DE102020003391A1 - 3D printer for making and decorating bakery and confectionery products - Google Patents

Abstract

According to the invention, baked goods and / or confectionery goods are created by 3D printing, with melt being pressed through a print head by means of an extruder and the flow of melt being controlled by means of the print head.

Description

The bakery goods / baked goods include not only breads and rolls and the like, but also cakes and so-called particles (cakes or small baked goods) and cookies (fine baked goods / small baked goods). The term “particles” encompasses small baked goods, for example small yeast baked goods, snails (with dough wrapped in a snail shape) and many others. The term dough also includes the so-called masses used for bakery / confectionery products.

The particles are often covered with icing or pudding and topped with fruit.

In particular, cakes and particles and cookies can be produced in layers and / or provided with decorations. But bread and rolls can also appear with decorations.

The layers explained here can extend both in a plane and in space. The layers can also enclose other parts / layers.

Confectionery products include, in particular, cakes (especially tarts) and cookies.

The layer-by-layer structure is particularly common with cakes and biscuits.

In the case of a layered structure, the adjacent / superimposed layers can consist of the same material. This is useful if, for example, the layers are to have different shapes and production is facilitated by the layer-by-layer structure. The relief can be given, for example, by the fact that a lower or adjacent layer solidifies before an overlying or adjacent layer is applied.

• -Sa h neschichten
• -Cremeschichten wie Buttercreme. Buttercreme entsteht aus geschlagener Butter bzw. aus geschlagener Butter und geschlagenem Eiweiß oder Vollei
• -Marzipan. Marzipan kommt in diversen Formen vor und wird als Zutat in diversen Rezepten angeboten
• -Früchteschichten/Geleeschichten/Marmeladeschichten mit geeigneten Zusätzen wie Gelantine, Zucker usw.
• -Puddingschichten
• -Zuckerschichten. Üblicherweise findet die Zuckerschicht als Deckschicht Anwendung. Dabei wird von Zuckerguß gesprochen. Zuckerguß ist eine Zuckerglasur. Klassisch wird Zuckerguß aus Puderzucker und Wasser hergestellt. Der Zuckerguß härtet aus. Anschließend verhindert der Zuckerguß ein zu schnelles Austrocknen des Kuchens.

Often superimposed or adjacent layers in bakery and confectionery are made of different materials. This applies, for example, to the combination of (baked) layers of dough

• -Sa h neschicht
• -Cream layers like buttercream. Buttercream is made from whipped butter or from whipped butter and whipped egg white or whole egg
• -Marzipan. Marzipan comes in various forms and is offered as an ingredient in various recipes
• -Fruit layers / jelly layers / jam layers with suitable additives such as gelatine, sugar, etc.
• -Pudding layers
• -Sugar Layers. The sugar layer is usually used as a top layer. This is referred to as frosting. Frosting is a type of icing. Frosting is traditionally made from powdered sugar and water. The icing hardens. The icing then prevents the cake from drying out too quickly.

A spray glaze is a thick icing that is preferably used for decorating. Egg white icing consists of powdered sugar and egg white. Egg white icing becomes particularly firm and can be used as a glue between pieces of cake. The egg white glaze can also contain other ingredients, for example almonds.

• -Schokoladenschichten. Schokolade erweicht schon bei geringer Erwärmung
• -Farbschichten aus Lebensmittelfarben

The sugar layers can be produced at room temperature with different flow properties, both viscous / pasty and thin. For thick icing, less water is added, for thin icing, more water is added.

• -Chocolate Layers. Chocolate softens even when heated slightly
• -Color layers from food coloring

Confectionery is one of the confectionery products. Confectionery includes fine sugar and baked goods, also with candied fruit.

Confectionery also includes chocolates.

Chocolates can have different shapes, for example round, square, oval or mixed shapes.

Pralines usually have a chocolate outer layer and a filling. The filling can consist of nougat, nuts, liqueur, marzipan, fruits and others. The classic production of pralines uses a mold that is first lined with chocolate and then provided with the filling. Finally, the opening is closed with a chocolate chip. After the praline has solidified, it is shaped.

Chocolate bars can be structured like the pralines.

Chocolate bars can also consist of chocolate alone. The print heads can also be used for these chocolate bars bring great benefits. The present invention therefore includes not only chocolate bars with the same or similar structure as pralines, but also chocolate bars which consist only of chocolate.

This is taken into account by the fact that the term confectionery in the present case also includes chocolate bars, regardless of whether the manufacturers produce all types of pralines and chocolate bars at the same time, or whether they specialize in chocolate bars alone.

Marzipan is a confectionery made from ground almonds and sugar and possibly flavorings and water.

In the case of a layered structure of the baked goods or confectionery goods, at least one layer of dough is preferably provided. The layer of dough usually forms the bottom of the baked goods and confectionery products. Above the bottom are further layers, preferably made of cream and / or cream and / or cheese and / or yogurt and / or marzipan and / fruit and / or jelly and / or jam and / or pudding and / or sugar and / or chocolate and / or colors are provided, it being possible for further layers of dough to be provided between these layers. The layers of dough are usually used as prefabricated parts, the other layers are applied by hand.

• -Kakao/Schokolade. Zur Herstellung von Schokolade werden zunächst Kakaobohnen zu Kakao-Masse verarbeitet. Anschließend wird sie mit Zucker, Kakaobutter und Milchprodukten sowie mit Gewürzen vermischt. Diese Masse wird zwischen Walzen gebrochen und gerieben und Pflanzenfett hinzugegeben.
• -Vanillin
• -Nüsse
• -Mandeln
• -Datteln, Feigen
• -Zitronenpu Iver
• -Ei
• -Milch, Buttermilch
• -Gewürze wie Kümmel, Anis, Fenchel, Koriander

The dough used for bakery and confectionery products is regularly mixed. The mixture is preferably made from grain flour and water. In addition, baking powder / yeast and flavoring agents as well as salt are used as ingredients in the dough. In the dough or in connection with the dough, for example, can also occur

• -Coa / chocolate. To make chocolate, cocoa beans are first processed into cocoa mass. It is then mixed with sugar, cocoa butter and dairy products as well as with spices. This mass is broken between rollers and rubbed and vegetable fat is added.
• -Vanillin
• -Nuts
• - Almonds
• -Dates, figs
• - Lemon powder
• -Egg
• -Milk, buttermilk
• -Spices such as caraway, anise, fennel, coriander

The layers of dough are usually first baked and then coated.

For coating there is with the DE1577939 an automation proposal for a frosting. The baked goods are to be carried on a conveyor belt under various nozzles from which liquid sugar emerges. A variety of nozzles are provided. The nozzles can be opened and closed. The outlay on equipment is considerable.

The process is controlled by photocells, which give contact to open when the baked goods have reached the nozzles, and give another contact when the baked goods have left the area of the nozzles.

For several reasons, the well-known automation proposal had no chance of asserting itself in practice.

The device competes with manual coating with icing. When applying icing by hand, the outlay on equipment is comparatively almost negligible.

Added to this are the problems when starting up and shutting down the device. There are also other problems with complicated baking molds. The device does not appear to be very suitable for the production of different types of baked goods.

There will hardly be bakeries and confectioners who have enough baked goods of a type that approximately justifies the use of a known device.

Nevertheless, the invention has set itself the task of creating a device for the machine coating of baked goods and confectionery, which is suitable for a broader range of baked goods and confectionery and / or allows a more economical coating.

The invention uses a concept that was developed for 3D printing with plastics. The details are in the DE102019000712 described.

3D is short for three-dimensional. In the past, printers were only suitable for two-dimensional works. For some time now, 3D printers can also be used for three-dimensional works. The material is applied either point by point and / or as material threads / strips / bands. The material threads / strips / tapes can be short or long. In any case, the material points and / or material threads line up in such a way that a desired molded part is created. In the application of the According to the older proposal for 3D printing of bakery goods / baked goods and confectionery goods, these goods are the molded parts to be printed. It is advantageous if the molded parts to be produced are mapped as a file using software so that the printing process can be controlled with the stored data.

Optionally, several printing processes can also run side by side and / or be linked to one another. The same or different materials can be extruded. According to the invention, materials which are colored differently are already regarded as different materials

The older proposal for 3D printing of three-dimensional molded parts made of thermoplastic material is described below.

In 3D printing according to the older proposal, melt is pressed through a nozzle to the point of use. The nozzle forms the printhead. The point of use is a point at which the production of the molded part is to begin or to be continued. In the coordinate system with three axes (X-axis, Y-axis and Z-axis) the point is determined by values on all axes. When using 3D printing according to the older proposal, the following also refers to the processing of melt. Here, however, this term also includes plastic ingredients that are used for bakery products and / or confectionery products in the broadest sense. The ingredients can be plastic at room temperature, so they do not need to be melted. This is the case, for example, with dough, cream, cream and the other ingredients mentioned above. The room temperature is not always the optimal temperature. For cream, for example, it is better if the temperature is kept below room temperature. This is especially true on hot summer days. The extruder provided according to the invention can then advantageously be used at the same time for cooling the cream or another too temperature-sensitive feedstock. In addition, the cooling of the extruder provided can be used to divert the energy introduced into the melt by the extruder operation from the melt. The energy introduced leads to warming. The energy is dissipated by cooling the melt. Controlled cooling enables precise temperature control below room temperature. But maintaining a certain temperature can also be important above room temperature. This applies, for example, to the processing of chocolate. If the heat introduced into the extruded material by the extruder operation is not sufficient to achieve the desired temperature, additional heat can be introduced into the extruded material via the temperature control means. Like cooling, heating can also be controlled / regulated. The open-loop / closed-loop control is based on a target temperature value, which, if it falls below this, acts on heating until the target value is reached and, if it is exceeded, cools down until the target value is reached. Optionally, the control can be provided with damping. A reduction in the heating output during heating or a reduction in the cooling output during cooling as the temperature setpoint is approached is regarded as damping. The attenuation ensures that the temperature is easily applied to the setpoint or only slightly exceeds the setpoint. This leads to a very rapid leveling off at the setpoint when the setpoint is exceeded.

The temperature at which the work is carried out depends on the point at which the extruder is used in the production of the dough or other layer material / extrusion material. When making and working dough, the temperature is different than when baking. First, dough is created by mixing the ingredients, usually at room temperature. If this is done by hand, the mixture includes subsequent kneading, folding, kneading, beating, stirring and shaping (collectively referred to as kneading and shaping). With the extruder according to the invention, separate molding and shaping can be omitted because the extruder according to the invention kneads the ingredients at the same time. A low speed of rotation of the central spindle is preferably set during casting and molding. The speed can be below 60 rpm (revolutions per minute), based on the central spindle of a planetary roller extruder. Such low operating speeds only occur in extremely large extruders, not in small extruders. Large extruders, for example, have a size of 400 and more. In the case of planetary roller extruders, the size is derived from the pitch circle diameter of the internal gearing.
The throughput of such extruders is several tons per hour. Such a power requirement does not occur with baked goods and confectionery products, least of all with 3D printing of baked goods and confectionery products. A small extruder with a size of 30th or 50 (based on a planetary roller extruder design) is appropriate. Such extruders are usually operated at a much higher operating speed, based on the central spindle in the case of planetary roller extruder construction.

The low speed can also be advantageous for small extruders that have been selected to match the desired throughput with correspondingly low power.

The low speed gives the dough the opportunity to flow in the narrow spaces between the teeth of the planetary roller extruder. This leads to a result that is similar to kneading the dough.

The dough can be produced with interruptions in processing in the extruder or without interruption in the extruder. The interruption takes place preferably when yeast is used in order to give the dough or the yeast in the dough the opportunity to ferment. In some cases it is also sufficient if the dough is given the opportunity to ferment after sufficient mixing and kneading in the extruder according to the invention.

The dough can be processed in the extruder without interrupting the extrusion process if a leavening agent is added to the dough. As blowing agents, one or more suitable blowing agents can be selected from the series of blowing agents which are used for the production of polystyrene foam. This also includes alternative propellants such as water and carbon dioxide.

The propellants can be mixed in in gaseous or liquid form or in solid form. The liquid propellants should change into a gaseous form in the extruder. The solid propellants should split off gaseous components.

The amount of the respective leavening agent results from the fact that a similar increase in volume is aimed for as with conventionally produced and processed dough. This can be achieved with a few attempts by increasing the amount of propellant or reducing the amount of propellant compared to the amount of propellant in a first attempt.

It is important that the selected propellants do not pose a health risk.

It is favorable if the blowing agent can be mixed in the extruder and expands after exiting the extruder. The higher pressure in the extruder compared to the ambient pressure is preferably used. This means that if the leavening agent is mixed in in the extruder under a pressure which is significantly higher than the ambient pressure, the leavening agent expands immediately when the dough emerges from the extruder.

The blowing agent is preferably dimensioned in such a way that a foaming factor between 2 and 10, even more preferably between 2 and 7 and most preferably between 2 and 4 is given. This means that when the leavening agent expands, the dough volume is preferably doubled up to tenfold, even more preferably up to sevenfold and most preferably up to fourfold.

The dough exits the extruder through the nozzle.

• -die Düse wird in senkrechter/vertikaler Stellung über einer fest stehenden Unterlage in einer horizontalen Ebene (durch X-Achse und Y-Achse bestimmt) bewegt. Dabei kann der Extruder zusammen mit der Düse bewegt werden.

The options include:

• -the nozzle is moved in a vertical position over a fixed base in a horizontal plane (determined by the X-axis and Y-axis). The extruder can be moved together with the nozzle.

This solution has advantages for smaller extruders.

The extruder and the nozzle are then preferably held in a displaceable / displaceable housing part, which in turn is held in a displaceable / displaceable housing part, the directions of movement of both housing parts being transverse to one another so that every position in the plane can be reached. The setting of the device to a specific building product or the changeover to another building product can be effected with the control of the device.

Optionally, the extruder can also be moved during printing or the printing process can be displayed by moving the extruder alone.

• -die Unterlage wird unter einer fest stehenden, senkrechten/vertikalen Düse in eine horizontalen Ebene (durch X-Achse und Y-Achse bestimmt) bewegt
• -die Düse ist in senkrechter/vertikaler Stellung über einer Unterlage in einer horizontalen Ebene (durch X-Achse und Y-Achse bestimmt) bewegbar. Gleichzeitig ist die Unterlage unter der Düse in einer horizontalen Ebene (durch X-Achse und Y-Achse bestimmt) bewegbar.
• -die Düse wird in senkrechter/vertikaler Stellung zur Anpassung an die jeweilige Höhe des Punktes (auf der Z-Achse) senkrecht bewegt
• -die Unterlage wird in senkrechter/vertikaler Stellung der Düse zu Anpassung an die jeweilige Höhe des Punktes (auf der Z-Achse) senkrecht bewegt
• -sowohl die Düse, als auch die Unterlage sind zur Anpassung an die jeweilige Höhe des Punktes (auf der Z-Achse) senkrecht/vertikal bewegbar

A guide is then provided for moving the extruder. In addition, the extruder can also be arranged such that it can pivot in order to be able to lay melt strips next to one another. As an alternative to the swivel movement of the extruder, the nozzle can also be adjusted. Slides with which the melt emerging from the extruder can be deflected to the side are particularly suitable for this purpose.

