bfksolutions.com

Metal cleaning is an aspect of manufacturing that is too-often overlooked – until a problem occurs or until a small process problem gets out of control and the failure rate explodes to non-competitive levels.   

BFK Solutions assesses your entire process flow, including initial cleaning after forging, forming, and machining.  We look at the soils, the product mix, the cleaning agents, and the cleaning equipment.  We determine if cleaning is needed.  We look at specifications and process documentation. Even more important, we also work with your employees to determine what is actually happening.  If a big process change with a significant investment is needed, we identify your best choices in cleaning agent and cleaning equipment. 

Then, we make sure you get what you need, make sure you get what you pay for, and make sure the process runs smoothly. 

Your process and requirements are unique.  Contact us; we’d be pleased to discuss how to make your cleaning process more productive, how to improve your competitive stance. 

Troubleshooting, Cleaning Processes for Medical Products

The client had an unacceptable failure rate for high value, non-implantable medical products that contained tungsten and other metals.  The failure rate had jumped from miniscule to the mid-double digits. There were problems with the cleaning equipment and with overall process control.  Given the economic situation, there had been a significant exit of knowledgeable employees. Many of those remaining were mystified by the concept of critical cleaning and terrified of making a career-stopping process change. 

BFK Solutions conducted a comprehensive site visit and educational program.  We tracked process flow starting with initial metal forging and forming through final cleaning.  Most of the industrial and precision/critical cleaning processes were aqueous-based.  Some of the cleaning processes that took place at initial stages of forming and fabrication were archaic, ineffective, and could contribute to contamination. We suggested better equipment.  We provided modifications to the intermediate batch processes to provide more effective rinsing.  We determined that one significant problem was that the equipment for a high-volume precision cleaning process had been improperly reconfigured. This resulted in exceedingly high-foaming of the cleaning agent and inadequate rinsing.  We worked with the equipment vendor to adapt current but usable equipment.  We determined that many of the employees assigned to the project had little experience in industrial or critical cleaning.  We therefore supplemented our formal educational program with one-on-one interaction with key employees.  This provided them with the knowledge, confidence, and general “street smarts” they needed to evaluate claims made by cleaning agent and cleaning equipment vendors.  The company was able to move forward in correcting the problem.

Discoloration After Phosphatizing

A producer of consumer products developed a sudden, acute problem with discoloration of the product after phosphatizing. The plant was in a rural area; the problem showed up in late summer.  BFK Solutions resolved the problem by working with the client and the supplier of process chemicals. 

BFK Solutions found two relatively quick and low-cost solutions.  The first was to improve the water quality. The chemical supplier had recommended use of tap water.  It turned out that the tap water had changed in quality; this appeared to be correlated with agricultural activities.  While deionized water would have been overkill, adding a simple water purification system and cleaning out the cleaning system resolved the problem. The second solution was to do a general overhaul of the cleaning system. The primary cleaning system was overdue for general maintenance and cleanout.  

Bearings – Seismic Protection

Because we typically work with miniature bearings, we were somewhat surprised to find a facility with seismic protection bearings, some weighing thousands of pounds, in various stages of assembly.  Seismic bearings allow structures to roll with the punches. The basic cleaning process was set in stone, because it had been accepted by the pertinent governmental agencies involved in building and highway safety.  

One immediately apparent problem was that the technician involved in cleaning had to maneuver the parts into a large vapor degreaser full of an aggressive solvent.  There was considerable splashing of solvent; and maintaining a vapor blanket was impossible.  To resolve the potential employee and environmental problems, we immediately arranged to have automated parts handling equipment installed.  This contributed to the comfort and safety of employees and decreased solvent loss.  

However, there was also the issue of environmental management of an  inherently emissive solvent.  The combination of Federal and local restrictions put the company in a “Catch 22” situation.  This gets into an area we euphemistically term  “Regulatory Facilitation.”  We worked with local and Federal environmental agencies; we explained the situation, including the public safety hazards inherent in poorly-cleaned bearings.  BFK Solutions was able to resolve the situation.  The company successfully manufactured product.

Surface Preparation for Engineered Coatings

This study illustrates how perchloroethylene (PCE) can be used for metal cleaning, with negligible worker  and community exposure. While PCE is a very effective, aggressive, high-wetting, and low-residue cleaning agent, it is an air toxic with an unfavorable worker exposure profile.  How do you use it effectively and safely?  With careful equipment selection and good process development, the client continues to use the cleaning agent that they have found optimal in the South Coast Air Quality Management District (SCAQMD), an area with exceedingly stringent regulations covering air emissions.

The bottom line: Annual PCE emissions have been dramatically reduced.  The system is well accepted by employees.  High quality coated products are being produced. The customers are satisfied with product quality.

Annual PCE Emissions to Air, Airless System

Plasma Technology Incorporated, headquartered in Torrance, CA, specializes in application of engineered coatings using plasma vapor deposition, physical vapor deposition, and ion vapor deposition.

The facility is a very specialized job shop with critical requirements for precision cleaning, surface preparation, and product performance. Products include bearings, aircraft engines, canning chucks, and an array of other aircraft and consumer products. Substrates include stainless steel, aluminum, magnesium, and a number of alloys.  Soils include an assortment of organic oils, water-soluble oils, and fingerprints. Levels and mixtures of soils are variable. While some components could be cleaned with aqueous processes; others require solvent cleaning. The company had been using vapor phase cleaning in perchloroethylene. While their open-top cleaning system provided good solvent containment, stringent local environmental constraints precluded use of chlorinated solvents or of VOC’s (volatile organic compounds).

The company considered several airless vacuum systems as well as a flammable (low flashpoint) solvent system using acetone. Acetone could have been an economical, VOC-exempt option. However, substrate compatibility issues preclude the use of heated acetone for this particular application. Four airless solvent systems were evaluated in terms of performance, flexibility to meet the diverse product line, reliability, and cost. 

A custom system including vapor phase, spray, and immersion cleaning with ultrasonics was selected. During initial installation and process optimization, BFK Solutions assisted in troubleshooting filtration issues and in working with the equipment vendor to make appropriate equipment modifications.

The system is now in routine use. There has been good customer and employee acceptance, the process runs smoothly with miniscule release of solvent to the air.  

References, Engineered Coatings:

“Clean Critically: An Overview of Cleaning Applications,” B. Kanegsberg Chapter 15 in the second edition of Handbook for Critical Cleaning, Applications, Processes and Controls (Volume 2),  p. 197, CRC/Taylor & Francis, 2011. 

“Cost-Effective cleaning for quality thermal spray coating,” B. Kanegsberg, invited presentation, International Thermal Spray Association, Fairport Harbor, OH, 2009. 

“Compliance and Performance: Selecting and Optimizing a Contained Cleaning System,” B. Kanegsberg, R. Dowell, S. Norris, and J. Unmack,” invited presentation, International Thermal Spray Association, Las Vegas, NV, October 31, 2003.