Clean Manufacturing

The Clean Manufacturing Game Part 1 of 10

2010-06-16T16:23:00.000-07:00

Are You Playing the Clean Manufacturing Game?
A 10 part blog series discussing important aspects of clean manufacturing technology and implementation strategy.

Wasting Away Your Manufacturing Profits – Part 1 of 10

Manufacturing waste is generally thought of as any resource used in a production process that does not go out as part of the product and costs money to get rid of it. However, manufacturing waste also exists in many other forms, for example excessive factory space utilization for equipment (production and waste treatment equipment), inefficient material and process flows, inefficient use of facility labor and lost productivity of both labor and equipment. These types of wastes significantly impact a company’s bottom line too, but are often obscured in overhead accounts or generally overlooked in the manufacturing operation.

In an era of complex business challenges; intense global competitiveness, increasing environmental regulation and energy supply/cost issues, managers must have both lean and green (clean) manufacturing skills necessary to identify and eliminate multifaceted manufacturing wastes in their operations that stealthily steal away business profits. Numerous educational resources are available to manufacturers that teach methods for the identification of and financial accounting of both lean and green wastes. An integrated waste minimization program is being developed by Cleanlogix for use in its CleanTech marketing and sales programs. The new Cleanlogix program is called Cleanopoly™, Clean Manufacturing Strategy Game, and will provide a useful method for determining manufacturing wastes and implementing CleanTech solutions.

Manufacturers of advanced products need state-of-the-art clean manufacturing technology (CleanTech) and CleanTech implementation strategies for successful design and execution of manufacturing waste reduction programs. Manufacturing waste reduction programs may include one or a combination of the following technology components:

• Integrated CleanTech to eliminate or reduce all forms of manufacturing waste: time, labor, space, transport, defect, inventory, processing, equipment, raw materials, air pollution, water pollution, wastewater, solid wastes, and energy wastes.
• Advanced CleanTech for improved quality and reliability imposed by advanced materials, manufacturing methods and processes, and applications.
• Flexible automation, modular and clustered assembly operations (cells) to reduce operational waste.
• More adaptable and flexible production tools and methodologies to improve efficiency and productivity in low volume-high mix-high value production operations.

This series of blog articles provides manufacturing managers with an introduction to clean manufacturing and carbon dioxide (CO2) CleanTech for improving production cleaning, assembly processes and machining operations while eliminating operational and resource waste. CO2 CleanTech prevents or eliminates waste at the source by modifying cleaning, assembly, and machining processes using clean and green chemistry, and unique tool and process implementations. CO2 CleanTech increases both productivity and profitability.

David Jackson is President/CEO of Cleanlogix LLC and serves as the Chief Technology Officer for Cool Clean Technologies, Inc, based in Eagan, MN. He may be reached via e-mail at david.jackson@coolclean.com.

Part 2 of this series introduces clean manufacturing technology.

The Clean Manufacturing Game Part 2 of 10

2010-06-16T16:18:00.000-07:00

Are You Playing the Clean Manufacturing Game?
A 10 part blog series discussing important aspects of clean manufacturing technology and implementation strategy.

Clean Manufacturing Technology (CleanTech) – Part 2 of 10

Clean manufacturing technology (CleanTech) includes equipment, processes, policies, practices and continuous improvement measures that concentrate on optimizing manufacturing resources to minimize or eliminate wastes of various forms. CleanTech helps companies achieve maximum productivity and profitability with minimal waste. CleanTech is a hybrid manufacturing strategy involving Lean Manufacturing techniques; a waste reduction focus that emphasizes manufacturing actions and operations to maximize efficiency, and Green Manufacturing techniques; a waste reduction focus that emphasizes manufacturing actions and operations to minimize environmental waste. Its principal benefit to companies is that CleanTech reduces operating cost in the form of time, transport, chemical management, material consumption, waste treatment, and end-of-pipe pollution control. CleanTech provides opportunities to reduce regulatory obligations, risks, and associated costs, and increases manufacturing process efficiency and productivity.

Thus CleanTech incorporates both Lean and Green elements as an integrated operational strategy to reduce or eliminate both operational and resource wastes as they relate to manufacturing and assembly processes, and is uniquely enabled with advanced CO2 CleanTech.

David Jackson is President/CEO of Cleanlogix LLC and serves as the Chief Technology Officer for Cool Clean Technologies, Inc, based in Eagan, MN. He may be reached via e-mail at david.jackson@coolclean.com.

Part 3 of this series introduces CO2 CleanTech.

The Clean Manufacturing Game Part 3 of 10

2010-06-16T16:15:00.000-07:00

Are You Playing the Clean Manufacturing Game?
A 10 part blog series discussing important aspects of clean manufacturing technology and implementation strategy.

CO2 CleanTech – Part 3 of 10

CO2 clean manufacturing technology (CO2 CleanTech) eliminates or significantly reduces waste generation at the production operation level (i.e., at the source) by modifying manufacturing processes, for example cleaning, assembly processes requiring cleaning, machining operations and thermal spray coating. CO2 CleanTech is uniquely capable of modifying a manufacturing process in numerous ways, as follows:

1. Physically; shape, size, space, application and configuration; and
2. Chemically; solvency, toxicity, wetness, and chemical process.

Owing to CO2’s inherent dry and compatible chemistry, the technology may be implemented directly into a variety of production equipment and process configurations to meet the needs of lean production schemes and product flow constraints, including both existing (aftermarket) and new production implementations.

As an example, replacing conventional surface cleaning agents with CO2’s green chemistry eliminates process inputs such as liquid cleaning solvents, aqueous clean agents, detergents, deionized rinse water, and heated air dryers, among other waste-producing inputs. In another example, CO2-based advanced minimum quantity cooling lubrication (CO2 Machining) replaces flooded cutting fluids and associated waste-producing operations such as fluids management, waste hauling and air pollution control.