• -The base is moved under a fixed, vertical / vertical nozzle in a horizontal plane (determined by the X-axis and Y-axis)
• -the nozzle can be moved in a vertical position over a base in a horizontal plane (determined by the X-axis and Y-axis). At the same time, the base under the nozzle can be moved in a horizontal plane (determined by the X-axis and Y-axis).
• -The nozzle is in a vertical / vertical position to adapt to the respective Height of the point (on the Z-axis) moved vertically
• -The base is moved vertically in the vertical / vertical position of the nozzle to adapt to the respective height of the point (on the Z-axis)
• - Both the nozzle and the base can be moved vertically / vertically to adapt to the respective height of the point (on the Z-axis)

The movements are preferably carried out with a computer.

It is advantageous to use the data from a computer-aided drawing program with which the molded part is designed / mapped at the same time for moving the nozzle and / or the base. The best-known drawing / construction program is the CAD program. This program as well as other drawing programs can serve as the basis for software development.

Regardless of this, there are control programs that can be used directly or with minor changes to control the 3D printing according to the invention. Such control programs for the movement of the print head / nozzle can also be control programs from other machines, for example from automatic milling machines.

There are also commercially available robots that can carry the print head and can be swiveled in all directions. The associated controls are able to carry out the finest steps in all directions with one tool, both on a straight line and on a curved path. You only have to enter the data with which the position of the melting points / threads / bands / strips is described.

Such controls can also work within wide limits at different speeds. Such controls are also able to bridge a movement to another location in overdrive at a speed many times higher than the working speed.

According to the invention, the print head from the older proposal is used for the production of baked goods and confectionery.

If the goods are uniform, the melt can be evenly discharged from the nozzle. Such uniform shaped parts are, for example, cylindrical cakes. To produce cylindrical cakes, the print head and / or the resulting cake can always be moved in a circle until a desired layer is completed. On the other hand, small cakes and chocolates can minimize the time the print head is used, so that printing stops as soon as it has started. But even then, the printhead provided according to the older proposal is of great help because it works much more precisely and much more evenly than a baker or confectioner.

The superiority of the printhead according to the older proposal is particularly evident in the case of uneven molded parts.

This means that the more uneven a product is, the more economical it can be to manufacture using a 3D printer.

For the purposes of the invention, any baked good or confectionery product that requires a different melt outlet is uneven. This is the case with changes in thickness as well as breakouts / breakthroughs in walls, but also at corners. While changes in thickness can be taken into account with a change in the nozzle movement / substrate movement and / or with a change in the amount discharged from the nozzle per unit of time, an interruption / change in the melt flow may be necessary in the case of breakouts / breakthroughs. Even the production of goods with different dimensions can make 3D printing according to the invention economical.

Regardless of this, it can already be advantageous to only print out the goods on request with the aid of the 3D printer according to the invention in order to avoid stockpiling.

In the application of the older proposal to baked goods and confectionery, plasticized foods are applied with the printer instead of plastics. Some of the food is plastic by default.

If this is missing, the plasticization can be brought about by heating and / or deformation work. This has the advantage that after the printing and cooling of the food and / or the end of the deformation work, the food solidifies.

This is easy to understand with chocolate.

Chocolate liquefies when heated and deformed, so that it can be printed with the printer according to the older proposal and solidifies in the printed form after cooling. In the case of sugar, plasticization can be brought about by heating and deformation work. But sugar can also be liquefied with water.

Other foods or food mixes are plastic even at room temperature and solidify after printing because the food mix contains a setting agent. A such setting agent is, for example, egg, especially egg white in beaten form.

Marzipan is inherently plastic, so that marzipan is permeable to the print head, but keeps the shape it has acquired after printing, even under the load of further layers of food.

The printing according to the invention is achieved with the features of the main claim. The subclaims describe preferred exemplary embodiments of the invention.

• -Verschluß, mit dem sich eine sichere und vorteilhafte Anpassung der Schmelzemenge an den jeweiligen Bedarf erreichen lässt
• -ein Extruder mit einem Schmelzevolumen, das für den jeweiligen Bedarf ausreicht

Are important

• -Closure with which a safe and advantageous adjustment of the amount of melt to the respective need can be achieved
• -an extruder with a melt volume that is sufficient for the respective requirement

According to the invention, a displaceable nozzle and / or an extruder is optionally provided, the screw / spindle of which is adjustable in the axial direction and forms the adjusting element for a closure / stopper of the nozzle from which the melt is discharged during printing. By moving the screw / plug, the nozzle can be opened completely or partially or closed completely or partially.

The screw / spindle optionally forms a tip that protrudes into the nozzle opening at least in the closed position. This can prove to be advantageous if the baked goods or confectionery goods have small dimensions and a low weight. Then the restriction of the horizontal freedom of movement associated with the vertical / vertical position of the screw / spindle with horizontal freedom of movement of the base is of no consequence.

However, larger baked goods and confectionery products are also conceivable, the dimensions and weight of which cause some difficulties in moving the baked goods or the confectionery goods and a base / work table carrying these goods.

In the case of a screw / spindle protruding into the nozzle, the nozzle opening or the tip of the screw / spindle has a shape that tapers in the flow direction of the melt.

The screw tip / spindle tip can have a wedge shape. Then the nozzle / nozzle opening is adapted to this.

Preferably the nozzle opening and the screw tip / spindle tip have a conical shape.

The screw tip / spindle tip can also have a spherical shape or another, in particular spherical, round shape. A tapered nozzle as well as a nozzle with a cylindrical opening can be combined with such a tip.

• -eine Schneckenspitze/Spindelspitze, die sich in gleicher Weise verjüngt wie die Düsenöffnung, und sich mit einer axialen Bewegung der Schnecke/Spindel in die Düse hineinbewegt und die Düse teilweise oder ganz verschließt bzw. sich mit einer axialen Bewegung der Schnecke/Spindel aus der Düse herausbewegt und die Düse ganz oder teilweise öffnet.

The opening of the nozzle, which tapers in the melt flow direction, can correspond

• -a screw tip / spindle tip that tapers in the same way as the nozzle opening and moves into the nozzle with an axial movement of the screw / spindle and partially or completely closes the nozzle or moves out of the nozzle with an axial movement of the screw / spindle The nozzle is moved out and the nozzle opens completely or partially.

• --bis über die Düsenspitze hinausragen. Dann ist die Schneckenspitze/Spindelspitze im Durchmesser kleiner als die Düsenöffnung an dem Ende, welches in Strömungsrichtung der Schmelze weist.
• -- oder mit der Düsenspitze abschließen. Dann ist die Schneckenspitze/Spindelspitze im Durchmesser gleich dem Durchmesser der Düsenöffnung an dem Ende, welches in Strömungsrichtung der Schmelze weist.
• --vor der Düsenspitze enden. Dann ist die Schneckenspitze/Spindelspitze im Durchmesser größer als die Düsenöffnung an dem Ende, welches in Strömungsrichtung der Schmelze weist.

Depending on the diameter of the screw tip / spindle tip, the screw tip / spindle tip can be in the closed position

• - protrude beyond the nozzle tip. Then the screw tip / spindle tip is smaller in diameter than the nozzle opening at the end which points in the flow direction of the melt.
• - or finish with the nozzle tip. The diameter of the screw tip / spindle tip is then the same as the diameter of the nozzle opening at the end which points in the direction of flow of the melt.
• - end in front of the nozzle tip. Then the screw tip / spindle tip is larger in diameter than the nozzle opening at the end which points in the flow direction of the melt.

• -eine Schneckenspitze/Spindelspitze, die sich anders verjüngt als die Düsenöffnung. Dabei kann die Schneckenspitze/Spindelspitze bei Keilform oder konischer Form zur Schneckenachse/Spindelachse eine geringere Neigung oder eine größere Neigung als die Düsenöffnung aufweisen. Bei geringerer Neigung der Schneckenspitze/Spindelspitze kommt es in Abhängigkeit von dem Durchmesser der Schneckenspitze/Spindelspitze zur Berührung einer Kante des Schneckenspitze/Spindelspitze mit der Mantelfläche der Düsenöffnung oder zur Berührung einer Kante der Düsenöffnung mit der Mantelfläche der Schneckenspitze/Spindelspitze.

In each closed position, the outer surfaces of the screw tip / spindle tip run parallel to the outer surface of the nozzle opening.

• -a screw tip / spindle tip that tapers differently than the nozzle opening. In this case, the screw tip / spindle tip in the case of a wedge shape or a conical shape to the screw axis / spindle axis can have a lesser inclination or a greater inclination than the nozzle opening. If the inclination of the screw tip / spindle tip is less, it depends on the diameter of the screw tip / spindle tip for contacting an edge of the screw tip / spindle tip with the outer surface of the nozzle opening or for contacting an edge of the nozzle opening with the outer surface of the worm tip / spindle tip.

• --zu einer Berührung der Schneckenspitze/Spindelspitze mit der Mantelfläche der Düsenöffnung oder
• --zu einer Berührung der Kante der Düsenöffnung mit der Mantelfläche der Schneckenspitze/Spindelspitze.

-With the spherical shape or other round shape of the screw tip / spindle tip, the conical shape of the nozzle opening depends on the diameter of the screw tip / spindle tip

• - to a contact of the screw tip / spindle tip with the outer surface of the nozzle opening or
• - to a contact of the edge of the nozzle opening with the lateral surface of the screw tip / spindle tip.

The movement of the screw / spindle according to the invention is optionally achieved in that the screw / spindle is arranged in the associated extruder housing such that it can be displaced in the axial direction. Various drives are possible for the axial displacement, both hydraulic and mechanical. The hydraulic drives have a hydraulic cylinder / power piston acting in the axial direction on the worm / spindle with a position control / step control. With an electronic distance measurement, even small distances / adjustments can be measured and controlled.
Electric lifting devices can also be used as a drive for the axial movement of the screw / spindle. Electric lifting devices / power pistons are particularly suitable for fast and frequent closing and opening movements. This means that electrical lifting devices / power pistons are particularly suitable for short threads / ribbons / strips and correspondingly short melt flow intervals. This is even more true when small temperature ranges have to be adhered to.

Even with the axially displaceable arrangement, the screw / spindle can be set in rotary motion at the end facing away from the nozzle by means of a motor and a gear unit. For this purpose, for example, a drive wheel with a spline connection can sit on the worm / spindle. The multi-spline connection allows the worm / spindle to be displaced when the drive wheel is held in the axial direction with the necessary play for a rotary movement.

An inexpensive drive connection between the worm / spindle and the drive provides a belt drive with one or more V-belts. The V-belt allows a fixed arrangement of the drive wheel on the worm / spindle with simultaneous displacement according to the invention. This is especially true for small shifts. The displacements can be kept small even with a considerable height of the molded parts to be produced by adjusting the base.

Optionally, instead of or in addition to the axial adjustability of the screw / spindle, an axial adjustability of the nozzle is provided in order to partially or completely open or close the nozzle. The nozzle is either moved against the screw tip / spindle tip or moved away from the screw tip / spindle tip. The same drives and controls as for the axial movement of the screw / spindle are suitable as a motion drive for the axial movement of the nozzle.

Optionally, a slide can also be used as a closure.

The nozzles described above are particularly advantageous for a system with vertically / vertically moved nozzle or vertically / vertically moved screw / spindle and both vertically moved and horizontally moved base / workbench. The vertical / vertical arrangement allows the melt to be deposited downwards. That works particularly well. In addition, the melt has no appreciable tendency to flow away from the deposit position.

In addition, the nozzles described above can also be used if the nozzles, together with the extruder feeding the nozzles with melt, can be moved horizontally. The nozzles and the associated extruder are referred to below as the system.

Alternatively and / or in addition to moving the nozzles, the baked goods / confectionery goods can also be moved.

When the system is moving, it is helpful if the nozzle not only has an open / closed function and can not only deposit the melt on a line, but can also distribute the melt at the same time on an area that is wider than, for example, one Melt thread / strip / ribbon or a melting point. This is the case, for example, if a 3D printer is to produce a larger part / layer of the baked goods / confectionery in one operation. Then the 3D printer should deposit the melt over the entire width of the baked goods / confectionery goods. This can be done in dots or with threads or ribbons / threads / strips.

The production of parts of a bakery product / confectionery product can also take place with the formation of closed layers or with the formation of cavities. Particular advantages in the formation of cavities result if the closed outer layers of the walls are connected to one another by webs and if the webs run at different angles between the layers. For example, one webs can run at a 45 degree incline in one longitudinal direction of the walls and the other webs at 45 degrees incline in the opposite longitudinal direction of the walls. Optionally, the webs can cross each other. This creates cavities and a stiff connection and allows ventilation if necessary; possibly can the cavities can also be used to route individual or all media occurring during production.

Optionally, the cavity formation takes place with the formation of uniformly thick layers. The cavities can each be closed. This is also possible with the formation of watertight cavities. The cavities can be designed as desired. Cavities with particular static strength and particularly advantageous deformation behavior under load are advantageous. Suitable cavities are, for example, modeled on closed honeycombs.
The closed cavities also offer advantageous thermal insulation.

Optionally, the cavities are also at least partially connected to one another. This can advantageously be used to create a connection between the cavities in the perpendicular / vertical so that moisture that penetrates by diffusion can evaporate upwards.

The above constructions can be realized with the laying of melt bands and / or melt threads and / or melt strands and / or melt points. Melt ribbons / threads / strands make printing easier by allowing a longer flow of melt in the form of melt threads / strands / ribbons. Melt threads contain a thin layer of melt. Melting ribbons / strands are many times the width of melt threads. They can have the same thickness as melt threads, but also a multiple of the thickness of melt threads. The greater thickness is an advantage where work is carried out with a larger application rate. Even with melt ribbons / threads / strands, an interruption in the ribbons / threads / threads must be taken into account. In contrast, the melt flow is extremely often interrupted in the case of pointwise melt transfer. Electrically operated lifting devices are particularly suitable for the point-wise laying of melt.

