Mechanical Engineering Commons^™

The Effect Of Heat On Fingertip Sensitivity Of Meat Processing Workers, Brian James Finder

Dissertations and Theses @ UNI

Current research indicates that acute non-freezing cold exposure elicits short-term performance problems; namely reduced upper extremity temperature, blood flow, tactile sensitivity, and dexterity. However, various animal-related studies indicate that humans are at increased risk of incurring semi-permanent upper extremity nervous system dysfunction as a result of repeated cold exposure.

The purpose of this research was to examine various factors that may contribute to hand/arm nervous system impairment of individuals who work in a refrigerated meat-processing environment. The methodology used was primarily the Experimental Method and from studies conducted by other researchers, was driven by the following questions:

(1) How would …

Simtrainer: A Management Training Tool, Wade Stark, Sema E. Alptekin

Industrial and Manufacturing Engineering

Abstract published of poster paper presented at conference.

Scheduling Semiconductor Device Test Operations On Multihead Testers, Tali Freed, Robert C. Leachman

Industrial and Manufacturing Engineering

Past attempts to devise scheduling methods for the device test operations of semiconductor manufacturing firms fail to address a significant characteristic of multiple-head test systems—the dependency of processing rates on the lots processed simultaneously on the testers. Since the problem has never been modeled accurately in the scheduling literature, feasibility and performance of previously proposed scheduling methodologies for multihead testers may not be accurately assessed. In this paper, we describe the multihead tester scheduling problem, present an enumeration solution procedure, and illustrate the problems of previously suggested tester scheduling algorithms.

An Evaluation Of Ploughing Models For Orthogonal Machining, Daniel J. Waldorf, Richard E. Devor, Shiv G. Kapoor

Industrial and Manufacturing Engineering

An analytical comparison is made between two basic models of the flow of workpiece material around the edge of an orthogonal cutting tool during steady-state metal removal. Each has been the basis for assumptions in previous studies which attempt to model the machining process, but no direct comparison had been made to determine which, if either, is an appropriate model. One model assumes that a separation point exists on the rounded cutting edge while the other includes a stable build-up adhered to the edge and assumes a separation point at the outer extreme of the build-up. Theories of elastic-plastic deformation …

Gauge Repeatability & Reproducibility Study For A 3-D Solder Paste Inspection System, Jianbiao Pan, Gregory L. Tonkay, Robert H. Storer, Ronald M. Sallade, David J. Leandri

Industrial and Manufacturing Engineering

Due to the increased use of Ball Grid Arrays (BGAs) and fine pitch and ultra fine pitch Quad Flat Packages (QFPs), there is a dramatic increase in demand for solder paste inspection after the stencil printing process. The important response variables of the printing process are deposited solder paste volume, area, height and position. To identify and remove defects at the earliest possible process step, a 3-D solder paste inspection system should be used to monitor solder paste deposited on all pads on every board before component placement. An example is a fully automatic laser-based 3-D triangulation solder paste inspection …

Critical Variables Of Solder Paste Stencil Printing For Micro-Bga And Fine Pitch Qfp, Jianbiao Pan, Gregory L. Tonkay, Robert H. Storer, Ronald M. Sallade, David J. Leandri

Industrial and Manufacturing Engineering

Stencil printing continues to be the dominant method of solder deposition in high volume surface mount assembly. Control of the amount of solder paste deposited is critical for fine pitch and ultra-fine pitch SMT assembly. The process is still not well understood as indicated by the fact that industry reports 52-71% of SMT defects are related to the solder paste stencil printing process. The purpose of this paper is to identify the critical variables that influence the deposited solder paste volume, area, and height. An experiment was conducted to investigate the effects of relevant process parameters on the amount of …

The Mechtech Program: An Education And Training Model For The Next Century, Robert Forrant

New England Journal of Public Policy

The small-firm metalworking industry is routinely characterized by cutthroat competition and fierce privacy. Yet, since the late 1980s, the members of the western Massachusetts chapter of the National Tooling and Machining Association have participated in an education, training, and technology diffusion network characterized by a high degree of interfirm cooperation. Hundreds of workers and managers have take part in group training sessions and seminars. The reconstruction of the skill base is central to the MechTech apprenticeship program through which apprentices spend four years in participating firms, exiting the program as licensed machinists, tool and die makers, or moldmakers. In an …

Screen Printing Process Design Of Experiments For Fine Line Printing Of Thick Film Ceramic Substrates, Jianbiao Pan, Gregory L. Tonkay, Alejandro Quintero

Industrial and Manufacturing Engineering

Screen printing has been the dominant method of thick film deposition because of its low cost. Many experiments in industry have been done and many models of the printing process have been developed since the 1960's. With a growing need for denser packaging and a drive for higher pin count, screen printing has been refined to yield high resolution prints. However, fine line printing is still considered by industry to be difficult. In order to yield high resolution prints with high first pass yields and manufacturing throughput, the printing process must be controlled stringently.

