3D printing enables the production of lightweight yet strong and robust plastic parts. In addition to common processes such as FFF (fused filament fabrication) and SLA (stereolithography), the advanced DLP (digital light processing) process has been available for several years. With DLP technology, a liquid photopolymer that hardens when exposed to light is built up layer by layer to form a three-dimensional object. This method makes it possible to produce detailed and complex shapes with a high degree of accuracy. The main advantages of the DLP process are

• High level of detail due to the production of very thin layers
• Short production times thanks to the fast printing speed of complex parts
• Lower material costs due to efficient consumption and reduction of waste
• Simple handling of the process, without complicated setup or expert knowledge

For the DLP process, the manufacturer ETEC offers systems for individual and series production with a large selection of materials. ETEC is characterized by the high quality and reliability of its systems, which makes them easy to integrate into existing production processes.

With 3D scanning, surfaces and objects can be captured and converted into digital 3D models using a large number of data points. 3D scanning is used in various industries and offers the following possibilities:

• Quality assurance
• Component optimization
• Reverse engineering
• Product development
• Spare parts production

The manufacturer GOM Metrology, a subsidiary of Zeiss, presents the Gom Scan 1, a mobile and powerful 3D scanner. Thanks to the specially developed GOM Blue Light technology, precise scans and short measuring times can be achieved.

The manufacturing technology used by Boston Micro Fabrication (BMF) is based on projection micro-stereolithography

Basic principle

PµSL enables rapid photopolymerization of a layer of liquid polymer by means of UV projection. Similar to Digital Light Processing (DLP), the entire image or a defined section of it is cured in a single exposure step.

System structure

As a form of stereolithography, PµSL requires a digital light processing engine (DLP), precision optics, high-precision motion control and associated software. Between the UV light source and the resin tank is a high-precision lens that focuses the projected image to the micrometer range. Precision rails control the XYZ movements of the resin tank.

Process flow

The liquid photopolymer resin is contained in a resin tank. Layer after layer is built up from top to bottom: The DLP unit projects the cross-sectional image of the respective layer onto the resin surface, whereupon the resin cures this area using UV light. A plastic membrane stretches and levels the uncured resin in the tank to ensure a uniform layer thickness. The build platform then lowers by one layer thickness and the process repeats until the component is fully built up

Stereolithography (SLA) belongs to the vat photopolymerization (VPP) technology group. In this process, a liquid, light-sensitive binder is cured layer by layer using a UV laser.

After each layer, the build platform moves downward along the Z-axis by the thickness of that layer—typically between 25 and 125 µm. This is how the part is formed.

This is a so-called top-down technology, which has the advantage of requiring as few support structures as possible.