DE102018212496A1 - Process for the production of individually marked components - Google Patents

Abstract

In the method for producing individually labeled components, a respective component is produced by means of an additive manufacturing method and, using the same method, an element characterizing the component is arranged on a surface, arranged in the component material and / or embedded in the component material.

Description

The invention relates to a method for producing individually marked components. The components are to be manufactured using an additive manufacturing process.

In general, there is a requirement that almost all products should be labeled so that the respective products can be identified, differentiated and, if possible, assigned to a manufacturer. There are many known ways of doing this that have been used up to now. Counterfeit security also plays an important role in this.

For the labeling of products, however, it is usually necessary to place them either directly on the product or on a packaging using an additional method. For example, printing processes or very complex laser structuring processes are part of the prior art.

In the recent past, different processes for additive manufacturing, such as printing processes, selective laser sintering or melting, or stereolithographic techniques, have become established. With all additive processes, however, there is the disadvantage of the long production times required in comparison to conventional production processes, which leads to reduced productivity.

• o Positionierung auf Baufeld
• o Inhomogenitäten im Herstellungsprozess
• o Unterschiedliche Umgebungsbedingungen (gerade bei größeren Stückzahlen und mehreren unterschiedlichen Bauvorgängen)
• o (zumeist manuelle) Reinigung der Bauteile
• o Thermische Prozessierung und Positionierung im Ofen (Härteprozesse, Entbinderung, Sinterung)

• - Additive Verfahren werden aber nicht nur für die Herstellung einzelner Bauteile genutzt, sondern auch für größere Serien mit komplexen Geometrien
• - Integration eines Codes (z.B. QR- oder Barcode) durch Konstrukteur ist möglich, aber sehr aufwändig, da für jede Struktur ein geeigneter Platz (Fläche oder Volumen) ermittelt und für jedes Bauteil ein neuer Code/eine neue Datei erstellt werden muss.

Usually, all additively manufactured components are generated using computer programs and then transferred in a special data format to the additive manufacturing systems or associated software, in most cases as STL files. Components of a series are created with the same process / system and the same process parameters and should therefore be the same and indistinguishable. However, the properties of the components can vary due to many factors. The following factors can influence this:

• o Positioning on the construction site
• o Inhomogeneities in the manufacturing process
• o Different environmental conditions (especially with larger quantities and several different construction processes)
• o (mostly manual) cleaning of the components
• o Thermal processing and positioning in the furnace (hardening processes, debinding, sintering)

• - Additive processes are not only used for the production of individual components, but also for larger series with complex geometries
• - Integration of a code (e.g. QR or barcode) by the designer is possible, but very time-consuming, since a suitable space (area or volume) has to be determined for each structure and a new code / file has to be created for each component.

It is therefore an object of the invention to provide possibilities for individual identification of individual components, including the same components of a series, which require reduced effort.

According to the invention, this object is achieved with a method which has the features of claim 1. Advantageous refinements and developments of the invention can be realized with features designated in the subordinate claims.

With the method according to the invention, a respective component is produced by means of an additive manufacturing method and with the same method an element characterizing the component is arranged on a surface, arranged in the component material and / or embedded in the component material.

The characteristic element can advantageously be designed as a surface contour, in particular with elevations and / or depressions and / or inaccessible pore structure, with a color or physical density that differs from the component material or with at least one material that differs from the component material. Interference or holographic effects can be achieved with surface structures.

A material that differs from the component material can have a different thermal, different electrical conductivity, other magnetic, other optical properties, in particular a different optical refractive index, reflectivity, transparency, absorption behavior for electromagnetic radiation, luminescent properties or contains a radioactive isotope. A different material can also have a different speed of sound or a different sound insulation behavior than the actual component material.

This can be achieved by depositing a material that differs from the component material in a locally defined manner during the additive manufacturing process. This can be achieved particularly easily in printing processes or stereolithographic production.

A characteristic element can also be produced by the fact that material that differs from the component material contains a different consistency in individual components of a series, in particular different proportions of additives contained, which lead to individually different properties of the respective characteristic element, which can then be detected.

