing or cover part, for example, has a connecting piece 9. The connecting piece 9 has a silicone outer surface 10. The silicone outer surface 10 can consist of a silicone layer 11 surrounding a base body of the connecting piece 9 or of a silicone sleeve 12 applied to the base body of the connecting piece 9. The connecting piece preferably has a shoulder 13 which extends upstream of the silicone outer surface 10 in the direction of the free end of the connecting piece 9 and which secures the layer 11 or sleeve 12. In this case, the second object 2 is designed as a silicone hose 3.

[0066] The two objects 1, 2 are first arranged in the radiation area of ​​a radiation source 4 according to Fig. 4.

[0067] According to Fig. 5, both the outer surface 10 of the connecting piece 9 and an inner surface 14 of the silicone hose 3 are then exposed to VUV rays 7. Fig. 5 shows a particular embodiment for the exposure to VUV rays 7, although other configurations are also possible. Here, a radiation source 4a is arranged laterally next to the connecting piece 9. The first object 1 is then rotated about the longitudinal axis of the connecting piece 9, whereby the VUV rays 7 from the radiation source 4a can expose the entire outer surface 10. A further radiation source 4b is used to expose the inner surface 14 of the silicone hose 3. This emits VUV rays 7 through an opening 15 of the silicone hose 3 into an interior space 16 of the silicone hose 3 and then exposes the inner surface 14 of the silicone hose 3.In contrast to the illustrated embodiment, it is even possible for the VUV radiation source 4b, with a lance emitting the VUV rays 7, to extend through the opening 15 into the interior 16 of the silicone hose 3. Once the outer surface 10 of the connecting piece 9 and the inner surface 14 of the silicone hose 3 have been exposed to VUV rays 7 for predetermined periods of time, the silicone hose 3 is slipped over the connecting piece 9 as shown in Fig. 6. The outer surface 10 of the connecting piece 9 and the inner surface 14 of the silicone hose 3 thus form a contact surface, so that they form the connecting areas 6a, 6b. Preferably, the outer diameter of the outer surface 10 has a larger diameter than the inner surface 14 of the silicone hose 3, thus ensuring a contact force in the connecting areas 6a, 6b due to the required elastic radial deformation.

[0068] For the method illustrated in Figs. 8 to 10, an object 1 is designed as a silicone tube 3. The silicone tube 3 is preferably filled with a fluid 17. According to Fig. 7, a force introduction body 18 is arranged between the silicone tube 3 and the radiation source 4. The force introduction body 18 has at least one material region 19 made of a material that is permeable to VUV rays 7.

[0069] According to Fig. 8, the force introduction body 18 is pressed against the outer surface of the silicone hose 3 (for example, by means of an actuator, manually, or due to its own weight). As a result of the force applied by the force introduction body 18 against the outer surface of the silicone hose 3, an elastic and / or plastic deformation of the silicone hose 3 occurs such that, in the circumferential direction of the cross-section of the silicone hose 3, opposing inner surface regions 20a, 20b approach one another and are pressed against one another, thus closing the cross-section of the silicone hose 3. As the silicone hose 3 is compressed by the force introduction body 18, the fluid is laterally forced out of the space between the inner surface regions 20a, 20b. In the compressed state, the VUV rays 7 are applied, as shown in Fig. 8.Here, the VUV rays 7 pass from the radiation source 4 through the force introduction body 18 and through the silicone tube 3 to the connecting regions 6a, 6b formed by the inner surface regions 20a, 20b. Here, too, the connecting regions 6a, 6b are exposed to the VUV rays 7 for a predetermined period of time. It is possible that, after the predetermined exposure period to the VUV rays 7, the pressure of the force introduction body 18 against the silicone tube 3 is maintained for a further predetermined period of time, as shown in Fig. 8. Following this, the force introduction body 18 is removed from the silicone tube 3, as shown in Fig. 9. A permanent mechanical and fluid-tight connection is created between the connecting regions 6a, 6b.

[0070] According to Fig. 10, the silicone tube 3 can then be severed in the connecting areas 6a, 6b, creating two silicone tube pieces 21a, 21b that are fluid-tightly sealed in the end areas shown. The severing can be performed, for example, using a cutting knife or a laser. It is also possible for the force introduction body 18 to have a rib or cutting edge that weakens or severes the silicone tube 3 when pressed against it.

[0071] If a silicone hose 3 is mentioned in the present description, it can also be an inherently rigid, but elastically or plastically deformable silicone tube.

[0072] It is possible for the connection areas 6a, 6b to be exposed to VUV rays 7 in a chamber 22, as shown schematically and in dashed lines in Fig. 1. The chamber 22 can then be filled with an inert fluid, in particular nitrogen, or a technical vacuum can be created in the chamber 22.