While only a single layer / layer is created with the printing material in two-dimensional printing units, several layers / layers are laid on top of one another in three-dimensional printing units.
Usually a line-by-line approach is used in each layer / layer. The line-by-line mode of operation has the disadvantage of considerable idle movements of the printer and / or considerable idle movements of the molded part. According to the invention, there is a significant increase in the printing performance when the line-by-line printing is limited to the bottom surfaces of the baked goods or confectionery goods, ie is reversed when an edge of the bottom surface is reached.

Advantageously, the laying does not have to be interrupted if a change is made to the adjacent row when changing direction. The pressure then takes a meandering course.

If, after completion of a floor area, webs with a correspondingly small contact area are to be produced and the contact areas are treated like a floor area, the reversal processes increase. In the case of contact areas of webs, a transition is preferably made to a direction of movement along the webs. The new direction of movement can be programmed in this way. Alternatively, in the case of baked goods or confectionery goods, the workbench on which the baked goods or confectionery goods are set up can be rotated until the direction of movement of the printer runs in the direction of a web. Instead of rotating the workbench or in addition, rotating the extruder with the nozzle and other accessories can facilitate the alignment of the printer movement with the course of the wall to be printed. Even the rotational mobility of individual parts such as the nozzle can be helpful for aligning the direction of movement of the nozzle on a web.

In the production of baked goods and confectionery goods, it can be advantageous if the extruder together with the nozzle and other accessories for printing over the baked goods or confectionery goods can be moved / moved in any direction. Alternatively or additionally, the work table on which the melt strips / threads / strands are placed can be moved in individual directions or in any direction.

For the desired movement of the nozzle / print head and possibly the extruder, the nozzle / print head can optionally be held with a robot. The nozzle / print head and the extruder can be designed with a small volume. The dimensions of the nozzle / print head usually follow the overall volume of the extruder. This means that small nozzles / print heads are also regularly used for small extruders. In the application according to the invention, the extruders preferably have a maximum screw length of 500 mm, even more preferably a maximum screw length of 400 mm and most preferably a maximum screw length of 300 mm. In single-screw extruders, the screw length is the length of the teeth on one screw. The same applies to twin screw extruders. In the twin screw extruder, the two screws that occur mesh. This means that the two worms that occur interlock with their teeth.

In the case of planetary roller extruders, the screw length is the length of the planetary spindles. The planetary roller extruders meant here have a Fixed housing, a central spindle rotating in the housing and various planetary spindles which rotate between the central spindle and the surrounding housing. The central spindle and the planetary spindles have external teeth and the housing has internal teeth. The planetary spindles mesh (with their teeth) with the central spindle (with their teeth) and at the same time with the housing (with their teeth).

The toothing of all toothed parts is preferably an involute helical toothing. This means that the teeth form an involute toothing and run on the outer surface of the central spindle and planetary spindles with a gradient in relation to the central axis. At the same time, all toothed parts have the same tooth module. The tooth module defines important details of the toothing.

The planetary spindles rotate around the central spindle during operation. The planetary spindles are under pressure in the longitudinal direction due to the helical gearing. The pressure is directed towards the discharge end of the extruder. This pressure is absorbed by thrust rings at the end of the extruder. The planetary spindles slide on the thrust ring as they revolve around the central spindle.

Commercially available robots can be used for the production of baked goods and confectionery products. Such robots have a control that is able to deposit all melt bands / threads / strands in the desired length at the desired location when entering the dimensions of the paths and their position relative to one another and their height. These robots can contain a step-by-step control.

Laser control for the robots can also be considered. Several lasers are preferably used, which direct the extruder with the nozzle to any desired point.

• -der Drucker kann in Längsrichtung eines Steges ein langes Schmelzeband/Faden/Strang legen. Das nächste lange Schmelzeband/Faden/Strang wird auch in Längsrichtung des Steges, aber zugleich um Einiges versetzt, neben das vorher gelegte Schmelzeband/Faden/Strang gelegt
  • -- die längeren Schmelzebänder/Faden/Stränge können dabei schließend nebeneinander liegen
  • --die längeren Schmelzebänder/Faden/Stränge können dabei einander seitlich überlappend verlegt werden
  • --die längeren Schmelzebänder/Faden/Stränge können unter Bildung eines horizontalen Abstandes voneinander verlegt werden
    • ---in Abständen erfolgt eine Verbindung beider beabstandeter längerer Schmelzebänder/Faden/Stränge durch kurze Schmelzebänder/Faden/Stränge

Below are some of the different possible procedures with short and longer melt ribbons / threads / strands:

• -The printer can lay a long melt ribbon / thread / strand in the longitudinal direction of a web. The next long melt band / thread / strand is also placed in the longitudinal direction of the web, but at the same time offset by some, next to the previously laid melt band / thread / strand
  • - The longer melt ribbons / thread / strands can close next to each other
  • - the longer melt bands / threads / strands can be laid laterally overlapping each other
  • - the longer melt bands / threads / strands can be laid with a horizontal distance from each other
    • --- At intervals there is a connection between the two spaced longer melt bands / threads / strands by short melt bands / threads / strands

By changing the arrangement of long and short melt strands / threads / bands and / or offsetting the melt strands / threads / bands, a bond / bond is created in every layer / layer of melt strands / threads / bands. The fact that the melt strands / threads / ribbons are offset in relation to the melt strands / threads / ribbons in the previously laid layer / layer also results in an offset of the melt strands / threads / ribbons in each new layer / layer, the bond / bond of the melt strands / threads / ribbons is further improved.

• -an Kreuzungsstellen/Stoßstellen von Schmelzebändern/Faden/Strängen wird vorzugsweise vermieden, dass Schmelzebänder/Faden/Stränge in derselben Schicht/Lage übereinander gelegt werden.

In a variant, entirely or partially narrower or wider melt bands / threads / strands can be laid alternately (from layer / layer to layer / layer). The wider melt bands / thread / strands can be, for example, twice as wide as the narrower melt bands / thread / strands. Alternatively, the ratio of the narrower widths to the larger widths is between 1: 1.1 and 1: 4.

• -at intersections / joints of melt bands / threads / strands is preferably avoided that melt bands / threads / strands are placed on top of one another in the same layer / position.

In the case of two superimposed layers / plies, it goes without saying that the associated melt bands / threads / strands are superimposed on one another. A constant thickness is preferably maintained in each layer / layer. According to the invention, this is achieved by using longer melt bands / threads / strands (for example melt band 1 called) in front of another melt band / thread / strands (for example melt band 2 called) and after the other melt band 2 start all over again. The melt band 1 is thereby removed from the melt band 2 interrupted.

Proceeding exactly the same at every intersection / joint includes a procedure.

• -vorzugsweise werden Kreuzungsstellen/Stoßstellen entsprechend ausgelegt. Mit Kreuzungsstellen/Stoßstellen sind dabei die Stellen gemeint,
  • --an denen zwei Schmelzestränge/Fäden/Stränge fluchtend aneinander stoßen
  • --an denen zwei Schmelzestränge/Fäden/Stränge T-förmig oder L-förmig aneinander stoßen oder
  • --an denen Schmelzebänder/Fäden/Stränge
    • ---an eine Bodenfläche des Formteiles
    • ---an einen Zwischenboden
    • ---an einen Deckel
    • ---an einen Vorsprung des Teiles
    • ---oder dergleichen stößt.

There are other approaches as well
A strength advantage arises if a bond is made at all intersections / joints. Association means that the components abutting one another are connected to one another by integrating melt bands / threads / strands of one part of a product between melt bands / threads / strands of the other component. A The bandage according to the invention arises when the melt bands / thread / strands cross one another when the melt band is in the next melt layer / layer 2 in front of the melt band 1 ends and after the melt band 1 is rescheduled. This causes the melt band to run 1 at this crossing point while the melt band 2 is interrupted.

• -Preferably, intersections / joints are designed accordingly. With intersections / joints are meant the points
  • - at which two melt strands / threads / strands are flush with one another
  • - at which two melt strands / threads / strands meet in a T-shape or L-shape, or
  • - on which melt bands / threads / strands
    • --- to a bottom surface of the molded part
    • --- to an intermediate floor
    • --- on a lid
    • --- to a ledge of the part
    • --- or the like comes across.

A bond / bond is advantageous at all joints / intersections.

The T-shaped abutment differs from the crossing points in that the melt strands / threads / strands adjoining continuous melt strands / threads / strands do not continue on the opposite side of the continuous melt strands / threads / strands. This preferably stays at the top of the melt belt 1 and melt band 2 The explained principle is obtained, in one layer / layer is the melt band 1 continuously laid and abuts the melt band 2 to the continuously laid melt band 1 . The melt band is in an overlying layer / layer 1 in the width of the melt band 2 interrupted and extends the melt band 2 in this gap.

Joints / crossing points can also result according to the invention when the melt strands / threads / strands form a corner. Then the melt strands / threads / strands meet in an L-shape. This joint differs from the T-shaped joint in that no melt strands / threads / strands go through (go beyond the corner). Then the melt band ends 1 in a layer in front of the corner at a distance equal to the width of the melt band 2 is so that the melt band 2 can be led / placed in the gap. The melt band ends in the layer / layer above 2 at a distance from the corner equal to the width of the melt band 1 is so that the melt band 1 can be led / placed in the gap.

As an alternative to the above corner formation, the melt band / thread / strand can also be angled at the corner. The melt band / thread / strand is angled at the corner and continued without interruption. In principle, this can be done with any melt band / strand / thread. The best results are seen with thread / strands from a nozzle with a circular cross-section.

The connection of melt strands / threads / strands to a bottom surface or the like is preferably solved in the same way as the T-shaped joint, because the bottom surface is also composed of different melt bands / threads / strands.

If a product is built up in layers / layers, several melt strips / threads / strands can lie next to one another and / or one behind the other on one level. An offset is then preferably provided between the melt bands / thread / strands of a layer / plane and the melt bands / thread / strands of an overlying layer / plane or an underlying layer / plane. The offset is at least 1mm, preferably at least 2mm, even more preferably at least 3mm and most preferably at least 4mm. This advantageously leads to interlocking of the various layers.

Usually threads have a much smaller cross-section than ribbons. If the melt belts are replaced by melt threads during a production process, much more melt threads have to be laid than melt belts in order to produce the same baked goods or confectionery.

For printing, the melt must be introduced into the print head with sufficient pressure that is as uniform as possible. A twin screw extruder connected upstream of the print head in the melt flow direction is suitable for this purpose. A single-screw extruder, even more preferably a planetary roller extruder, is preferably used as the extruder. All of the named types of extruder have a filling part into which the food intended for printing is filled. The filling part is followed by an extruder part, in which the food is brought to the temperature and pressure required for printing. If necessary, degassing can also take place, as can a mixture with additives, aggregates and fillers.

Advantageously, the planetary roller extruder can also be used to optimally control the temperature of the food prior to printing. For this purpose, a temperature control medium, preferably water, flows through the planetary roller extruders. To heat the food, heat is introduced into the extruder with the temperature control medium. For cooling, heat is removed from the extruder with the temperature control medium.

Earlier extruders performed all tasks in one housing, from drawing in to discharging the extrusion material. Modern extruders are built up in modules.

If the extruders are composed in sections, the sections can all have different lengths. This can be advantageous in order to adapt the length of the individual sections to the respective processing zone / treatment zone for the feedstock in the extruder. Most of the sections of the extruder are all of the same length. This is known as the modular structure of the extruder. The terms “section by section” and “by module” or “section” and “module” are often used synonymously.

The sections / modules of the single-screw extruders usually have common screws. That is, the screws extend through all sections / modules.

The same applies to the sections / modules of the twin screw extruders. In the case of planetary roller extruders, a common central spindle is provided for planetary roller extruders constructed in modules or sections.

• -Gehäuse
• -Gehäusebuchse
• -Planetspindeln
• -Anlaufringe

In the case of single-screw extruders and twin-screw extruders, the modular or sectional structure is limited to the housing. In the case of planetary roller extruders constructed in modules and sections, the following parts are made up of modules / sections:

• -Casing
• -Housing socket
• Planetary spindles
• -Stop rings

The housing sleeve is usually held in the housing by shrinking the housing. The thrust rings are mounted in bores / openings in the relevant housing ends. Either the thrust rings simultaneously engage in a bore / opening in the adjacent extruder module / extruder section. Or the thrust rings are part of a ring construction which is inserted into a bore / opening of the adjacent extruder module / extruder section.

In the case of modular extruders (the screw / spindle extends from the drive through all modules to the nozzle), each module can take on one or more partial tasks. For example, a separate extruder module can be used for heating / cooling. Optionally, a separate extruder module can also be used for a desired degassing. This module is referred to below as the degassing module. The degassing module has a jacket opening through which gas can escape. An idle side arm extruder is preferably provided at this jacket opening. Even more preferably, the side-arm extruder is a twin-screw extruder which rotates without feed material as if it were conveying feed material into the degassing module. As a result, the side arm extruder keeps the melt in the degassing module from exiting through the jacket opening. A particularly short side-arm extruder is preferably used. A simultaneous induced draft on the side arm extruder draws off gas as a result of a deliberate leak in the side arm extruder. The necessary clearance between the screws of the side arm extruder and the surrounding housing can be sufficient as a leak. If necessary, additional play is created between the screws of the side arm extruder and the surrounding housing. This can be done by machining the screws on the outer circumference.

The side arm extruder can be arranged to the side or above the degassing module or below the degassing module.

The inventive use of the print head according to the older proposal for the production of baked goods and confectionery also includes a corresponding control of the print head when the printing speed is changed and even when printing is interrupted. The change in the printing speed leads to a change in the melt flow, that is to say to an increased melt flow or to a reduced melt flow. If printing is interrupted, the flow of melt from the print head must also be interrupted. In particular, the interruption leads to serious problems, because the system normally has to be shut down and started up again. The use of printing according to the older proposal also means that the melt properties are largely retained despite the change in the melt exit from the print head. For this purpose, the melt is at least partially circulated. For this purpose, a leakage flow is generated according to the older proposal.

In the case of a single screw extruder and a twin screw extruder, this is achieved with one or two screws with a reduced conveying effect. A single-screw extruder and a twin-screw extruder normally have such a high conveying force that considerable pressures arise during operation, which make it difficult to adapt to a reduced demand for melt.
The high pressure is avoided with a reduced pumping effect or a leakage flow.

The conveying effect of all screws can also be reduced in that at least one screw has one or more counter-rotating screw flights.
Each screw thread of a screw has a certain pitch. The counter-rotating worm threads have a different pitch, in fact in such a way that the counter-rotating worm threads increase in relation to the longitudinal screw axis when the original screw thread decreases in relation to the longitudinal screw axis. Conversely, a falling course of the counter-rotating worm threads is provided if the original worm thread is rising. As a result, screw flights running in opposite directions have an opposing conveying effect. In order to still achieve a conveying effect in the original conveying effect, the counter-rotating worm flights are provided with an overall lower conveying effect. This is achieved by the fact that the number of counter-rotating screw flights is smaller and / or the cross-section of the counter-rotating screw flights is smaller. All worm flights are preferably produced with the same milling tool. Nonetheless, different cross-sections are created in that the milling tools for the counter-rotating worm threads are worked less deeply into the worm material.

