Clean Technology

We recommend the adoption of technologies, from machining to clean energy sources to new means of transportation, which lead to sustainable manufacturing.

A team of researchers, led by David Mitlin, Ph.D., is presenting at the 2014 meeting of the American Chemical Society their work on using hemp bast fibers as a cheaper alternative to graphene in supercapacitors for the same or better level of energy and power performance.

When scaled-up it will become an example of applied circular economy principles by using the waste of the clothing and construction industries as feedstock to the electronics industry.

This is an exciting example of the power of materials science in developing clean technologies, substituting scarce resources with cheaper, abundant ones, thus contributing to the adoption of sustainable manufacturing and circular economy principles and practices.


New Application of Old Locomotive Model for Passenger Rail Transportation

Amtrak’s Heartland Flyer interstate passenger train and GE Transportation successful trial of Model P32-8, a biodiesel-fueled passenger locomotive built in Erie (Pennsylvania), is one of TIME magazine’s list of  “The 50 Best Inventions of 2010.”

The appropriately named “Amtrak’s Beef Powered Train” runs on a biodiesel blend, known as B20, that includes beef byproduct (20% pure biofuel and 80% diesel). It is expected to match or surpass the stationary engine test reductions of hydrocarbons and carbon monoxide each by 10 percent,  particulates by 15 percent and sulfates by 20 percent. 


Grind Hardening

DMG / Mori Seiki's Machining Technology Laboratory (MTL) has developed a grinding process called “Grind Hardening”, an opportunity for reducing energy use in and the environmental footprint of typical machining of ferrous materials.


Machine Tools Green Design

The use of green design by machine tool manufacturers has become a competitive advantage in 2010 as customers worldwide are adding demands for resources conservation and other sustainable manufacturing attributes. MAG's new SPECHT® 500/630 horizontal machining center is a great example of incorporating green design for the purpose of minimizing energy and water use and overall footprint reduction.


Automated Energy Monitoring of Machine Tools
                           A. Vijayaraghavan, System Insights Inc., Berkeley, CA
                           D. Dornfeld, LMAS, University of California, Berkeley

Reducing the energy consumption of machine tools can significantly improve the environmental performance of manufacturing systems. To achieve this, monitoring of energy consumption patterns in the systems is required. It is vital in these studies to correlate energy usage with the operations being performed in the manufacturing system. However, this can be challenging due to complexity of manufacturing systems and the vast number of data sources. Event stream processing techniques are applied to automate the monitoring and analysis of energy consumption in manufacturing systems. Methods to reduce usage based on the specific patterns discerned are discussed.

CIRP-2010-Auto Energy Monitoring.pdf

Note: The CIRP paper is re-published courtesy of Professor David Dornfeld, Director of the Laboratory for Manufacturing and Sustainability (LMAS) at the University of California, Berkeley.

Dry and Near-Dry Machining
Machining using coolants (metal removal fluids) or wet machining, although still dominant, can be replaced with two alternative cutting processes at equal or better machining performance. The need to replace wet machining is determined by economic and environmental factors and it leads to sustainable manufacturing processes. The full-cost or life-cycle cost of coolant is estimated at 15 – 20% of the operational cost of a machining process. The full cost includes the costs of purchasing, infrastructure for coolant and air filtration, circulation and disposal, regulatory compliance, machine maintenance.

Dry cutting with no fluid is currently feasible mostly for roughing, milling operations, on a limited number of materials (aluminum, cast iron, carbon steel) using tools with special coating and chip breakers. Near-dry cutting or MQL (Minimum Quantity Lubrication) is a hybrid process between the wet (flooded, conventional coolant/water mixture) and the dry cutting, which can be applied to a larger set of operations (finishing, drilling) and materials, with much reduced environmental and operational costs. MQL uses the minimum quantity of oil/air finely atomized mist (milliliters/hour) delivered directly at the cutting edge in contact with the machined part. MQL usually uses biodegradable vegetable or synthetic oil as cutting fluid. 

Both dry and near-dry processes fit the requirements of a sustainable manufacturing process by reducing energy consumption, cycle-time, mist emissions, bio-hazardous waste, water volume, operating costs, machine maintenance and improving working conditions, air quality, chip recovery and recycling, tool lifetime.

MQL has been successfully adopted in mass manufacturing systems, particularly in the automotive and aerospace industry. Job shops, contract manufacturers, other mass manufacturing companies could implement the two sustainable cutting processes by requiring their suppliers to retrofit existing machines for MQL, where feasible, or investing only in new machines which offer MQL in their design and control system.  

One of the industry benchmarks for MQL adoption, as part of the overall corporate strategy for sustainability, is Ford Motor Company.

For training purposes, we recommend the "Minimum Quantity Lubrication" DVD offered by the Society of Manufacturing Engineers:


Strategies for Minimum Energy Operation for Precision Machining
                              Nancy Diaz, Moneer Helu, Andrew Jarvis,
                              Stefan Tönissen, David Dornfeld, Ralf Schlosser
                              Laboratory for Manufacturing and Sustainability,
                              University of California, Berkeley, WZL, RWTH Aachen

The development of "green" machine tools will require novel approaches for design, production and operation for energy savings and reduced environmental impact. We describe here work on three projects: i. influence of process parameters on power consumption of end-milling using force and process time models with experimental verification. Process parameters are chosen to minimize process time since power consumed by a machine tool is essentially independent of the load and energy per unit manufactured decreases with process time; ii. KERS (kinetic energy recovery system) for machine design and modeling the integration of a recovery system into a machine tool to calculate the amount of energy that could be recovered, and whether the environmental benefits are significant; and iii. evaluation of interoperability solutions, such as MTConnect, as tools enabling a standardized "plug-and-play" platform to integrate sensors with a unified monitoring scheme to achieve improved energy performance.


Note: The MTTRF paper is re-published courtesy of Professor David Dornfeld, Director of the Laboratory for Manufacturing and Sustainability (LMAS) at the University of California, Berkeley.