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

Abstract

The invention relates to a device and a method for manufacturing a sole or a part of a sole from foam particles. A device for manufacturing a sole or a part of a sole from foam particles is disclosed, wherein the device comprises: a.) a molding tool formed by at least two mold halves, which defines a mold cavity, and b.) at least two capacitor plates, which are arranged adjacent to the mold cavity, wherein c.) at least one capacitor plate is connected to a radiation source, and wherein d.) at least one capacitor plate comprises several sections at an adaptable distance from the mold cavity. A method of using such a device in manufacturing a sole or a part of a sole from foam particles is also disclosed.

Description

Technical Field

[0001] The invention relates to a device, a method and a capacitor plate assembly for producing a particle foam component.

[0002] The present invention provides a device, method and capacitor plate group for manufacturing particle foam using electromagnetic waves, wherein foam particles are fused (welded) into particle foam components by electromagnetic waves, and the energy required for fusion is applied to the foam particles by electromagnetic waves.

[0003] The device, method and capacitor plate set can be used in particular for manufacturing a sole or a part of a sole, in particular a midsole or a part of a sole. The invention also relates to a sole or a part of a sole, in particular a midsole or a part of a midsole manufactured in this way. Background Art

[0004] A method for sintering moist thermoplastic foam particles is described in US Pat. No. 3,079,723. The particles are dielectrically heated and compressed at the same time. Electromagnetic waves with a frequency of about 2 to 1000 MHz are applied.

[0005] Document US Pat. No. 3,242,238 describes a similar process. In this method, foam particles are moistened with an aqueous solution and exposed to an electromagnetic field with a frequency of about 5 to 100 MHz.

[0006] Document GB 1,403,326 describes a method for fusing expandable polystyrene foam particles. In this method, the particles are moistened with an aqueous solution and exposed to an electromagnetic field ranging from 5 to 2000 MHz.

[0007] WO 01 / 064414 A1 discloses a method in which polyolefin polymer particles moistened with a liquid medium are heated by electromagnetic waves, in particular microwaves. The temperature in the mold is controlled by controlling the pressure in the mold.

[0008] WO 2013 / 050181 A1 describes a method for producing a particle foam component, wherein a mixture of foam particles and a dielectric transfer liquid is heated by electromagnetic waves to fuse the foam particles into a particle foam component. Radio waves or microwaves are used as electromagnetic waves. The material of the foam particles is formed of polypropylene (PP).

[0009] Despite these considerable efforts, no machines for fusing foam particles by electromagnetic waves have been established in industrial manufacturing to date. One of the main reasons for this is that heat cannot be introduced uniformly into the foam particles and a uniform fusion cannot be produced within the particle foam part.

[0010] Therefore, in commercial applications, machines that fuse foam particles by using steam have been mainly used so far. However, these machines have the disadvantage of low energy input efficiency. In addition, the particle foam parts are still moist after fusion and cannot be further processed immediately. Since the heating is carried out from the outside inwards, the inner parts of the parts cannot always be fused with sufficient quality. In addition, the device for generating steam is much more expensive than the generator for electromagnetic waves.

[0011] The fusion of foam particles with electromagnetic radiation requires that high energy is provided to the foam particles, for which reason the foam particles are located in the molding tool. In addition, the energy input into the foam particles should be as uniform as possible to achieve uniform heating and therefore uniform fusion of the foam particles.

[0012] One problem is that the electrodes and the corresponding molding tools usually have different sizes. Depending on the product to be manufactured, the molding tool must be changed. Therefore, different molding tools are used in the fixture, which can be different in size. The molding tool is usually a little smaller than the electrode to completely contain the molding tool within the electric field of the flat plate capacitor. Therefore, the electrode usually protrudes a little to the side of the molding tool. This creates an unused electric field. The capacitance of the capacitor is greater than what is needed. As a result, the capacitor takes up more charge and therefore also more energy than is needed.

[0013] Another problem, especially with regard to the manufacture of soles or parts of soles, especially midsoles or parts thereof, is the complex three-dimensional geometry of these parts. For example, a sole almost never has a constant thickness along its longitudinal and / or medial to lateral extension. This complicates the fusion process, since it is difficult to achieve a constant and uniform fusion of the particles over all areas of the sole. Summary of the invention

[0014] The applicant of the present patent application has improved the known devices and methods for fusing foam particles by electromagnetic waves and the corresponding processes, in particular in the context of the manufacture of shoe soles. These devices and methods are based on the technology described in the publications DE 102016 100 690 A1 and DE 10 2016 123 214 A1 and German patent application No. 10 2019 127 680.2, as well as the published applications DE 10 2015 202 013 A1 and DE 10 2016 223980 A1 owned by the applicant of the present application, in conjunction with the present invention described below, in particular with regard to the devices, methods and materials, but not exclusively by reference to these documents.

[0015] The invention is based in particular on the problem of increasing the efficiency of the energy input and the problem of using the electric field more effectively in the production of particle foam parts, in particular soles / midsoles, by fusing foam particles by electromagnetic waves.

[0016] The invention is also based on the problem of improving the quality of soles or midsoles manufactured by fusing foam particles using an electromagnetic field, even if they have complex three-dimensional geometries, in particular varying thicknesses.

[0017] These issues are addressed and at least partially solved by different aspects of the present invention discussed in more detail below.

[0018] A first aspect of the invention provides an apparatus for producing a particle foam component, in particular a shoe sole or a part of a shoe sole (eg a midsole or a part thereof).

[0019] In one embodiment, the device includes a molding tool defining a cavity, wherein at least two capacitor plates are arranged adjacent to the cavity, which are connected to a radiation source for electromagnetic radiation, wherein the electromagnetic radiation source is suitable for emitting electromagnetic radiation, and the molding tool is formed by at least two half-molds, wherein at least one of the two capacitor plates is formed by several segments, so that the surface of the capacitor plate array with several segments can be adapted based on the shape of the product to be fused in the cavity.

[0020] For example, a capacitor plate formed from a plurality of 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 but also shaped electrodes can be used, such as for example for the manufacture of soles / midsoles.

[0021] For example, the segments are shaped in such a way that the shape and dimensions of its surface, in particular its lateral dimensions, can be adapted to the shape of the component to be manufactured in the molding tool by removing and / or adding individual segments to form the capacitor plate.

[0022] Preferably, the segments of the capacitor plate are detachably connected electrically and mechanically.In this way, individual segments can be removed or added to adapt the surface of the capacitor plate to the dimensions of the molding tool.

[0023] A conductive connecting element may be provided which electrically connects two or more segments at their edges. For example, a conductive metal element, such as a copper or brass foil, may be used, to which the edges of the segments of the electrode are clamped so that there is an electrical connection to all segments of the electrode.

[0024] Furthermore, the segments can have regions at their edges which interlock when the segments are joined together. This means that electrical and mechanical connections can be made particularly reliably and relatively cheaply at the segment joints. For this purpose, the edges or regions can be designed as stepped seams, for example.

[0025] On the other hand, the segments may also be provided in a non-interlocking manner, in particular without such interlocking areas, which may advantageously allow in-mold assembly, i.e. assembling the segments (or adding or removing one or more segments) without having to disassemble the molding tool / capacitor plate.

[0026] Preferably, the segments are removably attached to the insulator. The insulator serves to hold the segments in their position. The insulator is preferably suitable for high voltages and does not cause significant losses of RF radiation, otherwise it will heat up. Furthermore, the material used should not show a significant reaction to the electromagnetic field used in terms of its field permittivity and dielectric losses, as this would again lead to undesirable heating. Therefore, dielectric materials with a low dielectric loss factor as well as 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: aluminum oxide, aluminum nitride, aluminum silicate.

[0027] The segments of the electrodes 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 segments to the insulator.

[0028] For example, at least one segment of a capacitor plate formed by the segments is electrically connected to the radiation source.

[0029] According to one option, the segments of the capacitor plate can be permanently attached to the insulator and can be individually switched on or off to adjust the size of the capacitor plate. 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 the particle to radiation.

[0030] In this case, the segments are preferably electrically isolated from one another and each segment is individually connected to the radiation source, for example via a high-frequency line in the case where a high-frequency generator is used as the radiation source.

[0031] Advantageously, each segment is connected to a tunable resonant circuit and can be switched on or off, or activated or deactivated, individually or in groups by tuning the respective resonant circuit.

[0032] In particular, the segments may each form a partial capacitor which is connected to the tunable resonant circuit.

[0033] Each power supply line can be assigned a regulating capacitor, with which the energy provided by 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 segment(s) of the capacitor is operated. By switching the individual segments on and off by means of resonant circuit tuning, the size of the capacitor plates can be adapted to the size of the molding tool with respect to its radiation emitting surface. This means that it is not necessary to mechanically remove or attach the individual segments to the molding tool in order to adapt the surface of the capacitor plates.

[0034] Preferably, the segments together form a shaped capacitor plate.

[0035] In particular, the segments can be arranged on both sides of the cavity and, in particular, form segmented capacitor plates there.

[0036] These sections can also be arranged only on one side of the cavity and form segmented capacitor plates there. On the other side of the cavity, for example, a continuous capacitor plate can be arranged.

[0037] Furthermore, on the other side of the cavity, a conductive area of ​​the molding tool or a conductive mold half can be used as a capacitor plate opposite to the segmented capacitor plate. However, in the case of a contoured surface, a non-conductive mold half is preferred because it is easier to generate a uniform electric field. Furthermore, the use of a conductive mold half would carry the risk of burning the manufactured part in the area adjacent to the mold half, so non-conductive materials are also preferred from this perspective.

[0038] If both die halves were conductive, one die half would have to be connected to an RF radiating line, which would be relatively difficult or very expensive to achieve.

[0039] It is advantageous if at least one of the capacitor plates formed by the segments is electrically connected to the radiation source, while for example the other capacitor plate or a segment thereof is electrically connected to ground or earth.

[0040] In particular, the segments can each have a geometry which, when the segments are combined, produces a capacitor plate whose geometry, in particular its lateral extension, is adapted to the geometry and dimensions of the molding tool. For example, the segments can be rectangular, preferably of different sizes, so that rectangles of different sizes are formed as capacitor plates by combining several segments depending on the dimensions of the molding tool to be irradiated.

[0041] The edges of adjacent segments are advantageously parallel to one another in order to form a capacitor plate by combining several segments.

[0042] In particular, it is advantageous to arrange the individual segments in such a way that a central square segment is provided and the 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 further additional segments may be provided.

[0043] 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.

