Using FEP Films in Resin 3D Printers

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Resin printing is an extremely valuable form of stereolithographic additive manufacturing (AM) which is used to rapidly generate intricate three-dimensional (3D) parts. It is one of the most popular 3D printing processes and is based on the most well-established AM principles to date.

 This article aims to explore the role of fluorinated ethylene propylene (FEP) films in resin 3D printers. First, we will discuss the basic configuration of typical resin printers before moving on to the material properties that make FEP films so uniquely suited to separating the UV light source from the photopolymer resin and build plate.

FEP Films to UV Lasers: The Basic Components of Resin Printers

Traditional resin printers, sometimes referred to as 3D SLA printers, are comprised of four chief components: A vat filled with liquid photopolymer; a moveable build platform within the vat that is driven by an elevator; a UV laser source used to cure the resin layer-by-layer; and a computer interface that controls the build platform according to associated CAD files. 

The configuration of different resin 3D printers varies, but FEP films are often used at the base of relatively small volume vats for compact systems. Sophisticated optics direct laser light upwards through the film causing the resin to selectively harden against the build platform. This is gradually raised as the printer progresses through the three dimensional design slice-by-slice. The XY resolution of resin printers refers to its lateral precision while the Z-axis determines individual layer height.

 As 3D printing has progressed, the development of DLP (Digital Light Processing) and LCD (Liquid Crystal Display) allows a whole layer of directional light across the surface of the resin at once.  This has proven to create much quicker builds, whilst the LCD light is also within the daylight wavelength range reducing overall light source cost.  These latter screens can be 4K creating high resolution printing on much larger vats.

Key Properties of FEP Films in 3D Printing

Transparency—specifically UV-transmissivity—is a crucial property for vat films used in traditional resin printers. Attenuation of UV waves would directly translate to reduced efficiency and can contribute to print failure. Additionally, materials at the base of print vats are routinely exposed to liquid photopolymers as well as physical wear-and-tear from regular contact with the polymer under increasing tension. It is therefore vital that FEP films exhibit exceptional chemical and tear resistance, whilst also enabling easy removal of excess resin after builds through low film surface energy. 

Interested in General Purpose FEP films?

At Saint-Gobain Films, we specialise in the generation of high-performance FEP films that are UV-stable with excellent chemical resistance even in harsh operating environments. Benefits include:

• Outstanding anti-stick release properties
• Optically transparent 
• Performance from -254°C (-425°F) to 205°C (400°F)
• Exceptional chemical resistance
• Product thickness from 0.0005" (0.013 mm) to 0.020" (0.76 mm)
• Widths up to 62" (1,575 mm) for 0.0005" to 0.010" and up to 48" for over 0.010" thick

We offer four distinct lines of FEP films under the CHEMFILM® brand, from general-purpose solutions to high molecular weight films. Contact us today if you would like to learn more about our product range.