Kenneth L. Gunter

An experimental investigation into the effect of process conditions on the mass concentration of cutting fluid mist in turning

Abstract Cutting fluid mists that are generated during machining processes represent a significant waste stream as well as a health hazard to humans. Epidemiological studies have shown a link between worker exposure to cutting fluid mist and an increase in respiratory ailments and several types of cancer, prompting closer scrutiny from several regulatory agencies. In this work, statistically designed experiments were conducted to determine the machining conditions that have the most significant effect on PM10 and PM2.5 mass concentration levels of cutting fluid mist during a turning operation. Identification of these significant factors may lead to modifications in the machining process as a solution for minimizing cutting fluid mist, thus eliminating/reducing the need for costly mist control technology such as air filters, enclosures, and fluid additives.

A GLOBAL PERSPECTIVE ON THE ENVIRONMENTAL CHALLENGES FACING THE AUTOMOTIVE INDUSTRY: STATE-OF-THE-ART AND DIRECTIONS FOR THE FUTURE

With support from the US National Science Foundation and Department of Energy, a global benchmarking study of the status of Environmentally Benign Manufacturing (EBM) has recently been completed. The study, completed under the aegis of the World Technology Evaluation Center at Loyola College in Maryland, gathered information on research and development around the world aimed at developing alternative methods for materials processing with the purpose of minimising toxic material generation and optimising products and by-products for sustainability and reuse characteristics. The study reviewed the current status of EBM research, development, and applications in the United States, Japan, and Europe with a view towards evaluating the competitive status of US efforts. Information was acquired from the technical literature as well as through visits to industry, national laboratories, universities, etc. One area of focus within the study was the automotive industry. This paper summarises many of the key findings from the global benchmarking study that relate to the automotive industry and identifies areas that require attention for the future. (A)

A model for material flows and economicexchanges within the U.S. automotive life cycle chain

Abstract A simulation model for material flows and economic exchangeswithin the U.S. automotive material life cycle chain is presented. The model is employed to examine the effect of future changes in vehicle material composition on the automotive recycling infrastructure.The model results indicate that as vehicle material composition changes, higher dismantling/recovery rates are needed to ensure economic viability of the recycling infrastructure. Furthermore, even in the case of significantly higher rates of dismantling and plastics recovery, the amount of shredder residue per vehicle will continue to rise.

A Model for Improving Economic Performance of a Demanufacturing System for Reduced Product End-of-Life Environmental Impact

Abstract A demanufacturing facility benefits the environment by removing end-of-life products from the disposal waste stream. The facility dismantles end-of-life products and then places salvaged components into inventory for subsequent sale to remanufacturers and other firms. Lack of profitability will cause a demanufacturing facility to abandon its mission, with the environment suffering as a result. A model is presented for a demanufacturing facility that describes the disassembly process activities, the accumulation of component inventories, component sale based on market price behavior, and inventory management costs. The effect of three selling policies on financial performance is investigated. Selling policy is seen to be the dominant factor in determining profitability, with transaction and holding costs also influencing the performance.

Character and Behavior of Mist Generated by Application of Cutting Fluid to a Rotating Cylindrical Workpiece, Part 1: Model Development

Increasing attention is being devoted to the airborne emissions resulting from a variety of manufacturing processes because of health, safety, and environmental concerns. In this two-part paper, a model is presented for the amount of cutting fluid mist produced by the interaction of the fluid with the rotating cylindrical workpiece during a turning operation. This model is based on relationships that describe cutting fluid atomization, droplet settling, and droplet evaporation. Experiments are performed to validate the model. In Part 1 of the paper, the emphasis is on model development. In the model, thin film theory is used to determine the maximum fluid load that can be supported by a rotating cylindrical workpiece; rotating disk atomization theory is applied to the turning process to predict the mean size of the droplets generated by atomization; and expressions for both the evaporation and settling behavior are established. Droplet size distribution and mass concentration predictions are used to characterize the fluid mist. Model predictions indicate that the droplet mean diameter is affected by both fluid properties and operating conditions, with cutting speed having the most significant affect. Model predictions and experimental results show that the number distribution of droplets within the control volume is dominated by small droplets because of the settling and evaporation phenomena. In Part 2 of the paper, the cutting fluid mist behavior model is validated using the results obtained from a series of experiments. @DOI: 10.1115/1.1765150#

Experimental and analytical efforts to characterize cutting fluid mist formation and behavior in machining.

