In three-dimensional (3D) printing, an additive printing process is often used to make three-dimensional solid parts from a digital model. 3D printing can be used in rapid product prototyping, mold generation, mold master generation, and short run manufacturing.
Where ever possible the same reference numbers are used throughout the drawing(s) and accompanying written description to refer to the same or like parts. The figures are not necessarily to scale and certain features and certain views of the figures can be shown exaggerated in scale or in schematic for clarity and/or conciseness. Additionally, several examples have been described throughout this specification. Any features from any example can be included with, a replacement for, or otherwise combined with other features from other examples.
Certain examples are shown in the identified figures and disclosed in detail herein. Although the following discloses example methods and apparatus, it should be noted that such methods and apparatus are merely illustrative and should not be considered as limiting the scope of this disclosure.
As used herein, directional terms, such as “upper,” “lower,” “top,” “bottom,” “front,” “back,” “leading,” “trailing,” “left,” “right,” etc. are used with reference to the orientation of the figures being described. Because components of various examples disclosed herein can be positioned in a number of different orientations, the directional terminology is used for illustrative purposes and is not intended to be limiting.
Additive manufacturing processes can be used to manufacture parts having complex geometries. However, parts manufactured via additive printing processes are often limited to a small section of materials (e.g., 3D printable materials). For example, a small portion of polymer materials in the manufacturing industry can be used as 3D printing material(s). Thus, material availability has been a significant limitation for 3D printing processes compared to other manufacturing processes. Additionally, additive manufacturing processes can be expensive and/or can be time consuming process. In some instances, 3D printed parts can have relatively weak strength (e.g., mechanical strength, stress or strain characteristic(s)) compared to, for example, machined parts or molded parts. Other manufacturing processes employing molds are compatible with many different types of materials (e.g., thermoplastic and thermosetting polymer materials, etc.). However, such manufacturing processes employing molds are limited to the production of simple geometries because complex parts cannot be separated from the molds.
Examples disclosed herein provide methods for manufacturing molds having complex geometries via additive manufacturing processes (e.g., 3D printed molds). For example, 3D printing techniques or processes are considered additive processes because the 3D printing processes involve the application of successive layers of material. Example 3D printing processes involve curing or fusing of a building material, which can be accomplished using heat-assisted extrusion, melting, sintering, digital light projection technology, etc. For example, 3D printed objects can be printed using, for example, a multi-jet fusion (MJF) process. MJF is a powder-based technology. A powder bed is heated uniformly at the outset. A fusing agent is jetted where particles need to be selectively molten, and a detailing agent is jetted around the contours to improve part resolution and/or improve temperature distribution (e.g., across a build material) to control a porosity of a 3D printed mold. While lamps pass over a surface of the powder bed, the jetted material captures the heat and helps distribute the heat evenly.
In some examples disclosed herein, 3D printed molds can be manufactured via MJF technology. The 3D printed molds are then employed in other manufacturing processes such as, for example, injection molding, casting etc., to manufacture parts using non-3D printable materials. After formation of the 3D printed mold, a moldable material can be provided in a cavity of the 3D printed mold. As used herein, a “moldable material” is any material such as, for example, a liquid, a powder, clay, etc., that becomes liquid or malleable when heated (e.g., to a temperature of 150 degrees Fahrenheit (° F.)) and solidifies when cooled (e.g., to room temperature). For example, the moldable material can be, for example, a liquid or a powder, a polymer, a molten material, a liquid polymer, a polymer mixed with metal or ceramics, a low-temperature metal, thermosetting material(s) such as resigns that can be cured (e.g., UV cured) to solidify after molding, and/or any other suitable material(s). The moldable material can then be treated (e.g., cooled, cured, etc.) for solidification. After solidification of the molded material, the mold can be separated (e.g., destroyed and removed) from the molded part. Thus, the example 3D printed molds disclosed herein can be single use molds that can be broken down and removed from a molded part after formation of the molded part.