[0044] According to a second aspect of the invention, a capacitor plate set of an apparatus for producing a particle foam component, in particular a shoe sole or a part of a shoe sole (eg a midsole or a part thereof) is provided.

[0045] In one embodiment, the capacitor plate group includes at least one first capacitor plate segment adapted to be attached to an insulator and including a terminal area adapted to be connected to a radiation source to generate electromagnetic radiation, and one or more second capacitor plate segments, wherein the first capacitor plate segment and the second capacitor plate segment are adapted to jointly form a capacitor plate whose area is sized to be adapted to the size of a molding tool for manufacturing a particle foam component.

[0046] The capacitor plate segments form a set of several objects which together form at least one or several segmented capacitor plates, the dimensions of which are adapted to the dimensions of a molding tool used for fusing foam particles to produce a particle foam part.

[0047] Preferably, the capacitor plate segments are detachably electrically and mechanically connected.

[0048] In particular, the second capacitor plate segments may also each comprise a terminal region for connection to a radiation source for generating electromagnetic radiation.

[0049] Each capacitor plate segment may be designed such that it is electrically isolated from the other capacitor plate segments in the capacitor plate formed thereby and may be connected or disconnected from an energy source, for example via a tunable resonant circuit.

[0050] Preferably, the capacitor plate set is designed for use in a device according to one of the aspects of the invention.

[0051] A third aspect of the invention relates to a method for producing a particle foam component, in particular a shoe sole or a part of a shoe sole, for example a midsole or a part thereof.

[0052] In one embodiment, the method includes the following steps: a.) filling foam particles into a cavity of a molding tool, wherein at least two capacitor plates are arranged adjacent to the cavity, and the at least two capacitor plates are electrically connected to a radiation source for electromagnetic radiation to generate electromagnetic radiation; b.) fusing the foam particles by electromagnetic radiation between the capacitor plates; and c.) demolding; wherein d.) at least one of the two capacitor plates is formed by multiple 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.

[0053] The foam particles are heated in a molding tool so that they are fused to form a particle foam part. Heat is applied to the foam particles using electromagnetic RF radiation.

[0054] Advantageously, the segments are detachably electrically and mechanically connected to combine them.

[0055] According to one option, the segments can be arranged to be electrically isolated from each other and can be switched on or off to combine them, for example by tuning a resonant circuit connected to the respective segments. This allows the area of ​​the capacitor plate emitting radiation to be adjusted without having to mechanically remove or mechanically add segments. In particular, this eliminates the need to mechanically separate or connect the segments to the radiation source when adjusting the area of ​​the capacitor plate, which would require a lot of effort.

[0056] In particular, the segments can each form a partial capacitor.

[0057] It is advantageous to carry out the method using the device according to the invention and / or the capacitor plate group according to the invention.

[0058] The foam particles are preferably made of expanded thermoplastic material or contain 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 of different particles of different foam polymers or a combination thereof. Preferably, 90% by weight of the foam particles are composed of one or a mixture of these materials. These foam particles are particles containing so-called bead foams, also referred to in the art as pellets / particle foams. Typically, the foam obtained by using connected foam particles is represented by the name "e" to represent the bead form of the polymer foam component, such as eTPU.

[0059] The foam particles made of these materials are preferably heated primarily by direct absorption of the 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, direct absorption of RF radiation is very efficient and also allows the fusion of foam particles made of materials such as polyethylene terephthalate (PET), which has a softening temperature above 200° C. (typically around 260° C.), which is not possible with heating using aqueous heat transfer media. Furthermore, the use of such heat transfer agents can be avoided or reduced, thereby improving the quality of the final product.

[0060] However, within the scope of the invention, it is also possible to add a heat transfer medium.

[0061] 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 may be 300 MHz. Specific (center) frequencies that can be used and for which radiation sources are readily commercially available are, for example, 6.78 MHz, 13.56 MHz, 27.12 MHz, 40.68 MHz. However, even (center) frequencies of 2.45 GHz or 5.8 GHz may be used.

[0062] To generate electromagnetic RF radiation, the capacitor plates are preferably arranged on a molding tool which is otherwise made of an electrically insulating material. A high frequency voltage having 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.

[0063] At this voltage, powers in the range of 10 kW to 60 kW can be delivered to the foam particles in the mold cavity. This enables even large-volume particle foam parts and / or shoe soles or parts thereof to be reliably produced with very short cycle times of about 30 seconds to 2 minutes.

[0064] 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 caused by the thermal expansion of the foam particles during the fusion process, the foam particles are also compressed mechanically.

[0065] The molding tool is preferably made of a material that is substantially transparent (e.g. in the sense of a low relative dielectric constant) to the electromagnetic RF radiation used. Possible materials include polytetrafluoroethylene (PTFE), polyethylene (PE), especially ultra-high molecular weight polyethylene (UHMWPE), polyetherketone (PEEK). However, semi-permeable materials such as polyethylene terephthalate (PET), polyoxymethylene (POM) or polyketone (PK) can also be used.

[0066] The electromagnetic radiation source can be designed as part of a generator resonant circuit, where the segments can be connected or disconnected individually or in groups to form a capacitor. The line for guiding the electromagnetic waves forms a tool resonant circuit together with a pair of segments, each segment forming a partial capacitor. By varying the inductance or capacitance, the tool resonant circuit can be tuned and form a tunable resonant circuit, by which power transfer can be blocked or enabled in a targeted manner.

[0067] The control device for controlling the tunable resonant circuit can be designed so that power is supplied from the generator resonant circuit to the tool resonant circuit, which can be designed as a tunable resonant circuit, which can be switched on or enabled or interrupted by its tuning. In this way, the relevant segment is added to or removed from a capacitor plate formed by several segments, which applies electromagnetic radiation to the molding tool during the fusion process.

[0068] Depending on the size of the generator and the wiring connecting the generator resonant circuit to the tunable resonant circuit, the power delivered to the cavity via the tuned resonant circuit can be in the range of 25 kW to 60 kW.

[0069] 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 to the radiation source, either directly or through one or more sections thereof, whereby radiation is fed to the capacitor plate as an electromagnetic wave relative to the ground.

[0070] The fourth aspect of the invention can be combined with the above-mentioned first, second and / or third aspect of the invention and all possible options, modifications and embodiments thereof (if, of course, not physically or technically excluded), which is provided by a device for manufacturing a particle foam component, in particular a sole or a part of a sole (for example, a midsole or a part of a midsole).

[0071] In one embodiment, the device includes: a.) a molding tool formed by at least two mold halves, which defines a cavity; b.) at least two capacitor plates, which are arranged adjacent to the cavity; wherein c.) at least one capacitor plate is connected to a radiation source; and wherein d.) at least one capacitor plate includes several segments having an adaptable distance from the cavity.

[0072] We point out that the arrangement of the capacitor plates "adjacent" the cavity does not mean that the capacitor plates are in direct contact with the walls of the cavity or form the walls of the cavity. On the contrary, what this feature implies is that the capacitor plates are arranged "around" the cavity and at a distance from the cavity, which allows flooding or irradiation of the cavity with an alternating electromagnetic field suitable for producing the desired fusion of the foam particles in the cavity. Typically, for example, parts or portions of a molding tool (in particular, portions that are transparent or substantially transparent to the electromagnetic radiation used) will be arranged between the capacitor plates and the cavity (see, for example, the detailed discussion of possible embodiments with respect to the figures in the following sections), and the shape and size of the cavity are defined by the molding tool, rather than by the capacitor plates themselves (this makes it generally possible to use different molding tools with different cavities between the same set of capacitor plates).

[0073] In the disclosed device, a plurality of segments (hereinafter also referred to as "electrode elements") are designed in a manner that allows manual or automatic shape changes of the corresponding capacitor plates (hereinafter also referred to as "electrodes"). These shape changes are used to locally control the electric field strength within the cavity, and thus control the heating of the material in said location, as will be further explained in more detail below. This modularity brings manufacturing and product benefits.

[0074] Previous efforts in mold development have focused on complex electrode designs guided by precise simulations, with the goal of trying to match the electromagnetic field in the cavity to the desired value as closely as possible by directly designing the electrodes / capacitor plates. Since particle fusion by electromagnetic radiation (especially RF radiation) is based on dielectric heating of the target material, the uniformity of heating depends on a uniform electric field distribution at the operating frequency. This field is usually generated between (at least) two conductive electrodes / capacitor plates, one active and the other grounded, between which the insulating molding tool and the target part (here: the sole or a part of the sole) are located. Usually, the conductive metal electrodes / capacitor plates are partially shaped to adjust the field distribution to adapt to the interference caused by the molding tool and the molded part. If this shaping is not correct, multiple parts of the tool must be changed to optimize the electrode design. Moreover, the electrode shape cannot be changed during the process or between process cycles to adapt to changing product requirements or material changes.

[0075] In contrast, the disclosed device allows flexible changes to the tool settings, in particular with regard to the distance between the active and passive electrodes / capacitor plates, and in particular on the grid resolution. Depending on the selected actuation, the change can be manual or active. The change is fixed for the part currently being manufactured, or even changed during the process to allow more control than is currently available. For example, depending on the selected grid resolution, the field strength can be locally increased or decreased and thus the heating rate and maximum temperature experienced by the target set. This enables, for example, rapid adaptation to new mold geometries and locally adjusted part characteristics.

[0076] Thus, at least one electrode / capacitor plate is divided into a collection of elements or segments (e.g. a grid of such elements / segments) which can be moved parallel to the z-axis, which are placed in the direction from the electrode / capacitor plate towards the cavity, but which preferably always remain electrically connected to the body of the electrode (be it the active or passive side, preferably the passive side), which is then further connected to the radiation generator or to ground potential (preferably ground potential, as this allows a simpler construction). The distance between the electrode element / segment and the cavity and therefore the distance between the opposing electrode / capacitor plates affects the local field strength in the gap between the two electrodes / capacitor plates and therefore the local field strength within the cavity. This distance can be set by any form of actuator and the distance control can be performed at the level of the individual segments. In particular, it is possible to keep all elements always in electrical contact and not have the segment control system interfere with the electromagnetic fusion process.

[0077] For example, a set of experiments was conducted using an aluminum circuit board fixed with an array of screws. The screws were manually set to different heights. For the fusion of expanded thermoplastic polyurethane (eTPU) particles, significant differences in heating rates and maximum temperatures were achieved for different electrode configurations. The properties of the manufactured components also changed locally and accordingly.

