U.S. patent application number 17/303690 was filed with the patent office on 2021-12-23 for aircraft fluid resistant sealant for use on aircraft parts.
The applicant listed for this patent is THE PATENT WELL LLC. Invention is credited to Kent Boomer, Matt Boyd, Jeff Busby, Mike Dry, Chad Knight, Peter Sibello.
Application Number | 20210395564 17/303690 |
Document ID | / |
Family ID | 1000005825942 |
Filed Date | 2021-12-23 |
United States Patent
Application |
20210395564 |
Kind Code |
A1 |
Busby; Jeff ; et
al. |
December 23, 2021 |
AIRCRAFT FLUID RESISTANT SEALANT FOR USE ON AIRCRAFT PARTS
Abstract
A number of sealants are provided that are resistant to
degradation by aircraft fluids. In some embodiments, the sealants
are resistant to degradation by Jet A fluid and at least one of the
three types of hydraulic fluids typically used in aircraft. These
embodiments are also typically cure in place from a two-part
polyurethane or polyurea mix, with cure to a visibly clear coating.
In some embodiments, they may be sprayed on an aircraft surface or
applied by hand (brush or injectable). In other of these
embodiments, the sealants comprise, at least in part, a cured,
soft, tacky polyurethane gel that is resistant to at least one of a
synthetic hydrocarbon based or mineral oil based hydraulic
fluid.
Inventors: |
Busby; Jeff; (Millsap,
TX) ; Dry; Mike; (Fort Worth, TX) ; Boomer;
Kent; (Aledo, TX) ; Boyd; Matt; (Fort Worth,
TX) ; Knight; Chad; (Dodd City, TX) ; Sibello;
Peter; (Fort Worth, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
THE PATENT WELL LLC |
FORT WORTH |
TX |
US |
|
|
Family ID: |
1000005825942 |
Appl. No.: |
17/303690 |
Filed: |
June 4, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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16021391 |
Jun 28, 2018 |
11059991 |
|
|
17303690 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16J 15/102 20130101;
F16J 15/14 20130101; H02G 15/013 20130101; B05B 7/2472 20130101;
C09D 175/04 20130101; C09D 175/02 20130101; F16J 15/104 20130101;
B64D 37/32 20130101; B05B 7/0408 20130101; B64D 37/06 20130101;
B64F 5/10 20170101; B05B 11/0054 20130101; B64D 2045/009 20130101;
B64D 45/00 20130101; C08G 2190/00 20130101; B64F 5/45 20170101;
B05B 7/26 20130101 |
International
Class: |
C09D 175/04 20060101
C09D175/04; F16J 15/10 20060101 F16J015/10; B64D 45/00 20060101
B64D045/00; B64D 37/32 20060101 B64D037/32; H02G 15/013 20060101
H02G015/013; B05B 11/00 20060101 B05B011/00; B05B 7/26 20060101
B05B007/26; B64F 5/10 20060101 B64F005/10; B64F 5/45 20060101
B64F005/45; F16J 15/14 20060101 F16J015/14; B05B 7/24 20060101
B05B007/24 |
Claims
1. An injector assembly having: a body with a first compartment
with a first fluid and a second compartment with a second fluid; a
forcing element engaging the first and second compartments; a
mixing straw in fluid communication with first and second
compartments and capable of mixing the fluids and emitting the mix
from a tip at the removed end thereof when a force is applied to
the forcing elements; wherein the mix, upon cure, is a polymer mix
that is resistant to degradation upon exposure to Jet A Fuel.
2. The injector assembly of claim 1 wherein the mix, upon cure, is
also resistant to degradation upon exposure to a phosphate ester
based hydraulic fluid.
3. The injector assembly of claim 2 wherein the mix, upon cure, is
clear.
4. The injector assembly of claim 2 wherein the mix, upon cure, has
an elasticity of at least 125%.
5. The injector assembly of claim 2 wherein the mix, upon cure,
cures to a hardness of 85% or more of final hardness in 24 hours or
less.
6. The injector assembly of claim 2 wherein the mix, upon cure, is
elastomeric.
7. The injector assembly of claim 2 wherein the mix, upon cure, has
a peel strength of 1-10 piw (90.degree., bare aluminum)
8. The injector assembly of claim 2 wherein the mix, upon cure, has
a hardness of between 20-80 Shore A.
9. The injector assembly of claim 2 wherein the mix, upon cure, has
a tensile strength greater than 100 psi (ASTMD 412).
10. The injector assembly of claim 2 wherein the mix, upon cure,
passes the 3000 hour salt fog (ASTM B117).
11. An injector assembly having: a body with a first compartment
with a first fluid and a second compartment with a second fluid; a
forcing element engaging the first and second compartments; a
mixing straw in fluid communication with first and second
compartments and capable of mixing the fluids and emitting the mix
from a tip at the removed end thereof when a force is applied to
the forcing elements; wherein the mix, upon cure, is a polymer mix
that is resistant to degradation upon exposure to Jet A Fuel;
wherein the mix, upon cure, is also resistant to degradation upon
exposure to a phosphate ester based hydraulic fluid; wherein the
mix, upon cure, cures to a hardness of 85% or more of final
hardness in 24 hours or less; wherein the mix, upon cure, is
elastomeric.
12. The injector assembly of claim 11 wherein the mix, upon cure,
has a hardness of between 20-80 Shore A.
13. The injector assembly of claim 11 wherein the mix, upon cure,
has a tensile strength greater than 100 psi (ASTMD 412).
14. The injector assembly of claim 11 wherein the mix, upon cure,
passes the 3000 hour salt fog (ASTM B117).
Description
[0001] This application is a continuation of, and claims the
benefit of, pending application Ser. No. 16/021,391, filed Jun. 28,
2018, which, in turn, claims the benefit of and priority to
provisional application No. 62/526,248, filed Jun. 28, 2017 and
incorporates by reference US Application Publication No.
2014/0167367, published Jun. 19, 2014; Publication No.
2016/0208919, published Jul. 21, 2016, Publication No,
2015/0069722, published Mar. 12, 2015; and U.S. Pat. Nos.
6,530,577; 6,695,320; and 7,229,516. This patent also incorporates
Publication No. 2017/0282196, published Oct. 5, 2017.
FIELD OF THE INVENTION
[0002] A number of sealants are provided that are resistant to
degradation by aircraft fluids. In some embodiments, the sealants
are resistant to degradation by Jet A fluid and at least one of the
three types of hydraulic fluids typically used in aircraft. These
embodiments are also typically cure in place from a two part
polyurethane or polyurea mix, with cure to a visibly clear coating.