In 3D printing processes, full solidification of materials has always been desired for highest mechanical strength possible. For example, in thermal powder bed-based 3D printing processes, such as MJF for plastic materials, process parameters are optimized to avoid under-fused powder to form fully dense parts (e.g., parts having 0% to 1% porosity). As used herein, “porosity” means a measure of void (i.e. “empty”) spaces in a material. In some examples, porosity is determined as a fraction of a volume of voids over a total volume, or as a ratio of a volume of interstices of a material to a volume of its mass. A degree of fusion in powder bed-based 3D printing processes affects resulting material properties such as, for example, Young's modulus, ultimate strain and stress, etc. Therefore, printing a 3D part with an under-fused polymer powder can present mechanical strength properties that differ from (e.g., are inferior to) mechanical strength properties of a fully-fused polymer powder.
To facilitate separation of a mold from a molded part, example 3D printed molds disclosed herein can be formed with under-fused polymer powder during the 3D printing process. For example, to form a 3D printed mold having under-fused layers, a level of fusion of each layer of the 3D printed mold is varied during a 3D printing process. As used herein, a level of fusion refers to controlling an amount of fusing agent and/or an amount of heat to be received by a build material to affect or control an amount of melt of particles to be selectively molten. As a result, example systems and methods disclosed herein control a porosity of a 3D printed mold when forming the 3D printed mold using additive manufacturing process(es). For example, forming 3D printed molds disclosed herein with under-fused powder decreases a mechanical strength of the 3D printed mold compared to a mechanical strength of a 3D printed mold formed from a fully-fused powder. Therefore, the mold can be formed with a smaller mechanical strength characteristics to facilitate removal of the 3D printed mold from a molded part. As a result, the 3D printed mold has sufficient strength to maintain its shape during a molding process but can be broken down (e.g., destroyed) after formation of the molded part using, for example a tool (e.g., a hammer).
To form a 3D printed mold disclosed herein with a varying or controlled-degree of porosity (e.g., a porosity between 20 percent and 30 percent) and/or a level a fusion of each layer, the examples disclosed herein vary a fusing agent (e.g., MJF process), a detailing agent (e.g., a cooling agent), an energy level (e.g. SLS process), a binder agent (e.g., 3D binder jetting), etc. during the printing process.
For example, to control fusion levels and/or vary (e.g., increase) a porosity during an MJF 3D printing process, examples disclosed herein employ (1) a contone level-controlled approach or (2) a heat transfer-controlled approach. In the contone level-controlled approach, a volume (e.g., an amount) of fusing agents can be applied to each layer of the 3D printed part (e.g., under-fused layers) at lower contone levels to vary (e.g. increase) a porosity of each 3D printed layer. The desired fusing degree of the under-fused layer can be achieved by the corresponding contone level.
To vary porosity and/or fusing level characteristics during a selective laser sintering (SLS) process, examples disclosed vary an energy provided to a build material during the SLS process. For example, an SLS process employs a laser that provides energy sufficient to cause particles of a build material to fuse together and form a solid structure. Thus, to vary the porosity, a lower amount of energy (e.g., a first amount of heat) can be provided to a layer of a 3D printed mold that is less than an energy level needed to fully-fuse the layer.
Example disclosed herein can be employed with 3D binder jetting processes. For example, 3D binder jetting is an additive manufacturing process that forms 3D printed parts or molds additively with a binding agent. In some examples, the 3D binder jetting process uses a liquid binding agent deposited on a metal powder material, layer by layer, according to a 3D model. In some such examples, a porosity of a 3D printed mold can be varied by adjusting or varying an amount of at least one of the binder agent or an energy applied to a build material and the binder agent.
In some examples, the example methods disclosed herein can employ a detailing agent (e.g., a cooling agent) to vary a porosity of a 3D printed mold. The detailing agent maintains a temperature of a build material cooler than a temperature of a build material that does not have the detailing agent to reduce or prevent the effects of thermal bleed between the build layer and, thereby, control (e.g., increase) a porosity of the build layer. Thus, although the example disclosed herein are discussed in connection with MJF process, the examples can be implemented with SLS processes, 3D binder jetting processes, and/or any other additive manufacturing process(es).
