Thermal marking of 3D printed objects

A method for marking a printed object is disclosed. For example, the method includes printing a three-dimensional (3D) object via a fused filament fabrication (FFF) printer, receiving a desired color marking to be marked on a surface of the 3D object, and controlling a point energy source to emit energy on a thermal treatment layer of the 3D object in accordance with the desired color marking.

The present disclosure relates generally to three-dimensional (3D) printed objects and relates more particularly to a method to thermally mark a 3D printed object.

BACKGROUND

Three-dimensional printers can be used to print 3D objects. The 3D printers can be used to print a variety of different types of objects using different types of materials. Different types of processes can be used for 3D printing, such as extrusion, fusion of powders, and UV-curing of inkjet printed materials, for example. 3D printing represents an alternative additive approach for printing a 3D object layer-by-layer, as opposed to a subtractive process where a block of material is machined/etched/chiseled to furnish the final object.

One type of additive 3D printing process may be fused deposition modeling (FDM), also known as fused filament fabrication (FFF). The FDM process may extrude a partially melted material that is dispensed in a layer onto a platform. The extruded material may be dispensed in a shape or pattern that is desired for each layer. The process may be repeated to print a three-dimensional object.

SUMMARY

According to aspects illustrated herein, there is provided a method, non-transitory computer readable medium, and an apparatus for marking a printed object. One disclosed feature of the embodiments is a method that prints a three-dimensional (3D) object via a fused filament fabrication (FFF) printer, receives a desired color marking to be marked on a surface of the 3D object, and controls a point energy source to emit energy on a thermal treatment layer of the 3D object in accordance with the desired color marking.

Another disclosed feature of the embodiments is a non-transitory computer-readable medium having stored thereon a plurality of instructions, the plurality of instructions including instructions which, when executed by a processor, cause the processor to perform operations that print a three-dimensional (3D) object via a fused filament fabrication (FFF) printer, receive a desired color marking to be marked on a surface of the 3D object, and control a point energy source to emit energy on a thermal treatment layer of the 3D object in accordance with the desired color marking.

Another disclosed feature of the embodiments is an apparatus comprising a processor and a computer readable medium storing a plurality of instructions which, when executed by the processor, cause the processor to perform operations that print a three-dimensional (3D) object via a fused filament fabrication (FFF) printer, receive a desired color marking to be marked on a surface of the 3D object, and control a point energy source to emit energy on a thermal treatment layer of the 3D object in accordance with the desired color marking.

DETAILED DESCRIPTION

The present disclosure broadly discloses a method and apparatus to thermally mark three-dimensional (3D) printed objects. As discussed above, various types of 3D printers can be used to print 3D objects. In some instances, it may be desirable to add writing, an image, or any other type of marking to a 3D object. Previous methods may not provide a sufficient resolution or may use methods that may not be compatible with fused deposition modeling (FDM) or fused filament fabrication (FFF) 3D printing methods.

For example, using different colored filaments and designing the 3D object with the different colored filaments can be complicated, expensive, and time consuming. In other examples, some methods may simply paint the desired color markings onto the 3D printed object. However, the paint may not be very durable and/or may have low resolution.

The present disclosure provides a method that can color text, images, or any other type of marking on a 3D object printed with FDM or FFF printers. The method may use a thermal treatment layer that can be thermally marked with an energy source. The energy source may be a point energy source that can provide high accuracy and resolution when applied to the thermal treatment layer to mark the printed object.

In one embodiment, the thermal treatment layer may be an additive that is part of the filament material that is extruded. However, the additive may react at a temperature that is higher than the melting/extrusion temperature of the filament material. As a result, the additive may not change color during the extrusion. Rather, the color of the additive may be selectively changed via a separate marking process with the point energy source.

The color change may be a chemical change to the physical properties of portions of the thermal treatment layer that are exposed to energy emitted by an energy source. The change may be caused by exposure to the energy. Thus, the color change may be more durable and more permanent than painting the marking onto the 3D object.

In one embodiment, the thermal treatment layer may be added as a coating after the 3D object is printed. Then, the point energy source may be applied to the coating at desired locations or patterns to create a marking. Thus, the present disclosure provides a process to provide high resolution coloring of a 3D printed object via thermal marking.