Substantial environmental benefits are derived by using CO2 CleanTech. The U.S. Environmental Protection Agency (USEPA) has determined that CO2 is an environmentally benign alternative chemistry for the manufacturing industry because there is no net increase in global warming gases or environmental damage as a result of using CO2. Removing or minimizing the usage of organic compounds such petroleum-derived cutting and cleaning fluids in manufacturing processes and in particular not having to produce as much of these compounds and replacing them with CO2 will lower energy usage, lower emissions of global warming gases, improve water and air quality and natural resource conservation. CO2 is a cost- and performance-effective replacement in a variety of cleaning and machining applications.

Machining and cleaning are two common manufacturing processes, which are typically performed sequentially in a production cycle. Many types of manufacturing wastes are generated in these processes in the form of solvents, water, wastewater, sludge, filters, treatment chemicals, metalworking fluids, air emissions, spills and leaks, damaged equipment, rework or scrap parts, machinery maintenance, cleaner maintenance, boilers, cooling towers, environmental management operations, productivity and energy. Specific examples of precision cleaning and machining activities that produce a waste include:

• Moving products off-line or out of cells to clean them and then returning them back to the line or cell
• Filtering and treating spent alkaline cleaning chemistries
• Monitoring cleaning and machining fluid chemistries
• Rinsing parts
• Drying parts
• Treatment and disposal of spent cleaning and machining agents
• Completing waste hauling manifests
• Environmental reports
• Deionized water treatment
• Rinse water treatment and disposal

Given this, following considers how CO2–enabled machining and cleaning operations can eliminate many of these waste elements:

• Materials selection and productivity: Recycled CO2 itself does not generate waste, does not require environmental management, and eliminates equipment cleaning and maintenance.
• Energy conservation: Using recycled CO2 eliminates the need for additional energy to heat cleaning baths, dry parts, or evaporate and concentrate wastes.
• Waste reduction and elimination: CO2 does not itself become a waste by-product. CO2 eliminates the wasteful consumption, treatment and disposal of water, wastewater and associated solid wastes.
• Air pollution reduction: Recycled CO2 is not considered an air pollutant, is non-toxic and is odorless within the factory atmosphere.
• Space and process step reduction: CO2-enabled cleaning processes can reduce multiple processing steps to a single step and perform in less space, sometimes no extra space is needed if the CO2 process is integrated directly with an existing manufacturing tool such as a bonder, dispenser, or machining tool.

David Jackson is President/CEO of Cleanlogix LLC and serves as the Chief Technology Officer for Cool Clean Technologies, Inc, based in Eagan, MN. He may be reached via e-mail at david.jackson@coolclean.com.

Part 4 of this series gives some examples of how CO2 cleaning technology cleans up the factory.

The Clean Manufacturing Game Part 4 of 10

2010-06-16T16:11:00.000-07:00

Are You Playing the Clean Manufacturing Game?
A 10 part blog series discussing important aspects of clean manufacturing technology and implementation strategy.

Cleaning up the Factory – Part 4 of 10

Advanced CO2 cleaning technology includes CO2 composite sprays (NOT Snow Guns or Sprays!), plasmas, hybrid sprays, centrifugal liquid carbon dioxide immersion systems, supercritical fluid extraction systems, and fluids purification and management systems. This technology is available in stand-alone, mobile, bench-top, robotic, cleanroom, and production equipment integration modules (i.e., CPUs). CO2 cleaning and surface treatment applications are diverse and include precision degreasing, departiculation, outgassing, drying, disinfection and surface modification and functionalization.

CO2 CleanTech delivers both lean and green waste reduction benefits to manufacturers including the elimination of toxics, reduction of cleaning steps, lower energy costs and improved cleaning quality and consistency, among many other benefits. For example, a major ball point pen manufacturer installed a CO2 centrifugal degreasing system to replace an ultrasonic PERC solvent cleaning system. The new CO2 cleaning system cleaned faster, better and allowed lubricating oils to be recycled back into the machining process. Annual operating costs decreased by more than $130,000 per year during the first year of service and resulted in more than a $1,500,000 in operating cost reductions over a 10 year installation period. In another example, a major hard disk drive manufacturer reduced cost-per-clean by over 70% by eliminating the manufacturing wastes associated with parts disassembly, aqueous cleaning and deionized water rinsing, and drying operations. In another example, a major printer manufacturer eliminated multiple cleaning steps with a single-step CO2 composite spray (solid-plasma) cleaning process, which increased product yield while eliminating a number of manufacturing wastes.

David Jackson is President/CEO of Cleanlogix LLC and serves as the Chief Technology Officer for Cool Clean Technologies, Inc, based in Eagan, MN. He may be reached via e-mail at david.jackson@coolclean.com.

Part 5 of this series introduces clean machining technology.

The Clean Manufacturing Game Part 5 of 10

2010-06-16T16:07:00.000-07:00

Are You Playing the Clean Manufacturing Game?
A 10 part blog series discussing important aspects of clean manufacturing technology and implementation strategy.

Clean Machining – Part 5 of 10

The literature suggests that operational costs related to the use of flooded cooling lubricants can range between 7% and 17% of the total costs of the manufactured workpiece. Intangible costs to a business must also be considered. For example, cutting fluids, especially those containing petroleum oils, have become a huge liability. No matter how safe and environmentally friendly a cutting fluid may be, governmental regulations demand special handling the moment it is poured into a sump.

A new cooling-lubrication technology called CO2 machining has been recently introduced. CO2 machining provides superior penetration, cooling, cleaning and lubricating capability for very demanding machining applications. CO2 machining resolves many of the waste characteristics of conventional machining fluid processes and can be implemented along side many older and newer metalworking machinery, tools and fluids for cleaner and leaner machining operations.