Turning more specifically to the illustrated examples,
The workstation 100 includes an example controller 104 and an example printer 106 (e.g., a 3D printer). The controller 104 may be a computing device, a semiconductor-based microprocessor, a central processing unit (CPU), an application specific integrated circuit (ASIC), and/or other hardware processing device. The controller 104 can be communicatively coupled to an example computing device 110 (e.g., a desktop, a server, etc.) via an example network 108 (e.g., a wireless network, a wired network, etc.). For example, the computing device 110 may be a computer that sends instructions to the controller 104 to print or produce the 3D printed mold 102. While an example network topology is shown in
The printer 106 of the illustrated example includes an example build material dispenser 112, an example support bed 114, an example fusing agent dispenser 116, an example detailing agent dispenser 118, and an example energy source 120. The build material dispenser 112, the fusing agent dispenser 116, and/or the detailing agent dispenser 118 can be piezo dispensers, thermal inject cartridges or print heads, and/or any other dispenser or inkjet cartridge(s) or print heads that eject material(s) during a printing process. The energy source 120 can be, for example, a laser, infrared light, ultraviolet light, a heat lamp, a heating element, and/or can be any other source that produces heat.
In operation, the workstation 100 of the illustrated example can: (1) receive a digital image that includes an identifier corresponding to a target porosity of the 3D printed mold 102, or (2) modify a digital file with a target porosity received via an input command (e.g., a user interface). Based on the digital file and the target porosity, the controller 104 determines an amount of build material, fusing agent and/or energy needed to form the 3D printed mold 102 in accordance with a pattern associated 3D printed mold 102 and/or a target porosity of the 3D printed mold 102. For example, the controller 104 causes the build material dispenser 112 to dispense a volume of building material, the fusing agent dispenser 116 to dispense a volume of the fusing agent, the detailing agent dispenser 118 to dispense a volume of the detailing agent and/or the energy source 120 to generate energy in accordance with the targeted porosity. In some examples, the workstation 100 receives information (e.g., a file) including an amount of fusing agent, an amount of the detailing agent and/or an amount of the energy level to be applied to achieve a target porosity and the controller 104 controls the dispensing of the fusing agent, the detailing agent and/or the amount of energy to be applied based on the received information. For example, in some examples the workstation 100 receives the target porosity and/or instructions from the computing device 110. For example, the computing device 110 can provide information to the workstation 100 regarding a volume of building material to be dispensed by the build material dispenser 112, a volume of the fusing agent to be dispensed by the fusing agent dispenser 116, a volume of the detailing agent to be dispensed by the detailing agent dispenser 118, and/or an amount of energy to be provided by the energy source 120 to generate the 3D printed part 102 in accordance with the targeted porosity.
The printer 106 of the illustrated example produces the 3D printed mold 102 by building a plurality of layers 122 (e.g., vertical layers). For example, a first layer 122a of the 3D printed mold 102 aligns with a second layer 122b. The first and second layers 122a of the illustrated example are formed with a porosity between approximately 2% and 45% (e.g., between 20% and 30%) based on the target porosity determined and/or received by the controller 104. In some examples, the second layer 122b is formed with a porosity that is similar or identical to a porosity of the first layer 122a. For example, in some instances, the porosities of the first and second layers 122a, 122b vary due to manufacturing tolerances when a target porosity of the first layer 122a input to the controller 104 is the identical to a target porosity of the second layer 122b input to the controller 104. For example, the first porosity of the first layer 122a can be within a percentage (e.g., between approximately 1 percent and 5 percent) of a porosity of the second layer 122b.
As a result of the controlling the porosities by forming the layers 122 of the 3D printed mold 102 as under-fused (e.g. partially-fused) layers, the 3D printed mold 102 has mechanical strength characteristic(s) (e.g., ultimate strain and stress, impact resistance, etc.) that is different than (e.g., less than) mechanical strength characteristic(s) (e.g., ultimate strain and stress, impact resistance) of a fully-fused 3D printed mold. For example, when the 3D printed mold 102 is composed of nylon 12, the 3D printed mold 102 (e.g., a partially-fused 3D printed mold) can have an ultimate stress characteristic of between approximately 5 megapascal (MPa) and 20 MPa (e.g., 10 MPa). In contrast, a fully-fused 3D printed mold can have an ultimate stress characteristic of between approximately 80 MPa and 120 MPa (e.g., 100 MPa). To this end, the 3D printed mold 102 enables or facilities separation of the 3D printed mold 102 into multiple segments or structures after formation of the molded part 126. Thus, a force imparted to the 3D printed mold 102 causes the 3D printed mold 102 to break or separate and removed from the molded part 126.
