Rapid Continuous 3D Printing via Orthogonal Dual-Color Photoinitiation and Photoinhibition.

Area of Science:

• Additive Manufacturing
• Polymer Science
• Optical Engineering

Background:

• Stereolithography (SLA) has evolved significantly, from early scanning methods to advanced volumetric printing.
• Rapid prototyping remains a key objective for researchers in additive manufacturing.
• Existing SLA techniques face limitations in printing speed and efficiency.

Purpose of the Study:

• To propose and demonstrate a continuous 3D printing system for enhanced speed.
• To leverage dual-color photoinitiation and photoinhibition for faster fabrication.
• To investigate the impact of an anti-polymerization layer on printing performance.

Main Methods:

• Developed a continuous 3D printing system utilizing ultraviolet (UV) light (355 nm) and blue light (470 nm).
• Employed dynamic masking and an anti-polymerization layer to control curing.
• Adjusted the intensity ratio of UV and blue light to control the inhibition zone.
• Utilized flow-structure interaction simulations to analyze the printing process.
• Conducted experiments on printing two different 3D structures.

Main Results:

• An intensity ratio of 28.6 achieved 97.1% inhibition volume for a 1 mm anti-polymerization layer.
• Increased anti-polymerization layer thickness improved resin filling rate and printing cross-sectional area.
• Reduced stress in the cured part was observed with thicker anti-polymerization layers.
• Achieved a printing speed of 200 μm/s with minimal impact on filling rate and stress at large thicknesses.

Conclusions:

• The proposed continuous 3D printing system significantly enhances fabrication speed.
• The dual-color photoinitiation/photoinhibition approach effectively controls the printing process.
• Further improvements in system design and resin formulation can increase printing volume and complexity.