In some embodiments, they may be sprayed on an aircraft surface or
applied by hand (brush or injectable). In other of these
embodiments, the sealants comprise, at least in part, a cured,
soft, tacky polyurethane gel that is resistant to at least one of a
synthetic hydrocarbon based or mineral oil based hydraulic
fluid.
[0003] Sealants for aircraft parts, in some embodiments, the
sealants comprising, at least in part, a two-part cured
polyurethane or polyurea that is resistant to degradation from
exposure to common aircraft fluids. The sealant may include a
gasket or tape having a skeleton or carrier, the gasket or tape
being aircraft fluid resistant. The sealant may be a sprayable
sealant that is aircraft fluid resistant. The sealant may also
include a sprayable sealant that is mixed and immediately applied
to an aircraft surface, a surface into which it cures rapidly to
form a clear sealant. The sealant may also be an injectable
sealant.
BACKGROUND OF THE INVENTION
[0004] Current problems with some aircraft sealants include their
inability to avoid degradation and loss of properties when exposed
to certain fluids common to an aircraft. These fluids include
hydraulic fluids and aircraft fuel such as Jet A fuel. Some of
these fuels may not only degrade sealants, but may also be
flammable, in which case, a sealant that lacks or impedes
flammability is beneficial. Other problems in aircraft sealants is
their long cure time when being applied at room temperature. For
example, one sprayable polyurethane coating used as a sealant on an
aircraft fuel tank exterior has a cure time of 7 days at 77.degree.
F., at 50% relative humidity. Some sealant applications require, or
at least would benefit from, a faster cure time. Other problems
with some aircraft sealants is opacity, which may prevent a visual
inspection of deterioration beneath the sealant, that is
deterioration of the surface onto which the sealant is applied.
Other problems with sealants is that they are often not easily
removable, for example, for a replacement. Sealants are sometimes
too rigid, having not enough elasticity for joints in aircraft,
which may require some movement. Because of the myriad of
requirements for aircraft sealants, and the harsh environment to
which they are typically exposed, it is not surprising that the
discovery of good sealants is a difficult endeavor
SUMMARY OF THE INVENTION
[0005] A sealant is a material used for sealing something and
blocking passages or contact of fluids and/or gases with a sealed
surface. They may have a number of different physical and chemical
properties, work in a number of different environments in different
ways, and come in a number of different structures for application
to a variety of aircraft parts.
[0006] A sprayable sealant is a sealant that is applied with a
spray gun having a sealant bearing cartridge that emits an atomized
spray comprising thousands of tiny droplets of, typically, an
uncured mix that will cure on the targeted surface to form a
sealant coating.
[0007] A gasket is a sealant used to seal a joint or junction
typically comprising two surfaces which may be under
compression.
[0008] An injectable sealant is one which is manually applied from
an injector assembly typically as a thick, flowable, viscous,
uncured mix which will cure to form an injected sealant coating on,
in or around a surface. The injectable sealant may be a two-part
mix that is mixed upon application, typically from a mixing straw
of the injector assembly and may be used in potting and
encapsulation of materials.
[0009] A sealant tape is a sealant that has a length and width many
times its thickness and may be used as a gasket, or a sealant wrap
when used to wrap around the outside of a cable or junction, such
as an electrical cable or an electrical junction.
[0010] Applicant has found that removability, as measured by peel
strength is an important parameter in aircraft sealant applications
including those set forth in these specifications. Applicant also
has found that elasticity (that is, being elastomeric) as a measure
of workability is important in aircraft sealant applications.
Applicant has further found that tensile strength is important for
toughness, especially in the environments set forth herein. The
workability, toughness, and removability are important within
ranges, in some embodiments, the sealants disclosed herein are
found to be within the following ranges: peel strength 1-10 piw
(90.degree. peel back, bare aluminum alloy); at least elasticity
125-200%; tensile strength greater than 100 psi (ASTM 8 412 "dog
bone"). The sealants disclosed herein when used as injectables,
sprayables, gaskets or tapes provide the toughness, workability and
removability and also are optically clear and cure quickly at room
temperature. Rapid cure means cure to about at least 85% final
hardness in 24 hours or less, 77.degree. 50% RH. Full hardness is
between 20-80 Shore A. As disclosed herein, the embodiments pass a
salt fog test to demonstrate their environmental resistance.
Another characteristic, important for aircraft environments, is
durability--the importance of maintaining these characteristics
over wide temperature and pressure cycles to which aircraft are
often exposed. When combined with fluid resistance as set forth
herein, the sealants provide a number of improvements over prior
art sealants.
[0011] The sealant may, in some embodiments, be visibly clear.
Visible clarity means placing four 50 AWG tungsten wires
(lengths=0.2 inch, 0.5 inch, 1 inch, 1.5 inch) on a test panel and
coating the panel with the sealant about 0.040'' thick. After cure,
one may visually examine (assuming 20/20 vision) to determine the
minimum length of wire that is visible from about 5-6 feet away
under normal lab light conditions (100 to 1000 lumens). The
shortest wire should be visible. Applicant's coating as set forth
should pass at least this test, and passing this test refers to
visible clarity or visually clear. In some embodiments, Applicant's
mix may pass this test immediately upon application and through to
full cure.
[0012] The sealant is preferably elastomeric (that is, elastic).
Elastomeric means a 1/16''.times.1''.times.3'' cured piece of
sealant may be stretched to at least 130% its length and quickly
recover to about its original length.
[0013] In some embodiments, applicant's sealant is resistant to at
least one of a phosphate ester based hydraulic fluid, a
mineral-based hydraulic fluid or a synthetic hydrocarbon based
hydraulic fluid and also resistant to Jet A fuel. Jet A fuel
resistance means a maximum weight change of plus or minus 1% (or in
an alternate range .+-.4%, or in another alternate range .+-.8%),
after 24 hours, submersion test. In the claims, Jet A fuel
resistant means the broadest of these ranges unless a specific
range is stated. Phosphate ester based fluid resistance means a
maximum weight change of plus or minus 7% (or in an alternate range
12%, or in another alternate range 18%) over 24 hours, submersion
test. In the claims, phosphate ester based hydraulic fluid
resistance means the broadest of these ranges unless a specific
range is stated. Mineral oil-based hydraulic and synthetic
hydrocarbon-based hydraulic fluid resistance means a maximum weight
change of plus or minus 1% (or in an alternate range .+-.5%, or in
anther alternate range .+-.10%) after 24 hours, submersion test. In
the claims, mineral oil-based and synthetic hydrocarbon based
hydraulic fluid resistance means the broadest of these ranges
unless a specific range is stated.
