GUIDE
Introduction
Having been involved with 3D printing for a while, I’ve noticed that many enthusiasts get confused by the myriad of technical terms when they first start. For instance, when I took a junior colleague to visit a local 3D printing service provider this week, I intended to act like an expert, but I ended up being stumped by her questions about FDM, SLA, SLS, and so on. So today, I’ll break it down in a more relatable way.
To begin with: The debate over technical routes in the additive manufacturing community has been ongoing for a long time, much like martial arts sects, each with its own unique skills and followers. Essentially, these technologies all involve “layering,” but the methods and materials used for “stacking” vary significantly.
1
The National-Level “Little Desk Lamp” — FDM
Professional Definition:Material Extrusion (MEX) is a typical representative, where thermoplastic filament is heated to a molten state and extruded layer by layer through a fine nozzle along a specified path, cooling and solidifying to form a three-dimensional object.
In Layman’s Terms:With the scent of PLA wafting through the air, the 200 °C hot end extrudes filament like noodles, reminiscent of a late-night diner. It’s cheap, durable, and changing colors is as easy as changing a game skin. Students use it to print figurines, factories print fixtures at night, and no one complains. Drawbacks? Layer lines resemble tree rings, precision is ±0.1 mm at best, and achieving a mirror finish requires sandpaper and skilled hands.
Representative Players
Stratasys:The pioneer, with industrial-grade F900 and F3300 models costing as much as a BMW, standard for aerospace interior fixtures.
Topworks Technology:A “performance monster” among desktop machines, the X1 Carbon achieves printing speeds of 300 mm/s and includes a laser radar for automatic leveling, offering industrial-grade experience at consumer-level prices.
Suwei Technology:A domestic giant in large-scale printing, the D1000 Pro2 HS has a build volume of 1 m³, capable of high-speed printing with PEEK, and utilizes a domestic Klipper solution that outperforms foreign counterparts.
2
The “Beauty Camera” of the Resin Faction — SLA/DLP/LCD
Professional Definition:Vat Photopolymerization (VPP) uses specific wavelength ultraviolet light to scan liquid photosensitive resin layer by layer, causing free radical polymerization and solidification.
In Layman’s Terms:The three brothers of photopolymerization use UV light to turn liquid resin into solid. SLA draws with a laser, taking its time for fine details; DLP works like a projector, exposing a layer in seconds; LCD is even more aggressive, using a whole screen as a light source, making it incredibly cost-effective. The surface finish is leagues ahead of FDM, making it beloved by dental, jewelry, and figurine manufacturers. The only deterrent is the smell — the moment the lid is opened, office colleagues flee.
Representative Players
3D Systems: The SLA leader, with the Figure 4 series pushing resin printing speeds to “minute” levels, keeping dental factories running 24/7.
Creality: Their desktop LCD printers have astonishing sales, with the HALOT series offering 4K monochrome screens at around $200, making them accessible for students.
Elegoo: The Saturn and Jupiter series dominate the figurine market with their large sizes and low prices, even resin manufacturers buy them for prototyping.
3
The Powdered Realm — SLS/SLM/EBM
Professional Definition:Powder Bed Fusion (PBF) involves selectively melting metal or polymer powders using lasers or electron beams in a high-purity inert atmosphere or vacuum, achieving nearly 100% density through layer stacking (SLM, EBM).
In Layman’s Terms:Switching to the metal battlefield, the atmosphere instantly becomes “Game of Thrones.” SLS uses lasers to “burn” nylon powder, providing built-in support and allowing for intricate hollow structures; SLM directly melts metal, achieving over 99% density, essential for aerospace engine blades and rocket nozzles; EBM replaces lasers with electron beams, creating sparks in a vacuum chamber, making titanium alloys behave like magic, reducing warping and increasing speed.
Representative Players
EOS: A German veteran, the M 290 has become the “textbook” for metal printing, with the highest usage in aerospace.
SLM Solutions: A multi-laser powerhouse, the NXG XII 600 features 12 laser beams, increasing printing speed by ten times compared to single-beam systems, used by Tesla and GE.
Huazhu High-Tech: A domestic star, the Flight series achieves 500 W fiber laser power, even exporting to Germany at a premium, showcasing strength.
Platinum Technology: The first publicly listed company in China for metal 3D printing, offering a full range of services from equipment to printing, with numerous production cases.
4
Binder Jetting — The Cost-Saving Hybrid of “Inkjet + Oven”
Professional Definition:Binder Jetting (BJT) deposits liquid binder onto a powder bed using piezoelectric nozzles, forming a green part, which is then sintered after debinding to obtain the final component.
In Layman’s Terms:Think of metal/ceramic powders as paper and the binder as ink; first, print the green part, then sinter it in the oven. Advantages: Equipment is cheap, and the speed is impressive, allowing for mass production of colored sandstone models and pump impellers, reducing costs by 30%. Disadvantages: Density still lags behind SLM, mechanical properties are lacking, making it unsuitable for aerospace applications, but it’s great for automotive repairs.
Representative Players
ExOne (now under Desktop Metal): Dual focus on metal and sand casting, with S-Max sand printing transforming traditional foundries into “moldless” factories.
HP: The Jet Fusion 5200 series achieves micron-level porosity control in nylon BJT, enabling mass production of automotive conduits and connectors.
