VLM printing promises additive breakthrough

1 min read

A new method of 3D printing known as Viscous Lithography Manufacturing (VLM) is being hailed as a major step forward for rapid and low-cost additive manufacturing of high performance parts.

Developed by Barcelona-based BCN3D, VLM  is a resin-based technology that uses UV light and an LCD screen to photopolymerise high viscosity resins in a four-step lamination process. The additive process, which operates at room temperature, is capable of printing resins that are up to 50 times more viscous and three times more impact resistant than industry standards.

The resin is first picked up by a roller and laminated to the underside of a transparent film which is then transferred to the printing area. The build plate rises and comes into contact with the laminated resin at the desired layer thickness. UV light cures the resin in a specified area creating the new layer of the object to be printed. The build plate then retreats causing the cured later to peel away from the film while the unused resin is recovered and recirculated in the system’s reservoir.

VLM’s mechanical system also allows the resin to be laminated from both sides of the film, which can speed up printing times or allow combinations of different resins to make multi-material parts and manageable supports.

“VLM resins can include a high fraction of oligomers,”Dario Destro, BCN3D’s head of materials, said during a presentation on the new technology.

“When the light is shone a loosely cross-linked polymer network is obtained. This internal structure is capable of withstanding mechanical stresses in a flexible manner, behaving like industrial grade moulded elastomers such as vulcanized rubbers, silicones and polyurethanes. As a result, mechanical properties such as strength toughness and tear resistance are significantly improved. For this reason VLM resins aim to obtain 200 per cent increment in tear strength compared to current industrial standard formulations.”

BCN3D says it will offer its solution at a cost of under €50,000 and has set up a Technology Adoption Program for companies of any size wanting to utilise VLM.