A method for installing fragile, high temperature insulation batting in an elongated cavity or in a resilient wire sleeve to form a resilient seal. The batting is preformed to rough dimensions and wrapped in a plastic film, the film being of a material which is fugitive at a high temperature. The film is heat sealed and trimmed to form a snugly fit skin which overlaps at least at one end to permit attachment of a pull cord. The film absorbs the tensile force of pulling the film enclosed batting through the cavity or wire mesh sleeve and is subsequently driven off by high temperature baking, leaving only the insulation in the cavity or wire mesh sleeve

Wang, D. S.

Warren, A. D.

English

NASA Technical Reports Server

United States Patent n^
Wang et al. [45]
4,235,060
Nov. 25,1980
[54].. INSTALLING FIBER INSULATION
[76] Inventors: Robert A. Frosch, Administrator of
the National Aeronautics and Space
Administration, with respect to an
invention of David S. Wang, Orange;
Aubrey D. Warren, Lakewood, both
of Calif.
[21] Appl. No.: 969,756
[22] Filed: Dec. 15,1978
[51] Int. C1.2 B28B 1/52
[52] U.S. Q 52/743; 156/294;
52/232; 150/11
[58] Field of Search 156/293, 294; 52/743,
52/232, 573, 659, 745; 150/11; 264/126
[56] References Cited
U.S. PATENT DOCUMENTS
1,125,303 1/1915 Gammeter 156/294
1,252,415 1/1918 Duckham 52/232
2,304,233 12/1942 Bergin et al 264/126
2,549,513 4/1951 Nicolle 156/294
2,649,923 8/1953 Woppman 150/11
3,368,670 2/1968 Weaver 52/232
3,546,846 12/1970 Sens 53/432
3,922,425 11/1975 Plumberg 428/339
4,133,928 1/1979 Riley et al 52/659
Primary Examiner—James L. Ridgill, Jr.
Attorney, Agent, or Firm—Marvin F. Matthews; John R.
Manning
[57] ABSTRACT
A method for installing fragile, high temperature insula-
tion batting in an elongated cavity or in a resilient wire
sleeve to form a resilient seal. The batting is preformed
to rough dimensions and wrapped in a plastic film, the
film being of a material which is fugitive at a high tem-
perature. The film is heat sealed and trimmed to form a
snugly fit skin which overlaps at least at one end to
permit attachment of a pull cord. The film absorbs the
tensile' force of pulling the film enclosed batting
through the cavity or wire mesh sleeve and is subse-
quently driven off by high temperature baking, leaving
only the insulation in the cavity or wire mesh sleeve.
2 Claims, 3 Drawing Figures'
(NASA-Case-MSC-16973-1) INSTILLING FIBER
INSULATION Patent ( N A S A ) 4 p CSCL 11C
B81-HI317
Unclas
https://ntrs.nasa.gov/search.jsp?R=19810005805 2020-03-21T09:06:28+00:00Z
U.S. Patent Nov. 25, 1980 4,235,060
FIG. I /o
4,235,060
INSTALLING FIBER INSULATION
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to installation of insulation,
particularly to installation of high temperature, fragile
fibrous insulation in restricted space.
2. Description of the Prior Art
There is no known prior art dealing with the specific 10
problem, which arose in connection with the develop-
ment of heat resistant seals for aerospace vehicles sub-
ject to surface heating. Such heating can produce very
sure is effected by heat sealing longitudinally as close as
reasonably possible to the batting to provide a snug fit
of the plastic skin thus formed over the batting. Draw-
ing through a resilient wire mesh sleeve (spring) is then
readily accomplished through use of a draw cord at-
tached to an overlapping end portion of the plastic film
skin. The plastic skin absorbs the tensile forces pro-
duced in the drawing. Subsequent heating (baking) to
destructively evolve (drive off) the plastic film leaves
the unaffected insulation fibers in the spring sleeve. The
resulting assembly is cross-sectionally deformable and
therefore useful as a door or hatch seal (or the like). The
method will be seen to be also applicable to the drawing
of insulation into other restricted spaces, especially ifhigh temperatures, well beyond the temperatures at
which ordinary seal materials are destroyed or very 15 they are of relatively uniform cross-section,
adversely affected. Accordingly, ceramic fiber insula-
tion materials available as batting are used. These mate-
rials are relatively fragile, however, and consequently
cannot be installed in, or pulled into, restricted spaces
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a drawing showing a length of high temper-
ature mineral fiber insulation on a thin plastic film in
without mechanically damaging them and destroying 20 preparation for packaging the fiber in the film,
