DE102019127708A1 - Method and device for sorting and / or measuring the amount of foam particles - Google Patents

Abstract

The invention relates to a device and a method for sorting foam particles and / or measuring the amount of foam particles. Here, the foam particles are scanned by means of an optical sensor and their quality is automatically assessed and / or the individual foam particles are counted. Foam particles which do not meet the predetermined quality criterion are discharged and / or the amount of foam particles is apportioned on the basis of the counted number of foam particles.

Description

The present invention relates to a method and a device for sorting foam particles and / or measuring the amount of foam particles. The present invention further relates to a foaming device or a device for producing particle foam parts, which are combined with a device for sorting foam particles and / or measuring the amount of foam particles.

Particle foam parts are produced by welding foam particles together. Corresponding devices and methods have been in industrial use for decades. Such particle foam parts are used, among other things, as packaging material. Foam particles made of expandable thermoplastic polystyrene (ePS) are mainly used for this. Particle foam parts are also produced on a large scale from foam particles made of expandable thermoplastic polypropylene (ePP).

Particle foam parts are primarily mass-produced items that are manufactured in large numbers at a low unit price. A typical application is, for example, thermal insulation panels for buildings.

Particle foam parts are also increasingly being used as technical, in particular mechanical, functional parts. For example, it is known to manufacture the midsoles of shoes from particle foam parts made of expanded thermoplastic polyurethane (ETPU). These particle foam parts are characterized by certain mechanical (in the case of shoes: elastic) properties.

Furthermore, sorting machines are known from other branches of industry with which small-sized goods, in particular small-sized foodstuffs, can be automatically measured and sorted. Such sorting machines go, for example, from the U.S. 5,538,142 , the DE 40 29 202 A1 , the EP 2 191 264 B1 and the EP 2 382 059 B1 emerged.

From the WO 2012/143692 A2 a process emerges with which partially contaminated small-sized material can be sorted. A heat treatment is carried out here. Due to the heat treatment, the contaminated material changes its color. The contaminated material is thus visually distinguishable from the non-contaminated material and can be sorted out accordingly. This method is also suitable for plastic materials, especially recycled plastic materials.

From the catalogue “Optical technologies for image processing”, 2019/2020 by Opto Engineering Srl, Italy, are from pages 78 to 79 catadioptric lenses are known, which are ring-shaped lenses for 306 ° imaging of small objects.

The invention is based on the object of creating a method and a device for sorting foam particles and / or measuring the amount of foam particles in order to be able to produce high quality particle foam parts.

The object is achieved by the subjects of the independent claims. Advantageous refinements are specified in the respective subclaims.

• - optisches Abtasten von Schaumstoffpartikeln mittels eines optischen Sensors,
• - automatisches Bewerten der Qualität der einzelnen Schaumstoffpartikel nach einem vorbestimmten Qualitätskriterium und/oder automatisches Zählen der Schaumstoffpartikel, und
• - Ausschleusen von Schaumstoffpartikeln, welche dem vorbestimmten Qualitätskriterium nicht genügen, und/oder Portionieren der Menge der Schaumstoffpartikel anhand der gezählten Anzahl von Schaumstoffpartikeln.

A method according to the invention for sorting foam particles and / or measuring the amount of foam particles comprises the following steps:

• - optical scanning of foam particles by means of an optical sensor,
• - automatic evaluation of the quality of the individual foam particles according to a predetermined quality criterion and / or automatic counting of the foam particles, and
• - Removal of foam particles that do not meet the predetermined quality criterion, and / or portioning the amount of foam particles on the basis of the counted number of foam particles.

The inventors of the present invention have recognized that the quality of particle foam parts which are produced from foam particles, the quality of which is automatically monitored and controlled and / or the quantity of which is automatically determined, can be increased considerably. On the one hand, when producing particle foam parts there is often the problem that foam particles are not sufficiently foamed before they are fed to the molding tool for welding. Such foam particles are small and wrinkled and comparatively hard. They lead to defects in the finished particle foam part. By sorting out such insufficiently foamed foam particles, the quality of a particle foam part can be significantly improved. On the other hand, it is possible to produce particle foam parts with significantly better mechanical properties compared to conventional particle foam parts if the size distribution of the individual foam particles and / or the moisture content and / or the surface quality is checked and maintained within predetermined ranges before welding. For example, the elasticity depends and / or Rigidity also depends on the size of the welded foam particles. The envelope or skin of the individual foam particles forms a three-dimensional network in the finished particle foam part, which stabilizes the particle foam part. Each foam particle forms a cell in this network. The cell size has a significant influence on the mechanical properties of the particle foam part produced in this way. This can be ensured by measuring and sorting the foam particles before welding.

Another problem that exists in the production of particle foam parts is that individual foam particles of the particle foam part are discolored. Such particle foam parts form a reject. During the production of the foam particles and during the preparation, in particular the foaming of the foam particles, individual particles can become discolored. These discolored foam particles are captured and discharged.

By measuring and sorting it is possible to produce particle foam parts with certain, defined quality properties. This enables the use of particle foam parts not only in the well-known mass products for packaging and insulation boards, in which the quality of the welding of the individual foam particles is rather low, but also the use of particle foam parts in technically demanding applications in which the particle foam parts have certain mechanical properties Applications must meet. In addition, the long-known advantages of the particle foam part are retained, which are primarily the low weight of the particle foam parts and the cost-effective production.

The optical monitoring and sorting out or automatic determination of the amount of foam particles before welding them together to form a particle foam part thus leads to a considerable leap in quality in the particle foam parts produced in this way.

By determining the amount of foam particles, it is possible, when filling a cracking gap tool, to open the cracking gap less than would be necessary if the amount of foam particles were not measured so precisely. A smaller crack gap during filling also means that less steam escapes from the crack gap, which means that steam loss and energy consumption are lower.

Before the optical scanning, the foam particles are preferably separated so that essentially each foam particle is optically scanned separately. In this way, very precise monitoring of the individual foam particles is achieved.

In principle, however, it is also possible to optically scan several foam particles at once and evaluate them together without isolation, whereby individual foam particles can also be covered by other foam particles, so that not all foam particles are scanned. Such statistical scanning can make sense in order to determine how high the proportion of foam particles that do not meet the predetermined quality requirements is. With such a scan, the evaluation of the quality of the foam particles cannot be assigned to an individual foam particle but only to a stream of foam particles. This is then to be ejected in its entirety if it does not meet the desired quality requirements.