To control a level of fusion of the layers 122 of the 3D printed mold 102, the examples disclosed herein control a temperature or heat absorption of a build material during printing of the 3D printed mold 102. For example, by controlling a temperature or heat absorption of the build material, the porosity can be controlled (e.g., substantially homogeneously) across an entire surface area or volume of the first layer 122a, the second layer 122b, etc. To control the temperature of a build material of the layers 122 during printing process and control (e.g., increase) the porosity of the 3D printed mold 102, examples disclosed herein include controlling at least one of: (1) a contone level of a fusing agent; or (2) a heat transfer during the printing process.
After formation of the 3D printed mold 102, the 3D printed mold 102 can be used to form a molded part 126 via other molding (e.g., casting) manufacturing processes. After the molded part 126 solidifies in the 3D printed mold 102, the 3D printed mold 102 is removed from the molded part 126 by separating the 3D printed mold 102 into multiple segments or pieces. The pieces of the 3D printed mold 102 are removed from the molded part 126.
The examples disclosed herein are not limited to MJF process. For example, the workstation 100 can be configured to implement any other suitable additive manufacturing processes. In some examples, the examples disclosed herein can employ a detailing agent process, a selective laser sintering (SLS), or a 3D binder jetting process to control a porosity of the 3D printed mold 102.
To implement a detailing agent process, the workstation 100 of FIG.1 can be configured to dispense a detailing agent (e.g., water, a cooling agent, etc.) to control a temperature of the layers 122. For example, the controller 104 can cause the detailing agent dispenser 118 to dispense a detailing agent (e.g., a liquid, water, etc.) on a build material on the layers 122. During a fusing process of the 3D printed mold 102 that occurs during a printing process, the detailing agent maintains a temperature of the building material cooler than the fusing agent disposed on the build material to enable a lesser amount of heat or energy absorption and cause the build material (e.g., the first layer 122a) to be under-fused.
Alternatively, in some examples, the workstation 100 can be configured to implement a selective laser sintering (SLS) apparatus or process. In some such examples, the energy source 120 can be a laser that applies energy to a build material provided by the build material dispenser 112. To vary a porosity of a 3D printed mold, the energy source 120 varies an amount of energy provided to (e.g., a layer of) the 3D printed mold. In some such examples, the workstation 100 does not include the fusing agent dispenser 116 and the detailing agent dispenser 118.
In some examples, the workstation 100 can be configured to implement a 3D binder jetting process. For example, the printer 106 can include a binder agent dispenser instead of the fusing agent dispenser 116 and the detailing agent dispenser 118. To vary a porosity of a 3D printed mold, the printer 106 can vary at least one of a binder agent provided to a build material or an amount of energy provided to the binder agent and the build material.
The example 3D printed mold 102 does not include any inserts or structures (e.g., metal inserts) to define or enable the breakaway feature. The breakaway feature is enabled by the porosity or fusion level of the 3D printed mold 102 that is controlled during printing (e.g., an MJF printing process, an SLS printing process, a 3D binder jetting process, etc.) of the 3D printed mold 102.
While an example manner of implementing the workstation 100 is illustrated in
To produce the 3D printed mold 102, the controller 104 causes the build material dispenser 112 to dispense a build material 202 on the support bed 114 (e.g., a powder bed-based 3D printing processes). The build material 202 is a powder based material (e.g., nylon powder). In some examples, the build material dispenser 112 dispenses or deposits the build material uniformly across (e.g., an entire) working area of the support bed 114. To facilitate fusion (e.g., solidification) of the build material 202, the fusing agent dispenser 116 dispenses a fusing agent 204 (e.g., an agent) on the build material 202. Specifically, the fusing agent 204 is jetted on the build material 202 at locations or regions where particles of the build material 202 are to be selectively molten or fused together. To generate a pattern corresponding to the 3D printed mold 102, the controller 104 of the illustrated example controls dispensing the fusing agent 204 at specific locations relative to the build material 202 via the fusing agent dispenser 116. In some examples, a detailing agent 206 is jetted (e.g., via the detailing agent dispenser 118) around the contours of fused portions of the 3D printed mold 102 to improve part resolution. In some examples, the detailing agent 206 is provided at peripheral or terminating edge 208 of the 3D printed mold 102. In contrast to the fusing agent 204, the detailing agent 206 reduces or prevents fusion or solidification of the build material 202. In some examples, the detailing agent 206 is provided on the build material 202 and/or the fusing agent 204 to improve heat transfer and/or heat distribution during a fusing process.
