FastPrinting

The field of 3D printing is a hot area and is actually claimed as a “revolution”. The aim of the present proposal is to develop, in collaboration with an industrial partner, new photosensitive resins specifically adapted for 3D printing. The present consortium (from both academia and industry) is based on internationally recognized groups for the different aspects of the project (synthesis of the photoinitiators PI, study of the chemical intermediates, polymerization, 3D printing …), who have joined in an effort to answer one of the societal challenges evidenced by the ANR (see below). This project is in perfect agreement with the present call "industrial revival" and still more particularly with the aspect "Matériaux et Procédés". Indeed, this project completely answers to the development of new tools and methods for the production or the study of new polymer products which can be conceived, prototyped and tested in short time and for a reduced cost. It also resorts to the section "Procédés économes et intensifiés" because of the potential use of low-energy photochemistry in polymer producing processes. In particular, the use of light emitting diodes (LEDs) to industry processes (such as 3D printing) offers tremendous potential to stimulate industrial renewal. For 3D printers using polymers through the stereolithography or the inkjet 3D printing, the writing speed is actually the strongest limitation and the increase of the resin sensitivity is actually the crucial challenge. The use of Light Emitting Diodes LED@405 nm as the irradiation device corresponds actually to the reference in this technology as LEDs are characterized by intrinsic advantages (low energy consumption, very compact, safer than laser …). However, the current commercial photosensitive resins are based on UV Type I photoinitiators that are perfectly adapted for the classical UV-curing field using Hg lamp but clearly not to the 3D-printing area using a LED with an irradiation wavelength at 405 nm. Therefore, these photoinitiators, not really adapted to the irradiation wavelengths of the LED used in 3D printers (405 nm), lead to slow printing speeds. In strong collaboration with an industrial partner (the SME: Photon & Polymers noted PnP), we will propose to drastically improve the photosensitivity of these resins through the development of new systems specifically adapted for this application. The great originality is the development of high performance photosensitive formulations, this will undoubtedly overcome this issue and constitute a breakthrough in the field of 3D LED printing. This project of how to improve the chemistry (e.g. the photosensitivity) of the resins for 3D printers will allow to the French academic and industrial community to play a key role in this emerging domain. The participation of an industrial partner with a strong background in this field is important for the success of the project but also offers a high potential of valorisation (a significant part of the PnP activity is already based on 3D printing but is expected to increase if new reactive resins are successfully developed). In the present project, we will develop new photosensitive formulations (photoinitiating systems and monomers/oligomers) well adapted for 3D LED printing requiring specific conditions (irradiation wavelengths, light intensity, viscosity, writing speed ...) since the current formulations are not so well adapted. An almost complete lack of really efficient initiating systems for 3D LED printing can be noted. For the first time, all the active component of the photosensitive resins will be developed for this specific application: both the initiating systems and the monomers/oligomers will be taken into account.