However, it is also possible to separate the foam particles so strongly before the optical scanning that each foam particle is scanned and analyzed separately, so that it can be decided individually for each foam particle whether it is to be ejected.

• - Brechen von Klumpen von Schaumstoffpartikeln mittels einer Zellradschleuse und/oder Förderschnecke,
• - Rühren der Schaumstoffpartikel mit einem Rührer,
• - Rütteln der Schaumstoffpartikel mit einem Rüttler,
• - Bewegen der Schaumstoffpartikel mit einer Luftströmung, welche als Fluidisierluft bezeichnet wird, und/oder
• - Zuführen zu einem Abtastbereich auf einer schräg verlaufenden Schütte.

The separation of the foam particles can be carried out with one or more of the following steps:

• - Breaking lumps of foam particles by means of a rotary valve and / or a screw conveyor,
• - stirring the foam particles with a stirrer,
• - shaking the foam particles with a vibrator,
• - Moving the foam particles with an air flow, which is referred to as fluidizing air, and / or
• - Feeding to a scanning area on an inclined chute.

The individual steps for separating the foam particles can be carried out individually or in combination in any order. It can also be useful to carry out certain steps at the same time, such as vibrating the foam particles with a vibrator and moving the foam particles with fluidizing air. The feeding to a scanning area on an inclined chute is preferably the last step in the isolation of the foam particles, since several foam particles are optically scanned on the chute at the same time.

Such a chute is for example from the DE 40 29 202 A1 known.

The sorting device can also have several discharge stations in which foam particles are discharged according to different criteria. This allows the foam particles to be sorted into different classes. The discharged foam particles do not necessarily have to be of poor quality. If the foam particles are sorted by color, for example, foam particles of one color may be preferred for certain applications and foam particles of the other color may be preferred for other applications. With a multi-stage discharge, foam particles of different quality can be sorted and then later processed accordingly.

The foam particles can be transported through lines at least in some areas. Preferably, liquid or vaporous water is added to the foam particles during transport through such lines. As a result, the foam particles are wetted on their surface, which counteracts clumping. When using water in vapor form, the foam particles can be activated in a targeted manner because they are heated by the steam. Activation of foam particles is understood to mean, on the one hand, the foaming of the foam particles, since the air or a propellant contained therein expands under the action of heat, and on the other hand, the softening or melting of the surface of the foam particles. However, the supply of steam is controlled in such a way that the foam particles are not melted in such a way that they bond with one another during transport. The steam is therefore preferably metered in such that the surface of the foam particles only becomes so soft immediately before entering a molding tool that the foam particles only weld together in the molding tool. By supplying heat by means of steam in the mold space, foaming of the foam particles should be effected and their surface should be made soft so that they combine in the mold space to form a particle foam part.

In such lines, the foam particles are preferably blown at least by means of propellant air or sucked in by means of negative pressure.

When the foam particles are optically scanned, the brightness and / or the color and / or the shape of the foam particles can be detected.

During the optical scanning, the foam particles can be irradiated with visible light and / or infrared light and / or light which generates luminescence. It is also possible to use a very broadband light source, such as a halogen light source, for example with a spectrum of, for example, 400 nm to 1000 nm, with one or more color filters being assigned to the sensors so that the individual sensors are only used for certain color ranges are specific. These color filters can also already be integrated in a camera, for example in an RGB camera, in which each sensor point is assigned a separate color filter in one of the three colors red, green or blue. Color-specific sensor values can be determined by reading out the individual points. It is also possible, by means of one or more beam splitters, to supply the light reflected by the foam particles to several sensors at the same time, which sensors are sensitive to different spectra.

The foam particles can also be irradiated simultaneously with light from two different light sources, each with a different spectrum. One or both light sources preferably emit light with a narrow bandwidth of a few 10 nm to a maximum of 200 nm. As a result, a certain property of the foam particles, the reflection property of which is specific for this spectrum as a function of the state of this property, can be scanned.

• - Optisches Abtasten der Helligkeit und/oder der Farbe des jeweiligen Schaumstoffpartikels, wobei Schaumstoffpartikel mit einer vorbestimmten Helligkeit und/oder mit einer Farbe, welche innerhalb eines vorbestimmten Farbbereichs liegt, als dem Qualitätskriterium genügend beurteilt werden, wobei hiermit die Glattheit und/oder die Oberflächenbeschaffenheit und/oder der Feuchtezustand der Schaumstoffpartikel und/oder die Art des Schaumstoffpartikels bei einem Gemisch unterschiedlicher Schaumstoffpartikel beurteilt werden.
• - Bestimmen der Anzahl der Schaumstoffpartikel, wobei als Qualitätskriterium eine vorbestimmte Mindestanzahl und/oder eine vorbestimmte Maximalanzahl verwendet werden. Zum Bestimmen der Anzahl der Schaumstoffpartikel können unterschiedliche optische Eigenschaften verwendet werden. Typischerweise wird eine optische Eigenschaft (Farbe, Helligkeit, etc.) verwendet, welche sich vom Hintergrund unterscheidet, um die Partikel zu detektieren. Die Partikel können auch mittels einer Lichtschranke detektiert werden, welche als optische Eigenschaft die Lichtundurchlässigkeit der Partikel verwendet.
• - Bestimmen der Schaumstoffpartikel mittels einer Objekterkennung, wobei die Größe und/oder die Form der Schaumstoffpartikel beurteilt werden kann, und Schaumstoffpartikel, welche eine vorbestimmte Mindestgröße und/oder welche eine vorbestimmte Maximalgröße aufweisen, als dem Qualitätskriterium genügend beurteilt werden, und /oder Schaumstoffpartikel, welche von einer Kugelform um ein bestimmtes Maß abweichen als dem Qualitätskriterium genügend oder nicht genügend beurteilt werden. Verfahren zur Objekterkennung sind an sich bekannt. Sie verwenden unterschiedliche optische Eigenschaften, insbesondere welche, die sich vom Hintergrund unterscheiden. Es können auch mehrere optische Eigenschaften in Kombination verwendet werden, um die einzelnen Objekte zu klassifizieren.
• - Abtasten der Schaumstoffpartikel mittels einer Strahlung, welche Fotolumineszenz an den Schaumstoffpartikeln bewirkt, und Messen der Intensität des Lichtes der einzelnen Schaumstoffpartikel, wobei die Intensität des Lichtes etwa proportional zur Größe der einzelnen Schaumstoffpartikel ist und Beurteilen der Größe der Schaumstoffpartikel anhand der Intensität dahingehend, ob die Schaumstoffpartikel eine vorbestimmte Mindestgröße und/oder eine vorbestimmte Maximalgröße aufweisen, um dem Qualitätskriterium zu genügen.
• - Abtasten der Schaumstoffpartikel mittels Infrarotlicht und Bestimmen der Helligkeit und/oder Farbe der mit Infrarotlicht bestrahlten Schaumstoffpartikel, wobei der Feuchtezustand der Schaumstoffpartikel etwa umgekehrt proportional zur Helligkeit der mit Infrarotlicht bestrahlten Schaumstoffpartikel ist oder etwa proportional zu einer vorbestimmten Farbskala ist.

