Device, method and capacitor plate set for producing particle foam part, in particular for producing shoe sole or part of shoe sole

Abstract

The invention relates to a device and a method for producing a sole or a part of a sole from foam particles. The device comprises: a.) a molding tool formed from at least two mold halves, which defines a cavity, and b.) at least two capacitor plates, which are arranged adjacent to said cavity, where c.) at least one capacitor plate is connected to a radiation source, and where d.) at least one capacitor plate comprises several segments, the shape and size of the surface of the capacitor plate can be adapted to the shape of the component to be manufactured in the molding tool.

Description

[0001] This application is a divisional application of a Chinese patent application with an application date of April 27, 2022, an application number of 202210453545.2, and an invention title of "Device, Method and Capacitor Plate Group for Manufacturing Granular Foam Components, Particularly for Manufacturing Soles or Parts of Soles". Technical Field

[0002] The present invention relates to a device, a method and a capacitor plate group for manufacturing granular foam components.

[0003] The present invention provides a device, a method and a capacitor plate group for manufacturing granular foam by using electromagnetic waves, wherein foam particles are fused into a granular foam component by electromagnetic waves. The energy required for fusion is applied to the foam particles by electromagnetic waves.

[0004] The device, the method and the capacitor plate group can be particularly used for manufacturing soles or parts of soles, especially mid-soles or parts thereof. The present invention also relates to a sole or a part of a sole manufactured in this way, especially a mid-sole or a part of a mid-sole. Background Art

[0005] A method for sintering wet thermoplastic foam particles is described in US 3,079,723. The particles are dielectrically heated and compressed simultaneously. Electromagnetic waves with a frequency of about 2 to 1000 MHz are applied.

[0006] Document US 3,242,238 describes a similar process. In this method, the foam particles are wetted with an aqueous solution and exposed to an electromagnetic field with a frequency of about 5 to 100 MHz.

[0007] Document GB 1,403,326 describes a method for fusing expandable polystyrene foam particles. In this method, the particles are wetted with an aqueous solution and exposed to an electromagnetic field of 5 to 2000 MHz.

[0008] WO 01 / 064414A1 discloses a method in which polyolefin polymer particles wetted with a liquid medium are heated with electromagnetic waves, especially microwaves. The temperature in the mold is controlled by controlling the pressure in the mold.

[0009] WO 2013 / 050181 A1 describes a method for manufacturing granular foam components, in which a mixture of foam particles and a dielectric transfer liquid is heated by electromagnetic waves to fuse the foam particles into a granular foam component. Radio waves or microwaves are used as the electromagnetic waves. The material of the foam particles is formed by polypropylene (PP).

[0010] Despite these rather substantial efforts over a long period of time, machines for fusing foam particles by means of electromagnetic waves have not been established in industrial manufacturing to date. One of the main reasons is that heat cannot be introduced evenly into the foam particles and a uniform fusion cannot be produced within the particulate foam component.

[0011] Therefore, in commercial applications, machines for fusing foam particles by means of steam have been mainly used to date. However, these machines have the disadvantage of low energy input efficiency. In addition, the particulate foam components remain moist after fusion and thus cannot be further processed immediately. Since the heating is carried out from the outside inwards, the inner parts of the components cannot always be fused to have sufficient quality. Moreover, the devices for generating steam are much more expensive than the generators for electromagnetic waves.

[0012] Fusing foam particles with electromagnetic radiation requires supplying high energy to the foam particles, for which the foam particles are located in a molding tool. In addition, the energy input into the foam particles should be as uniform as possible to achieve uniform heating and thus uniform fusion of the foam particles.

[0013] One problem is that the electrodes and the corresponding molding tools usually have different dimensions. Depending on the product to be manufactured, the molding tools have to be replaced. Therefore, different molding tools are used in the fixture, which can differ in size. The molding tools are usually a little smaller than the electrodes to accommodate the molding tools completely within the electric field of a plate capacitor. Therefore, the electrodes usually protrude a little beyond the sides of the molding tools. This results in unused electric fields. The capacitance of the capacitor is greater than the required capacitance. As a result, the capacitor takes up more charge and thus also absorbs more energy than required.

[0014] Another problem, especially with regard to the manufacture of soles or parts of soles, in particular mid-soles or parts thereof, is the complex three-dimensional geometry of these parts. For example, the sole almost never has a constant thickness along its longitudinal and / or medial to lateral extent. This complicates the fusion process because it is difficult to achieve constant and uniform fusion of the particles over all areas of the sole. Summary of the Invention

[0015] The applicant of this patent application has improved the known devices and methods for fusing foam particles by electromagnetic waves and the corresponding processes, particularly in the context of the manufacture of shoe soles. These devices and methods are based on the technologies described in the published documents DE102016100690 A1 and DE 102016123214 A1 and German patent application No. 102019127680.2, as well as the published applications DE 102015202013 A1 and DE 102016223980 A1 owned by the applicant of this application, in combination with the present invention described below, particularly with regard to devices, methods, and materials, but not exclusively with reference to these documents.

[0016] The present invention is particularly based on the problem of improving the efficiency of energy input and the more effective use of electric fields in the manufacture of particulate foam components, particularly shoe soles / midsoles, by fusing foam particles with electromagnetic waves.

[0017] The present invention is also based on the problem of improving the quality of shoe soles or midsoles manufactured by fusing foam particles using electromagnetic fields, even if they have complex three-dimensional geometries, particularly varying thicknesses.

[0018] These problems are addressed and at least partially solved by different aspects of the present invention discussed in more detail below.

[0019] A first aspect of the present invention provides a device for manufacturing a particulate foam component, particularly a shoe sole or a part of a shoe sole (e.g., a midsole or a part thereof).

[0020] In one embodiment, the device includes a molding tool defining a cavity, wherein at least two capacitor plates are arranged adjacent to the cavity and are connected to a radiation source for electromagnetic radiation, wherein the electromagnetic radiation source is adapted to emit electromagnetic radiation, and the molding tool is formed by at least two half-molds, and at least one of the two capacitor plates is formed by several segments such that the surface of the capacitor plate array having several segments can be adapted based on the shape of the product to be fused in the cavity.

[0021] For example, the capacitor plate formed by multiple segments is designed as a segmented electrode. It can consist of several parts. This is relatively easy to achieve, especially with flat electrodes or capacitor plates. However, not only flat electrodes can be used, but also shaped electrodes, such as electrodes for manufacturing shoe soles / midsoles.

[0022] For example, these segments are shaped in such a way that by removing and / or adding individual segments to form a capacitor plate, the shape and size of its surface, particularly its lateral dimension, can be adapted to the shape of the component to be manufactured in the molding tool.

[0023] Preferably, the sections of the capacitor plates are detachably electrically and mechanically connected. In this way, individual sections can be removed or added to adapt the surface of the capacitor plates to the dimensions of the molding tool.

[0024] Conductive connecting elements can be provided, which electrically connect them at the edges of two or more sections. For example, conductive metal elements such as red copper foil or brass foil can be used, and the edges of the sections of the electrodes are clamped on the conductive metal elements so that there is an electrical connection to all sections of the electrodes.

[0025] Moreover, these sections can have areas at their edges that interlock when the sections are joined together. This means that electrical and mechanical connections can be made particularly reliably and relatively inexpensively at the section joints. For this purpose, the edges or areas can be designed as, for example, stepped seams.

[0026] On the other hand, the sections can also be provided in a non-interlocking manner, especially without such interlocking areas, which can facilitate in-mold assembly, i.e., assembling the sections (or adding or removing one or more sections) without having to disassemble the molding tool / capacitor plates.

[0027] Preferably, the sections are detachably attached to an insulator. The insulator is used to hold the sections in their positions. The insulator is preferably suitable for high voltages and does not cause significant losses of RF radiation, otherwise it will heat up. In addition, the materials used should not show a significant response to the electromagnetic fields used in terms of their field permittivity and dielectric loss, as this will again lead to unwanted heating. Therefore, dielectric materials with a low dielectric loss factor and a low dielectric constant are preferred. For example, ceramic materials and / or plastic materials can be used. Exemplary dielectric polymers that can be used include: PEEK, PTFE, PE, PS, PET. Exemplary ceramic materials that can be used include: alumina, aluminum nitride, aluminum silicate.

[0028] The sections of the electrode or capacitor plates can be attached to the insulator, for example, with screws. However, other fastening means such as plug connections, bolts, clamping elements, etc. can also be used to fasten the sections to the insulator.

[0029] For example, at least one section of the capacitor plate formed by the sections is electrically connected to a radiation source.

[0030] According to one option, the sections of the capacitor plates can be permanently attached to the insulator and can be individually switched on or off to adjust the size of the capacitor plates. This can be done relatively easily, especially if the segmented capacitor plates are flat, or if two flat segmented capacitor plates form a capacitor for exposing particles to radiation.

[0031] In this case, preferably, these segments are electrically isolated from each other and each segment is individually connected to a radiation source, for example via a high-frequency line in the case where a high-frequency generator is used as the radiation source.

[0032] Advantageously, each segment is connected to an adjustable resonant circuit and can be switched on or off, or activated or deactivated, individually or in groups, by tuning the respective resonant circuit.

[0033] In particular, these segments can each form a partial capacitor which is connected to the adjustable resonant circuit.

[0034] Each power line can be assigned a regulating capacitor with which the energy supplied through the respective line can be adjusted independently of one another. By controlling the energy supply on the individual lines, it is thus possible to control which of the segments of the capacitor are operated. By switching the individual segments on and off by means of resonant circuit tuning, the dimensions of the capacitor plates can be adapted to the dimensions of the mould tool with respect to its radiation-emitting surface. This means that it is not necessary to mechanically remove or attach individual segments to adapt the surface of the capacitor plates according to the mould tool.

[0035] Preferably, these segments together form a shaped capacitor plate.

[0036] In particular, the segments can be arranged on both sides of the cavity and, in particular, a segmented capacitor plate is formed there.

[0037] The segments can also be arranged only on one side of the cavity and a segmented capacitor plate is formed there. On the other side of the cavity, for example, a continuous capacitor plate can be arranged.

[0038] Furthermore, on the other side of the cavity, a conductive region or a conductive half-mould of the mould tool can be used as the capacitor plate opposite the segmented capacitor plate. However, in the case of a shaped surface, a non-conductive half-mould is preferred because it is easier to generate a uniform electric field. In addition, using a conductive half-mould entails the risk of burning the manufactured part in the region adjacent to the half-mould, and therefore a non-conductive material is also preferred from this point of view.

[0039] If both half-moulds are conductive, one half-mould would have to be connected to the RF radiation line, which would be relatively difficult to achieve or very expensive to implement.

[0040] It is advantageous if at least one of the capacitor plates formed by these segments is electrically connected to the radiation source while, for example, another capacitor plate or its segments are electrically grounded or earthed.

[0041] In particular, the segments can each have a geometry which, when the segments are combined, gives rise to capacitor plates, the geometry of which (in particular, its lateral extent) is adapted to the geometry and dimensions of the mould tool. For example, the segments can be rectangular, preferably with different dimensions, so as to form rectangles of different sizes as capacitor plates by combining several segments according to the dimensions of the mould tool to be irradiated.

[0042] The edges of adjacent segments are advantageously parallel to one another in order to form capacitor plates by combining several segments.

[0043] In particular, it is advantageous to arrange the individual segments in such a way that a central square segment is provided and additional segments extend along the sides of the square segment. In this way, rectangles of different sizes can be created by combining several segments. A ring of additional segments can be provided.

[0044] For example, the segments can be designed as sheet metal parts. The segments can be flexible. It is advantageous if they are made of a metal with good electrical conductivity or a metal alloy with good electrical conductivity.

[0045] According to a second aspect of the invention, there is provided a capacitor plate set for a device for manufacturing a particulate foam component, in particular a sole or part of a sole (for example, a midsole or part thereof).