the uniformity of their insulation qualities. FIG. 2 shows the heat sealing operation to enclose
Application of insulation for one purpose or another
is, of course, known in the prior art. U.S. Pat. No.
3,922,425 discloses a material useful in roofing, in which
a thermal insulation composition is enclosed in a plastic 25
film which is dissolved by hot asphalt applied during a
roofing operation. No disclosure concerning emplace-
ment of insulation in restricted spaces is included, how-
30U.S. Pat. No. 2,304,233 discloses a method of insulat-
ing double-wall panels (i.e., refrigerator doors, etc.) to
prevent "slump" or displacement during use. Again the
problem of insulation placement in restricted spaces is
not addressed.
Another U.S. Pat. No. 3,546,846 deals with the pack- 35
aging of insulation material. This method may be con-
sidered to be relevant to the plastic film enclosing step
of the present invention, but does not address the re-
the fiber insulation in a skin of the plastic film.
FIG. 3 illustrates the seal assembly resulting from
pulling the plastic film encased fiber into a wire
"spring" sleeve.
DESCRIPTION OF THE PREFERRED EM-
BODIMENTS
Referring now to FIG. 1, a roughly-shaped, elon-
gated batt 10, of the high temperature mineral fiber
insulation employed is placed over a polyethylene film
11 in a trough-shaped fixture to facilitate manual wrap-
ping of the batt in the film. As previously indicated, the
mineral fiber insulation material is relatively fragile and
cannot be pulled through the wire mesh (spring) sleeve
13 (FIG. 3) in an unprotected form without damage.
From the step illustrated in FIG. 1, the film may be
folded over on itself and hfeat sealed to form a circum-
ferentially continuous enclosure. The heat sealing stepstricted space installation problem, nor does it disclose
the concept of using a fugitive packaging material for 40 is illustrated in FIG. 2. The type of heat sealing device
handling and installation purposes and later evolving 12 used 1S not unllke that used for Plastlc fllm packaging
that material by baking °f various consumer products. Elongated heat applica-
It has been recognized that an effective high heat seal tors are adapted for effecting the heat fusion of the
for doors, exterior panels and the like on aerospace thermoplastic film 11 sufficiently close to the fiber msu-
vehicles can be produced as an elongated assembly 45 Iatin8 material so that the film or skin fits snugly over
comprising a spring wire mesh sleeve with a high tern- the fiber insulation batt within.
After the heat fusion operation depicted in FIG. 2,
the remaining flanges of the plastic film may be trimmed
away so that the fiber insulation material appears to be
50 encased in a relatively uniform tubular skin. One end of
this assembly preferably has some longitudinally over-
lapping plastic film which serves as an attachment for
some pulling means. FIG. 3 depicts the film-encased
high temperature fiber material after it has been drawn
55 through a length of wire mesh sleeving 13. The plastic
film is tied to a pull cord 15 at 14, the cord 15 having
been previously extended through the full length of the
wire mesh sleeve. In pulling the film encased fiber batt
through the wire mesh (spring) sleeve 13, the end 14
fective installation of insulation in restricted spaces, the 60 enters first. In FIG. 3, it is assumed that some excess of
perature fibrous insulation therein. Such insulation ma-
terials are mineral fiber or ceramic types, having very
low mechanical strength preventing their being pulled
or drawn, especially through elongated restricted
spaces. ' ' '. .,
The manner in which the method of the invention
deals with this problem will be understood as this de-
scription proceeds.
SUMMARY OF THE INVENTION
In view of the special problems and applications
aforementioned, it may be said to have been the general
objective of the invention to provide a method for ef-
method substantially protecting the insulation itself
from substantial mechanical forces during installation,
while also insuring uniform and effective placement of
the insulation.'
In accordance with the method of the invention, 65
roughly dimensioned batts of the fragile, high tempera-
ture insulation' material are wrapped in a plastic film to
form a "sausage casing" therefor. Circumferential clo-
the film encased fiber material is extant at both ends of
the wire mesh sleeve, however such excess is readily
trimmed away.
The wire mesh (spring) sleeve is preferably of mate-
rial such as Inconel 750 or the like in view of its spring