The CO2 machining system combines a source of propellant gas (i.e., compressed air), minute amounts of bio-based lubricants (i.e., soybean oil), and CO2 in various concentrations to form an infinitely adjustable cooling lubricant spray. CO2 machining systems employs a novel Coanda-coaxial injector and spray applicator and controls machining heat by using both a physical and chemical effect. Frictional heat generated at the cutting edge is eliminated through the delivery of reactive lubricants (chemical effect), including carbon dioxide (CO2) gas, which produce beneficial tribochemical reactions. The majority of the machining heat produced by the deformation of the material itself is removed using adjustable spray compositions containing microscopic particles of solid carbon dioxide, which impact hot surfaces at high velocity and remove heat through a phase change (physical effect) phenomenon.

David Jackson is President/CEO of Cleanlogix LLC and serves as the Chief Technology Officer for Cool Clean Technologies, Inc, based in Eagan, MN. He may be reached via e-mail at david.jackson@coolclean.com.

Part 6 of this series discusses bio-based lubricant technology.

The Clean Manufacturing Game Part 6 of 10

2010-06-16T16:04:00.000-07:00

Are You Playing the Clean Manufacturing Game?
A 10 part blog series discussing important aspects of clean manufacturing technology and implementation strategy.

Bio-based Lubricant CleanTech – Part 6 of 10

Renewable bio-based lubricants provides an environmentally sound and worker friendly alternative to petroleum-based cooling lubricants. Vegetable-based lubricants offer significant advantages such as superior tool lubricity, better surface finish, higher feed rates and a safer chemistry. Using a bio-based lubricant in minimum quantity application eliminates the costs associated with treatment, environmental compliance, and disposal, among other operational cost factors. Moreover, vegetable oils such as soybean oil exhibit natural rust inhibition on metal surfaces, a very important characteristic for ferrous machining applications.

Compared to petroleum-based fluids, bio-based lubricating fluids perform as well as or better when machining steel and aluminum, cooling and lubricating the cutting surface as it removes small metal chips and allowing faster, more accurate machining to be done. Bio-based lubricating fluids are biodegradable, non-toxic, have low volatile organic compounds (VOCs) emissions, a high flash point and no offensive odor.

The initial purchase of a cutting fluid is merely the beginning of a much more expensive endeavor. According to a TechSolve, Inc., a non-profit testing laboratory based in Cincinnati, Ohio, for every $1 of coolant purchased, operational costs associated with using, maintaining and disposing of it can be more than $10. The real costs associated with cutting fluid purchases include the labor involved in mixing and transporting the fluids as well as machine draining and cleaning. In addition, deionized water make-up and coolant concentrate replenishment costs with coolant maintenance and disposal costs all contribute to a very high coolant life-cycle cost.

CO2 machining with bio-based lubricant additives eliminates the high cost of machining coolants and provides the opportunity to increase machining productivity in the form of longer tool life, increased speeds and depths of cut, and increased machine utilization, all of which can substantially improve the profitability of a machining operation.

David Jackson is President/CEO of Cleanlogix LLC and serves as the Chief Technology Officer for Cool Clean Technologies, Inc, based in Eagan, MN. He may be reached via e-mail at david.jackson@coolclean.com.

Part 7 of this series discusses CO2 CleanTech for thermal spray coating operations.

The Clean Manufacturing Game Part 7 of 10

2010-06-16T16:01:00.000-07:00

Are You Playing the Clean Manufacturing Game?
A 10 part blog series discussing important aspects of clean manufacturing technology and implementation strategy.

Cool and Clean Under Fire – Part 7 of 10

Thermal spray coating uses a spray gun of one form or another to deposit finely divided and molten materials onto a substrate. Various materials, including metals and alloys, carbides, polymers, lubricants, ceramics, cermets and composites, can be thermally sprayed onto a substrate to protect critical components, rebuild worn surfaces and to reduce friction. For example, sprayed coatings are widely used to rebuild worn machine parts or to re-manufacture used equipment.

Precision surface preparation is a critical step prior to most thermal coating applications. The majority of coating failures occur at the coating-substrate interface. The reason for this is the discontinuity in the materials system (i.e., mismatched cohesion energies) and/or an improperly prepared bonding surface (i.e., cleanliness and surface area). Proper surface preparation insures that the adhesion between the first splat layer and substrate is strong. Oxides, microscopic particles and hydrocarbon films on bonding surfaces will reduce or prevent local bonding. Surface roughening with microabrasive grit blasting, for example using aluminum oxide particles, removes surface oxides while increasing the bonding surface area for the purpose of providing mechanical keying or anchoring of the first layer of solidified coating. A follow-on precision cleaning operation is used to remove ablated surface and microabrasive particles which typically populate newly formed surface topography.

Besides microscopic particles, oxides and hydrocarbons, another thermal coating process contamination is heat. During thermal spray coating processes such as flame spray, electric-arc (wire-arc) spray, plasma spray and detonation gun spray, substrates are subjected to very high and localized spray temperatures. Under continuous treatment, the temperature of a substrate will increase as the molten coating contacts and heats the surface. It is believed by experts in the field of thermal coating that if thermal migration and build-up is not managed, coating adhesion is greatly affected by the mismatch in thermal expansion or temperatures between a coating and substrate surface. For example, related to adhesion is splat formation during the application of a thermal sprayed coating.

Finally, following thermal coating of precision components, machining of coated surfaces to dimension the coating may be performed. As discussed above, machining heat must be managed properly to increase tool life, improve surface finish and increase the productivity of the machining operation.

A CO2 composite spray uniquely manages the variety of contamination present in a thermal spray coating operation, eliminating the need for separate cleaning fluids, cooling agents and machining agents.

David Jackson is President/CEO of Cleanlogix LLC and serves as the Chief Technology Officer for Cool Clean Technologies, Inc, based in Eagan, MN. He may be reached via e-mail at david.jackson@coolclean.com.

Part 8 of this series discusses a new surface inspection CleanTech called Optically Stimulated Electron Emission (OSEE).

The Clean Manufacturing Game Part 8 of 10

2010-06-16T15:57:00.000-07:00

Are You Playing the Clean Manufacturing Game?
A 10 part blog series discussing important aspects of clean manufacturing technology and implementation strategy.