[0046] In one embodiment, the capacitor plate set comprises at least one first capacitor plate segment which is adapted to be attached to an insulator and comprises a terminal region adapted to be connected to a radiation source for generating electromagnetic radiation, and one or more second capacitor plate segments, wherein the first capacitor plate segment and the second capacitor plate segments are adapted to jointly form a capacitor plate, the area of which is dimensionally adaptable to the dimensions of a mould tool for manufacturing a particulate foam component.

[0047] The capacitor plate segments form a set of several objects which together form at least one or several segments of capacitor plates, the dimensions of which are adapted to the dimensions of a mould tool for fusing foam particles to manufacture a particulate foam component.

[0048] Preferably, the capacitor plate segments are removably electrically and mechanically connected.

[0049] In particular, the second capacitor plate segments can also each comprise a terminal region for connection to a radiation source for generating electromagnetic radiation.

[0050] Each capacitor plate segment can be designed such that it is electrically isolated from the other capacitor plate segments in the capacitor plate formed by it and can be connected or disconnected from an energy source, for example by means of an adjustable resonant circuit.

[0051] Preferably, the capacitor plate assembly is designed for use in a device according to one aspect of the present invention.

[0052] A third aspect of the present invention relates to a method for manufacturing a particulate foam component, in particular a sole or a part of a sole (e.g., a midsole or a part thereof).

[0053] In one embodiment, the method comprises the steps of: a.) filling foam particles into a cavity of a molding tool, wherein at least two capacitor plates are arranged adjacent to the cavity, the at least two capacitor plates being electrically connected to a radiation source for electromagnetic radiation to generate electromagnetic radiation; b.) fusing the foam particles by the electromagnetic radiation between the capacitor plates; and c.) demolding; wherein d.) at least one of the two capacitor plates is formed of a plurality of segments, and the area of at least one capacitor plate is adapted to the size of the molding tool by combining the radiation generating segments.

[0054] The foam particles are heated in the molding tool such that they are fused to form a particulate foam component. Heat is applied to the foam particles using electromagnetic RF radiation.

[0055] Advantageously, the segments are detachably electrically and mechanically connected to combine them.

[0056] According to an option, the segments can be arranged electrically isolated from each other and can be switched on or off, for example, by tuning a resonant circuit connected to the respective segment, to combine them. This allows the area of the capacitor plate emitting the radiation to be adjusted without having to mechanically remove or mechanically add segments. In particular, this eliminates the need to mechanically separate or connect segments to the radiation source when adjusting the area of the capacitor plate, which would require a great deal of effort.

[0057] In particular, the segments can each form a partial capacitor.

[0058] It is advantageous to carry out the method using the device according to the present invention and / or the capacitor plate assembly according to the present invention.

[0059] The foam particles are preferably made of or contain an expanded thermoplastic material, in particular thermoplastic polyurethane (TPU), polylactate (PLA), polyamide (PA), polyether block amide (PEBA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT) or thermoplastic polyester ether elastomer (TPEE). The foam particles can also be beads containing multiple polymer types in one foam particle, or the foam particles can be a mixture or combination of different particles of different foam polymers. Preferably, 90% by weight of the foam particles consists of one or a mixture of these materials. These foam particles are particles containing so-called bead foams, also known as pellet / particle foams in the art. Generally, the foam obtained by using connected foam particles is in the form of beads of the polymer foam component denoted by the name "e", such as eTPU.

[0060] The foam particles made of these materials are preferably heated mainly by directly absorbing RF radiation. This means that the heat is not or only to a small extent heated by a heat transfer medium such as water, which absorbs the RF radiation and transfers it to the foam particles. On the one hand, the direct absorption of RF radiation is very efficient and also allows the fusion of foam particles made of materials such as polyethylene terephthalate (PET) with a softening temperature above 200 °C (usually around 260 °C), which is impossible to heat with an aqueous heat transfer medium. In addition, the use of such a heat transfer agent can be avoided or reduced, thereby improving the quality of the final product.

[0061] However, within the scope of the present invention, it is also possible to add a heat transfer medium.

[0062] The electromagnetic RF radiation preferably has a frequency of at least 30 kHz or at least 0.1 MHz, in particular at least 1 MHz or at least 2 MHz, preferably at least 10 MHz. The maximum frequency can be 300 MHz. Specific (central) frequencies that can be used and for which the radiation sources are readily commercially available are, for example, 6.78 MHz, 13.56 MHz, 27.12 MHz, 40.68 MHz. However, even (central) frequencies of 2.45 GHz or 5.8 GHz can be used.

[0063] To generate the electromagnetic RF radiation, capacitor plates are preferably arranged on a molding tool, which is additionally made of an electrically insulating material. A high-frequency voltage with an amplitude of approximately at least 1 kV to several kV, preferably at least 10 kV, in particular at least 20 kV, is applied to the capacitor plates.

[0064] At this voltage, power in the range of 10 kW - 60 kW can be transferred to the foam particles in the cavity. This enables even large-volume particulate foam components and / or soles or parts thereof to be reliably manufactured with a very short cycle time of approximately 30 seconds to 2 minutes.

[0065] The foam particles can be compressed in the molding tool. For example, the molding tool can be designed as a crack-gap molding tool. In this case, in addition to the compression effect generated by the thermal expansion of the foam particles during the fusion process, the foam particles are also mechanically compressed.

[0066] The molding tool is preferably made of a material that is substantially transparent to the electromagnetic RF radiation used (e.g., in the sense of a low relative dielectric constant). Possible materials include polytetrafluoroethylene (PTFE), polyethylene (PE), especially ultra-high molecular weight polyethylene (UHMWPE), polyether ketone (PEEK). However, semi-transparent materials such as polyethylene terephthalate (PET), polyoxymethylene (POM), or polyketone (PK) can also be used.

[0067] In the case where the sections can be connected or disconnected individually or in groups to form a capacitor, the electromagnetic radiation source can be designed as part of a generator resonant circuit. The line for guiding the electromagnetic wave forms a tool resonant circuit together with a pair of sections, and each section forms a partial capacitor. By changing the inductance or capacitance, the tool resonant circuit can be tuned and form an adjustable resonant circuit, through which power transmission can be blocked or enabled in a targeted manner.

[0068] The control device for controlling the adjustable resonant circuit can be designed such that power is supplied from the generator resonant circuit to the tool resonant circuit, which can be designed as an adjustable resonant circuit and can be switched on or enabled or interrupted by its tuning. In this way, the relevant sections are added to or removed from the capacitor plates formed by several sections, and the capacitor plates apply electromagnetic radiation to the molding tool during the fusion process.

[0069] Depending on the size of the generator and the line connecting the generator resonant circuit to the adjustable resonant circuit, the power transmitted to the cavity by tuning the resonant circuit can be in the range of 25 kW to 60 kW.

[0070] In all options of the different aspects of the invention discussed here, one of the two capacitor plates can be electrically connected to the ground. The other capacitor plate can be directly connected or connected to the radiation source directly through one or more of its sections, and thus the radiation is fed to the capacitor plate as an electromagnetic wave relative to the ground plane.

[0071] The fourth aspect of the present invention can be combined with the above-mentioned first, second, and / or third aspects of the present invention and all possible alternatives, modifications, and embodiments thereof (of course, if not physically or technically excluded), which are provided by a device for manufacturing particulate foam components, in particular a sole or a part of a sole (e.g., a midsole or a part of a midsole).

[0072] In one embodiment, the device comprises: a.) a molding tool formed by at least two half-molds, which define a cavity; b.) at least two capacitor plates, which are arranged adjacent to the cavity; where c.) at least one capacitor plate is connected to a radiation source; and where d.) at least one capacitor plate comprises several sections having an adaptable distance from the cavity.

[0073] We note that the capacitor plates being arranged "adjacent" to the cavity does not mean that the capacitor plates directly contact the wall of the cavity or form the wall of the cavity. Instead, what this feature implies is that the capacitor plates are arranged "around" the cavity and are at a certain distance from the cavity, which allows the cavity to be flooded or irradiated with an alternating electromagnetic field suitable for generating the desired fusion of foam particles within the cavity. Typically, for example, components or parts of the molding tool (in particular, parts that are permeable or substantially permeable to the electromagnetic radiation used) will be arranged between the capacitor plates and the cavity (see, for example, the detailed discussion of possible embodiments regarding the figures in the following sections), and the shape and dimensions of the cavity are defined by the molding tool, rather than by the capacitor plates themselves (which makes it possible to generally use different molding tools with different cavities between the same set of capacitor plates).

[0074] In the disclosed device, the plurality of sections (also referred to hereinafter as "electrode elements") are designed in such a way as to allow manual or automatic shape changes of the corresponding capacitor plates (also referred to hereinafter as "electrodes"). These shape changes are used to locally control the electric field strength within the cavity and thus control the material heating at said positions, as will be further explained in more detail below. This modularity brings benefits in terms of manufacturing and the product.

[0075] Previous efforts in mold development focused on complex electrode designs guided by precise simulations, aiming to match the electromagnetic field in the cavity as closely as possible to the desired value by directly designing the electrodes / capacitor plates. Since particle fusion by electromagnetic radiation (especially RF radiation) is based on the dielectric heating of the target material, the uniformity of heating depends on the uniform electric field distribution at the operating frequency. This field is typically generated between (at least) two conductive electrodes / capacitor plates, one active and the other grounded, with the insulating molding tool and the target part (here: the sole or a part of the sole) located between these two conductive electrodes / capacitor plates. Usually, the conductive metal electrodes / capacitor plates are partially shaped to adjust the field distribution to accommodate the disturbances caused by the molding tool and the molded part. If this shaping is incorrect, multiple parts of the tool have to be changed to optimize the electrode design. Moreover, the electrode shape cannot be changed during the process or between process cycles to adapt to changed product requirements or material variations.

[0076] In contrast, the disclosed device allows for a flexible change of the tool settings, especially regarding the distance between the active and passive electrodes / capacitor plates, and especially in terms of the grid resolution. Depending on the actuation selected, this change can be manual or active. For the part currently being manufactured, the change is fixed or even changed during the process to allow for more control than currently available. For example, depending on the grid resolution selected, the field strength can be increased or decreased locally and thus the heating rate and maximum temperature experienced by the target can be set. This enables, for example, a quick adaptation to new mold geometries and locally adjusted part characteristics.

[0077] Accordingly, at least one electrode / capacitor plate is divided into a set of elements or segments (e.g., a grid of such elements / segments) that can be moved parallel to the z-axis, which is placed along the direction from the electrode / capacitor plate towards the cavity, but preferably still always electrically connected to the main body of the electrode (which is the active or passive side, preferably the passive side), which is then further connected to the radiation generator or the ground potential (preferably the ground potential as this allows for a simpler construction). The distance between the electrode elements / segments and the cavity and thus the distance between the opposing electrodes / capacitor plates affects the local field strength in the gap between the two electrodes / capacitor plates and thus the local field strength in the cavity. This distance can be set by any form of actuator and the distance control can be carried out at the level of individual segments. In particular, all elements can always be kept in electrical contact and the segment control system does not interfere with the electromagnetic fusion process.

[0078] For example, a set of tests was conducted using an aluminum circuit board with a screw array fixed thereto. The screws were manually set to different heights. For the fusion of expanded thermoplastic polyurethane (eTPU) particles, distinct differences in heating rate and maximum temperature were achieved for different electrode configurations. The characteristics of the manufactured parts also changed locally and correspondingly.

[0079] In summary, by using the disclosed device, improved prototype / part quality can be achieved, and it is highly suitable for product testing and / or prototype development. Thus, faster process development of new products can be realized, and lower-cost tools can be used. During the fusion process, changing the distance from the section to the cavity, as well as the distance between the two electrodes / capacitor plates, can also allow new process optimization methods, thereby enabling product optimization.

[0080] Further details, options, and embodiments of such a device, as well as some related technical advantages, are discussed below.