[0014] Skydrol.RTM. LD-4 is a fire resistant aircraft hydraulic
fluid that is well known and used around the world Skydrol.RTM. is
a phosphate ester based hydraulic fluid. AeroShell 31 is a
synthetic hydrocarbon-based hydraulic fluid (Mil-H-83282) and Mobil
Aero HF is a mineral-based hydraulic fluid (Mil-H-5606). These
fluids are incompatible with many adhesives and sealants.
[0015] The materials and components used in and near any aircraft
hydraulic and/or fuel system are carefully selected by the aircraft
manufacturer. Materials used in conjunction with hydraulic fluids
and Jet A fuel should withstand exposure to these fluids with
minimum swell and minimum or no loss of integrity. The term "Jet A"
is intended to cover all Jet A type fuels. such as JP4, JPS, Jet
A-1, and the like. Jet A fuel is manufactured to international
standards.
[0016] The sealants Applicant discloses herein are not in the
nature of permanent bond adhesives, rather they are sealants which
allow removability. Permanent bond adhesives usually dry hard and
need to be scraped off of the surfaces to which they adhere. The
sealant's strength characteristics--adhesion--are less important
than its flexibility and ability to withstand joint movement and
maintain some adhesion sufficient to provide a moisture proof seal
and corrosion resistance. Removability with toughness allows the
sealant to be removed as a sheet or otherwise maintain its
structural integrity when removed.
[0017] Embodiments of a sealant are disclosed for use in providing
corrosion resistance on an aircraft part, the tough, removable,
workable sealant comprising: a gasket having a cured polymer body
comprising a non-foam, cured polyurethane and a skeleton having
openings; wherein the skeleton is encapsulated in the body in an
uncompressed condition; and wherein at least part of the body is
aircraft fluid resistant polyurethane resistant to both Jet A and a
phosphate ester hydraulic fluid. The cured polyurethane body
sometimes includes a perimeter portion and a non-perimeter portion
which is aircraft fluid resistant polyurethane. The non-perimeter
portion may be a cured, tacky, soft polyurethane gel. The perimeter
portion may be aircraft fluid resistant polyurethane.
[0018] Embodiments of a sealant are disclosed, used in a
two-compartment cartridge assembly for applying a tough, removable,
workable aircraft fluid resistant spray on sealant coating, the
cartridge assembly for use in a pneumatic mix and spray gun, the
cartridge assembly comprising: a body having a first compartment
and a second compartment, the first compartment containing a first,
polyol part of a sealant mix, the second compartment containing a
second, isocyanate part of the sealant mix. The body is dimensioned
to engage the mix and spray gun, the body also has a receiving port
for receiving compressed gas to drive the mix. A mixing straw is
engaged to the two compartments, and configured to receive and
combine the two parts and emit the sealant mix, under pressure,
from a tip at a removed end thereof to form a cure in place
aircraft fluid resistant polyurethane sealant coating on a
workpiece. The sealant coating may be clear up to about 250 mil
thickness to see any underlying cracks in the workpiece. The
sealing coating may be IOC and solvent free. The sealant coating
may gel on the workpiece in under about 30 minutes. The sealant
coating may reach a cured hardness (about 85% or greater of final
hardness) between about 20-80 Shore "A" at 77.degree. F. in about
24 hours or less (50% relative humidity). The sealant coating may
be between about 3 to 30 mil thick on a workpiece. The viscosity of
the sealant mix prior to gelling may be between about 700 and 1200
cps. The mixing straw may be disengageable from the body so as to
be replaced if it clogs with gelled or cured mix. The sealant
coating may be Flame Retardant under 14 CFR 25.853a, Appendix F,
Part 1(A)(1)(ii) (12 second vertical burn). The sealant coating
displays good cohesion to the workpiece and may be flame retardant
and UV resistant.
[0019] A method is provided for coating an aircraft part with a
tough, removable, workable sealant, comprising the steps of:
providing a pneumatic, mix and spray gun with a mixing straw and
two chambers, a first chamber having a first mix component and a
separate second chamber having a second mix component, the mix and
spray gun configured to mix the two components in a nozzle and emit
a spray of atomized. uncured mix from a tip of the mixing nozzle;
first applying to a first section of a first workpiece a first
layer of uncured mix; and allowing the uncured mix to cure to form
an aircraft fluid resistant polyurethane sealant coating.
[0020] Embodiments of a sealant are disclosed wherein a cartridge
assembly is provided for manually injecting a tough, removable,
workable aircraft fluid resistant injectable sealant on an aircraft
surface. The cartridge assembly includes a body having a first
compartment and a second compartment, the first compartment
containing a resin and the second compartment, a hardener. A
forcing element for engages the two compartments. A mixing straw
engaging the body and two compartments. The mixing straw has a tip
for emitting an uncured sealant mix when force is applied to the
forcing element. The uncured mix will cure to a sealant which is
resistant at least one of a phosphate ester based hydraulic fluid
or a synthetic hydrocarbon based hydraulic fluid and also resistant
to Jet A fuel.
[0021] Embodiments of a sealant are disclosed, namely, a tape is
provided for use as a tough, removable, workable, aircraft fluid
resistant sealant. The tape may comprise a stretchable foam carrier
and a cured, non-adhesive polymer body some of which is in contact
with the carrier and on an outer surface thereof, the cured,
non-adhesive polymer sealant being fluid resistant to at least one
of a phosphate ester based hydraulic fluid or a synthetic
hydrocarbon based hydraulic fluid and also resistant to Jet A fuel.
The polymer body of the tape, unlike the TS1228 and SF2470 sealants
(cure in place dry to touch) is soft and tacky to the touch when
cured.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIGS. 1 and 2 show a block of cured TS1228 aircraft fluid
resistant sealant before testing as set forth herein.
[0023] FIGS. 1A and 1B show fluid spray test results for Jet A and
Skydrol.RTM., respectively.
[0024] FIGS. 2A and 2B show submersion test results for Jet A and
Skydrol.RTM., respectively, for the cured polyurethane aircraft
fluid resistant sealant,
[0025] FIG. 3 is a perspective view cutaway of a gasket using at
least in part Applicant's aircraft fluid resistant polymer as part
of a body thereof.