[0078] In summary, by using the disclosed apparatus, improved prototype / component quality can be achieved and is well suited for product testing and / or prototype development. Thus, faster process development of new products can be achieved and lower cost tooling can be used. Changing the distance of the segment to the cavity, as well as the distance between the two electrodes / capacitor plates during the fusion process, can also allow new process optimization methods, thereby allowing product optimization.

[0079] Further details, options and embodiments of such an arrangement and some associated technical advantages are discussed below.

[0080] As already mentioned, the segments may be electrically connected to an electrically conductive electrode body. The electrode body may in particular be at ground potential.

[0081] In particular, a capacitor plate connected to a radiation source (e.g., a generator for RF radiation) may be a first capacitor plate on one side of the cavity, and a capacitor plate comprising several segments at an adaptable distance from the cavity may be a second capacitor plate on the opposite side of the cavity.

[0082] For example, as described at the beginning, an "active" capacitor plate connected to a radiation source and a "passive" capacitor plate containing an adjustable segment can be arranged on opposite sides of a cavity and enclose the cavity between them, and by effectively adjusting the distance of the segment to the cavity, the distance between the two capacitor plates is also locally changed. In the cavity, this leads to a change in the field intensity distribution of the electromagnetic field that fills the cavity and, therefore, to a change in the field intensity distribution at the surface of the particles that are fused under the influence of the electromagnetic field.

[0083] The distance of the segments to the cavity can be adjusted individually by mechanical and / or electrical actuator means.

[0084] In particular, the segments may be arranged in a two-dimensional grid, in particular a rectangular grid.

[0085] The grid density (i.e. the number of adjustable segments per unit area) can also be varied locally. For example, corresponding to the toe area and / or the heel area of ​​the sole to be manufactured, the segments 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 areas.

[0086] Alternatively or additionally, in order to change the density of the arrangement of the segments, their radiation-emitting surface area can also be locally changed. For example, screws or pins with different head sizes can be used (usually: the head size is smaller in the area of ​​the segments with higher density).

[0087] As just described, the segments may be arranged as screws or pins adjustably connected to the electrode body. The screws may for example be metal screws screwed into the electrode body, and the electrode body may also be made of or include metal, such as aluminum.

[0088] A cover sheet or covering layer of non-conductive material may further be arranged on the electrode body and include openings in which screws or pins are disposed.

[0089] Such a cover plate 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 are moved a long distance from the electrode body (for example, if the screws are unscrewed from the base plate 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 located. Without such a plate or layer, the adjustable position of the segments would result in a varying support surface for adjacent parts of the molding tool, which would not only require a more complex construction, but could also be detrimental to the stability of the tool.

[0090] Such a cover plate may be made of or include an electrically insulating cover. Preferably, the cover plate is made of or includes one or more of the following materials: polytetrafluoroethylene (PTFE), polyethylene (PE), in particular ultra-high molecular weight polyethylene (UHMWPE), polyetherketone (PEEK), thermoplastics, duroplasts, polyethylene terephthalate (PET), polyoxymethylene (POM), polystyrene (PS), insulating mineral materials.

[0091] One option is that each adjustable section can be set to one of at least four positions: removed or electrically disconnected, low position, middle position, high position.

[0092] For example, the adjustable section may be electrically disconnected by tuning a resonant circuit as disclosed herein with respect to other aspects of the invention and / or by simple switch-type elements.

[0093] In addition to being adjustable to predetermined positions, some or all of the segments may also be continuously adjustable in their position (ie, anywhere between a lowermost and uppermost position).

[0094] Having a limited set of predetermined positions may facilitate operation of the device, while having the possibility to continuously adapt the segment positions (in the z-direction, ie towards and away from the cavity) increases the amount of influence and control that can be exerted on the electromagnetic field intensity distribution.

[0095] When the cavity is irradiated or filled with electromagnetic radiation, the position of the segments can be adjusted. Again, by their "position", it is meant the position or height of the segments in the z-direction. In other words, changing the position of the segments changes their distance from the cavity.

[0096] As described and explained above, adjusting the position of one or more segments, ie their distance from the cavity and thus typically also from the opposing electrode / capacitor plate, influences the field strength distribution of the radiated electromagnetic field within the cavity.

[0097] Furthermore, the shape of the capacitor plates connected to the radiation source may also be at least partially adapted to the geometry of the part to be manufactured, ie the sole or a part of the sole, such as a midsole or a part thereof.

[0098] The fifth aspect of the invention is related to the fourth aspect and may 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 of manufacturing a sole or part of a sole from foam particles.

[0099] 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 segments having an adaptable distance from the cavity; b.) irradiating the cavity with electromagnetic radiation emitted by the capacitor plates; and c.) locally adjusting the field strength distribution of the irradiating electromagnetic field within the cavity by changing the adaptable distance of the segments to the cavity.

[0100] The alteration may occur before and / or during irradiation of the cavity with electromagnetic radiation.

[0101] The foam particles are preferably made of expanded thermoplastic material or contain expanded thermoplastic material, in particular thermoplastic polyurethane (TPU), polylactic acid ester (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 of different particles of different foam polymers or a combination thereof. Preferably, 90% by weight of the foam particles are composed of one or a mixture of these materials. These foam particles are particles containing so-called bead foams, also referred to in the art as pellets / particle foams. Typically, the foam obtained by using connected foam particles is represented by the name "e" as a bead form of the polymer foam component, such as eTPU.

[0102] It is mentioned that such foam particles are also referred to in the art as particles of expanded material, which is already foamed material (as opposed to expandable material which is foamable but 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

[0103] An example of how the invention can be implemented is explained in more detail below using the drawings. In addition, explicit reference is made to the publications DE 10 2016 100 690 A1 and DE 10 2016 123 214 A1 and German patent application No. 10 2019 127 680.2, as well as to the published applications DE 10 2015 202 013 A1 and DE 10 2016 223 980 A1, owned by the applicant of the present application, in which devices and methods further developed and improved by aspects of the present invention are described in detail.

[0104] The included drawings show the following:

[0105] Figure 1 An example of an apparatus for producing a particle foam component is schematically shown;

[0106] Figure 2 is a schematic diagram of an arrangement of segments forming two opposing capacitor plates for making a particle foam component;

[0107] Figure 3 The arrangement of interconnected sections is schematically shown in cross-section;

[0108] Figure 4 The arrangement of the segments which together form the capacitor plate is shown as a schematic diagram of the capacitor plate surface;

[0109] Figure 5-8 Different apparatuses for producing particle foam parts according to different embodiments of the present invention are shown;

[0110] Fig. 9 An arrangement for exposing a moulding tool to electromagnetic radiation according to another embodiment of the invention is shown in schematic form;

[0111] Fig.10 schematically shows an equivalent circuit diagram for an arrangement of segments, each segment being individually connected to a radiation source for generating electromagnetic radiation;

[0112] Fig.11 A switching device for connecting or disconnecting a capacitor plate segment to or from the capacitor plate for emitting electromagnetic radiation is shown;

[0113] Fig.12 A control device for controlling a power supply is shown in a circuit diagram; and

[0114] Fig.13a -f shows a part of a device with a capacitor plate comprising several sections at an adaptable distance from the cavity, and the corresponding measurement results obtained from a number of experiments run on such a device. DETAILED DESCRIPTION

[0115] Figure 1 A possible design of an apparatus 1 for producing a particle foam component, in particular a sole or midsole or a part of a sole / midsole is shown. The apparatus 1 comprises a material container 2, a molding tool 3 and a line 4 leading from the material container 2 to the molding tool 3.

[0116] The material container 2 is used to hold loose foam particles. The material container 2 has a base 5 and is connected to a compressed air source 7 in the base 5 via a compressed air line 6. The compressed air line 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, which air streams rotate the foam particles contained therein around them and thus separate them.

[0117] In the region of the base 5 of the material container 2 an opening is formed, to which the conveying line 4 is connected. The opening can be closed by means of a slide valve (not shown).

[0118] Adjacent to the material container 5 is a propulsion nozzle 8 in the conveying line 4, which is connected to the compressed air source 7 via another compressed air line 9. The compressed air supplied to this propulsion nozzle 8 serves as conveying air, since it enters the conveying line 4 through the propulsion nozzle 8 and flows in the direction of the molding tool 3. This generates 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.

[0119] The delivery line 4 leads to a filling syringe 10 connected to the molding tool 3. The filling syringe 10 is connected to the compressed air source 7 via a further 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 particle flow 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 particles from the delivery line 4 back into the material container 2 when the filling process at the molding tool 3 is completed.

[0120] The molding tool 3 is formed by two mold halves 12, 13. At least one cavity 14 is defined between the two mold halves 12, 13, into which the filling syringe 10 is passed to introduce the foam particles. By bringing the two mold halves 12, 13 together, the volume of the cavity 14 can be reduced. When the mold halves 12, 13 are moved apart from each other, a gap is formed between the mold halves 12, 13, which gap is called a crack gap. Therefore, such a molding tool 3 is also called a crack gap mold.

[0121] A capacitor plate 15, 16 is arranged on each half mold 12, 13. These capacitor plates 15, 16 are each made of a material with good electrical conductivity, such as copper or aluminum. A 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.

[0122] The two capacitor plates 15 , 16 are each formed from a plurality of segments 85 , 86 which are arranged adjacent to one another and are electrically and mechanically connected to one another. The segments 85 , 86 are detachable from one another.

[0123] By adding or removing individual segments 85, 86, the size of the first capacitor plate 15 formed by the segment 85 and the size of the second capacitor plate 16 formed by the segment 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 makes it possible to generate electromagnetic radiation between the capacitor plates 15, 16, in particular only in the region of the cavity 14. In regions where electromagnetic radiation is not required when fusing the foam particles, the generation of electromagnetic radiation can be avoided by removing individual segments 85, 86.

[0124] The segments 85 , 86 are each attached to an insulator 80 , 81 and form two opposing segment arrangements. The insulators 80 , 81 serve to hold the segments 85 , 86 in position on two opposing sides of the molding tool 3 .

[0125] The insulators 80, 81 with the segments 85 and 86 attached are mounted so that they can move relative to each other. This means that the mold halves 12, 13 of the molding tool 3 together with the segmented capacitor plates 15, 16 resting on the sides of the molding tool 3 can be moved towards and away from each other. Furthermore, the molding tool 3 can be replaced when the segment arrangements 85, 86 are moved apart from each other.

[0126] As an alternative, the segments 85, 86 may also be attached to the moulding tool 3 so that they are detachable from the moulding tool 3 and from each other. In this case, the two insulators 80, 81 or at least one of them may be omitted.