To solidify or fuse the build material 202 to a structural component 210 (e.g., a solid structure), the controller 104 causes the energy source 120 (e.g., infrared light) to heat (e.g., pass over) the build material 202. As the energy source provides energy (e.g., heat) to the build material 202, the fusing agent 204 absorbs the energy (e.g., heat) and distributes the energy (e.g., heat) evenly to portions of the build material 202 that includes the fusing agent 204 and/or the detailing agent 206. Thus, the fusing agent 204 enhances fusion or solidification of the build material 202. The detailing agent 206, on the contrary, reflects heat from the energy source 120 and does not allow the build material 202 to solidify or fuse, thereby facilitating removal of the 3D printed mold 102 from the support bed 114. In some examples, as noted above, the detailing agent 206 can be provided on the fusing agent 204 to improve energy distribution across the fusing agent 204 and/or the build material 202.
After the first layer 122a of the 3D printed mold 102 is formed, the second layer 122b of the 3D printed mold 102 is formed. For example, after formation of the first layer 122a, the controller 104 causes the build material dispenser 112 to deposit the build material 202 on the first layer 122a and causes the fusing agent dispenser 116 to dispense the fusing agent 204 on the build material 202 of the second layer 122b that is to molten or solidify. The energy source 120 applies energy to the build material 202, and the build material 202 solidifies at locations that includes the fusing agent 204 to form the second layer 122b of the 3D printed mold 102. The process repeats to form the plurality of layers 122 until formation of the 3D printed mold 102 is completed.
To define a porosity of the 3D printed mold 102, the controller 104 varies or controls at least one of an amount of the fusing agent 204, the detailing agent 206 or energy level, and/or a combination thereof, during formation of the 3D printed mold 102. Thus, to provide the first layer 122a, the second layer 122b, etc. (e.g., and, thus, the plurality of layers 122 and 3D printed mold 102) with a porosity based on the target porosity, at least one of the fusing agent 204, the detailing agent 206 and/or the energy level is varied during manufacturing (e.g., printing) of the 3D printed mold 102.
Additionally, in some examples, the first layer 122a can have a first region 304 that has a porosity that is less than a porosity of a second region 306 by an amount greater than the manufacturing tolerance (e.g., greater than 10 percent). For example, the second region 306 can have a porosity between 1 percent and 10 percent, and the first region 304 can a porosity between 20 percent and 30 percent. In some such examples, the second region 306 can represent features of the 3D printed mold 102 that may require increased mechanical strength characteristic(s). For example, a wall thickness defined by the second region 306 may be smaller than a wall thickness defined by the first region 304 and, thus, may need to be formed with increased strength.
The contone-level control approach 400 is also applicable during a 3D binder jetting process. For example, a contone-level of the binder agent can be controlled to vary a porosity of a 3D printed mold formed via a 3D binder jetting process.
The molded part 900 of the illustrated example is a cylinder. The molded part 900 includes a cylindrical body 902 having an opening 904. The cylindrical body 902 is formed by the cavity 706 of the 3D printed mold 700 and the opening 904 is defined by the center post 704. For example, a distance between the inner surface 710 of the outer walls 702 and the outer surface 712 of the center post 704 defines a thickness 906 of the molded part 900 and an outer diameter of the center post 704 defines a diameter 908 of the opening 904. A length between the base 714 and the upper wall 708 defines a length 910 of the molded part 900.
