Moneer Helu

Environmental analysis of milling machine tool use in various manufacturing environments

A life-cycle energy consumption analysis of a Bridgeport manual mill and a Mori Seiki DuraVertical 5060 has been conducted. The use phase incorporated three manufacturing environments: a community shop, a job shop, and a commercial facility. The CO2-equivalent emissions were presented per machined part. While the use phase comprised the majority of the overall emissions, the manufacturing phase emissions were significant especially for the job shop, which is not as efficient as the other facilities due to its inherent need for flexibility. Since the Mori Seiki is heavier, the manufacturing phase of this machine tool had a greater impact on emissions than the Bridgeport. Transportation was small relative to the use phase, which was dominated by cutting, HVAC, and lighting. These results highlight areas for energy reductions in machine tool design as well as the importance of facility type to the manufacture of any product.

Understanding error generation in fused deposition modeling

Additive manufacturing offers completely new possibilities for the manufacturing of parts. The advantages of flexibility and convenience of additive manufacturing have had a significant impact on many industries, and optimizing part quality is crucial for expanding its utilization. This research aims to determine the sources of imprecision in fused deposition modeling (FDM). Process errors in terms of surface quality, accuracy and precision are identified and quantified, and an error-budget approach is used to characterize errors of the machine tool. It was determined that accuracy and precision in the y direction (0.08–0.30 mm) are generally greater than in the x direction (0.12–0.62 mm) and the z direction (0.21–0.57 mm). Furthermore, accuracy and precision tend to decrease at increasing axis positions. The results of this work can be used to identify possible process improvements in the design and control of FDM technology.

Total Cost Analysis of Process Time Reduction as a Green Machining Strategy

Manufacturers have pursued green machining strategies, such as process time reduction, to address the demand for environmental impact reduction. These strategies, though, increase the stresses on the manufacturing system, which can affect availability, service life, achieved part quality, and cost. This study presents a total cost analysis of process time reduction for titanium machining to holistically consider the implications of such strategies. While the results suggest it may not be a viable green machining strategy for titanium machining, the feasibility of process time reduction as a greening solution is highly dependent on the functionality of the finished part.

Evaluating Trade-Offs Between Sustainability, Performance, and Cost of Green Machining Technologies

The growing demand to reduce environmental impacts has encouraged manufacturers to pursue various green manufacturing technologies and strategies. These solutions, though, may have a direct impact on several productivity metrics including availability, quality, service life, and cost. This study presents an approach to evaluate the trade-offs between the environmental, performance, and financial impacts of green machining technologies by combining green manufacturing principles into life cycle performance evaluation. The approach is validated by investigating the implications of reducing the processing time by increasing the cutting speed and chip load to green a horizontal milling process.

Enabling Technologies for Assuring Green Manufacturing

This chapter reviews various technologies applicable in characterizing the resource utilization of manufacturing processes. A review of sensors to measure and quantitatively characterize the various flows involved in manufacturing processes and machines is first presented. Given the complexity of managing and parsing the sensor data, software tools are needed to automate data monitoring and the chapter presents a framework based on event stream processing to temporally analyze the energy consumption and operational data of machine tools and other manufacturing equipment. Finally, a case study that focuses on energy measurements and demonstrates the use of energy monitoring in reasoning over the performance of a manufacturing system is presented.

Closed-Loop Production Systems

This chapter discusses the closed-loop aspects of production systems in the context of green and sustainable manufacturing. Specifically, we consider the life cycle of production systems from design and construction through use, decommissioning, and recycling or repurposing. We discuss resource and economic efficiency and present a series of examples of life cycle analysis of manufacturing systems. We also describe how to design systems for reduced life cycle impact. Examples include comparisons of different machine tool systems, process parameter optimization, consumable utilization, plant services, and plant design.

Principles of Green Manufacturing

The purpose of this chapter is to illuminate some of the basic principles of green manufacturing. That is, establish a framework of principles against which relevant examples can then be mapped to determine how green a system or solution is and find areas for potential improvements. This forms the structure of the discussion in following chapters where specific manufacturing processes or systems are investigated in more detail. We propose the following five principles: (1) a comprehensive systems approach must be used to evaluate and improve manufacturing processes from a green perspective, (2) the system should be wholly viewed across both the vertical and horizontal directions, (3) harmful inputs and outputs of the system to the environment and humans should be reduced or removed, (4) net resource use should be lowered, and (5) temporal effects on the system should always be considered. These are discussed in detail.

Design and Fabrication of a Roller Imprinting Device for Microfluidic Device Manufacturing

Microfluidic devices are gaining popularity in a variety of applications, ranging from molecular biology to bio-defense. However, the widespread adoption of this technology is constrained by the lack of efficient and cost-effective manufacturing processes. This paper focuses on the roller imprinting process, which is being developed to rapidly and inexpensively fabricate micro-fluidic devices. In this process, a cylindrical roll with raised features on its surface creates imprints by rolling over a fixed workpiece substrate and mechanically deforming it. Roller imprinting aims to replace processes that were developed for laboratory scale prototyping which tend to not be scalable and have high equipment requirements and overheads. We discuss the limitations of PDMS soft lithography in large-scale manufacture of microfluidic devices. We also discuss the design, fabrication, and testing of a simple roller imprinting device. This imprinter has been developed based on the principles of precision machine design and is implemented using a three-axis machine tool for actuation and position measurement. A framework for the micromachining of precision imprint rolls is also presented.