Search Results

1. Marks, Christopher Mold deflection and mold parting plane separation during the injection molding process /

Master of Science, The Ohio State University, 2005, Graduate School

Committee: Not Provided (Other) Subjects:

2. Meyer, David Industrial Plastics Technologist's Duties and Tasks to Meet Employer Needs in the Greater Dayton, Ohio Area

Doctor of Philosophy, The Ohio State University, 2008, ED Teaching and Learning (Columbus campus)

This descriptive survey research explores and identifies duties and tasks on the demand side of what industry needs in a plastics technologist. An occupational study was initiated with the endorsement of five professional organizations and covered 29 plastics manufacturers in the greater Dayton, Ohio area. The occupational analysis method called DACUM (Developing A Curriculum) was used to identify the duties and tasks and related core competencies. An expert panel for the DACUM process consisted of experienced practitioners working within the plastics manufacturing field. The expert panel identified, organized and verified the duties and tasks, which led to the DACUM Research Chart containing 11 duties, 78 tasks and 72 enablers. The DACUM Research Chart was used to develop a task verification survey instrument for plastics technologists and consisted of enablers, demographics from responders, processes used in manufacturing, and the three most important research questions. The questions are as follows: 1) Does an entry level plastics technologist PERFORM this task? 2) How IMPORTANT is this task in the performance of your job? and 3) How DIFFICULT is it to perform this task? The population of plastics companies in the Dayton, Ohio area was determined to be 29 and one task verification survey questionnaire per company was mailed to the qualifying and volunteer plastics technologists employed in the manufacturing of plastic products. The survey data collection period of 30 days yielded a response rate of 93 percent. The survey responses led to the following findings: (1) the DACUM process has resulted in information useful for plastics technology curriculum development for a two-year community college; (2) the differences in the tasks percentages and means were small indicating possible curriculum improvement for entry level, tasks importance to the job, and difficulty to perform job; (3) the respondents with post secondary degrees tended to rate certain tasks and enab (open full item for complete abstract)

Committee: Paul E. Post PhD (Advisor); Robert E. Norton PhD (Committee Member); Christopher J. Zirkle PhD (Committee Member) Subjects: Technology

3. Perry, William Plexiglas, a content study for industrial arts education /

Master of Arts, The Ohio State University, 1947, Graduate School

Committee: Not Provided (Other) Subjects:

4. Hertenstein, Kery The development of a polymer recycle system for a plasticating extruder /

Master of Science, The Ohio State University, 1971, Graduate School

Committee: Not Provided (Other) Subjects:

5. Castro, Carlos Optimization and analysis of variability in high precision injection molding /

Master of Science, The Ohio State University, 2005, Graduate School

Committee: Not Provided (Other) Subjects:

6. Gaido, Thania Evaluation of alternative injection strategies with variability consideration in injection molding /

Master of Science, The Ohio State University, 2007, Graduate School

Committee: Not Provided (Other) Subjects:

7. Jones, Billy Performance of Shallow Cover Thermoplastic Pipes Subject to Temperature Change and Live Load Cycles

Master of Science (MS), Ohio University, 2024, Civil Engineering (Engineering and Technology)

The production of newer, stronger plastic pipe profiles in recent decades has broadened their application range where concrete or steel materials once ruled. The cost advantages of thermoplastic pipes, due to lower installation and material costs, have seen their use increase in frequency. With increasing usage, concerns over the performance of these culverts have been expressed by various state Departments of Transportation, especially when subjecting plastic pipe profiles to increased temperatures. The purpose of this research is to assess the performance of five shallow cover thermoplastic pipes, during repeated load cycles, across a broad temperature range. Five thermoplastic pipes made of polypropylene or high-density polyethylene were buried and instrumented prior to being subject to 80,000 load cycles of an 11-kip dual tire load and sustained air temperatures between 35 to 102 degrees Fahrenheit. The pipe and soil embedment behavior were monitored frequently in the beginning of experiment, during significant temperature changes, and every 10,000 load cycles thereafter. Throughout testing pipes performed well and did not approach the failure criteria outlined by AASHTO LRFD or the manufacturer recommendations, despite not achieving the minimum cover requirement of 24 inches to the flexible pavement later. Results suggest that given proper installation, stout pipe profiles, and a thick asphalt layer; the current minimum cover requirements are not necessary to obtain adequate shallow cover pipe performance and prevent damage to an overlying asphalt layer.

Committee: Issam Khoury (Advisor); Paul King (Committee Member); Teruhisa Masada (Committee Member); Shad Sargand (Committee Member) Subjects: Civil Engineering

8. Smith, Travis Chain-level conceptual understanding of the deformation of semicrystalline polymers and the fracture of ductile glassy polymers

Doctor of Philosophy, University of Akron, 2023, Polymer Science

Polymeric materials possess many useful properties, especially low density and high toughness. When crystallized, solvent resistance and temperature resistance are imparted. Predrawing can enhance their mechanical strength and toughness. However, whereas semicrystalline polymers (SCPs) like polyethylene (PE) and polypropylene (PP) are ductile, poly(lactic acid) (PLA) and poly (hydroxyalkanoates) (PHA) often show brittle behavior. In the face of a worldwide push for sustainable materials, it has become necessary to uncover the molecular picture that governs the processing-structure-property (P-S-P) relationships regarding the ductility (or lack thereof) of polymers. One example is how various types of predeformation can affect the mechanical properties. It has been shown [1] that pre-melt stretching of PLA in the near-affine limit close to the glass transition temperature Tg was shown to greatly enhance the strength and ductility of otherwise brittle PLA, and to produce a nanoconfined (NC) crystalline state whose length scale is on the order of the mesh size of the deformed chain network. Furthermore, this melt stretched PLA contained significant crystallinity and was transparent. In Chapter I, we show that after pre-melt shearing of amorphous PLA above Tg, the resultant crystalline and transparent PLA remains brittle. Both atomic force microscopy imaging (AFM) and small-angle x-ray scattering (SAXS) verify that melt-shearing has also produced an NC crystalline state. However, the brittle behavior of the melt-sheared PLA demonstrates the importance of having geometric condensation from processing. A similar NC crystalline state was generated in melt-sheared PET, thereby demonstrating the apparent universality of the methodology. In Chapter II, the P-S-P relationships are explored for SCPs that are crystallized under quiescent conditions. Since a disproportionate extent of effort has gone into researching the mechanisms of yielding rather than the origins of brittl (open full item for complete abstract)

Committee: Shi-Qing Wang (Advisor); James Eagan (Committee Chair); Fardin Khabaz (Committee Member); Mesfin Tsige (Committee Member); Toshikazu Miyoshi (Committee Member) Subjects: Physics; Plastics