As mentioned herein, the example processes of
“Including” and “comprising” (and all forms and tenses thereof) are used herein to be open ended terms. Thus, whenever a claim employs any form of “include” or “comprise” (e.g., comprises, includes, comprising, including, having, etc.) as a preamble or within a claim recitation of any kind, it is to be understood that additional elements, terms, etc. may be present without falling outside the scope of the corresponding claim or recitation. As used herein, when the phrase “at least” is used as the transition term in, for example, a preamble of a claim, it is open-ended in the same manner as the term “comprising” and “including” are open ended. The term “and/or” when used, for example, in a form such as A, B, and/or C refers to any combination or subset of A, B, C such as (1) A alone, (2) B alone, (3) C alone, (4) A with B, (5) A with C, (6) B with C, and (7) A with B and with C.
The example method 1300 of
Referring to
The controller 104 determines a target porosity for the 3D printed mold (block 1404). For example, the controller 104 can obtain the target porosity from the digital file of the 3D printed mold 102. In some examples, the controller 104 receives or obtains the target porosity via an input (e.g., a user input at the printer 106 and/or via the example network 108).
The controller 104 of the illustrated example causes the build material dispenser 112 to distribute the build material 202 on the support bed 114 to define a first layer 122a of the 3D printed mold 102 (block 1406).
The controller 104 of the illustrated example causes the fusing agent dispenser 116 to dispense a first amount 404 of the fusing agent 204 on the build material 202 to define a porosity of the first layer 122a of the 3D printed mold 102 in accordance with the target porosity (block 1408). In some examples, the controller 104 can cause the fusing agent dispenser 116 to dispense a second amount of the fusing agent 204 on a second portion of the first layer 122a of the build material 202 to define a second region 306 of the first layer 122a of the 3D printed mold 102, where the first amount 404 is different than (e.g., less than) the second amount 504.
To controller 104 of the illustrated example causes the detailing agent dispenser 118 to dispense a second amount of the detailing agent 206 on at least one of the build material 202 or the fusing agent 204 (block 1410).
To solidify the first layer 122a of the 3D printed mold 102, the controller 104 causes the energy source 120 to apply energy (e.g., heat) to the first layer 122a of the build material 202, the fusing agent 204 and the detailing agent 206 (block 1412). The energy provided by the energy source 120 is to cause the build material 202 to molten and solidify into the first layer 122a of the 3D printed mold 102 after cooling.
To define a porosity of the first layer 122a (e.g., the 3D printed mold 102), the controller 104 of the illustrated example varies the amount of at least one of the fusing agent 204, the detailing agent 206, or the energy (block 1414). For example, the controller 104 determines (e.g., calculates) the amount and/or location of the fusing agent 204, the detailing agent 206 and/or the build material 202 based on a pattern of the 3D printed mold 102 (e.g., from the digital file) and the determined target porosity, and operates the build material dispenser 112 and/or the fusing agent dispenser 116 to dispense such determined amounts. In some examples, the controller 104 can control the energy source 120 to generate an amount of heat needed to solidify the first layer 122a (e.g., the layers 122) with a porosity associated with the target porosity. For example, the controller 104 can vary amounts of the fusing agent 204, the detailing agent 206, and/or the energy level to enable the first layer 122a to achieve a porosity of between 20 percent and 30 percent based on the target porosity value of approximately 25%. The process is repeated until all layers 122 defining the 3D printed mold 102 are complete.
The processor platform 1500 of the illustrated example includes a processor 1512. The processor 1512 of the illustrated example is hardware. For example, the processor 1512 can be implemented by integrated circuit(s), logic circuit(s), microprocessor(s), GPU(s), DSP(s), or controller(s) from any desired family or manufacturer. The hardware processor may be a semiconductor based (e.g., silicon based) device. In this example, the processor implements aspect(s) of the example controller 104, the example printer 106, the example build material dispenser 112, the example fusing agent dispenser 116, the detailing agent dispenser 118, the example energy source 120 and/or, more generally, the example workstation 100 of
The processor 1512 of the illustrated example includes a local memory 1513 (e.g., a cache). The processor 1512 of the illustrated example is in communication with a main memory including a volatile memory 1514 and a non-volatile memory 1516 via a bus 1518. The volatile memory 1514 may be implemented by Synchronous Dynamic Random Access Memory (SDRAM), Dynamic Random Access Memory (DRAM), RAMBUS® Dynamic Random Access Memory (RDRAM®) and/or any other type of random access memory device. The non-volatile memory 1516 may be implemented by flash memory and/or any other desired type of memory device. Access to the main memory 1514, 1516 is controlled by a memory controller.