[0081] As already mentioned, these sections can be electrically connected to a conductive electrode body. The electrode body can especially be at ground potential.

[0082] In particular, the capacitor plate connected to a radiation source (e.g., a generator for RF radiation) can be the first capacitor plate on one side of the cavity, and the capacitor plate including several sections with an adaptable distance from the cavity can be the second capacitor plate on the opposite side of the cavity.

[0083] For example, as initially stated, the "active" capacitor plate connected to the radiation source and the "passive" capacitor plate including adjustable sections can be arranged on opposite sides of the cavity, enclosing the cavity therebetween, and by effectively adjusting the distance from the section to the cavity, the distance between the two capacitor plates also changes locally. In the cavity, this results in a change in the field strength distribution of the electromagnetic field filling the cavity, and thus a change in the field strength distribution at the surface of the particles being fused under the influence of the electromagnetic field.

[0084] The distance from the section to the cavity can be adjusted individually by mechanical and / or electro-mechanical actuator devices.

[0085] In particular, the sections can be arranged in a two-dimensional grid, especially a rectangular grid.

[0086] The grid density (i.e., the number of adjustable sections per unit area) can also vary locally. For example, corresponding to the toe region and / or the heel region of the sole to be manufactured, the sections can be arranged with an increased density compared to other parts of the sole to allow an even higher degree of control of the fusion process in these regions.

[0087] Alternatively or additionally, in order to vary the density of the arrangement of the segments, it is also possible to locally vary the surface area from which they emit radiation. For example, screws or pins with different head sizes can be used (generally: smaller head sizes in the regions of the segments with higher density).

[0088] As just described, these segments can be provided as screws or pins that are adjustably connected to the electrode body. The screws can be, for example, metal screws that are screwed into the electrode body, and the electrode body can also be made of metal or include metal, such as aluminum.

[0089] A cover sheet or covering layer of non-conductive material can be further arranged on the electrode body and includes openings in which the screws or pins are provided.

[0090] Such a cover sheet can be used to increase the stability of the arrangement of the segments themselves, for example by providing lateral stability to the segments, especially when they extend a long distance from the electrode body (e.g., if the screws are screwed out of the substrate almost to their full length). But it can also be used to provide a stable platform on which other parts of the molding tool located between the electrode / capacitor plate and the cavity can be positioned. Without such a plate or layer, the adjustable position of the segments would result in a varying support surface for adjacent components of the molding tool, which would not only require a more complex construction but could also be detrimental to the stability of the tool.

[0091] Such a cover sheet can be made of or include an electrically insulating cover. Preferably, the cover sheet is made of or contains one or more of the following materials: polytetrafluoroethylene (PTFE), polyethylene (PE), especially ultra-high molecular weight polyethylene (UHMWPE), polyetheretherketone (PEEK), thermoplastics, duroplast, polyethylene terephthalate (PET), polyoxymethylene (POM), polystyrene (PS), insulating mineral materials.

[0092] One option is that each adjustable segment can be set to at least one of the following four positions: removed or electrically disconnected, low position, intermediate position, high position.

[0093] For example, the adjustable segment can be electrically disconnected by tuning a resonant circuit as disclosed herein with respect to other aspects of the invention and / or by a simple switching-type element.

[0094] In addition to being adjustable to a predetermined position, some or all of the segments can also be continuously adjusted in their position (i.e., any position between the lowest and highest positions).

[0095] Having a limited set of predefined positions facilitates the operation of the device, while the possibility of having continuously adaptable section positions (in the z-direction, i.e., towards and away from the cavity) increases the amount of influence and control that can be exerted on the electromagnetic field intensity distribution.

[0096] When irradiating or filling the cavity with electromagnetic radiation, the position of the sections can be adjusted. Again, by their "position" is meant the position or height of the sections in the z-direction. In other words, changing the position of the sections changes their distance to the cavity.

[0097] As described and explained above, adjusting the position of one or more sections, i.e., their distance to the cavity and thus usually also their distance to the opposite electrode / capacitor plate, influences the field strength distribution of the radiated electromagnetic field in the cavity.

[0098] Furthermore, the shape of the capacitor plate connected to the radiation source can be at least partially adapted to the geometry of the part to be manufactured (i.e., the sole or a part of the sole, such as the midsole or a part thereof).

[0099] A fifth aspect of the invention relates to the fourth aspect and can also utilize or rely on any options, embodiments, and examples disclosed in the context of the first, second, and / or third aspects of the invention, and is a method for manufacturing a sole or a part of a sole from foam particles.

[0100] In one embodiment, the method comprises: a.) loading the particles into a cavity of a molding tool, the molding tool being formed by at least two half-molds defining the cavity, wherein at least two capacitor plates are arranged adjacent to the cavity, wherein at least one of the capacitor plates is connected to a radiation source, and wherein at least one of the capacitor plates comprises several sections having an adaptable distance to the cavity; b.) irradiating the cavity with electromagnetic radiation emitted by the capacitor plates; and c.) locally adjusting the field strength distribution of the irradiated electromagnetic field in the cavity by changing the adaptable distance of the sections to the cavity.

[0101] The change can occur before and / or during the irradiation of the cavity with electromagnetic radiation.

[0102] The foam particles are preferably made of or contain expanded thermoplastic materials, in particular thermoplastic polyurethane (TPU), polylactide (PLA), polyamide (PA), polyether block amide (PEBA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT) or thermoplastic polyester ether elastomer (TPEE). The foam particles can also be beads containing multiple polymer types in one foam particle, or the foam particles can be a mixture or combination of different particles of different foam polymers. Preferably, 90% by weight of the foam particles consists of one or a mixture of these materials. These foam particles are particles containing so-called bead foams, also known as pellet / particle foams in the art. Generally, the foam obtained from the use of connected foam particles is in the form of beads of the polymer foam component, denoted by the name "e", such as eTPU.

[0103] It is mentioned that such foam particles are also known in the art as particles of expanded materials, which are materials that have already been foamed (compared to expandable materials that are capable of foaming but have not yet foamed). In other words, the particles already have a core of foam material before being inserted into the mold. BRIEF DESCRIPTION OF THE DRAWINGS

[0104] Examples of how to implement the present invention are explained in more detail below with the aid of the drawings. In addition, express reference is made to the published documents DE 102016100690 A1 and DE 102016123214 A1 owned by the applicant of the present application and German patent application No. 102019127680.2, as well as the published applications DE 102015202013 A1 and DE 102016223980 A1, in which devices and methods further developed and improved by aspects of the present invention are described in detail.

[0105] The included drawings show the following:

[0106] Figure 1 Schematically shows an example of a device for manufacturing a particle foam component;

[0107] Figure 2 Is a schematic diagram of a section arrangement forming two opposing capacitor plates for manufacturing a particle foam component;

[0108] Figure 3 Schematically shows the arrangement of the interconnecting sections in a sectional view;

[0109] Figure 4 Shows the arrangement of the sections in a schematic diagram of the capacitor plate surface, which together form the capacitor plate;

[0110] Figures 5 - 8 Shows different devices for manufacturing particle foam components according to different embodiments of the present invention;

[0111] Figure 9 Figure 9 shows an arrangement for exposing a molding tool to electromagnetic radiation according to another embodiment of the present invention in a schematic form;

[0112] Figure 10 Figure 10 Schematically shows an equivalent circuit diagram of an arrangement for a section, each section being individually connected to a radiation source for generating electromagnetic radiation;

[0113] Figure 11 Figure 11 Shows a switching device for connecting or disconnecting capacitor plate sections to or from capacitor plates to emit electromagnetic radiation;

[0114] Figure 12 Figure 12 Shows a control device for controlling a power supply in a circuit diagram; and

[0115] Figure 13a Figure 13a -f shows a part of a device having capacitor plates, the capacitor plates comprising several sections having an adaptable distance from the cavity, and corresponding measurement results obtained from several tests performed on such a device. Detailed Description

[0116] Figure 1 Figure 1 Shows a possible design of a device 1 for manufacturing particulate foam components, in particular a sole or midsole or a part of a sole / midsole. The device 1 comprises a material container 2, a molding tool 3 and a pipeline 4 leading from the material container 2 to the molding tool 3.

[0117]

[0117] The material container 2 is for holding loose foam particles. The material container 2 has a base 5 and is connected in the base 5 to a compressed air source 7 via a compressed air pipeline 6. The compressed air pipeline 6 is connected to several nozzles (not shown) arranged in the base 5 so that several air streams (= fluidizing air) can be introduced into the material container 2, and the air streams cause the foam particles accommodated therein to rotate around them and thereby separate them.

[0118]

[0118] An opening is formed in the region of the base 5 of the material container 2, and the conveying pipeline 4 is connected to this opening. This opening can be closed by means of a slide valve (not shown).

[0119]

[0119] Adjacent to the material container 5 is a propulsion nozzle 8 in the conveying pipeline 4, which is connected to the compressed air source 7 via another compressed air pipeline 9. The compressed air supplied to this propulsion nozzle 8 serves as conveying air because it enters the conveying pipeline 4 through the propulsion nozzle 8 and flows in the direction of the molding tool 3. This creates a negative pressure at the propulsion nozzle 8 on the side facing the material container 2, which sucks the foam particles out of the material container 2.

[0120] The conveying line 4 leads to the filling syringe 10 which is connected to the molding tool 3. The filling syringe 10 is connected to the compressed air source 7 via another compressed air line 11. On the one hand, the compressed air supplied to the filling syringe 10 is used to fill the molding tool 3 by applying the compressed air to the foam granule stream in the direction of the molding tool 3. On the other hand, the compressed air supplied to the filling syringe 10 can also be used to blow the foam granules back from the conveying line 4 into the material container 2 when the filling process at the molding tool 3 is completed.

[0121] The molding tool 3 is formed by two half - molds 12, 13. At least one cavity 14 is defined between the two half - molds 12, 13, and the filling syringe 10 leads into this cavity to introduce foam granules. By bringing the two half - molds 12, 13 together, the volume of the cavity 14 can be reduced. When the half - molds 12, 13 move apart from each other, a gap is formed between the half - molds 12, 13, and this gap is referred to as the crack gap. Therefore, such a molding tool 3 is also called a crack - gap mold.

[0122] Capacitor plates 15, 16 are respectively arranged on each of the half - molds 12, 13. These capacitor plates 15, 16 are respectively made of materials with good electrical conductivity such as copper or aluminum. The filling syringe 10 is located on the half - mold 13. The filling syringe 10 extends through a groove in the capacitor plate 16 mounted on the half - mold 13.

[0123] Each of the two capacitor plates 15, 16 is formed by a plurality of segments 85, 86 which are arranged adjacent to each other and are electrically and mechanically connected to each other. The segments 85, 86 are detachable from each other.

[0124] By adding or removing individual segments 85, 86, the size of the first capacitor plate 15 formed by the segments 85 and the size of the second capacitor plate 16 formed by the segments 86 can be adapted to the size of the molding tool 3. In this way, molding tools 3 of different sizes can be arranged between the capacitor plates 15, 16. This enables electromagnetic radiation to be generated between the capacitor plates 15, 16, particularly only in the region of the cavity 14. In regions where electromagnetic radiation is not required for fusing the foam granules, the generation of electromagnetic radiation can be avoided by removing individual segments 85, 86.

[0125] The segments 85, 86 are each attached to insulators 80, 81 and form two opposing segment arrangements. The insulators 80, 81 are used to hold the segments 85, 86 in positions on two opposite sides of the molding tool 3.

[0126] Insulators 80, 81 to which sections 85 and 86 are attached are mounted such that they can move relative to each other. This means that the half - molds 12, 13 of the molding tool 3 together with the segmented capacitor plates 15, 16 resting against the sides of the molding tool 3 can move towards and away from each other. Additionally, when the section arrangements 85, 86 move apart from each other, the molding tool 3 can be replaced.