The foam particles can be optically scanned according to a predetermined property of the foam particles in order to check whether the foam particles meet a certain quality criterion. These optical properties and the corresponding quality criteria are, for example:

• Optical scanning of the brightness and / or the color of the respective foam particle, whereby foam particles with a predetermined brightness and / or with a color which lies within a predetermined color range are assessed as sufficient for the quality criterion, with the smoothness and / or the surface texture and / or the moisture status of the foam particles and / or the type of foam particle can be assessed in the case of a mixture of different foam particles.
• - Determination of the number of foam particles, a predetermined minimum number and / or a predetermined maximum number being used as the quality criterion. Different optical properties can be used to determine the number of foam particles. Typically will uses an optical property (color, brightness, etc.) that differs from the background to detect the particles. The particles can also be detected by means of a light barrier, which uses the opacity of the particles as an optical property.
• - Determination of the foam particles by means of object recognition, wherein the size and / or the shape of the foam particles can be assessed, and foam particles which have a predetermined minimum size and / or which have a predetermined maximum size are assessed as being sufficient for the quality criterion and / or foam particles, which deviate from a spherical shape by a certain amount are judged to be sufficient or insufficient for the quality criterion. Methods for object recognition are known per se. They use different optical properties, especially those that differ from the background. Several optical properties can also be used in combination to classify the individual objects.
• - Scanning the foam particles by means of radiation, which causes photoluminescence on the foam particles, and measuring the intensity of the light of the individual foam particles, the intensity of the light being roughly proportional to the size of the individual foam particles and assessing the size of the foam particles based on the intensity to determine whether the foam particles have a predetermined minimum size and / or a predetermined maximum size in order to meet the quality criterion.
• - Scanning the foam particles by means of infrared light and determining the brightness and / or color of the foam particles irradiated with infrared light, the moisture state of the foam particles being approximately inversely proportional to the brightness of the foam particles irradiated with infrared light or being approximately proportional to a predetermined color scale.

By scanning the brightness and / or the color, conclusions can be drawn about the smoothness and / or the surface properties and / or the moisture status of the foam particles and / or the type of foam particles. When mixing different foam particles, the mixing ratio of the different foam particles can be determined and, if necessary, corrected on the basis of the brightness and / or color. The roughness of the surface can also be recognized optically on the basis of the brightness and / or color.

By means of object recognition, the individual foam particles can be analyzed with regard to their size and shape. This makes it possible to sort out foam particles whose shape and / or size do not correspond to predetermined quality requirements.

The foam particles can also be scanned simultaneously with at least two or more sensors or cameras from different directions. This can ensure that the complete shape of the foam particles is recognized. There are z. B. foam particles known which are elongated. If they are viewed from one face with only one camera, then they are shown in a circle. From this one could conclude that the foam particles are spherical, although they have an elongated, cigar-like shape.

Instead of several sensors or cameras, a camera with a catadioptric object can also be used. Catadioptric lenses are ring-shaped lenses that allow 360 ° scanning of an object that is located inside the ring-shaped lens. Such catadioptric objectives are offered, for example, by Opto Engineering S.r.l., Italy. Such a catadioptric objective is arranged in the sorting device in such a way that the trajectory of the isolated foam particles extends through the annular objective. As a result, a complete scanning of the surface and the shape of each foam particle can be carried out by means of a single camera.

For scanning foam particles which deviate from the spherical shape, it can also be expedient to align them before the optical scanning so that they can be moved with a defined position along the field of view of the camera. This can be done, for example, by moving the foam particles on a conveyor belt along the field of view of the camera, whereby they are aligned on the conveyor belt by means of a guide device, such as a broom or baffle plate, before scanning.

By irradiating the foam particles with special light sources which, for example, cause photoluminescence on the foam particles or emit infrared light, certain properties of the foam particles can be recorded in a targeted manner. It has been shown that irradiation by means of infrared light is particularly suitable for detecting the moisture status of the foam particles. A moist foam particle reflects infrared light much more strongly than a dry foam particle. Therefore, a moist foam particle that is irradiated with infrared light is in the pictorial representation much lighter than a dry foam particle. The foam particles can be scanned by means of infrared light by irradiation with a corresponding light source and / or by means of an infrared camera. If an infrared light source and an infrared camera are used, then a very high sensitivity is achieved. However, it has been shown that when the foam particle is irradiated by means of infrared light and a commercially available camera is used, it is sufficient, since this is usually sufficiently sensitive in the infrared range to detect the reflected infrared light. Daylight or a broadband light source can equally be used to scan the foam particles by means of an infrared camera. With the last two measuring systems with either an infrared light source or an infrared camera, the sensitivity is slightly lower than when using both an infrared light source and an infrared camera, but this is still usually sufficient to reliably scan the foam particles in the infrared range.

Certain foam particles are preferably discharged by means of a controlled air jet in order to deflect the movement of individual foam particles in a controlled manner. This is for example from the U.S. 5,538,142 known. On the other hand, the discharge can also take place by means of pivotable flaps, which deflect the movement path of individual foam particles. Such a discharge device is, for example, from DE 40 29 202 A1 known.

To portion a predetermined amount of foam particles, these can be introduced into a lock chamber of a lock, the supply of the particles to the lock chamber being controlled as a function of the counted particle foam parts. If the lock contains the predetermined number of foam particles, then this portion of foam particles is fed to a molding tool. This ensures that the same amount or the same number of foam particles is always welded to form a particle foam part. Such a lock can have one or more lock chambers. A plurality of lock chambers are preferably provided so that a flow of foam particles can be continuously fed to the lock and, when one lock chamber is completely filled, the flow is merely diverted to another lock chamber.