Additionally or alternatively, the screws of all extruders can be provided with a reduced diameter so that a larger gap is created between the screws and the surrounding housing. The cylindrical screws can also be provided with flats or recesses on the circumference.
There are gaps through which the material can evade and even flow back. A deliberate leakage flow arises. The larger the gaps, the better the plastic food can flow back into the extruder. This continues until the melt is caught again by the screw and pressed in the direction of the extruder outlet. If no melt is picked up at the nozzle, the melt can again evade by way of the leakage flow.
In the single-screw extruder and the twin-screw extruder, setting the correct leakage flow is incomparably complicated compared to the situation with a planetary roller extruder.
In the case of a planetary roller extruder, a change in the leakage flow can not only be brought about by changing the various extruder parts. The change in the number of planetary spindles includes a particularly advantageous procedure for changing the leakage flow. The leakage flow is increased when the number of planetary spindles is reduced. The leakage flow is reduced when the number of planetary spindles is increased.

The leakage flow can be viewed as “going in circles” of the melt. In combination with a regulation of the melt outlet at the nozzle, an extremely advantageous procedure results, because the melt is kept liquid in the extruder and circulated until there is a need for a melt outlet. If necessary, the nozzle opens and a desired melt outlet is created. According to the invention, the melt outlet at the nozzle is regulated. At the same time, the amount of melt emerging from the extruder is replaced by feeding further feedstock to the extruder. A level control can be used here, in particular when the extruder is arranged upright instead of lying down.

The greater the amount of melt moved in this way, the easier it is to keep a melt requirement for 3D printing and regulate the supply.
The leakage flow and the cavity volume of the extruder are decisive for the amount of melt.
After opening the nozzle, melt flows off for 3D printing.
The cavity volume of the extruder is the interior space of the extruder minus the volume of the screw and other internals that protrude into the extruder.

The degree of filling of the extruder can be measured in various ways. Optionally, the measurement can be carried out by positioning a measuring sensor in the jacket of the filling part. The probe can include any form of measurement that is melt responsive. These include, for example, pressure, temperature, ultrasound and other sounds. The degree of filling is preferably determined by weight measurement or by optical volume determination. If the filling level falls below a predetermined level, feedstock for the melt production is added.

When determining the weight, favorable ratios result if the weight of the molded part on the base / workbench is measured. The melt consumption can be calculated from the weight. the Weight measurement is preferably carried out electronically by means of a microchip.
The electronic measurement can advantageously be carried out at the same time when the base / work table is in a rest position so that the measurement results are not falsified by acceleration forces and braking forces. In addition, the effects of the acceleration forces and braking forces can also be calculated or added to the results of the weight measurement.

With the optical volume determination, the molding in progress is measured on the base. There are various ways of doing this. It is advantageous to measure the smallest distance between the nozzle and the molded part. A laser measuring device is suitable for this.

The distance measurement is advantageous anyway to ensure constant conditions for the melt application. With the values of the distance measurement, not only the necessary feeding of melt into the extruder, but also the movement of the base / workbench in the axial direction of the nozzle and / or the arrangement of the nozzle can be controlled.

A reduced conveying effect according to the invention can also be brought about with a bypass which begins in the conveying direction of the extruder in front of the nozzle and returns all or part of the melt to a suitable section of the extruder. Only part of the melt is returned when the nozzle is partially closed or only partially open. Overall, the melt is returned when the nozzle is completely closed. A suitable section for the return of the melt evacuated into the bypass can be the area of the melt generation or a point spaced apart therefrom in the conveying direction of the extruder.

The bypass is a preferably thermally insulated (possibly also heated) pipeline. One end of this pipeline is flanged to an opening in the jacket of the extruder in front of the nozzle in the conveying direction of the extruder. The other end of this pipeline is flanged in the conveying direction of the extruder to a further opening in the jacket of the extruder, which is located in the area of the melt generation or behind it in the conveying direction.

• -eine vielfach bessere Mischwirkung
• -eine vielfach bessere Temperierung

Planetary roller extruders are better suited for 3D printing than single-screw extruders and twin-screw extruders. The leakage flow according to the invention can be generated much more easily with a planetary roller extruder than with a single-screw extruder.
In addition, the planetary roller extruder has other extremely important advantages over the single screw extruder. This includes in particular

• - a much better mixing effect
• - a much better temperature control

The planetary roller extruder has a rotating central spindle arranged in the center of a housing. The central spindle is toothed on the outside. Planetary spindles run around the outside of the central spindle, which are also externally toothed and mesh with the central spindle as it rotates. The planetary spindles also rotate in the extruder housing. For this purpose, the extruder housing or the bushing, in the case of a bushing provided inside the extruder, is provided with internal teeth with which the planetary spindles mesh at the same time.

The planetary spindles slide with the rear end in the conveying direction of the extruder on a sliding ring which is held in the extruder housing. In addition, the planetary spindles are held solely in the toothing of the central spindle and the internal toothing of the housing.

The planetary roller extruder also begins with a drive and ends with the nozzle. In between, the planetary roller extruder can be provided with a one-piece housing extending over the entire length. The planetary roller extruder can also be composed of several modules / sections between the drive and the nozzle. A common central spindle extending through all modules is then provided between the drive and the nozzle.

The individual modules / sections can take on one or more different tasks. All modules / sections of the planetary roller extruder are preferably designed in planetary roller extruder construction. Modules / sections in a planetary roller extruder design can also be combined with modules / sections in a different design. This is especially true for the filler part. The modules / sections for the filler parts used to be mostly single-screw extruder designs. In this case, the central spindle continued in the module / section for the filling part as a single screw.

The planetary roller extruders for use in printing 3D molded parts can also have a reduced conveying effect.

• -die Planetspindelzahl(Zahl der umlaufenden Planetspindeln) kann reduziert/verändert werden. Je nach Baugröße des Planetwalzenextruders/Planetwalzenextrudermoduls/Abschnitts kann die Planetspindelzahl bis zu 24 und mehr betragen. Bei kleineren Baugrößen kann die Planetspindelzahl auch 5 oder 6 betragen. Die Reduzierung der Planetspindelzahl um 1 beinhaltet bei kleineren Baugrößen schon eine wesentliche Reduzierung. Bei größeren Baugrößen entsteht eine vergleichbare Reduzierung erst, wenn mehrere Planetspindeln entfernt werden. Je geringer die Zahl der Planetspindeln wird, desto größer wird der Abstand der Panetspindeln in Umfangsrichtung und desto leichter wird es für die Schmelze, zwischen den Planetspindeln zurück zu strömen. Die Reduzierung der Planetspindelzahl findet bei 3 Planetspindeln eine Grenze.
• Außerdem läßt sich die Rückströmung/Leckströmung sehr vorteilhaft durch Veränderung der Planetspindelzahl beeinflussen. Vergleichbare Möglichkeiten finden sich an einem Einschneckenextruder oder einem Doppelschneckenextruder nicht.

This can be achieved in different ways with planetary roller extruders. This is preferably done on the planetary spindles:

• -the number of planetary spindles (number of rotating planetary spindles) can be reduced / changed. Depending on the size of the planetary roller extruder / planetary roller extruder module / section, the number of planetary spindles can be up to 24 and be more. In the case of smaller sizes, the number of planetary spindles even 5 or 6th be. The reduction of the number of planetary spindles by 1 already includes a significant reduction for smaller sizes. With larger sizes, a comparable reduction only occurs when several planetary spindles are removed. The smaller the number of planetary spindles, the greater the distance between the panet spindles in the circumferential direction and the easier it is for the melt to flow back between the planetary spindles. The reduction in the number of planetary spindles takes place at 3 Planetary spindles a limit.
• In addition, the return flow / leakage flow can be influenced very advantageously by changing the number of planetary spindles. There are no comparable possibilities on a single-screw extruder or a twin-screw extruder.

After each reduction / change in the number of planetary spindles, the planetary spindles are redistributed around the circumference of the central spindle in order to ensure an even distribution. With even distribution, the central spindle is better supported in the housing and the risk of planetary spindles jumping over is reduced. Skipping usually leads to an immediate blockage of the extruder and a broken tooth. At least the even distribution of the planetary spindles reduces wear.

The reduction of the planetary spindle / change in the distribution of the planetary spindles is carried out when the extruder is at a standstill after the nozzle has been dismantled. In addition, the number of planetary spindles is reduced / the distribution is changed in modules / sections.

Not only is the nozzle removed, but also all modules / sections that follow the module / section in the flow direction of the melt, the planetary spindles of which are to be reduced and redistributed. However, the central spindle remains. If the return flow in the planetary roller extruder is to be reduced, this is preferably done by increasing the number of planetary spindles. To increase the number of planetary spindles, more planetary spindles are arranged between the central spindle and the surrounding housing. The increase in the number of planetary spindles is prepared / completed with the same measures that are also taken for reducing the number of planetary spindles

Inexperienced operators are advised to use a template for redistribution, which is pushed onto the central spindle. At the points where the planetary spindles are pushed between the central spindle and the surrounding housing, the template has bores with a diameter that is equal to the planetary spindle's diameter, plus a generous amount of play. As a result, the planetary spindles can easily be pushed at the bores between the central spindle and the associated housing and thereby occupy a distance from one another which is at least approximately the same.

Experienced operators can dispense with the use of a template.

• Die Zähnezahl wird reduziert. Die Zähnezahl kann bis auf drei Zähne, sogar bis auf eine Zahl reduziert werden. Das kann nachträglich durch Herausarbeiten von Zähnen an den Planetspindeln erfolgen. Die Entfernung der Zähne erfolgt vorzugsweise durch Fräsen und einer anschließenden Feinbearbeitung durch Schleifen. Die Planetspindeln können auch sofort mit den Zähnen hergestellt werden wie die Planetspindeln, an denen nachträglich Zähne entfernt worden sind. Vorzugsweise sind die verbleibenden Zähne gleichmäßig am Umfang der Planetspindeln verteilt. Auch bei nur einem Zahn erfahren die Planetspindeln noch eine ausreichende Führung und Abstützung in der Außenverzahnung der Zentralspindel und der Innenverzahnung des Gehäuses. Das wird dadurch bewirkt, dass jeder Zahn sich über der Länge der Planetspindeln mehrmals schraubenförmig um die Planetspindeln herumwindet.

The return flow / leakage flow can also be influenced with a reduced number of teeth. Contemporary planetary roller extruders have involute teeth that are also designed as helical teeth. Advantageously, their teeth can be changed considerably. The unchanged toothing of planetary spindles is called normal toothing. Various possible changes are described below. Advantageously, the planetary spindles described below with modified toothing are all easily interchangeable with one another and with planetary spindles with normal toothing. By changing the essential effects of the planetary spindles can be increased or reduced according to choice. The interchangeability of the planetary spindles on the planetary roller extruder is an extreme advantage that cannot be found in a comparable form in single-screw and twin-screw extruders. For the advantageous exchange or change of the return flow / leakage flow by exchanging the planetary spindles, different versions of the planetary spindles are available:

• The number of teeth is reduced. The number of teeth can be reduced to three teeth, even down to one number. This can be done later by carving out teeth on the planetary spindles. The teeth are preferably removed by milling and subsequent fine machining by grinding. The planetary spindles can also be produced immediately with the teeth, like the planetary spindles from which teeth have been subsequently removed. The remaining teeth are preferably evenly distributed over the circumference of the planetary spindles. Even with only one tooth, the planetary spindles still experience adequate guidance and support in the external toothing of the central spindle and the internal toothing of the housing. This is caused by the fact that each tooth winds helically around the planetary spindles several times over the length of the planetary spindles.

The height of all the teeth of the planetary spindles can also be reduced if sections remain on the planetary spindles which give the planetary spindles sufficient guidance. The tooth height is preferably reduced by turning on a lathe or by milling on a milling bench.
The guide sections preferably have normal toothing (unchanged toothing) with an advantageous guide effect and are preferably located at the ends of the planetary spindles. In addition, it is advantageous to combine such planetary spindles with completely normal toothed planetary spindles in an extruder so that the normal teeth push or prevent all input material from the gaps between the teeth of the central spindle and the gaps in the teeth of the housing during the rotation around the central spindle Used material collects in tooth gaps and cakes there. This can be called brushing the gaps between your teeth.

Preferably not all teeth of the planetary spindles are reduced in height. At least one tooth retains its original height. This can give the planetary spindles guidance / hold in the external toothing of the central spindle and the internal toothing of the housing independently of normal toothed planetary spindle ends or in addition to normal toothed planetary spindle ends. In addition, the teeth on the planetary spindles, which are left at their original height, also clean the tooth gaps on the central spindle and clean the tooth gaps on the internal toothing of the housing.

The reduction in height of the teeth can be done, as with the complete removal of teeth, for example by milling and subsequent fine machining by grinding.

The web height is preferably reduced by at least 20%, even more preferably by at least 40% and most preferably by at least 60%.

It is also advantageous if the height-reduced / flattened teeth are rounded on the emerging new head. This improves the flow behavior of the input material when the input material is displaced into the corresponding tooth gaps of the central spindle and the corresponding tooth gaps of the internal toothing of the housing.

The webs of the planetary spindle teeth can be completely or partially interrupted at regular intervals or at irregular intervals. A uniform interruption arises, for example, when the planetary spindles are toothed again in opposite directions after the normal toothing has been produced. This leads to a nub structure on the planetary spindle surface. This is why such planetary spindles are also called knob spindles.
The opposing toothing goes to the bottom of the tooth gaps.

If the opposing toothing is cut less deeply into the planetary spindles, the result is a different planetary spindle surface with more conveying effect.

A uniform interruption is also created if ring-shaped circumferential grooves are machined into the planetary spindles at regular intervals. These planetary spindles are called hedgehog spindles.
The grooves are usually incorporated down to the tooth base.
However, the grooves can be machined less deeply in order to achieve other properties.

Likewise, the toothing can be varied by changing the multiple threads of the opposing toothing. This means that planetary spindles with a different number of teeth can be used. You can choose between planetary spindles from which more or fewer teeth have been removed.

The normal toothing has, depending on the tooth module / tooth dimensions and the pitch circle diameter of the toothing, a certain number of teeth running around the pitch circle diameter. These teeth wind parallel to each other around the planetary spindles and contain the multiple threads of the planetary spindles.

The knobs described above are created with the same opposing toothing. However, teeth can be cut into the normal tooth system at a greater distance than with the normal tooth system. Then there are no knobs, but webs, because the teeth of the normal toothing are interrupted at greater distances.