[0127] Alternatively, sections 85, 86 can also be attached to the molding tool 3 such that they can be detached from the molding tool 3 and from each other. In this case, two insulators 80, 81 or at least one of them can be omitted.

[0128] One of the sections 85 is connected to a generator 18 via a wire 17 for transmitting a high - frequency voltage that forms an AC voltage source. The electrical connection of the sections 85 to each other causes the high - frequency voltage to be applied to them, thereby forming capacitor plates 15.

[0129] The section 86 on the opposite side of the half - mold 13 that forms the capacitor plate 16 is electrically connected to ground 30, as is the generator 18. Since these sections 86 are also electrically connected to each other, only one of these sections is connected to ground 30.

[0130] The generator 18 is a source of electromagnetic radiation. The generator is preferably designed to generate RF radiation. The generator can also be designed to generate microwave radiation. In the case of a larger cavity 14, RF radiation can be used to heat the molding tool 3 more uniformly than microwave radiation. Additionally, most plastic materials can absorb RF radiation better than microwave radiation. Therefore, RF radiation is preferably used.

[0131] Each of the half - molds 12, 13 has a base body that can be made of a non - conductive material and especially a material that is substantially transparent to electromagnetic RF radiation, such as polytetrafluoroethylene (PTFE), polyethylene (PE), especially ultra - high - molecular - weight polyethylene (UHMWPE), polyetheretherketone (PEEK). Preferably, only the capacitor plates 15, 16 are conductive. A "substantially transparent material" is a material that can be penetrated by electromagnetic radiation, especially RF radiation. However, the material can be specifically designed to have a certain electromagnetic RF radiation absorption coefficient to convert part of the electrical RF radiation into heat and heat the half - molds 12, 13. This will be explained in more detail below.

[0132] The molding tool 3 can be selectively connected to a vacuum pump so that a vacuum can be applied to the cavity 14. This vacuum causes the moisture contained in the cavity 14 to be pumped out.

[0133] The capacitor plates 15, 16 can be equipped with a cooling device. In this example, the cooling device is provided by a fan 20, which guides the cooling air to the side of the capacitor plates 15, 16 facing away from the cavity 14. Cooling fins can be provided to enhance the cooling effect.

[0134] Alternatively or additionally, cooling pipelines can also be arranged on the capacitor plates 15, 16, through which the cooling medium passes. The preferred cooling medium is a liquid, such as water or oil.

[0135] The device 1 can also be designed to have a steam generator and a steam supply device leading to the cavity 14 and / or the conveying pipeline 4 to supply saturated dry steam to the cavity 14 for heating and / or wetting the foam particles during the conveyance of the foam particles from the material container 2 to the cavity 14. The foam particles located in the material container 2 can also be wetted with water in liquid form. For this purpose, corresponding nozzles can be arranged in the material container 2, which evaporate the water.

[0136] To illustrate further details of the device 1, Figure 2 a partial enlarged cross-sectional view of the device 1 is schematically shown. However, in this example, different from Figure 1 the example shown, as an alternative, each section 86 of the second capacitor plate is connected to the ground 30. In all other respects, Figure 1 the description given in Figure 2 also applies to

[0137] Fasteners 82, preferably designed as screws, are used to detachably fasten the sections 85, 86 to the corresponding insulators 80 or 81.

[0138] The conductive connection elements 83 are designed as conductive, flexible metal elements in the form of foils, such as copper foil or brass foil, for electrically connecting the sections 85 arranged adjacent to each other to form the first capacitor plate 15.

[0139] The connection element 83 electrically connects two or more adjacent sections 85 at its edges. When the section 85 is fastened to the insulator 80, the conductive connection element 83 is pressed against the edge of the section 85. This creates an electrical connection for the capacitor plate 15 between its sections 85.

[0140] In the example shown here, due to the grounding of the individual sections 86 on the plate 16, the connection elements 83 are not absolutely necessary on the second capacitor plate 16, but they can optionally be provided and arranged here in the same manner as on the first capacitor plate 15.

[0141] On the contrary, in Figure 1In the example shown, they are arranged on two capacitor plates 15, 16, since only one in the section 86 of the capacitor plate 16 is connected to the ground 30.

[0142] A wire 17 designed as a high-frequency line connects one of the sections 85 to a generator 18 (see Figure 1 ). The section electrically connected to the generator 18 is designed as a high-frequency connection section or a generator connection section 87. Due to the electrical connection between adjacent sections 85, the entire section arrangement 85 is electrically connected to the generator 18 and forms the first capacitor plate 15.

[0143] In this way, the sections 85 form a capacitor plate group 90, which is combined such that the first capacitor plate 15 can be formed, which can be connected to an RF radiation source and whose size can be adapted to the size of the molding tool 3. The capacitor plate 15 can also be adapted to the size of the cavity 14 within the molding tool 3.

[0144] The section 87 designed as an RF connection section and including a connection area for the line 17 to connect to the generator 18 forms the first capacitor plate section of the capacitor plate group 90.

[0145] The other sections 85 form a second capacitor plate section for forming the capacitor plate 15, that is, the first capacitor plate section 87 and at least one second capacitor plate section 85 are designed to form the capacitor plate 15 together and form the capacitor plate group 90. The area of the capacitor plate 15 that can be generated by the capacitor plate group 90 can be adapted to the size of the molding tool 3 for manufacturing particulate foam components (such as soles or midsoles or parts thereof).

[0146] The first capacitor plate section 87 and the second capacitor plate section 85 are designed to be fastened to the insulator 80 using a fastener 82.

[0147] The section 86 of the second capacitor plate 16 arranged opposite the first capacitor plate 15 forms an additional capacitor plate section of the capacitor plate group 90. The additional capacitor plate section 86 complements the capacitor plate group 90 by enabling the generation of the second capacitor plate 16 and thus allows for the formation of a complete capacitor (by the first and second capacitor plates 15, 16). They are designed for mounting on the insulator 81.

[0148] Both insulators 80, 81 can be components of the capacitor plate group 90.

[0149] In the example shown here, a press 73 is also shown, which is connected by a cylinder-piston unit 76 to an insulator 80 located on one side of the molding tool 3. An insulator 81 located on the opposite side of the molding tool 3 is fixed, so that the molding tool 3 can be squeezed together between two capacitor plates 15, 16, which are connected to the insulators 80, 81 on the side facing the molding tool 3.

[0150] Thus, the foam particles in the cavity 14 of the molding tool 3 designed as a crack gap mold can be compressed during their exposure to electromagnetic radiation. In this way, the foam particles are not only squeezed together due to their thermal expansion caused by electromagnetic heating, but also by mechanically squeezing together the two half-molds 12, 13 of the molding tool 3.

[0151] Figure 3 Another possible way of connecting adjacent sections 85 and 86 of the capacitor plates 15 and 16 is shown, as they are shown in Figure 1 and 2 and also shown in subsequent other embodiments. Each of the sections 85, 86 has an edge region 88 protruding from the section body at its edge, and the edge regions are designed such that they interlock when the sections 85, 86 engage with each other. The edge regions 88 form a stepped joint at the junction of the sections 85, 86. In this way, a particularly reliable electrical and mechanical connection is produced between the sections 85, 86, which can also be achieved very cost-effectively.

[0152] Figure 4 An example of the arrangement of the sections 85, 86 is shown, which respectively form the capacitor plate 15 and the capacitor plate 16 and can be produced by a capacitor plate group 90. This figure shows a view of the surface of the capacitor plate.

[0153] In this arrangement, a central section 89 is arranged in the center and is surrounded by additional sections 91. The central section 89 has a square shape. The additional sections 91 each extend along one side of the central section 89 and along one side of another additional section.

[0154] In the example shown here, in addition to the central section 89, a first additional section 91 is provided, which extends along one side of the square. A second additional section 91 extending along the other side of the square and along one side of the first additional section 91 is provided, a third additional section 91 extending along the other side of the square and along the second additional section 91 is provided, and a fourth additional section 91 extending along the remaining side of the square and along both sides of the additional section 91 is provided.

[0155] In this way, by combining several sections 85, 86 as capacitor plate surfaces, different rectangles can be formed. Additionally, additional sections can be provided to complete the arrangement or to surround the arrangement in the form of a ring of additional sections. The central section 89 can also be formed as a rectangle.

[0156] In addition to rectangles and squares, other different dimensions, shapes, and geometries of the sections 85, 86 are possible, and thus capacitor plates of various shapes can be obtained.

[0157] Below, based on Figures 5 - 9 the following, other embodiments of the present invention will be explained, where the same, similar, or functionally equivalent elements are again labeled with the same reference numerals as in the previous figures and have been explained above.

[0158] According to Figure 5 the molding tool 3 of the device 1 consists of two half - molds 12, 13, each half - mold having a matrix made of a non - conductive material that is permeable, especially permeable to electromagnetic RF radiation. The material is PTFE, PE, PEEK, or another material permeable to RF radiation. The half - molds 12, 13 define a cavity 14. In this design example, the cavity 14 has an inner boundary surface 19 that has a contoured shape deviating from a flat surface.

[0159] The half - molds 12, 13 each have a flat outer surface 21 on which the capacitor plates 15, 16 are arranged. The space between the contoured boundary surface 19 and the outer surface 20 is filled with a material permeable to electromagnetic radiation.

[0160] Using this molding tool 3, three - dimensionally contoured particulate foam components can be manufactured, whereby the shape of the particulate foam component is defined by the inner boundary surface 19 of the half - molds 12, 13. Such a molding tool 3 is suitable for, for example, manufacturing small particulate foam components with a substantially uniform density. It can also be used for manufacturing shoe soles or mid - soles or parts thereof.

[0161] The capacitor plates 15, 16 are flat and are designed as described above with reference to Figures 1 - 4 The first capacitor plate 15 is formed by adjacent sections 85. The second capacitor plate 16 is also composed of adjacent sections 86.

[0162] Each set of sections 85 and 86 is respectively attached to insulators 80 and 81 by fasteners 82, whereby the sections 85 of the first capacitor plate 15 are mechanically and conductively, detachably connected to each other, as explained above with reference to Figure 2 and 3 Similarly, the sections 86 of the second capacitor plate 16 are mechanically and conductively, detachably connected to each other.

[0163] The sections 85, 86 and optionally also the insulators 80, 81 are components of the capacitor plate group 90 as described above.

[0164] The problem with large or thick particulate foam components is that they heat more in the middle than at the edges, which can damage the particulate structure. To avoid non-uniform heating of the central and edge regions of the particulate foam component, the molding tool 3 can be tempered and / or additional heat can be added to the foam particles within the cavity 14, for example in the edge regions, as described in DE102016100690 A1.

[0165] By improving the device 1, which will be explained in more detail below, the individual sections 85, 86 can be disconnected even before the end of the fusing process to prevent the foam particles located between the individual sections from overheating.

[0166] The above-described embodiments each have flat capacitor plates 15, 16. In another embodiment, the molding tool 3 can be designed such that the capacitor plates 15, 16 are adapted to the shape of the particulate foam component or the cavity 14 to be manufactured. This is beneficial for the manufacture of, for example, a sole or midsole or parts thereof having a complex three-dimensional geometry to promote uniform fusing of the foam particles throughout the component.

[0167] Figure 6 The illustrated embodiment of the device 1 has two half-molds 12, 13 which define a stepped cavity 14 by their inner boundary surfaces 19. The outer surfaces 21 of the half-molds 12, 13 are adapted to the contour of the respective inner boundary surfaces 19 of the respective half-molds 12, 13. In other words, the inner boundary surfaces 19 are in mirror image to the respective outer surfaces 21 of the half-molds 12, 13, so that the molding tool 3 can have a uniform thickness from the outer surface 21 to the inner boundary surface 19. On the outer surface 21, preferably, the small structures of the inner boundary surface 19 are smoothed out.