[0026] FIG. 4 illustrates a view of a gasket in which Applicant's
aircraft fluid resistant polymer is used, in a top view showing an
inner and outer perimeter and fastener perimeters in a
non-perimeter portion.
[0027] FIGS. 4A, 4B, 4C, 4D, 4E, and 4F illustrate various
configurations of a gasket which uses Applicant's aircraft fluid
resistant polyurethane sealant as all or a part thereof, in a
straight cut (FIGS. 4A and 4B) overcut (FIG. 4C) undercut) (FIG.
4D) configuration, with FIGS. 4E and 4F showing an outer perimeter
and gasket subject to compression between a workpiece and a
base.
[0028] FIGS. 4G and 4H show the method of making and use of a fuel
resistant perimeter encapsulating a mesh.
[0029] FIG. 5 shows an injection assembly having two compartments
for use with Applicant's two component aircraft fluid resistant
mix, illustrated making a cure in place wet seal.
[0030] FIG. 6 illustrates, when viewed in conjunction with FIG. 8,
a cartridge assembly for use with a pneumatic spray gun for
applying a two-part aircraft fluid resistant polyurethane coating
to an aircraft part.
[0031] FIG. 7 illustrates one environment for use with Applicant's
aircraft fluid resistant polyurethane sprayable coating; namely, an
exterior surface of an aircraft fuel tank.
[0032] FIG. 8 illustrates a side view of a spray gun and cartridge
assembly for applying Applicant's sprayable aircraft fluid
resistant polyurethane coating to an aircraft part.
[0033] FIG. 9 illustrates a sealant for use with a backshell for
connecting a cable to a connector.
[0034] FIGS. 9A-9E illustrate a fluid resistant backshell sealant
and a method for encapsulating part or all of a space within a
boot, the boot surrounding all or part of the backshell and some of
the wires as well,
[0035] FIG. 10 illustrates a stretchable tape with aircraft fluid
resistance for wrapping electrical connectors. FIGS. 10A, 10B, and
100 illustrate a stretchable aircraft fluid resistant tape used to
wrap cable and cable connectors.
[0036] FIG. 11 illustrates a fluid resistant, clear sealant for use
in seat tracks of aircraft. FIGS. 11A and 11B illustrate an
aircraft fluid resistant sealant used as a filler in an aircraft
seat track.
[0037] FIG. 12 illustrates an aircraft antenna having an aircraft
fluid resistant coating on at least part of a leading edge
thereof.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0038] Applicant provides a two-part, polyurethane aircraft fluid
resistant sealant, such as a gasket, tape, spray sealant, or
injectable sealant, used at least in part, to make a sealant on
aircraft parts. Applicant's sealant may be provided, in some
embodiments, by use of TS1228 (available from KBS Chemical, Dodd
City, Tex.) a two-part polyurethane that, when mixed, cures to form
a watertight, tough, workable, durable elastomeric seal and may be
used as all or part of a sealant on an aircraft part assembly, in
some embodiments, a gasket, tape, injectable, or a sprayable
sealant.
[0039] The TS1228 polyurethane sealant was tested in accordance
with RTCA DO-160G Section 11, Fluids spray and submersion
susceptibility to simulate accelerated real world application
scenarios. All testing was performed at room temperature and only
applicable fluids were tested (see Tables 1 and 2).
[0040] FIGS. 1 and 2 illustrate test specimens pre-immersion and
pre-spray. FIG. 1A illustrates submersion results for a body
comprised 100% of cured TS1228 after 168 hrs. in Jet A, visual
inspection showing no change dimensionally and a 2% weight gain
(see Table 1). Weight gain after 24 hours was 1%, The same
material, TS1228 is illustrated in FIG. 1B after 168 hrs. of
submersion in Skydrol LD-4, a phosphate ester based aircraft
hydraulic fluid. An increase in weight of about 7% after 24 hours
(19 percent after 168 hrs) in Skydrol LD-4 is observed. Both
results are believed to be appreciably better than comparable
products. (Table 1, for submersion test results and after 24 and
168 hrs. for a total of 16 different liquids, including Jet A,
Skydrol.RTM. LD-4, and Mobil Aero HF.)
[0041] Submersion testing involves placing the sealant samples in a
glass basin and completely submerging them in the fluid at room
temperature and ambient air pressure. The samples are removed after
24 hrs. of exposure, air dry for 24 hrs, visually inspected,
examined and weighed. They are then placed back in the fluid until
a total of 168 his, of exposure is complete, then air dried,
visually inspected, examined, and weighed.
[0042] TS1228 was also tested for aircraft fluid spray exposure and
FIGS. 2A and 2B illustrate TS1228 after 24 hrs. of spray in Jet A
fuel (FIG. 2A), Skydrol LD-4 (FIG. 28). FIG. 2 shows the test
assembly pre-testing. After 8/16/24 hours of spray, Jet A fuel
showed the following weight change: 0.08%/0.06%/0.07%. Visible
inspection and examination showed no physical deterioration. FIG.
2B shows Skydrol LD-4 after 24 hrs. The 8/16/24 hr. weight change
is 0.65%/1.02%/1.66%, visible inspection and examination showing no
physical deterioration, Table 2 attached shows seventeen fluids
tested and results.
[0043] Applicants' SF2470 (KBS, Dodd City, Tex.) is a two-part
polyurea cure in place sealant with workability, removability,
toughness and durability. Where the dry to touch time of TS1228 is
15-30 min. at 77.degree. F., SF2470 is 8-20 min. Dry through means
a 6 pound thumb press and 90.degree. turn at 77.degree. F. does not
leave a permanent impression. Dry through time for TS1228 is 3-6
hours and SF2470 is 1-2 hours.
[0044] TEST SPECIMENS--Both Spray and Submersion
[0045] Material under test--Ay-DEC.RTM. TS1228 Injectable Sealant,
as cured, measuring approximately 1.8''.times.1.1''.times.0.9''
with an embedded wire
[0046] TEST ASSEMBLY--Both Spray and Submersion
[0047] A length of wire sufficient to hang specimen from rack was
cut, measured and the mass was recorded. The material was injected
into a "Peel-A-Way" disposable mold (R-40). The wire was embedded
into the sealant. The specimens prepared for testing were allowed
to cure for a period of 24 hours and then were removed from the
mold. The mass of each test assembly was measured and recorded.