Look, but Don’t Touch – Part 8 of 10

Contamination is a relative term and can be defined as any foreign substance contained on a surface at a level that prevents the production of reliable, complex hardware. Examples of surface contamination include particles, soils, oxidation, electrostatic charge, radioactivity, and heat. The purpose of cleaning or modifying a surface is to produce a surface free of, or with acceptable levels of, contamination.

In conventional cleaning operations, products are typically removed from a (contaminant-generating) manufacturing process (and line) at a certain point, cleaned to remove contamination to an acceptable level, inspected to verify cleanliness, and returned to the production line for further value-add manufacturing steps. Example iterations include machining-cleaning-inspection, assembling-cleaning-inspection, cleaning-inspection-bonding, and cleaning-inspection-welding. A variety of analytical methods may be employed to verify surface cleanliness, all of which generates space, labor, and transport wastes.

A new non-contact surface inspection technology called Optically Stimulated Electron Emission (OSEE) offer a unique way of addressing these manufacturing wastes. Optically Stimulated Electron Emission (OSEE) inspection is a unique CleanTech for non-invasive, non-contact analysis of surfaces to determine contamination levels. This technique utilizes a tool which utilizes ultraviolet radiation to create electron emission from a surface, resulting in a small current detected by the inspection tool. Electron emission is dependent on the substrate's surface chemistry; hence the electron emission characteristics will change with the presence of a contaminant on the surface, generally by attenuating the signal. OSEE inspection combined CO2 CleanTech is a dynamic duo that provides a number of clean manufacturing benefits.

David Jackson is President/CEO of Cleanlogix LLC and serves as the Chief Technology Officer for Cool Clean Technologies, Inc, based in Eagan, MN. He may be reached via e-mail at david.jackson@coolclean.com.

Part 9 of this series discusses robot CleanTech.

The Clean Manufacturing Game Part 9 of 10

2010-06-16T15:53:00.000-07:00

Are You Playing the Clean Manufacturing Game?
A 10 part blog series discussing important aspects of clean manufacturing technology and implementation strategy.

Robots to the Rescue – Part 9 of 10

Robot CleanTech has become a mainstay due to their flexibility, reliability and repeatability. Prior to robots, material handling and machine tending applications were purely a manual task. Operators transporting material from one fixture or machine to the next, waiting on the equipment to finish its task, and then relocation of the processed part or parts to another tool or process fixture; these were some of the most common manual tasks that required several operators to manufacture the product. These material handling and machine tending tasks are now almost always accomplished using robots, especially in operations requiring high speed and accuracy.

The advantages of Robot CleanTech include:

• No wait time for operators since the robots are performing material handling and wait times could be absorbed by having them perform additional processing operations if possible.

• Robots have negligible downtime resulting in limited production loss

• Robots are inexpensive to operate in the long run compared to manual labor and the return on investment can be fast based on the demand for the manufactured product.

• Robots are repeatable to a high degree of accuracy which results in lowered scrap parts once the robot tasks are optimized.

While standard off the shelf robots have one arm to which you can mount tooling, the advent of tool changers and dual equipment end-of-arm tool (EOAT) design have helped make robotic operations more flexible and lean in terms of higher per cycle utilization. In the die cast industry, robots are currently being used for material handling parts as well as de-gating and finishing operations like deburring and grinding. In the Automotive industry, robots in body shop applications are in some cases used for material handling of parts as well as welding or sealant application through the use of dual application end-effectors or floor mounted pedestal equipment. In applications involving multiple product models, tool changing equipment can be used for robots to disengage/engage new EOATs. Servo motor driven external axes allow robots to be more flexible by acting as auxiliary axes of motion to ensure maximum robot utilization.

This flexibility that allows engineers to process as many operations as possible within the given cycle time and feasibility constraints helps make manufacturing processes lean. Robot vendors have already developed robots with multiple arm configurations. In the future, these multi-arm robots will be more of the norm with operations that are faster, more efficient and lean.

Vision systems are being used in combination with robots to help inspect parts for feature existence and feature sizes. Vision systems are more commonly used on robots to act as dynamic guidance systems that allow robots to vary their motion targets based on vision generated guidance information. Vision technology and robots are a natural pairing and the combination has resulted in making robotic operations leaner than ever before.

Operations such as racking and de-racking of parts, part picking from bins, visual inspection of parts, which were normally handled by human operators, are now being performed by robots with higher consistency, accuracy, repeatability and speed due to vision systems used in conjunction with the robots. Finishing operations such as routering, grinding, sealing are now being applied more accurately with fewer imperfections and scrap parts thereby contributing solidly to lean manufacturing. In the inspection arena, robots are utilized heavily in Flexible Measurement Systems (FMS). Robots mounted with vision cameras to collect feature information for multiple inspection locations have resulted in a drastic reduction in the number of vision cameras and fixtures required to inspect parts. In the past, the same inspection would have been performed with several fixed vision cameras.

One of the primary drivers to automate a manufacturing process using robots is the safety factor. Most manufacturing operations have a degree of human injury risk. Some simple part transfer operations may be safe for humans to perform while others like unloading parts from a press/die or foundry operations with molten metal are definitely not fit for manual operations. In these cases, robots are invaluable in lowering risk to humans.

An unsafe workplace leads to human inefficiency driven by fear. This in turn leads to lowered production rates and employee retention. A safe and secure workplace improves morale and lowers costs, which in turn improves the bottom line. Unsafe working environments can lead to waste in terms of effort and time.

The above cases are just a few examples of how robots, if used correctly, can contribute to cleaner manufacturing. Robots help achieve higher production quality at a reduced operating cost compared to manual manufacturing. They help produce more parts with fewer defects using less equipment while maintaining their flexibility for future changes.

The most significant impact to clean manufacturing related to robot CleanTech lies in their ease of use. Programming robots to perform manufacturing operations has evolved into an easy-to-use PC-based process that can be easily understood and applied by engineers as well as skilled trades at the plant floor.