• - Bei einer Überfüllung werden die Formhälften des Werkzeuges ein Stück auseinandergefahren und/oder der Füllluftdruck an einem Füllinjektor, der Druck in einer Zuführleitung und/oder der Druck in einem Materialbehälter, aus dem die Schaumstoffpartikel abgezogen werden, erhöht, um alle Schaumstoffpartikel im Formwerkzeug aufzunehmen, und/oder ein Füllinjektor mit einer Nachdrückfunktion verwendet, mit welchem Schaumstoffpartikel in das Formwerkzeug gedrückt werden, und/oder
• - bei einer Unter- oder Überfüllung wird im nachfolgenden Füllvorgang eine entsprechend größere oder kleinere Menge an Schaumstoffpartikeln abgemessen.

Such a measured amount of foam particles can be fed to a molding tool which has two mold halves, the filling state on the molding tool being detected by means of a sensor. The sensor is therefore preferably arranged in such a way that it detects the foam particles in the area of a filling opening of the molding tool. If the sensor detects a filling level that deviates from a target filling level, then one or more of the following steps are carried out:

• - In the event of overfilling, the mold halves of the tool are moved apart a little and / or the filling air pressure on a filling injector, the pressure in a feed line and / or the pressure in a material container from which the foam particles are withdrawn is increased in order to accommodate all the foam particles in the mold , and / or a filling injector with a hold-down function is used, with which foam particles are pressed into the mold, and / or
• - In the event of underfilling or overfilling, a correspondingly larger or smaller amount of foam particles is measured in the subsequent filling process.

The filling injector with hold-down function has a sealing piston which can be actuated in such a way that foam particles located in the filling injector can be pressed into the molding tool with the sealing piston. The sealing piston can be actuated pneumatically or electrically, for example by means of a spindle.

• - einen optischen Sensor zum optischen Abtasten von Schaumstoffpartikeln,
• - eine Steuereinrichtung zum automatischen Bewerten der Qualität der einzelnen Schaumstoffpartikel nach einem vorbestimmten Qualitätskriterium und/oder zum automatischen Zählen der Schaumstoffpartikel, und
• - eine Einrichtung zum Ausschleusen von Schaumstoffpartikeln, welche dem vorbestimmten Qualitätskriterium nicht genügen, und/oder zum Portionieren der Menge der Schaumstoffpartikel anhand der gezählten Anzahl von Schaumstoffpartikeln.

According to a further aspect of the present invention, a device for sorting foam particles and / or measuring the amount of foam particles is provided, comprising

• - an optical sensor for the optical scanning of foam particles,
• a control device for automatically evaluating the quality of the individual foam particles according to a predetermined quality criterion and / or for automatically counting the foam particles, and
• a device for discharging foam particles which do not meet the predetermined quality criterion and / or for portioning the amount of foam particles on the basis of the counted number of foam particles.

With this device, a selection of the foam particles is produced, whereby particle foam parts can be produced with high quality, as explained in detail above. The scrap can be reduced significantly. Particle foam parts are mass products. A reduction in rejects means considerable cost savings.

The quality criterion according to which the foam particles are evaluated can also be a combination of several quality criteria which are applied simultaneously.

This device can be combined with a separating device which is arranged upstream of the optical sensor in the direction of flow. The separating device can, for example, have an inclined chute on which the foam particles can slide down. The separating device can, however, also be a continuous air flow that blows transversely to the direction of flow of the foam particles, whereby the foam particles can be separated and sorted according to their density at the same time. Large, low-density foam particles deflect more than small, high-density foam particles. This allows a rough preliminary sorting to be carried out, in which case, in particular, small, heavy foam particles which are not sufficiently foamed can be sorted out. At the same time, the individual foam particles can be separated from one another by such an air jet, so that they can be caught by means of a funnel and passed on in a narrow chute through which only individual foam particles can fit.

The foam particles can be fed to the separating device by means of a screw conveyor or conveyor spindle, so that a continuously defined amount of foam particles can be separated and / or sorted.

According to a further aspect of the present invention, a foaming device for pre-foaming foam particles is provided. This foaming device has a foaming container in which heat is supplied to pre-foaming foam particles. This heat can be supplied by means of steam, infrared radiation and / or electromagnetic waves such as RF radiation or microwaves. This foaming device is followed by such a device for sorting foam particles and / or measuring the amount of foam particles. This makes it possible to monitor the quality of the pre-expanded foam particles and to sort them accordingly. In addition, by monitoring the quality of the pre-expanded foam particles, the amount of heat supplied in the foam container can be automatically controlled so that the foaming device can be operated to produce foam particles with a certain size and / or certain density and the supply of heat is thereby automatically adjusted. This is particularly useful if the heat is supplied not with steam but by means of electromagnetic waves, in particular RF radiation, infrared radiation and / or microwaves, since the metering of the heat supply by means of electromagnetic waves is often difficult without such feedback. This represents an independent concept of the invention, which can also be carried out without sorting or measuring the amount of foam particles.

The electromagnetic waves are preferably electromagnetic RF radiation. 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 and preferably at least 10 MHz.

The electromagnetic RF radiation preferably has a frequency of at most 300 MHz.

The electromagnetic waves can also be microwaves in the frequency range from 300 MHz to 300 GHz.

The mean size of the pre-expanded foam particles can be determined, for example, by means of a volumetric metering system. The volumetric dosing system can be combined with a scale to determine the average density of the foam particles.

According to a further aspect of the present invention, a device for producing particle foam parts with a molding tool is provided which has a heating device for welding foam particles within a mold cavity of the molding tool to form a particle foam part. This device is combined with a device for sorting foam particles and / or measuring the amount of foam particles which is arranged upstream of the molding tool in the direction of flow.

The molding tool is preferably arranged horizontally. This ensures that the foam particles are evenly distributed in the mold cavity of the mold. If the molding tool is arranged vertically, there is the risk that the foam particles will collect with a higher density than in the upper area, especially in the lower area of the mold cavity, and are therefore not evenly distributed.

• 1 schematisch eine Vorrichtung zum Sortieren von Schaumstoffpartikel während des Transportes von einem Vorratsbehälter zu einem Formwerkzeug,
• 2 schematisch eine zweistufige Sortiereinrichtung für Schaumstoffpartikel,
• 3 schematisch eine Vorrichtung zum Herstellen von Partikelschaumstoffteilen mit mehreren Formwerkzeugen und einer Sortiervorrichtung, und
• 4a - 4c eine Zähleinrichtung und einen Füllinjektor mit Nachdrückfunktion in einer seitlichen Schnittansicht.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. The drawings show in:

• 1 schematically a device for sorting foam particles during transport from a storage container to a molding tool,
• 2 schematically a two-stage sorting device for foam particles,
• 3 schematically a device for producing particle foam parts with several molding tools and a sorting device, and
• 4a - 4c a counting device and a filling injector with hold-down function in a side sectional view.