The processor platform 1500 of the illustrated example also includes an interface circuit 1520. The interface circuit 1520 may be implemented by any type of interface standard, such as an Ethernet interface, a universal serial bus (USB), a Bluetooth® interface, a near field communication (NFC) interface, and/or a PCI express interface.
In the illustrated example, input device(s) 1522 are connected to the interface circuit 1520. The input device(s) 1522 perm it(s) a user to enter data and/or commands into the processor 1512. The input device(s) can be implemented by, for example, an audio sensor, a microphone, a camera (still or video), a keyboard, a button, a mouse, a touchscreen, a track-pad, a trackball, isopoint, and/or a voice recognition system. For example, the input device(s) 1522 can receive a target porosity value.
Output device(s) 1524 are also connected to the interface circuit 1520 of the illustrated example. The output devices 1524 can be implemented, for example, by display devices (e.g., a light emitting diode (LED), an organic light emitting diode (OLED), a liquid crystal display (LCD), a cathode ray tube display (CRT), an in-place switching (IPS) display, a touchscreen, etc.), a tactile output device, a printer, and/or speaker. The interface circuit 1520 of the illustrated example includes a graphics driver card, a graphics driver chip and/or a graphics driver processor.
The interface circuit 1520 of the illustrated example also includes a communication device such as a transmitter, a receiver, a transceiver, a modem, a residential gateway, a wireless access point, and/or a network interface to facilitate exchange of data with external machines (e.g., computing devices of any kind) via a network 1526. The communication can be via, for example, an Ethernet connection, a digital subscriber line (DSL) connection, a telephone line connection, a coaxial cable system, a satellite system, a line-of-site wireless system, a cellular telephone system, etc.
The processor platform 1500 of the illustrated example also includes mass storage device(s) 1528 for storing software (e.g., machine readable instructions) and/or data. Examples of such mass storage devices 1528 include floppy disk drives, hard drive disks, compact disk drives, Blu-ray disk drives, redundant array of independent disks (RAID) systems, and digital versatile disk (DVD) drives.
The machine executable instructions 1532 of
The example methods, apparatus, systems, and articles of manufacture disclosed herein provide breakaway features for easy mold breakdown and removal. The breakaway features are formed by portions of the mold that are relatively weakly connected or coupled to stronger portions of the mold. A strength (e.g., or weakness) of the breakaway features can be varied during printing of the 3D printed mold. As a result, the mold has strength to withstand handling and maintain its shape during a molding process. Meanwhile, the mold can be broken down easily after a molded part is formed using the mold. The example 3D printed molds disclosed herein can be formed with higher geometric accuracy or precision than forming a mold using other manufacturing processes (e.g., machining).
At least some of the aforementioned examples include at least one feature and/or benefit including, but not limited to, the following:
In some examples, a method for forming a mold having a cavity by creating a plurality of layers using an additive manufacturing process includes: providing a build material; and controlling a fusion level of the build material separately for different layers of the plurality of layers to separately form the layers with a porosity corresponding to a target porosity.
In some examples, the controlling of the fusion level includes controlling a contone level of at least one of a fusing agent or a detailing agent.
In some examples, the controlling of the fusion level includes controlling a heat transfer.
In some examples, the controlling of the fusion level includes varying at least one of a binder agent or an energy level provided to the build material.
In some examples, the controlling of the fusion level includes controlling an energy level provided to the build material.
In some examples, the controlling of the fusion level includes providing a detailing agent to the build material.
In some examples, controlling the fusion level enables a porosity of the layer to between approximately 2 percent and 45 percent.
In some examples, after formation of the mold, the method further includes: providing a moldable material in the cavity of the mold to form a molded part; and removing the mold from the mold part by breaking the mold from the molded part via a breakaway feature defined by the porosity of the mold.