[0168] Thus, the molding tool 3 has two shaped half-molds 12, 13, and the correspondingly shaped respective segmented capacitor plates 15, 16 rest on their outer surfaces 21, said capacitor plates being formed by several sections 85 or 86 and otherwise designed as described above with reference to Figures 1 - 5 and as described.

[0169] This adaptation of the shape of the capacitor plate having sections 85, 86 to the shape of the particulate foam component to be manufactured is particularly useful for shell-shaped particulate foam components (such as a box or bowl having spherical sections), or, as described above, for a sole or midsole or parts thereof.

[0170] Also in the example shown here, insulators 80, 81 are used to hold segments 85, 86 in their positions. The side of the insulator facing the half - mold is adapted to the shape of the outer surface 20 of the half - molds 12, 13.

[0171] Figure 7 Another embodiment is shown, in which the first capacitor plate 15 formed by segment 85, together with the insulator 80 and the pressing tool formed by the press 73 and the cylinder - piston unit 76, is generally as described above with reference to Figures 1 - 4 arrangement. With particular reference to Figure 2 and the associated description.

[0172] In this embodiment, the molding tool 3 has a first half - mold 12 and a second half - mold 13, which form a cavity 14 therebetween, in which foam particles 29 to be fused are arranged. In addition to the description of the molding tool 3 now following, reference is also made to German patent application 102019127680.2, in which further details of the molding tool 3 are explained.

[0173] The second half - mold 13 or at least a part thereof is conductive or made of a conductive material. The molding tool 3 can be used as part of the device 1, where the second half - mold 13 serves as the second capacitor plate and is electrically connected to ground 30 for this purpose.

[0174] The second half - mold 13 has a base body 24 made of a conductive material. The base body 24 is composed of, for example, aluminum, copper or an alloy with good electrical conductivity. It is optionally provided with an electrically insulating coating 28 and forms the bottom wall 31. The conductive base body 24 has an electrical connection to the generator 18 or to ground 30.

[0175] The generator 18 (see Figure 1 , 5 and 6) which is electrically connected to the segmented capacitor plate 15 via the high - frequency line 17 generates electromagnetic waves or an alternating voltage with respect to the ground potential 30, which electromagnetic waves or alternating voltage are applied to the base body 24 of the second half - mold 13. This generates an alternating electromagnetic field, in particular RF radiation, in the cavity 14 between the segmented capacitor plate 15 and the base body 24.

[0176] The circumferential side wall 32 of the second half - mold 13 is formed of a non - conductive material, in particular a plastic material, and extends from the bottom wall 31 and on the side of the half - mold 13 in the direction of the first half - mold 12, thus laterally restricting the cavity 14.

[0177] However, it is also possible that both the bottom wall 31 and the side wall 32 are formed by the conductive base body 24. However, it is important that there is no conductive connection between the two half - molds 12, 13.

[0178] The first half - mold 12, located on the side of the molding tool 3 facing the segmented capacitor plate 15, is made of a non - electrically insulating material as described above.

[0179] The first half - mold 12 forms a plunger that can enter a cavity formed by the second half - mold 13, thereby sealing the cavity 14. The tight seal between the two half - molds 12, 13 is at least tight enough to prevent the escape of foam particles 29. However, the cavity 14 does not have to be hermetically sealed.

[0180] The first half - mold 12 has an inner boundary wall 34 that is shaped and defines the cavity 14. Starting from the boundary wall 34, several partitions 35 extend in the direction of the first capacitor plate 15 towards an optional cover element 37. The partitions 35 are used to support the boundary wall 34. Cavities 36 are formed between the partitions 35 in the first half of the mold 12, which significantly reduces its mass.

[0181] This results in a beneficial reduction in the influence on the electromagnetic field strength in the cavity 14, which significantly improves the flexibility of use and shaping of the cavity 14 as well as the plunger half - mold 12.

[0182] In addition, in addition to the flexibility obtained by changing or adjusting the surface of the capacitor plate 15 through different combinations of segments 85, the cavities 36 can also be used to trim the plunger half - mold 12 to affect the electromagnetic field in the cavity 14. The trimming can also be used to achieve a particularly consistent or uniform distribution of the field strength in the cavity 14.

[0183] A trim body (not shown in the figure) made of a dielectric material can also be inserted into the cavities 36. Due to the polarization properties of the dielectric, the alternating electromagnetic field is concentrated by the dielectric in the field paths in the adjacent regions of the cavity 14. In the regions along the same field path that are kept empty by the dielectric, the field is not concentrated in the adjacent regions of the cavity 14, such that the field is weaker in this region of the cavity 14 than in the regions of the cavity 14 adjacent to the dielectric. By using trim bodies of different sizes, shapes, and dielectric constants, the electric field can thus be additionally affected in different ways. The dielectric constant of the dielectric is greater than that of vacuum or air.

[0184] All these measures additionally contribute to the fact that the electromagnetic field is particularly targeted, which results in an even further increased effectiveness of the disclosed device and promotes the uniform fusion of the particles throughout the part, also for complex geometries such as those encountered with, for example, shoe soles or midsoles or parts thereof.

[0185] The two half - molds 12, 13 can be moved relative to each other by a press 73, and a predetermined force can be applied to them. For this purpose, the press 73 is connected to an insulator 80 through a cylinder - piston unit 76, to which the first capacitor plate 15 formed by the segments 85 is attached, as described above with reference toFigure 2 As described. To press two half - molds 12, 13 together, the first half - mold 12 is moved in the direction of the second half - mold 13 by a movable segmented capacitor plate 15 by means of a press 73.

[0186] There is a through - hole for inputting foam particles 29 on the second half - mold 13, and this through - hole is called a filling opening 33. A filling syringe 10 (see Figure 1 ) is connected to the filling opening 33. The filling syringe 10 is different from a conventional filling syringe in that it does not have a closing mechanism for closing the filling opening 33, as will be explained in more detail below.

[0187] The first half - mold 12 has one or more through - holes (not shown in the figure) to allow air to escape.

[0188] The filling opening 33 and the ventilation opening are arranged on a part or region of the second half - mold 13, especially on the edge region, which is covered by the first half - mold 12 when the molding tool 3 is closed. Thus, when the molding tool 3 is closed by inserting the first half - mold 12 into the cavity formed by the second half - mold 13, the filling opening 33 and the ventilation opening are automatically closed. This means that the filling syringe 10 does not have to have a closing mechanism for closing the filling opening 33.

[0189] Since both half - molds 12, 13 define the cavity 14 and at the same time form a capacitor plate, the distance between the "capacitor plate" and the cavity 14 is very small. As a result, the loss of electromagnetic radiation is very low, which means that the proportion of the power introduced as heat into the foam particles 29 to be fused is very high. Therefore, such a tool allows the foam particles 29 to be fused very effectively to form a particulate foam part.

[0190] Figure 8 An apparatus 1 for manufacturing a particulate foam part according to another embodiment is shown, where, similar to Figure 7 , the second half - mold 13 is formed of a conductive material and is connected to the ground potential 30, thus serving as the second capacitor plate.

[0191] The first half - mold 12 is non - conductive and, as in the type shown in Figure 7 , includes a boundary wall 34, which is shaped and fixedly connected to a cover element 37 by a partition 35. Here, again, a cavity 36 is formed between the partitions 35 to affect the electromagnetic field in the cavity 14 between the two half - molds 12, 13, as explained in detail above.

[0192] Similar to Figure 7Contrary to the embodiment shown, the circumferential side wall 32 that encloses the cavity 14 laterally is formed on the first half - mold 12. Inside the side wall 32, a part 38 of the conductive second half - mold 13 extends into the cavity 14 formed by the circumferential side wall and encloses the cavity 14 laterally, while on the opposite side it is enclosed by the boundary wall 34 of the first half - mold 12.

[0193] When the two half - molds 12, 13 are pressed together by means of a press 73 against the first half - mold 12 by the segmented capacitor plates 15 being pressed, the foam particles 29 located in the cavity 14 are pressed by the protrusions 38.

[0194] The filling opening 33 for filling the foam particles 29 leads to the cavity 14, is opened by separating the two half - molds 12, 13, and is closed by moving the two half - molds 12, 13 towards each other, as described above, including further details with reference to Figure 7 of.

[0195] Figure 9 Another embodiment of the present invention is shown, in which the sections of the capacitor plates are electrically insulated from each other.

[0196] In the device 1 shown here, the sections 85 of the first capacitor plate 15 formed by them are permanently attached to the insulator 80, electrically insulated from each other, and each section is connected to the generator 18 individually via an adjustable resonant circuit 40. The generator 18 is connected to the ground potential 30.

[0197] The sections 86 forming the second capacitor plate 16 are electrically connected to the ground 30, and so is the generator 18. The sections 86 are permanently attached to the insulator 81. If, as is the case here, all the sections 86 are connected to the ground, it is not absolutely necessary to arrange the sections 86 electrically isolated from each other. It is also possible to make the second capacitor plate 16 continuous or non - segmented or divided into multiple sections and electrically connect it to the ground 30.

[0198] In the case where the sections 86 of the second capacitor plate 16 are electrically isolated from each other, the generator 18 can be connected to each section 86 instead of the ground 30, in which case the sections 86 are not connected to the ground 30.

[0199] As referred to above Figure 2 stated, the insulator 80 is mechanically connected to the pressing tool formed by the press 73 and the cylinder - piston unit 76. This allows the insulator 80 and the sections 85 of the first capacitor plate 15 attached thereto to be pushed towards the second capacitor plate 16 located in the opposite position, so that pressure is applied from both sides to the molding tool 3 located between the two capacitor plates 15 and 16 for fusing the foam particles arranged therein.

[0200] The insulators 80, 81 and the sections 85, 86, together with the tunable resonant circuit 40, form a capacitor plate group 90. The sections 85, 86 are designed as capacitor plate sections and can be designed as in the above-described types and embodiments. They can also have geometries and form a two-dimensional arrangement as described above.

[0201] The molding tool 3 can be designed as one of the above-described types and embodiments. Minor modifications may be required to arrange the capacitor plates 15, 16 according to Figure 9 .

[0202] Figure 10 and 11 for explaining the operation of the device shown below in Figure 9 . Figure 10 A simplified equivalent circuit diagram of the device according to Figure 9 is schematically shown.

[0203] Figure 11 A single device for controlling the electric power supplied to the section pair 85, 86 is shown in a schematically simplified circuit diagram. In particular, Figure 11 a generator 18 and a partial capacitor formed by the sections 85, 86 enclosing the half-molds 12, 13, and a connecting line (hollow waveguide or coaxial line) 46 suitable for transmitting electromagnetic waves are schematically shown in a circuit diagram. The electromagnetic waves are transmitted from the generator 18 to the molded partial capacitors 85, 86 through this connecting line. The hollow waveguide forming the connecting line 46 is preferably designed as a coaxial air line having a conductive inner tube and a conductive outer tube. The dimensions of the coaxial air line are designed such that high-voltage signals can be reliably transmitted. The characteristic impedance is preferably set to approximately 50 Ω.

[0204] In this connecting line 46, a generator-side inductor 47 and a tool-side inductor 48 are symbolically shown. These inductors are caused by the line itself, whereby the length of each line section determines the value of each inductor. The tool-side capacitor 49 is connected in parallel with the corresponding tool sub-capacitors 85, 86. This capacitor 49 represents the capacitance between the capacitor section 85 and the housing 35 of the molding tool 3. The tool capacitors 85, 86, the capacitor 49, and the tool-side inductor 48 form a tool resonant circuit 50.