A first embodiment of a device 1 for sorting foam particles 2 is in a device for producing a particle foam part in the area between a storage container 3 and a molding tool 4th arranged.

The reservoir 3 serves to hold pre-expanded foam particles 2 , which in the storage container 3 can be kept under pressure or without pressure.

The reservoir 3 is on a screw conveyor 5 coupled. The screw conveyor 5 has a delivery pipe 6th on, in which a snail 7th rotatable and powered by a motor 8th powered bearings.

The screw conveyor 5 fulfills two functions, that of transporting the foam particles 2 from the storage container 3 to a delivery line 9 and that of breaking up foam particles that are bound into lumps 2 . With the screw conveyor 5 the foam particles are separated on the one hand and on the other hand continuously along the conveying line 9 fed.

To the delivery line 9 is adjacent to the screw conveyor 5 a compressed air line 10 by means of a feed nozzle 11 connected. The compressed air line 10 leads from a source of compressed air 12th to the delivery line 9 .

The compressed air supplied here is used to transport the foam particles 2 within the compressed air line 10 .

The delivery line 9 ends running horizontally in the sorting device 1 so that the individual foam particles 2 from the delivery line 9 ejected in the horizontal direction.

Provided the movement of the foam particles 2 is not disturbed, they fly along a parabola to a collecting funnel 13th located inside the sorting device 1 is located. The collecting funnel 13th is connected to a second section of the delivery line 9 connected. At this second section of the delivery line 9 in turn opens the compressed air line 10 with a feed nozzle 14th to remove from the collecting funnel 13th captured foam particles through the second section of the compressed air line 10 to transport. The second section of the delivery line 9 leads to a filling injector 15th which is attached to the molding tool 4th is coupled. The molding tool 4th consists of two mold halves 16 , 17th . The filling injector 15th is with the compressed air line 10 connected, with which in the area of the filling injector 15th located foam particles in the mold 4th to get promoted.

The sorting device 1 has several optical sensors 18th to 20th on to the foam particles 2 on their parabolic flight from the delivery line 9 to the collecting funnel 13th to be scanned at predetermined points.

In the present exemplary embodiment, the optical sensors are 18th to 20th each designed as a camera, the camera 18th a color camera and the cameras 19th and 20th each are grayscale cameras. A first lighting device 21 is designed to emit a directed light beam cone which is directed to the point of the trajectory of the foam particles at which the foam particles from the camera 18th are recorded. The first lighting device 21 is on the same side as the camera in terms of trajectory 18th arranged. This allows the camera to see 18th the light of the first lighting device reflected by the respective foam particles 21 . The first lighting device is a light source with a broad spectrum of light. The light spectrum can include visible light, infrared light and / or ultraviolet light. The frequency range of the camera 18th , in which the light is detected, is designed so that it is at least partially with the frequency range of the first lighting device 21 matches.

A second lighting device 22nd is arranged in such a way that it directs a bundled light beam cone onto another point of the trajectory of the foam particles, at which the foam particles from the second camera 19th are scanned. The second lighting device 22nd can be designed to emit monochromatic light or light with a predetermined spectral range. The second camera 19th and the second lighting device 22nd are in turn arranged on the same side with respect to the trajectory of the foam particles, so that the second camera 19th from the second lighting device 22nd light emitted and reflected by one of the foam particles is detected.

The third camera 20th is facing the same point on the flight path as the second camera 19th directed. However, with regard to the trajectory of the foam particles, it is located on the other side diametrically opposite the second lighting device 22nd . The light of the second lighting device is thus generated with the third camera 22nd detected when there are no foam particles on the connecting line between the second lighting device 22nd and the third camera 20th is located. Otherwise, the light of the second lighting device 22nd regarding the third camera 20th shaded by a foam particle. With the third camera 20th it can thus be detected very reliably whether a foam particle is located within the scanning area. This arrangement, which is also referred to as a transmitted light arrangement, is particularly suitable for detecting whether a foam particle is present or not. It is therefore primarily used to count the individual foam particles that fly along the flight path.

A discharge nozzle 23 is adjacent to the trajectory of the foam particles and in the direction of movement of the foam particles after the scanning areas of the optical sensors 19th to 20th arranged. The discharge nozzle 23 is to the compressed air line 10 connected. The discharge nozzle 23 has a nozzle opening which is directed in the direction of the movement path of the foam particles. The discharge nozzle 23 is connected to a central control device (not shown), with which one from the discharge nozzle 23 escaping airflow can be switched on and off in a targeted manner. With this air flow, individual foam particles can move from the parabolic trajectory in the direction of a collecting container 24 get distracted. These deflected foam particles then fly into the collecting container 24 and are collected there. The discharge nozzle 23 thus serves to discharge individual foam particles from the parabolic movement of the conveying line 9 to the collecting funnel 13th .

During operation, the foam particles are removed from the storage container 3 conveyed to the molding tool, where they are on their transport path within the sorting device along the parabolic trajectory of the cameras 18th to 20th are scanned. The cameras 18th to 20th are connected to a central control device (not shown). The optical signals are evaluated on this. The evaluation takes place according to predetermined quality criteria and / or can simply be a simple counting of the individual foam particles.

If a certain foam particle does not meet the desired quality criterion, it is removed by means of the discharge nozzle 23 discharged and into the collecting container 24 distracted.

The promotion of the foam particles 2 can be interrupted when a sufficient number of foam particles are already in the mold 4th was fed. This is done, for example, by stopping the supply of compressed air to the first section of the delivery line 9 accomplished. Thus, a molding tool 4th exactly the desired number of foam particles 2 are fed.

A precise measurement of the amount of foam particles increases the quality of the particle foam parts produced in this way and reduces rejects.

Furthermore, particles with a discoloration and / or insufficiently expanded particles can be sorted out automatically. This also leads to a considerable increase in the quality of the particle foam parts. In the case of certain products, a particle foam part is already considered to be scrap if a single particle on the surface of the particle foam part is discolored or if one or more particles have not expanded sufficiently at any point on the particle foam part, thus interrupting the uniform structure of the particle foam part.