[0048] Applicants' cured sealants have a hardness (Shore A 50-60 in
one range, Shore A 20 to 80 in another), elasticity (meaning
elastomeric), moisture proof ability (observed and salt fog test),
thermal range (-85.degree. F. to 275.degree. F.) and ability to
withstand thermal and pressure cycling, either as a sprayable on
the surface of an aircraft part, an injectable or on a gasket
between facing surfaces under compression, or tape.
[0049] Applicants sealant is also flame retardant under 14 CFR
25.853(a), Appendix F, Part 1(A)(1)(ii) (12 second vertical burn).
It is amber, VOC-free, solvent-free, and visually clear in coating
up to about 1/4'' to 1/2''. Moreover, it is UV resistant, being
exposed to over 5,000 hours of UV light without degradation.
[0050] Applicants aircraft fluid resistant polymer sealant has a
first part, resin which may have, at about 77.degree. F. of
viscosity between 70 to 250 cps, and a second part, such as a
hardener, which may have at 77.degree. F. viscosity of about 600 to
1200 cps. The gel time of a 10 gram mass at about 77.degree. F. is
less than about 15 mins. and it reaches full cure at about 8 to 24
hours. Thus, it may be termed fast curing. It has a working life
after mixing of about ten minutes or less. It has a shelf life in
original packaging and use within 24 hours after opening, of about
nine months. It may, in some embodiments, have a peel strength of
about 4.92 lbs. per inch width (4-6 in one range and 2-10 in
another range), a tensile strength (ASTMD 412) of about 260 psi (or
greater than 100 psi) and, in testing as an injectable, shows no
corrosion present after 3000 hrs. salt fog (ASTMS 117). Peel
strength is measured on a clean, dry surface of aluminum 6061/alloy
with a cured 1/8'' thick layer, 90.degree. peel slow, constant
speed. When used as disclosed herein, it should retain its physical
and chemical properties with no or minimal loss in functional
properties.
[0051] FIG. 3 illustrates the use of Applicant's aircraft fluid
resistant sealant in a gasket 10a with a body 12 and a skeleton 22.
FIGS. 3 and 4 illustrate a gasket 10a/10b with body 12. Body 12 may
include an outer perimeter 14 and an inner perimeter 16 (gasket
10b, FIG. 4), in some embodiments, fastener perimeters 20, as well
as a non-perimeter portion 18. Gaskets 10a/10b may also include a
skeleton 22, which has openings, and may be flat, and is typically
encapsulated. All or part of body 12, including 14/16/18/20, may be
made from any of Applicants aircraft fluid resistant sealant. In
some embodiments, non-perimeter portion 18 is a soft, tacky gel as
described in U.S. Pat. No. 7,229,516, and one or more of 14/16/20
may be Applicant's fluid resistant polymers. In other embodiments,
it is the soft, tacky aircraft fluid resistant gel as set forth
below in FIG. 10.
[0052] Applicant's aircraft fluid resistant sealants TS1228, SF2470
or U1020/P1021 may be used to comprise any part or all of gasket
body 12/14/16/18/20 and the rest of the body (if any) may be a
polyurethane gel as set forth in U.S. Pat. Nos. 6,530,577
6,695,320; and 7,229,516, incorporated herein by reference. There
may be no perimeter portions when the entire body is comprised of
TS1228, for example.
[0053] Any gasket comprising at least in part body 12 may be made
according to the methods described in the foregoing patents. When
perimeter parts are made from Applicants aircraft fluid resistant
sealant, they may be made according to US Publication No.
2014/0167367, incorporated herein by reference.
[0054] FIG. 5 shows a use of the aircraft fluid resistant sealant
being used as part of an injectable assembly 24, which includes two
compartments 26/28, in some embodiments, one part for polyol and
one part for isocyanate, the two parts being, in some embodiments,
approximately a 2 to 1 volume ratio. The assembly is shown being
used to apply a wet (uncured) seal around fastener holes 30.
Injectable assembly 24 may have a forcing element 29 acting on the
two separate compartments and forcing each to mix in through a
mixing straw or nozzle 24a, from which they will emerge as a
viscous liquid to cure in place on the gasket or aircraft part. A
gasket made at least in part by Applicant's aircraft fluid
resistant sealant may have either a fastener perimeter 20 cured in
place during the manufacturing process of the gasket, or fastener
holes or perimeters 30 may be left without a perimeter and may use
a wet seal about the fastener holes when installed on an aircraft.
The wet seal may include an uncured polyurethane TS1228 mix 32
injected when the gasket 10a/10b is placed on the workpiece and
just before the fasteners are inserted through holes 30. The
uncured mix cures to form a tough, aircraft fluid resistant
polyurethane seal around the fastener and helps prevent corrosion
while maintaining an environmental seal. More generally, TS1228 or
SF2470 may be used as a cure-in-place injectable in any void or
space on an aircraft where fluid resistance is needed and flame
retardant is helpful also. In other embodiments, gaskets may be
made with U10201P1021 where tackiness and softness is needed along
with fluid resistance.
[0055] FIGS. 4A, 48, 4C, and 4D illustrate Applicant's at least
partially fluid resistant gaskets 10a/10b used between a base and a
workpiece, which base and workpiece typically have generally
parallel surfaces and place the gasket all or part, under
compression therebetween. In these illustrations, the gasket is
seen to have a non-perimeter portion 18 and an outer perimeter
portion 14, (the gasket may also have a fastener perimeter 20
and/or an inner perimeter 16). In FIG. 4A, it is seen that the
gasket may be die cut such that the outer perimeter of the gasket
lies about even with the edge of the workpiece (the base is shown
in FIG. 4F only). In this Figure, the skeleton 22 is a woven or
mesh material, flexible. This is considered "straight cut" and
compression will be applied to the entire gasket body, including
the outer perimeter when fasteners or the like are used. FIG. 4B
shows that a skeleton 22a may be a non-woven or non-mesh material
like an impervious sheet. In FIG. 40, it is seen that the gasket is
made slightly larger (for example, about 2 mil to 750 mil or about
30 to 400 mil) so that the outer (or inner) perimeter extends
beyond the edges of the workpiece in a pre-compressed state. FIG.