CO2 CleanTech utilizes robots to provide reliability, accuracy, consistency and capacity. Robot CleanTech is also used to transport product through combination processes involving spray, immersion and plasma treatments, and production operations such as assembly, machining, soldering, and bonding.

David Jackson is President/CEO of Cleanlogix LLC and serves as the Chief Technology Officer for Cool Clean Technologies, Inc, based in Eagan, MN. He may be reached via e-mail at david.jackson@coolclean.com.

Part 10, the last part of this series, discusses thinking clean.

The Clean Manufacturing Game Part 10 of 10

2010-06-16T15:47:00.000-07:00

Are You Playing the Clean Manufacturing Game?
A 10 part blog series discussing important aspects of clean manufacturing technology and implementation strategy.

Thinking Clean – Part 10 of 10

Clean manufacturing is a change of mindset - changing the conventional production paradigm using non-traditional lean and green manufacturing game rules. This is thinking clean. A clean manufacturing strategy involves training in the relevant CleanTech, followed by proper planning, assessment, and analysis of the various manufacturing wastes produced. The new clean manufacturing game involves a skillful and diligent waste auditing process that overlays state-of-the-art CleanTech onto a conventional production model – line, tool and process – to produce a new clean-enabled line, tool and process. Winning the clean manufacturing game is experiencing improved productivity and profitability.

For example in manufacturing operations that produce high reliability hardware, a product may be cleaned several times through the production cycle (build-clean). Manufacturing and assembly operations requiring a product cleaning include cutting, drilling, trimming, micromachining, bonding, dicing, abrasive finishing, polishing, stamping, welding and inspection. Conventionally, precision cleaning is performed as an “island” operation using, for example, a stand-alone spray cleaner, vapor degreaser, ultrasonic cleaning system, rinsing and drying stations. Segregation of the cleaning process from the assembly tool has been a necessity due to the inherent chemical and physical (space) incompatibilities between conventional cleaning operations and most assembly processes and tools. CleanTech changes this conventional paradigm.

CO2, Robot and OSEE Inspection CleanTech can be integrated with virtually any production tool or process to produce numerous new and advanced clean-enabled tools; Clean-Assembly™ tools. Clean-Assembly tools are much more productive because two or more assembly processes are be performed simultaneously within the same work cell. Products don't have to be transported from, cleaned, inspected and transported back to the production line - resulting in reduced labor, higher throughput, increased quality and decreased production space. The Clean-Assembly CleanTech model changes the game rules by incorporating the non-value add (although necessary waste), processes with the value-add production operations. This significantly reduces manufacturing waste and improves both productivity and profitability.

Conclusion

In today’s manufacturing environment, there is a need to reduce waste and improve profitability. This is accomplished using flexible and adaptable production methodologies, cleaner, leaner and drier process chemistries, and an increasing use of clustered production processes (cells). Production steps previously performed as separate operations using separate tools, space, transport, time, and labor) may now be integrated into modular lean cells using CO2 technology. Space and time saving hybridized forms of assembly processes integrated with CO2 technology may be used. In-situ clean-assembly tools may be clustered with manufacturing operations in modular production cells in which two or more steps can be performed simultaneously, thereby increasing throughput and yield and reducing human interaction and cost of ownership.

The bottom line is that CleanTech, and CO2 CleanTech in particular, reduces manufacturing waste and reduces operational costs in a number of unique ways. It's worth the effort to employ CleanTech where possible to improve productivity and profitability.

David Jackson is President/CEO of Cleanlogix LLC and serves as the Chief Technology Officer for Cool Clean Technologies, Inc, based in Eagan, MN. He may be reached via e-mail at david.jackson@coolclean.com.

Select Clean Manufacturing References:

1. An Introduction to Environmental Accounting as a Business Management Tool, United States Environmental Protection Agency, EPA 742-R-95-001, June 1995.
2. Lean Manufacturing and the Environment: Research on Advanced Manufacturing Systems and the Environment and Recommendations for Leveraging better Environmental Performance, United States Environmental Protection Agency, EPA 100-R-03-005, October 2003.
3. The EPA Manual for Waste Minimization Opportunity Assessments, United States Environmental Protection Agency, EPA/600/2-88-025, April 1988.
4. How to Be Green and Stay in the Black, Department of Navy, NAVSO P-3680, October 1997.
5. Schwendeman, T., “Pollution Prevention Can Pay”, Industrial Heating, December 2003.
6. Jackson, D. et al, “Today’s Forecast – It Looks like Snow”, Precision Cleaning, Volume VII, Number 5, May 1999.
7. Darvin, C. et al, “ Demonstration of Liquid CO2 as an Alternative for Metal Parts Cleaning, Precision Cleaning, Volume IV, Number 9, September 1996.
8. Chittick, R.C., “Using CO2 Snow to Correct Drive Level Dependence in Quartz Crystal Resonators”, Precision Cleaning, Volume V, Number 6, June 1997.
9. Jackson, D., “Liquid CO2 Immersion Cleaning- The Users Point of View”, Parts Cleaning, pp 32-37, April 1999.
10. Jackson, D., “Making the Case for CO2”, CLEANTECH, February 2004.
11. Jackson, D., “CO2 in the Miniature Manufacturing Process”, MicroTEC, October 2004.
12. The Role of Robots in Lean Manufacturing, http://www.robotics.org.
13. Chawla, M., “Measuring Surface Cleanliness”, Precision Cleaning, June 1997.
14. Jackson, D, “Setting the Record Straight: CO2 Technology is Part of the Solution”, EHS Today, August 2009.
15. Jackson, D., “CO2 for Complex Cleaning”, Process Cleaning, July/August 2009.
16. Jackson, D. et al, "Advanced CO2 Cleaning and Machining Options for Rolling Element Bearings", ASTM Rolling Element Bearings Workshop, May12-14, 2009.
17. Jackson, D. et al, “Automated CO2 Composite Spray Cleaning System for HDD Rework Parts”, Journal of the IEST, V. 52, No. X, 2009.
18. Jackson, D. et al, “CO2 Cooling for Thermal Spray Advances”, SprayTime – Thermal Spray Association, First Quarter 2009.
19. Jackson, D., “A Versatile Manufacturing Technology for Thermal Spray Operations”, ASM/TSS Aerospace Coatings Symposium 2008.
20. Jackson, D., “Changing the Game Rules with CO2 – CO2 Machining Fluid Technology”, SME/IMTS September 2008.
21. Jackson, D., “CO2 Composite Spray Technology for Probe Card Cleaning”, SW Test Workshop, June 2008.