[0127] One of the segments 85 is connected to a generator 18 via an electric line 17 for transmitting a high frequency voltage forming an AC voltage source. The electrical connection of the segments 85 to each other causes a high frequency voltage to be applied to them, thereby forming a capacitor plate 15.

[0128] The segments 86 on the opposite side of the half-mold 13 forming the capacitor plate 16 are electrically connected to the ground 30, as is the generator 18. Since these segments 86 are also electrically connected to each other, only one of these segments is connected to the ground 30.

[0129] 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. In addition, most plastic materials can absorb RF radiation better than microwave radiation. Therefore, it is preferred to use RF radiation.

[0130] The mold halves 12, 13 each have a base body, which can be made of a material that is non-conductive and, in particular, substantially transparent to electromagnetic RF radiation, such as polytetrafluoroethylene (PTFE), polyethylene (PE), in particular ultra-high molecular weight polyethylene (UHMWPE), polyetherketone (PEEK). Preferably, only the capacitor plates 15, 16 are conductive. A "substantially transparent material" is a material that can be penetrated by electromagnetic radiation, in particular RF radiation. However, the material can be specially designed to have a certain electromagnetic RF radiation absorption coefficient in order to convert part of the electrical RF radiation into heat and heat the mold halves 12, 13. This will be explained in more detail below.

[0131] The moulding tool 3 can optionally be connected to a vacuum pump so that a vacuum can be applied to the mould cavity 14. This vacuum causes the moisture contained in the mould cavity 14 to be drawn out.

[0132] The capacitor plates 15, 16 may be provided with cooling means. In the present example, the cooling means are provided by a fan 20 which directs cooling air to the side of the capacitor plates 15, 16 facing away from the cavity 14. Cooling fins may be provided to increase the cooling effect.

[0133] Alternatively or additionally, cooling lines can also be arranged on the capacitor plates 15, 16, through which cooling lines a cooling medium is passed. Preferred cooling media are liquids, such as water or oil.

[0134] The device 1 can also be designed to have a steam generator and a steam supply device to the mold cavity 14 and / or the conveying line 4 to supply saturated dry steam to the mold cavity 14 for heating and / or wetting the foam particles during the process of conveying the foam particles from the material container 2 to the mold 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.

[0135] To illustrate further details of the device 1, Figure 2 A partial enlarged cross-sectional view of the device 1 is schematically shown, but in this example, Figure 1 Unlike the example shown, as another option, each section 86 of the second capacitor plate is connected to ground 30. In all other respects, Figure 1The instructions given in also apply to Figure 2 , and vice versa, similar elements in the figures have the same reference numerals.

[0136] The fastening means 82 , which are preferably designed as screws, serve to detachably fasten the sections 85 , 86 to the respective insulating body 80 or 81 .

[0137] The electrically conductive connecting element 83 is designed as an electrically conductive, flexible metal element in the form of a foil, for example a copper foil or a brass foil, for electrically connecting the segments 85 arranged adjacent to one another to one another and forming the first capacitor plate 15 .

[0138] The connecting element 83 electrically connects two or more adjacent segments 85 at their edges. When the segments 85 are fastened to the insulator 80, the conductive connecting element 83 is pressed against the edges of the segments 85. This creates an electrical connection for the capacitor plates 15 between the segments 85 thereof.

[0139] In the example shown here, due to the grounding of the individual segments 86 on the plate 16 , connecting elements 83 are not absolutely necessary on the second capacitor plate 16 , but they can optionally be provided and arranged here in the same way as for the first capacitor plate 15 .

[0140] On the contrary, Figure 1 In the example shown, they are arranged on both capacitor plates 15 , 16 , since only one of the sections 86 of the capacitor plate 16 is connected to ground 30 .

[0141] The electric line 17 designed as a high-frequency line connects one of the sections 85 to the generator 18 (see Figure 1 The section electrically connected to the generator 18 is designed as a high-frequency connection section or 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.

[0142] In this way, the segments 85 form a capacitor plate set 90, the combination of which makes it possible to form a first capacitor plate 15 which can be connected to an RF radiation source and whose dimensions can be adapted to the dimensions of the molding tool 3. The capacitor plate 15 can also be adapted to the dimensions of the cavity 14 in the molding tool 3.

[0143] The section 87 designed as an RF connection section and comprising a connection area for the line 17 for connection to the generator 18 forms a first capacitor plate section of the capacitor plate set 90 .

[0144] The other segments 85 form a second capacitor plate segment for forming the capacitor plate 15, i.e. the first capacitor plate segment 87 and the at least one second capacitor plate segment 85 are designed to form together the capacitor plate 15 and to form a capacitor plate group 90. The area of ​​the capacitor plate 15 that can be produced by the capacitor plate group 90 can be adapted to the dimensions of a molding tool 3 for producing a particle foam component, such as a sole or midsole or a part thereof.

[0145] The first capacitor plate segment 87 and the second capacitor plate segment 85 are designed to be fastened to the insulator 80 using fasteners 82 .

[0146] The section 86 of the second capacitor plate 16 arranged opposite the first capacitor plate 15 forms a further capacitor plate section of the capacitor plate group 90. The further capacitor plate sections 86 complement the capacitor plate group 90 by enabling the production of the second capacitor plate 16 and thus allow a complete capacitor to be formed (from the first and second capacitor plates 15, 16). They are designed for mounting on the insulator 81.

[0147] Both insulators 80 , 81 may be components of capacitor plate set 90 .

[0148] In the example shown here, a press 73 is also shown, which is connected to an insulator 80 on one side of the molding tool 3 via a cylinder-piston unit 76. The insulator 81 on the opposite side of the molding tool 3 is fixed so that the molding tool 3 can be pressed together between the two capacitor plates 15, 16, which are connected to the insulators 80, 81 on the side facing the molding tool 3.

[0149] Thus, the foam particles located 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 pressed together due to their thermal expansion caused by electromagnetic heating, but also by mechanically pressing the two mold halves 12, 13 of the molding tool 3 together.

[0150] Figure 3 Another possible way of connecting adjacent segments 85 and 86 of capacitor plates 15 and 16 is shown, as they are in FIG. Figure 1 and 2, and also in the subsequent other embodiments. The segments 85, 86 each have an edge region 88 protruding from the segment body on their edge, which is designed so that they interlock when the segments 85, 86 are joined to each other. The edge region 88 forms a stepped seam at the junction of the segments 85, 86. In this way, a particularly reliable electrical and mechanical connection is produced between the segments 85, 86, which can also be realized very cost-effectively.

[0151] Figure 4 An example of an arrangement of segments 85, 86 is shown, which form capacitor plates 15 and 16, respectively, and which may be produced from a capacitor plate group 90. The figure shows a view of the surface of a capacitor plate.

[0152] In this arrangement, the central segment 89 is arranged in the center and is surrounded by the additional segments 91. The central segment 89 has a square shape. The additional segments 91 each extend along one side of the central segment 89 and along one side of another additional segment.

[0153] In the example shown here, a first additional section 91 is provided, which extends along one side of the square, in addition to the central section 89. A second additional section 91 is provided, which extends along the other side of the square and along one side of the first additional section 91, a third additional section 91 is provided, which extends along the other side of the square and along the second additional section 91, and a fourth additional section 91 is provided, which extends along the remaining side of the square and along both sides of the additional section 91.

[0154] In this way, by combining several segments 85, 86 as capacitor plate surfaces, different rectangles can be formed. In addition, further additional segments can be provided to complete the arrangement or surround the arrangement in the form of a ring of further segments. The central segment 89 can also be formed as a rectangle.

[0155] In addition to rectangular and square shapes, other different sizes, shapes and geometries of the segments 85, 86 are possible, and thus capacitor plates of various shapes may be obtained.

[0156] Below, based on Figures 5 to 9 Further embodiments of the invention are explained, in which identical, similar or functionally equivalent elements are again labeled with the same reference numerals as in the previous figures and have already been explained above.

[0157] according to Figure 5The molding tool 3 of the device 1 is formed by two half-molds 12, 13, each of which has a matrix made of a non-conductive material that is transparent, in particular transparent to electromagnetic RF radiation. The material is PTFE, PE, PEEK or another material that is transparent to RF radiation. The half-molds 12, 13 define a cavity 14. In the present design example, the cavity 14 has an inner boundary surface 19, which has a contoured shape that deviates from a flat surface.

[0158] The mold halves 12, 13 each have a flat outer surface 21, on which are arranged the capacitor plates 15, 16. The space between the shaped boundary surface 19 and the outer surface 20 is filled with a material that is transparent to electromagnetic radiation.

[0159] With this molding tool 3, three-dimensionally shaped particle foam parts can be produced, whereby the shape of the particle foam part is defined by the inner boundary surfaces 19 of the mold halves 12, 13. Such a molding tool 3 is suitable, for example, for producing small particle foam parts with a substantially uniform density. It can also be used to produce soles or midsoles or parts thereof.

[0160] The capacitor plates 15, 16 are flat and as mentioned above Figures 1 to 4 The first capacitor plate 15 is formed by adjacent segments 85 . The second capacitor plate 16 is also formed by adjacent segments 86 .

[0161] Each set of segments 85 and 86 is attached to insulators 80 and 81, respectively, by fasteners 82, whereby the segments 85 of the first capacitor plate 15 are mechanically and electrically conductively and detachably connected to each other, as described above with reference to Figure 2 and 3 Likewise, the sections 86 of the second capacitor plate 16 are mechanically and electrically conductively connected to one another in a detachable manner.

[0162] The segments 85 , 86 and optionally also the insulators 80 , 81 are components of the capacitor plate set 90 as described above.

[0163] A problem with large or thick particle foam parts is that they heat up more in the middle than at the edges, which can destroy the particle structure. In order to avoid uneven heating of the center area and the edge area of ​​the particle foam part, the molding tool 3 can be tempered and / or additional heat can be added to the foam particles in the cavity 14, for example in the edge area, as described in DE 102016 100 690 A1.

[0164] By means of a modification of the device 1 , which will be explained in more detail below, it is possible to disconnect the individual segments 85 , 86 even before the end of the fusing process, in order to prevent the foam particles located between the individual segments from overheating.

[0165] The above embodiments each have flat capacitor plates 15, 16. In another embodiment, the molding tool 3 can be designed so that the capacitor plates 15, 16 are adapted to the shape of the particle foam part to be manufactured or the cavity 14. This is beneficial for example for the manufacture of soles or midsoles or parts thereof with complex three-dimensional geometries to promote uniform fusion of the foam particles throughout the part.

