CA1061238A

CA1061238A - Flexible laminated thermal insulation

Info

Publication number: CA1061238A
Application number: CA204,764A
Authority: CA
Inventors: Christos J. Botsolas
Original assignee: Johns Manville Corp
Current assignee: Johns Manville Corp
Priority date: 1973-07-16
Filing date: 1974-07-15
Publication date: 1979-08-28
Also published as: IT1016423B; NL7409322A; FR2237764A1; SE7409212L; GB1454874A; JPS5042456A; BR7405815D0; ES428264A1; AU7115074A; FR2237764B1; DE2433717A1

Abstract

FLEXIBLE LAMINATED THERMAL INSULATION
Abstract of the Disclosure A flexible multilayer jacketing material for covering bare pipes or thermal insulation on pipes, etc., is a composite of an interior surface film of a metallized polyethylene terephthalate with its aluminum coated internal face bonded to one face of a central layer of glass fiber-reinforced asbestos paper which has its other face bonded to an exterior surface film of polyvinyl fluoride. A
layer of thermal insulation may also be bonded to the above described jacket.

Description

FLEXIBLE LAMINATED THERMAL INSULATION
This invention i5 concerned with laminated flexible thermal insulation jackets for hot and cold pipes, vessels, tanks and ducts. Jackets constructed according to the invention also afford corrosion and flash fire protection for pipes, vessels, tanks, ducts, etc., and afford flash fire protection when used over walls, roofs, panels, etc.
A wide array of materials have been employed lo or suggested for use as jacketing and thermal insulation for a number of different reasons, including a neater appearance, protection against the weather and fas-tening the insulation to pipes. Alone or in various aggregations, these materials have included aluminum and other metallic casings, canvas, asbestos paper as well as coatings of numerous resinous materials. One example is a laminate composed of polyvinyl flouride on a neoprene-impregnated asbestos felt~ Another type of commercial insulation covering material employs fiber glass yarn patterns as a reinforcement between a flame-retardant kraft paper and the face of aluminum foil to ~hich that paper is bonded. The foil may have a pigmented vinyl resin coating on its other face.
The reinforcing yarn patterns are usually rather pro- i minently visible on both sides of the products. Also, the pigmented coating reduces the reflection of heat 7 by the aluminum layer.
The flexible laminated jackets of the instant invention utilize known sheet materials, but two of these have apparently never been employed as elements ~ -2-3,~

3~()6~38 of a composite jacketing material. Moreover, the pres- -ent combinations and arrangements provide unusual and improved combinations of desirable results, including some of an unexpected nature.
Accordingly, the present invention provides a flexible laminated thermal insulation jacket, the - `
improvement comprising a thin film of heat reflective metal on the internal face of a synthetic resin vapor barrier film. The present invention also provides a fire-resistive flexible laminated thermal insulation jacket, the improvement which comprises a layer of felted asbestos fibers containing a binder resin and reinforcing glass fibers.
Other aspects of the invention are concerned ;:, .
with more specific details, combinations or embodiments which may involve such items as a layer of mass-type `
of insulating material bonded to the insulation jacket, a vapor barrier film of a linear polyester resin (e.g.
transparent polyethylene tereph~halate), a reflective aluminum coating on that film, a binder xesin (eOg.~
polyvinyl chloride) in the asbestos layer, fiber glass scrim ~loth in the asbestos layer~ and a fluorocarbon resin, especially a polyvinyl fluoride film9 as the external surface layer. ~-~
! Still other aspects of the invention as well as its benefits and advantages will be apparent to those skilled in the art upon consideration of the following detailed discloæure.
FIG. 1 shows one embodiment of an article of the invention in a greatly enlarged sectional view . , . . . ~ ,, . , ~ ,~ , , . :