This paper focuses on investigating the …

Interventions Of Water Jet Technology On Skin Surgery, Kittipat Vichyavichien

Theses

The perfect and precise surgical cut, similar to today's laser one, is very important in many surgeries, especially in dissection and to recanaize arterial occlusive lessions. Causing no coagulation is one of the advantages of water jet because it generates no heat. It also provides omni-directional cutting capabilities at very high speeds, resulting edge quality that is usually superior to other existing conventional cutting processes. Debris is always carried away from incisions by jet stream and less damaged tissue, than mechanical incisions. In addition, water jet exerts minimal contact pressure on the tissue being cut due to the small diameter …

An Experimental And Analytical Study Of Ice Part Fabrication With Rapid Freeze Prototyping, Wei Zhang, Ming-Chuan Leu, Guanghua Sui, Zhiming Ji

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Rapid Freeze Prototyping (RFP) is a new solid freeform fabrication process that builds an ice part by rapidly freezing water layer by layer. In this paper, we will present our recent progress in the development of this novel process. An experimental system has been built for conducting the research. It consists of an XY-table and Z-stroke driven by micro-stepping motors and a water dispensing and deposition subsystem which incorporates a solenoid valve and a syringe pump placed inside a freezer. Simple heat transfer analysis is made to help select proper values of process parameters and predict part building failures. Example …

Assessment Of Environmental Performance Of Rapid Prototyping And Rapid Tooling Processes, Yanchun Luo, Ming-Chuan Leu, Zhiming Ji

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A method for assessing the environmental performance of solid freeform fabrication (SFF) based rapid prototyping and rapid tooling processes is presented in this paper. In this method of assessment, each process is divided into a number of life stages. The environmental effect of each process stage is analyzed and evaluated based on an environmental index utilizing the Eco-indicators that were compiled by PreConsultants of the Netherlands. The effects of various life stages are then combined to obtain the environmental performance of a process. In the assessment of SFF processes, we consider the material use in the fabrication of a part, …

Rapid Tooling By Integrating Electroforming And Solid Freeform Fabrication Techniques, Bo Yang, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper describes a rapid tooling process that integrates solid freeform fabrication (SFF) with electroforming to produce metal tools including molds, dies, and electrical discharge machining (EDM) electrodes. Based on experimental data analysis, the geometry and material of the SFF part, the properties of the electroformed metal, and the process parameters are significant factors that cause inaccuracy in the manufactured tools. Thermomechanical modeling and numerical simulation is used to determine the geometry of the SFF part and the electroform thickness for minimizing the manufacturing time and cost while satisfying the tooling accuracy requirement.

Industrial Engineering Made Simple, Deena Daggett, Sema E. Alptekin

Industrial and Manufacturing Engineering

Many high school students these days do not quickly recognize or identify Industrial Engineering (IE) procedures, practices, and products. Recruitment of qualified students into IE programs requires continuous planning, publicizing, and networking. Traditional recruitment efforts have included high school visits, brochures & flyers, and university-sponsored workshops. However, these techniques have only achieved mediocre success. Currently, a need exists for new promotional materials that utilize visual tools and provide a “hands-on” approach. We have developed several exercises that successfully introduce IE. Two such exercises are explained in this paper. The first exercise demonstrates the differences between Assembly line and Cellular Manufacturing …

On-Line Free Form Surface Measurement Via A Fuzzy-Logic Controlled Scanning Probe, Ming Chang, Paul P. Lin

Mechanical Engineering Faculty Publications

This paper presents a system and methodology for on-line free form surface measurement via a scanning contact probe installed on a CNC (computer numerical control) machine. The scanning probe provides more sampling points than any traditional touch trigger type of probes used on CNC machines, and better measuring accuracy than laser displacement sensing or structured lighting. The presented measuring system's main advantage is that the number of measured points can vary with the change of surface curvature. To improve the measuring stability and continuity, fuzzy logic control, in lieu of traditional PID control, is employed. As a result, the …

Relationship Between Cost Of Technical Training And Cost Reduction Of Internal Defects At John Deere Waterloo Foundry, John Brackin

Graduate Research Papers

Can the cost of technical training at John Deere Waterloo Foundry pay for itself in the reduction of internal defects? This research compared training costs to the savings from reduced internal defects on Molding Unit 801 located in the John Deere Waterloo Foundry. Training was the independent variable of this research. The results of this research identified a correlation between training costs ( operational definition on page 10) and defect reduction costs. A correlation between these two established a break even point for training dollars spent.

