Author: David B. Helmick II
Source: This material is based upon work supported by the National Science Foundation under Grant No. EEC- 1542358.
Students are completing a comparative analysis to test the physical properties of a given material using two different devices: a 3D printer & transfer mold machine. In technical terms: students using an extruder will make their own filaments and 3D print Izod Impact Resistance Bars and Tensile Bars to test the material & production-process strength against the same material/shaped bar for Izod & Tensile Bars made using a transfer mold machine. Students will complete a comparative analysis of two tests: Izod Impact Resistance ASTM D-256 & Tensile Strength ASTM D-638M. (Again, optional 3-point bend test could be conducted in place of these two tests). Students will evaluate their data to provide a solution to a real-world problem in industry/society that they determine to answer. Students will need to conduct research to determine a real-world problem. Students’ data must be used to support their claim to their answer of the real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics as well as possible social, cultural, and environmental impacts.
*Note* This lesson is written for Engineering Students completing a Polymer Testing Course; but the research aspect can be adapted to fit the research/report needs of a chemistry or physics class with an optional modified 3-point bend testing version with different directionally printed 3-D samples in the worksheets section for those without the proper equipment.
What should students know as a result of this lesson?
Through completion of the comparative analysis students should:
What should the students be able to do as a result of this lesson?
Through completion of the comparative analysis students will be able to:
Engage students by demonstrating how to use the Izod Impact Tester and the Tensile Machine. Both are destructive tests and the students are fully engaged in destroying parts!
Assessment: Student completion of the safety test for using the machines and the accurate execution of using the machines. Students notes in their Engineering Notebooks on proper machine usage and safety procedures.
Students can explore on their own by conducting the ASTM tests for each machine and reporting their findings using the standardized report format.
Assessment: Students lab report with reported data collected from the testing machines
Students may need further explanation of the testing procedures or trouble shooting while performing the actual test. The instructor needs to be ready to provide just-in-time instruction to the students on an as needed basis for each machine. Only one student can be using a machine at a time, thus allowing the instructor to provide one-to-one instruction.
Verbal interaction between the instructor and student provides great formative assessment to help further instruction. Students final findings will be reported on their lab report, so before students data is collected incorrectly, misconceptions can be addressed and data collection corrected during this time. Students can use their Engineering Notebooks to record data and analyze the consistency of their results. If outliers are present they need to think about what errors they may have made and possible re-test to see if their findings are conclusive or not.
After learning how to use each of these machines to conduct tests on and report their findings, students will begin their comparative analysis of 3D printed vs Transfer Molded Parts. Students will be given the 3D Printed vs Transfer Molded Comparative Analysis Checklist & Rubric to begin their research (see attached rubric in Worksheets section). Students will work individually to research and select a real-world problem or issue in the field of polymer packaging or manufacturing. Students will select an associated material with this problem. Students will then devise their experiment and testing procedures to collect data to validate a conclusion to answer their identified problem based upon the conditions outline in the checklist & rubric.
This lesson is specifically written for second year students in a two-year career technical education Engineering Program. Students have background in using the associated machines to perform these tests with and some introductory knowledge of polymers. With frontloading and additional resources this lesson could be adapted to use with students that have zero background in polymers. The teacher would need to provide adequate readings or lessons to the students about polymers and their use in industry. Additionally the research aspect of this assignment could be made a group project so that the workload is divided up into content-specialist areas.
Engineering and Science Technologies and Manufacturing Technologies Career Field Teachnical Content Standards
ODE Table 2: Expectations for TECHNOLOGICAL AND ENGINEERING DESIGN GRADES 9-12
Engineering and Science Technologies and Manufacturing Technologies Career Field Technical Content Standards
Polymer Testing, Production Manufacturing, Packaging Industry, and any consumer product production industry.
3D Printing vs Transfer Molding Comparative Analysis Final Report.
A typed lab report following the rubric detailed in the Worksheets section.