FIG.1illustrates an example system100of the present disclosure. In one embodiment, the system100may include a 3D printer102, a point energy source104, and a processor106. Although the 3D printer102, the point energy source104, and the processor106are illustrated as separate components, it should be noted that the 3D printer102, the point energy source104, and the processor106may be part of a single apparatus within a common housing.

In one embodiment, the processor106may be communicatively coupled to the 3D printer102and the point energy source104. The processor106may control operation of the 3D printer102and the point energy source104.

In one embodiment, the system100may include a computing device118. The computing device118may be a computer that can create a design for a 3D printed object110via computer aided drawing (CAD) programs. The computing device118may also create a desired marking120via the CAD programs.

In one embodiment, a desired marking120and an object design122may be generated by the computing device118and transmitted to the processor106. The object design122may be in a format that can be used by the 3D printer102(e.g., a .dxf file, .stl files, and the like). The desired marking120may include an image, text, a combination of an image and text, and the like, that can be marked on the object110that is printed.

The processor106may control the 3D printer102to print the object110in accordance with the object design122. In one embodiment, the 3D printer102may be a fused deposition modeling (FDM) or a fused filament fabrication (FFF) printer. It should be noted that the 3D printer102has been simplified for ease of explanation and may include additional components that are not shown (e.g., a heat source for fusing, a printhead to dispense a filament material108, a movable platform, and the like).

A FFF printer may extrude the filament material108layer-by-layer onto a platform to print the object110. The filament material108may be fed through a printhead that heats the filament material108to melt or nearly melt the filament material108. The printhead may then dispense the melted filament material108in accordance with the object design122.

After the object110is printed, the point energy source104may emit an energy source onto a location114on a surface112of the object110. The processor106may control the point energy source104to emit energy in accordance with the desired marking120.

In one embodiment, the point energy source104may be an energy source that can emit energy in a well-defined narrow beam of energy. For example, the point energy source104may be a laser. In one embodiment, the laser may be powered at a power level with a sufficient energy density to raise a temperature of the surface112of the object110enough make the desired marking120. The power level may be a function of a scanning speed. For example, at a slower scanning speed, lower energy levels can be used. At a higher scanning speed, a higher energy level can be used. In one embodiment, the laser may be a carbon dioxide laser that can emit energy between 5 Watts (W) to 50 W of energy.

Since the temperature generated by the amount of energy emitted by the point energy source104is higher than the extrusion temperature of the filament material108, the point energy source104may emit energy for short bursts or a short amount of time (e.g., a few seconds) to mark the surface112of the object110. The short bursts or short amount of time may prevent the point energy source104from deforming, damaging, or melting the surface112of the object110. In one embodiment, the point energy source104may make several passes over the location114on the surface112using the short bursts or a short amount of time to thermally mark the location114.

In one embodiment, the point energy source104may emit an energy source onto a location114on a surface112of the object110shortly after the filament material108is deposited. For example, after a layer of the filament material108is deposited, the filament material108may still be hot. Thus, a lower powered point energy source104may be used to color a location114of the surface112of the object110. In other words, some energy savings may be realized in using a lower powered energy source immediately after depositing the filament material108versus waiting until the entire object110is printed and cooled. In an example, the point energy source may be 1 W to 10 W of energy when used immediately after each layer of the filament material108is deposited.

In one embodiment, the point energy source104may emit different levels of energy. For example, the different levels of energy may correspond to different temperatures that can be used to thermally mark the object110. As discussed in further details below, the object110may be thermally marked with different colors. The different colors may be created by applying different energy levels to convert or activate different additives on the surface112of the object110.

In one embodiment, the object110may be rotated and/or moved to thermally mark different sides of the object110. The point energy source104may then thermally mark the sides of the object110to create images116on the object110.

In one embodiment, the surface112of the object110may include a thermal treatment layer. The thermal treatment layer may include additives that may react to a particular temperature to change colors or generate a desired color. In other words, the point energy source104may apply a localized amount of energy at the location114to color a portion of the thermal treatment layer via a physical change in the properties of the additive in the thermal treatment layer.