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1 wherein relative thicknesses of the layers in the composite jacket material are somewhat distorted for the purpose of clearer illustration.
FIG. 2 is a fragmentary longitudinal sec-tional view of another embodiment of an article of the invention.
FIG. 3 is a fragm~ntary greatly enlarged sec-tional view on the same plane of details of the sama artlcle wherein relative thicknesses of the layers are somewhat distorted for the purpose of clearer illustra-tio~.
FIG. 4 shows another modification in a sec-tional view similar to FIG. 2.
The jacketing materials of the present inven-tion are composite or laminar articles comprising at least two, and preferably tnree, principal layers of a flexible nature that are flexibly bonded into a unitary sheet material suitable for covering flat sur-faces and surfaces having simple curves.
A composite jacket 8 shown in FIG. 1, and also in FIG. 3 with additional layers 9 and 10, is con-structed by adhesively bonding the entire adjacent faces of three preformed sheet materials into an in-tegral jacketing material having an improved combina-tion of properties relative to prior art jackets. In this emhodiment, the interior surface layer intended for contact with conventional thermal insulation sur-rounding a pipe, etc., or with the bare pipe itself in some applications, is a vapor barrier layer in the forrl of a polyester resin film 1 bearing an ultrathin, .: ~

, ' . ~

:
l~lZ38 vapor-deposited coating 2 of aluminum on its internal face. The metal side or face of this metalli~ed resin is bonded by the adhesive 3 to one face of a central layer 4 of asbestos paper in which is embedded a rein-forcing layer 5 of open mesh fiber glass scrim cloth.
Layer 4 also preferably contains a binder resin.
-- Another adhesive layer 6 serves to cement the other face of the asbestos layer 4 to the inner face of an exterior surface layer 7 of polyvinyl fluoride ilm.
`` Although it is contemplated that the interior surface layer 1 of resin may be omitted in some embodi-ments of this invention when a vapor barrier is not needed, the resulting composite thereby loses some de-sirable qualities. The tough resin film 1 serves to ~-- protect the asbestos layer 4 against physical damage;
it provides a convenient, economical and commercially available carrier for the metal coating, a very light weight, flexible and efficient heat reflecting form of insulation; and it protects one side of the thin metal layer 2 against corrosion by sealing the resin side of the metal coating against exposure to any vapors, gases, - and liquids. Such corrosion would greatly impair the efficiency of the layer 2 in reflecting heat radiation~
A wide variety of plastic compositions may be utilized for the surface film 1 in meeting the re-quirements of forming a film that is a suitable sub-strate for vapor metallization and that displays a low ;
permeability for water vapor ~- for example, low enough for a composite jacket rating below about 2 perms, and preferably as low as possible. Linear polyesters, the _ 5 _ :

~)6~`238 poly~eric reaction products of dihydroxy alcohols and dibasic organic acids may be used. Excellent results are obtainable with metallized polyethylene terephtha-late film which exhibits very low permeability for water vapor and high dimensional stability in combina- `
tion with good heat resistance. A resin that is trans-parent is preferred for obtaining the full benefit of the metal coating as a heat reflector.
It is also contemplated that other resins may be used for film 1 as exemplified by polyvinyl ;
chloride~ polyvinyl fluoride, other fluorocarbons, and even copolymers of vinyl chloride and vinylidene r chloride in applications where shrinkage is no problem.
The metal coating may be any metal capable of reflecting heat and of being applied by conventional vapor deposition procedures to form a mirror-like coating 2 on the resin film 1. Thus, the metal may be aluminum, chromium, copper~ nickel, silver, gold, etc.~ or alloys of these or other metals. Aluminum is generally preferred for good results and economy.
Preformed polyethylene terephthalate film with a vapor deposition coating of aluminum on one side is currently available in adequate quantities at reasonable cost.
The thickness of the metallized vapor barrier -layer 1 may range widely~ for instance from about 0.25 to 4 mils (thousandths of an inch)~ but it is typically ;~
between about 0.5 and 1.5 mils. The thickness of the vapor-deposited metal layer 2 is negligible~ usually being ultrathin coating of less than 0.01 mil~ Although ultrathin, the metal layer 2 provides a much lower vapor ;~

. .