[0166] Figure 6 The embodiment of the device 1 shown has two mold halves 12, 13 which define a stepped cavity 14 by their inner boundary surfaces 19. The outer surfaces 21 of the mold halves 12, 13 are adapted to the contour of the respective inner boundary surface 19 of the respective mold half 12, 13. In other words, the inner boundary surface 19 mirrors the respective outer surface 21 of the mold halves 12, 13, so that the molding tool 3 can be formed with a uniform thickness from the outer surface 21 to the inner boundary surface 19. On the outer surface 21, preferably, small structures of the inner boundary surface 19 are smoothed out.

[0167] The molding tool 3 thus has two shaped mold halves 12, 13, and bears against its outer surface 21 a correspondingly shaped, segmented capacitor plate 15, 16, which is formed from several segments 85 or 86 and is otherwise as described above with reference to Figures 1 to 5 Designed as described.

[0168] This adaptation of the shape of the capacitor plate with the sections 85, 86 to the shape of the particle foam component to be produced is particularly useful for shell-shaped particle foam components, such as boxes or bowls with spherical sections, or, as mentioned above, for soles or midsoles or parts thereof.

[0169] In the example shown here as well, the insulators 80 , 81 serve to hold the segments 85 , 86 in their position. The sides of the insulators facing the mold halves are adapted to the shape of the outer surfaces 20 of the mold halves 12 , 13 .

[0170] Figure 7 Another embodiment is shown, in which the first capacitor plate 15 formed by the segment 85 together with the insulator 80 and the pressing tool formed by the press 73 and the cylinder-piston unit 76 are generally described above with reference to Figures 1 to 4 Settings. Special reference Figure 2 and related descriptions.

[0171] In this embodiment, the molding tool 3 has a first mold half 12 and a second mold half 13, which form a cavity 14 between them, in which the foam particles 29 to be fused are arranged. In addition to the description of the molding tool 3 that now follows, reference is made to German patent application 102019127680.2, in which further details of the molding tool 3 are explained.

[0172] The second mold half 13 or at least a part thereof is electrically conductive or made of an electrically conductive material.The molding tool 3 can be used as part of the apparatus 1 , wherein the second mold half 13 is used as a second capacitor plate and is electrically connected to the ground 30 for this purpose.

[0173] The second mold half 13 has a base 24 made of an electrically conductive material. This base 24 consists, for example, of aluminum, copper or an alloy with good electrical conductivity. It is optionally provided with an electrically insulating coating 28 and forms a bottom wall 31. The electrically conductive base 24 has an electrical connection to the generator 18 or to ground 30.

[0174] The generator 18 is electrically connected to the segmented capacitor plates 15 via high frequency lines 17 (see Figure 1 , 5 and 6) generating an electromagnetic wave or an alternating voltage relative to ground potential 30, which is applied to the substrate 24 of the second mold half 13. This generates an alternating electromagnetic field in the cavity 14 between the segmented capacitor plates 15 and the substrate 24, in particular RF radiation.

[0175] The circumferential side walls 32 of the second mold half 13 are made of electrically non-conductive material, in particular plastic material, and extend from the bottom wall 31 and on the side of the mold half 13 in the direction of the first mold half 12 , thereby laterally delimiting the cavity 14 .

[0176] However, it is also possible that both the bottom wall 31 and the side walls 32 are formed from the electrically conductive matrix 24. However, it is important that there is no electrically conductive connection between the two mould halves 12,13.

[0177] The first mold half 12 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.

[0178] The first mold half 12 forms a plunger which can enter the cavity formed by the second mold half 13, thereby sealing the mold cavity 14. The tight seal between the two mold halves 12, 13 is at least tight enough to prevent the foam particles 29 from escaping. However, the mold cavity 14 does not have to be sealed airtight.

[0179] The first mold half 12 has an inner boundary wall 34 which is shaped and defines the cavity 14. Starting from the boundary wall 34, several webs 35 extend in the direction of the first capacitor plate 15 towards an optional cover element 37. The webs 35 serve to support the boundary wall 34. A cavity 36 is formed between the webs 35 in the first half of the mold 12, which significantly reduces its mass.

[0180] This results in a beneficial reduction in the influence of the electromagnetic field strength in the cavity 14 , which significantly increases the flexibility of use and shaping of the cavity 14 and the plunger mold half 12 .

[0181] Furthermore, in addition to the flexibility obtained by varying or adjusting the surface of capacitor plate 15 by different combinations of segments 85, cavity 36 can also be used to tailor plunger mold half 12 to influence the electromagnetic field in cavity 14. Trimming can also be used to achieve a particularly uniform or even distribution of field strength in cavity 14.

[0182] A trim body (not shown) made of a dielectric material can also be inserted into the cavity 36. Due to the polarization properties of the dielectric, the alternating electromagnetic field is concentrated by the dielectric in the path of the field lines in the adjacent area of ​​the cavity 14. In the area along the same field line path, which is kept empty by the dielectric, the field is not concentrated in the adjacent area of ​​the cavity 14, so that the field is weaker in this area of ​​the cavity 14 than in the area of ​​the cavity 14 adjacent to the dielectric. By using trim bodies of different sizes, shapes and dielectric constants, the electric field can therefore be additionally influenced in different ways. The dielectric constant of the dielectric is greater than the dielectric constant of a vacuum or air.

[0183] All these measures additionally contribute to the fact of specifically targeting electromagnetic fields, which leads to an even further increased effectiveness of the disclosed device and promotes uniform fusion of the particles throughout the component, also for complex geometries as encountered with, for example, soles or midsoles or parts thereof.

[0184] The two mold halves 12, 13 can be moved relative to each other by means of a press 73 and a predetermined force can be applied to them. For this purpose, the press 73 is connected via a cylinder-piston unit 76 to an insulator 80, to which the first capacitor plate 15 formed by a segment 85 is attached, as described above with reference to Figure 2 In order to press the two mold halves 12 , 13 together, the first mold half 12 is moved in the direction of the second mold half 13 by means of a press 73 via the movable segmented capacitor plate 15 .

[0185] A through hole for inputting foam particles 29 is provided on the second half mold 13, which is referred to as a filling opening 33. The filling syringe 10 (see Figure 1 ) is connected to the filling opening 33. The filling syringe 10 differs from conventional filling syringes in that it does not have a closing mechanism for closing the filling opening 33, as explained in more detail below.

[0186] The first mold half 12 has one or more through holes (not shown) to allow air to escape.

[0187] The filling opening 33 and the ventilation opening are arranged on a portion or region of the second mold half 13, in particular on an edge region, which portion or region is covered by the first mold half 12 when the molding tool 3 is closed. Therefore, when the molding tool 3 is closed by inserting the first mold half 12 into the cavity formed by the second mold half 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.

[0188] Since both mold halves 12, 13 delimit the cavity 14 and simultaneously form a capacitor plate, the distance between the "capacitor plate" and the cavity 14 is very small. As a result, the losses of electromagnetic radiation are 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, this tool allows very efficient fusion of foam particles 29 to form particle foam parts.

[0189] Figure 8 A device 1 for producing a particle foam component according to a further exemplary embodiment is shown, wherein Figure 7 Similarly, the second mould half 13 is formed from a conductive material and is connected to ground potential 30, thereby acting as a second capacitor plate.

[0190] The first mold half 12 is non-conductive and as in Figure 7 In the version shown in , a boundary wall 34 is included which is shaped and fixedly connected to a cover element 37 via a partition 35. Here, too, a cavity 36 is formed between the partitions 35 to influence the electromagnetic field in the cavity 14 between the two half-moulds 12, 13, as explained in detail above.

[0191] and Figure 7 In contrast to the embodiment shown, a circumferential side wall 32 is formed on the first mold half 12, which laterally closes the cavity 14. Within the side wall 32, a portion 38 of the electrically conductive second mold half 13 projects into the cavity 14 formed by the circumferential side wall and closes the cavity 14 on this side, while being closed on the opposite side by the boundary wall 34 of the first mold half 12.

[0192] When the two mold halves 12 , 13 are pressed together by the segmented capacitor plate 15 being pressed toward the first mold half 12 by means of the press 73 , the foam particles 29 located in the mold cavity 14 are pressed by the projections 38 .

[0193] The filling opening 33 for filling with foam particles 29 leads to the mold cavity 14 and is opened by separating the two mold halves 12, 13 and closed by moving the two mold halves 12, 13 toward each other, as described above, including with reference to Figure 7 for further details.

[0194] Fig. 9A further embodiment of the invention is shown in which the sections of the capacitor plates are electrically insulated from one another.

[0195] In the device 1 shown here, the segments 85 of the first capacitor plate 15 formed by them are permanently attached to an insulator 80, electrically insulated from one another, each segment being individually connected to a generator 18 via a tunable resonant circuit 40. The generator 18 is connected to ground potential 30.

[0196] The segments 86 forming the second capacitor plate 16 are electrically connected to the ground 30, as is the generator 18. The segments 86 are permanently attached to the insulator 81. If, as is the case here, all segments 86 are connected to the ground, it is not absolutely necessary to arrange the segments 86 electrically isolated from each other. It is also possible to make the second capacitor plate 16 continuous or unsegmented or divided into a plurality of segments and to connect it electrically to the ground 30.

[0197] Where the segments 86 of the second capacitor plate 16 are electrically isolated from one another, the generator 18 may be connected to each segment 86 instead of the ground 30 , in which case the segments 86 are not connected to the ground 30 .

[0198] As above reference Figure 2 As described, 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 segment 85 of the first capacitor plate 15 attached thereto to be pushed toward 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.

[0199] The insulators 80, 81 and the segments 85, 86 and the tunable resonant circuit 40 form a capacitor plate set 90. The segments 85, 86 are designed as capacitor plate segments and can be designed as in the above-described versions and embodiments. They can also have a geometric shape and form a two-dimensional arrangement as described above.

[0200] The molding tool 3 can be designed as one of the above-mentioned types and embodiments. Small modifications may be required to arrange the molding tool according to Fig. 9 The capacitor plates 15, 16 are provided.

[0201] Fig.10 and 11 Used to explain below Fig. 9 The operation of the device shown in . Fig.10 Schematically shows the Fig. 9 Simplified equivalent circuit diagram of the device.

[0202] Fig.11 A single device for controlling the electrical power supplied to a segment pair 85, 86 is shown in a schematic simplified circuit diagram. In particular, Fig.11 The generator 18 and the partial capacitor formed by the segments 85, 86 of the encapsulated half-molds 12, 13 are schematically shown in a circuit diagram, as well as a connecting line (hollow waveguide or coaxial line) 46 suitable for transmitting electromagnetic waves, through which the electromagnetic waves are transmitted from the generator 18 to the molded partial capacitors 85, 86. The hollow waveguide forming the connecting line 46 is preferably designed as a coaxial air line with a conductive inner tube and a conductive outer tube. The dimensions of the coaxial air line are designed so that high-voltage signals can be reliably transmitted. The characteristic impedance is preferably set to about 50Ω.