In one embodiment, the thermal treatment layer may include an additive that changes color at a particular temperature. The additive may include a leuco dye and an acid developer in a matrix. The leuco dye may include at least one of a crystal violet lactone, a triarylmethane, a sulfur dye, a vat dye, a fluoran dye, and the like. Examples of the acid developer may include diphenols, salicylic acid derivatives, octadecylphosphonic acid and the like. The matrix may further include metal salt activators and/or suppression agents. The metal salt activators may include a zinc salt of an aromatic carboxylic acid. The suppression agent may include 2-hydroxy-1-aminopropanol, butyl amine, and mixtures, thereof.

In another example, the additive may be an irreversible material. The irreversible material may include an irreversible inorganic thermochromic material. Examples of irreversible inorganic thermochromic materials may include copper (I) iodide, ammonium metava adate, manganese violet (Mn(NH4)2P2O7), and the like.

In one embodiment, different leuco dyes may be mixed together in the thermal treatment layer to create different colors. For example, different leuco dyes may change color at different temperatures. The point energy source104may emit energy at a first wattage to heat the thermal treatment layer to a first temperature to convert a first leuco dye into a first color. The point energy source104may then emit energy at a second wattage to heat the thermal treatment layer to a second temperature to convert a second leuco dye into a second color. The process may be repeated for any number of different lueco dyes that can change at different temperatures within the thermal treatment layer.

FIG.2illustrates block diagrams of different examples of how the thermal treatment layer can be included in the printed object110of the present disclosure. Example202illustrates a solid fill. For example, the thermal treatment layer may be mixed in with the filament material108. The combination of the thermal treatment layer and the filament material108may be formed into a roll to be fed to the 3D printer102and extruded. The additive in the thermal treatment layer may change color at a temperature that is higher than an extrusion temperature of the filament material108. As a result, the additive may not react to change color when exposed to the extrusion temperature that melts the filament material108during extrusion. The 3D printed object110may then contain the thermal treatment layer, which is mixed throughout the entire printed object110.

Example204illustrates a printed shell206. For example, the object110may be printed with the filament material108. Then, a second filament material with the thermal treatment layer can be extruded by the 3D printer102to form the printed shell206around the object110. In one embodiment, the 3D printer102may switch between the filament material108and the filament material mixed with the thermal treatment layer to print the outer shell206with the inner portion layer-by-layer.

Example208illustrates a spray coating. For example, the thermal treatment layer can be stored in a spray can210or dispenser. After the object110is printed by the 3D printer102, the thermal treatment layer can be spray coated onto the object110with the spray can210. The thermal treatment layer can be coated on desired portions of the object110or over the entire outer surface of the object110.

The thermal treatment layer may be allowed to dry on the object110. After the thermal treatment layer is dried, the point energy source104may thermally mark the thermal treatment layer to mark the object110with the images116.

Example212illustrates a dip coating. For example, a thermal treatment layer216can be stored in a container214. After the object110is printed by the 3D printer102, the object110may be dipped into the thermal treatment layer216. Desired portions of the object110may be dipped or the entire object110may be submerged in the thermal treatment layer216to coat the entire outer surface of the object110.

The thermal treatment layer216may be allowed to dry on the object110. After the thermal treatment layer216is dried, the point energy source104may thermally mark the thermal treatment layer216to mark the object110with the images116.

FIG.3illustrates an example of marking the printed object110with multiple colors of the present disclosure.FIG.3illustrates an example with two different colors. As noted above, different additives with different color change temperatures can be used to mark the object110with different colors.

In one embodiment, the object110may be marked with two different colors302and304. For example, the thermal treatment layer may include a first additive or leuco dye that changes color at a first temperature and a second additive or leuco dye that changes color at a second temperature. The first additive and the second additive can be mixed together in the thermal treatment layer or may be applied as separate thermal treatment layers to different portions of the object110.

The first additive may correspond to the color302and the second additive may correspond to the color304. In one embodiment, the point energy source104may emit energy at a first energy level onto the surface of the object110. The first energy level may heat the surface of the object110to a first temperature that causes the first additive to change to the color302.