In the exemplary embodiment explained above, the foam particles are scanned and rejected while they are moving on a parabolic trajectory. However, the sorting device can also be designed differently. The second embodiment is a two-stage sorting device 1 with a first sorting level 25th and a second sorting stage 26th ( 2 ). The sorting device 1 is in the area between a first section of a delivery line 9 and a second section of the delivery line 9 on which the foam particles are attached by means of a collecting funnel 13th are included, arranged. The first section of the delivery line 9 can be connected to a storage container (not shown) from which the foam particles are drawn off. The second section of the delivery line 9 leads to the molding tool 4th (not shown).

The first section of the conveying line can also be connected to a foaming device with which the foam particles are pre-foamed before they are fed to a storage container from which they are withdrawn for feeding a molding tool.

The first sorting stage 25th shows a chute 27 on. The chute 27 is made of a flat, elongated plate 28 formed, which on two opposite longitudinal side edges 32 , 33 each narrow boundary walls 29 having. The chute 27 has two narrow side edges 30th , 31 on. The chute 27 is inclined so that one of the two narrow side edges is an upper narrow side edge 30th and the other narrow side edge is a lower narrow side edge 31 forms.

The chute 27 is also inclined transversely to its longitudinal direction, so that one of the two longitudinal side edges 32 below the other long side edge 33 is arranged.

Adjacent to the upper narrow side edge 30th is a mounting plate 34 provided which is flush with the plate 28 the chute 27 connects and for receiving the from the delivery line 9 exiting foam particles and for transferring to the plate 28 the chute serves. On the mounting plate 34 is a baffle 35 provided that the foam particles in the direction of the lower longitudinal side edge 32 directs.

On the upper section of the lower long side edge 32 is a cross-flow nozzle 36 arranged, which with a compressed air line 10 connected is. The cross-flow nozzle 36 is arranged so that there is an air flow along the chute 27 across the conveying direction 37 the foam particles 2 generated.

There the chute 27 also across the conveying direction 37 is inclined, the foam particles are from this cross flow in the direction of the higher longitudinal side edge 33 distracted. The lower the density of the foam particles and the larger the body, the more they will be distracted. Heavily pre-expanded foam particles have a large body with a very low density. They are deflected much more strongly than foam particles which have been pre-expanded to a lesser extent or which are not foamed at all and form small, wrinkled plastic bodies.

On the chute 27 the foam particles are thus sorted in the transverse direction according to their density / size.

On the lower narrow side edge 31 are flaps 38 at the chute 27 formed, which by means of a corresponding actuating mechanism (not shown) between a discharge position in which the flaps with the plate 28 the chute 27 are flush and can be swiveled back and forth in a sluice-in position in which the flaps are lowered.

It's a baffle 39 provided with one edge flush with the flaps 38 in the discharge position and to a collecting container 40 leads so that ejected foam particles along the respective flap 38 and the baffle 39 into the collecting container 40 slide and be collected there.

A camera 41 is facing the chute from above 27 arranged so that the camera 41 most of the area of the chute 27 detected. The camera thus creates a large number of foam particles 2 , which is on the chute 27 are recorded at the same time. The camera 41 is with a central control device 42 connected, in which the image signals of the camera are evaluated. The image signals from the camera can be evaluated according to the various criteria explained above. Since each with a picture several foam particles 2 are recorded at the same time, they can also be assessed and analyzed at the same time.

In the area below the flaps 38 is a conveyor belt 43 arranged across the chute 27 is aligned. With the flaps folded down into the infeed position 38 the foam particles fall 2 from the chute 27 onto the conveyor belt 43 . They are then off the conveyor belt 43 promoted. In the conveying direction 44 of the conveyor belt 43 is first a second camera 45 and then a discharge nozzle 46 arranged. The discharge nozzle 46 is the same as in the first embodiment like the discharge nozzle 23 to a compressed air line 10 attached and formed to individual foam particles 2 across the conveying direction 44 into another collecting container 47 branch off. The conveyor belt 43 , the camera 45 and the discharge nozzle 46 form the second sorting stage 26th . The camera 45 is in turn to the central control device 42 coupled, which the signals of the two cameras 41 , 45 receives and accordingly the flaps 38 and the discharge nozzle 46 controls.

With the first sorting stage 25th become the foam particles 2 Sorted according to their size and fed in or out accordingly.

In the second sorting stage 26th the individual foam particles are monitored according to their color and foam particles with a different color are removed. This allows foam particles with a predetermined color to the molding tool 4th are fed. However, this does not necessarily mean that all foam particles have to be of the same color. Foam particles with predetermined different colors can also be desired, in which case those foam particles are discharged whose color deviates from the predetermined colors. For example, if you want to make a particle foam part from orange and green foam particles, you want foam particles whose colors are of the desired hue deviate, such as red or blue foam particles.

With such a two-stage sorting device 1 can use the molding tool 4th supplied foam particles are sorted according to different requirements. This allows very special particle foam parts to be produced. In particular, it is also possible to add foam particles made of different materials to the molding tool in a predetermined mixing ratio 4th to feed. The foam particles made of different materials can be distinguished on the basis of their shape and / or size and / or density and / or color. The number of foam particles of the respective type can be recorded. If the ratio of the foam particles of the different types deviates from the desired ratio, this can be corrected again by discharging individual foam particles.

This allows particle foam parts to be specifically manufactured for special technical applications. This allows completely new applications of particle foam parts. The type of foam parts that are fed to the mold can also vary over time, with the mold, for example, initially being fed more foam particles of a first type and, over time, increasingly more of the second type. As a result, the particle foam part to be produced can have a mechanical property and / or optical property that changes along a specific direction.

In the molding tool 4th the foam particles are welded to the particle foam part by supplying heat. The heat can be supplied by means of steam and / or electromagnetic waves, in particular RF radiation. The corresponding devices for this are known to the person skilled in the art and need not be explained in more detail.

The molding tool 4th can be a so-called crack gap mold, in which the two halves of the mold are initially opened a bit during filling and are only completely closed after filling. This compresses the foam particles contained therein. Since the amount of foam particles can be measured very precisely with the devices and methods explained above, it is possible to open the cracking gap less than with conventional methods. As a result, less steam and thus less energy is lost, especially when welding with steam.

The first sorting stage 25th can also be designed without a camera, so that the foam particles can only be removed by the air flow and the inclination of the chute 27 be sorted.

