Stereolithography, also known as Vat Polymerisation, employs a vat of photopolymer resin, which is selectively cured using Ultra Violet (UV) or Visible (Vis) light while a support platform moves the cured object downwards layer by layer. The process uses photo-polymer formulations comprising oligomers, monomers and photo-initiators that cross-link on exposure to UV or Visible light. The properties of the final cured material, such as its modulus and chemical properties are influenced by the molecular weight distribution and molecular structure of the oligomers, and ratio of photo-initiator. The rheology and viscosity of the photo-polymer formulation are also affected by these properties.
Malvern Panalytical techniques for use in this application include Gel Permeation Chromatography (GPC). GPC can be used to characterize the molecular weight and molecular structure of oligomers or polymers used in the process and can aid the development of new photo-polymer resins. It is also possible to follow the progression of light-initiated curing reactions in real time using a UV/Vis curing accessory.