In the simplest case, characteristic elements can be detected optically by visual observation. However, suitable detectors can also be used, for example, to be able to detect different optical effects, different electrical conductivities, temperatures or the intensity of radiation emitted by a characteristic element. Non-contact detection and assignment can be achieved with detectors. For example, optical detectors, temperature sensors, magnetic flux detectors, X-ray detectors or antennas can be used for detection. Antennas can be used, for example, if a characteristic element has been designed as an electrical resonant circuit or with an electronic microprocessor that can perform RFID functions. In the case of a characteristic element with a microprocessor, electrical conductor tracks for electrical connections and / or an antenna can likewise be formed using the additive manufacturing method.

A characteristic element can be formed with numbers, letters, lines, dots, as a QR code, in the form of an electrical resonant circuit, with an electronic microprocessor or with electrical conductor tracks. A barcode known per se can be formed with lines or lines, for example.

In the method, depending on the number of a series of components to be manufactured additively, a computer program used for the production of components should be changed in such a way that on each individual component of the series an element that characterizes this component is formed. This computer program can also be used to determine an area on the surface and / or in the interior of the component in which the characteristic element is formed. The selection should be made with the aspect of maintaining the highest possible productivity during the production of the component and good and easy recognizability or detectability of a characteristic element formed on a component. In particular if characteristic elements have not been formed directly on the surface, the accessibility for detectability should be taken into account. A computer program can in particular be an STL file or another CAD program with which an additive manufacturing process can be controlled. This can also be done in various process steps as well as when creating the CAD data, e.g. after conversion to STL format (before or during the slicing process).

The use of luminescent substances for the formation of characteristic elements presupposes the possibility of stimulating luminescence. Therefore the possibility of a corresponding energy supply must be given. Since electromagnetic radiation is usually used, training on the surface of a component is appropriate in these cases.

Optical properties, and in particular the optical refractive index, transparency or reflectivity, can be set in many manufacturing processes by locally defined temperature differences which can be used, for example, in the curing of polymers.

Areas with different physical density, different sound speeds and / or different sound insulation behavior for characteristic elements can be designed, for example, in such a way that an area in which a characteristic element is formed with powdered component material in which thermally decomposable particles are contained or with powdered material the other Particle size as the material with which the component is produced without a characteristic element is manufactured additively and then a thermal treatment leading to sintering is carried out, in which the area in which the characteristic element has been formed has a different physical density than that Rest of the component. Thermally decomposable particles can in particular be polymers. Different densities in certain areas of a characteristic element or on different components can also be achieved with different proportions of thermally decomposable materials or particle sizes of thermally decomposable particles of powdery materials. In general, larger particle sizes lead to greater porosity and thus to a lower physical density than is the case with smaller particle sizes.

The individual identification of the individual components enables traceability across the entire process chain. Logging of each individual process step and assignment to the individual component can be achieved.

The characteristic elements that have been formed on a component can be visible from the outside. However, this is not absolutely necessary. Distinctive elements can also are deliberately made invisible from the outside. This is particularly the case when certain properties of the component material are selected locally differently than in the actual component material, which are not readily visible from the outside. Luminescent areas can only be detected after excitation. Suitable detectors are required for detection of changed electrical, magnetic, thermal properties. This also applies to possibly used isotopes.

In the invention, unique codes / identifications can be formed as identifying elements directly during the design or construction process, as a result of which the effort for individual product identification can be reduced. Integration in CAD / CAM data is possible.

• - Soll/muss dieser sichtbar sein?
• - Wie kann ein auslesen erreicht werden?
• - Welches additive Herstellungsverfahren wird für die Herstellung des Bauteiles genutzt bzw. kann genutzt werden und ist ein jeweiliges kennzeichnendes Element damit realisierbar?
• - Welche Position am Bauteil (Fläche oder Volumen) steht dafür zur Verfügung?

Different codes for distinctive elements are possible, in which the following points can be taken into account:

• - Should / must this be visible?
• - How can a readout be achieved?
• - Which additive manufacturing process is used or can be used for the manufacture of the component and can a respective characteristic element be realized with it?
• - What position on the component (area or volume) is available for this?