The reduction in the number of planetary spindles and the reduction in the number of teeth on the planetary spindles can occur together or individually. The same applies to a bypass. The bypass can occur alone or together with the reduction in the number of planetary spindles and / or the reduction in the number of teeth.

The measures described above have in common that openings are created in the planetary roller extruder through which the melt can flow back, which is currently not required for 3D printing. This includes an intentional leakage flow. The backflow / leakage flow continues until the melt is again taken up by the planetary spindles and conveyed in the direction of the nozzle. If there is still no melt for 3D printing or only a small amount Amount of melt is removed for 3D printing, the melt cycle starts again.

When melt is discharged from the nozzle for 3D printing, new material is fed into the extruder. This can be done continuously or at intervals or as required depending on the above measurements.

A particularly advantageous form of an extruder for 3D printing results from a vertical / vertical arrangement of the planetary roller extruder, as shown in FIG DE19534813 C2 is shown and described. The housing of the vertically / vertically arranged extruder can have a generous cavity at the upper end, in which even difficult input material can easily collect. The planetary spindles preferably protrude at least partially into the cavity, so that the planetary spindles grip the feedstock and can pull it into a planetary roller extruder module / planetary roller extruder section arranged vertically / vertically underneath. The planetary spindles mesh with the external teeth of a central spindle and the internal teeth of the extruder module housing / extruder section housing.

A filling level probe is located in the cavity provided above, which immediately gives a signal to replenish feed material if the filling level falls below a selected level.

• -Gewichtsmessung des Extruder. Bei großer Füllung des Extruderhohlraumes mit Schmelze ergibt sich ein anderes Gewicht als bei geringer Füllung des Extruderhohlraumes mit Schmelze
• -Ulltraschallmessung am Extruder. Bei großer Füllung ergibt sich ein anderes Signal als bei geringer Füllung
• -Widerstandsmessung durch Anlagen einer elektrischen Spannung. Bei großer Füllung ergibt sich ein anderer Widerstand als bei geringer Füllung. Entsprechendes gilt für einen elektrischen Stromfluß durch den Extruder.

Other methods of level measurement are also suitable. This includes

• -Weight measurement of the extruder. If the extruder cavity is largely filled with melt, the weight is different than if the extruder cavity is only slightly filled with melt
• -Ultrasonic measurement on the extruder. With a large filling a different signal results than with a low filling
• -Resistance measurement by applying an electrical voltage. With a large filling there is a different resistance than with a small filling. The same applies to an electrical current flow through the extruder.

The feed material is heated and melted in the planetary roller extruder module / section and conveyed to a nozzle. Heating the module housing in the intake area is helpful for warming up. After the initial heating, the deformation of the feedstock leads to further heating and melting on its further way down. The nozzle is optionally conical and has a tapered discharge end. This shape is streamlined. The length of the nozzle in the axial direction is preferably designed as a function of the diameter of the nozzle. A small length is provided for small diameters and a long length for large diameters. The outlet opening of the nozzle depends on the width of the melt strand / thread / band to be discharged. The inlet opening of the nozzle depends on the size of the extruder with which the material intended for printing is melted. The slimmer the cone, the better the flow of the nozzle. However, a nozzle without a conical shape can also be used. There is no conicity if the nozzle is formed by a cylindrical bore in the cylindrical end wall of the extruder on the outlet side.

In the exemplary embodiment, the nozzle can be displaced in the axial direction of the extruder. The displaceability serves to open the nozzle completely or partially or to close it completely or partially.

Optionally, the nozzle is held in a straight line for this purpose. For this purpose, a rail or a profile can be provided which runs parallel to the nozzle axis. Optionally, several rails or profiles can also be provided, which run parallel to the nozzle axis at a distance from one another. When using several profiles, simple round profiles can be used as guides.
When using a single rail or profile, a cross-section is preferably chosen for the rail or profile that prevents the nozzle or its holder from rotating about the longitudinal axis of the rail or profile, but allows movement in the longitudinal direction of the rail or profile . The nozzle or its holder can encompass the rail or the profile or engage in the rail or the profile.

Optionally, the guide also has the shape of a slide. The slide can be a linearly moved slide or a rotary slide. The rotary valve can be rotatably mounted on a bolt or axle or pin or in some other way. Such a storage can also be a ring or collar or cylinder which surrounds a disk-shaped slide on the outside.

The guide can also be formed by a swivel arm. Then the nozzle is held with the swivel arm.
It is then advantageous if the nozzle center axis in the closed position is aligned with the center axis of the central spindle tip. The closed position is the position in which the nozzle rests closing on the central spindle tip. To open the nozzle, the nozzle is lifted off the central spindle tip with the swivel arm. The influence of a change in the central axis position of the nozzle with respect to the central axis of the central spindle tip is negligible.

The linear nozzle movement can also be done with the help of a robot.

Known robots have an arm that is articulated several times so that movements can be carried out in any direction. Of course, a robot can do much more than just move in a straight line. Its construction and its control are correspondingly complex. Due to the large number of commercially available robots and the associated series production, such a robot is still cheaper than another nozzle guide that is produced individually.

An electrically controlled drive that reacts to short control pulses is provided for moving the swivel arm. When the nozzle is open, melt flows as a melt thread or as a melt ribbon or melt strand onto a work table which can be moved transversely to the central axis of the central spindle tip and at the same time in the direction of the central axis of the central spindle tip. The movements of the work table and the nozzle are controlled in such a way that a 3D molded part is created with the emerging melt thread / ribbon / strand.

For the application of the printing according to the invention to the structure / building, a nozzle with several, changeable outlet openings is advantageous. With large outlet openings, large quantities of melt can be discharged and a large construction output can be achieved
At the same time, the nozzle can be provided with smaller outlet openings, for example for thinner melt threads.
The exchangeability of the various outlet openings is an advantage. The outlet openings are preferably changeable during a manufacturing process in order to achieve an adaptation to a desired change in the tapes / threads / strands and / or a change in the outlet capacity. The change in the outlet openings can take place with other boundary conditions such as pressure and temperature remaining the same or with a simultaneous change in one or more other boundary conditions.

Such a nozzle can be formed by a slide which is provided with an adjusting drive and is controlled by computer. The slide can have a cylindrical shape and sit in a housing with a bore that fits the slide. The slide has various (small and large) through bores, which run at a distance from one another transversely to the longitudinal axis of the slide. The slide can also have nozzle openings inclined to the central axis of the extruder. Nozzle openings with different inclinations can also be provided. With the nozzle openings inclined in this way, the melt threads and melt strips / melt strands can also be deposited at a different location than with a nozzle opening whose axis is aligned with the central axis of the extruder.

The slide sits on or in the nozzle and can be moved and rotated transversely to the nozzle axis. By moving the slide, for example by moving the slide in the longitudinal direction, the appropriate hole can be brought into position. The nozzle can be closed or opened by turning the slide.

Optionally, the nozzle can also be combined with a ball valve as a control valve for closing and opening. The nozzle can also be designed as a ball valve. There is a ball with a passage opening in the ball valve or in the nozzle. By turning the ball, the passage opening is made smaller or closed or opened. The sphere can also perform other tasks. For example, several different passage openings can be made in the ball. These passage openings are made at different points on the ball and directed through the center of the ball. It is advantageous if all the bores lie on a circle on the circumference of the ball, so that different passage openings can be brought into the melt flow by rotating the ball. This can be used to adjust the melt flow and to shape the melt strand. Instead of the ball, a conical closure body can also be arranged in the tap or in the nozzle, which is provided with one or more passage openings in the same way as the ball, but is easier to manufacture than the ball and easier in sealing contact with the surrounding area Coat can be brought.

Optionally, a robot arm can also be used as a nozzle, in that the robot arm is provided with a passage opening for the melt and is mounted on the outlet opening of the extruder so that the melt flows through the robot arm and can be directed to any point by the robot arm.

Optionally, the nozzle can also be formed by a rotatable and / or pivotable and / or displaceable cover which is provided with a large number of nozzle openings which can be brought into position by rotating, pivoting or sliding the cover in front of the extruder outlet. Smaller and larger nozzle openings and nozzle openings with different cross-sectional shapes are provided. This means that the emerging melt strand / band / thread can be given a different cross-section, so that, for example, in one case Melt threads and, in the other case, melt bands arise. As in the case of the slide, the nozzle openings can be aligned with the center axis of the extruder or run at an angle to it.

The rotatable and / or pivotable cover can be guided and held in the middle and / or on the outer edge. In the middle, the guide and bracket can be formed by a bolt / tenon / mandrel / axle. At the edge, the guide and holder can be formed by a ring / collar / cylinder. The extruder outlet is opened and closed by pivoting or rotating a closed cover part in front of the extruder outlet.

The nozzles are optionally heated or unheated. Unheated nozzles are dependent on the melt in the nozzle remaining meltable or the nozzle being cleaned after each melt surge / melt flow. The melt remains liquid in unheated nozzles if an interruption in the melt flow does not result in cooling to below the melting temperature. The cooling down to solidification of the melt is time-dependent and dependent on the initial melt temperature. In the event of a short interruption, the flowability of the melt is ensured. The usual melt temperature during extrusion operation is at least 5 degrees Celsius, preferably at least 10 degrees Celsius, even more preferably at least 15 degrees Celsius above the melting temperature and most preferably at least 20 degrees Celsius above the melting temperature at which plasticization occurs.
It is advantageous to set the melt temperature during the extrusion operation so that an interruption time of at least 2 seconds, preferably of at least 4 seconds, even more preferably of at least 6 seconds and most preferably of at least 8 seconds is possible. This simplifies the handling of the device considerably.

As an alternative or in addition, heating of the nozzle is provided. If the nozzle is heated, the cooling of the melt in the nozzle can be slowed down in the event of an interruption, so that a longer interruption is possible. In extreme cases, the heating can be designed in such a way that the melt does not cool down in the nozzle. However, an interruption is preferably kept short in order to avoid negative effects of the temperature on the molecular structure.

Stepping motors are advantageous for the movements of the nozzle. Modern motors have a walking speed of up to 400 steps per second with high accuracy.

Optionally, there is also a nozzle that can be swiveled in all directions in front of the extruder outlet. The nozzle consists of a connection part to the extruder outlet, a joint and a nozzle outlet part. The melt flows through the connection part, through an opening in the joint and through the nozzle outlet part.
Optionally, the joint can at the same time form the connection to the nozzle outlet and / or the nozzle outlet part.
In addition, the joint can be designed as a ball joint.

A section of a hollow sphere can also be used as the nozzle. Hollow spheres have a spherical shape on the outside and a spherical cavity on the inside with a common center point in relation to the outer shape, so that there is a spherical jacket. A section of this hollow jacket is optionally used.

It can be provided here that the section of the hollow jacket slides on the end of a melt feed line which, at the contact surface with the section, has the same radius as the section of the hollow jacket.

The section of the hollow jacket is provided with various nozzle openings. The nozzle openings are distributed over the surface of the section. By shifting the section on the end of the melt feed line, a different nozzle opening can be brought into an aligned position with the opening of the melt feed line or a closed part of the hollow jacket section can be brought to close the melt feed line before it opens.

The movement of the hollow jacket section can be controlled with the aid of power pistons. For example, three power pistons can be arranged in an articulated manner distributed uniformly on the circumference of the hollow jacket section, so that they can move the hollow jacket section in any direction and brace it with the head of the melt feed line in the respectively desired position.

The hollow jacket section is optionally supported with a guide on the side facing away from the melt feed line. The guide facilitates the movement of the hollow jacket section.

The smallest possible adjustment paths are advantageous for the slide and hollow jacket sections, which can move other nozzle openings in front of the melt feed line. This applies in particular to a point-by-point relocation of the melt. The adjustment path between two adjacent slide positions or hollow jacket section positions is preferably less than 10 mm more preferably less than 8mm and most preferably less than 6mm.

The emerging melt usually meets melt that has already cooled completely or partially. So that the prerequisite for connecting the new melt with the previously laid melt is given, the previously laid melt can be heated at the contact surface before the new melt hits. This can be done by means of an electrically operated heating wire, which is optionally attached to the nozzle and protrudes just above the surface to be heated.

Another possibility for reheating the previously laid melt is to apply hot air to the contact surface. The hot air can advantageously exit at some distance from the contact surface. This is harmless to other areas of the molded part and facilitates the supply of hot air.

The contact surface can also be heated by touching a heated object that slides or rolls on the melt threads / melt bands / strands that have already been laid and cooled.

When processing baked goods and / or confectionery in the extruder, the question arises whether and how the extruder can be cleaned, at least after every long interruption in operation and after every significant change in the input material. Cleaning is indispensable for baked goods and confectionery products because the baked goods and confectionery products can spoil, so that spoiled residues can contaminate the new input material when the extruder is restarted. This means that a longer interruption of operation with a necessary cleaning sequence occurs if there is a possibility that the input material could have spoiled over time, i.e. it could no longer be suitable for consumption. It depends on the nature of the feed and the circumstances. The circumstances are particularly temperature and humidity.

Various cleaning agents are conventionally available and fed into the extruder.

In the DE202008017267 as well as in the EP2196529 as well as in the DE102008061171 a mixture of an artificial and / or natural mineral with an organic acid and / or an inorganic base is proposed as a cleaning agent.

• Talkum, Kreide, Bariumsulfat, Silikate, Kieselsäure, Glasfasern, Glaskugeln, Aluminiumoxid, Magnesiumhydroxid, Aluminiumhydroxid, Aluminiumnitride, Litiummineralse, Nanodiamanten, Nanopartikel wie z.B. Schichtsilikate, Kaolin, Wollastonit, Bentonit

The following minerals are suggested:

• Talc, chalk, barium sulfate, silicates, silica, glass fibers, glass spheres, aluminum oxide, magnesium hydroxide, aluminum hydroxide, aluminum nitrides, lithium minerals, nanodiamonds, nanoparticles such as sheet silicates, kaolin, wollastonite, bentonite

• Dialkylmalonsäure, aliphatische Mono-, Di- und Tricarbonsäuren, Stearinsäure, Tartronsäure, Zitronensäure, organgisch Alkylsulfonsäuren und/oder organsiche phenylsubstituierte Sulfonsäuren

The following organic acids are proposed in this publication:

• Dialkylmalonic acid, aliphatic mono-, di- and tricarboxylic acids, stearic acid, tartronic acid, citric acid, organic alkyl sulfonic acids and / or organic phenyl-substituted sulfonic acids

• Thermoplastische Styrol-Olefin-Blockcopolymere, Styrol-Ethylen-Ethylen-Propylen-Styrol-Blockcopolymere, Styrol-Ethylen-Butadien-Styrol-Blockcopolymere und diverse andere Polymere, auch Kautschuke

The following are suggested as bases:

• Thermoplastic styrene-olefin block copolymers, styrene-ethylene-ethylene-propylene-styrene block copolymers, styrene-ethylene-butadiene-styrene block copolymers and various other polymers, including rubbers

In the EP453859 an acrylonitrile / butadiene / styrene polymer is proposed as a cleaning agent, possibly mixed with abrasion particles, emulsifiers and surfactants.