After the desired portions of the surface of the object are marked with the first color302, the point energy source104may emit energy at a second energy level onto the surface of the object110. The second energy level may heat the surface of the object110to a second temperature that causes the second additive to change to the second color304. For example, any two temperatures above the extrusion temperature of the filament material108may be used (e.g., temperatures above 160 degrees Celsius (° C.)). For example, a first temperature of 250° C. can be used to change the first color302and a temperature of 400° C. can be used to change the second color304. Other example temperatures may also be used. For materials with higher melting temperatures, higher temperatures can be used for changing the colors302and304.

Although two different colors302and304are illustrated by example inFIG.3, it should be noted that any number of different colors can be generated. The number of different colors may correspond to the number different additives having different non-overlapping temperatures to activate a color change in the respective additives that are included in the thermal treatment layer.

FIG.4illustrates a flowchart of an example method400for marking a printed object of the present disclosure. In one embodiment, one or more blocks of the method400may be performed by the system100, or a computer/processor that controls operation of the system100as illustrated inFIG.5and discussed below.

At block402, the method400begins. At block404, the method400prints a three-dimensional (3D) object via a fused filament fabrication (FFF) printer. For example, the FFF printer or FDM printer may extrude a filament material layer-by-layer to print a 3D object. The object may be printed in accordance with an object design generated by a computing device in communication with the 3D printer.

At block406, the method400receives a desired color marking to be marked on a surface of the 3D object. The color marking may be a design generated by the computing device. The desired color marking may be text, an image, a graphic, or any combination thereof.

At block408, the method400controls a point energy source to emit energy on a thermal treatment layer of the 3D object in accordance with the desired color marking. In one embodiment, the thermal treatment layer may be mixed in with the filament material that is extruded. Thus, the filament material may be formed with the thermal treatment layer mixed throughout.

In one embodiment, the 3D object may be printed with an outer shell that includes the thermal treatment layer. For example, a filament material may be used to print the 3D object. Then the filament material mixed with the thermal treatment layer may be extruded to form the outer shell.

In one embodiment, the thermal treatment layer may be spray coated or dip coated onto the object. For example, the 3D object can be printed. After the 3D object is printed, the thermal treatment layer may be applied to the entire outer surface of the 3D object, or desired portions of the outer surface of the 3D object.

In one embodiment, the thermal treatment layer may include an additive that can change color when exposed to a particular temperature. The additive may include a leuco dye and an acid developer in a matrix. Examples of leuco dyes that can be used may include a crystal violet lactone, a triarylmethane, a sulfur dye, a vat dye, a fluoran dye, and the like.

In one embodiment, different additives can be mixed together to generate different colored markings on the 3D object. For example, different additives with different non-overlapping color change temperatures can be used to generate the different colored markings. The point energy source may apply a first energy level to heat the thermal treatment layer at a first temperature. One of the additives may react to the first temperature and change to a first color. The point energy source may apply a second energy level to heat the thermal treatment layer at a second temperature. Another one of the additives may react to the second temperature and change to a second color.

Thus, the method400may provide an efficient non-contact method for thermally marking the 3D printed object to create color markings on the surface of the 3D printed object. Thus, using direct coloration with inks or paint or adding materials can be avoided with the embodiments of the present disclosure. At block410, the method400ends.

FIG.5depicts a high-level block diagram of a computer that is dedicated to perform the functions described herein. As depicted inFIG.5, the computer500comprises one or more hardware processor elements502(e.g., a central processing unit (CPU), a microprocessor, or a multi-core processor), a memory504, e.g., random access memory (RAM) and/or read only memory (ROM), a module505for marking a printed object, and various input/output devices506(e.g., storage devices, including but not limited to, a tape drive, a floppy drive, a hard disk drive or a compact disk drive, a receiver, a transmitter, a speaker, a display, a speech synthesizer, an output port, an input port and a user input device (such as a keyboard, a keypad, a mouse, a microphone and the like)). Although only one processor element is shown, it should be noted that the computer may employ a plurality of processor elements.