DLP 3D printing (digital light processing 3D printing) is a UV additive manufacturing technique that cures entire layers of photopolymer resins and is used where speed of production is critical. DLP 3D printing offers detailed, intricate models that are used for a wide variety of applications, including prototypes, 3D printed jewellery, dentistry or medical devices.

The following article gives you a thorough overview of the innovative printing technique, its possibilities and what kind of photopolymer resins are needed to create the desired results.

DLP 3D printing (digital light processing 3D printing), along with others like material jetting, SLA printing, etc. is an additive manufacturing technique that uses light and photopolymers to create three-dimensional objects layer by layer.

The printing process uses a liquid photopolymer resin that hardens when exposed to light. A build platform is submerged or positioned just above a vat of the liquid photopolymer resin. The digital light projector shines UV light onto the resin, and the projected image corresponds to the first layer of the 3D object.

The areas of the photopolymer resin that are exposed to the UV light start to solidify or cure, while the uncured resin remains liquid.

The build platform is then incrementally lowered, allowing a new layer of liquid resin to flow over the cured layer. UV light is projected again to cure the new layer onto the previous one. This process of layer-by-layer curing and platform movement is repeated until the entire object is built.

Once the printing is complete, the object is typically still surrounded by uncured resin. It needs to be carefully removed from the build platform and to undergo post-processing steps, which may include rinsing, further curing under UV light as well as sanding, polishing or painting, depending on the desired finish.

Core Components of a DLP 3D Printer

• Build Platform: Supports the object during printing.
• Resin Vat: Contains the photopolymer resin.
• Light Source: Determines curing speed and print quality.
• DLP Projector: Controls the projection of UV light.
• Slicing Software: Converts 3D models into printable layers.

DLP 3D printing applications

DLP 3D printing is commonly used in industries such as jewellery, dentistry and medical devices, where precise and detailed prototypes are crucial for testing and validation. Similarly, digital light processing 3D printing plays a crucial role in the healthcare industry. While DLP excels in high-precision applications, other 3D printing technologies, like 3D printing in construction, enable large-scale manufacturing for architectural and infrastructure projects.

DLP 3D printing in healthcare is used, for instance, where precise dental models of patients' teeth and gums for treatment planning, orthodontic appliances, crowns, bridges and other dental applications are needed. On top of that, hearing aids and even anatomical models for medical education and surgical planning can be created with DLP 3D printing due to its high accuracy and resolution.

Applications in Dentistry

• Custom Dental Models: Used for treatment planning, orthodontic aligners, crowns, and bridges.
• Surgical Guides: DLP allows for precise, patient-specific templates to assist in complex dental procedures.
• Temporary and Permanent Restorations: Biocompatible resins enable functional, aesthetic dental prosthetics.

Applications in Medical Devices

• Hearing Aids: Digital light processing 3D printing is widely used for custom-fit, ergonomic hearing aids, reducing production time.
• Anatomical Models: Highly detailed organ and tissue models aid in medical training and surgical simulations.
• Medical Implants and Prosthetics: DLP printing supports customized prosthetics with biocompatible materials.

DLP 3D printing is revolutionizing jewelry design by allowing high-resolution, intricate detailing that was previously impossible with traditional handcrafting techniques. Designers can create complex patterns, filigree work, and organic shapes with unparalleled precision, significantly reducing the time and cost associated with mold-making.

Key Advantages for Jewelry Designers:

• Ultra-Fine Details: Enables micro-level precision for delicate designs.
• Castable Resins: Allows for direct investment casting, eliminating the need for traditional wax modeling.
• Custom and One-Off Pieces: Perfect for bespoke jewelry and rapid iterations before finalizing a design.
• Time Efficiency: Shortens prototyping cycles, allowing for quick market testing.

Digital light processing 3D printing has become a cornerstone technology in engineering and manufacturing, offering a rapid, cost-effective alternative to traditional prototyping methods. Its ability to quickly iterate designs and produce functional prototypes with high accuracy makes it an essential tool for automotive, aerospace, and industrial production.

Common applications are:

• Automotive Industry: Prototyping engine components, interior parts, and aerodynamics testing models.
• Aerospace and Defense: Manufacturing lightweight, high-strength parts for aircraft and drones.
• Consumer Electronics: Developing ergonomic and functional prototypes before mass production.
• Tooling and Molds: Creating high-precision molds for injection molding and small-batch production.

DLP 3D printing is paving the way for major advancements in medical research, tissue engineering, and bioprinting. Its ability to reproduce highly detailed anatomical structures makes it an invaluable tool for surgical planning, medical training, and the development of biocompatible implants.

Innovations in Bioprinting and Medical Research:

• Surgical Models: Doctors and medical students use 3D-printed organ models for pre-surgical planning.

• Bone and Cartilage Printing: DLP technology aids in custom prosthetics and regenerative medicine research.
• Drug Testing and Personalized Medicine: Researchers create miniaturized tissue structures to study disease behavior and test new drugs.
• Dental and Orthodontic Applications: DLP printing enables the production of clear aligners, crowns, and prosthetic components with biocompatible resins.

Even though DLP 3D printing has a lot of similarities with SLA (Stereolithography) 3D printing, there are still major differences between the processes, which result in different applications that serve different requirements.

DLP 3D printing uses a digital light projector to project an entire layer of the object onto the surface of a vat, solidifying the liquid photopolymer resin according to the shape of the object. As each layer is cured, the build platform gradually moves upward, distancing the solidified layers from the resin vat.

On the other hand, SLA 3D printing employs a laser beam that moves across the surface of a vat filled with liquid photopolymer resin. For even finer precision and detailed microstructures, microstereolithography (MSL) offers enhanced capabilities.

The laser selectively cures specific points in the liquid resin, causing it to solidify at those points. As each layer is scanned and cured, the build platform also gradually moves upward to create the object layer by layer.

As a result of these processes, DLP printing is usually faster due to its ability to cure entire layers at once, whereas SLA cures point by point with a laser, making it generally slower. SLA prints often have a smoother surface finish, while DLP prints can be slightly more textured.

Some 3D printing resins formulated for SLA might not work optimally in DLP printers and vice versa, so it's important to choose the appropriate resin for your printer.