Mar 19
The 3D Printing Revolution: How Additive Manufacturing is Reshaping Industries
WHAT IS ADDITIVE MANUFACTURING?
Additive manufacturing (AM), also known as 3D printing, is a transformative approach to industrial production that enables the creation of lighter, stronger parts and systems. It is a process used to create a physical (or 3D) object by layering materials one by one based on a digital model. Unlike subtractive manufacturing which creates its final product by cutting away from a block of material; additive manufacturing adds parts to form its final product. AM can bring digital flexibility and efficiency to manufacturing operations.
Additive manufacturing uses data computer-aided design (CAD) software or 3D object scanners to direct hardware to deposit material, layer upon layer, in precise geometric shapes. As its name implies, additive manufacturing adds material to create an object. By contrast, when you create an object by traditional means, removing material through milling, machining, carving, shaping or other means is often necessary. Additive manufacturing can encompass multiple processes, depending on the hardware, material requirements, and product application.
TYPES OF ADDITIVE MANUFACTURING
Additive manufacturing can encompass multiple processes, depending on the hardware, material requirements, and product application.
VAT PHOTOPOLYMERIZATION
A vat of photopolymer liquid is cured by focused UV light that builds parts layer by layer for a high-detail surface finish.
BINDER JETTING
A power substrate is hardened when the printing head deposits a drop of binding fluid in a layering process. Includes full-color prototype fabrication.
MATERIAL JETTING
Primarily used where surface finished and form testing is needed; a printhead lays down successively solidifying layers of UV-curable material to form prototyped designs.
MATERIAL EXTRUSION
Fused deposition modeling is a typical 3D printing process in which a heated nozzle extrudes a plasticized material to form products from a sliced CAD model.
POWDER BED FUSION
Laser or electron beams rapidly fuse layered powder material, such as various metals, together. Used for circuits, structures, and parts.
SHEET LAMINATION
Ribbons of metal or paper are bonded through ultrasonic welding or adhesive, respectively; the finished shaping is completed through further material removal processes.
DIRECTED ENERGY DEPOSITION
Repairs or adds to existing components by using a multi-axis nozzle to extrude laser-melted material, commonly metal powders, onto the printing surface.
METAL CASTING
Using generative design and simulation software to produce complex metal parts helps manufacturers get more value from proven metal casting processes.
PROCESSES INVOLVED IN ADDITIVE MANUFACTURING
1. CAD
Producing a digital model is the first step in the additive manufacturing process. The most common method for producing a digital model is a computer-aided design (CAD). There is a large range of free and professional CAD programs that are compatible with additive manufacturing. Reverse engineering can also be used to generate a digital model via 3D scanning.
There are several design considerations that must be evaluated when designing for additive manufacturing. These generally focus on feature geometry limitations and support or escape hole requirements and vary by technology.
2. STL conversion and file manipulation
A critical stage in the additive manufacturing process that varies from traditional manufacturing methodology is the requirement to convert a CAD model into an STL (stereolithography) file. STL uses triangles (polygons) to describe the surfaces of an object. A guide on how to convert a CAD model to an STL file can be found here. There are several model limitations that should be considered before converting a model to an STL file including physical size, water tightness, and polygon count
Once an STL file has been generated the file is imported into a slicer program. This program takes the STL file and converts it into G-code. G-code is a numerical control (NC) programming language. It is used in computer-aided manufacturing (CAM) to control automated machine tools (including CNC machines and 3D printers). The slicer program also allows the designer to customize the build parameters including support, layer height, and part orientation.
3. Printing
3D printing machines often comprise many small and intricate parts so correct maintenance and calibration are critical to producing accurate prints. At this stage, the print material is also loaded into the printer. The raw materials used in additive manufacturing often have a limited shelf life and require careful handling. While some processes offer the ability to recycle excess build material, repeated reuse can result in a reduction in material properties if not replaced regularly.
Most additive manufacturing machines do not need to be monitored after the print has begun. The machine will follow an automated process and issues generally only arise when the machine runs out of material or there is an error in the software. An explanation of how each of the different additive manufacturing printers produces parts can be found here.
4. Removal of prints
For some additive manufacturing technologies removal of the print is as simple as separating the printed part from the build platform. For other more industrial 3D printing methods the removal of a print is a highly technical process involving precise extraction of the print while it is still encased in the build material or attached to the build plate. These methods require complicated removal procedures and highly skilled machine operators along with safety equipment and controlled environments.
5. Post-processing
Post-processing procedures again vary by printer technology. SLA requires a component to cure under UV before handling, metal parts often need to be stress relieved in an oven while FDM parts can be handled right away. For technologies that utilize support, this is also removed at the post-processing stage. Most 3D printing materials are able to be sanded and other post-processing techniques including tumbling, high-pressure air cleaning, polishing, and coloring are implemented to prepare a print for end use.
APPLICATIONS:
LIGHTWEIGHT COMPONENTS
One of the earliest ways to use additive manufacturing for industrial purposes, this practice is now becoming an industry standard. CAD-to-additive simulation technology is improving exponentially
CUSTOM TAILORED COMPONENTS
Additive engineering provides the flexibility that manufacturers need to deliver custom solutions to clients quickly.
ON-DEMAND PRODUCTION
Prototyping is the original use of additive manufacturing. Though it is still widely used for that purpose, many companies succeed in delivering reliable 3D-printed finished goods.
TRENDS IN ADDITIVE MANUFACTURING
Additive manufacturing has evolved rapidly in recent years. It has been embraced by major industrial companies looking to improve their products. The ability to deliver near-instant parts production and fully custom designs that cannot be replicated with other manufacturing techniques has accelerated investment and research in additive engineering.
We hope you found this article informative and insightful. It was contributed by Sanniva Bhattacharjee. If you’re passionate about technology and have unique insights to share with our community, we welcome your contributions. Simply mail your article to blog@istenitdgp.com, and you could see it featured on our social media handles.
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