3D printing processes continually improve and have evolved beyond just SLA (stereolithography) and the widely-used FDM (fused deposition modeling). There has been progress in accuracy, feature complexity, and supporting software in recent years for all types of 3D printing. The most significant advancements have come with the introduction of DLP (digital light processing). The capabilities of DLP printers allow for faster manufacturing of products like dental appliances, medical devices, and footwear and enable improvements in design and quality. DLP offers faster production speed, better surface finish, and isotropic material properties.
What is DLP 3D Printing?
DLP 3D printers fabricate products on a build platform above a vat of photosensitive resin. A DLP chip projects a cross-sectional image of a print layer onto the resin, hardening the exposed material. The platform slowly rises vertically from the resin vat and builds each layer. All points in each layer cure simultaneously, resulting in a much faster layer printing than traditional printing methods using tracing. Once printing is complete, support structures are removed — if any, and the part is washed and cured.
Benefits of Advanced DLP 3D Printing Solutions
DLP 3D printing solutions are advancing faster than other 3D printing technologies because leading companies are taking a holistic approach – 3D printing machines, software, and materials. The following benefits are why companies see DLP as the better choice to produce their products.
Smooth Surface Finish with Digital Polishing™
DLP 3D printers can achieve the smoothest surface finish of all 3D printing processes with Digital Polishing™, an advanced printing technique that combines 3D printing software and material that is tuned to the machine. DLP printers produce features as fine as .05 mm with no lines and can support a variety of surface finishes with more complex geometries.
Reducing Post-Processing
DLP 3D printers require significantly less post-processing than other 3D printers. DLP prints highly accurate products that require washing and curing steps and eliminates excessive polishing and machining for high-performance parts. It also requires only minimal removal of support structures.
High Throughput with Rapid Speed and Large Area Printing
DLP cures all layers simultaneously, resulting in faster printing than area tracing processes. Concurrent curing allows for faster printing of both small and large batches. DLP 3D printers, when compared to standard 3D printers, produce large, dense parts quicker.
Elastic Printing
There is now a wide range of materials supported by DLP printers. Advanced DLP 3D printing solutions can print high viscosity elastic resins, creating products that can surpass equivalent ones made with traditional manufacturing materials like foam.
Clear or Transparent Printing
Printing clear parts have been a challenge for additive manufacturing. With a holistic approach, DLP 3D printing can easily print clear or colored transparent parts. For dental, clear printing simplifies aligner production to just scanning a patient’s mouth and directly printing a clear aligner, eliminating intermediate steps for thermoforming.
Directly Printing Colored Parts
Many companies that leverage 3D printing use the default resin color or dye the part to the desired color. DLP 3D printing is transforming the consumer industry by directly printing colored products. For example, an eyewear company is scanning patient faces and using DLP 3D printing to rapidly produce custom eyewear frames in a wide range of colors, including transparent colored frames. Leading footwear companies are directly printing footwear products or parts in a specific color.
DLP Printers with LEAP™ Technology
All LuxCreo DLP 3D printers utilize LuxCreo’s patented LEAP™ (Light Enabled Additive Production) technology. LEAP™ technology incorporates software, resin tuning, and materials for even better surface finish, accuracy, and performance than other DLP 3D printers. LEAP™ technology also allows LuxCreo’s DLP 3D printers to print fully clear parts with post-processing requiring only washing and curing steps without reducing layer thickness. LuxCreo’s DLP 3D printers allow for 90% material and labor savings to reduce excessive machining, post-processing, and material waste. Additionally, DLP 3D printers with LEAP™ technology print elastic materials better than other DLP 3D printers for smoother, more accurate, and translucent parts.
DLP Vs. FDM and SLA
The benefits and drawbacks of DLP are often discussed in comparison to fused deposition modeling (FDM) and stereolithography (SLA).
Fused Deposition Modeling (FDM)
An FDM 3D printer extrudes a thermoplastic filament through an aperture while tracing the part’s structure on a horizontal platform. As the printer head traces the cross-section, the filament is heated, melting and depositing the material. The deposited material quickly cools and hardens. The market considers FDM line-by-line tracing the slowest process and requires significant post-processing, such as sanding, to deliver the final part.