In principle, a characteristic element can be placed on / on the component, but also on a support or a base plate (if the latter is to be separated, the respective characteristic element must be able to be transferred before the separation. The position can also be provided by the designer directly for this or be specified.

The method can be used in such a way that a computer program, in particular a (STL) file, is changed accordingly, which is also necessary for the individual identification of each component during the production of a series of identical components which are successively produced in parallel or in parallel using an additive manufacturing method of the series can be achieved. A separate computer program (STL) file can also be created for each individual component.

The user can select a suitable method for additive manufacturing. Since the choice of the additive manufacturing process defines the component properties, the choice of the additive manufacturing process can be made according to the required component properties. The choice of the additive manufacturing process can determine the choice of labeling types and may even limit them.

The geometry should be compared with a database in which it can be determined whether it has already been produced using this method.

A suitable area / volume should be determined for a placement of the respective characteristic element.

The type of a characteristic element can be selected by the user based on suggestions by a software tool.

The user can enter the desired number of pieces of a series of components to be manufactured, so that each component of the series can be individually identified.

Then the creation of the coding for the individual characteristic elements and implementation in a (STL) file for the creation of new (STL) files for each individual component with an individual characteristic element can be achieved. The designation of the respective (STL) file should also contain the code of a identifying element for the respective component in order to enable clear assignment.

During or after the manufacture of the individual components, a protocol / database should be created automatically. Subsequent proof of the manufacture or the manufacturing conditions can thus be achieved.

The process sequence can also be created automatically and, if appropriate, the individual components can be arranged on a construction platform or a support.

A check can also be carried out to determine whether characteristic elements on a component influence the properties of the respective component. This can be achieved, for example, by means of simulation.

To improve or maintain the manufacturing quality, the (STL) file can be checked and repaired as a computer program.

With the invention, tracking or recognition of the individual characteristic elements that have been formed on / in the component can be achieved.

A check of characteristic elements for verifiability, uniqueness (forgery check), property right check can be carried out.

In principle, various options can be used for characteristic elements.

When creating geometric structures for distinctive elements, the location of the placement and / or the type of structure can be selected. Characteristic elements can be formed on the surface of a component so that they protrude from the surface (relief). However, they can also be formed as a depression in the surface (engraving). Characteristic elements can also be formed within the surface with at least one second material / material (surface contour remains the same).

Characteristic elements can be made externally accessible and visually visible or hidden inside and not visible from the outside. In this case, a geometric dimension of a structure can be selected one-dimensionally, for example with a sequence of points that have different distances from one another and / or number of points.

Two-dimensional characteristic elements can be defined geometric patterns, but they can also be formed on curved surfaces, for example QR code, bar code, point surface (Braille) or defined surface roughness. In principle, numbering is also possible.

With three-dimensionally designed characteristic elements, it is possible to create height differences within one- or two-dimensional structures.

Characteristic elements can be made with the component material, at least one material that differs from the component material, for example by adding permanent fillers (e.g. magnetic / non-magnetic, electrically conductive / electrically non-conductive, fluorescent, phosphorescent, doping), by adding pore formers and their removal in the debinding / Sintering process for the generation of porous structures (different density, light refraction, electrical / thermal conductivity, ...).

If a characteristic element is designed with an electronic microprocessor that can perform RFID functions, information relating to the respective component can be stored in a memory after manufacture. The production of such a characteristic element is possible, for example, using a multi-material printing process.

In the case of signal-based identifying elements, for example the ohmic resistance, the magnetic field strength / flux density / field lines, an oscillating circuit (near field communication structures), the interaction with electromagnetic radiation or sound waves can be detected. Optical and / or acoustic waves can also be specifically modified by characteristic elements in order to be able to detect differences. For this purpose, the creation of structures which generate predefined acoustic surface waves or which can be modified / measured to modify them can be used.

Characteristic elements can preferably be formed using a printing process. A characteristic element can e.g. be printed with the same material from which the component is made.