characteristics and heat resistance.
The final process step involves baking the FIG. 3
assembly at an elevated temperature, for example 800°
4,235,060
10
F. for the polyethylene film suggested. At that tempera-
ture the film "clean burns" completely and the fiber
insulation is unaffected, except that it is released for at
least some radial expansion within the wire mesh sleeve.
The film material is substantially eliminated from the
finished assembly, which can then be incorporated as a
high temperature seal.
Typical light-weight, high temperature ceramic (min-
eral) fiber materials for the batting 10 include various
known materials such as saffil high temperature alu-
mina. Alumina/zirconia fiber batting is also a possible
insulation for the type of application.
The seal assembly of FIG. 3, produced in accordance
with the process has various high temperature sealing 15
applications. In certain aerospace vehicles where high
aircraft surface temperatures are experienced, doors
and hatches must be sealed against this heat, in addition
to whatever sealing is required against air pressure dif-
ferentials.
The seal produced according to the invention is radi-
ally flexible and resiliency deformable in cross-section.
Accordingly it is readily applied as a heat seal as an
interface between a door, hatch or external access panel
and the fixed structures of the craft.
In one form, the finished (baked out) assembly of
FIG. 3 may be covered by one or more sleeves of
woven or braided ceramic fibers. In one application, a
first ceramic fiber sleeve fits snugly over the wire mesh
13, and a second, less coarsely braided ceramic fiber
cloth is wrapped around the first ceramic fiber sleeve
leaving a tangential overlap which extends over the
length of the seal assembly. This tangential flange may
20
25
plate may be attached using a high temperature resistant
adhesive.
The method of the invention will be recognized as
applicable to the manufacture of seals for process fur-
naces, autoclaves, kilns and the like. The method of the
invention will also be recognized as applicable to the
installation of the fragile high temperature ceramic
insulation material in cavities other than in the wire
mesh described, provided those cavities are of relatively
uniform cross-section.
What is claimed is:
1. The method of making an elongated heat seal in
which the heat-resistant material is a relatively fragile
ceramic fiber, comprising:
forming said ceramic fiber into an elongated batt;
wrapping said batt in a film of thermoplastic material
which is fugitive at an elevated temperature, and
heat sealing said film to produce a substantial cir-
cumferential closure of said film into a generally
tubular snug skin around said batt;
attaching a draw cord to one end of said tubular skin
and drawing said film enclosed batt through the
interior cavity of an elongate tubular resilient wire
mesh sleeve to form an assembly, said skin thereby
relieving said batt of the tensile forces attendant to
said drawing step;
and baking said assembly at said elevated temperature
to drive off said film completely leaving substan-
tially only said ceramic fiber bat in place in said
cavity and effecting an even expansion of said frag-
ile batt throughout its length.
2. The method according to claim 1 in which said ,
elevated temperature is defined as high enough to drive
off said film cleanly in a predetermined time, without
then be molded onto a base plate of machinable glass- 35 substantially affecting the structural integrity of said
ceramic using a room temperature vulcanized, high batt.
temperature silicone rubber material. Finally, the base * * * * *
40
45
50
55
60 4
.1
i
v
65
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WASHINGTON. D.C. 20546
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Counsel for Patent Matters
SUBJECT: Announcement of NASA-Owned U.S. Patents in STAR
In accordance with the procedures agreed upon by Code GP and Code
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abstracting and announcement in NASA STAR.
The following information is provided:
U.S. Patent No. : i\
Government or
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NASA Patent Case No.
NOTE - If this patent covers an invention made by a corporate employee
of a NASA Contractor, the following is applicable:
YES NO/ /
Pursuant to Section 305(a) of the National Aeronautics and Space Act,
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Installing fiber insulation

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