~L~)6~Z3~3 permeability in the metallized resin film than dis-played by a plain resin film.
The felted fibrous layer 4 can be any fibrous waterproof mat, but is pre~erably seaple glass mat, or asbestos paper formed from a slurry of individual asbes-tos fibers in water on a traveling wire screen simi- -larly to paper-making operations. The reinforcing glass scrim cloth 5 is introduced at the proper inter-val in the process for a mid-depth location while the asbestos fibers are settling on the screen. Also~ it - is desirable for the slurry to contain a binder mate-rial, such as a latex of rubber or polyvinyl chloride, that remains flexible and increases the strength of ~`
the paper. A flexible polyvinyl chloride binder is generally preferred for its self-extinguishing com-bustion p~operty, and it may be present in an amount of about 10 to 30% ~preferably about 15-20%) of the dry weight of the asbestos layer.
Layer 4 is the bulkiest layer in the com- `
posite, being typically about 15 to 30 mils thick.
This bulk is helpful in minimizing "telegraphing" of the pattern of scrim cloth on the surfaces of the jacket material~ However, the fibrous asbestos layer may be as thick as 40 or more mils or as thin as about 10 mils depending considerably on the desired coef-ficient of conductive heat transfer through the jacket as well as its desired fle~ibility. Both properties are mainly dependent on the thickness of the asbestos layer.
The scrim cloth 5 may be woven from polyethylene ; . .

~ ... . . ... .. . . . . . . . .

~6~3~ :

l terephthalate or nylon threads where the strength of the jacket at high temperatures is not important, but fiber glass threads are usually preferable. The ~eave of the cloth may have a thread count of from 2 X 2 up to 12 X 12, and an 8 X 8 count is typical.
The exterior skin or surface layer 7 is a continuous or unbroken flexible film of a solid resin as exemplified by polyvinyl chloride for indoor usage and fluorocarbon resins or acylic resins1 such as polymethyl methacrylate for general usage. The fluoro-carbons are preferred for most purposes, but the ex-pensive chlorotrifluoroethylene and tetrafluoroethylene polymers seldom, if ever, justify their extra cost over polyvinyl fluoride. The latter is being manufactured in the ~orm of strong films of 0.5 to 4 mil thickness with various pigments incorporated therein. Polyvinyl fluoride film is an extremely durable preformed finish layer for exposure to all types of weather, common sol-vents strong cleaning agents, corrosive liquids and ^
gases.
Polyvinyl fluoride film is desirably ren-dered surface receptive to adhesive bonding by surface activation on both of its faces as may be accomplished according to the teachings of United States Patent Nos.
3,133,854; 3~228,823; and 3,369,959. Those patents disclose pertinent background on surface activation and some of the aclhesives for activated polyvinyl ;~
fluoride surfaces. In addition to the epoxy resins, vinyl addition polymers, polyalkyl acrylates , ;
~91 ; ,, 1 and other adhesives mentioned therein, one may employ the cements based on synthetic rubbers as described in United States Patent No. 2,376,854. In general an elastomeric adhesive is preferred for forming flexible bonds between the flexible layers. The aforesaid ad-hesives may be employed as the bonding age~ts for both faces of the central asbestos felt layer 4, that is in both of the thin layers 3 and 6. In the case of adhesive layer 6, even when the exterior resin skin lo 7 is pigmented, it is often desirable, for maximum -resistance to deterioration from prolonged exposure to sunlight, to incorporate an agent capable of re-sisting such degradation in the adhesive. Such agents are well known and exemplified by the carbon black men-tioned in certain of the aforesaid patents or an ultra-violet absorber, such as a compatible suhstituted --benzophenone or substituted benzotriazole selected from those listed in the chart on pages 1008-1009 of the 1969-1970 Modern Plastics Encyclopedia of Breskin Publications, Inc., Bristol, Connecticut.
FIG. 2 is a fragmentary general cross-section through the thickness taken in the machine direction or longitudinal plane, of another embodiment of the in-vention. It shows a thin, relatively dense laminar jacket 8 to which is bonded a series of contiguous dis-crete strips ~ of inorganic fibrous mat thermal insula-tion. FIG. 3 is an enlarged sectional vie~ on the same plane of the same embodiment as in FIG. 2. It depicts the adhesive layer 10 binding the strips 9 to the .