Characteristic elements formed in the component can be formed in the form of a buried structure from at least one material that differs from the component. A material that differs from the component material can be electrically or thermally conductive or specifically isolating; be magnetic or non-magnetic and thus differ from the component material. The position (start position) of a characteristic element embedded in the component material, which is not recognizable from the outside, can be indicated by optical markings (dots or other geometric structures) on the surface of the respective component, which can facilitate detection.

Powdery material can be used in the manufacture of components with a distinctive element. A different particle size can be selected for the formation of a characteristic element. Smaller particle sizes lead to a more fine-grained structure than is the case with larger particle sizes, which means that different physical or optical densities on the component and the respective characteristic element can be obtained.

In the event of damage to the respective component, the manufacturer can tell from the microstructure of the component whether the component was originally or from another manufacturer and decide whether the warranty can be effective - (copy protection / coding).

The invention will be explained in more detail below by way of example.

example 1

• - Vorlage der STL-Datei
• - Definition des Bereiches der Bauteile in dem eine kennzeichnendes Element ausgebildet werden soll
• - Auswahl der jeweiligen Geometrie oder Struktur für die Gravierung
• - Erstellung der zehn STL-Dateien mit durchnummerierter Gravur (z.B. Bauteilname und dahinter „-01“ bis „-10“)
• - Herstellung der keramischen Platten mittels additiven Fertigungsverfahren (z.B. Lithografie-basierte Keramikfertigung, LCM-Verfahren der Fa. Lithoz) aus Al₂O₃-Suspension
• - Reinigung und Entfernung von Stützstrukturen, Entbinderung und Sinterung

For a continuous individual marking of ten ceramic plates, each with the same geometry, in which the characteristic elements are to be formed on the surface in the form of an engraving, the procedure is as follows:

• - Submission of the STL file
• - Definition of the area of the components in which a characteristic element is to be formed
• - Selection of the respective geometry or structure for the engraving
• - Creation of the ten STL files with numbered engravings (e.g. component name followed by "-01" to "-10")
• - Production of the ceramic plates by means of additive manufacturing processes (eg lithography-based ceramic manufacturing, LCM process from the company Lithoz) from Al ₂ O ₃ suspension
• - Cleaning and removal of support structures, debinding and sintering

Example 2

• - Vorlage der STL-Datei
• - Definition des Bereiches für die Ausbildung eines kennzeichnenden Elements an den Bauteilen
• - Auswahl der jeweiligen Geometrie oder Struktur für die Relieferstellung
• - Erstellung der zehn STL-Dateien mit jeweils durchnummeriertem Relief (z.B. Barcode, der Bauteilname und -nummer codiert)
• - Herstellung der metallischen Platten mittels SLM- oder EBM-Verfahren aus Ti-6AI-4V-Pulver
• - Reinigung bzw. Entfernung der Stützstrukturen

For the formation of individual characteristic elements on ten metallic plates of the same geometry with a relief, you can proceed as follows:

• - Submission of the STL file
• - Definition of the area for the formation of a characteristic element on the components
• - Selection of the respective geometry or structure for the creation of the relief
• - Creation of the ten STL files, each with a numbered relief (e.g. barcode, the component name and number coded)
• - Production of the metallic plates using SLM or EBM processes from Ti-6AI-4V powder
• - Cleaning or removal of the support structures

Example 3

• - Vorlage der STL-Datei
• - Definition des Bereiches für die Ausbildung der kennzeichnenden Elemente an den zehn Zylindern (nur eine Linie parallel zur Zylinderachse in Oberfläche zulässig)
• - Auswahl der jeweiligen Geometrie oder Struktur für die Gravierung
• - Erstellung der zehn STL-Dateien mit durchnummerierter Gravur (z.B. Punktfolge, die Bauteilname und -nummer codiert, z.B. drei Punkte nebeneinander definieren den Startpunkt, danach mit definiertem Abstand entweder Punkt/Aussparung oder nicht → Binärcode)
• - Herstellung der polymeren Zylinder mittels Stereolithografie-Verfahren
• - Reinigung und Entfernung von Stützstrukturen