[0205] The capacitor 51 on the generator side is connected in series with the generator 18 and the inductor on the generator side. The capacitor 51 on the generator side and the inductor 47 on the generator side form a generator resonant circuit 52. At least the capacitor 51 on the generator side or the inductor 47 on the generator side is variably set, for example, by using a capacitor with separable capacitor plates or by providing connecting wire portions of different lengths. It is also possible that both the capacitor 51 on the generator side and the inductor 47 on the generator side are variable. The capacitor 51 on the generator side can be equipped with a servo motor, which, when actuated, changes the distance between the two capacitor plates, for example, by moving one of the two capacitor plates in a straight line so that the two capacitor plates are always parallel to each other, or by rotating one of the two capacitor plates.

[0206] By changing the capacitance of the capacitor 51 or the inductor 47, the resonant frequency of the generator resonant circuit 52 can be changed or tuned. If the resonant frequencies of the generator resonant circuit and the tool resonant circuit match, the maximum electric power is transferred from the generator 18 to the tool resonant circuit 50 and thus to the tool sub-capacitors (or partial capacitors) 85, 86. By changing the resonant frequency of the generator resonant circuit 52, the transfer of electric power can be controlled in a targeted manner, where the greater the difference in the resonant frequencies of the two resonant circuits 50, 52, the lower the transferred power. Therefore, the tuning of the generator resonant circuit 52 can be used to specifically adjust the electric power introduced into the cavity 14.

[0207] In this embodiment, the resonant frequency of the generator resonant circuit 52 is changed. It is also possible to change the resonant frequency of the tool resonant circuit 50. This has the same effect on power transfer. However, it is more difficult to provide a variable capacitor or a variable inductor on the tool side than on the generator side.

[0208] Therefore, the sections 85, 86 each form a tool capacitor or a tool sub-capacitor or a tool partial capacitor, which are individually connected to the generator 18 via their own adjustable resonant circuits 40. Therefore, the resonant circuit 40 includes the tool resonant circuit 50 and the generator resonant circuit 52. By tuning the two resonant circuits 50, 52, the tool capacitors 85, 86 can be separated from the generator 18 individually or in groups by changing the resonant frequency, so that no power or almost no power is transferred to them. In this way, by changing the resonant frequency of one (or both) of the two resonant circuits 50, 52, they can be switched on or off from the radiation emitting devices of the capacitor plate sections 85, 86.

[0209] The resonant circuit 40 thus forms a switching device 41 for connecting the capacitor plate section 85 to the capacitor plate 15 or disconnecting it therefrom, respectively, or for connecting the capacitor plate section 86 to the capacitor plate 16 or disconnecting it therefrom. The sections 85, 86 can be connected or disconnected individually or in groups as partial capacitors to form the capacitors 15, 16.

[0210] This means that the electromagnetic radiation source 18 is part of the generator resonant circuit 52, and any connecting line for guiding the electromagnetic wave forms a tool resonant circuit 50 together with the corresponding pair of sections 85, 86 forming the partial capacitor. By changing the inductance or capacitance, the tool resonant circuit 50 can be tuned in its resonant frequency and forms a tunable resonant circuit.

[0211] In other words, the regulating or control device for controlling the tunable resonant circuit can be designed such that the power supply from the generator resonant circuit to the tool resonant circuit is switched on or off or interrupted by its tuning, where (at least) one of the two resonant circuits is provided as a tunable resonant circuit. In this way, the sections in question are added to or removed from the capacitor plate formed by several such sections, which applies electromagnetic radiation to the molding tool during the fusing process.

[0212] By controlling the energy supply on the respective lines, it can be set and controlled which sections 85 of the capacitor plate 15 (and / or sections 86 of the capacitor plate 16) are operated, while which sections are not. By switching on and off the respective sections by means of resonant circuit tuning, the dimensions of the capacitor plates 15, 16 can be adapted to the dimensions of the molding tool 3 with respect to its radiation-emitting surface. This means that it is not necessary to mechanically remove or attach the individual sections 85, 86 to adapt the surfaces of the capacitor plates 15, 16 according to the molding tool 3. Nor is it necessary to mechanically interrupt or mechanically switch the connecting line 46 between the generator 18 and the individual sections 85, 86.

[0213] Regarding further details, we refer to the already mentioned publication DE 102016123214 A1, which describes the circuit for tuning in more detail.

[0214] Figure 12 A device for controlling the electrical power supplied to the tool capacitors 15, 16 is shown in a schematically simplified circuit diagram. The generator 18 is connected to the tool capacitors 15, 16. The measuring capacitor 53 is connected in parallel with the tool capacitors 15, 16. Its capacitance is a small fraction of the capacitance of the tool capacitors 15, 16. The measuring capacitor 53 is connected to a voltage measuring device (voltmeter) 55 via a coaxial line 54. Preferably, a diode 56 is connected in parallel with the measuring capacitor 53. The coaxial line 54 is connected in series with an inductor 58 for filtering high-frequency signals.

[0215] A measuring unit consisting of a measuring capacitor 53 and a diode 56 is separated from the tool capacitors 15, 16 by an isolation capacitor 59. The isolation capacitor has a high dielectric strength. The capacitance of the isolation capacitor 59 is smaller than the capacitance of the measuring capacitor 53, which means that the voltage drop across the isolation capacitor 59 is higher than the voltage drop across the measuring capacitor 53. The ratio of the capacitance of the isolation capacitor 59 to the capacitance of the measuring capacitor 53 is preferably 1:100 or 1:1,000 or 1:10,000. Thus, the voltage applied to the tool capacitors 15, 16 is reduced in the measuring unit 53, 56 such that the voltage is within the measuring range of the voltage measuring device 55 and can be reliably detected by the voltage measuring device.

[0216] In this circuit, a voltage drop occurs across the measuring capacitor 53, which corresponds to the voltage applied to the tool capacitors 15, 16, and this voltage drop is reduced according to the ratio of the capacitance of the measuring capacitor 53 to the capacitance of the isolation capacitor 59. By providing the diode 56, only an oscillation half-wave of a certain polarity is generated. The diode 56 thus forms a rectifier for the voltage occurring across the measuring capacitor 53. This measuring voltage is measured by the voltage measuring device 55 and converted into a measuring signal. The measuring signal is forwarded to the control device 57, which automatically controls the generator 18 to deliver a predetermined electrical power to generate a specific voltage across the tool capacitor or a specific measuring voltage across the measuring capacitor, which specific measuring voltage is a fraction of the voltage across the tool capacitor.

[0217] Figure 11 The device shown can also be arranged in such a way that, for several or all of the pairs of segments 85, 86, according to Figure 12 Devices are provided for controlling the electrical power supplied to the capacitors formed by the respective pairs of segments 85, 86. This allows the power of each respective pair of segments 85, 86 to be controlled individually and the effective size of the tool capacitor to be set without any moving parts. Since the actual power or voltage supplied to the respective pairs of segments 85, 86 can be measured in a closed control loop and can be adjusted individually for the individual pairs of segments 85, 86, calibration of the resonant circuits (generator resonant circuit, tool resonant circuit) is also not required.

[0218] The following refers to Figure 1 an example of a process for manufacturing particulate foam components, such as soles or mid-soles or parts thereof. The foam particles are filled into the cavity 14 of the molding tool 3. Adjacent to the cavity 14, two capacitor plates 15, 16 are arranged, which are electrically connected to a radiation source 18 for electromagnetic radiation and generate electromagnetic radiation.

[0219] The capacitor plates 15, 16 or at least one of them are formed by several sections 85, 86. By combining an appropriate number of radiation - generating sections 85 and / or 86, the area of the capacitor plates 15, 16 is adapted to the dimensions of the molding tool 3.

[0220] The foam particles are fused together by electromagnetic radiation between the capacitor plates 15, 16. The foam particles are fused together by electromagnetic radiation between the capacitor plates 15, 16. The foam particles are heated by electromagnetic radiation in the molding tool 3, that is, heat is supplied to the foam particles by electromagnetic RF radiation. This fuses them together to form a particulate foam part.

[0221] Then, the obtained particulate foam part is demolded and removed from the molding tool.

[0222] According to a preferred embodiment, the sections 85, 86 are detachably electrically and mechanically connected to combine them. In a variant as Figure 9 shown, the sections 85, 86 are arranged to be electrically insulated from each other. By tuning the resonant circuits 40 connected to the respective sections, in the capacitor plates 15, 16, the sections 85, 86 are switched on or activated, or switched off or deactivated. In this way, they are combined with each other according to the dimensions and geometry of the molding tool 3.

[0223] This allows the surfaces of the capacitor plates 15, 16 that emit electromagnetic radiation to be adapted to different molding tools 3. As a result, when the molding tool 3 is replaced, it is not necessary to mechanically remove or mechanically add sections 85, 86. There is no need for mechanical separation or connection of the sections from the radiation source 18 to adapt the surface of the capacitor plates to the molding tool 3. This means that different molding tools 3 (for example, corresponding to different sole or midsole sizes, or corresponding to different sole or midsole configurations) can be irradiated electromagnetically one after another in a very short period of time.

[0224] To carry out the process, for example, one of the devices is used as Figures 1 - 11 shown in different models and embodiments, or one of the devices is used as discussed elsewhere in this disclosure. Moreover, the capacitor plate set 90 as described above can be used to carry out the manufacturing process.

[0225] Figure 13a -f shows a part of the device 1 with the capacitor plate 16, which includes several sections 86 having an adaptable distance d from the cavity 14, and the corresponding measurement results obtained from multiple tests run on such a device 1.

[0226] The overall construction of device 1 can be a design that is the same as or similar to any of the other devices discussed so far herein (in particular, embodiments of device 1). Thus, all of the options, embodiments, modifications, and features that have been discussed can also be used in or in combination with device 1, which will now be described with respect to Figure 13a -f (provided, of course, that it is physically and technically possible). The compatibility between the different disclosed aspects and embodiments is also evidenced by the fact that the same reference numerals as above will also be used for elements and components that are functionally the same or at least functionally similar or equivalent.

[0227] The disclosed device 1 can be used, in particular, for manufacturing particulate foam components, especially soles or parts of soles (e.g., midsoles or parts thereof). It includes a molding tool 3 formed by (at least two) half - molds 12 and 13. The molding tool 3 defines a cavity 14 bounded by the two half - molds 12 and 13 (in particular Figure 13a ). Particles 29 of a foaming or expanding material (e.g., eTPU particles, or one of the other materials mentioned herein in this regard) are loaded into the cavity 14 and then fused or joined together (primarily on their surfaces, to maintain the internal foam structure, see Figure 13d ) to form a molded part.

[0228] The device also includes (at least two) capacitor plates 15 and 16, which are arranged adjacent to the cavity 14. Here, "adjacent" means that the two capacitor plates 15 and 16 are arranged on their two opposite sides and include the cavity 14 therebetween, such that the electromagnetic radiation emitted by the capacitor plates 15 and 16 fills the cavity 14 and causes the desired fusion of the foam particles 29.

[0229] One of the capacitor plates (here, the first capacitor plate 15) is connected to a radiation source (not shown). The other capacitor plate, here the second capacitor plate 16, includes several segments 86 having an adaptable distance d from the cavity 14, i.e., their positions along the z - direction (as Figure 13a and 13d shown) can be changed such that the radiation - emitting surface of each segment 86 is at a different distance d from the cavity (e.g., measured relative to the wall of the cavity 14 or a specific reference point within the cavity 14). Thus, the distance between the two capacitor plates 15 and 16 is also locally changed by adjusting the positions of the segments 86. The distance d of the segments 86 from the cavity 14 can be adjusted individually by mechanical and / or electro - actuator means (e.g., by hand, or by a wrench, or by an electric motor or a linear actuator, or by a gear driven by an electric motor, depending on the specific design of the segments 86).

[0230] For one of the segments, as Figure 13aAs shown by section 86a in the figure, the distance to the cavity 14 is denoted as d, and the distance to the opposite capacitor plate 15 is denoted as D. If the position of section 86a changes in the z direction, both of these values change.

[0231] Section 86 is electrically connected to the conductive electrode body 100, which in the embodiments shown and discussed here is at ground potential and provided as a metal block. However, in other cases, it could alternatively be connected to the radiation generator, and the opposite capacitor plate could be grounded. Aluminum is an option as it has a relatively low weight and can be easily processed.

