Direct UV Printing (DUP)

DUP 3D Printing Method

This 3D printing technology employs LCD Displays as a pixel matrix. LCD (= liquid crystal displays) influence under the application of voltage, liquid crystals and the according transmission of light. With the direct UV printing (DUP) method, UV-LEDs are used as background lighting, typically between 395 nm – 405 nm (UVA). Therefore, the DUP 3D printers use a fundamentally narrower UV spectrum as compared to DLP beamers.

Useful Resins for Direct UV Printing (DUP) 3D Printers

When using the narrower UV LED spectrum in printers, it’s important to consider which resin is a best fit to the printer and the needed requirements. Depending on how sensitive the resin is or which wave length intensity, the LED source exposure time determines directly the polymerization process or the curing of the resin.

Moreover, the distance between the display with the LED background lighting directly influences a projected surface such as a resin vat. DLP Processing distorts the distance between the projected picture and must be corrected. This is process of constantly correcting is omitted with the narrow intervals of the DUP method.

Wanhao D7, Anycubic Photon, Slash

Current 3D printers which use the DUP method are for example the printers from Wanhao D7, Anycubic Photon, Slash, Sparkmaker SLA, just to name a few. These printers are smaller size and the low cost compared to those of the DLP devices since the LCD displays are bulk commodity products along with the display screen control have long been adopted in other technology areas.  One disadvantage of the devices compared to DLP or SLA printers are the low light intensities, which means a longer exposure time. One resin which works both with DUP 3D printers and DLP devices is the Druckwege Typ D Resin.