~t'.' -. . _9 _ "~' . " ,. , 11)63L'~3~
, composite jacket 8 which is composed of the layers designated by reference numerals 1 to 7, inclusive.
The insulating material in layer 9 serves to minimize heat transfer by conduction; hence it is a relatively bulky material containing a substantial volume of voids or dead air space. Flexible polyure-; thane foams or other flexible foamed resins with suitable temperature characteristics may be used for the purpose. However, mat insulations constructed essentially of inorganic fibers, such as glass fibers and mineral wool, are often preferred. They are inco~-bustible and can be employed over a wide-range of operating temperatures. Also, costly ceramic felt in-sulation may be used in some special cases, as where " .
unusually high temperature conditions justify the extra expense. ~ `
Strips 9 may be obtained from relatively -rigid conventional inorganic fiber batts or boards ; ` `
which are impregnated with conventional binding agents~
For example, typical fiber glass boards with densities of about 0.5 to 2 or more pounds pfr cubic foot and thicknesses of about 0.5 to 2 inches or more may be cut i `
into strips of about 0.5 to 2 inches width of uniform rectangular cross-section for rearrangement as strips 9 in the present composite articles. Substantial flexure is usually involved in fitting the products of this invention to pipes and other curved surfacesO
However, flat fiber glass boards or batts do not pos-sess the necessary flexibility for bending in the trans- `
verse direction or any other direction~ because the ~

;
.

-10................................. ", lO~lZ~
individual fibers or strands are deposited in chopped form in a sequence of parallel layers each on top of the preceding layer and then immobilized with a binding agent. There is random orientation of the fibrous material within each of the parallel layers but rela-tively few fibers are oriented in depth to extend through any or all of the layers; hence the orienta-tion of the fibers may be described as essentially planar with the fibers being disposed predominantly within a series of substantially parallel planesr As a result, the insulation board or batt is relatively stiff and its surfaces cannot be stretched or reduced in length or width as is necessary in bending a sheet material of substantial thickness. However, this board can be compressed and reduced in thickness, iSe., in a direction substantially normal to the planar fiber alignment. In the present articles9 the strips 9 are disposed in a way that reorients the planes of fiber orientation so that these planes are substantially `;
perpendicular or normal to the surfaces of the new laminated article rather than parallel thereto. Such ;
reorientation of the fiber planes can be expressed as substantially normal to the laminar jacket and paral- -lel to one another. Thus with the strips 9 aligned in that manner and bonded to a sheet of flexible jacketing material 8, the composite sheet may be flexed with the strips 9 being compressed and be-coming narrower during concave flexure of that side of the composite sheet.
~he adhesive 10 used for bonding the I,~