[0232] In Figure 13a -f, the section 86 is provided as a screw (e.g., a pin is also possible) that is adjustably connected to the electrode body 100. Here, the screw 86 is a metal screw that is screwed into a corresponding thread provided in the electrode body 100.

[0233] Although in Figure 13a -f all the screws 86 are of the same type and size and have the same head size, this is not a rule, and the type, length, thickness, and head size of the screws 86 can also vary on the electrode / capacitor plate 16. For example, smaller screws or screw heads can be used in areas with more screws per unit area, i.e., in areas of the electrode / capacitor plate 16 where the density of section 86 is higher (not shown in the figure; in Figure 13a -f, the density of the section / screw 86 is constant on the capacitor plate 16 except at the edges of the plate).

[0234] The section / screw 86 is arranged in a two-dimensional grid, i.e., Figure 13a a square grid in the embodiment of Figure 13b and 13c -f. This grid is represented by the dashed line 130 in Figure 13a and

[0235] To allow the screw 86 to be fully screwed into the electrode body 100 without hitting the underlying floor (or components of device 1), the capacitor plate 16 with its electrode body 100 is mounted on four aluminum blocks 120 at its four corners, which raise it a certain distance from the floor and leave room for the screw 86 to protrude from the bottom side of the electrode body 100 when fully screwed in, i.e., when adjusted to its lowest position. The highest achievable position is when the screw 86 is almost fully unscrewed from the electrode body 100, but not completely. Usually, a small clearance is maintained to avoid an accidental detachment of one of the screws 86 from the electrode body 100 and / or an overall loss of stability when approaching the maximum height of the respective screw 86 above the electrode body 100.

[0236] A cover plate 110 of non-conductive material is arranged on the electrode body 100 (see Figure 13c ; in Figure 13b , the cover plate is removed to show the arrangement of the screws 86), and includes openings in which the screws 86 are arranged. This not only helps to stabilize them when the screws 86 are in an intermediate position or especially a high position, i.e., when screwed out to a greater extent from the electrode body 100. It also provides a stable and uniform support surface for adjacent components of device 1, especially the molding tool 3, to rest on (see Figure 13a 、 13c 、13d, 13e and 13f).

[0237] Such a cover plate 110 can generally be made of or include an electrically insulating cover. Preferably, the cover plate 110 is made of or contains one or more of the following materials: polytetrafluoroethylene (PTFE), polyethylene (PE), especially ultra-high molecular weight polyethylene (UHMWPE), polyetheretherketone (PEEK), thermoplastics, duroplast, polyethylene terephthalate (PET), polyoxymethylene (POM), polystyrene (PS), insulating mineral materials. In Figure 13e the case shown, it is made of PTFE.

[0238] An option is that each adjustable section / screw 86 can be set to at least one of the following four positions: removed (e.g., screwed out of the electrode body 100) or electrically disconnected, low position, intermediate position, high position. On the other hand, for example, for an adjustable section set as a screw 86, its position in the z-direction can also be continuously changed by screwing it in or out to the desired extent (of course, within the boundaries set by the lowest and highest positions). Having a limited number of predetermined positions to which the sections / screws 86 are set can facilitate the operation of device 1. In Figure 13a 、 13b, in FIGS. 13d, 13e and 13f, exemplary screws set to the low, middle and high positions are respectively denoted by reference numerals 86l (for low), 86m (for middle) and 86h (for high). In Figure 13d , as shown by the dashed ellipse 86x, one of the screws has been completely removed (alternatively, it can be electrically isolated from the capacitor plate 16 / ground potential).

[0239] When irradiated with electromagnetic radiation or filled with the cavity 14, the position of the section / screw 86 can be adjusted. However, generally, an automated start / regulation mechanism (as described above) may have to be employed for this purpose, because during the operation of the device 1, manual adjustment is usually not allowed or possible to avoid injury.

[0240] As described and explained above, adjusting the position of one or more sections / screws 86 affects the field strength distribution of the radiated electromagnetic field within the cavity 14. For example, in Figure 13d , four regions or positions p1, p2, p3 and p4 are schematically shown within the cavity 14. These regions have screws 86 at different positions / heights set below them. For example, position p1 has a screw between the middle and low positions set directly below it, position p2 has no screw below it at all (since the screw at position 86x has been removed), position p3 again has a screw between the middle and low positions set directly below it, and position p4 has a screw between the middle and high positions set directly below it. In this way, the electric field intensity distribution as well as the temperature and fusion conditions can be adjusted and controlled at different positions from p1 to p4.

[0241] Figure 13e and 13f The experimental results shown in Figure 13e -f provide further understanding in this regard. On the left-hand side of the two figures, different configurations of the device 1 are schematically shown, which are used to study the heating rate and temperature at different positions of the screw 86 in the capacitor plate 16 within the molding tool 3. In each of the three cases studied, two reference positions within the molding tool are considered, denoted as p1 and p2, p3 and p4, and p5 and p6 in Figure 13e -f, one at the front of the tool (p1, p3 and p5 respectively) and one at the rear of the tool (p2, p4 and p6 respectively). Using a constant setting of the radiation generator (not shown) and different settings of the screw 86 as shown on the left-hand side of Figure 13e -f, the variation of the heating rate / temperature with time at positions P1 - P6 is recorded, resulting in the measurement curves C1 - C6 shown on the right-hand side of Figure 13e -f.

[0242] Figure 13eThe x-axis in the measurement curve on the right side of -f shows time (the distance between two adjacent scales or grid lines on the x-axis corresponds to Figure 13e and 13f about 43 seconds in), and the y-axis shows temperature (in the range of 20 °C to 140 °C in Figure 13e and in the range of 20 °C to 160 °C in Figure 13f ).

[0243] In the case where all the screws shown in Figure 13e are set above the middle / mid position 86m, the measurements at positions P1 and P2 respectively produce measurement curves C1 and C2.

[0244] In the case where all the screws shown in Figure 13e are set below the low position 86l, the measurements at positions P3 and P4 respectively produce measurement curves C3 and C4.

[0245] In the case shown in Figure 13f , the screws in the front half of the tool are set to the middle position 86m, the screws in the rear half of the tool are set to the low position 86l, and the measurements at positions P5 and P6 respectively produce measurement curves C5 and C6.

[0246] As can be inferred from the results, setting the position of the screw 86 corresponding to a given measurement position to the middle position 86m results in a greater heating rate (i.e., a greater increase in temperature per unit time = the slope of the corresponding measurement curve) and a greater maximum temperature compared to setting the screw 86 to the low position 86l. Further setting one or more screws 86 to the high position, or completely removing one or more screws 86, will further change the heating rate / maximum temperature according to this principle (for example, with a constant setting of a given energy source, the higher the screw position in the z-direction, the greater the heating rate and the maximum temperature).

[0247] In the case of the highest temperature reached in the experiments shown and discussed regarding Figure 13e , i.e., approximately 135 °C at positions P1 and P2 (see curves C1 and C2) and approximately 115 °C at positions P3 and P4 (see curves C3 and C4), and in the case of the highest temperature reached in the experiments shown and discussed regarding Figure 13f , i.e., approximately 145 °C at position P5 (see curve C5) and approximately 125 °C at position P6 (see curve C6), are all customized according to the specific material used for these experiments, i.e., the granules 29 of expanded thermoplastic polyurethane (eTPU). In other words, the temperatures reached are set to fall within the processing window of this specific material.

[0248] When using particles 29 made of or comprising different kinds of materials, it is generally necessary to adjust the maximum temperature value to specific processing characteristics and the available processing window of the materials used. Generally, the maximum temperature for processing any of the materials mentioned herein will not exceed 270 °C. For example, by increasing the applied voltage, the achieved maximum temperature value will generally also increase. Changing the frequency of the applied electromagnetic field, for example from 27.12 MHz to 54.20 MHz, will also result in a change in the maximum temperature reached (and will generally also result in a change in, for example, the heating rate). As described and discussed above, adjusting the section / screw 86 to a higher position (i.e., a smaller d value) will also result in an increase in the (maximum) temperature at the corresponding position / area within the cavity 14, and thus these factors are interrelated and must be balanced against each other, as understood by a person skilled in the art.

[0249] Moreover, materials with a higher dielectric loss factor will generally heat up faster and more strongly, and thus this also needs to be taken into account when exchanging materials and adjusting, for example, the voltage, frequency, and / or position of the section / screw 86 and the duration of the manufacturing process.

[0250] In addition to the above-mentioned possibilities of adjusting the field distribution within the cavity 14, the shape of the other capacitor plate (i.e., here the capacitor plate 15 connected to the radiation source) can also be at least partially adapted to the geometry of the part to be manufactured (i.e., the sole or a part of the sole, such as the midsole or a part thereof). Thus, this “conventional and static” method for adjusting the field distribution can supplement the “dynamic” adjustment possibilities provided by the section 86 with an adjustable distance d to the cavity 14 disclosed herein.

[0251] The fifth aspect of the present invention is related to the fourth aspect and can also utilize or rely on any options, embodiments, and examples disclosed in the context of the first, second, and / or third aspects of the present invention, and is a method for manufacturing a sole or a part of a sole from foam particles 29.

[0252] In one embodiment, the method comprises: a.) loading the particles 29 into the cavity 14 of a molding tool 3, the molding tool 3 being formed by at least two half-molds 12, 13 defining the cavity 14, wherein at least two capacitor plates 15, 16 are arranged adjacent to the cavity 14, wherein at least one of the capacitor plates 15 is connected to a radiation source, and wherein at least one of the capacitor plates 16 comprises several sections 86 having an adaptable distance d to the cavity 14; b.) irradiating the cavity 14 with electromagnetic radiation emitted by the capacitor plates 15 and 16; and c.) locally adjusting the field strength distribution of the irradiated electromagnetic field within the cavity 14 by changing the adaptable distance d of the sections 86 to the cavity 14.

[0253] The change can occur before and / or during the irradiation of the cavity 14 with electromagnetic radiation.

[0254] The foam particles 29 can comprise or consist of one or more of the following base materials: thermoplastic polyurethane (TPU), polylactide (PLA), polyamide (PA), polyether block amide (PEBA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and / or thermoplastic polyester ether elastomer (TPEE). As previously mentioned, these foam particles are particles containing so-called bead foams, also known as pellet / particle foams in the art. Generally, the foam obtained from the use of connected foam particles is in the form of beads of the polymer foam component denoted by the name "e", for example, eTPU.

[0255] In summary, from the above discussion of the possible different options, modifications, and embodiments within the scope of the present disclosure of the device 1 with respect to Figure 13a -f, the person skilled in the art understands how these options, modifications, and embodiments translate into the corresponding steps of a method for operating such a device 1 to manufacture a particulate foam component, in particular a sole or part of a sole, from the foam particles 29. To avoid unnecessary repetition, reference is therefore made to the above explanation.