High-performance dry machining fluid options for the tool room

2009-01-06T15:38:00.000-08:00

The work performed on tool room machines is prototype or short run jobs and there is rarely the opportunity to optimize tooling, feeds or speeds. The machine and cutting tools must be able to absorb punishment from processes that are much less refined than can be achieved on longer runs using automated machines. Over the years there has been a continuous evolution in metalworking tool room equipment capabilities, with the exception being coolant-lubricant options.

Equipping manual or CNC-enabled open machining platforms such as knee-mills, bed-mills, drills, tool grinders and lathes with flooded coolant systems leaves the tool room equipment, operators and floors awash. When flooding is not possible or desired, this leaves air-oil or air-only lubricating and cooling options. However these near-dry and dry machining fluid options are very limiting, in particular for hard machining applications and work requiring only dry machining and producing lots of tool heat.

Portable and adaptable dry and near-dry CO2 composite spray machining fluid technology offers the tool room machinist with productivity and machining quality improvements as good as or better than those achieved with high pressure flooded coolants, but without the mess. CO2 composite sprays offer a unique set of cooling and lubricating capabilities to enable machining of harder, more abrasive materials and using more capable and expensive cutting tools. Cutting tools last longer and parts are machined cooler, quicker and cleaner with improved surface finishes. Tool room machines, floors and air stay clean.
David Jackson serves as the Chief Technology Officer for Cool Clean Technologies, Inc, based in Eagan, MN.

Dimensional grinding using composite CO2 machining fluids

2009-01-06T15:36:00.000-08:00

During dimensional machining of a polymer-coated precision valve spool, a Norton 80 grit grinding wheel generates temperatures of up to 450 degrees F. A traditional coolant-lubricant approach requires interrupted processing to provide substrate dimensional control due to thermal expansion, in particular the polymer-metal interface.

A composite CO2 machining fluid spray (Air, MQL-Soy oil and carbon dioxide particles) directed into the grinding zone is able to maintain substrate temperatures to under 90 degrees F. Efficient removal of excess heat with minimal oil lubrication during precision grinding allows the machining operation to proceed to completion in a single and continuous step with reduced cycle time and improved dimensional stability.

An additional benefit of using this unique machining fluid technology with precision grinding includes a potential for significantly reducing wheel dressing intervals. In this particular application a 50% increase in parts production was realized between wheel dressing intervals.
David Jackson serves as the Chief Technology Officer for Cool Clean Technologies, Inc, based in Eagan, MN. He may be reached via e-mail at david.jackson@coolclean.com.

CO2 Composite Spray Machining: An Introduction (Part 2)

2009-01-06T15:27:00.000-08:00

In the previous blog, CO2 composite spray technology was introduced with a focus on basic components and operational characteristics of a spray system. This blog completes the introduction with a description of various performance aspects of a CO2 composite spray and includes initial laboratory test results for this new machining fluid technology.

Managing Heat

A CO2 composite spray manages machining heat through both physical (thermal transfer) and chemical (i.e., Rehbinder) effects. Frictional heat generated at the cutting edge is eliminated indirectly using chip-tool-workpiece temperature control and directly through juvenile surface reactions using a suitable lubricant chemistry, including carbon dioxide itself. Efficient heat removal is achieved through adjustable heat capacity, phase change phenomenon and reactive chemistry within the spray.

Penetration and Sticking Power

For CO2 composite sprays of the second kind, the combination of sublimating solid coolant and subcooled lubricants (mass) with near-sonic air flow (velocity) creates significant surface penetration power (Force = mass x velocity), which allows the coolant and lubricant particles to penetrate deeply into cracks and crevices and intimately contact machining surfaces. Particle velocities of between 50 m/s and 300 m/s are easily obtained with CO2 composite sprays. Upon entering the cutting zone, the cooling lubricant spray provides chip cooling and chip evacuation during sublimation or evaporation of the CO2. During expansion, electrostatically-charged CO2 gas and lubricant uniformly coat and penetrate cutting interfaces. Compared to conventional high pressure flooding techniques, CO2 composite sprays operating at 120 psi can exert particle-fluid impact stresses of over 8,000 psi.

Cutting Performance

In standardized cutting tests (see Table 1 below) performed by an independent testing laboratory (TechSolve, Inc., Cincinnati, Ohio), it was demonstrated that CO2 composite sprays using a bio-based oil additive outperformed conventional flood processes using standards: synthetic oil, soluble oil, and semi-synthetic fluids with extreme pressure agents, in terms of both uniform tool wear and cutting force (see CO2 Composite Spray data line 1 in the cutting force figure below).

Hard Machining Advantages

CO2 composite sprays offer several technical advantages and opportunities for challenging machining applications involving superhard tools and hard or abrasive substrates. These include:

• Supercharge existing cutting fluid chemistries in minimum and bulk amounts with increased coolant power and cutting zone penetration
• Increase machining efficiency for harder and more abrasive materials
• Improve surface finish
• Test new advanced coolant-lubricant additives in minimum quantities on-the-fly without having to change-out coolant sumps
• Optimize challenging machining processes with customized combinations of coolant, lubricant and advanced cutting tool coatings such as PCD, CBN and coated HSS

Another advantage provided by CO2 composite sprays is that they are a very clean and lean technology. Implementing CO2 composite spray technology can reduce or eliminate the use of flood coolants. This conserves fossil fuels, water and energy, and eliminates (or reduces) the generation of nonproductive outputs, hazardous wastes, air emissions, wastewater, or other pollutants.

