Originally published in
the July/August 2013 issue of metal
finishing magazine (p. 20-21)
DORIS SHCHULZ, OWNER, SCHULZ PRESSE TEXT, STUTTGART, GERMANY
Leaner, Greener Cleaning
= Measurable Results
Products LLC makes switch from nitric acid dip cleaning to closed-loop solvent
Making the change from a nitric acid aqua-based cleaning
machine to a closed-loop solvent system has paid off for Superior Products,
LLC. The Cleveland, Ohio-based company reduced the water consumption annually
from 2 million gallons to zero, dropped labor for cleaning, and achieved better
overall cleaning results in the process.
Superior Products, LLC
started in 1946 as a general screw machine company and has grown its product
lines to serve the welding, medical, beverage, cryogenic liquid and specialty
gas industries worldwide with fittings, manifolds and assemblies. The company’s
product range includes about 3,000 unique parts, which are developed and
manufactured at the facility. Superior machines 10 to 15 million pieces
annually which are primarily made of brass and stainless steel.
After machining, the
parts are contaminated with chips and swarf as well as cutting fluids and oils.
As they are used in connection with compressed gas in industrial, medical, and
specialty gas applications, the parts have to be cleaned to an “oxygen clean” standard.
The Compressed Gas Association (CGA) allows no more than 47.5 mg/sq.ft. of
organic material on the parts. “If a dirty part isused in an oxygen system,
there is a chance of fire because it is compressed gas that can lead to
explosion,” Superior Products general manager Iain Hodgekins explained.
Superior’s previous cleaning solution, a nitric acid bright dip cleaning system,
reached a level of about 17 or 18 mg/sq.ft and thus satisfied the cleanliness
requirement. However, the cleaning system was about 30 years old, and many
parts had to be re-cleaned. Additionally, the system used about two million
gallons of water annually that had to be processed for heavy metals in the
“We wanted a modern system that would
allow us to drastically reduce the impact on the environment,” Hodgekins
recalled. “Furthermore, we wanted a more reliable cleaning process that would
require less re-cleaning and improve our efficiency and quality.”
For selecting the appropriate
cleaning solution, Superior Products evaluated available cleaning procedures —
from aqueous methods to solvent-based techniques — and talked to several
cleaning machine manufacturers. Based on cleaning tests conducted at Dürr
Ecoclean’s facility in Wixom, Mich., the company decided on the Universal 81C.
This is a single chamber, solvent-based, closed-loop cleaning system that uses
no-chlorinated hydrocarbons. The fact that it operates completely under vacuum
negates the need for additional explosion protection when using combustible
solvents such as isoparaffinic hydrocarbons. Additionally, the machine offers
multiple monitoring of safety-relevant temperatures and pressures.
“With this closed-loop system we have
achieved excellent cleaning results, we don’t need water for cleaning, and we
have no wastewater management issues,” Hodgekins said. The old system, he
noted, required two operators for eight hours a day to clean parts. Due to the
fully automatic cleaning process with the Universal 81C, the manual labor for
cleaning has dropped to one hour per day. “We save the equivalent of 15 hours’
work each day.”
design feature of the Universal 81C is the machine’s ability to store eight
freely programmable and selectable cleaning programs in its controller. The
parameters include rotating and swiveling movements in the work chamber during
cleaning and drying, temperature settings, ultrasonic characteristics, and IFW
settings. In this way, the cleaning treatment can be customized to every part
currently using three programs, and we are very satisfied with the cleaning
results,” Hodgekins stated. “There are no parts that need to be re-cleaned, and
the cleaned parts surfaces show a rest-level of organic materials of only 5 to
6 mg/sq.ft. Compared with our old system’s results, contamination has dropped
by two thirds. This gives us very good peace of mind knowing that the machine
is cleaning well above the standard.”
plus: the vacuum drying technique ensures that even parts with a complex
geometry – e.g., bores, blind holes and undercuts – emerge from the process
fully dried. The fully automatic vacuum
distillation unit as well as full-flow and bypass filtration, which come as
standard, remove oil and grease, chips, and swarf from the solvent on a
continuous basis. As a result of these features, the cleaning fluid has a long
batches get transported into the machine’s cleaning chamber by an automatic
conveyor feeding system, which is equipped with a proximity sensor that
identifies the parts and chooses the appropriate cleaning program
automatically. Depending on the program, the cleaning cycle takes between 8.5
and 9 minutes to complete.
only can we put anybody on the cleaning machine and they will do a good job,
but the proximity sensor also saves a lot of manual labor,” Hodgekins stated.
And that translates into something that’s priceless for the general manager:
peace of mind.
For more information on Dürr Ecoclean,
Inc., please call (248) 560-2100 or visit www.durr-ecoclean.com.
Products, LLC can be reached at (216) 651-9400 or at www.superiorprod.com.