ented the use of colloidal silica as a
water-based binder for the invest-
ment casting industry. Today, the
company continues to research and
develop products that improve the
investment casting process and
enhance finished product quality.
In 2001, Nalco introduced Gray
Matter
®
, the first totally optimized
system for investment casting.
Gray Matter was designed as a
system of colloidal silica, polymers
and a pre-blended package of
refractories that complement the
qualities of each of the ingredients,
resulting in one of the strongest and
most crack-resistant shell systems
on the market.
Colloidal Silica
Nalco Company offers a line of
dedicated products for investment
casting (Table 1). In addition, Nalco
has created more products that are
unique to specific investment
casting customers or countries.
The improvements to colloidal silica
include modifications in particle
size, particle size distribution,
addition of biocide for microbio-
logical resistance and the addition
of polymers.
Particle size and particle size
distribution are important criteria
when evaluating shell strength,
rheology and slurry life. Nalco can
help supply the necessary informa-
tion in determining your needs.
Biocide is added to colloidal silica
to protect it from microbiological
contamination in the bulk tank
and in the slurry. The use of a
biocide is highly recommended
when using polymer in investment
casting slurries.
Polymer addition to investment
casting slurries is one of the most
important technical advances in
recent history. Nalco has developed
four different colloidal silica
products that have the polymer pre-
blend right from the manufacturing
plant. This allows the customer to
inventory only one product and
eliminates the need or confusion of
mixing colloidal silica and polymer
at the customer facility.
Investment Casting
Program Profile PR-236 Nalco manufactures colloidal silica
with tight control specifications,
complete MSDS information,
certificates of quality and 100%
inspection on every batch. This
assures the quality needed to keep
all investment casting foundry
processes in control.
Polymers
The addition of polymer to invest-
ment casting slurries can provide
substantial process improvements.
Polymer addition can improve
drying times, shell thickness, green
strength, shell flexibility, slurry
rheology, surface quality and
productivity.
Nalco has two polymers that
provide different characteristics to
meet your shell room needs.
LATRIX
®
6300 is a moderately stiff
polymer that creates Newtonian
fluid characteristics in the slurry.
This polymer will produce shells
that have high strength with supe-
rior surface detail. LATRIX 6300
will provide better fluidity with
Zircon primes.
LATRIX
®
6305 is an all-purpose
soft flexible polymer that provides
great adhesion while creating
thixotropic slurry characteristics.
The mildly thixotropic slurry
properties are well suited for
drainage sensitive parts and easier
to optimize for robot systems. Shells
manufactured with this polymer
have high strength and will build
thickness quicker.
Wax Cleaners
Wax preparation is an important
step in the investment casting
process. If the wax surface is not
clean, the final casting surface will
show defects. If the slurry is unable
to adhere to the wax surface, the
final casting can have lifting defects,
cracking and run-outs. A good wax
cleaner will clean the surface of the
wax, quickly drain off the wax and
slightly etch the wax surface to
provide a means of slurry adhesion.
Nalco wax cleaners fit perfectly into
any working environment where
safety, environmental and perfor-
mance are important goals. Both
products are an emulsifiable blend
designed to optimize cleaning
capabilities and product life while
helping to reduce VOCs and
personnel safety issues. The supe-
rior cleaning performance and
pleasant citrus scent make Nalco
wax cleaners a natural solution to
your wax cleaning needs.
LATRIX
®
6200 is a ready-to-use
safe wax cleaner. This neutral pH
cleaner with improved etch rates
and cleaning capability will provide
superior slurry face coat coverage.
The low VOCs and ability to flush
the rinse water down the drain will
help your foundry meet your
environmental needs.
