How to Compare RP Materials to Production Manufacturing Materials

As RP materials continue to evolve, it is becoming necessary to be able to compare the performance of RP materials against the performance of production plastics that are common in manufacturing. In many cases, the design goal is no longer to use prototypes to prove a concept, but to verify design decisions based on how well a prototype performs in a test environment.

RP manufacturers use words like as mimics or simulates to describe how RP materials behave to help designers select that the material that most closely resembles the final production plastic to build a prototype. The challenge, however, is that UV-curable stereolithography (SL) resins have fundamentally different chemistries than injection-molded plastics-and many of the material properties are intrinsically different. Furthermore, huge variations exist among different production materials (one popular database contains more than 52,000 product data sheets). Given these difficulties, is there a reliable method to compare RP materials to production plastics-and if so, what is it?

A director of a medical equipment manufacturer's RP shop explains a simple but highly effective method that the company has developed for its internal use. After physically testing all its RP materials, the company developed a database of the stress/strain data for each material. The company also subscribes to an online material properties database (see Sampling sidebar) that includes the stress/strain data for more than 52,000 commercial plastics. By superimposing the stress/strain data for the RP material proposed over the stress/strain data for the production materials that the customer will be using, it is possible to select the best RP material for the customer's application.

For more information contact Charles Kaufmann of DSM Somos at (302) 326-8103.