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MJF – MultiJet Fusion

For more than 30 years, HP inkjet technologies have disrupted and led a broad range of printing markets. HP MJF – Multi Jet Fusion technology leverages HP’s deep assets in imaging and printing to take the digital transformation of printing off the page and into a three-dimensional world of highly-functional, high-value manufactured items.

HP Multi Jet Fusion technology offers high build quality at up to 10 times the speed3 and at the lowest cost relative to competitive 3D printing solutions in the marketplace today. These breakthroughs in quality and speed will accelerate the widespread adoption of 3D printing to create a digital transformation of manufacturing as widespread and profound as the way HP Thermal Inkjet has changed the landscape of conventional printing markets and applications. As with other HP products, HP Jet Fusion 3D Printers will offer users HP’s key values of reliability, ease of use, versatility, and an end-to-end digital workflow.

Read on for a summary or download HP’s Full White Paper on MJF – MultiJet Fusion Technology

HP Multi Jet Fusion was conceived to overcome the tradeoffs and constraints limiting current 3D technologies. And, HP Multi Jet Fusion has the unique ability to produce parts with controllable physical and functional properties at each point in a part. Offering speed, quality, strength, and novel functionalities, HP Multi Jet Fusion will accelerate the adoption of 3D manufacturing across a wide range of industries and applications.

HP’s vision is to revolutionize part design and manufacturing with streamlined workflows and new capabilities for 3D printing. The supply chain for finished, high-value items will be fundamentally changed by the ability to manufacture parts where they are needed and on-demand. HP’s Multi Jet Fusion Open Platform will bring down barriers to adoption of 3D printing through collaborative innovations in materials, printing hardware, and design and production software.

HP Post Processing Station with Fast Cooling accelerates parts cooling time versus recommended manufacturer time by SLS printer solutions from $100,000 USD to $300,000 USD, as tested in April 2016. FDM not applicable. Continuous printing requires an additional HP Jet Fusion 3D Build Unit (standard printer configuration includes one HP Jet Fusion 3D Build Unit). Based on internal testing and simulation, HP Jet Fusion 3D average printing time is up to 10x faster than FDM and SLS printer solutions from $100,000 USD to $300,000 USD on market as of April 2016. Testing variables: Part Quantity-1 full build chamber of parts from HP Jet Fusion 3D at 20% of packing density vs. same number of parts on above-mentioned competitive devices; Part Size 30 g; Layer thickness: 0.1 mm/0.004 inches.

Based on internal testing and public data, HP Jet Fusion 3D average printing cost-per-part is half the cost of comparable FDM and SLS printer solutions from $100,000 USD to $300,000 USD on market as of April 2016. Cost analysis based on: standard solution configuration price, supplies price, and maintenance costs recommended by manufacturer. Cost criteria: printing 1-2 build chambers per day/ 5 days per week over 1 year of 30-gram parts at 10% packing density using the powder reusability ratio recommended by manufacturer.

MJF - multijet fusion

HP Multi Jet Fusion is built on decades of HP’s investment in inkjet printing, jettable materials, precision low-cost mechanics, material science, and imaging. With custom materials and innovations in how a large working area can be printed and cured rapidly, HP Multi Jet Fusion delivers advantages in build speed and control over part and material properties that are beyond the capabilities of other 3D printing processes. By jetting HP functional agents using HP printheads, material in the working area can be fused, detailed, and transformed point-by-point.

A key innovation in HP Multi Jet Fusion is a high-speed, synchronous architecture that builds parts layer-by-layer. As shown schematically in Figure 1, dual carriages scan across the Working area in perpendicular directions: one carriage recoats the working area with fresh material, and the other prints HP functional agents and fuses the printed areas. This separates the processes of recoating and printing/fusing so that each process can be separately optimized for performance, reliability, and productivity.

In an HP Jet Fusion 3D Printer, a part, or a set of parts, is built layer-by-layer over a working area inside an HP Jet Fusion 3D Build Unit. After job completion, the build unit is rolled into an HP Jet Fusion Processing Station for cooling, unpackingtheparts,andrecoveryandrefreshingthebuildmaterial.6 Whilethoseprocessesarecompleting,abuild unit that has been refreshed by the HP Jet Fusion Processing Station can be rolled back into the printer for continuous production. 7

The depth of the build unit and working area determine the dimensions of the largest part that can be produced. For example, HP Jet Fusion 3D 4200 and 3200 printers have a working area of 16H X 16W X 12D inches (406H X 406W X 305D mm) for a build volume of 3072 cubic inches (50 liters). For specifications on processing speed and working area for HP Jet Fusion 3D Printers, consult product data sheets at hp.com/go/3Dprint.