LATRIX
®
6270 is a concentrated wax
cleaner. It is easily blended with
water and will stay in dispersion for
ease of use and easily adjusted to a
wide range of concentrations for the
desired pattern finish. This product
is formulated to resist microbio-
Table 1
Investment casting products
Part Size
Designed
Product
(nm)
%SiO
2
Biocide
Polymer
System
Prime
Backup
NALCO
®
1030
13
30
Excellent
Good
NALCO
®
1130
8
30
Good
Excellent
LATRIX
®
6010
13
30 Excellent
Good
LATRIX
®
98MD069
8
30 Good
Excellent
LATRIX
®
6009
7 to 16
30 Excellent
Excellent
LATRIX
®
6001
13
28.6
Excellent
Good
LATRIX
®
6002
13
28.6
Excellent
Good
LATRIX
®
98MD020
7 to 16
24.5
Excellent
Excellent
Gray Matter
®
8
23 NR
Excellent logical attack and to be more com-
patible with prime coat slurries.
The cleaner LATRIX 6270 emulsion
has extremely low viscosity to
allow minimal carryover, so rinse
requirements are minimized.
Chill Coating
LATRIX
®
6346 is a unique product
for the investment casting market.
When applied to the outside of
the shell, LATRIX 6346 increases
the heat emittance of the shell
surface, which helps the metal to
cool faster through radiant heat
transfer. The solidification rate of
an investment casting determines
the microstructure, strength and
quality of a cast component.
The selective application of LATRIX
6346 to specific areas of the castings
can help control shrinkage and
microstructure.
Wetting Agents, Antifoam
and Biocides
Just like a musical instrument needs
to be tuned before it can be played,
an investment casting slurry needs
to be optimized before it can be
used. Optimizing a slurry will
increase the process performance
and life of the slurry.
The addition of a wetting agent is
important to get good coverage,
adhesion to the mold and eliminate
bridging. The wetting agent will
provide process control of the
surface tension inherent in invest-
ment casting slurries. NALCO
®
8815
is a superior ionic wetting agent
that will meet most of your process
needs. NALCO
®
7510 is a non-ionic
wetting agent for more difficult
slurries.
During the slurry building process,
slurry agitation and dipping of
parts, air is continuously introduced
into a slurry. This air can trap
bubbles on the surface of the wax
or shell, which will cause metal
positives, bridging and penetration
defects. The addition of antifoam
will help to remove the air from the
slurry. NALCO
®
2305 is a water-
based antifoam that will help
eliminate these process challenges
and reduce your scrap rates.
Microbiological contamination is a
problem with slurries that are open
to the atmosphere and constantly
have parts dipped into them. When
a slurry becomes contaminated, the
pH will drop and microorganisms
will attack the organic material,
severely affecting the life of the
slurry. The addition of DURACOOL
®
6451 biocide to a slurry will prevent
growth of microbiological contami-
nation and control its spread. This
will help slurry life and also help
maintain process control of the
slurry, resulting in reduced scrap.
Refractories
In addition to colloidal silica, the
other big component used to make
investment casting shells is refrac-
tory flour and stucco. Nalco is a
distributor for Minco representing
fused silica flours and stuccos. www.nalco.com
Gray Matter, LATRIX, Nalco and DURACOOL are Trademarks of Nalco Company
©2002, 2004 Nalco Company All Rights Reserved 7-04
Our Customer Focus
and Dedication to Your
Business
Nalco surpasses the industry on
service capabilities. In addition to
on-site service, our research facility
has the ability to provide more
detailed service support. This
includes the normal day-to-day
requirements such as SiO
2
concen-
tration, polymer concentration,
microbiology testing and MOR
studies. In addition, Nalco has
in-house capabilities to do perme-
ability analysis, SEM analysis and
ICP analysis.
As a supplier, Nalco recognizes
that our customers profitability is
important for our success. That is
why the Nalco programs are built
around helping our customers
define their profit opportunities.
The Nalco Six Service Standards
help customers maintain existing
process standards while jointly
defining tomorrows needs.
Aside from our complete line of
products and services, Nalcos key
strength is our understanding of
our customers and their changing
needs. We are dedicated to enhanc-
ing our customers businesses in a
safe and environmentally conscious
manner. We measure our success
by customer retention, satisfaction,
and expansion and we strive for
continual improvement in our
people, programs and services.
To learn more about how we can
help you improve your investment
casting process, contact your
Nalco representative or our
Customer Service at:
1-800-288-0879 Voice
1-800-288-0878 Fax
Nalco Company

1601 West Diehl Road Naperville, Illinois 60563-1198
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