[0203] In this connecting line 46, a generator-side inductance 47 and a tool-side inductance 48 are symbolically shown. These inductances are caused by the line itself, whereby the length of the individual line sections determines the value of the individual inductances. A 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.

[0204] The generator side capacitor 51 is connected in series with the generator 18 and the generator side inductor. The generator side capacitor 51 and the generator side inductor 47 form a generator resonant circuit 52. At least the generator side capacitor 51 or the generator side inductor 47 can be variably arranged, for example by using a capacitor with spaced capacitor plates or by providing connecting line sections of different lengths. It is also possible that both the generator side capacitor 51 and the generator side inductor 47 are variable. The generator side capacitor 51 can be equipped with a servomotor which changes the distance between the two capacitor plates when actuated, 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.

[0205] 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 electrical power is transmitted 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 transmission of electrical power can be controlled in a targeted manner, wherein the greater the difference in the resonant frequencies of the two resonant circuits 50, 52, the lower the power transmitted. Therefore, the tuning of the generator resonant circuit 52 can be used to specifically adjust the electrical power introduced into the cavity 14.

[0206] In this embodiment, the resonant frequency of the generator resonant circuit 52 is changed. The resonant frequency of the tool resonant circuit 50 can also be changed. This has the same effect on power transmission. However, it is more difficult to provide a variable capacitor or variable inductor on the tool side than on the generator side.

[0207] Thus, the segments 85, 86 each form a tool capacitor or a tool sub-capacitor or a tool part capacitor, which is individually connected to the generator 18 via its own tunable resonant circuit 40. Thus, the resonant circuit 40 comprises a tool resonant circuit 50 as well as a 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 transmitted 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 device of the capacitor plate segments 85, 86.

[0208] The resonant circuit 40 thus forms a switching device 41 for connecting or disconnecting the capacitor plate segment 85 to or from the capacitor plate 15 or connecting or disconnecting the capacitor plate segment 86 to or from the capacitor plate 16, respectively. The segments 85, 86 can be connected or disconnected individually or in groups as partial capacitors to form the capacitors 15, 16.

[0209] This means that the electromagnetic radiation source 18 is part of the generator resonant circuit 52, while any connecting lines used to guide the electromagnetic waves together with the corresponding pair of sections 85, 86 forming part of a capacitor form the tool resonant circuit 50. By varying the inductance or capacitance, the tool resonant circuit 50 can be tuned in its resonant frequency and form a tunable resonant circuit.

[0210] 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 tuning thereof, wherein (at least) one of the two resonant circuits is arranged as a tunable resonant circuit. In this way, the segment in question is added to or removed from a capacitor plate formed by several such segments, which applies electromagnetic radiation to the molding tool during the fusion process.

[0211] By controlling the energy supply on the individual lines, it is possible to set and control which segments 85 of the capacitor plate 15 (and / or the segments 86 of the capacitor plate 16) are operated and which segments are not operated. By switching the individual segments on and off by means of resonant circuit tuning, the size of the capacitor plates 15, 16 can be adapted to the size 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 segments 85, 86 to the molding tool 3 in order to adapt the surface of the capacitor plates 15, 16. It is also not necessary to mechanically interrupt or mechanically switch the connecting lines 46 between the generator 18 and the individual segments 85, 86.

[0212] For further details, we refer to the already mentioned publication DE 10 2016 123 214 A1, which describes the circuit for tuning in more detail.

[0213] Fig.12 A device for controlling the electric power supplied to the tool capacitors 15, 16 is shown in a schematically simplified circuit diagram. A generator 18 is connected to the tool capacitors 15, 16. A measuring capacitor 53 is connected in parallel with the tool capacitors 15, 16. Its capacitance is a 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.

[0214] The measuring unit consisting of the measuring capacitor 53 and the diode 56 is separated from the tool capacitors 15, 16 by an isolating capacitor 59. The isolating capacitor has a high dielectric strength. The capacitance of the isolating capacitor 59 is smaller than the capacitance of the measuring capacitor 53, which means that the voltage drop across the isolating capacitor 59 is higher than the voltage drop across the measuring capacitor 53. The ratio of the capacitance of the isolating capacitor 59 to the capacitance of the measuring capacitor 53 is preferably 1:100 or 1:1.000 or 1:10.000. Therefore, the voltage applied to the tool capacitors 15, 16 is reduced in the measuring unit 53, 56 so that the voltage is within the measuring range of the voltage measuring device 55 and can be reliably detected by the voltage measuring device.

[0215] 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 which is reduced as a function of the ratio of the capacitance of the measuring capacitor 53 to the capacitance of the isolating capacitor 59. By providing the diode 56, only an oscillation half of a certain polarity is generated. The diode 56 thus forms a rectifier for the voltage occurring across the measuring capacitor 53. This measurement voltage is measured by the voltage measuring device 55 and converted into a measurement signal. The measurement signal is forwarded to the control device 57, which automatically controls the generator 18 to deliver a predetermined electrical power in order to generate a specific voltage across the tool capacitor or a specific measurement voltage across the measuring capacitor, which is a portion of the voltage across the tool capacitor.

[0216] Fig.11 The device shown can also be arranged in such a way that for several or all pairs of segments 85, 86, according to Fig.12 Means are provided for controlling the electrical power supplied to the capacitor 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 the need for any moving parts. There is also no need to calibrate the resonant circuits (generator resonant circuit, tool resonant circuit) 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.

[0217] Reference below Figure 1 The embodiment of the invention describes an example of a process for producing a particle foam component, such as a sole or midsole or a part thereof. Foam particles are filled into a cavity 14 of a 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.

[0218] The capacitor plates 15, 16 or at least one of them is formed by several segments 85, 86. By combining a suitable number of radiation generating segments 85 and / or 86, the area of ​​the capacitor plates 15, 16 is adapted to the dimensions of the moulding tool 3.

[0219] 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 being heated by electromagnetic radiation in the moulding tool 3, i.e. heat is provided to the foam particles by electromagnetic RF radiation. This fuses them together to form a particle foam part.

[0220] The particle foam part produced is then demoulded and removed from the molding tool.

[0221] According to a preferred embodiment, the segments 85, 86 are detachably electrically and mechanically connected to combine them. Fig. 9 In the variant shown, the segments 85, 86 are arranged electrically insulated from one another. The segments 85, 86 are switched on or activated, or switched off or deactivated, in the capacitor plates 15, 16 by tuning the resonant circuit 40 connected to the respective segment. In this way, they are combined with one another depending on the size and geometry of the molding tool 3.

[0222] This allows the surface of the capacitor plates 15, 16 emitting electromagnetic radiation to be adapted to different moulding tools 3. As a result, no mechanical removal or mechanical addition of the segments 85, 86 is required when changing the moulding tool 3. No mechanical separation or connection of the segments to the radiation source 18 is required in order to adapt the surface of the capacitor plates to the moulding tool 3. This means that different moulding tools 3 (e.g. corresponding to different sole or midsole sizes, or to different sole or midsole configurations) can be electromagnetically irradiated one after the other in a very short period of time.

[0223] To perform this process, for example, in different versions and embodiments, Figures 1 to 11 One of the devices is used as shown, or one of the devices is used as discussed elsewhere in this disclosure. Moreover, the capacitor plate set 90 described above can be used to perform a manufacturing process.

[0224] Fig.13a -f shows (a part of) a device 1 with a capacitor plate 16 comprising several sections 86 at an adaptable distance d from the cavity 14 , and corresponding measurement results obtained from a number of tests run on such a device 1 .

[0225] The overall construction of the device 1 may be of the same or similar design as any other device discussed so far herein (particularly the embodiments of the device 1). Therefore, all options, embodiments, modifications and features that have been discussed may also be used in the present invention as will be described with reference to the present invention. Fig.13a -f or in combination therewith (of course, as far as this is physically and technically possible). The compatibility between the different disclosed aspects and embodiments is also confirmed by the fact that the same reference numerals as above will also be used for elements and components with the same function or at least functionally similar or equivalent.

[0226] The disclosed device 1 can be used in particular for producing particle foam parts, in particular shoe soles or parts of shoe soles (e.g. midsoles or parts thereof). It comprises a molding tool 3 formed by (at least two) mold halves 12 and 13. The molding tool 3 defines a mold cavity 14 (in particular a mold cavity 14) bounded by the two mold halves 12 and 13. Fig.13aParticles 29 of foamed or expanded material (e.g., eTPU particles, or one of the other materials mentioned herein at this point) are loaded into the cavity 14 and then fused or melted together (primarily at their surfaces to maintain the internal foam structure, see Fig.13d ) to form a molded part.

[0227] The device also comprises (at least two) capacitor plates 15 and 16, which are arranged adjacent to the cavity 14. "Adjacent" here means that the two capacitor plates 15 and 16 are arranged on two opposite sides thereof and comprise the cavity 14 between them, so 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.

[0228] 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, comprises several segments 86 at an adaptable distance d from the cavity 14, i.e., they are arranged in the z direction (e.g. Fig.13a and 13d The position of the segments 86 (as shown) can be changed so that the distance d of the radiation emitting surface of each segment 86 from the cavity (e.g. measured relative to the wall of the cavity 14 or a specific reference point within the cavity 14) also changes. Therefore, the distance between the two capacitor plates 15 and 16 is also locally changed by adjusting the position of the segments 86. The distance d of the segments 86 to the cavity 14 can be adjusted individually by mechanical and / or electrical actuator means (e.g., by hand, or by a wrench, or by an electric motor or linear actuator, or by a gear driven by an electric motor, etc., depending on the specific design of the segments 86).

[0229] For one of the segments, such as Fig.13a As shown in the segment 86a in FIG. 8 , the distance to the cavity 14 is denoted as d and the distance to the opposing capacitor plate 15 is denoted as D. If the position of the segment 86a in the z direction changes, both values ​​change.

[0230] Segment 86 is electrically connected to a conductive electrode body 100, which in the embodiment shown and discussed herein is at ground potential and is provided as a block of metal. However, in other cases it may instead be connected to the radiation generator and the opposing capacitor plate may be grounded. Aluminum is a choice because it has a relatively low weight and can be easily processed.