~0~i12313 mass-type insulation 9 to the surface of the laminar jacket may be a hot melt adhesive or one of the adhe-sives disclosed hereinafter incLuding epoxy resins9 and synthetic nitrile rubber modified with a phenol-formaldehyde resin, as well as others known in the art.
Hot melt adhesives often contain a relatively low molecular weight substance of the group consisting of ester or paraffin waxes, and rosin, alkyd, terpene and coumarone-indene resins blended with a limited pro-portion of such higher molecular weight polymers as ;~
polyvinyl acetate, polybutyl methacrylstes, polyethy lene, polyisobutylene and polystyrene along with a liquid plasticizer~ Among the formulations recommended for general hot melt bonding are mixtures of polyethy-lene, polyvinyl acetate and polyamide reaction prod- ~
ucts of dimerized fatty acids and diamines. ~ -Another embodiment of the ~acketed insulation ~ ;~
of this invention is illustrated in FIG. 4 wherein a very thin aluminum foil 20 is interprosed in the mass insulation to reflect heat radiation. In this partic-ular modification, each of the fibrous mat strips 9 is composed of two sections 18 and 19 bonded to opposite faces of the foil 20 with an adhesive known in the art as effective both on aluminum and on glass or mineral wool fibers. The sections 19 and 20 are cut from the same types of fibrous boards or batts as the unitary strips 9 in the embodiment of FIGS. 2 and 3, and the fiber orientation relative to the laminar jacket 8 and the bonding are also similar. In general, the foil 20 is employed as a primary heat reflector along with ~1361~2:3~

the metal coating 2, and there is some evidence that ` this structure can result in a surprising reduction . in the skin temperatures of outer layer 7 from those obtained under comparable conditions with a jacketed insulation &omposite differing only in the omission of the foil 20.
To illustrate the method of forming a specific -composite jacket material according to this invention, an adhesive coating is applied to one of the two acti-vated faces of a 1.5 mil thick web of a suitable com- .
mercially available polyvinyl fluoride by passing the ~ . .
web through a conventional coating device containing ~ ::
: a solution of a synthetic rubber adhesive of the buta- :
diene-acrylonitrile type in a naphtha-based solvent, ;:~
which is also commercially available. Next, the adhe-sive coating is dried during travel of the web through . an oven; then the coated side of the plastic web is :
laminated in contact with one face of a web of a 25-mil thick suitable asbestos paper product that is advantageously reinforced, as by an internal glass j : fiber scrim cloth of 8 x 8 count and including a poly-vinyl chloride binder resin~ The bonding is accom- ,.:
plished by passage of the assembled webs through nip . .
rolls with an unheated rubber roll bearing on the exposed polyvinyl fluoride face while a heated steel roll bears on the asbestos paper side7 Thereafter, in .
similar procedures, a suitably metallized 0.9 mil web of polyethylene terephthalate is coated on its metal-lized face of vapor-deposited aluminum with the same synthetic rubber adhesive, oven dried and laminated ~, ~0~3~

onto the asbestos face of the asbestos-polyvinyl fluoride composite in the same nip rolls.
The particular jacketing material produced in the aforesaid procedure has an overa~l thick~ess-of 25 mils~ the same as the original thickness of the reinforced asbestos layer, as a result of the com- i pacting of that layer by the nip rolls. It possesses a tensile strength that is usually well in excess of 50 pounds per inch of width and a vapor barrier rating of 0.02 perm (water transmission in grams per hour per square foot per inch mercury pressure differential~
The composite material may be successfully employed in ~ ~-covering thermal insulation having surface temperatures ranging from far below zero (e.g., -200 F) up to 325 ~-375 F range, and the maximum temperature can be ex-tended to 400F or more when the vapor barrier resin - -layer 1 is omitted from the lay-up.
;,. . .
In addition, the aforementioned laminate has greater flame resistance than pure aluminum which melts at approximately 1220F and is the most common jacket for outdoor pipe insulations. The new composite has successfully withstood oven temperatures of 1500F with the glass reinforcing threads remaining intact, shielded -by the asbestos; and there are indications that it will withstand higher temperatures and may provide fire re-sistance at temperatures ranging up to about 2000F~
Still other properties and advantages of such jacket material are set forth hereinafter.
The instant composites may be used for covering practically any type of thermal insulation, including , -14- ~