4C can be considered an overcut gasket. FIG. 4D is an undercut
gasket where the gasket is cut slightly smaller (for example, about
2 mil to 750 mil or about 30 to 400 mil) at the outer perimeter
than the outer perimeter of the workpiece. In FIG. 4E it is seen
that a straight cut, under cut or overcut, may create an aircraft
fuel resistant perimeter 14/16/20 (inner, outer or fastener),
sealing completely around the workpiece WP, protecting a
non-perimeter portion 18 that may or may not be a fluid resistant
polymer or a tacky polyurethane gel. It is noted that the use of
all perimeters 14/16/20 or some perimeters may provide for an
entire gasket when under compression that is fluid resistant even
when non-perimeter portion 18 may not be. That is, perimeters
14/16/20 may be configured such that, after compression, the only
exposed portion of the gasket body is comprised of aircraft fluid
resistant sealant.
[0056] FIGS. 4E and 4F show a perimeter portion 14, which may be an
aircraft fluid resistant sealant, which does not physically
encapsulate and cure around the skeleton 22/22a as seen, for
example, in FIGS. 4A, 4B, 4C, and 4D, and in FIGS. 4G and 4H. FIGS.
4E and 4F show the body 12 undercut such that under compression as
seen in FIG. 4F, the outer edge of 14 is about aligned with the
outer edge of the workpiece or bulges out. In FIGS. 4E and 4F, the
portion of the gasket body shown in the Figures may be added at or
about the time (or anytime) the workpiece is connected to the base
by using an injectable assembly 24 with a mixing nozzle 24a.
[0057] In FIGS. 4G and 4H, a perimeter 14/16/20 is provided to a
gasket having a non-perimeter portion 18, which perimeter may be
fluid resistant sealant and may be created by manufacturing a
gasket with a portion of skeleton 22 extending beyond non-perimeter
portion 18. In other words, a gasket with a skeletal perimeter
initially sticking out beyond the body. Then, at the worksite when
a gasket is placed between the workpiece and the base, a perimeter
may be applied as illustrated in FIG. 4G with an uncured mix
injected, poured or otherwise applied along the edge so it contacts
and cures at least on that portion of the skeleton extending beyond
the non-perimeter portion 18. Applicant's aircraft fluid resistant
sealant cures fairly quickly, typically less than about 30 minutes
and, in some cases, less than 15 minutes, and at the worksite
(after applying the uncured mix and before it cures), one can use a
tool straightedge or shaped tool to provide a straight cut as seen
in FIG. 4H. solid line extending down from the perimeter of the
workpiece to the base. Or, a shaped tool may be used to provide a
fuel resistant perimeter with a shape that extends outward, shown
by the dash line in FIG. 4H. It is to be noted that at least some
of the embodiments of the gasket set forth herein may include a
body being at least partially tacky, such as a body made at least
in part by the tacky gel disclosed in U.S. Pat. No. 7,229,516, or
U1020/P1021 (fluid resistant). Moreover, the aircraft fluid
resistant body may have some tackiness, including for example, by
applying to a surface thereof after cure, a thin veneer, such as
about 1 to 10 mil, of the tacky gels disclosed in U.S. Pat. No.
7,229,516.
[0058] Although the gasket depicted in FIG. 4 as having a basic
polygonal shape for sealing around a simple flange or against
mating surfaces that surround an opening, it will be appreciated
that the gasket is not limited to this or any other shape. Indeed,
the gasket can be manufactured in a variety of shapes, sizes, and
configurations. Woven fibers of the skeleton can be selected from a
variety of fibers, including but not limited to, fiberglass fibers,
carbon fibers, aramid fibers, cotton fibers, and polyester fibers.
It is to be appreciated that other types of woven sheets having
strands of threads in bundled fibers woven together in a variety of
perpendicular and non-perpendicular, symmetrical or non-symmetrical
patterns are possible.
[0059] FIGS. 5, 6, and 8 illustrate uses of Applicant's aircraft
fluid resistant sealant as a two-part polymer sprayable (mix and
spray simultaneously), which has, when cured, aircraft fluid
resistant properties. The sealant is for spraying on aircraft parts
to provide a tough, durable, workable and removable, sprayed on
sealant coat. It has been found that a cartridge assembly 40 may be
used for applying a two-part polymer sealant coating which results
in a tough, visibly clear aircraft fluid resistant, sprayed on
polymer sealant coat 42, the cartridge assembly with two parts used
with a pneumatic mix and spray gun 44. Cartridge assembly 48 may
have body 46 comprising a first compartment 48 and a second
compartment 50. The first compartment may contain a first part of
the two-part polyurethane or polyurea mix, for example, a polyol
and the second compartment 50 may include a second part, such as an
isocyanate. The polyol and isocyanate typically combine and mix in
a nozzle 52 and are emitted as a spray. In one embodiment, a two
part polyol to one part isocyanate ratio by volume is used. The
spray may be sprayed on any aircraft workpiece, including the
exterior and/or interior of hydraulic fittings, joints, surfaces,
fuel fittings, tanks or surfaces, galleys, floors. cargo bays, and
the like. Applicants' sealant may be applied to vertical aluminum
alloy surfaces (sprayed on in some embodiments with Sulzer Mixpac
MixCoat Spray Gun) in one embodiment, modified with compressed gas
port on tip of nozzle 52 of the mixing straw to break up the mix
into small particles. Typically HVLP dispensers or air spray guns
will not be used, rather airless or air assisted spray equipment
may be used. For more details regarding the use of a clear
sprayable sealant and its optical properties (see '196 publication,
incorporated herein by reference).
[0060] FIG. 7 illustrates two additional uses of applicant's
sprayed on sealant coat 42. First, on the surface-outer or inner,
of the fuselage of an aircraft. The second, as a secondary fuel
barrier on aircraft fuel tanks such as the center wing box tank
illustrated. Embodiments of a clear sprayable sealant for aircraft
exteriors may have peel strengths of 25-30 piw and are flame
retardant, per 12 second vertical burn.
[0061] Applicant's TS1228 or SF2470 sealant, whether used as an
injectable, sprayable, gasket or tape, may be used in a thickness
of about 3 to 60 mil in one range or about 10 to 50 mil in another
range or up to W in a third range and, in these ranges, and has
sufficient clarity to see cracks (for example, when used as a
sprayable) in the underlying aircraft part, while still being
resistant to Jet A fuel and Skydrol as set forth herein.