[0073] As described, the force introduction body 18 can be made entirely or only in a material region 19 from a material that is permeable to the VUV rays 7. However, it is also possible for the force introduction body to have through-holes in the region of which the VUV rays 7 pass through the force introduction body 18 to the connecting regions 6, while the force introduction body 18 can also have material regions adjacent to these through-holes in which material is present that is impermeable to VUV rays 7. For example, the force introduction body 18 can be designed like a grid or be equipped with numerous bores or recesses.

[0074] Figs. 11 to 15 illustrate an alternative method by which a silicone hose 3 can be separated into two silicone hose pieces 21a, 21b, each of which is sealed fluid-tight in the region of its separation point 23. Here, too, as shown in Fig. 11, the silicone hose 3 is first deformed by means of a force introduction body 18 such that the inner surface regions 20a, 20b, which form the connecting regions 6a, 6b, come into contact with one another (or at least have a reduced distance from one another (Fig. 12). For this exemplary embodiment, the force introduction body 18 is designed in several parts. By means of a separation tool 22, the silicone hose 3 is then severed into the silicone hose pieces 21a, 21b, creating a separation point 23 (cf. Fig. 13).A central force introduction body part 24 is then moved away from the separation point 23 and the end regions 25a, 25b of the silicone hose pieces 21a, 21b, while an adjoining section of the silicone hose pieces 21a, 21b continues to be pressed down and fixed by a force introduction body part 26a, 26b. In the end regions 25a, 25b, the inner surface regions 20a, 20b can spread apart or move apart (in particular as a result of elastic recovery or as a result of the residual stresses from the previous deformation), thus forming, in particular according to Fig. 13, an intermediate space 27a, 27b that opens toward the separation point 23 and can, for example, be wedge-shaped.By means of a radiation source 4, the inner surface regions 20a, 20b in the end regions 25a, 25b are then exposed to VUV rays 7, whereby these VUV rays 7 can reach the inner surface regions 20a, 20b through the end regions of the silicone tube pieces 21a, 21b or (as shown in Fig. 13) through the opening of the intermediate spaces 27a, 27b.

[0075] It is possible that the force introduction body part 24 is subsequently moved down again, whereby the end regions 25a, 25b are then pressed together again to establish the connection. However, Fig. 14 shows another embodiment of the method in which an adhesive, connecting agent, or connecting body 28a, 28b is introduced into the gaps 27a, 27b, which then forms the connection with the associated end region 25a, 25b of the silicone hose pieces 21a, 21b (cf. Fig. 15). The end regions 25 with the adhesive, connecting agent, or connecting body 28 can then each form a bead 29a, 29b. LIST OF REFERENCE SYMBOLS first object second object

[0076] silicone hose

[0077] Radiation source

[0078] frontal surface

[0079] Connection area

[0080] VUV rays

[0081] Contact pressure

[0082] connecting piece

[0083] lateral surface

[0084] layer

[0085] sleeve

[0086] Paragraph

[0087] inner surface

[0088] opening

[0089] Interior

[0090] Fluid

[0091] Force introduction body

[0092] Material area

[0093] Interior surface area

[0094] Silicone hose piece

[0095] Cutting tool

[0096] Separation point

[0097] Force introduction body part

[0098] End area

[0099] Force introduction body part

[0100] space

[0101] Adhesive, fastener or connecting body,

[0102] bead

Claims

PATENT CLAIMS 1. A method for connecting a first connecting region (6a) to a second connecting region (6b), wherein the first connecting region (6a) and the second connecting region (6b) are made of silicone, wherein a) the first and / or the second connecting region (6) are / is exposed to VUV rays (7), b) the connecting regions (6) are pressed against one another or are connected to one another by means of an adhesive, connecting agent or connecting body (28), and c) before and / or during and / or after the exposure of at least one connecting region (6) to VUV rays (7) and / or the pressing of the connecting regions (6) against one another, an elastic and / or plastic deformation of at least one object (1, 2) in the connecting region (6) takes place, characterized in that d) during the exposure of at least one connecting region (6) to VUV rays (7), an elastic and / or plastic deformation of at least one object (1,2) in the connection area (6), which is brought about by means of a force introduction body (18), wherein the force introduction body (18) has a material area (19) which is at least partially transparent to the VUV rays (7), and the at least one connection area (6) to be exposed to the VUV rays (7) is exposed to the VUV rays (7) by a VUV radiation source (4) through the material area (19) of the force introduction body (18).

2. Method according to claim 1, wherein the connecting regions (6) are pressed against one another a) after the first and / or the second connecting region (6) has / has been exposed to VUV rays (7) or b) during which the first and / or the second connecting region (6) is / is exposed to VUV rays (7).

3. Method according to one of the preceding claims, wherein the first and / or second connecting region (6) is exposed to oxygen-free conditions, wherein the first and / or second connecting region (6) is preferably exposed to oxygen in a chamber (22) filled with an inert fluid, in particular nitrogen.

4. Method according to one of the preceding claims, wherein at least one object (1, 2) forming a connecting region (6) is designed as a hollow body with an interior space (16) and the connecting region (6) of this object (1, 2) is exposed to the VUV rays through the interior space (16).

