VLM aims to overcome barriers to 3D printing

A 3D-printing system designed for the rapid production of high-performance parts at low cost has been developed by Barcelona-based BCN3D.

Three-years in development, Viscous Lithography Manufacturing (VLM) has been designed by BCN3D for manufacturers to overcome barriers to adopting 3D-printing such as accessibility, part performance and productivity.

Eric Pallarés, CTO at BCN3D, said 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 resins - up to 50 times more viscose than industry standards and three times more impact resistant - are mono-component formulations printed at room temperature.

High viscosity allows for chemical formulations that improve the performance of finished parts (Image: BCN3D)

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.

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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.

In a presentation, Dario Destro, BCN3D’s head of materials said: “VLM resins can include a high fraction of oligomers. 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.”

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Arkema has worked with BCN3D through a Joint Development Agreement (JDA) in which the two companies are co-developing new materials for VLM that obtain properties currently not possible with other resin-based 3D printing processes. BCN3D has also partnered with Prodrive, which has been assembling end-use parts made with VLM mounted directly on cross-country cars.

BCN3D 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.