Composite rapid prototyping: overcoming the drawback of poor mechanical properties

Stereolithography and vacuum casting are two well-established techniques for producing complex parts for rapid prototyping purposes. Although they have been used across a wide range of industrial sectors, parts fabricated by those techniques exhibit weak mechanical properties hindering thus their further application as functional prototypes under loading conditions. This paper investigates the effects of the addition of nonwoven glass fibre mats, and of various thicknesses, on the mechanical properties of laser solidified and vacuum moulded specimens. The test specimens were fabricated using an epoxy-based photopolymer for the stereolithography and a polyurethane resin for the vacuum casting process, correspondingly. Embedment/bonding issues of the reinforcing mats are discussed, while comparisons of the mechanical properties between nonreinforced and their fibre mat reinforced counterparts are also presented. Experimental results show that fibre mat addition yields higher measured tensile properties, with the most pronounced improvements obtained for the reinforced polyurethane specimens.