[0231] exist Fig.13a In the case shown in FIG. 8A , the segment 86 is provided as a screw (eg a pin is also possible) adjustably connected to the electrode body 100 . Here, the screw 86 is a metal screw screwed into a corresponding thread provided in the electrode body 100 .

[0232] Although in Fig.13a -f are all of the same type and size and have the same head size, but this is not a rule, and the type, length, thickness and head size of the screws 86 may also vary across the electrode / capacitor plate 16. For example, smaller screws or screw heads may be used in areas where there are more screws per unit area, i.e., areas of the electrode / capacitor plate 16 where the density of segments 86 is higher (not shown in the figure; in Fig.13a -f, the density of segments / screws 86 is constant across the capacitor plate 16, except at the edges of the plate).

[0233] The segments / screws 86 are arranged in a two-dimensional grid, i.e. Fig.13a -f is a square grid in the example. The grid is Fig.13b and 13c 130. Other types of grids are also possible, such as rectangular, triangular or hexagonal grids, or "hybrid" grids comprising different geometries. The grid density (i.e. the number of adjustable sections / screws 86 per unit area) can also be varied locally, as already explained above, even if this is not the case in Fig.13a Not shown in -f.

[0234] In order to allow the screws 86 to be screwed completely into the electrode body 100 without hitting the floor below (or parts of the device 1), the capacitor plate 16 with its electrode body 100 is mounted at its four corners on four aluminum blocks 120, which raise it a certain distance from the floor and leave room for the screws 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 position that can be achieved is when the screws 86 are almost completely screwed out of the electrode body 100, but not completely screwed out. Generally, a little play will be maintained to avoid accidental disengagement of one of the screws 86 from the electrode body 100 and / or a general loss of stability when approaching the maximum height of the corresponding screw 86 above the electrode body 100.

[0235] The cover plate 110 of non-conductive material is arranged on the electrode body 100 (see Fig.13c ;exist Fig.13b 86) and includes openings in which the screws 86 are arranged. This not only helps to stabilize the screws 86 when they are in an intermediate position or in particular in a high position, i.e. when they are screwed out to a greater extent from the electrode body 100. It also provides a stable and uniform support surface for adjacent parts of the device 1, in particular the molding tool 3, to rest on (see Fig.13a , 13c , 13d, 13e and 13f).

[0236] Such a cover plate 110 may generally be made of or include an electrically insulating cover. Preferably, the cover plate 110 is made of or includes one or more of the following materials: polytetrafluoroethylene (PTFE), polyethylene (PE), in particular ultra-high molecular weight polyethylene (UHMWPE), polyetherketone (PEEK), thermoplastics, duroplast, polyethylene terephthalate (PET), polyoxymethylene (POM), polystyrene (PS), insulating mineral materials. Fig.13e In the case shown, it is made of PTFE.

[0237] One option is that each adjustable segment / 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 segment 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 segments / screws 86 are set can facilitate the operation of the device 1. Fig.13a , 13b , 13d, 13e and 13f, exemplary screws set to the low position, the middle position and the high position are represented by reference numerals 86l (for low), 86m (for middle) and 86h (for high), respectively. Fig.13d , as shown by dashed oval 86x, one of the screws has been completely removed (alternatively, it may be electrically isolated from capacitor plate 16 / ground potential).

[0238] The position of the segments / screws 86 can be adjusted when the cavity 14 is irradiated or filled with electromagnetic radiation. However, usually, an automated activation / adjustment mechanism (as described above) may have to be employed for this purpose, since manual adjustment is usually not permitted or possible during operation of the device 1 to avoid injury.

[0239] As described and explained above, adjusting the position of one or more segments / screws 86 affects the field strength distribution of the radiated electromagnetic field within the cavity 14. For example, in Fig.13d, four regions or positions p1, p2, p3 and p4 are schematically represented within the cavity 14. These regions have screws 86 set at different positions / heights below them. For example, position p1 has a screw set between the middle position and the low position directly below it, position p2 has no screws below it at all (because the screws at position 86x have been removed), position p3 again has a screw set between the middle position and the low position directly below it, and position p4 has a screw set between the middle position and the high position directly below it. In this way, the electric field strength distribution and the temperature and fusion conditions can be adjusted and controlled at different positions p1 to p4.

[0240] Fig.13e and 13f The experimental results shown provide further understanding in this regard. On the left hand side of both figures, different configurations of the apparatus 1 are schematically shown, which were used to study the heating rate and temperature within the moulding tool 3 at different positions of the screw 86 in the capacitor plate 16. In each of the three cases studied, two reference positions within the moulding tool are considered, Fig.13e -f are indicated as p1 and p2, p3 and p4 and p5 and p6, one at the front of the tool (p1, p3 and p5 respectively) and one at the back of the tool (p2, p4 and p6 respectively). Using a constant setting of a radiation generator (not shown) and as Fig.13e The different settings of screw 86 shown on the left hand side of -f, the heating rate / temperature at positions P1-P6 are recorded as a function of time, yielding Fig.13e -f The measurement curves C1-C6 are shown on the right hand side.

[0241] Fig.13e The x-axis of the measurement curve graph on the right hand side of -f shows time (the distance between two adjacent scales or grid lines on the x-axis corresponds to Fig.13e and 13f 43 seconds in the y-axis), and the y-axis shows the temperature (in Fig.13e In the range of 20℃ to 140℃, and Fig.13f in the range of 20°C to 160°C).

[0242] exist Fig.13e In the upper case where all screws are shown arranged in the middle / intermediate position 86m, measurements at positions P1 and P2 result in measurement curves C1 and C2, respectively.

[0243] exist Fig.13e In the illustrated case where all screws are set in the lower position 861, measurements at positions P3 and P4 produce measurement curves C3 and C4, respectively.

[0244] exist Fig.13fIn the case shown, the screw in the front half of the tool is set to the middle position 86m, the screw in the rear half of the tool is set to the low position 861, and the measurements at positions P5 and P6 produce measurement curves C5 and C6, respectively.

[0245] As can be inferred from the results, setting the position of the screw 86 corresponding to a given measurement position to an intermediate position 86m results in a greater heating rate (i.e., a greater increase in temperature per unit time = slope of the corresponding measurement curve) and a greater maximum temperature than setting the screw 86 to a low position 86l. Further setting one or more screws 86 to a high position, or removing one or more screws 86 altogether, will further change the heating rate / maximum temperature according to this principle (e.g., with a constant setting of a given energy source, the higher the screw position in the z-direction, the greater the heating rate and maximum temperature).

[0246] In About Fig.13e The maximum temperatures reached in the experiments shown and discussed are about 135°C at positions P1 and P2 (see curves C1 and C2) and about 115°C at positions P3 and P4 (see curves C3 and C4), as well as about Fig.13f The maximum temperatures achieved in the experiments shown and discussed, i.e., about 145° C. at position P5 (see curve C5) and about 125° C. at position P6 (see curve C6), were tailored to the specific material used to conduct these experiments, i.e., expanded thermoplastic polyurethane (eTPU) pellets 29. In other words, the temperatures achieved were set to fall within the processing window of that particular material.

[0247] When using particles 29 made of or including different kinds of materials, it is generally necessary to adjust the maximum temperature value to the specific processing characteristics and the available processing window of the material used. Typically, the maximum temperature for processing any material mentioned herein will not exceed 270°C. For example, by increasing the applied voltage, the maximum temperature value achieved 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 achieved (and generally also results in, for example, a change in the heating rate). As described above and discussed, adjusting the segment / 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, so these factors are interrelated and must be balanced with each other, as understood by those skilled in the art.

[0248] Also, materials with higher dielectric loss factors will generally heat faster and more intensely, so this also needs to be considered when swapping materials and adjusting, for example, the voltage, frequency and / or position of the segments / screws 86 and the duration of the manufacturing process.

[0249] In addition to the above-mentioned possibility 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 be supplemented by the "dynamic" adjustment possibility provided by the section 86 with an adjustable distance d to the cavity 14 disclosed herein.

[0250] The fifth aspect of the invention is related to the fourth aspect and may 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 part of a sole from foam particles 29.

[0251] In one embodiment, the method includes: a.) loading the particles 29 into the cavity 14 of the 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 includes several segments 86 having an adaptable distance d from 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 irradiating electromagnetic field within the cavity 14 by changing the adaptable distance d from the segments 86 to the cavity 14.

[0252] The alteration may occur before and / or during irradiation of the cavity 14 with electromagnetic radiation.

[0253] The foam particles 29 may include or consist of one or more of the following base materials: thermoplastic polyurethane (TPU), polylactic acid ester (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 comprising so-called bead foams, also referred to in the art as pellet / particle foams. Typically, the foams obtained by using connected foam particles are designated by the name "e" to indicate the bead form of the polymer foam component, such as eTPU.

[0254] In conclusion, from the above Fig.13aA discussion of the different options, modifications and embodiments possible within the scope of the present disclosure of the device 1 of -f, the skilled person understands how these options, modifications and embodiments are translated into corresponding steps of a method for operating such a device 1 to manufacture a particle foam part, in particular a sole or a part of a sole, from foam particles 29. In order to avoid unnecessary repetitions, reference is therefore made to the above explanations.