Wrap-Up

CO2 composite spray technology improves machining productivity while reducing operating costs and environmental pollution. CO2 composite spray technology can be implemented along side many older and newer machining and metalworking processes, including machinery, materials, methods, processes, cutting tools and fluids, augmenting a successful conversion to a clean and lean metalworking operation.
Future blog articles will focus on specific commercial machining applications and challenges which have been addressed with CO2 composite technology.

David Jackson serves as the Chief Technology Officer for Cool Clean Technologies, Inc, based in Eagan, MN. He may be reached via e-mail at david.jackson@coolclean.com.

In the previous blog, CO2 composite spray technology was introduced with a focus on basic components and operational characteristics of a spray system. This blog completes the introduction with a description of various performance aspects of a CO2 composite spray and includes initial laboratory test results for this new machining fluid technology.

Managing Heat

A CO2 composite spray manages machining heat through both physical (thermal transfer) and chemical (i.e., Rehbinder) effects. Frictional heat generated at the cutting edge is eliminated indirectly using chip-tool-workpiece temperature control and directly through juvenile surface reactions using a suitable lubricant chemistry, including carbon dioxide itself. Efficient heat removal is achieved through adjustable heat capacity, phase change phenomenon and reactive chemistry within the spray.

Penetration and Sticking Power

For CO2 composite sprays of the second kind, the combination of sublimating solid coolant and subcooled lubricants (mass) with near-sonic air flow (velocity) creates significant surface penetration power (Force = mass x velocity), which allows the coolant and lubricant particles to penetrate deeply into cracks and crevices and intimately contact machining surfaces. Particle velocities of between 50 m/s and 300 m/s are easily obtained with CO2 composite sprays. Upon entering the cutting zone, the cooling lubricant spray provides chip cooling and chip evacuation during sublimation or evaporation of the CO2. During expansion, electrostatically-charged CO2 gas and lubricant uniformly coat and penetrate cutting interfaces. Compared to conventional high pressure flooding techniques, CO2 composite sprays operating at 120 psi can exert particle-fluid impact stresses of over 8,000 psi.

Cutting Performance

In standardized cutting tests (see Table 1 below) performed by an independent testing laboratory (TechSolve, Inc., Cincinnati, Ohio), it was demonstrated that CO2 composite sprays using a bio-based oil additive outperformed conventional flood processes using standards: synthetic oil, soluble oil, and semi-synthetic fluids with extreme pressure agents, in terms of both uniform tool wear and cutting force (see CO2 Composite Spray data line 1 in the cutting force figure below).

Hard Machining Advantages

CO2 composite sprays offer several technical advantages and opportunities for challenging machining applications involving superhard tools and hard or abrasive substrates. These include:

· Supercharge existing cutting fluid chemistries in minimum and bulk amounts with increased coolant power and cutting zone penetration
· Increase machining efficiency for harder and more abrasive materials
· Improve surface finish
· Test new advanced coolant-lubricant additives in minimum quantities on-the-fly without having to change-out coolant sumps
· Optimize challenging machining processes with customized combinations of coolant, lubricant and advanced cutting tool coatings such as PCD, CBN and coated HSS

Another advantage provided by CO2 composite sprays is that they are a very clean and lean technology. Implementing CO2 composite spray technology can reduce or eliminate the use of flood coolants. This conserves fossil fuels, water and energy, and eliminates (or reduces) the generation of nonproductive outputs, hazardous wastes, air emissions, wastewater, or other pollutants.

Wrap-Up

CO2 composite spray technology improves machining productivity while reducing operating costs and environmental pollution. CO2 composite spray technology can be implemented along side many older and newer machining and metalworking processes, including machinery, materials, methods, processes, cutting tools and fluids, augmenting a successful conversion to a clean and lean metalworking operation.

David Jackson serves as the Chief Technology Officer for Cool Clean Technologies, Inc, based in Eagan, MN. He may be reached via e-mail at david.jackson@coolclean.com.

2008-02-04T09:40:00.000-08:00

CO2 Composite Spray Machining: An Introduction (Part 1)
- David Jackson, Cool Clean Technologies

Background

Carbon dioxide (CO2 gas, solid, liquid) as a machining fluid and its beneficial impacts on machining operations with regards to both lubricating and cooling qualities has been studied for the past 60 years. One of the earliest documented metal cutting processes utilizing a carbon dioxide spray is described by Thompson Products (later TRW) in the early 1950’s (1). The literature contains several good examples of the benefits that can be realized with a CO2 based machining fluid. With regards to tool wear, a reduction in CBN tool wear has been noted when CO2 gas is admitted to the atmosphere of the cutting zone, removing oxygen and reducing oxidation (2). With regards to tungsten carbide tool wear, it has been observed that liquid CO2 sprayed at base of carbide tool tip retards crater wear (3). In another investigation, it was observed that CO2 gas increases tool life by allowing a larger, protective BUE to form on HSS (4). Gases such as CO2 not only lubricate, but also cool. This point has been illustrated with cooled gases in many applications (5). For example, tool life increases when CO2 gas is cooled to -40° C to -60° C, even when cutting forces rise (6-8).

Limitations and shortcomings associated with conventional carbon dioxide machining fluid sprays of the past include, among others, a lack of fluid compositional control, limited lubrication ability, lack of temperature and penetration control, and limited machine-tool adaptability. These issues are being addressed with a new CO2 machining spray technology – CO2 Composite Spray Machining comprising gas-solid, gas-solid-liquid and gas-liquid compositions.

Conventional Coolants and Lubrication

Literally thousands of different cooling lubrication formulations are available on the market for the many different types of machining processes, equipment, cutting tools and materials. Besides machinability issues related to cooling lubricants, selection factors include machine/tool compatibility, sump stability, foaming characteristics, filterability, toxicity, biodegradability, odor, misting, surface wetting, staining, surface cleanliness and disposal issues. Cooling lubrication formulations are tested and selected based on its ability to provide the best mix of all of these characteristics, the tradeoffs being between machining and non-machining performance characteristics.