In DD239355, plastic molding compounds are proposed for displacing residual materials that have remained in the extruder.

All of these cleaning agents assume that the extrusion system is not dismantled for cleaning. Considerable waste is better accepted.

In a further development of the above invention, a different approach is taken for a necessary cleaning. This approach provides a particularly advantageous exchange of the dismantled, soiled extruder parts for clean extruder parts.

By changing the extruder parts, waste is minimized and considerable operating time is saved. This includes the small size of the extruder parts, which allows cleaning in a commercially available dishwasher with commercially available detergent. Dishwasher-safe are extruders with module / section lengths of at most 500 mm, preferably at most 400 mm and even more preferably at most 300 mm.

A quick-change system is also an advantage.

The invention is based on an older proposal according to DE102019004945.1 at.

The older proposal assumes that the housings belonging to each extruder module / extruder section have a flange at each end of the housing for attachment to one another and to the associated gear unit.

Each flange allows a screw connection to the flange at an adjacent end of the housing. Screws / nuts and anchors are used for the screw connection. The screws and anchors can grip through corresponding screw holes or slots in the flanges. The number of screws is conventionally at least 6. Depending on the size, the number of screws is multiplied. The problem with such a large number of screws is the uniform tension. The operating people try to help themselves with wrenches that can be used to set the torque. Nevertheless, each time a screw is retensioned, it affects the tension of neighboring screws. This is particularly true when the flanges to be braced are spaced apart. The spacing is created by intermediate pieces or ring constructions that are arranged between the two ends of the housing.

The ring construction can have different tasks. The thrust ring is usually part of the ring construction.

As a rule, the tasks also include the centering of the two housings to be connected to one another. The ring construction engages in corresponding openings of both adjacent module ends / section ends for centering.

The older proposal provides for a clamp connection between the flanges instead of the conventional screw connection, which requires neither screw holes nor slots on the flanges. For clamping, the flanges can be gripped with clamps at the edge.

Optionally, the clamps are a clamping ring that is at least half divided. The ring halves can be connected to one another in an articulated manner at one end. At the other end, the ring halves are clamped together.

The clamping ring comprises the flanges on the outer edge with a groove which tapers in cross section to the groove base. When the ring halves are clamped, the flanges initially come into contact with the lateral groove surfaces of the clamping ring. There is a play in the radial direction of the clamping ring for the edge of the housing flange in the groove, so that the edge can move further into the groove in the radial direction. Further tensioning of the ring halves causes a corresponding pressure of the lateral groove surfaces on the flanges to be braced with one another. The clamping ring acts like a wedge. However, the clamping ring does not drive anything apart, but rather the flanges are pressed against one another because the groove surfaces, which act as wedge surfaces, are directed against one another. On a normal wedge, the wedge surfaces point away from each other.

The pressure created by the clamping ring is equal to the clamping force with which the flanges are pressed against each other at a joint between two modules / sections.

The smaller the wedge angle, the stronger the clamping force is translated into a clamping force.
The wedge angle and the associated translation of the clamping force are preferably determined empirically with a few tests. Clamping rings with different groove openings are used in the tests. Even more preferably, the one selected from the clamping rings whose center has the smallest distance from the center of the extruder when the desired clamping force is reached. The center of curvature of the ring half / section is regarded as the center.

Preferably, only a single screw is actuated during clamping, while in conventional planetary roller extruders a comparatively large number of screws with the problems explained above are actuated.

In addition, the connection of two sections / modules can be established much faster in this way than in a conventional way with many screws.

The same applies to loosening the connection. The older proposal is therefore particularly suitable for extruders with only short-term operating times with necessary modifications or with maintenance measures and dismantling and subsequent reassembly. The same applies to input materials and other reasons that lead to repeated business interruptions. Shorter assembly and disassembly times are generally advantageous when it comes to shortening a business interruption.

That is why the older proposal came about through the development of a laboratory extruder.

According to the older proposal, the clamping connection should preferably be small-sized, for example the size 30th or 50 Find application. With planetary roller extruders, the size is derived from the pitch circle diameter of the internal gearing of the housing. The internal gearing is not on modern planetary roller extruders provided more directly in the housing, but in a socket that is shrunk into the housing. The socket has depressions on the outside that run like threads. The depressions form channels for a temperature control medium. The thinner the bushing, the better the temperature of the planetary roller extruder can be, that is, it can be heated and cooled. The applicant's sockets allow cooling down to minus 100 degrees Celsius and heating to 350 degrees Celsius. This temperature control performance does not have to be exhausted for the intended production of baked goods and confectionery goods. However, the future may be different. For example, there may be a need for strong heating if the melt in the extruder should at least be baked in order, for example, to form an outer skin on the emerging tapes / threads / strands, which has the intended contour when the tapes / threads / strands are laid preserve.

In contrast, the speed at which temperature changes can be carried out on the melt, which is possible with the sockets of the applicant, is of current importance. The faster temperature changes can be carried out, the more precisely the production of the baked goods / confectionery goods can be regulated / controlled.
A small thickness of the internally toothed housing bushing contributes to the good temperature control of the print heads according to the invention. With the small sizes relevant here, housing bushings can be used that have a thickness of 1 to 1.5 mm at the thinnest point.

According to the older proposal, the extruder is preferably also provided with involute teeth and manufactured with a tooth module of less than or equal to 1.5. The tooth module determines important dimensions of the toothing. The tooth height, for example, results from the tooth module.

There are different types of teeth. One of them is the involute toothing. The involute toothing defines the shape of the tooth. The number of teeth on the planetary spindles is preferably at least five.

The planetary spindles are preferably distributed evenly in the gap between the central spindle and the surrounding housing or surrounding bushing. With a little practice, the operators manage the even distribution by hand. Where the exercise is lacking, a template can be used to distribute the planetary spindles. A sheet metal with a number of bores that corresponds to the down payment and arrangement of the planetary spindles has proven itself.

The modular (section-wise) construction of a planetary roller extruder has considerable advantages, especially for the small sizes required here, because a length of 500 mm, preferably 400 mm and even more preferably 300 mm should not be exceeded here. In addition, the various extruder modules / sections can easily be exchanged for extruder modules / sections of a different design. Another design results with special functions. Special functions also result in a different design. There are extruder modules / sections for filling in the feedstock. These modules / sections are called filler parts. There are special filling parts for normal grain size. There are other filler parts for fine-grained material and filler parts for material that tends to stick.

There are filling parts in which the feed material is separated from the entrained air.

There are special filling parts for feeding in additional material at a distance from the first feeding point.

There are special filling parts for adding liquid ingredients.

There are extruder modules / sections with a degassing. There are extruder modules / sections for rapid melting of thermoplastic feedstocks as well as extruder modules / sections for rapid heating of the feedstock.

There are extruder modules / sections for adding small amounts of fine-grained or powdery ingredients.
There are extruder modules / sections for connecting a side arm extruder. There are extruder modules / sections with measuring devices.
There are extra modules / sections to even out the melt flow.

When the length is the same, one often speaks only of modules. In the case of different lengths, one often speaks of sections. There is no clear division in the professional world. Modules / sections of the same length facilitate replacement. Then there is no longer so many modules / sections to be kept available for replacement.

It is also advantageous to use different groups of modules / sections, the modules / sections of a group all being of the same length.

In such groups, it is advantageous if the modules / sections of one group are twice the length of the modules / sections of the other group. Then a longer module / section can be exchanged for two shorter modules / sections.

When replacing, the aim is to continue using the previous central spindle so that the central spindle does not need to be adjusted.

The modules / sections preferably have a minimum length of 100 mm.

The smaller the housing bore to be internally toothed or the opening to be internally toothed in the housing bushing, the more difficult it is to manufacture. The size of the hole also affects the spark erosion of the bores, because with spark erosion a pilot hole is first made in the material. A voltage is then applied to the electrode and the housing or the socket under a dielectric, so that sparks emerge from the housing or the socket and thereby cause material to be removed. The dielectric is oil or deionized water. Due to the heat generated, gas is generated during spark erosion, which rises in the dielectric. This makes the material removal point continuously gas-free. The gas cannot hinder the eroding process. The smaller the pilot holes, the more difficult it is for the gas to climb past the electrode.
According to the invention, the resulting gas is also extracted by suction. The housing bores for longer modules can also be spark eroded with the extraction system.

The clamps suggested above for changing the modules / sections are optionally composed of two halves.

The halves are optionally created from a closed clamping ring to which bearing points / holding devices are attached, preferably welded, in the initial state.

In one embodiment, joint parts are created on one side of the clamping ring. On the opposite side of the clamping ring, bearing points / holding devices are provided which interact with a tensioning screw / anchor. A bearing point for the articulated mounting of the clamping screw / anchor can be provided on one side of the clamping ring and a holding device can be provided on the other side of the clamping ring. The holding device can, for example, have the form of two spaced-apart cams. The tensioning screw / anchor is then pivoted between the cams so that the tensioning screw / anchor can grip behind the cams with a screw nut and thus come into the tensioning position when the ring halves have been brought into position on the associated flanges.

The pivotable clamping screw / anchor can have a T-shaped construction, the shape consisting of a screw part / anchor part running transversely to the extruder longitudinal axis and a bearing part / bearing bolt running parallel to the extruder longitudinal axis. With the bearing part / bearing bolt, the clamping screw engages in the joint parts of the bearing point arranged on the side of the clamping ring.

The screw part / anchor part is preferably provided with an eyelet on the bearing point side. The eyelet is provided instead of the bearing part / bolt running parallel to the longitudinal axis of the extruder. In the operating position of the clamping ring, the eyelet is penetrated by a bolt which engages in the joint parts explained above. It is advisable to either lock the bearing part / bolt in the hinge points or to lock it in the eyelet. This prevents the bearing part / bolt from running out to the side.

A single cam can also be sufficient as a holding device if a clamping bracket is used instead of the screw part / anchor part. The clamping bracket can, for example, have a closed O-shape or have an open C-shape. Like the screw part / anchor part, the clamping bracket can be arranged in an articulated manner on the associated end of the ring half and, when pivoting in the operating position, encompass or overlap a cam on the adjacent end of the ring half. After reaching around or over, the tension according to the invention can be brought about by a screw provided in the bracket or by a lever. A toggle lever, which remains self-locking in the clamping position, is also advantageous.

Optionally, a clamping screw / anchor can also be used, which, unlike the clamping screws / anchor described above, can be removed from the clamping ring after each release. Such screws can have the same shape as the articulated clamping screws / anchors explained above. The connection / detachability is achieved with such tensioning screws / anchors in that, instead of the arrangement of the screw part / armature part running parallel to the longitudinal axis of the extruder, a cam with an open bearing shell is provided in a bearing bore. The clamping screw / anchor is then inserted into the bearing shell with the screw part / armature part running parallel to the longitudinal axis of the extruder and initially held in contact with the bearing shell when pivoting by hand until the clamping screw / armature has reached the clamping position. This does not require any skill worth mentioning and is easily reasonable for the operators. When the tensioning begins, the tensioning screw / anchor remains in the tensioned position without any further support.

The joint provided above between the ring halves defines the position of the ring halves. For this purpose, the ring halves can be manufactured with sufficient accuracy. For example, a closed clamping ring can first be manufactured with all of the parts described above and the groove that tapers towards the bottom of the groove can be machined, for example on a lathe. But it is also possible to mill the groove. The lateral groove surfaces are then preferably ground in order to reduce the friction values on the groove surfaces. Optionally, a plastic layer can also be provided on the groove surfaces, with which very low friction values can be achieved.

The low friction is advantageous for the function of the clamping ring / halves / sections according to the invention. The clamping ring / halves / sections overlaps the edges of the flanges to be braced with one another. When the clamping ring / halves / sections are clamped, the edges of the flange to be clamped together slide on the lateral groove surfaces. It is advantageous if the flanges are beveled at the edges so that the friction surfaces of the flange edges run as parallel as possible to the opposite side surfaces of the groove. As parallel as possible, according to the invention, a deviation of at most 20 degrees in the inclination with respect to the inclination of the side surface, preferably a deviation of at most 10 degrees, even more preferably a deviation of at most 5 degrees and most preferably a deviation of at most 2 degrees.

It is also advantageous to round the edges of the flanges at the contact surface with the clamping ring / half / section. The rounding preferably has a radius of at least 3 mm, even more preferably a rounding with a radius of at least 6mm and most preferably a rounding with a radius of at least 12mm.

The clamping ring according to the invention can be divided into halves or sections before the processing described above. After that, precise machining of the halves or sections is also possible, in particular with digital control of the machining devices.

Machining includes in particular the machining of bearing surfaces, bearing surfaces, grooves with contact surfaces, clamping surfaces. However, precise machining is also possible with simple equipment and little effort if the separation into halves and sections takes place after machining. A first processing can then create positions defined with templates, for example, which are supported / oriented on the first processing surface. Samples of already manufactured clamping rings / halves / sections are also suitable as templates.

The clamping ring can be separated by sawing and other conventional cutting separation systems. State-of-the-art separation with flame cutting, plasma cutting, spark erosion, laser cutting, water jet cutting, and arc cutting can also be used.

When separating the clamping ring, an exact fit of the ring halves on the edges of the flanges to be connected is possible regardless of the width of the cut.
Advantageously, this can also be used to manufacture ring sections with a substantial distance from one another instead of the ring halves. The distance refers to the distance between adjacent ends in the circumferential direction.

The clamping rings can also be divided into more than two sections. With the exception of two opposing section ends, all other opposing section ends are preferably connected to one another in an articulated manner, so that a link chain is created which can be placed around the housing flanges to be connected to one another. This articulated connection of the sections can take place after submission of the articulated connection described above.
The connection / bracing of the ends of the link chain according to the invention can take place as in the case of the connection / bracing of the ring halves described above.

Optionally, individual or multiple connections of sections can also be made using multiple joints, in particular double joints. In this case, connections with intermediate pieces between two adjacent section ends are regarded as double-joint connections according to the invention, the intermediate pieces being connected in an articulated manner to each associated section end. The intermediate pieces can be in one piece or in several pieces. An example of a multi-part design can be spacers that consist of bolts and straps. The bolts can be positioned in the bearing bores of the halves / sections and have a length such that they protrude from the bearing bore at both ends and can be connected to one another at the protruding ends via the tabs.