[0255] Reference numerals list

[0256] 1 Device

[0257] 2 Material containers

[0258] 3 Molding tools

[0259] 4. Pipeline

[0260] 5 Base

[0261] 6 Compressed air lines

[0262] 7 Compressed air source

[0263] 8 Propulsion nozzle

[0264] 9 Compressed air lines

[0265] 10 Filling Syringe

[0266] 11 Compressed air pipeline

[0267] 12 Half mold

[0268] 13 Half mold

[0269] 14 Cavity

[0270] 15 First capacitor plate

[0271] 16 Second capacitor plate

[0272] 17 Electrical connection wire

[0273] 18 Generator / AC voltage source

[0274] 19 Limiting surface of half mold (inside)

[0275] 20 Fan

[0276] 21 Outer surface of half mold

[0277] 24 Matrix

[0278] 28 Insulation coating

[0279] 29 Foam particles

[0280] 30 Ground potential

[0281] 31 base wall

[0282] 32 Circumferential side wall

[0283] 33 Filling opening

[0284] 34 Boundary Wall

[0285] 35 Bulkhead

[0286] 36 chambers

[0287] 37 Cover element

[0288] 38 protrusion

[0289] 40 Resonance Circuit

[0290] 41 Switchgear

[0291] 46 Connection line

[0292] 47 Generator side inductance

[0293] 48 Tool side inductance

[0294] 49 Tool side capacitor

[0295] 50 Tool resonant circuit

[0296] 51 Generator side capacitor

[0297] 52 Generator resonant circuit

[0298] 53 Measuring capacitor

[0299] 54 Coaxial Cable

[0300] 55 Voltage measuring device

[0301] 56 diode

[0302] 57 Control Device

[0303] 58 Inductor

[0304] 59 Isolation capacitor

[0305] 73 Press

[0306] 76 Cylinder-piston unit

[0307] 80, 81 Insulator

[0308] 82 Screws

[0309] 83 Electrical connection components

[0310] 85, 86 Section / Tool Capacitor / Screw

[0311] 86a Segment / screw

[0312] d Distance to the cavity

[0313] D is the distance to the opposing capacitor plate

[0314] 86h High position segment / screw

[0315] 86m Intermediate segment / screw

[0316] 86l Low section / screws

[0317] 86x Completely removed segments / screws

[0318] 87 Generator connection section / first capacitor plate section

[0319] 88 Boundary Segment

[0320] 89 Central section

[0321] 90 capacitor plate set

[0322] 91 Attachment section

[0323] 100 Electrode body

[0324] 110 Cover

[0325] 120 Bump

[0326] 130 Grid

[0327] p1-p4 reference point

[0328] P1-P6 Measurement location / area

[0329] C1-C6 measurement curve

[0330] Further embodiments are described below to facilitate understanding of the present invention:

[0331] 1. A device for producing a particle foam component, in particular a shoe sole or midsole or a part thereof, comprising:

[0332] A molding tool (3) defining a mold cavity (14), wherein at least two capacitor plates (15, 16) are arranged adjacent to the mold 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 mold halves (12, 13),

[0333] Therein, at least one of the two capacitor plates (15, 16) is formed from several segments (85, 86), so that the surface of the capacitor plates (15, 16) can be adapted to the dimensions of the molding tool (3).

[0334] 2. A device according to example 1, wherein the segments (85, 86) of one or both capacitor plates (15, 16) are detachably electrically and mechanically connected to each other.

[0335] 3. The device according to example 1 or 2 comprises a conductive connecting element (83) which electrically connects two or more segments (85, 86) to each other at their edges.

[0336] 4. A device according to any of the preceding examples, wherein the segments (85, 86) have portions (88) at their edges which interlock when the segments (85, 86) are joined together.

[0337] 5. A device according to any of the preceding examples, wherein the segments (85, 86) are detachably attached to the insulator (80, 81).

[0338] 6. A device according to any of the preceding examples, wherein at least one segment (87) of one or both capacitor plates (15, 16) formed by the segments (85, 86) is electrically connected to the radiation source (18).

[0339] 7. An apparatus according to Example 1, wherein the segments (85, 86) of one or both capacitor plates (15, 16) are permanently attached to the insulator (80, 81) and can be individually switched on or off to adjust the size of the capacitor plates (15, 16).

[0340] 8. The device according to example 7, wherein the individual segments (85, 86) are electrically insulated from each other and each segment is separately connected to the radiation source (18) via a high-frequency line (17).

[0341] 9. An apparatus 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, so that the radiation supply can be adjusted by tuning the tunable resonant circuit.

[0342] 10. A device according to any of the preceding examples, wherein the segments (85, 86) together form shaped capacitor plates (15, 16).

[0343] 11. A device according to any of the preceding examples, wherein the segments (85, 86) are arranged only on one side of the cavity (14) and capacitor plates (15, 16) are formed on said one side, and / or the half mold is conductive and serves as a capacitor plate.

[0344] 12. A device according to any of the preceding examples, wherein at least one of the capacitor plates (15) formed by the segments (85, 86) is electrically connected to the radiation source (18), while the other capacitor plate (15) or its segment (86) is electrically grounded.

[0345] 13. A device according to any of the preceding examples, wherein the segments (85, 86) each have a geometric shape which, when combined, produces capacitor plates (15, 16), the geometry of which is adapted to the geometry of the molding tool (3).

[0346] 14. A capacitor plate assembly for an apparatus for producing a particle foam component, in particular for producing a sole or midsole or a part thereof, said capacitor plate assembly comprising:

[0347] at least a first capacitor plate section (87) adapted to be attached to an insulator and including a terminal portion adapted to be connected to a radiation source (18) to generate electromagnetic radiation; and

[0348] one or more second capacitor plate segments (85);

[0349] The first capacitor plate section (87) and the second capacitor plate section (85) are designed to jointly form a capacitor plate (15), the surface area of ​​which can be adapted to the dimensions of a molding tool (3) for producing the particle foam component.

[0350] 15. The capacitor plate set of example 14, wherein the one or more capacitor plate segments (85, 86) are detachably electrically and mechanically connected to each other to collectively form the capacitor plates (15, 16).

[0351] 16. A capacitor plate group according to Example 14, wherein the one or more second capacitor plate segments (85) each include a terminal area for connecting to a radiation source (18) to generate electromagnetic radiation, and each capacitor plate segment (85, 87) is designed so that it is electrically insulated from other capacitor plate segments (85, 87) in the capacitor plate (15) formed by it and can be connected or disconnected by an adjustable resonant circuit (40).

[0352] 17. The capacitor plate group of any one of Examples 14 to 16, wherein the capacitor plate group is suitable for use in a device of any one of Examples 1 to 13.

[0353] 18. A method for producing a particle foam component, in particular a sole or midsole or a part thereof, comprising the following steps:

[0354] a. Filling the foam particles (29) into the cavity (14) of the molding tool (3), wherein at least two capacitor plates (15, 16) are arranged adjacent to the cavity (14), which are electrically connected to a radiation source (18) for electromagnetic radiation to generate electromagnetic radiation;

[0355] b. fusing the foam particles (29) by electromagnetic radiation between the capacitor plates (15, 16); and

[0356] c. demoulding the particle foam component; wherein

[0357] d. At least one of the two capacitor plates (15, 16) is formed from a plurality of segments (85, 86), wherein the area of ​​the capacitor plates (15, 16) is adapted to the dimensions of the molding tool (3) by combining the radiation generating segments (85, 86).

[0358] 19. A method according to Example 18, wherein the segments (85, 86) are detachably electrically and mechanically connected to each other to combine them.

[0359] 20. A method according to Example 18, wherein the segments (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 segments (85, 86) to combine them with each other.

[0360] 21. The method of example 20, wherein voltages applied to separate pairs of zones (85, 86) are measured separately, and power supplied to the corresponding pair of zones (85, 86) is adjusted separately based on the measured voltages.

[0361] 22. The method of any one of Examples 18 to 20, wherein the device of any one of Examples 1 to 14 and / or the capacitor plate group of any one of Examples 15 to 17 are used.

Claims

1. A device (1) for producing a sole or a part of a sole from foam particles (29), wherein: The device comprises: a. a molding tool (3) formed of at least two mold halves (12, 13) defining a mold cavity (14); b. at least two capacitor plates (15, 16) 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 (86) at an adaptable distance (d) from the cavity; c. An electrically conductive connecting element that electrically connects two or more segments at their edges.

2. The device according to claim 1, wherein: The segments are electrically connected to a conductive electrode body (100).

3. The device according to claim 2, wherein: The electrode body is at ground potential.

4. The device according to any one of claims 1 to 3, wherein: The capacitor plate connected to the radiation source is a first capacitor plate on one side of the cavity, and the capacitor plate in which the several sections having an adaptable distance from the cavity are included is a second capacitor plate on the opposite side of the cavity.

5. The device according to any one of claims 1 to 3, wherein: The distance of the segments to the cavity can be adjusted individually by means of mechanical and / or electrical actuator means.

6. The device according to any one of claims 1, wherein: The segments are arranged in a two-dimensional grid (130).

7. The device according to claim 6, wherein: The two-dimensional grid is a rectangular grid.

8. The device according to claim 6 or 7, wherein: The grid density varies locally.

9. The device according to claim 2, wherein: The segments are configured as screws or pins which are adjustably connected to the electrode body.

10. The device according to claim 9, wherein: The screw is a metal screw which is screwed into the electrode body, and wherein the electrode body is made of or comprises metal.

11. The device according to claim 9 or 10, further comprising a cover plate (110) of a non-conductive material, the cover plate being arranged on the electrode body and comprising an opening, the screw or pin being arranged in the opening.

12. The device according to claim 11, wherein: The cover plate is made of or comprises an electrically insulating cover.

13. The device according to claim 12, wherein: The cover plate is made of or includes one or more of the following materials: polytetrafluoroethylene (PTFE); polyethylene (PE); polyetherketone (PEEK); thermoplastic plastic; thermosetting plastic; polyethylene terephthalate (PET); polyoxymethylene (POM); polystyrene (PS); insulating mineral material.

14. The device of claim 13, wherein the polyethylene is ultra high molecular weight polyethylene (UHMWPE).

15. The device according to any one of the preceding claims 1 to 3, wherein: Each of the segments can be set to at least one of the following four positions: removed (86x) or electrically disconnected, a low position (861), a middle position (86m), a high position (86h).

16. The device according to any one of the preceding claims 1 to 3, wherein: When the cavity is irradiated with electromagnetic radiation, the position of the segments can be adjusted.

17. The device according to any one of the preceding claims 1 to 3, wherein: Adjusting the position of one or more of the segments affects the field strength distribution of the radiated electromagnetic field within the cavity.

18. The device according to any one of the preceding claims 1 to 3, wherein: The shape of the capacitor plate connected to the radiation source is at least partially adapted to the geometry of the component to be manufactured.

19. A method for manufacturing a shoe sole or a part of a shoe sole from foam particles (29), the method comprising: a. loading the particles into a cavity (14) of a molding tool (3), the molding tool being formed by at least two mold halves (12, 13) defining the cavity, wherein at least two capacitor plates (15, 16) 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 segments (86) at an adaptable distance (d) from the cavity, wherein an electrically conductive connecting element electrically connects two or more segments at their edges; b. irradiating the cavity with electromagnetic radiation emitted by the capacitor plates; and c. locally adjusting the field intensity distribution of the irradiating electromagnetic field within the cavity by changing the adaptable distance from the segment to the cavity.

20. The method according to claim 19, wherein: The alteration occurs before and / or during irradiation of the cavity with the electromagnetic radiation.

21. The method according to claim 19 or 20, wherein: The foam particles contain one or more of the following base materials: thermoplastic polyurethane (TPU); polylactic acid ester (PLA); polyamide (PA); polyether block amide (PEBA); polyethylene terephthalate (PET); polybutylene terephthalate (PBT); thermoplastic polyester ether elastomer (TPEE).

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