[0062] Applicant's aircraft fluid resistant polyurethane sealant is
VOC and solvent-free. It displays good cohesion, when sprayed on or
applied in an uncured condition, to a metallic or non-metallic
surface. It displays good cohesion to a knitted or woven mesh,
metallic or non-metallic of a gasket when used as part of a gasket
body. A gasket made at least in part of Applicant's aircraft fluid
resistant sealant work well for corrosion resistance on an aircraft
workpiece comprised of an aluminum alloy. Applicant's sealant, in
an uncured but mixed condition, may have a viscosity typically
between about 700 and 1200 cps, allowing it to be sprayed or
injected and poured pursuant to methods found in U.S. Pat. No.
9,701,388, and the other documents incorporated herein by
reference.
[0063] FIGS. 9-9E illustrate the use of two part, cure in place
TS1228 in a cable and connector assembly 60. A method set forth
herein describes the installation in an aircraft for use with
injectable sealant TS1228 or SF2470, including fluid resistance and
moisture protection to the connector. Cable and connector
assemblies are used in a number of environments, including carrying
electrical signals in aircraft. Cable and connector assemblies
typically include a connector 62, which may be a plug (male) or a
receptacle (female) connector, typically having multiple
electronically conductive prongs or recesses (not shown), and a
cable or a cable bundle 64 comprising multiple wires for connecting
to multiple plugs or receptacles for transmitting electrical
signals. Typically, a connector backshell 66 is used to help engage
the cable or cable bundle to the connector. Connector backshell 66
has components specifically designed to be placed around that
portion of a connector (plug or receptacle) which contains the
facilities for attaching wires or cables. Backshell 66 is used to
shield the wire connection points having interconnecting cable and
a connector. Some backshells may include a cable clamp to secure
the cable to the backshell and the connector. Backshells 66 may be
used with any type of connector to protect the cable connections
and to provide strain relief to the solder joints. Backshells may
be straight, 45.degree. or 90.degree. as required by the design.
Illustrated is a straight backshell 66, which includes a coupling
ring 68 that may threadably couple the connector 62 to matching
male or female connection (not shown). A molded boot 70 may be
provided, such as an AvDEC feet shrink molded boot. Molded boots
are available from many different sources and may be, as here, heat
shrinkable to provide environmental protection to the coupling.
[0064] Following the method set below, it is seen in FIGS. 90 and
9E that boot 70, covering at least the upper part of the cable and
connector assembly, may be at least partially filled with fluid
resistant sealant 72, such as TS1228 or SF2470 as set forth herein,
which will cure to provide a tough, hard, durable environmental
sealant for providing resistance to fluids as set forth herein.
[0065] The surfaces should be cleaned with a clean cloth moistened
with a cleaning solvent, such as isopropyl alcohol. Surfaces should
be free of dirt, oil, grease, and other contamination prior to boot
installation, including the cable, the connector, and the
backshell.
[0066] The ends of molded boot 70 are labeled H (and lower) and J
(upper). Slide the boot "J" end first over the electrical
connector, Ensure that "H" end is facing the connector. Heat the
"H" end of the boot with a hot air tool capable of producing
sufficient heat to fully recover (shrink) the boot. The boot should
be located and shrunken uniformly around the connector backshell,
(leaving typically at least the lower part of the connector and the
coupling ring uncovered) and only until it shrinks uniformly around
the backshell. With the assembly held vertical, apply heat to the
"J" end of the boot, moving up from "H" end. The molded boot may be
removed by disconnecting the receptacle and plug and scoring the
surface of the molded boot and concentrating the heat on the scored
line. The boot should begin to separate along the line after which
it can be peeled off. Injectable assembly 24 should be held firmly
in place above the annulus around the cables or wires while forcing
element 29 urges uncured mix 32 into the void. When cured, it will
help create a moisture barrier between the regular surfaces and
providing corrosion protection.
[0067] A sealant is provided for gasket, tape and injectable, where
hardness is not needed but tackiness is, the sealant comprising
soft gel in a tape, injectable or gasket, the gel with resistance
to at least one of the three types of hydraulic fluid as well as
Jet A fuel. In the form of a stretchable tape as illustrated in
FIGS. 10, 10A-C, the tape may be to wrap cable connectors where
they are in close proximity to hydraulic fluids. This two part
polyurethane gel is available from KBS, Dodd City, Tex.
U/1020/P1021 and when cured is tacky and soft, between 30-150
measured with a 35 gram half cone penetrometer. They may also be
used in conjunction with injectables. See FIG. 10A.
[0068] FIG. 10 illustrates a stretchable; fluid resistant tape 80
that contains a cured mix 82 of U1020/P1021. This foam is at least
partially or fully opened cell foam 84, It is resistant to
hydraulic fluids, such as Aeroshell 31 (a synthetic hydrocarbon
hydraulic fluid),
[0069] The gel; when subject to submersion in Aeroshell 31 showed
the following results: 24 hours/1.7% weight gain; 48 hours/2.9%
weight gain; 72 hours/3.9% weight gain; 5 days/5.2% weight gain; 10
days/5.4% weight gain; 20 days/5.5% weight gain; and, 32 days/5.5%
weight gain. A weight gain of less than 10% for 24 hour immersion
of the gel may be considered hydraulic fluid resistant, synthetic
hydrocarbon.
[0070] Tape is typically provided in a roll and, as set forth
herein, may provide some tackiness or stickiness to surface for
optimal corrosion protection. It also passes 12 second vertical
burn. It may be used with stringers, antennas, door shelves, access
panels, windscreen installations, and other suitable locations.
[0071] FIGS. 11, 11A, and 11B illustrate a seat track sealant 90
for maintaining the position of a seat in an aircraft interior.
Seat track sealant 90 may have an upper surface 90a. An injectable
two-art sealant, such as TS1228, may be used in a seat track using
injectable 24 to provide a cure in place seat tracker sealant 90
that provides a tough, durable, clear seal that keeps debris from
entering the seat track, yet is removable, that is, has low
adhesion to the walls of the seat track. In some embodiments, seat
track sealant 90 may be filled to the level of top wall 90a. The
injectable assembly 24 may be comprised of AvDEC Part No, SF2470,
which, while it cures to amber, still retains sufficient clarity
that cracks, debris or corrosion beneath the surface of the sealant
may be readily identified (visually clear). This product is a
two-component polyurea that cures to full cure in less than 4 hours
and gels in 8 to 14 minutes. It has a peel strength of between 2
and about 10 piw, and passes salt fog 3000 hr. ASTMB 117, as well
as 12 second vertical burn, 14 CFR Part 25 subpart d, Section
25.853, Compartment Interiors, and Section 25.855; Cargo or Baggage
Compartments. The material will form a complete environmental seal
but is capable of being cleanly pull out of the track seat
application in one piece yet retains its tensile strength greater
than 100 psi (ASTNB 412).