In some examples, the controlling of the fusion level includes: identifying a pattern of the mold to be formed via the additive manufacturing process; distributing the build material on a support bed to define a first layer of the mold in accordance with the pattern; dispensing a first amount of fusing agent on the build material; dispensing a second amount of detailing agent on at least a portion of the build material or the fusing agent; and applying an energy to the build material and fusing agent to solidify the first layer, and defining the porosity of the first layer in accordance with the target porosity, by varying at least one of: the first amount of the fusing agent; the second amount of the detailing agent; or the amount of the energy.
In some examples, a tangible computer readable storage medium comprising instructions which, when executed, cause a processor to at least: receive an image representative of a 3D printed mold; determine a target porosity of the 3D printed mold; and for individual layers of the 3D printed mold: determine an amount of build material to be dispensed by a build material dispenser of a 3D printer; and define a porosity of the individual layers in accordance with the target porosity, by determining at least one of: a first amount of a fusing agent to be dispensed by a fusing agent dispenser of the 3D printer; a second amount of detailing agent to be dispensed by a detailing agent dispenser of the 3D printer on at least a portion of the build material or the fusing agent; or an amount of energy to be applied to the build material, the fusing agent and the detailing agent, via an energy source of the 3D printer.
In some examples, the instructions, when executed, cause the processor to instruct the fusing agent dispenser to dispense the determined first amount of the fusing agent, instruct the detailing agent dispenser to dispense the determined second amount of detailing agent, and instruct the energy source to apply the determined amount of energy to the build material, the fusing agent and the detailing agent.
In some examples, a method for forming a mold having a cavity by creating a plurality of layers using an additive manufacturing process includes: identifying a pattern of a mold to be formed via an additive manufacturing process; determining a target porosity; distributing a build material on a support bed to define a first layer of the mold; dispensing a first amount of fusing agent on the build material; dispensing a second amount of detailing agent on at least a portion of the build material or the fusing agent; and applying, via an energy source, an energy to the build material and fusing agent to solidify the first layer; where the dispensing of the first amount of suing agent, the second amount of the detailing agent or the applying of the energy includes varying at least one of the first amount of the fusing agent, the second amount of the detailing agent, or a third amount of the energy to define a first porosity of the first layer in accordance with the target porosity.
In some examples, the method further includes distributing the build material on the first layer of the mold to define a second layer of the mold; dispensing the first amount of the fusing agent on the build material of the second layer of the mold in accordance with the target porosity; and applying energy, via an energy source, to the fusing agent to fuse the build material and solidify the second layer of the mold, the second layer having the first porosity.
In some examples, the method includes distributing the build material on the first layer of the mold to define a second layer of the mold; dispensing a fourth amount of the fusing agent on the build material of the second layer of the mold; dispensing a fifth amount of the detailing agent on at least one of the build material or the fusing agent; applying energy, via an energy source, to the fusing agent to fuse the build material and solidify the second layer of the mold; and varying at least one of the fourth amount of the fusing agent, the fifth amount of the detailing agent, or a sixth amount of the energy to define a second porosity of the second layer in accordance with the target porosity.
In some examples, a workstation for printing a 3D printed mold via a plurality of layers includes: a build material dispenser to dispense a build material on a support bed; a fusing agent dispenser to dispense a fusing agent on the build material; and a controller to: receive a print command representative of the 3D printed mold; determine a target porosity of the 3D printed mold; and for individual layers of the 3D printed mold: cause the build material dispenser to dispense the build material; cause the fusing agent dispenser to dispense an amount of the fusing agent on the build material, the amount of the fusing agent corresponding to the target porosity; and control an energy source to apply energy to the build material and the fusing agent to form the individual layers with a porosity that is based on the target porosity.
In some examples, the amount of the fusing agent is to cause the individual layers of the 3D printed mold to form as an under-fused powder layer.
In some examples, the porosity across a surface area or volume of the individual layers varies within a porosity range.
In some examples, the porosity range is between approximately 2 percent and 45 percent.
Although certain example methods, apparatus and articles of manufacture have been disclosed herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the claims of this patent.
Filing Document | Filing Date | Country | Kind |
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PCT/US2018/066015 | 12/17/2018 | WO | 00 |