The dependent variable was the dollar savings based on reduction of internal defects. There …

Worn Tool Forces Based On Ploughing Stresses, Daniel Waldorf, Shiv G. Kapoor, Richard E. Devor

Industrial and Manufacturing Engineering

Recent work in modeling of the ploughing mechanism in basic metal machining may provide a means of estimating the additional forces to be expected when cutting with a worn tool. The results predict the rubbing stresses due to the finite radius of an unworn tool edge. Since an unworn tool can be thought of as a worn tool with a wear land width VB = 0, these stresses can make up part of a strategy for predicting the additional forces incurred by a worn tool. This paper develops a wear model by proposing a technique for utilizing the stresses predicted …

An Introduction To Web-Based Training For Statistical Process Control (Spc), Richard A. Juel

Graduate Research Papers

John Deere Waterloo Works had been using statistical process control in its manufacturing and assembly operations since the mid-nineteen seventies. Over the years this process had evolved from using hand-written paper control charts to using computer devices to collect data and generate charts. A variety of computer hardware and software products were being used. Training on statistical concepts and use of the various devices had deteriorated to the point that it was no longer a formal process. SPC training passed from one employee to another in the course of break-in to perform a specific job.

A team had been formed …

Screen Printing Process Design Of Experiments For Fine Line Printing Of Thick Film Ceramic Substrates, Jianbiao Pan, Gregory L. Tonkay, Alejandro Quintero

Industrial and Manufacturing Engineering

Screen printing has been the dominant method of thick film deposition because of its low cost. Many experiments in industry have been done and many models of the printing process have been developed since the 1960’s. With a growing need for denser packaging and a drive for higher pin count, screen printing has been refined to yield high resolution prints. However, fine line printing is still considered by industry to be difficult. In order to yield high resolution prints with high first pass yields and manufacturing throughput, the printing process must be controlled stringently.

This paper focuses on investigating the …

A Slip-Line Field For Ploughing During Orthogonal Cutting, Daniel J. Waldorf, Richard E. Devor, Shiv. G. Kapoor

Industrial and Manufacturing Engineering

Under normal machining conditions, the cutting forces are primarily due to the bulk shearing of the workpiece material in a narrow zone called the shear zone. However, under finishing conditions, when the uncut chip thickness is of the order of the cutting edge radius, a ploughing component of the forces becomes significant as compared to the shear forces. Predicting forces under these conditions requires an estimate of ploughing. A slip-line field is developed to model the ploughing components of the cutting force. The field is based on other slip-line fields developed for a rigid wedge sliding on a half-space and …

Fuzzy Logic Control Of A Model Airplane, Jon C. Ervin, Sema E. Alptekin

Industrial and Manufacturing Engineering

Common uses of fuzzy logic control today are found in relatively simple applications in products. These applications only scratch the surface of the potential of fuzzy logic control in complex mechatronic systems. In order to demonstrate the utility of fuzzy logic in complex device control, a fuzzy logic fly-by-wire system has been developed for a model airplane. The model airplane is a complex system of several critical inputs that require rapid processing and action in order to maintain flight stability. In addition, payload and power constraints severely limit the size, weight and processing power of the hardware to be carried …

Investigation Of Torque Control Systems For Pump Assembly, Donald E. Lynch

Graduate Research Papers

The purpose of the study was to determine which of three types of torque systems would best meet the torque specifications required in the assembly of hydraulic pump outlet valve plugs. Each torque system was evaluated in regards to expense, reliability, and effectiveness.

An Evaluation Of John Deere Waterloo Works Internal Quality System Audit Process With Recommendations For Improving Its Effectiveness, Karl J. Bultsma Sr.

Graduate Research Papers

The objective of this paper is to evaluate the internal quality system audit process at the John Deere Waterloo Works. This evaluation is necessary to identify improvements to ensure continued quality system registration and make the auditing process as efficient and effective as possible for improved business performance.

