The use of 3D printing to introduce students to ASTM standards for testing tensile properties of acrylonitrile-butadiene-styrene (ABS) plastic material

Abstract

In a freshman introductory plastics course at a mid-western state university and a technical college, students were introduced to several metal and plastic materials properties and were taught how some of these properties could be determined using testing procedures described in the American Society for Testing and Materials (ASTM) standards. One such standard is designated D-638-14, titled "Standard Test Method for Tensile Properties of Plastics," which states that "test specimens shall be prepared by machining operations, or die cutting, from materials in sheet, plate, slab, or similar form. Specimens can also be prepared by molding the material to be tested." Missing from the list of test specimen preparation methods are 3D-priting techniques. In this study, students prepared test specimens of Acrylonitrile-Butadiene-Styrene (ABS) plastic material by 3D-printing according to ASTM D638 Type 1 specimen specifications. These test specimens were compared to specimens prepared from ABS sheets by laser cutting to determine if 3D printing had a significant effect on the tensile properties of ABS test specimens. The test specimens prepared by laser cutting served as the control test specimens; this option replaced the use of injection molded specimens as the control test specimens because of the higher costs of the latter specimens. The fused-deposition-modeling 3D-printing machines used in this study were Makerbot" Replicator 2x, Lulzbot" TAZ 5, and Stratasys' Dimensions". The Instron materials testing machine, model 5967, was used in testing the tensile properties of the ABS specimens. The objectives of this study were