3~

` 1 calcium silicate, foamed glass and ceramic materials, - such plastic foams as polyurethane and polystyrene ; foams, corrugated asbestos paper, fiber glass and mineral wools in batts and blankets, etc. These - jackets can be employed for covering such kinds of insulation on pipiny systems, tanks, vessels, ducts and almost all types of insulated equipment. It may be desirable in some instances to cover bare pipes and other uninsulated surfaces with the present jack-ets, for example, as protection against corrosive liquids and gases as may be encountered in chemical plants, etc.
To make the compo,ite article shown in FIG.
3, l-inch thick fiber glass boards with a density ap-proximating 2 pounds per cubic foot and a temperature rating of 850F are cut transversely into strips of 1 inch width. A coating 10 of a.conventional hot melt adhesive, as mentioned earlier, is applied in the molten state to the exposed face of the polyester film 1 o: the web of jacketing material. After being reori-ented, the fiber glass strips are bonded with their lengths disposed transversely (i.e., crosswise or op-posed to the machine direction) of that web and in firm contact with adhesive coating 10 while it is still in fluid state. Th~e reorientation involves rotating each strip 90~ about its length, so that the parallel planes in which the glass fibers are predom-inantly disposed are substantially normal to the web or surface of the jacket; also it is desirable for convenient roll storage that these planes extend .

- 1 transversely of the web. Scrips 9 are parallel and preferably in contact with one another, but they are des:rably discrete with no substantial adhesive bonding between their contiguous sides. After cooling of the adhesive, the resulting jacketed insulation may be flexed and bent into substantial curves around axes transverse to said web without cracking, buckling or forming unsightly wrinkles.
In addition to the convenience of fitting a complete insulation as a one-piece material, one or `
adjacent or separated strips 9 may be removed entirely a substantial part of the depth thereof in solving difficult problems of fitting the insulating material around tight bends, small diameter pipes or in crowded locations. .:
The composites of this invention can be easily fitted and fastened with the resin film 7 on the outside as the exposed surface layer and the vapor barrier resin layer 1 in direct contact with the surface ~ -of the insulation or the surface to be covered. Only simple conventional hand tools, such as scissors or knife, ruler, stapler and brush, are needed. The joints are generally overlapped and cemented with a ;
contact adhesive (e.g., a synthetic rubber-phenolic resin type) which will bond the overlapping several inch wide margin or portion of resin layer 1 to the -underlying marginal area of the bondable surface of resln layer 7, (e.g., an activated fluorocarbon resin surface) of the jacket. Alternatively, the overlapped seam may be fastened with staples, desirably 1 made of monel or other corrosion-resistant alloy; but it i 5 often preferable to both staple and cement the jOi.lts. In applications where a vapor or liquid barrier is necessary or desirable, or where the ap~
; pearance of the installation is critical, the staples and overlapped seams may be sealed with a suitable tape.
A tape matching the exterior resin layer 7 is generally preferred; for instance, co~ering and sealing an exte-rior film of polyvinyl fluoride with a polyvinyl fluoride tape of the same composition, color and thick-ness and two-sided activation, but also bearing a coating of a pressure-sensitive adhesive which is pro-tected by a readily releasable paper liner. The prior surface receptive treatment of the polyvinyl fluoride film assures durable adhesion of the adhesive face of the tape to both the exposed surface of the exterior layer of the jacket and to the uncoated surface of the -~
tape itself.
The unique combinations of structural features .;
in the present composite jackets provide outstanding combinations of desirable properties and larger numbers of such benefits than were available in prior art jacket materials, including some advantages which are unique.
Moreover, certain of the structural arrangements pro-duce complementary or cooperative effects. For illus-tration, in the asbestos layer 4, the embedded glass fiber strands of scrim cloth 5 greatly reinforce the strength of the felted asbestos but they have a much lower melting point and flame resistance than the asbestos; however, the asbestos covers and insulates - . . . : . . : ~