Alternatives to current practices are getting more serious consideration in response to environmental and operational cost pressures. Alternatives to flood machining include dry machining, near-dry machining (NDM) or minimum quantity lubrication (MQL) machining. The MQL approach utilizes a small amount of an oil of one type or another which is entrained as microscopic droplets in an airstream and delivered as a coherent dry (air only), near-dry, and wet machining spray. Bio-based lubricating oils derived from soybeans or other vegetable products are also being utilized successfully with MQL. Natural oils have numerous MQL advantages, including a polar chemistry which reacts more favorably with metal surfaces, unsurpassed lubricity, and an abundant U.S. agricultural growing capacity. MQL performance studies in machining processes such as milling, grinding and drilling show great promise. However issues related to tool adaptation and cooling capacity continue to be barriers to widespread adoption of MQL and other near-dry or dry machining technologies.

CO2 Composite Spray Machining

A new carbon dioxide (CO2) based cooling lubrication technology – comprising CO2 composite sprays - has been developed and is in its early market introduction period. CO2 composite spray technology employs robust spray compositional and energy control capability which have been developed to resolve many of the limitations found in more advanced cooling alternatives such as LN2 and CO2 machining sprays, while delivering beneficial physicochemical machining actions and benefits provided by conventional MQL. CO2 composite spray machining employs unique and beneficial combinations of lubrication and cooling technologies:

- Minimum amounts of carbonated coolants and lubricants
- Coanda effect for additive injection and spray trajectory control (see figure below)
- Precise machining spray temperature control
- Precise cooling lubrication composition control
- Electrostatic charging (Passive/Active) of cooling lubrication compositions for improved droplet formation and cutting zone deposition
- Pressure and flow control for enhanced penetration, flushing and lubricant deposition

CO2 composite spray technology includes three general kinds of compositions:

1st Kind (Dry): Gas (Air)-Solid(CO2)
2nd Kind (Near-Dry): Gas (Air)-Solid(CO2)-Liquid(MQL)
3rd Kind (Flood): Gas (CO2)-Liquid(Coolant/Lubricant)

This paper focuses primarily on CO2 composite spray systems of the second kind – a gas-solid-liquid composition – and fluid phenomenon associated with same. A gas-solid-liquid composition combines a source of propellant gas (i.e., compressed air), lubrication additives (i.e., soy oil), and solid and/or gaseous CO2 (i.e., coolant) in various proportions to form an infinitely adjustable cooling lubricant spray. For lubricant-based CO2 composite sprays, a Coanda-Coaxial lubricant injector and spray applicator are applied as an external spray. Spray applicators employ a passive electrostatic charging mechanism to enhance droplet uniformity, spray force and machined surface deposition. Alternatively, an electrostatic charging system may be employed to provide combination spray charging capability. An important performance aspect associated with composite CO2 machining sprays, and unlike conventional LN2 and CO2 (flood) machining sprays, is that dilute mixtures containing solid coolant particles and subcooled lubricants more easily access and interact (high frequency impacts) with cutting surfaces and interfaces. Concentrated particle or fluid streams tend to “pack” the surface during impact which retards physical actions such as outflow velocity and heat exchange.

Chemistry and Control

CO2 composite spray chemistries combine several chemical and physical cooling and lubrication ingredients and are formed and delivered on-the-fly. The sprays are infinitely adjustable and may include liquids, extreme pressure solid additives, and reactive gases which are combined with a propellant gas and injected into a metered flow of charged CO2 gas-solid aerosol. Each ingredient contributes a specific physical and/or chemical dimension, including cooling capacity, penetration power, boundary layer reactivity, lubricity, viscosity, spray particle size and density. CO2 composite sprays have variable geometry including adjustable physical spray characteristics from dry to wet composition, room temperature to near-cryogenic temperature, and spray pressures ranging from 10 psi to 150 psi, or much higher if desired.

Unlike simple atmospheric gases like nitrogen and oxygen, CO2 demonstrates very strong hydrocarbon fluid and water solubility. For example, CO2 gas exhibits greater than 600% higher solubility in oils (i.e., mineral oil) as compared to compressed air. CO2 modifies lubricant and coolant MQL or flood properties to produce mixtures having lower surface tension, lower viscosity, and increased heat capacity. Moreover, CO2 itself behaves as a reactive boundary layer lubricant, forming carboxylic acid functional groups during tribochemical reactions.
CO2 composite spray technology provides infinitely adjustable cooling-lubricant compositions of CO2 coolant, propellant gases, and minimum quantities of any type of lubrication additive(s). Adjustable spray pressure, temperature, coolant particle size and lubricant additive concentration allow a machinist to customize a cooling lubricant composition for a particular machining application. One or more individually controllable machining spray applicators may also be employed.

The next blog article will cover performance aspects of CO2 composite spray technology including heat management, spray characteristics and laboratory test results.

I may be reached via e-mail at david.jackson@coolclean.com. For more information on CO2 composite spray technology, visit http://www.2cooltool.com/.

References

1. U.S. Patent No. 2,635,399, West, April 21, 1953

2. V.N. Ponduraev, Russian Eng. J., 59 (3), 1979, pp. 42-44
Study of Cubic Boron Nitride (CBN) Tools

3. W.S. Hollis, Int. J. Mach. Tool Des. Res., 1, 1961, pp. 59-78
Study of Carbide Tool

4. N.N. Zorev and N.I. Tashlitsky, Machinability, ISI Spec., Rep. 94, Iron Steel Institute, London, 1967, pp. 31-34

5. Tribology in Metalworking, Friction, Lubrication and Wear, John Schey, American Society for Metals, 1983, pp. 624-625

6. I. Ham, K.Hitomi and G.L. Thuering, Trans. ASME, 83, 1961, pp. 142-154

7. L.Walter, Can. Mach. Metalwork., 76(8), 1965, pp. 94-97

8. F.A. Monahan et al, Am. Mach., 104 (May 16), 1960, pp. 109-124