Stereolithography (SLA)
In stereolithography, a laser scans over a wet bath of thermosetting resin to form a layer of hardened material. Within the resin bath, a platform moves down by one layer thickness, and the laser scans over the material again to create the next layer. As this process continues, the hardened resin forms a part.
The chart below highlights the benefits and drawbacks of each 3D printing process:
| DLP | SLA | FDM | |
| Build Volume | Supports fast layer by layer printing with small and medium build volumes. Larger build volumes are becoming possible with multiple projectors. | Supports small and large build volumes but is slow due to the tracing process and extrusion limitations. | Supports small and large build volumes but is slow due to the tracing process and extrusion limitations. |
| Surface Finish | DLP printers produce highly accurate, complex geometries with a variety of surface textures. New LuxCreo LEAP DLP innovation enables Digital Polishing™, eliminating polishing steps required to achieve transparent parts. | A laser traces outside contours giving excellent detail. The size of the laser spot determines the minimum feature size. This size is in the range of .03 mm to .15 mm. However, spot beams are as large as .08 mm, and surfaces require extensive polishing for transparency. | FDM requires significant post-processing, including CNC machining and chemical vapor smoothing, to remove out layer lines and drill out support structures to achieve smooth hole features. It is limited to simplified models and geometries. |
| Accuracy | DLP is comparable to SLA in deposition accuracy achieving 0.02mm (xy) and 0.01 (z) accuracy. | SLA is comparable to DLP in deposition accuracy. However, spot beam angle and size limit feature size. | FDM has lower accuracy depending on nozzle aperture size and printer design quality. |
| Speed | Fast; DLP generally prints faster, curing an entire layer at once, eliminating the time needed to scan the part’s interior, as seen in SLA printing. More parts in a batch and part complexity do not require more time. DLP can print in minutes for what takes SLA and FDM hours and days. | Slow, high-resolution laser point that creates the fine exterior faces now becomes the limiting factor in curing the interior fill areas. More parts in a batch take more time. | Slow; large parts can take days to print. Batch printing time slows for full batches having to trace each part cross-section in series. A 190 x 120 x 380 solid box will print in 133 hours, up to .3 cm per hour on FDM printing (printer dependent). |
| Post-Processing | Advanced DLP solutions are now reducing post-processing workflow steps. New LuxCreo LEAP DLP innovation enables Digital Polishing™, eliminating polishing steps required to achieve transparent parts. | Continues to require significant post-processing steps to achieve clarity and smooth surfaces. | Requires significant post-processing (i.e., support removal, tumbling, vapor smoothing, and machining) to remove support structure, achieve dimensional accuracy, and ensure surface finish comparable to DLP. |
| Materials | High-performance resins printed on production-grade DLP printers are leading the 3D printing space in elastic and dental applications outperforming SLA, FDM, SLS, and traditionally manufactured materials. | SLA resins options are extensive; however, the slow high, intensity laser tracing process limits final product performance. | Primary materials include thermoplastics with various properties from rubbery to rigid, including TPUs, ABS, and polycarbonate. |
Each printing process offers unique advantages suited to specific product applications. Understanding the advantages and limitations will help companies better decide if DLP 3D printers will support their manufacturing process.
Choosing a 3D Printing Partner
With the right 3D printing technology partner, companies can determine the best materials, processes, and designs to ensure optimum 3D printing yields. Whether using in-house 3D printing processes or outsourcing for easier scalability, working with a leading 3D printing company can help enhance and fine-tune the process.
Advanced companies like LuxCreo offer smart-factory access to cloud-connected DLP 3D printers for on-demand production and market flexibility without the steep initial costs of traditional manufacturing. Smart factories offer a fast, low-risk option for low or high-volume manufacturing, prototyping, and full-scale production.
LuxCreo’s DLP 3D printers with patented LEAP™ (Light Enabled Additive Production) process offer the ideal 3D printing process to help you scale. We offer smart factory-connected 3D printers, high-performance materials, and on-demand Smart Factory production service for low and high-volume manufacturing and rapid prototyping applications. For more information on how our services can improve manufacturing, visit our contact us page or call (650) 336-0888.