HP Multi Jet Fusion uses scalable HP Thermal Inkjet technology to make printbars of different widths by stacking printheads across the width of the scan. Just as this capability allows HP to scale its 2D printing solutions from the desktop to more than 100 inches wide, HP can create a range of HP Jet Fusion 3D printing solutions with working areas of different sizes. HP printheads can also be stacked along the scan direction to add more nozzles for speed, functionality, and nozzle redundancy for dependable printing quality.

Building parts by HP MJF – Multi Jet Fusion

The build begins by laying down a thin layer of powdered material across the working area. For example, in Figure 1, the material recoater carriage scans from top-to-bottom. Next, the printing and fusing carriage with an HP Thermal Inkjet (printhead) array and energy sources scans from right-to-left across the working area. The leading energy source preheats the working area immediately before printing to provide consistent and accurate temperature control of each layer as it is printed. The printheads now print functional agents in precise locations onto the material to define the

Fast Cooling is enabled by HP Jet Fusion 3D Processing Station with Fast Cooling, available in April 2017. Material handling includes automated mixing of fresh and recycled powder, sieving, and loading. Consistent performance is achieved with reusing powder with a 20% powder refresh rate. At the ends of the scans, supply bins refill the recoater with fresh material and service stations can test, clean, and service the printheads on the printing and fusing carriage as needed to ensure reliable operation. After finishing each layer, the surface of the work area retracts about the thickness of a sheet of office paper,8 and the material recoater carriage scans in the reverse direction for optimum productivity.

The process continues layer-by-layer until a complete part, or set of parts, is formed in the build unit. With HP Multi Jet Fusion, each layer of a part is defined by an area that is fused (or transformed) surrounded by unfused powder. HP 3D High Reusability PA12 powder was designed to minimize powder waste and can be reused in a later build.

An analogy between printing pixels in a monochrome image and printing voxels by conventional 3D technologies highlights the advanced capabilities of HP Multi Jet Fusion. In a monochrome 2D printer, a pixel is either printed or not, and in conventional 3D printers a voxel is either fused or not. HP Multi Jet Fusion advances 3D printing in the same way that adding color to 2D inkjet printing expanded the capabilities, applications, and markets it could serve. In 2D printing, multiple inks—cyan, magenta, yellow, and black—can be combined in pixels to print an image with a wide range of colors. Using multiple agents, HP Multi Jet Fusion prints voxels with a range of physical and functional properties— including color.

MJF Transforming Agents

HP’s vision for HP Multi Jet Fusion technology is to create parts with controllably variable—even quite different— mechanical and physical properties within and across a single part or among separate parts printed simultaneously in the build unit. This is accomplished by the use of additional agents—called Transforming Agents—to control the interaction of the Fusing and Detailing Agents with each other and with the material to be fused. Depositing Transforming Agents voxel-by-voxel across each layer allows HP Jet Fusion 3D Printers to produce parts that cannot be made by other methods.

In HP Jet Fusion 3D Printers, properties that HP Transforming Agents could control within and across a part include

  • Dimensional accuracy and detail
  • Surface roughness, texture, and friction coefficient
  • Tensile Strength, elasticity, hardness, and other material properties

• Electrical and thermal conductivity • Opacity or translucency in plastics
• Color: embedded and at the surface

Using HP Transforming Agents to modify material properties, a part can have durable, hard surfaces with a low friction coefficient where contact and wear will occur, and different properties elsewhere to meet other functional requirements.

MJF - MultiJet Fusion

The ability of HP Transforming Agents to deposit conductive traces both embedded inside the part and on its surface offers the possibility of building intelligent parts that can measure and report their state during operation. For example, advanced HP Jet Fusion 3D Printers under development have built parts with embedded strain gage arrays— Wheatstone Bridges—that can accurately measure loads on the part during operation. This eliminates additional assembly operations, where strain gages must be precisely positioned and glued in place. Conductive traces can connect embedded and surface sensors with electronic circuits that process and report part status in real-time using visible indicators—such as light-emitting diodes—or by low-power wireless technologies.