The use of cutting fluids in machining operations is being carefully scrutinized by industry for several reasons, including its overall cost in the manufacturing process and its impact on worker health. Given the concerns associated with the use of cutting fluids, a number of experimental and analytical research efforts are being conducted to gain an understanding of the role of these fluids in various machining processes. The knowledge gained by this research will aid in the development and implementation of strategies to reduce or eliminate the negative effects of cutting fluids, while maintaining their beneficial role. This article presents the results of designed experiments focused on determining the significant variables that influence air quality during turning operations, as well as characterize the aerosol emissions associated with wet and dry turning. Air quality is characterized by measuring the mass concentration and particle size distribution of the dust and mist created during a set of machining experiments. The relative importance of vaporization/condensation and atomization as mist-generating mechanisms is also explored. The experiments revealed that spindle speed has a dominating effect on both mist mass concentration and aerodynamic particle size. Analytical models are presented that predict the average droplet size of the mist generated by atomization and are used to investigate droplet size trends for various cutting fluids and machining parameters. The results predicted by the models are consistent with the expected trends.

Environmental Attributes of Manufacturing Processes

This chapter examines the ISO 14000 environmental standard, the basic components of Environmentally Conscious Manufacturing, and gives some examples of how they may be integrated in support of an organization’s environmental policy.

Character and Behavior of Mist Generated by Application of Cutting Fluid to a Rotating Cylindrical Workpiece, Part 2: Experimental Validation

Summary and Conclusions This two-part paper has developed and experimentally vali-dated a model for cutting fluid mist formation that describes theinteraction of the fluid with the rotating cylindrical workpieceduring a turning operation. Part 1 of this paper focused on themodel development, incorporating the following components:• Thin film and rotating disk atomization theory to predictmean droplet size.• A lognormal distribution to characterize the droplets that aregenerated.• Relations for both droplet generation and settling rates.• Relations to describe the droplet evaporation.• An expression for mass concentration as a function of thedroplet size distribution.Part 2 of this paper has been devoted to the experimental vali-dation of the model developed in Part 1. The work presented inPart 2 may be summarized as follows:• The experimental setup and capabilities were described.• The mean generated droplet diameter and maximum cuttingfluid flow rate are validated.• The standard deviation was empirically determined using ex-perimental data.• The mist behavior component of the complete model wasvalidated with data collected on both time varying dropletsize distributions and dynamic changes in the mass concen-tration.• The complete model was validated using mass concentrationand size distribution data.Both the model predictions and the measured data point to theimportance of cutting speed as a significant parameter for dropletgeneration and the maximum flow rate. Cutting speed is alsofound to be the dominant variable in terms of mass concentration,with increasing cutting speed producing smaller droplets andhigher PM10 mass concentration levels.Based on the model and the validation effort described in thistwo-part paper, the following conclusions may be drawn:• The complete model accurately predicts the droplet size dis-tribution and the mass concentration behavior.• For the conditions examined, during fluid application themass concentration increases over time because the rate ofdroplet generation exceeds the settling/evaporation rate.• Once the fluid application is discontinued, the mass concen-tration decays exponentially.• The assumption that the droplets within the control volumefollow a lognormal distribution appears to be valid.• Regardless of the droplet mean diameter associated with theatomization mechanism, the distribution of droplets withinthe control volume will be dominated by small droplets be-cause of the settling and evaporation phenomenon.With the present model established, the model may now be usedto judge the effects of processing conditions, fluid applicationvariables, and fluid type on the resulting droplet size distributionand mass concentration.

Development of Cutting Fluid Classification System Using Cluster Analysis

Cutting fluids re receiving increasing scrutiny owing to the potential negative health and environmental consequences of their usage. Manufacturers are besieged with many claims by cutting fluid suppliers and historically fluids have often been selected based on non-technical reasons. A methodology for the development of a classification scheme based on the physical properties of a wide array of cutting fluids is presented. The method of cluster analysis, in a hierarchical agglomerative form, is used to identify differences between fluid samples and a case study example employing this method is used to illustrate the capability of the approach. Results of the example point to unanticipated fluid distinctions and demonstrate the potential for the technique to adequately define cutting fluid categories.

Analytical Models for Economic Demanufacturing Inventory Management

For value recovery activities to be successful in the U.S., the components recovered through demanufacturing operations must be sold at a profit. One of the most important challenges faced by demanufacturing facilities is the management of inventory, which can significantly impact company profitability. In order to achieve profitability, demanufacturers require tools to effectively manage recovered component inventories and scrap/recyclate. In this paper, analytical models are developed to predict the optimal selling quantity and selling period for recovered parts and scrap/recyclate in a demanufacturing system. In addition, total system profit is examined, including break-even conditions.Copyright