For the continuous marking of ten polymeric cylinders of the same geometry with engraving, you can proceed as follows:

• - Submission of the STL file
• - Definition of the area for the formation of the characteristic elements on the ten cylinders (only one line parallel to the cylinder axis in the surface allowed)
• - Selection of the respective geometry or structure for the engraving
• - Creation of the ten STL files with consecutively numbered engraving (e.g. point sequence, which encodes the component name and number, e.g. three points next to each other define the starting point, then with a defined distance either point / recess or not → binary code)
• - Production of the polymeric cylinders by means of stereolithography processes
• - Cleaning and removal of support structures

Example 4

• - Vorlage der STL-Datei
• - Definition des Bereiches für die Ausbildung der kennzeichnenden Elemente an den zehn Bauteilen
• - Auswahl der jeweiligen Geometrie oder Struktur für die Gravierung kennzeichnender Elemente
• - Erstellung der zehn STL-Dateien mit durchnummerierter Codierung (z.B. QR-Code, der Bauteilname und -nummer codiert)
• - Herstellung der keramischen Platten mittels CerAM T3DP-Verfahren (Eigenentwicklung des Fraunhofer IKTS, basiert auf der tropfenweisen Ablage aufgeschmolzener partikelgefüllter thermoplastischer Suspensionen, erlaubt die parallele Ablage verschiedener Werkstoffe) aus einer Glas-Suspension (für Bauteil) sowie einer Glas-Suspension mit fluoreszierenden Pigmenten (für Codierung)
• - Reinigung, Entbinderung und Sinterung

For a continuous marking of ten ceramic plates of the same geometry using a material that differs from the component material, you can proceed as follows:

• - Submission of the STL file
• - Definition of the area for the formation of the characteristic elements on the ten components
• - Selection of the respective geometry or structure for the engraving of characteristic elements
• - Creation of ten STL files with numbered coding (e.g. QR code, the component name and number coded)
• - Manufacture of the ceramic plates using the CerAM T3DP process (in-house development by Fraunhofer IKTS, based on the drop-by-drop deposition of melted, particle-filled thermoplastic suspensions, allows the parallel deposition of different materials) from a glass suspension (for component) and a glass suspension with fluorescent pigments (for coding)
• - cleaning, debinding and sintering

Claims (7)

Method for the production of individually marked components, in which a respective component is manufactured by means of an additive manufacturing method and with the same method an element characterizing the component is arranged on a surface, in the component material and / or embedded in the component material. Procedure according to Claim 1 , characterized in that the characteristic element is designed as a surface contour, in particular with elevations and / or depressions, with a color or physical density that differs from the component material or with at least one material that differs from the component material. Procedure according to Claim 2 , characterized in that at least one material different from the component material, which has a different thermal, electrical conductivity, other magnetic, optical properties, in particular a different optical refractive index, reflectivity, transparency, a different absorption behavior for electromagnetic radiation, a different sound velocity, a different sound insulation behavior , has a different physical density, has luminescent properties or contains a radioactive isotope, is used for the formation of a characteristic element. Method according to one of the preceding claims, characterized in that the characterizing element is formed with numbers, letters, lines, dots, as a QR code, in the form of an electrical resonant circuit, with an electronic microprocessor or with electrical conductor tracks. Method according to one of the preceding claims, characterized in that, depending on the number of a series of components to be produced additively, a computer program used for the production of components is changed such that an element that characterizes this component individually is formed on each individual component of the series. Method according to one of the preceding claims, characterized in that an area on the surface and / or in the interior of the component in which the characteristic element is formed is determined using a computer program used for the production of components. Method according to one of the preceding claims, characterized in that an area in which a characteristic element is formed with a thermally decomposable material, in particular a powdery material in the thermally decomposable particles are contained or with powdery material of a different particle size than the material , with which the component is produced without a characteristic element, is manufactured additively and then a thermal treatment leading to sintering is carried out, in which the area in which the characteristic element has been formed has a different physical density than the rest of the component.