HP’s first Jet Fusion 3D Printers use HP 3D High Reusability PA12, a strong, multi-purpose thermoplastic that optimizes buildcostandpartquality.9 WiththeHPMultiJetFusionprocess,thismaterialcanproducefunctionalpartswith excellentmechanicalproperties,10 highdimensionalaccuracy,2andfinedetail.HP3DHighReusabilityPA12isidealfor making parts with complex surfaces and internal shapes for housings, panels, enclosures, and connectors. And, it can make functional parts with moving subcomponents such as gears, rotational joints, and sliders.

HP is developing a family of thermoplastics for future generations of HP Jet Fusion 3D Printers that will include PA11, PA12 reinforced with glass beads, flame-retardant materials, and elastomers. Ceramics and other materials compatible with the HP Multi Jet Fusion process are also being investigated and developed. Excellent feature resolution, high dimensional accuracy, hardness, wear-resistance, high strength, and high solid density after sintering are objectives of HP’s advanced 3D materials development activities.

 

Materials

The HP Multi Jet Fusion Open Platform enables partners including Arkema, BASF, Lehmann&Voss&Co., Evonik, and others to participate in the development of new HP Multi Jet Fusion materials. With their experience and understanding of a broad range of customer needs and applications, these partners will accelerate the development and adoption of HP Multi Jet Fusion solutions, and offer manufacturing economies of scale that can reduce the cost of 3D printing supplies.

Software and workflow

The STL 3D file format, first developed in 1989 for the 3D printing solutions of that era, has shortcomings with long processing times and limited dimensional precision that pose barriers to the production of complex, high-precision parts by new technologies such as HP Multi Jet Fusion. STL cannot make use of the advanced capabilities of HP Multi Jet Fusion because it only allows geometric representations—and not a voxel-based description—to be sent from the CAD software to a 3D printer or other applications. To realize the full potential of 3D printing, new features and capabilities are needed in 3D CAD software, and this is an area where HP is actively contributing.

HP is a founding member of the 3MF Consortium,11 whose purpose is to define a new 3D printing format that allows 3D design software to communicate full-fidelity 3D models to other applications, services, and 3D printers.12 Industry leaders in 3D CAD, 3D printing, software companies, and selected customers are working together through the 3MF Consortium to develop a versatile and highly-capable 3MF file format.

 

HP 3D printing solutions include the HP SmartStream 3D Build Manager and HP SmartStream Command Center to prepare, send to print, and monitor 3D printing jobs. For part creation, HP offers 3D design software customized for HP Multi Jet Fusion from industry leaders Autodesk® (Autodesk® Netfabb® Engineer for HP) and Materialise Magics (Materialise Build Processor for HP Multi Jet Fusion).

Future potential

Just as HP’s traditional printing solutions evolved from inkjet-based desktop printers in the 1980s to HP’s high-speed commercial and industrial printing solutions of today, HP research and development will drive the evolution of HP Multi Jet Fusion technology beyond the materials and capabilities of HP’s first-generation 3D printing products. HP is investing in long-term efforts and collaborations through the HP Multi Jet Fusion Open Platform to deliver 3D printing solutions with advanced capabilities, materials and material handling, and optimized 3D manufacturing workflows.

HP Thermal Inkjet technology underlies the productivity and capabilities of HP Multi Jet Fusion. To get a sense of the potential and scalability of HP Thermal Inkjet in 3D printing, HP’s 2D printing solutions stack HP printhead modules to build printers with four, six, or more colors of ink and offer a wide range of printing formats from 1 inch to more than 100 inches wide. Using HP Thermal Inkjet, future HP Jet Fusion 3D Printers will be able to deliver more kinds of functional agents and build parts in working areas even larger than today.

Summary

HP Multi Jet Fusion is built on HP’s core competencies in precision low-cost mechanics, precision metering and placement of agents, high-volume manufacturing, material science, and imaging. Compared to other commercially available 3D printing technologies, HP Multi Jet Fusion and its 3D printing materials will define new levels of part quality, part functionality, and offer up to 10 times the build speed3 at the lowest cost.4

A unique feature of HP Multi Jet Fusion is its ability to modify material properties voxel-by-voxel to produce controlled- variability in mechanical and physical characteristics within and across a part. This capability enables a host of new possibilities in the design and function of parts that cannot be produced by traditional manufacturing methods or other 3D printing solutions.

HP’s entry into 3D printing will offer users a 3D printing ecosystem with advanced user interfaces, software for 3D part creation and production, and 3D printers optimized to deliver end-to-end productivity and economy that will drive the digital transformation of manufacturing.