Five common 3D printing processes: Why is FDM the easiest to get started?
3D printing (additive manufacturing) builds objects by depositing materials layer by layer. Different molding techniques determine printing accuracy, speed, and applicable scenarios. Below are five of the most popular 3D printing molding technologies, providing a quick introduction in layman's terms.
1. Fused Deposition Modeling (FDM): The Easiest to Use "Filament Extrusion"
Technology FDM, like "creaming with icing cream," is the most commonly used technology for home and entry-level users. It forms the material into a filament, feeds it through a heated nozzle (180-260°C) to melt it into a liquid, and then extrudes it along a designed path.
After cooling, the material bonds together into layers, which are then stacked to create a model.
This technology is very easy to get started with.Desktop printers cost only a few thousand yuan, and operation is simple, allowing even beginners to master it by following the tutorial. However, accuracy is generally average, and the finished product may have "stepping" patterns on the surface. It is suitable for making educational aids, figurines, simple part prototypes, and other items that do not require high precision.
2. Stereolithography (SLA): High-Precision "Laser Engraving"
Technology SLA focuses on high precision, using liquid resin as the raw material and shaping it with ultraviolet lasers. It is the industry's earliest, most mature, and most widely used 3D printing technology. A laser beam scans the resin surface point by point, instantly solidifying the exposed resin into a layer of cross-section. After each layer is completed, the platform descends slightly to scan the next layer, ultimately stacking up to create a detailed model.
It offers extremely high precision, with a minimum layer thickness of 0.016mm. The finished product has a smooth surface and can reproduce even the smallest details, such as jewelry textures and dental models. However, the equipment and material costs are high, and the resin is slightly toxic, requiring proper protection when handling. It is primarily used for applications such as precision part prototypes and jewelry wax models.
3. Digital Light Processing (DLP): Fast, batch "projection curing" technology
DLP is recognized as the second-generation stereolithography technology in the industry, with a history of over 20 years. DLP and SLA work on similar principles, but instead of using laser point scanning, a projector-like device projects an entire cross-sectional pattern onto the resin surface, curing the entire layer simultaneously.
This "whole-layer printing" method is 3-5 times faster than SLA and is suitable for small-batch production. It offers comparable precision and reduces light source maintenance costs. It is commonly used in high-efficiency printing applications, such as mass-customized dental restorations (such as crowns) and microelectronic component housings.
4. Selective Laser Sintering (SLS): A "powder sintering" technology capable of creating complex structures.
SLS uses powdered materials (such as nylon or metal powders) by first applying a thin layer and preheating to near their melting point. A high-powered laser is then scanned over the target area, melting and sintering the powder into a single layer. The unsintered powder naturally acts as support, eliminating the need for additional support structures.
It can print complex hollow and hollow structures, such as lightweight aerospace parts, and offers high material efficiency (unsintered powder is recyclable). However, the equipment is expensive (industrial-grade parts can exceed one million yuan) and the printing speed is relatively slow. It is primarily used for industrial-grade functional parts and high-end prototyping.
5. Layered Object Manufacturing (LOM): A Layered Molding Technology Like "Slicing Bread"
LOM's principle is similar to "slicing bread layer by layer and then gluing them together." Using thin layers of material like paper or plastic film, LOM is first coated with hot melt adhesive, then laser-cut to create the cross-sectional outline. New layers are then applied and heat-bonded. This process is repeated to create the final product, and any excess material can be simply peeled off.
It boasts fast molding speeds, can produce large models, and requires no additional support design, keeping costs manageable. However, its precision is low, its surface has a layered texture, and its material strength and weather resistance are poor. It is therefore suitable for items with low strength requirements, such as architectural models, display prototypes, and film and television props.
These five technologies each have their own strengths: FDM is suitable for beginners, SLA/DLP focuses on precision, SLS excels at complex structures, and LOM is more advantageous for producing large, low-cost display models. Choosing the right technology for your needs will allow 3D printing to better serve both your daily life and production.