[0072] FIG. 12 illustrates an antenna sealant 96 for the exterior
of an aircraft, in some cases, an antenna that depends below the
fuselage of an aircraft behind at least some of the landing tires.
Thus, the antenna may be subject to debris; such as rocks and
pebbles; getting kicked up and striking the leading edge,
especially when landing on unimproved runways. Applicant provides a
two-component polyurethane material in some embodiments, spray or
brush on TS1228 that cures smoothly and rigidly to the aircraft
surface, including leading edge 96a, and at least part way to
trailing edge 96b. Antenna sealant 98 being a two-component
material that cures smoothly and rigidly to the surface of the
antenna. It creates a watertight seal that can endure the toughest
operational environments. Its rigid cure means increased abrasion
resistance. It removes easily facilitating quick repair and
inspections. In some embodiments, the hardness is in the Shore A
range, for example, about 20 to 80, and it cures to full cure in
less than 8 hours. The peel strength may be greater than 4 piw, in
some embodiments, in the range of 4 to 10 piw. It passes the 12
second vertical burn test as set forth above and 3000 hours soft
fog per ASTMB 117.
[0073] Although the invention has been described with reference to
a specific embodiment, this description is not meant to be
construed in a limiting sense. On the contrary, various
modifications of the disclosed embodiments will become apparent to
those skilled in the art upon reference to the description of the
invention. It is therefore contemplated that the appended claims
will cover such modifications, alternatives, and equivalents that
fall within the true spirit and scope of the invention.
Submersion Test Results
TABLE-US-00001 [0074] TABLE 1 TS1228--Bare Pre-Test Fixture Total
Sample Change Sample Fluid Type Weight (g) Weight (g) Weight (g)
(%) 1 Jet A Fuel 0.1129 23.9631 23.8502 0% 2 Autozone Brake Fluid
0.1041 22.5095 22.4054 0% 3 Skydrol LD-4 0.1167 21.6004 21.4837 0%
4 AGS Silicone Brake Fluid 0.109 22.8788 22.7698 0% 5 Royco 782
0.1184 21.6808 21.5624 0% 6 White Mineral Oil 0.11.95 23.3562
23.2367 0% 7 Royal Purple Synthetic 0.1158 21.6241 21.5083 0% 8
Isopropyl 0.1196 21.8139 21.6943 0% 9 Denatured Ethyl 0.1263
22.4003 22.274 0% 10 Sky-Kleen 0.1184 23.1272 23.0088 0% 11
Dynalene EG 0.1168 22.5846 22.4678 0% 12 Dynalene PG 0.134 22.6518
22.5178 0% 13 De-icing Fluid PA 0.1219 21.1519 21.03 0% 14
De-ionized Water 0.1198 22.2668 22.147 0% 15 Mobil Aero HF 0.1264
22.235 22.1086 0% 16 5% NaCl Solution 0.1119 23.0594 22.9475 0% 24
hours 168 Hours Total Sample Change Total Sample Change Sample
Weight (g) Weight (g) (%) Weight (g) Weight (g) (%) 1 24.0871
23.9742 1% 24.3557 24.2428 2% 2 23.2124 23.1083 3% 24.3112 24.2071
8% 3 23.0662 22.9495 7% 25.7519 25.6352 19% 4 22.994 22.885 1%
23.0107 22.9017 1% 5 21.8689 21.7505 1% 21.8248 21.7064 1% 6
23.4525 23.333 0% 23.4303 23.3108 0% 7 21.7459 21.6301 1% 21.737
21.6212 1% 8 21.985 21.8654 1% 22.3207 22.2011 2% 9 22.7273 22.601
1% 23.4913 23.365 5% 10 24.3259 24.2075 5% 26.6327 26.5143 15% 11
22.7036 22.5868 1% 22.6371 22.5203 0% 12 22.7645 22.6305 1% 22.7245
22.5905 0% 13 21.2707 21.1488 1% 21.1833 21.0614 0% 14 22.2387
22.1189 0% 22.2398 22.12 0% 15 22.3495 22.2231 1% 22.3943 22.2679
1% 16 23.0781 22.9662 0% 23.0756 22.9637 0%
Spray Test Results
TABLE-US-00002 [0075] TABLE 2 % Weight % Weight % Weight Change
Change Change Visual Test Fluid Class (8 hrs) (16 hrs) (24 hrs)
Inspection Jet A Fuel Aviation Jet A Fuel 0.03% 0.06% 0.07% No
change AutoZone Brake Non-Mineral Based 0.30% 0.47% 0.64% No change
Fluid Hydraulic Fluid Skydrol LD-4 Phosphate Ester- 0.65% 1.02%
1.66% No change Based Hydraulic Fluid AGS Scone Brake
Silicone-Based 0.13% 0.12% 0.21% No change Fluid Hydraulic Fluid
Royco 782 Synthetic 0.11% 0.12% 0.22% No change Hydrocarbon Based
Hydraulic Fluid Mobil Aero HF Mineral-Based 0.16% 0.20% 0.17% No
change Hydraulic Fluid White Mineral OH Mineral-Based 0.23% 0.09%
0.18% No change Lubricating OH Royal Purple Ester-Based 0.19% 0.15%
0.14% No change Synthetic Lubricating Oil Isopropyl Alcohol
Isopropyl Alcohol 0.08% 0.06% 0.13% No change Solvent Denatured
Ethyl Denature Alcohol 0.03% 0.03% 0.06% No change Solvent
Sky-Kleen Solvent N/A 0.17% 0.24% 0.52% No change Dynalene EG
Ethylene Glycol 0.24% 0.15% 0.18% No change De-Icing Fluid Dynalene
PG Propylene Glycol 0.22% 0.15% 0.25% No change De-Icing Fluid
De-Icing Fluid N/A 0.61% 1.05% 1.12% Salt Deposits Potassium
Acetate on sample De-Icing Fluid N/A 0.34% 0.31% 0.18% No change
Potassium Formate 5% NaCl Solution Natural Fluid 0.11% 0.14% 0.14%
Salt Deposits on sample De-Ionized Water Natural Fluid 0.07% 0.04%
0.05% No change
* * * * *