The first sorting stage 25th is also particularly advantageous for sorting pre-expanded foam particles which are fed to a storage container after sorting. It can be used to sort different sizes of foam particles and separate them for later processing.

A device for producing particle foam parts often has several molding tools at the same time 4th on ( 3 ), which each consist of two mold halves 16 , 17th are trained. Every molding tool 4th is assigned at least one filling injector, with which the foam particles are assigned to the respective molding tool 4th are fed. The filling injectors 15th are over lines 9 with a storage container 3 connected, from which the foam particles are withdrawn.

In this embodiment are in the area between the storage container 3 and the filling injectors 15th a sorting device 1 , an intermediate container 48 and several counters 49 intended.

The sorting device 1 can be any sorting device, such as one according to the above-mentioned embodiments, for foam particles 2 to sort according to one or more predetermined criteria and the foam particles corresponding to the criteria or criteria to the intermediate container 48 to feed.

There is also a collecting container 24 provided to accommodate foam particles that do not meet the predetermined criteria.

The intermediate container 48 is via the delivery line 9 with the individual counters 49 connected. The counters 49 are designed to count the individual foam particles. The counters 49 can be used as light barriers with one light source each 51 and an optical sensor 52 be trained.

In front of the meters in the conveying direction 49 is a switching valve each 50 arranged that the delivery line 9 in the area in front of the meter 49 can close impermeable to foam particles. The switching valves 50 are designed in such a way that they continue to let gas through in the closed state that is impermeable to foam particles.

The foam particles are in the delivery line 9 conveyed by means of a carrier gas. This carrier gas can after closing the switching valves 50 continue to flow through this to already be in the range of the respective counter 49 or des respective filling injector 15th existing foam particles in the direction of the corresponding mold 4th to transport.

The counters 49 are compared to the sorting device 1 a relatively simple, inexpensive device. In this device, the sorting function and the counting function are separate from one another. This makes it possible to use a single, central sorting device 1 the foam particles for all molding tools 4th to sort according to the desired quality criteria and the number of the respective molding tools 4th supplied foam particles individually by means of the counter 49 to measure.

Is done by means of the respective counter 49 determines that a predetermined number of foam particles 2 the counter 49 have happened then the switching valve 50 switched to the closed state, so that the further supply of foam particles is prevented. By the appropriate counter 49 Then only the carrier gas flows with which already in the area between the molding tool 4th and the respective switching valve located foam particles in the mold 4th continue to be promoted.

In the present embodiment, the sorting device is 1 with the intermediate container 48 integral part of the device for producing particle foam parts. In principle, however, it is also possible to use the sorting device 1 to be provided independently of the device for producing particle foam parts, wherein one or more movable intermediate containers can be used, which are located at the exit of the sorting device 1 can be arranged for receiving sorted foam particles, and after they are filled, can be transported to a device for producing particle foam parts, where they then serve as a storage container from which the sorted foam particles are withdrawn. This allows with a sorting device 1 several devices for the production of particle foam parts can be operated at the same time. Here, too, are preferably on the device for producing the particle foam parts in the conveying direction in front of each molding tool 4th one counter each 49 provided so that the sorted foam particles are precisely dosed to the respective mold 4th can be fed.

The counters 49 are in the simplest embodiment as light barriers with a light source 51 and an optical sensor 52 educated ( 4a - 4c ). The administration 9 has for this purpose a transparent section in the area of the light barrier 53 on.

Instead of a counter 49 Other devices can also be used to determine the number or quantity of foam particles, such as a rotary valve.

The filling injector 15th can have a sealing piston 53 have a hold-down function ( 4a - 4c ). The filling injector 15th has a tubular section 54 with which the filling injector 15th to a molding tool 4th flows out.

The sealing piston 53 is formed in such a way that it extends from an area in the tubular section 54 , which is behind a connection of the conveying line in the conveying direction 9 is on the filling injector ( 4a) to the mouth of the molding tool 4th can be moved. This removes foam particles that are in the fill injector 15th are located ( 4b) , from the sealing piston 53 in by the molding tool 4th limited mold space pressed ( 4c ). This ensures that the total number of measured foam particles is in the mold space of the mold 4th is located. Such a filling injector 15th with hold-down function ensures that the counted number of foam particles in the mold 4th got. In the 4a to 4c is a circumferential filling air nozzle 55 shown with which filling air in a manner known per se in the mouth area between the filling injector 15th and the molding tool 4th is fed.

In the embodiment explained above, each mold 4th one counter each 49 assigned. In practice there are devices for producing particle foam parts, so-called molding machines, which have up to eighteen molding tools, each molding tool being able to be filled by means of one, two or more filling injectors. Here it can be useful to assign a separate counter to each filling injector, whereby the filling of the molding tools can be controlled so that each filling injector supplies a certain number of foam particles to the molding tool or the number of other foam particles of all filling injectors of a molding tool is counted so that the Total number of foam particles fed to a mold is determined.

It can also be useful to assign a common counter to several molds, whereby the line for guiding the foam particles from the counter to the individual molds is branched and is provided with corresponding switching valves so that only one of these molds is filled with foam particles. The individual molds are thus alternately filled with foam particles, with the number of foam particles is determined exactly with the counter.

If several devices for producing particle foam parts are operated at one location, then it is advisable that one or a few sorting devices with high capacity are provided independently of the devices for producing particle foam parts and that the individual devices for producing particle foam parts are provided with one or more counters are to count the foam particles that are fed to the respective molds. With the sorting devices, the foam particles are preferably sorted according to several different criteria, so that foam particles of different quality can be fed to the devices for producing the particle foam parts.