When the housing is braced according to the invention, uniform bracing can be brought about by conventional centering and measurement. In addition, centering can be made easier with a new type of ring construction. The novel ring construction differs from known ring constructions in that it has larger radial dimensions. The dimensions chosen are so large that the ring construction (apart from the flanges) protrudes at least over the outer jacket of the internally toothed housing bushing. As a result, the ring construction can encompass the housing bushing on the outside and thus effect the centering when the housing bushing protrudes from the housing in the axial direction or the housing is shortened / set back in the axial direction with respect to the housing bushing.

The larger ring construction results in a larger contact surface of the ring construction between the module ends. This gives the modules more stability when bracing and makes it easier to brace the ends of the housing properly.

The ring construction can also be enlarged further, at least up to the edge of the flanges to be braced together. Depending on the shape of the groove in the clamping ring, a radial enlargement beyond that into the groove of the clamping ring is also possible.

After the ring construction has been radially enlarged to over the outer casing of the housing, the ring construction can also bring about a centering by enclosing the casing casings of the two housings to be connected. For this purpose, the associated flanges can be set back with respect to the end of the housing by the amount that is required for the encircling by the ring construction.

Up to now, a larger volume of the ring construction could only be achieved by axially lengthening / enlarging the ring construction. Compared to the radial enlargement, this makes the stable and precise connection of the housing more difficult. Furthermore, as the length increases, the problem of so-called dead spaces between the central spindle and the ring structure surrounding the central spindle arises because there is an uncontrolled flow of melt. This can lead to undesirable reactions from the feedstock. This can be counteracted by narrowing the gap between the central spindle and the surrounding ring structure. However, this leads to other influences on the input material.

A stop ring is also regularly part of the ring construction. A particularly wear-resistant material is useful for the thrust ring because the planetary spindles slide along the thrust ring with high pressure during extruder operation. Ceramic disks are particularly wear-resistant, including disks with a hardened surface. Such wear-resistant disks are usually embedded in the ring structure.

In addition, the larger volume of the ring construction makes it easier to accommodate a temperature control.

The temperature control requires channels through which the temperature control medium can flow in order to effect heating or cooling as required.

A known technique provides for the channels to be assembled from at least two channel-forming rings. The cross section of a channel-forming ring can be U-shaped, while the other channel-forming ring closes the U-shaped cross section at the open end.

The temperature control medium is fed to each channel from a heating / cooling device via a line. The temperature control medium leaves the channel via another line and is fed back to the heating / cooling device. The temperature control medium is reprocessed there.

If the ring structure is to be heated, the temperature control medium is heated in the heating / cooling device in order to subsequently return the heat content to the ring structure.

In the event that the ring structure is to be cooled, the temperature control medium is cooled in the heating / cooling device and then fed back to the ring structure.

Advantageously, the lines can lead in the axial direction of the extruder through the housing flanges to be braced together into the ring structure or lead away from the ring structure and the flanges.

Measuring devices for pressure, temperature, flow rate and color can also be accommodated in the ring construction according to the invention. Measuring devices for pressure and temperature in a ring construction are known. There are holes in the ring structure that can accommodate different measuring devices. Measuring devices for the flow rate and the color are new.

• -Extruderantrieb
• -Kühlung/Beheizung des Extruders
• -Materialaufgabe/Dosierungen
• -Pumpenantriebe
• -Entgasung

The measured values of the measuring devices can be transmitted wirelessly or via suitable lines to a control which acts on all units on which the result of the extrusion depends. The aggregates include

• -Extruder drive
• -Cooling / heating of the extruder
• -Material feed / dosing
• Pump drives
• -Degasing

The ring construction can also be used to introduce solid, preferably liquid, input material.

The ring construction according to the invention is not only important in connection with the clamping ring described above, but also independently of the clamping ring described above in the case of conventional bracing of housing flanges by screwing. While when using a clamping ring the lines for the temperature control medium and / or for the transmission of measurement results to a control and / or which are preferably passed through openings in the housing flanges for material input, without using a clamping ring it is preferably provided that these lines go through the outer jacket the ring construction between the two flanges.

In both cases (with clamping ring and without clamping ring), the ring construction can be used to center the housings to be connected to one another at the same time.

For centering two module housings, even in the case of an extruder without a clamping ring, it is advantageous if the ring construction provided according to the invention between the two housing ends comprises at least the housing bushing on the outer jacket. As with the connection of two module housings with a clamping ring, provision is made for the housing socket to protrude with respect to the housing or for the housing to be set back with respect to the housing socket.

Optionally, the ring construction can also include the housings that connect to one another. Then the flanges are set back by the amount with respect to the edge of the associated housing jacket that is required for enclosing the housing jacket.

Optionally, if the housing is braced without a clamping ring, the tube construction can grip an inner collar between the two housing sockets. The inner collar preferably ends with the inner jacket of each housing socket, so that a continuous inner surface of the extruder is created at the connection point.

Particular advantages result when used on small extruders for processing granular feedstock. In the case of extruders of a smaller size, the granulate preferably contains a mixture with all the necessary mixture components. This eliminates the need for a large amount of equipment for metering the components of the mixture in the small system. Smaller systems here are extruders with an overall size of less than 70mm, preferably less than or equal to 50mm, even more preferably with an overall size of 30th .

It may also be advantageous to measure the degree of filling of the extruder and to regulate the granulate feed according to the measured values. The degree of filling can be measured at different points, for example in the filling part. In the case of an extruder constructed in modules / sections, the filling part is the first module / section in the extrusion direction into which the granulate is filled. Instead of the measurement there or in addition, a measurement can also take place elsewhere, for example in the module / section in which the feed material is present in molten form.

The degree of filling of the extruder can be measured in various ways. This can be done by positioning a measuring sensor in the jacket of the filling part. The sensor can contain any form of measurement that reacts to granules or melt. These include, for example, pressure, temperature, ultrasound and other sounds.
The degree of filling is preferably determined by weight measurement or by optical volume determination.
If the filling level falls below a predetermined level, feedstock for the melt production is added.

When measuring the degree of filling by determining the weight, favorable conditions result when the extruder is on a base / workbench. The melt consumption can be calculated from the weight. The weight measurement is preferably carried out electronically by means of a microchip.
The electronic measurement can advantageously be carried out at the same time when the base / work table is in a rest position so that the measurement results are not falsified by acceleration forces and braking forces. In addition, the effects of the acceleration forces and braking forces can also be calculated or added to the results of the weight measurement.

Advantageously, the 3D printing according to the invention for baked goods and confectionery goods can be used in individual features or with a plurality of features or in total also on the printing of other foodstuffs. This opens up new possibilities for surface design as well as for the structure of processed foods, for example.
Surfaces can be decorated, for example ornamented or provided with inscriptions or decorated in other ways. For example, a cup filling with butter, margarine or the like can be provided with a logo of the manufacturer or an inscription or an ornament.

Various exemplary embodiments of the invention are shown in the drawing.

To 1 is on a pillar 1 a swivel arm 7th pivotally attached. The swivel arm 7th carries motor and gear for a planetary roller part 2 . The planetary roller part 2 is with a feed hopper 4th provided, the one side feed opening 6th in the shape of a mouth. With 3 are the inflows and outflows for heating and cooling media.
The planetary roller part 2 has a closable outlet, which will be explained below. The planetary roller part 2 has in the usual design a housing, a central spindle and planetary spindles which, due to suitable toothing, mesh both with the central spindle and with an internally toothed bushing arranged in the housing. In the exemplary embodiment, the pitch circle diameter of the internal toothing is 30mm. The pitch circle diameter of the internal toothing also indicates the size, here the size 30th . In other exemplary embodiments, the overall size can be larger, for example 50, or smaller.

In the exemplary embodiment is the number of planetary spindles 3 . The planetary spindles are evenly distributed around the circumference of the central spindle. With a common number of 5 planetary spindles, this means a 40% reduction in the number of planetary spindles. In other exemplary embodiments, the reduction can be more or less.

There is so much distance between the planetary spindles that the extruder can continue to run with the nozzle closed or only partially open and the excess melt conveyed against the nozzle flows back as a leakage flow between the planetary spindles until the planetary spindles pick up the melt that has flowed back again and again in the direction of the nozzle support financially. If the nozzle is not yet open, the backflow / leakage flow is repeated.

The return flow / leakage flow is advantageously used in order to first achieve perfect melt mixing when the extruder is started up and the nozzle is closed, before the nozzle is opened. Then you can drive without loss of start-up. The start-up loss is easier to cope with with other extrusion processes than with the production of a 3D print on a base / work table. In the event of start-up losses, insufficiently prepared melt would be deposited on the base / workbench. Or the workbench would have to be moved out of the working direction of the nozzle and the melt loss resulting from the start-up would have to be disposed of without contamination. Contamination-free means that the system should not be contaminated by the melt that is unusable when it starts up.

Another advantage of the backflow / leakage flow arises when the leakage flow extends as far as possible to the feed hopper / filling hopper, via which the feed material is fed into the extruder. There is still a high level of friction between the solid particles there. This friction is drastically reduced by the melt flowing back. The backflow / leakage flow acts like a lubricant between the solid particles. It also improves the mix.

Advantageously, the printing according to the invention can be carried out not only with a vertical extruder but also with a horizontal extruder or an inclined extruder. Printing with a vertical / vertical extruder has the advantage that the nozzle can be brought close to the surface on which the melt is to be deposited. This facilitates accurate printing and simplifies the construction for the device. The same applies to an inclined arrangement of the base / workbench. The horizontal arrangement and movement of the base / workbench also has considerable advantages.

the 2 until 4th show un-to-scale details of the extrusion line 1 .

2 shows the feed hopper with a housing 10 that has an upper flange on the swing arm 7th is attached. The swivel arm carries a drive 5 . It has a drive shaft 12th from the drive to the central spindle of the planetary roller part 2 . The contour of the opening 6th in 2 is with 11 designated.

the 3 shows the actual funnel 15th the material feed 4th . The central spindle is with 16 the planetary spindles with 17th and 18th . The planetary spindles 17th and 18th have different lengths, so they have different heights in the funnel 15th protrude. This gives the planetary spindles an advantageous intake behavior in relation to the feed material fed into the hopper.

During operation, the rotating planetary spindles slide on a stop ring .. The housing 22nd of the planetary roller part 2 is with pivot screws on the lower edge of the feed hopper 4th releasably attached. The swivel screws make loosening and fastening easier because they can be swiveled in or brought out of engagement by swiveling.

4th shows at the bottom of the case 22nd a flange 23 that is the thrust ring 25th for the planetary spindles. The central spindle ends in a point 26th which in a screwed-on lid 24 the outlet opening 28 of the extruder. The lid 24 forms with the discharge opening and a closure 29 a nozzle. as Swivel screws are used for screw connections for the cover 28 . There is a rotatable lock on the lid 29 . The closure 29 can the outlet opening 28 of the extruder open completely or partially or close completely or partially. In the exemplary embodiment, the closure is made by hand on a lever 30th brought into the desired position. There the lock can be opened with another lever 31 be locked. It is locked by means of a screw connection.

When using the above-described system for 3D printing of molded parts with melt, the need for melt for laying a melt thread on a base / workbench or for laying on a molded part that is being manufactured is assessed by the operators and the outlet opening is assessed by hand according to the need customized. That can be quite precise, because excessive amounts of melt or insufficient amounts of melt are immediately visible in the construction progress of the molded part during printing.

The base / work table can be moved horizontally in all directions. For the horizontal movement, the base / work table in the exemplary embodiment is held in two linear guides, one of which is held in the machine frame and the other carries the linear guide. In the exemplary embodiment, the extruder is also with the swivel arm 7th on the pillar 1 Held adjustable in height. This is the swivel arm 7th on the pillar 1 guided and provided with a lifting drive, not shown.

For experiments, the base / workbench can be moved by hand in order to find the optimal placement of the melt strip for each molded part. After determining this optimal laying of the melt belt, the movement can be programmed into a control for a movement drive of the base / work table and the lifting drive of the swivel arm. In another exemplary embodiment, the control is designed in such a way that it stores the data of the manual movement and follows it up on request / pushing a button. The movement drive for the horizontal movement can be decoupled from the support / workbench for manual movement or can be coupled to the support / workbench for automatic movement. In the exemplary embodiment, the lifting drive remains coupled to the swivel arm during the manual experiments.
In the exemplary embodiment, the drive for the horizontal movement is composed of two servomotors. A servomotor is assigned to each linear guide. The servomotors are standard stepper motors. The control acts on both motors and also on the lifting motor.

For automation is in another embodiment instead of the lock 29 a slide is provided which is moved with a stepping mechanism. The stepping mechanism is actuated as required, with the need for melt being determined in a previous series of tests.

In yet another exemplary embodiment, the requirement for melt is calculated by measuring a sample piece and the stepping mechanism of the slide is controlled with the data obtained.

In yet another exemplary embodiment, the demand for melt is determined using a computer-aided 3-D design and the stepping mechanism of the slide is thus controlled.

5 shows a further embodiment of the invention. Instead of the cover that is firmly screwed to the extruder housing, there is a cover 38 provided, which is slidably disposed in the housing of the extruder. The lid 38 is guided through a bore, not shown, of the housing and at the same time sealed against undesired melt leakage. In the exemplary embodiment, the seal is formed by a membrane made of spring steel. The flexibility of the membrane is due to the necessary adjustment path of the cover 38 designed to open and close the nozzle.

The lid 38 has a computer-aided adjustment drive. The lid forms with the opening 50 a nozzle. Adjustment of the lid 38 is used to control the opening gap between the conical opening as required 50 of the lid 38 and the conical tip 35 . When the demand decreases, the gap is reduced. If the need increases, the gap is enlarged. The need is determined using a computer-aided 3D design. The data from the requirement calculation can be used to control the movable cover directly 38 be fed.

5 also shows schematically a base / workbench 39 on which the melt emerging from the opening as a thread is laid. The pad / work table 39 can be moved horizontally in all directions and also vertically. The vertical movement is provided in order to maintain the same distance between the melt outlet from the extruder and the surface on which the melt thread or the melt band is deposited as the molded part grows, despite the growing molding. In the exemplary embodiment, the surface is always located vertically / vertically under the melt outlet. When building the molded part, this is achieved by placing the base / workbench 39 with the growing molding horizontally is moved until the area in question is exactly below the melt outlet.

