Feature

Managing a Surface Cleaning Facility


John Durkee, Metal Finishing columnist

John Durkee, Metal Finishing’s “Cleaning Times” columnist, offers facility managers advice on addressing challenging, real-world cleaning situations.

The manager of a surface cleaning facility faces some unique management issues.

Because cleaning work is differently-valued by enterprise management, that work has to be differently managed. This column explores some of those issues, cites some examples, and offers some remedies for managers who face these situations.

The New "Enter Here"
I visit a military base where helicopters are repaired. The work involves  more than a half-dozen stages of cleaning of mission-critical parts, before and after various repair steps. All are done within a section of the base to which this function has been assigned.

So also, it seems, has every new employee hired on the base, or every tenured employee whose "real" job has been eliminated. The result is that the crew doing cleaning work is always being newly trained.

This base has persons recognized as skilled in various crafts: welding, machining, optical inspection, etc. But  there is no ladder of professional accomplishment for those doing surface cleaning.

The manager of this shop is frustrated because she is spending too much of her resources:  training workers, reprocessing parts which fail in downstream operations, and explaining budget shortfalls.

Remedy: This manager needs support from enterprise management. She had to make her case and see that it is accepted, or move on and let someone else try to win management support.
    
Every Shift Brings a Surprise
Some metal fasteners are  produced by the cold header process, where wire is jammed through a lubricated die. The enterprise is trying to control their costs by becoming more flexible, rapidly swapping dies to make a different part. All newly formed parts are immediately fed to an aqueous immersion cleaning line to remove the lubricant.

The supervisor of the cleaning line has learned, to his sorrow, that each fastener has a  different surface configuration and size. Nozzles arranged in a fixed array, pump cleaning solution through high-velocity water jets. For some parts the arrangement impacts and flushes formed surfaces. For other fasteners, not so much.

The result is that this supervisor is responsible for an output of wildly-varying quality. Enterprise managers find costs have not been reduced, but have risen because of an increased reject rate. This supervisor's job security is in doubt.

Plainly, the cleaning line is viewed by enterprise managers as a service to the main operation. There may be added  flexibility built into the upstream capability to form fasteners, but none is added to the cleaning line at the same time.

Remedy: This supervisor needs to become part of the main operation, and know specifically how to engineer  the cleaning line to increase its flexibility. The manager in this role must become more involved.

Yet Another Surprise
When dies are swapped in the above operation to form another configuration of fastener, the lubricant is also swapped. While the aqueous cleaning chemistry was chosen in the past to remove some lubricants, it does not now remove all the lubricants being used.

This supervisor, who enjoys frequent off-plant lunch opportunities with the rep for his aqueous cleaning "juice," doesn't know why his operation is being blamed for residues left on some types of fasteners. He feels betrayed by the rep, helpless to make changes,  uncertain of his future.

Remedy: A  wise person is one who knows what they do not know. This supervisor needs a dose of wisdom   an education abut aqueous cleaning technology   instead of free lunches. This situation will never improve until enterprise management understands why this supervisor is failing and either provides him with education or replaces him with a more educated person. The fault lies upstairs!

GIGO
A client asks for help in understanding why paint was blistering on cleaned, cold-rolled steel. The defect is discontinuous in time and location on the steel. The cleaning process is simple and common:  pickling with hot  muriatic acid (HCl) later followed by a rinse with cold tap water. But the defect was proving to be costly.

First, I ask what cleaning tests are being done so we can diagnose whether the blistering is being produced by mill scale not removed by the acid treatment, flash rusting in the time between the pickling and the rinsing operations, inadequate rinsing time, hardness of the rinse water, or something else.

The answer I receive is silence. There is no testing being done.

Remedy: This one is easy. Remember the aphorism, GIGO (garbage in, garbage out)?Too many operations, IMHO, particularly aqueous cleaning operations, are operated without any proof of cleaning performance. More sites operate without testing for surface cleanliness than do so. If you don't test, you don't know anything about your operation.

Measure Twice, Cut Once
A client asks me to troubleshoot and fix a problem where deposits are periodically left on drawn wires to be used in surgical catheters.

We work together and soon find out what the deposit is: insoluble aqueous cleaning agent. The question is, why is it only intermittently present?

The answer to that question is not pleasant to the client's operation supervision. It is that their operation is out of control.

Bath temperature cycles  when steam traps dump condensate, causing the bath temperature to drop, and later  overshoot the solubility limit for the cleaning agent.

Bath solutions are replenished when operating staff thinks that a full pail of cleaning agent powder is needed to bring the bath composition "back up to full strength." Staff doesn't want to have to store and manage partial pails of powder.

In both cases measurements are routinely taken   of bath temperature  and bath composition (both vs. a minimum setpoint).

Remedy: Sometimes binary information (GO/NO GO) is not adequate. What is needed is digital numerical information, AND a control program to manage the bath so temperature and composition are always between proper limits. Just making measurements isn't enough. You have to actually take the right action based on their values.

Values
Another client  manages a suite of open-top vapor degreasers, all using a solvent with a low exposure limit. Though measurements vary, its value is essentially at the technical capability of the degreasers to contain emissions. We are asked to help modify the equipment to provide a margin of safety in controlling emissions so that the exposure limit can be met more continuously.

After some testing  we determine the equipment is neither being operated improperly nor capable of being modified to improve the control of emissions.

The outcome is twofold: our services are terminated,  testing is stopped, and  operation continues.

Basically the managers  believe there is no legal imperative to test for ambient concentrations of solvent. And they are correct    until an OSHA inspector visits and finds the measured concentrations slightly above the exposure limit, or an operator files a lawsuit claiming injury due to inhalation of excessive solvent vapor.

Remedy: To have a remedy, there must be a problem. Certainly, there is no legal problem. It is a personal situation (not a problem) to challenge that decision. I can't.

Summary
In addition to the skills needed and problems faced by a traditional process manager, one who is managing a cleaning line faces special challenges. But the skills needed to solve them should be manifested by any good  manager and found in any well-managed enterprise.
    
BIO
John Durkee is the author of the book Management of Industrial Cleaning Technology and Processes, published by Elsevier (ISBN 0-0804-48887). In 2012, Elsevier will publish in print his two landmark books Cleaning with Solvents - Science and Technology [ISBN 9781455731312], and Handbook of Cleaning Solvents, as well as a 4-part e-Book, Design of Solvent Cleaning Equipment. He is an independent consultant specializing in metal and critical cleaning. You can contact him at PO Box 847, Hunt, TX 78024 or 122 Ridge Road West, Hunt, TX 78024; 830-238-7610; Fax 612-677-3170; or jdurkee@precisioncleaning.com.

 

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Cleaning, Pretreatment & Surface Preparation  •  Defense & Military  •  Environmental & Regulatory Compliance

 

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