3~

1 the glass fibers, and this protection enables the glass fibers to reinforce the asbestos layer, even when the surface temperatures of the outer face of the asbestos exceed the softening or melting tempera-ture of the glass fibers. These complementary pro-tective effects are particularly significant in instal-lations where flash fires may occur and it is important to shield pipe or equipment surfaces from contact with flames. Without the reinforcing fiber glass threads, the asbestos paper would tend to collapse or tear as the resin binder could be decomposed by the heat from a flash fire.
~- Similarly, the internal disposition of the metal coating 2 enables its covering transparent resin - layer 1 to protect the metal against corrosion from acid, alkaline, oxidizing or other corrosive substances (e.g., during careless storage or from the alkali pres-ent in some insulating materials) and thus to maintain its efficiency in reflecting heat radiation. Another cooperative effect resides in the fact that the metal coating greatly enhances the vapor barrier effect of the resin film and permits obtaining very low perm ~-~ ratings with a very thin and flexible metallized resin film. For instance, the mo:isture vapor permeability of uncoated polyethylene terephthalate film is typically ^~ of the order of ten times that of the same film bearing an ultrathin coating of va~r-deposited aluminum.
The inhalation of air-borne dust particles or fine fibers of asbestos is considered to be an occupa-tional health hazard for workers handling asbestos. In ...
. , ' ~ ' 1 the composite of the invention, the surface layers 1 and 7 completely cover the faces of the asbestos layer 4 and thereby minimize or eliminate any hazard for personnel applying it to insulation or any other sur-face. Moreover, in a preferred embodiment of the in-vention using an asbestos paper impregnated with a substantial amount of a flexible binder agent, the asbestos hazard is likewise minimized or eliminated `~
for workers making and using the present laminated jackets. A flexible asbestos paper impregnated with a latex of either rubber o~ polyvinyl chloride can be soaked in water without the delamination which occurs with untreated asbestos paper. Polyvinyl chloride is the prefexred binder in view of its self-extinguishing combustion property. The fibrous asbestos serves as the major insulating component within the jacket for minimizing conductive heat losses as well as providing outstanding flame resistance.
The exterior skin 7 provides resistance to the weather and soiling from various causes, and in the case of fluorocarbons, there is outstanding re-sistance to wind, rain, snow, sandstorms and micro-organisms. For example, the preferred polyvinyl fluoride film is tough, abrasion-resistant and inert, so it is unaffected by substantially all of the strongest common cleaning solvents and detergents, acids and alkalis at room temperature, and usually at elevated temperatures. Its pigmented modifications are generally unmatched in fade resistance and strength retention under outdoor conditions or buried in soil. ~;

1 In addition, it has a low moisture absorption of only 0.5~, coupled with high tensile, tear, impact and burst strengths; also it is suitable for continuous use at 225F and its zero strength temperature is in the 500-570F range.
The present compo.,ite jackets have an excep-tional array or combination of properties that provide an ~musually wide field of ~se in efficiently jacketing hot or cold equipment or its thermal insulation under any atmospheric or soil burial conditions as well as most corrosive conditions likely to be encountered.
In addition to their suitability for continuous use at substantially elevated t.emperatures for periods that are expected to exceed 20 years, the new jackets have an unusual degree of f.ire resistance in respect to retaining their basic configurations at very high temperatures and displaying desirably low smoke ratings.
These laminated jackets are tough and flexible enough so that they may be walked on without cracking or loss of vapor barrier properties; and they resist scuffing, abrasion and accidental punctures as well as tearing from stapling. Thus, they do not present the main-tenance problems of conventional jackets, mastics, etc.. Also, the instant jacket materials require.no painting or repainting, and any surfaces that are soiled, greasy, or contaminated with fungi or bacterial growths from external sources can readily be cleaned .
and/or disinfected, without damage, by using powerful agents including steam, hot water with soap, or strong .
detergents, all commercial organic solvents and ': ~ -.~

~U~3~ .
1 disinfectants. The instant insulation jackets can also be removed for repairing jacketed pipes and equipment and subsequently replaced in an installation that sub-stantially matches the oriyinal in efficiency and neat appearance.
In the preferred embodiment described herein the layer 4 is described as an asbestos felt or paper containing reinforcing fibers. Many other fibrous mats ;
would be suitable as long as they resist deterioration when exposed to water or water vapor, for example, fibrous mats made from glass fibers, ceramic fibers including carbon fibers, and/or synthetic organic fibers such as polyester and nylon fibers.
While only a few embodiments of the present invention are described in detail herein, for purposes of a concise disclosure, it will be apparent to those skilled in the art that other modifications of such articles are within the purview of the invention.