5
Directed Energy Deposition — The Hybrid of “Welding + 3D”
Professional Definition:Directed Energy Deposition (DED) uses high-energy heat sources such as lasers, electron beams, or plasma arcs to simultaneously melt metal powders or wires, depositing them layer by layer for near-net shaping or remanufacturing.
In Layman’s Terms:Lasers or electron beams spray powder (or wire) while moving, creating a molten pool that coats parts like a “metal down jacket.” The biggest selling point: repair! Did an aerospace engine blade get chipped? Just “fill it in” on-site, saving 90% of the material compared to remelting. The downsides are clear: the surface resembles old tree bark, requiring traditional machining for a second “beautification”.
Representative Players
Optomec: The pioneer in laser powder delivery, the Lens series specializes in repairing aerospace blades, a trusted partner on GE and Rolls-Royce production lines.
BeAM Machines: A rising star from France, offering both wire and powder delivery modes, providing on-site “meat filling” for nuclear power valves, saving 90% of materials.
6
Sheet Lamination — The “Paper Cutting” Artist
Professional Definition:Sheet Lamination (SHL) involves bonding metal or composite material foils layer by layer through ultrasonic welding, hot pressing, or adhesive methods, followed by contour cutting or milling to form a three-dimensional object.
In Layman’s Terms:Layering adhesive-coated paper/plastic/metal foils and cutting the contours with lasers or blades sounds retro, but it can stack carbon fiber and glass fiber prepregs into composite parts, achieving strength that surpasses ordinary plastics. The downside is high waste and average precision; it has lost some spotlight to multi-material printing but still holds a place in non-metal reinforcement fields.
Representative Players
Fabrisonic: The only player in ultrasonic additive manufacturing (UAM), bonding aluminum, copper, and titanium together, used by NASA for integrated structures with embedded sensors.
7
Area Printing/Multi-Beam — The “Future Disruptor”
Professional Definition:Still within the PBF framework, but utilizing multi-beam arrays or large-area exposure to achieve “one-layer-at-a-time” melting, significantly reducing inter-layer time, classified as a branch of High-Speed PBF.
In Layman’s Terms:Traditional SLM uses one or two laser beams, while new players deploy hundreds of beams, flooding the powder bed with energy like stage lights; Seurat even claims a target of “$25 per kilogram” for metal parts.
Representative Players
Seurat: The leader in area laser melting (Area Printing), using 2 million laser pixels to “expose” a layer simultaneously, aiming to produce stainless steel parts at $25/kg.
AddUp: (a joint venture between Michelin and Fives): Multi-beam + closed-loop control, currently testing mold inserts with major automotive manufacturers, claiming a 5-fold increase in printing speed.
8
Solid-State Additive — The “Non-Melting” Cold Killer
Professional Definition:Solid-State Additive Manufacturing (Solid-State AM) uses mechanical friction or ultrasonic vibration below the material melting point to induce plastic deformation and atomic-level bonding, avoiding melting defects.
In Layman’s Terms:No lasers or electron beams are needed; just “friction heating + hard pressing” can layer metal foils or rods together. Without a molten pool, there are no gas pores or cracks, allowing for welding of high-melting-point alloys and dissimilar materials. The downside is that the equipment is newly commercialized, and the component sizes are still small; currently, the main visible technologies in China are ultrasonic additive manufacturing (UAM) and friction stir deposition (FSAM).
Representative Players
Fabrisonic: Previously mentioned, the only player in UAM;
MELD Manufacturing: Friction stir deposition (FSD) technology can print aluminum/magnesium/steel in open environments, used by the U.S. Navy for on-site “meat filling” of naval gun parts.
9
Hybrid Manufacturing — The “Six-Sided Warrior” of “Left and Right Fighting”
Professional Definition:Hybrid Additive Manufacturing (Hybrid AM) integrates additive and subtractive (milling, grinding) or forming (rolling, forging) functions on the same machine tool, achieving a “printing-processing-heat treatment” closed-loop manufacturing.
In Layman’s Terms:After printing, it goes directly to five-axis milling, completing the process in one go. Precision improves from ±0.1 mm to ±0.01 mm, and surface Ra can reach ≤0.8 µm, eliminating repeated positioning errors from re-clamping. The downside is that the equipment is prohibitively expensive; a Hybrid 5-axis machine can cost as much as three Model S cars, but aerospace precision molds and hydraulic valve bodies are already quietly using it to “disrupt” traditional processes.
Representative Players
DMG Mori: Completing laser deposition and five-axis milling in one machine, the LASERTEC 65 3D combines “printing + precision milling,” saving two outsourcing steps for automotive die casting.
Hamuel Maschinenbau: Specializing in wire DED + milling, already operating 24/7 unattended in German factories for aerospace structural components.
In conclusion, I find that the 3D printing community resembles the world of martial arts: numerous sects, each practicing their own skills, occasionally borrowing from one another. Ultimately, the debate over technical routes is a false proposition. A seasoned player in the printing service industry once said it best: “Customers don’t care what technology you use; they only care if you can solve their problems and how much it will cost.”
WeChat Group 1: A talent exchange group with over 200 members, welcoming HR and industry elites from various companies to join.
WeChat Group 2: A 3D printing industry chain group, gathering upstream and downstream manufacturers for convenient industry communication.