List of reference symbols

1

Sorting device

2

Foam particles

3

Storage container

4th

Forming tool

5

Auger

6th

Delivery pipe

7th

slug

8th

engine

9

Delivery line

10

Compressed air line

11

Feed nozzle

12th

Compressed air source

13th

Collecting funnel

14th

Feed nozzle

15th

Filling injector

16

Mold half

17th

Mold half

18th

Optical sensor

19th

Optical sensor

20th

Optical sensor

21

First lighting device

22nd

Second lighting device

23

Discharge nozzle

24

Collecting container

25th

First sorting level

26th

Second sorting level

27

Chute

28

plate

29

Boundary wall

30th

Narrow side edge

31

Narrow side edge

32

Long side edge

33

Long side edge

34

Mounting plate

35

Baffle

36

Cross-flow nozzle

37

Conveying direction

38

flap

39

Baffle

40

Collecting container

41

camera

42

Central control device

43

Conveyor belt

44

Conveying direction

45

camera

46

Discharge nozzle

47

Collecting container

48

Intermediate container

49

counter

50

Switching valve

51

Light source

52

sensor

53

Sealing piston

54

Tubular section

55

Filling air nozzle

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 5538142 [0005, 0035]
• DE 4029202 A1 [0005, 0021, 0035]
• EP 2191264 B1 [0005]
• EP 2382059 B1 [0005]
• WO 2012/143692 A2 [0006]

Non-patent literature cited

• "Optical technologies for image processing", 2019/2020 from Opto Engineering S.r.l., Italy, are from pages 78 to 79 [0007]

Claims (19)

A method for sorting foam particles and / or measuring the amount of foam particles comprising - optical scanning of foam particles by means of an optical sensor, - automatic evaluation of the quality of the individual foam particles according to a predetermined quality criterion and / or automatic counting of the foam particles, and - Removal of foam particles that do not meet the predetermined quality criterion, and / or portioning the amount of foam particles on the basis of the counted number of foam particles. Procedure according to Claim 1 , characterized in that the foam particles are separated before the optical scanning, so that essentially each foam particle is optically scanned separately. Procedure according to Claim 2 , characterized in that the separation is carried out with one or more of the following steps: - breaking lumps of foam particles by means of a rotary valve and / or screw conveyor, - shaking the foam particles with a vibrator, - moving the foam particles with an air flow, - stirring the Foam particles with a stirrer, and / or - feeding to a scanning area on an inclined chute. Method according to one of the Claims 1 to 3 , characterized in that the foam particles are transported through lines at least in some areas, the foam particles being added with liquid or vaporous water so that the foam particles are wetted on their surface in order to avoid clumping. Method according to one of the Claims 1 to 4th , characterized in that the foam particles are at least partially transported through lines, being blown with propellant air or sucked in by means of negative pressure. Method according to one of the Claims 1 to 5 , characterized in that the foam particles are scanned for brightness and / or color and / or shape. Method according to one of the Claims 1 to 6th , characterized in that the foam particles are irradiated with visible light and / or infrared light and / or luminescence generating light during the optical scanning. Method according to one of the Claims 1 to 7th , characterized in that the optically scanned foam particles are assessed according to one or more of the following quality criteria: optical scanning of the brightness and / or the color of the respective foam particles, wherein foam particles with a predetermined brightness and / or with a color which is within a predetermined Color range is assessed as sufficient for the quality criterion, with this being used to assess the smoothness and / or the surface quality and / or the moisture status of the foam particles and / or the type of foam particle in the case of a mixture of different foam particles, - determining the number of foam particles, where as Quality criterion a predetermined minimum number and / or a predetermined maximum number can be used. - Determination of the foam particles by means of object recognition, wherein the size and / or the shape of the foam particles can be assessed, and foam particles which have a predetermined minimum size and / or which have a predetermined maximum size are assessed as being sufficient for the quality criterion and / or foam particles, which deviate from a spherical shape by a certain amount as being judged to be sufficient or insufficient for the quality criterion, - scanning the foam particles by means of radiation which causes photoluminescence on the foam particles, and measuring the intensity of the light of the individual foam particles, the intensity of the light being approximately is proportional to the size of the individual foam particles and assessing the size of the foam particles based on the intensity to determine whether the foam particles have a predetermined minimum size and / or a predetermined maximum size in order to meet the quality criterion suffice, and / or - scanning the foam particles by means of infrared light and determining the brightness and / or color of the foam particles irradiated with infrared light, the moisture state of the foam particles being approximately inversely proportional to the brightness of the foam particles irradiated with infrared light or approximately proportional to a predetermined color scale. Method according to one of the Claims 1 to 8th , characterized in that the discharge takes place by means of a controlled air jet in that the movement path of individual foam particles is deflected in a controlled manner. Method according to one of the Claims 1 to 9 , characterized in that for portioning a quantity of foam particles these in a lock with at least one lock chamber can be introduced, the supply of the particles to the lock chamber being controlled as a function of the counted foam particles. Method according to one of the Claims 1 to 10 , characterized in that a measured amount of foam particles are fed to a mold which has two mold halves and the filling state on the mold is detected by means of a sensor, and if the sensor detects a filling level deviating from a target filling level, one or more the following steps are carried out: - In the event of overfilling, the mold halves of the tool are moved apart a little and / or a filling air pressure on a filling injector and / or a pressure in a supply line and / or a pressure in a material container is increased in order to accommodate all foam particles in the molding tool and / or a filling injector with a hold-down function is used, with which foam particles are pressed into the molding tool. - In the event of underfilling or overfilling, a correspondingly larger or smaller amount of foam particles is measured in the subsequent filling process. Apparatus for sorting foam particles and / or measuring the amount of foam particles comprising - an optical sensor for the optical scanning of foam particles, a control device for automatically evaluating the quality of the individual foam particles according to a predetermined quality criterion and / or for automatically counting the foam particles, and a device for discharging foam particles which do not meet the predetermined quality criterion and / or for portioning the amount of foam particles on the basis of the counted number of foam particles. Device according to Claim 12 , characterized in that a separating device is arranged upstream of the optical sensor in the direction of flow, which has an inclined chute on which the foam particles can slide down. Device according to Claim 13 , characterized in that a discharge device is arranged after the optical sensor in the flow direction, the discharge device preferably having a fall section and a nozzle for controlled generation of an air flow is arranged adjacent to the fall section, so that individual foam particles can be discharged. Foaming device for pre-foaming foam particles with a foaming container in which heat is supplied to pre-foaming foam particles, a device for sorting foam particles and / or measuring the amount of foam particles according to one of the Claims 12 to 14th is connected to an outlet of the foam container. Device for producing particle foam parts with a molding tool and a heating device for welding foam particles within a mold cavity of the molding tool to form a particle foam part, wherein a device for sorting foam particles and / or measuring the amount of foam particles according to one of the Claims 12 to 14th is arranged in the direction of flow in front of the molding tool. Device according to Claim 16 , characterized in that the molding tool is arranged horizontally. Device according to Claim 16 or 17th , characterized in that the device has several molding tools (4) and a counter (49) for counting foam particles is arranged upstream of each molding tool (4) in the direction of flow. Device according to Claim 18 , characterized in that each counter (49) is preceded by a switching valve (50) which can interrupt the supply of foam particles (2), whereby a carrier gas can flow unhindered through the switching valve (50).

Images