5. Method according to one of claims 1 to 4, wherein the first connecting region (6a) and the second connecting region (6b) are opposite inner surface regions (20a, 20b) of a silicone hose (3) and during the exposure of at least one of the connecting regions (6) to VUV rays (7), an elastic and / or plastic deformation of the silicone hose (3) takes place by means of a force introduction body (18) in such a way that the inner surface regions (20a, 20b) come into contact with one another, wherein the force introduction body (18) has a material region (19) which is at least partially transparent to the VUV rays (7), and the connecting regions (6) to be exposed to the VUV rays (7) are exposed to the VUV rays (7) by a VUV radiation source (4) through the material region (19) of the force introduction body (18).

6. The method according to claim 5, wherein the silicone tube (3) is subsequently severed in the region of the connecting areas (6).

7. A method for connecting a first connecting region (6a) to a second connecting region (6b), wherein the first connecting region (6a) and the second connecting region (6b) are made of silicone, wherein a) the first and / or the second connecting region (6) is exposed to VUV rays (7) and b) the connecting regions (6) are pressed against one another or are connected to one another by means of an adhesive, connecting agent or connecting body (28), characterized in that c) the first connecting region (6a) and the second connecting region (6b) are opposite inner surface regions (20a, 20b) of a silicone hose (3) and are inserted into an intermediate space (27) between the opposite inner surface regions (20) of the silicone hose (3) an adhesive, connecting agent or connecting body (28) is introduced.

8. The method according to claim 7, wherein a) an elastic and / or plastic deformation of the silicone hose (3) is carried out by means of a force introduction body (18) in such a way that the inner surface regions (20a, 20b) come into contact with one another, b) a separation point (23) is created by means of a separation tool (22), which separates the silicone hose pieces (21) from one another, c) a force introduction body part (24) of end regions (25) of the silicone hose pieces (21) is moved away, d) the inner surface areas (20a, 20b) in the area of ​​intermediate spaces (27) adjacent to the separation point are exposed to VUV rays (7) by means of a radiation source (4), and e) an adhesive, a connecting agent or a connecting body (28) is introduced into the intermediate spaces (27), which then forms a connection with the inner surface areas (20).

9. Method according to one of claims 6 to 8, wherein the method is used for sealing a product filled with a fluid (17).

10. A method for connecting a first connecting region (6a) to a second connecting region (6b), wherein the first connecting region (6a) and the second connecting region (6b) are made of silicone, wherein a) the first and / or the second connecting region (6) is exposed to VUV rays (7) and b) the connecting regions (6) are pressed against one another or are connected to one another by means of an adhesive, connecting agent or connecting body (28), characterized in that c) a first object (1) forming the first connecting region (6a) is a first silicone tube (3a) and a second object (2) forming the second connecting region (6b) is a second silicone tube (3b) and the connecting regions (6a, 6b) are end faces (5a, 5b) of the silicone tubes (3).

11. A method for connecting a first connecting region (6a) to a second connecting region (6b), wherein the first connecting region (6a) and the second connecting region (6b) are made of silicone, wherein a) the first and / or the second connecting region (6) are exposed to VUV rays (7) and b) the connecting regions (6) are pressed against one another or are connected to one another by means of an adhesive, connecting agent, or connecting body (28), characterized in that c) a first object (1) forming the first connecting region (6a) is a silicone hose (3), wherein the first connecting region (6a) is an end-side inner surface (14) of the silicone hose (3), a second object (2) forming the second connecting region (6b) has a fluidic connection piece (9) having a lateral surface (10) made of silicone, wherein the lateral surface (10) forms the second connecting region (6b),and after the first and / or second connection area (6) has been exposed to VUV rays (7), the silicone hose (3) is pulled over the connection piece (9), whereby the connection areas (6a, 6b) come into contact with each other., 12. The method according to claim 11, wherein the connecting piece (9) has an oversize compared to the silicone hose (3).

13. The method according to claim 11 or 12, wherein the exposure of the inner surface (14) of the silicone tube (3) to VUV rays (7) takes place through an interior space (16) of the silicone tube (3).

14. Method according to one of claims 7 to 13, wherein a) the connecting regions (6) are pressed against one another after the first and / or the second connecting region (6) has been exposed to VUV rays (7) or during which the first and / or the second connecting region (6) is / are exposed to VUV rays (7), and / or b) the exposure of the first and / or second connecting region (6) takes place free of oxygen, wherein preferably the exposure of the first and / or second connecting region (6) takes place in a chamber (22) filled with an inert fluid, in particular nitrogen, and / or c) before and / or during and / or after the exposure of at least one connecting region (6) to VUV rays (7) and / or the pressing of the connecting regions (6) against one another, an elastic and / or plastic deformation of at least one object (1, 2) in the connecting region (6) takes place, and / or d) at least one object (1, 2) forming a connecting region (6) is designed as a hollow body with an interior space (16), and an exposure of the connecting region (6) of this object (1, 2) with the VUV rays pass through the interior (16).

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