[0256] List of reference signs

[0257] 1 Device

[0258] 2 Material container

[0259] 3 Molding tool

[0260] 4 Delivery line

[0261] 5 Base

[0262] 6 Compressed air line

[0263] 7 Compressed air source

[0264] 8 Propulsion nozzle

[0265] 9 Compressed air line

[0266] 10 Filling syringe

[0267] 11 Compressed air line

[0268] 12 Half mold

[0269] 13 Half mold

[0270] 14 Cavity

[0271] 15 First capacitor plate

[0272] 16 Second capacitor plate

[0273] 17 Electrical connection wire

[0274] 18 Generator / AC voltage source

[0275] 19 Limiting surface of half - mold (inner side)

[0276] 20 Fan

[0277] 21 Outer surface of half - mold

[0278] 24 Substrate

[0279] 28 Insulating coating

[0280] 29 Foam particles

[0281] 30 Ground potential

[0282] 31 Base wall

[0283] 32 Circumferential side wall

[0284] 33 Filling opening

[0285] 34 Boundary wall

[0286] 35 Partition board

[0287] 36 Cavity

[0288] 37 Cover element

[0289] 38 Protruding part

[0290] 40 Resonant circuit

[0291] 41 Switching device

[0292] 46 Connection wire

[0293] 47 Generator - side inductor

[0294] 48 Tool - side inductor

[0295] 49 Tool - side capacitor

[0296] 50 Tool resonant circuit

[0297] 51 Generator - side capacitor

[0298] 52 Generator resonant circuit

[0299] 53 Measuring capacitor

[0300] 54 Coaxial cable

[0301] 55 Voltage measuring device

[0302] 56 Diode

[0303] 57 Control device

[0304] 58 Inductor

[0305] 59 Isolation capacitor

[0306] 73 Press

[0307] 76 Cylinder-piston unit

[0308] 80, 81 Insulator

[0309] 82 Screw

[0310] 83 Electrical connection element

[0311] 85, 86 Section / tool capacitor / screw

[0312] 86a Section / screw

[0313] Distance d to the cavity

[0314] Distance D to the opposite capacitor plate

[0315] 86h Section / screw at high position

[0316] 86m Section / screw at intermediate position

[0317] 86l Section / screw at low position

[0318] 86x Section / screw completely removed

[0319] 87 Generator connection section / first capacitor plate section

[0320] 88 Boundary section

[0321] 89 Central section

[0322] 90 Capacitor plate group

[0323] 91 Attachment section

[0324] 100 Electrode body

[0325] 110 Cover plate

[0326] 120 Bump

[0327] 130 Grid

[0328] p1-p4 Reference points

[0329] P1-P6 Measurement positions / areas

[0330] C1-C6 Measurement curves

[0331] Further embodiments are described below to facilitate understanding of the present invention:

[0332] 1. An apparatus for manufacturing a particulate foam component, in particular a sole or midsole or a part thereof, the apparatus comprising:

[0333] A molding tool (3) defining a cavity (14), wherein at least two capacitor plates (15, 16) are arranged adjacent to the cavity (14), wherein the capacitor plates are connected to a radiation source (18) for electromagnetic radiation, wherein the radiation source (18) for electromagnetic radiation is designed to emit electromagnetic radiation, and the molding tool (3) is formed by at least two half - molds (12, 13),

[0334] wherein at least one of the two capacitor plates (15, 16) is formed by several sections (85, 86) such that the surface of the capacitor plate (15, 16) can be adapted to the size of the molding tool (3).

[0335] 2. The apparatus according to example 1, wherein the sections (85, 86) of one or both capacitor plates (15, 16) are detachably electrically and mechanically connected to each other.

[0336] 3. The apparatus according to example 1 or 2, comprising a conductive connecting element (83) that electrically connects two or more sections (85, 86) to each other at their edges.

[0337] 4. The apparatus according to any one of the preceding examples, wherein the sections (85, 86) have portions (88) at their edges that interlock when the sections (85, 86) are joined together.

[0338] 5. The apparatus according to any one of the preceding examples, wherein the sections (85, 86) are detachably attached to insulators (80, 81).

[0339] 6. The apparatus according to any one of the preceding examples, wherein at least one section (87) of one or both capacitor plates (15, 16) formed by the sections (85, 86) is electrically connected to the radiation source (18).

[0340] 7. The apparatus according to example 1, wherein the sections (85, 86) of one or both capacitor plates (15, 16) are permanently attached to insulators (80, 81) and can be individually switched on or off to adjust the size of the capacitor plates (15, 16).

[0341] 8. The device according to Example 7, wherein the individual sections (85, 86) are electrically insulated from each other and each section is connected to the radiation source (18) via a high-frequency line (17) respectively.

[0342] 9. The device according to Example 7 or 8, wherein the sections (85, 86) are each connected to a resonant circuit (40) comprising two resonant circuits (50, 52), at least one of the two resonant circuits (50, 52) being tunable such that the radiation supply can be adjusted by tuning the tunable resonant circuit.

[0343] 10. The device according to any one of the preceding examples, wherein the sections (85, 86) together form shaped capacitor plates (15, 16).

[0344] 11. The device according to any one of the preceding examples, wherein the sections (85, 86) are arranged only on one side of the cavity (14) and form capacitor plates (15, 16) at said side, and / or the half - mold is conductive and serves as a capacitor plate.

[0345] 12. The device according to any one of the preceding examples, wherein at least one of the capacitor plates (15) formed by the sections (85, 86) is electrically connected to the radiation source (18), while the other capacitor plate (15) or its section (86) is electrically grounded.

[0346] 13. The device according to any one of the preceding examples, wherein the sections (85, 86) each have a geometry which, when the sections (85, 86) are combined, results in capacitor plates (15, 16) whose geometry is adapted to the geometry of the molding tool (3).

[0347] 14. A capacitor plate set for a device for manufacturing a particulate foam component, in particular for manufacturing a sole or midsole or a part thereof, the capacitor plate set comprising:

[0348] at least a first capacitor plate section (87) which is adapted to be attached to an insulator and comprises a terminal portion adapted to be connected to a radiation source (18) for generating electromagnetic radiation; and

[0349] one or more second capacitor plate sections (85);

[0350] wherein the first capacitor plate section (87) and the second capacitor plate section (85) are designed to together form a capacitor plate (15) whose surface area can be adapted to the dimensions of a molding tool (3) for manufacturing a particulate foam component.

[0351] 15. The capacitor plate group according to Example 14, wherein the one or more capacitor plate sections (85, 86) are detachably electrically and mechanically connected to each other to jointly form the capacitor plates (15, 16).

[0352] 16. The capacitor plate group according to Example 14, wherein each of the one or more second capacitor plate sections (85) includes a terminal area for connection to a radiation source (18) to generate electromagnetic radiation, and each capacitor plate section (85, 87) is designed such that it is electrically insulated from other capacitor plate sections (85, 87) in the capacitor plate (15) formed thereby and can be switched on or off through an adjustable resonant circuit (40).

[0353] 17. The capacitor plate group according to any one of Examples 14 to 16, wherein the capacitor plate group is adapted to be used in the device according to any one of Examples 1 to 13.

[0354] 18. A method of manufacturing a particulate foam component, in particular a sole or midsole or a part thereof, comprising the steps of:

[0355] a. filling foam particles (29) into a cavity (14) of a molding tool (3), wherein at least two capacitor plates (15, 16) are arranged adjacent to the cavity (14) and are electrically connected to a radiation source (18) for electromagnetic radiation to generate electromagnetic radiation;

[0356] b. fusing the foam particles (29) by electromagnetic radiation between the capacitor plates (15, 16); and

[0357] c. demolding the particulate foam component; wherein

[0358] d. at least one of the two capacitor plates (15, 16) is formed by a plurality of sections (85, 86), and the area of the capacitor plates (15, 16) is adapted to the size of the molding tool (3) by combining the radiation generating sections (85, 86).

[0359] 19. The method according to Example 18, wherein the sections (85, 86) are detachably electrically and mechanically connected to each other to combine them.

[0360] 20. The method according to Example 18, wherein the sections (85, 86) are arranged to be electrically insulated from each other and are switched on and off by tuning a resonant circuit (40) connected to the sections (85, 86) to combine them with each other.

[0361] 21. The method according to example 20, wherein the voltage applied to the individual pairs of sections (85, 86) is measured separately, and the power supplied to the respective pair of sections (85, 86) is adjusted separately based on the measured voltage.

[0362] 22. The method according to any one of examples 18 to 20, wherein the device according to any one of examples 1 to 14 and / or the capacitor plate group according to any one of examples 15 to 17 is used.

Claims

1. An apparatus for manufacturing a particulate foam component, in particular a sole or midsole or a part thereof, the apparatus comprising: A molding tool (3) formed by at least two half - molds (12, 13) and defining a cavity (14), wherein at least two capacitor plates (15, 16) are arranged adjacent to the cavity (14), wherein the capacitor plates are connected to a radiation source (18) for electromagnetic radiation, and wherein the radiation source (18) for electromagnetic radiation is designed to emit electromagnetic radiation. Wherein at least one of the two capacitor plates (15, 16) is formed by several sections (85, 86) such that the shape and size of the surface of the capacitor plate (15, 16) can be adapted to the shape of the component to be manufactured in the molding tool (3).

2. The device according to claim 1, wherein The sections (85, 86) of one or both capacitor plates (15, 16) are detachably electrically and mechanically connected to each other.

3. The apparatus according to claim 1 or 2, comprising a conductive connecting element (83) that electrically connects two or more sections (85, 86) to each other at their edges.

4. The device according to claim 1 or 2, wherein The sections (85, 86) have parts (88) at their edges that interlock when the sections (85, 86) are joined together.

5. The device according to any one of the preceding claims, wherein, The sections (85, 86) are detachably attached to insulators (80, 81).

6. The apparatus according to any one of the preceding claims, wherein, At least one section (87) of one or both capacitor plates (15, 16) formed by the sections (85, 86) is electrically connected to the radiation source (18).

7. The apparatus according to claim 1, wherein, The sections (85, 86) of one or both capacitor plates (15, 16) are permanently attached to insulators (80, 81) and can be individually switched on or off to adjust the size of the capacitor plates (15, 16).

8. The apparatus according to claim 7, wherein The individual sections (85, 86) are electrically insulated from each other, and each section is separately connected to the radiation source (18) via a high - frequency line (17).

9. The device according to claim 7 or 8, wherein The sections (85, 86) are each connected to a resonant circuit (40) comprising two resonant circuits (50, 52), at least one of the two resonant circuits (50, 52) being tunable such that the radiation supply can be adjusted by tuning the tunable resonant circuit.

10. The device according to any one of the preceding claims, wherein, The sections (85, 86) together form a shaped capacitor plate (15, 16).

11. The apparatus according to any one of the preceding claims, wherein, The sections (85, 86) are arranged only on one side of the cavity (14) and form the capacitor plates (15, 16) at that side, and / or the half - molds are conductive and serve as capacitor plates.

12. The apparatus according to any one of the preceding claims, wherein, At least one (15) of the capacitor plates formed by the sections (85, 86) is electrically connected to the radiation source (18), while the other capacitor plate (16) or its section (86) is electrically grounded.

13. The device according to any one of the preceding claims, wherein, The sections (85, 86) each have a geometry that, when the sections (85, 86) are combined, results in a capacitor plate (15, 16) whose geometry is adapted to the geometry of the molding tool (3).

14. A method of manufacturing a particulate foam component, in particular a sole or midsole or a part thereof, comprising the steps of: a. filling foam particles (29) into a cavity (14) of a molding tool (3), wherein at least two capacitor plates (15, 16) are arranged adjacent to the cavity (14) and are electrically connected to a radiation source (18) for electromagnetic radiation to generate electromagnetic radiation; b. fusing the foam particles (29) by electromagnetic radiation between the capacitor plates (15, 16); and c. demolding the particulate foam component; wherein d. at least one of the two capacitor plates (15, 16) is formed by a plurality of segments (85, 86), wherein the area of the capacitor plates (15, 16) is adapted to the size of the molding tool (3) by combining the radiation generating segments (85, 86).

15. The method according to claim 14, wherein, The segments (85, 86) are detachably electrically and mechanically connected to each other to combine them.

16. The method according to claim 14, wherein, The segments (85, 86) are arranged electrically insulated from each other and are switched on and off by tuning a resonant circuit (40) connected to the segments (85, 86) to combine them with each other.

17. The method according to claim 16, wherein, The voltage applied to individual pairs of segments (85, 86) is measured individually, and the power supplied to the respective pair of segments (85, 86) is adjusted individually according to the measured voltage.

18. The method according to any one of claims 14 to 17, wherein Use of a device according to any one of claims 1 to 13.

Images