In the exemplary embodiment, the melt band has a width of 4 mm and a thickness of 1.5 mm. The associated nozzle is adapted to the cross-section. In other exemplary embodiments, other nozzle cross-sections are used, for example round nozzle cross-sections. In a first layer / layer, two melt strips with a width of 4mm are laid next to each other to a total width of 8mm. In the next, second layer / layer, a nozzle is used first, through which a melt band with a width of only 2mm and a thickness of 1.5mm is laid. In parallel, a melt band with the original width of 4mm and the same thickness is laid, next to it another melt band with a width of only 2mm, so that the three melt bands together also have a width of 8mm. The middle melt band of the second layer / layer overlaps the two melt bands of the first layer / layer. In the third layer / layer, two 4mm melt bands are laid next to each other, which overlap with the melt bands of the second layer / layer. The layer-by-layer laying of 2 or 3 melt bands is repeated in the next layers / layers. With the overlap, the resulting wall is given greater strength than without the overlap.

To 5 have the top 35 the central spindle and the outlet opening 50 the same taper. That’s the end 36 the tip so small that the tip 35 with the end 36 in the closed position opposite the lid 38 protrudes.

When the end 37 the top 35 The central spindle is much larger, however, so the end lies 37 the tip in the closed position opposite the lid 38 return.

6th shows with the same cover 38 and outlet opening 50 a peak 45 the central spindle with different tapers. In the case of a conical jacket shown in dashed lines 47 can end with the smaller area 48 the top 45 protrude through the outlet opening in the closed position, so that the lower edge of the conical jacket 47 touched.

When the top 45 however, a conical jacket with the conicity shown in dashed lines 46 has, it touches the top edge of the lid 38 the conical mantle 46 .

In the exemplary embodiments according to 7th and 8th becomes a same lid 38 with the same outlet opening 50 combined with other tips of the central spindle. 7th shows a peak 55 with a spherical end 56 , which in the closed position on the inner surface of the outlet opening 50 is present. The spherical shape of the tip 55 simplifies the closing movement in that a plane-parallel position of the cover to the housing is no longer required for the closing movement. This means that a pivoting movement is also suitable for closing the nozzle.

8th shows a peak 57 with a spherical end 58 due to a large diameter at the top edge of the lid 38 rests.

In the embodiment according to 9 until 13th is it a 30th iger, modular planetary roller extruder with a drive power of 1.5 kW and an extrusion capacity of 5 kg per hour, in other embodiments from 2 to 10 kg per hour. The speed of the central spindle is 1000 rpm in the exemplary embodiment.

To 10 are with 115 , 116 and 117 three planetary roller extruder modules called. Here is the module 115 with a filling funnel 118 provided for input material.

All modules are by clamping devices 120 and 121 connected with each other.

There is also a connection of the module 115 with the output journal 124 a drive, not shown, is provided. This connection is also made by a clamping device 119 educated.

The module 115 forms the so-called filling part of the extrusion line.

The modules 115 and 116 are by a clamping device 120 connected with each other. Between the modules 116 and 117 is a clamping device 121 provided as a connection.

The module 117 is with a nozzle 123 tied together. This connection is also formed by a clamping device.

9 shows various details of the extrusion line. The modules 116 and 117 are constructed the same way. They each have a casing shell 102 and externally toothed planetary spindles 110 .
In the casing shell 102 sits a housing bushing, which is provided with teeth on the inside and channel-forming grooves on the outside. The grooves are through the housing jacket 102 locked. In the exemplary embodiment, water is passed through the channels as a temperature control medium. The water is supplied via lines, not shown, through openings in the housing jacket at one end of the channel and discharged through other openings at the other end of the channel and via lines. The water is circulated. In the cycle there is a heating / cooling device with which the water can be cooled or heated if necessary.
The module 115 has a housing jacket 101 that stands out from the housing shell 102 differs by a filling opening. During operation, feed material flows through the filling opening from the filling funnel 118 into the extrusion line.
A central spindle is also included 103 to the modules 115 , 116 , 117 which extends through all modules.
In the exemplary embodiment, the central spindle is provided with a cooling system. For this purpose, appropriate bores are provided in the central spindle, through which the coolant is directed to the central spindle tip and back.

The central spindle has an external toothing and meshes with an external toothing of the planetary spindles 110 .
The planetary spindles 110 mesh with the internal teeth of the housing socket.

The planetary spindles run during operation 110 around the central spindle 103 hereabouts. The planetary spindles slide during the revolution 110 on a thrust ring, which is here by a ring construction 104 is formed. The ring construction 104 surrounds the central spindle at a distance and has a projection on each end face.

The central spindle is on the drive side 103 connected to a drive. The output journal rotates in a drive housing, which is partially shown. There is a nozzle on the outlet side of the extrusion system 107 intended.

11 shows an enlarged sectional view of the module 116 without the central spindle 103 and without planetary spindles 110 , but with housing jacket 102 and
Housing socket 136 . The channels for guiding the temperature control medium are in 11 with 130 designated. at 131 the thinnest point of the housing socket is found. In the exemplary embodiment with an extruder of the size 130 the thickness there is 1.2 mm. In other exemplary embodiments, similarly small sizes, the thickness is up to 1.5 mm. The smaller the thickness, the better the heat flow at this point.

On the casing shell 102 are housing flanges 133 and 134 molded. The housing flanges 133 and 134 are opposite the ends of the housing sleeve 136 set back so that a paragraph is created. This paragraph are the protrusions on the ring structures 104 adjusted so that the ring constructions 104 can reach around the housing bushings on this paragraph. This causes the modules to be centered on one another.

In addition, the housing jackets are fixed in the circumferential direction in relation to one another. The fixing is done by bolts, not shown, of the pipe structures 104 with which the pipe structures in bore 134 and 135 the housing flanges 132 and 133 to grab.

The surfaces of the housing jacket and the housing socket facing each module end run at 90 degrees to their central axis.

The surfaces on the housing flanges 132 and 133 which are opposite to each other on the housing jacket run at an incline to the central axis.

The clamping devices 121 and 122 include the housing flanges located opposite each other at the housing ends. For this purpose, each clamping device is made up of ring sections that are put together around the flanges. The various ring sections are provided with a groove on the flange side so that the outer edges of the flanges fit together into the groove.
The lateral groove surfaces run under the same incline as the contact surfaces on the housing flanges.
If the ring sections are clamped, this leads to tension in the housing flanges, similar to clamps on a pipeline.

The clamping is possible because the ring sections are articulated to one another at one end. In the exemplary embodiment, cams are provided on the opposite ends of the sections for the articulated connection. In the exemplary embodiment, the connection is made by a double joint. For this purpose, a bearing pin is provided in each cam. Both bearing pins are connected to one another by brackets.

At the other end, the ring sections are pressed together by a clamping screw. The clamping screw consists of a screw part which is held pivotably in a cam on the lower ring section, and a screw nut embedded in a handle.
The clamping screw is brought into the clamping position by pivoting, so that the screw part reaches an opening of a slot provided on the upper ring section. Then the handle with the embedded screw nut is rotated.

12th shows various extruder modules which, after changing the connecting flanges, are suitable for the clamp connection according to the invention. With 50 is called a standard filling part. That Standard filling part 150 has an inlet opening above a screw in the casing. The feed material enters the filling part through the entry opening 150 and is compressed and conveyed in the discharge direction (from right to left in the view).

With 151 a filling part is referred to, which is designed in the manner of a planetary roller extruder. The filling part has 151 like the filler part 150 an entry opening in the housing jacket through which the feed material penetrates into the filling part. In contrast to the filling part 150 the input material hits the rotating planetary spindles and the input material has to get between the planetary spindles in order to be gripped by the planetary spindles and conveyed in the extrusion direction.

With 152 denotes a module to which a side arm extruder can be connected.
From the representation of the connection it can be seen that the side arm extruder is a twin screw extruder. The side arm extruder includes a forced feed of the feed material into the module 152 . With the twin screw extruder, both solids and liquid feed materials can be fed into the module 152 be worn.

With 153 is called a degassing module.

With 154 is another module with a connection for a side arm extruder.

With 155 and 156 are two common modules in planetary roller extruder design.

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

• DE 1577939 [0022]
• DE 102019000712 [0029]
• DE 19534813 C2 [0165]
• DE 202008017267 [0198]
• EP 2196529 [0198]
• DE 102008061171 [0198]
• EP 453859 [0202]
• DE 102019004945 [0208]

Claims (23)

Printing with melt to produce a molded part using an extruder and a print head with a nozzle, a) where the nozzle can be closed and b) the extruder has a backflow / leakage flow of the melt at least when the nozzle is closed, c) where one exiting the nozzle Melt band or a melt thread or a melt strand or a point-like melt application is generated characterized by the application to baked goods and / or confectionery goods, whereby a layer-by-layer melt application takes place. Procedure according to Claim 1 , characterized by the laying of layers of various types, with at least one layer of dough being provided. Procedure according to Claim 2 , characterized by the use of bottom layers and / or intermediate layers of dough and other layers of a different nature. Method according to one of the Claims 1 until 3 , characterized by a layered covering of other parts or layers. Method according to one of the Claims 1 until 4th , characterized in that the extruder and / or the print head are cleaned in the event of a longer interruption in operation. Method according to one of the Claims 1 until 5 , characterized in that the soiled extruder parts are replaced with clean extruder parts for cleaning and the soiled extruder parts are cleaned in a dishwasher. Method according to one of the Claims 1 until 6th , characterized by the use of an extruder constructed in modules / sections, the extruder modules / extruder sections having a maximum length of 500mm, preferably a maximum length of 400mm and even more preferably a maximum length of 300mm. Method according to one of the Claims 1 until 7th , characterized in that a modular / section-wise built extruder is used, the modules / sections of which have flanges at the housing ends which are held together by a clamping piece during extrusion operation which encompass the flanges at the edge. Method according to one of the Claims 1 until 8th , characterized by the use of a single screw extruder or twin screw extruder with a reduced conveying effect, preferably by using a planetary roller extruder with a reduced conveying effect. Method according to one of the Claims 1 until 9 , characterized in that a) that the nozzle is closed or opened by a displacement of the screw or central spindle and / or by a movement of the nozzle and / or by a slide or hollow jacket section and / or b) that a nozzle is used which is axially Direction of the worm or central spindle can be moved towards the tip of the worm or central spindle in order to close the nozzle completely or partially, and away from the tip of the worm or central spindle in order to open the nozzle completely or partially and / or c) that the nozzle can be moved in the axial direction of the extruder for opening and closing. and / or d) that the melt emerging from the nozzle is placed on a movable base / work table, with which all other movements for printing a workpiece take place. and / or e) that the nozzles are exchangeable at least at the outlet opening in order to give the emerging melt strand a different cross-section and / or f) that a screw or central spindle with a tapering tip is used, preferably with a conical tip or a spherical tip, which At least in the closed position of the nozzle, a nozzle with a tapering opening, preferably a conical opening, or a cylindrical opening, projects into the nozzle. Procedure according to Claim 10 , characterized by replacing the nozzles to change the emerging melt strand during the production of a molded part, preferably by using a linearly movable slide with at least one nozzle opening, preferably with several different nozzle openings, at the outlet opening of the melt feed line or by using a rotatable or pivotable cover with at least a nozzle opening, preferably with different nozzle openings, at the outlet opening of the melt supply line or by using a displaceable hollow jacket section with at least one nozzle opening, preferably with different nozzle openings, at the exit opening of the melt supply line. Procedure according to Claim 10 or 11 , characterized by the use of nozzles which can be pivoted at least on the outlet side, preferably by using a pivotable nozzle, the pivotability being given by a ball joint in the nozzle. Method according to one of the Claims 1 until 12th , characterized by the use of an extruder arranged vertically with the screw / spindle. Method according to one of the Claims 1 until 13th , characterized in that the melt consumption is measured and the feed material is tracked as a function of consumption, whereby one of the following measurements is preferably provided - measurement of the degree of filling in the extruder - measurement of the weight of the molded part being produced - measurement of the distance between the molded part being produced and the nozzle - measurement the fill level in the extruder Method according to one of the Claims 1 until 14th , characterized by the use of a planetary roller extruder with a reduced number of planetary spindles and / or a reduced number of teeth, preferably with a number of planetary spindles of at least 3 and an even distribution of the planetary spindles, the planetary spindles being redistributed evenly between the central spindle and the surrounding housing after each change in the number of planetary spindles will. Method according to one of the Claims 1 until 15th , characterized by one of the following features for reducing the number of teeth on the planetary spindles - teeth that have been completely or partially removed - teeth that are completely or partially interrupted Print according to one of the Claims 1 until 16 , characterized by a bypass for returning the melt quantities not removed for printing. Print according to one of the Claims 1 until 17th , characterized in that the molded parts are built up by laying the melt strands / threads / bands in layers / layers and the laying of a melt strand / thread / bands within a layer is interrupted if the melt strand / thread / bands are attached to an already laid melt strand / thread / Tapes or is continued at a point where no melt strand has yet been laid, and that preferably a line-by-line laying takes place within the layers / plies, with a reversal taking place when a molding edge is reached, even more preferably the laying of the melt strand / thread / Band at the transition to an adjacent line of a layer / layer takes place without interruption and a meandering course of the melt strand / thread / band results. Method according to one of the Claims 1 until 13th , characterized in that the melt strands / thread / band are laid at abutment points with other melt strands / thread / bands in the association and the melt strands / melt bands / thread preferably have an offset to adjacent melt strands / melt bands / thread of at least 1mm, even more preferably of at least 2mm, most preferably of at least 3mm and at most 4mm. Method according to one of the Claims 1 until 19th , characterized by the use of a planetary roller extruder, which is constructed in sections, in particular in modules, the housings of the sections / modules being lined with a socket, the housings being provided with housing flanges at the ends so that adjacent housing ends over the housing flanges with the centering of the Housing ends can be clamped together, with at least one common worm or a common central spindle extending through the clamped housing, a clamping part being provided for clamping two adjacent housing flanges and / or a ring construction being provided between the housing flanges, which at least by embracing the Housing bushing causes a centering. Procedure according to Claim 20 , characterized in that as a clamping part a clamping ring comprises the flanges to be braced against each other with a groove, the groove tapers towards the groove base and / or the contact surfaces on the housing flanges run at an incline, and the edge of the housing flanges touch the lateral groove surfaces and a range of motion is provided for the edge in the radial direction, so that the edge of the housing flanges can slide on the groove surfaces during the clamping process. Procedure according to Claim 20 or 21 , characterized in that clamping parts are used which consist of two clamping ring sections which are articulated to one another at one end and which can be clamped against one another at the other, or each section being clamped at each end to the associated end of the other section. Procedure according to Claim 20 or 21 , characterized by the use of a chain of clamping ring sections, the sections between the first and last section of the chain being connected to one another and to the first and last section of the chain in an articulated manner, in particular by a double joint, and the first and last section being connected to the free ends can be braced together, the bracing preferably taking place by means of a tensioning screw / anchor or by means of a toggle lever.

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