Tools For The Design Of Flexible Manufacturind Systems, Prashant A. Patel

Theses

Flexibility in manufacturing systems can broaden the horizons for a company. But the means for achieving it are far more critical. This trend is created by the increase in competitiveness, growth of technology along with demand variations, more customization, and short product life cycles. But "Flexible Manufacturing Systems" to most of the manufacturers sounds like a synonym for automation.

A real Flexible Manufacturing System is designed when every unit of the company is synchronized in such a way to respond in a harmony to any changes that come against it. Fine-tuning of each and every part of the company is …

Shell Cracking In Investment Casting With Laser Stereolithography Patterns, W. L. Yao, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper presents an investigation of ceramic shell cracking during the burnout process in investment casting with internally webbed laser stereolithography patterns. We hypothesize that shell cracking will occur when the rupture temperature of the ceramic shell is lower than both the glass transition temperature of the pattern material and the web· link buckling temperature. The hypothesis is validated by our experimental observations which confirm the numerical predictions from our finite element analysis. This provides a basis for design of the internal web geometry of a lithography pattern and evaluation of the burnout process with such a pattern. We show …

Rapid Freezing Prototyping With Water, Wei Zhang, Ming-Chuan Leu, Zhiming Ji, Yongnian Yan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Rapid Freezing Prototyping (RFP) with water is a novel solid freeform fabrication technique that can generate three-dimensional ice objects by depositing and rapidly freezing water layer by layer. The support where necessary is made of brine whose. freezing point is lower than. pure water. After building the part, the support can be removed by utilizing the melting temperature difference between brine and water. Preliminary experiments have shown that the ice patterns produced by this technique can be used for design visualization and silicone molding. This paper will present the concept and some experimental results of the RFP process as well …

Design Of An Effective And Timely Product Development Process For Medical Devices, Jean Benoit Almonor

Theses

Effective product development process is one of the most critical issues facing medical devices manufacturing today. There is a need to search for ways to improve or solve the cross organization and company boundaries to enhance the faster release of new medical products to the market. This thesis presents an integrated set of perspectives on the process of new product development of medical devices with dual goals of achieving marketing speed and meet customer satisfaction.

The Attribute Driven Specifications approach described in this thesis, is one of the most valuable tools in the approach to effective product development in medical …

Demanufacturing Metrics For Industrial Fasteners And Disassembly Process, Narendra P. Raj

Theses

As the society progresses towards ecological maturity, the issue of reducing the environmental burden imposed by used products becomes increasingly important Environmental issues are becoming increasingly relevant for product designers and manufacturers. Public awareness of the value and fragility of an intact ecology is constantly growing, and the traditional assumption that the cost of ecological burdens to be shared by a society, as a whole is no longer accepted. Environmental protection legislation requiring manufacturers to "take back" and recycle used products will be a commonplace throughout Europe and the U.S. in the near future.

Demanufacturing involves separating and disassembling a …

Degree Of Manufacturer Readiness For Skill-Based Pay Programs, Michael R. Willett

Graduate Research Papers

The purpose of this study is to determine the degree of readiness of manufacturing companies in Black Hawk County, Iowa, to adopt a skill-based pay plan. Readiness, or change orientation, will be determined by comparing current characteristics of companies in this sample to those characteristics of American companies that have already implemented successful skill-based pay plans.

An Evaluation Of The Aws Entry Level Welder Training Program, John R. Rice

Dissertations and Theses @ UNI

The purpose of this study was to evaluate the effectiveness of a training program for Entry Level Welders and to provide this information to the American Welding Society (AWS), industry, and educators. The problem of this study was to evaluate the AWS Entry Level Welder Training Program (ELWTP) by obtaining the opinions of faculty members who taught the program and welders who had completed the program.

Two groups comprised the research population for this study. The first group consisted of faculty members who were actually involved in teaching the course at institutions accredited by the AWS to offer the curriculum. …

Multi-Lifecycle Assessment Of Cathode Ray Tubes, Devendra Jayant Badwe

Theses

Over the past few years environmental issues and concerns have become more and more important, as they become a common part of most people's personal experience. In these regards, the electronics industry is facing substantial problems in terms of end-of-life management of its products, televisions and monitors in particular. The building blocks of this industry are usually viewed as relatively "clean". However, manufacturing by-products of the electronics industry and the disposition of electronics are becoming increasingly important technical, financial, and environmental issues.

Within the context of the above issues, environmentally responsible disposal of Cathode Ray Tubes (CRT's), which is still …