Why Stereolithography?

One of the most widely used of all additive manufacturing technologies, stereolithography (SL) converts three dimensional CAD data to solid objects by curing thin cross-sections of specially formulated photopolymers with a finely focused laser. Excellent surface aesthetics are achieved with a degree of accuracy and precision that is among the best of all 3D printing technologies.

The SL process as originally commercialized for “industrial” applications and represented in UnionTech™ stereolithography 3D printers utilizes a build platform that is immersed in a vat of photopolymer creating a layer of polymer formulation ranging from 0.002 in. to 0.010in. A 355 nanometer wavelength laser draws the cross-section of the prescribed layer with instantaneous curing of the photopolymer. The platform then lowers to the desired layer thickness and a recoater passes over the platform to ensure a uniform layer of photopolymer for the next cross-section.

dental 3D printingDental 3D printed white

In recent years, a variety of equipment have been introduced under the stereolithography nomenclature that differ significantly in type and wavelength of the light source, recoating and material types utilized.

The use of the term stereolithography relative to UnionTech™ will be specific to the “industrial” SL process.

Shopping for parts or equipment, Why Choose Stereolithography?

Additive manufacturing (AM) process can be sorted by the material technology utilized which is either thermosetting or thermoplastic. Stereolithography utilizes thermosetting chemistry which involves forming an irreversible chemical bond upon curing. As an SL material is cured, the formulation components are combined to create the final material properties.


Thermoplastics, as the name implies, are used in processes that utilizes a melt mechanism to allow the plastic to be formed into specific shapes. The differences in material technology affect additive manufactured part characteristics of the various AM technologies relative to a variety of characteristics including part aesthetics such as surface smoothness, level and consistency of mechanical and physical properties. Notably, there are Pros and Cons to each commercial AM process.

Stereolithography …..it’s not just for prototyping anymore

The accuracy, precision , smooth surface and full density of SL produced parts , consistency of properties across all axis, and the ability to access one of the widest ranges of material properties of any AM process has made SL the most widely used AM process for concept models, form and fit and other prototype parts. These same characteristics have led to the expansive use of stereolithography for tooling and patterns: investment casting, RTV tooling (also known as urethane molding), thermoforming and injection molding. In fact, a substantially greater percentage of all photopolymer materials sold for SL are used for tooling and patterns than any other application.

Specialty photopolymers for SL have made large advancements in recent year resulting in a range of materials that offer high durability, long term stability over time, a wide range of clarity, color , and  mechanical properties. While earlier generations of SL materials lacked durability and mechanical properties required for functional testing compared to thermoplastic materials, current materials have now exhibit a significant area of performance overlap. These performance capability increases, coupled with the precision, accuracy and surface aesthetics of the SL process, create a much wider application capability for SL

UnionTech™ equipment is compatible with any photopolymer specifically designed for SL processing. Machine parameters can be adjusted to the degree decided by the equipment owner. Platform sizes vary from 10 square inches to approximately 32 square inches (model dependent), facilitating production of larges parts or multiple smaller parts. These freedoms in design create an open path for innovation and collaboration whether you are considering a prototype, indirect or direct manufacturing option.

Printer-Stereolithography USA

 Introducing a New Dimension in Stereolithography 3D Printing

• Cost effective ownership throughout entire life cycle

• Freedom to collaborate and innovate: open design for materials and machine access

• Surface aesthetics that reset expectations and contribute to lower post finishing requirements

Recognizing that experienced, local sales and service are critical components for delivering the full benefit of the UnionTech product line, RP Sales America, Inc has been named as the exclusive distributor for the USA.