Claims

WHAT IS CLAIMED IS:

1. A flexible composite laminated insulation jacket article, which comprises:
(a) a vapor barrier layer comprising a first polymeric film having deposited on the interior face thereof a thin coating of a reflective metal, said polymeric film being selected from the group consisting of polyester and halocarbon polymeric films;
(b) a fibrous insulating layer comprising asbestos fiber reinforced with an open mesh scrim cloth; and (c) an exterior layer comprising a second polymeric film selected from the group consisting of halocarbon and acrylic polymeric films;
the metal coated face of said first polymeric film being adhered to one face of said fibrous insulating layer, and the other face of said fibrous insulation layer being adhered to said second polymeric film.

2. The article of Claim 1 wherein said first polymeric film comprises a polyester film.

3. The article of Claim 2 wherein said polyester film is transparent.

4. The article of Claim 3 wherein said transparent polyester film comprises polyethylene terephthalate film.

5. The article of Claim 1 wherein said scrim cloth is woven from fiberglass, polyethylene terephthalate, or nylon threads.

6. The article of Claim 5 wherein said scrim cloth is woven from fiberglass threads.

7. The article of Claim 1 wherein said second polymeric film is a halocarbon polymer film.

8. The article of Claim 7 wherein the halocarbon polymer is a polyvinyl chloride resin or a fluorocarbon resin.

9. The article of Claim 8 wherein the halocarbon polymer is polyvinyl chloride or polyvinyl fluoride.

10. The article of Claim 9 wherein the halocarbon polymer is polyvinyl fluoride.

11. The article of Claim 1 wherein said reflective metal is aluminum, chromium, copper, nickel, silver, gold, or alloys thereof.

12. The article of Claim 11 wherein said reflective metal is aluminum.

13. A flexible jacket thermal insulation blanket article which comprises a jacket article as in Claim 1 laminated to a flexible thermal insulation element comprising at least one layer of mass type thermal insulation of low thermal conductivity and which is flexible in at least one direction.

14. The article of Claim 13 wherein said first polymeric film comprises a polyester film.

15. The article of Claim 14 wherein said polyester film is transparent.

16. The article of Claim 15 wherein said transparent polyester film comprises polyethylene terephthalate film.

17. The article of Claim 13 wherein said scrim cloth is woven from fiberglass, polyethylene terephthalate, or nylon threads.

18. The article of Claim 17 wherein said scrim cloth is woven from fiberglass threads.

19. The article of Claim 13 wherein said second polymeric film is a halocarbon polymer film.

20. The article of Claim 19 wherein the halocarbon polymer is a polyvinyl chloride resin or a fluorocarbon resin.

21. The article of Claim 20 wherein the halocarbon polymer is polyvinyl chloride or polyvinyl fluoride.

22. The article of Claim 21 wherein the halocarbon polymer is a polyvinyl fluroide.

23. The article of Claim 13 wherein said reflective metal is aluminum, chromium, copper, nickel, silver, gold, or alloys thereof.

24. The article of Claim 23 wherein said reflective metal is aluminum.

25. The article of Claim 13 wherein said thermal insulating element is selected from the group consisting of inorganic fibers and foamed resins.

26. The article of Claim 25 wherein said thermal insulating element comprises inorganic fibers.

27. The article of Claim 26 wherein said inorganic fibers comprises glass fibers.

28. The article of Claim 25 wherein said thermal insulating element comprises polyurethane foam.