
I had the
opportunity to Interview Dale Wolford, founder
of A & D Rubber Products, Inc., (http://www.adrubber.com) regarding
his
past 3 years using SUPER-WATER®. Dale has been in business since
1991, in the
waterjet industry since 1997(?), and since the year 2000 has been using
SUPER-WATER® to enhance his cutting speeds and reduce his spare
parts cost on
his two machines. A & D Rubber
Products
supplies to companies primarily in the aerospace, electronic and
transportation
industries. They primarily use their abrasive waterjets to cut rubber
products,
but also do work in other materials such as glass and metal. What follows are some miscellaneous notes
from our conversation.
Dale
says that he typically runs at 55,000 PSI (3800 Bar)
through a 0.011" (0.28mm) jewel with 0.5 Lb/min (0.23 Kg/min) abrasive
flow rate. He uses a 0.2% solution of SUPER-WATER®.
Performance
is good.
According to Dale, he is happy to see a significant reduction of
spare
parts costs, as well as improved cutting performance for some of his
key
materials (Mostly rubber).
Installing
the system for the first time on a machine
requires completely flushing the system using the SUPER-WATER® for
10-12
hours. Failure to do this will cause all
sorts of accumulated minerals and debris in the high-pressure plumbing
to break
free, and plug jewels in the nozzles.
Dale has two systems. On his
first system he did not flush the system, and had all sorts of troubles
with
plugs on the first few days of use. On
his second system, he flushed it thoroughly, and had no troubles with
debris at
all.
Dale goes on to say also that it is hard to "dial it
in" at first, but once it is dialed in, it works great from then on.
Most
of what Dale cuts is 2" (50mm) thick 60-80
Durometer rubber which he cuts using abrasive.
He says that without SUPER-WATER® he cuts at approximately 1
inch per
minute (50 mm/min). Using SUPER-WATER®
he is able to make the same finish cut at 3-4 inches per minute
(150-200 mm/min).
For
cutting Glass, he says he gets significantly better
finish, and that where there would be striation marks before, he now
has none.
("Striation marks" essentially means "rough edges")
For
cutting metals, he says the results are hard to tell,
but seems to be a little better than without SUPER-WATER®
Dale
says that by far the biggest benefit of SUPER-WATER®
is the fantastic reduction in spare parts usage and increase in seal
life on
his pumps.
Dale
says that prior to using SUPER-WATER® he was getting
250 to 300 hours on his intensifier style pumps. Afterwards,
he says the seal life jumped to
over 1500 hours, and has lasted as long as 1900 hours.
He changes his seals as preventative
maintenance now at 1500 hours, simply because he does not want to risk
damaging
other components if he lets the seals run all the way until they cause
problems.
Overall,
he says that his parts costs have dropped in
half.
I
asked him if this is due to other factors such as newer
seal designs, or something else. He
believes that this is not the case because the general conditions that
he runs
under have otherwise not changed.
Dale
says, "The maintenance improvements are what
stand out over everything".
He
said that it has not been a problem for him. Spilling
pure SUPER-WATER® is a slipping
hazard, and it can make a mess, but if you spill the diluted 0.2%
solution, it
is no problem at all, and does not really pose any more of a slipping
hazard
than plain water. (Dale says that he is used to working with polymers
for other
reasons, though, so it is nothing new to him in this regard.)
According
to at least one user, SUPER-WATER® is a bit
awkward to setup at first, and is a little awkward to handle, but the
increases
in cutting speed, and significant savings in spare parts usage make it
well
worth using.
Special
thanks to Dale Wolford of A & D Rubber
Products for sharing his experiences!
If
you have experience with SUPER-WATER®, whether good or
bad, I would like to hear from you as well, so I can post your comments
to this
web site. If you are interested, click here.
Special
thanks to Renato Lombari for the following notes:
I
have worked with ultra-high
pressure waterjets, operating up to 55,000 psi, for 14 years and
SUPER-WATER®
for 9 years. This includes:
-
plain water
- plain water + SUPER-WATER®
- plain water + abrasive
- plain water + SUPER-WATER® + abrasive
My
work, during this time, gives an unambiguous
demonstration of the economic advantages of using Super-Water®
(1,2,3) .
Relative to plain water, the addition of SUPER-WATER® to a
ultra-high pressure
waterjet cutting system:
-
improves the quality of cut (6) (An excellent
example of this enhanced quality was published by Weber (1997).
- increases cutting speeds by 30% - 200% (non-abrasive cutting system)
- reduces intensifier operating and maintenance costs by 38%
(non-abrasive cutting
system) [from $11.12/ hr (1993) to $ 6.86/ hr (1996) = $4.26/ hr
reduction]
These
results were for cutting fiberglass
acoustical panels using an intensifier. My results also
parallel those previously published for precision cutting of natural-,
synthetic-, silicone-, and foam-rubber (4) as well as synthetic
materials such
as Vistanex (5) and shoe soles (4).
Currently,
at Soheil Mosun Limited, we use
SUPER-WATER® 100% of the time. Waste water and abrasive is disposed
of without
any problems. We typically cut the following materials:
-
304, 316 stainless steel
- duplex stainless steel
- aluminum (various alloys)
- titanium
- brass (various alloys)
- clear float glass
- laminated glass
- slate
- blue tempered steel
- hot and cold rolled steel
- marble and granite
- acrylic
- ultra-high molecular weight polyethylene
- plywood, MDF and particle board
For
a detailed analysis of abrasive cutting speeds
and cut surface quality please see the SUPER-WATER®
groups file named "Reduction
in Abrasive Consumption.doc" posted 04/21/2002.
I've
found that an approximate 0.1% to 0.2% S-W ®
solution produces the following three-fold effects:
-
reduces flow resistance due to substantial drag
reduction. Hoyt (1986) produced laboratory turbulent rheometer findings
showing
that even 9 ppm S-W ® resulted in a 20% drag reduction and Cobb and
Zublin
(1985) obtained a drag reduction of 54% in 2187 meters of 2.16 cm
(0.85")
id coiled tubing.
- collimates the jet leaving the nozzle
- introduces macromolecular bombardment (Kudin et al., 1973) of polymer
molecules dissolved in the water
REFERENCES
1.
R. Lombari, “Ultra-High Pressure Non-Abrasive
Polymer Jetting: A Production Environment Implementation”, Proceedings
of the
9th American Waterjet Conference (Dearborn, Michigan: August 23-26,
1997),
Paper 17, pp. 251-266.
2.
R. Lombari, “Cutting Fiberglass Acoustical
Panels”, Jet News,* December 1995, p. 7.
3.
R. Lombari, letter to the Editor, ... “the
longevity of our consumable jet components due to the lubricity of
SUPER-WATER®”, Jet News,* November 1996, pp. 2 an 11.
4.
W.G. Howells, “Polymerblasting with SUPER-WATER®
from 1974-1989: a Review”, International Journal of Water Jet
Technology,
Volume 1, Number 1, (March 1990), pp. 1-16.
5.
W.G. Howells, “Additive Improves Abrasive Jet
Cutting”, Jet News,* December 1995, pp. 5 and 10.
6.
D. Weber, letter to the Editor, Jet News,*
February 1997, p. 12.
*
Jet News is a bimonthly publication of the
Waterjet Technology Association, St.
Louis, Missouri.
For
more information on A & D Rubber Products, visit: www.adrubber.com
