US3206345A

US3206345A - Method and apparatus for making permanently sealed resilient insulation

Info

Publication number: US3206345A
Application number: US160009A
Authority: US
Inventors: Carl A Stickel
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1961-12-18
Filing date: 1961-12-18
Publication date: 1965-09-14
Anticipated expiration: 1982-09-14

Description

Sept. 14, 1965 c. A. STICKEL METHOD AND APPARATUS FOR MAKING PERMANENTLY SEALED RESILIENT INSULATION 5 Sheets-Sheet 1 Filed Dec. 18, 1961 n9 QQ AQ/ o INVENTOR p 14, 1965 c. A. STICKEL 3,206,345

METHOD AND APPARATUS FOR MAKING PERMANENTLY SEALED RESILIENT INSULATION Filed Dec. 18, 1961 5 Sheets-Sheet 2 INVEN TOR.

Sept. 14, 1965 c. A. STICKEL 3,206,345

METHOD AND APPARATUS FOR MAKING PERMANENTLY SEALED RESILIENT INSULATION Filed Dec. 18, 1961 3 Sheets-Sheet 5 F EL/,8

United States Patent 3,206,345 METHOD AND APPARATUS FGR MAKING PER- MANENTLY SEALED RESILIENT INSULATIQN Carl A. Sticlrel, Dayton, Uhio, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed Dec. 18, 1961, Ser. No. 160,009 14 Claims. (Cl. 156'145) This invention relates to improved insulating means and more particularly to a method of and apparatus for replacing the air in the resilient insulation with the gas having better insulating properties and permanently sealing in the gas.

It has been recognized that certain gases with inherently low coeflicients of heat transmission after displacing air from insulating materials will substantially increase the insulating properties of good insulating material such as glass fibers or mineral wool. However, it has been diflicult to provide a simple rapid inexpensive method of and apparatus for permanently enclosing such gases in the glass fibers or mineral wool. It has also been difficult to prevent the leakage of such gases and to prevent the puncturing of the enclosure during the processing of the insulation and during the handling of it afterward. Various means have often been proposed for accommodating the expansion and contraction of the gas during extreme changes in temperature and also in barometric pressure.

It is an object of my invention to provide a simple rapid reliable inexpensive process and apparatus for making a permanently sealed resilient insulation containing a gas having a low coefficient of heat transmission.

It is another object of my invention to provide a simple rapid reliable inexpensive process and apparatus for squeezing air out of resilient insulation and replacing the air with the gas having a lower coefiicient of heat transmission and also enclosing and sealing the gas in the resilient insulation.

It is another object of my invention to provide a simple improved means having high insulating value for protecting the enclosure of the sealed resilient insulation from puncture and leakage during processing and subsequent handling and also to accommodate the expansion and contraction of the gas sealed therein.

These and other objects are attained in the first form in which two spaced parallel conveyer belts have applied to their interior faces a thermoplastic film and a protective strip which are fed thereon at the speedof the conveyer belts. From a roll, pieces of glass fibers or mineral wool are cut and deposited between the protective strip in-between the conveyer belts for feeding to the point where a squeezing roll cooperates with one of the belts to squeeze a gas such as the air out of the resilient insulation. After the material is squeezed by the squeezing roll, the edges of the film are heat sealed on the opposite sides of the resilient insulating material. The gas having the low coefficient of heat transmission is piped into the interior in-between the two sheets or strips of thermoplastic film beyond the point of heat sealing so that as the resilient insulating material reexpands it is filled with this gas. Beyond this point the film in-between the pieces or slabs of the resilient insulation is transversely heat sealed to form a bag by applying flying heat sealing devices extending transversely across the material and move with the material as this is done. Following this point, there is sprayed onto the entire exterior a mixture of materials which will form a closed cell substantially impervious resilient foamed polymer preferably also containing a gas having a low coeflicient of heat transmission. Infrared heaters quickly complete the foaming and curing of this foam polymer and at the next station the slabs are separated by flying cutters which as the movement of the 3,296,345 Patented Sept. 14, 1965 "ice material continues cut the material in-between the air heat sealed transverse closing to complete the insulation package.

In the second form of the invention, the resilient material is fed in-between squeezing rollers into an enclosed chamber having its atmosphere made up entirely of the gas with the low coefficient of heat transmission. Within this chamber after passing through the squeezing rollers, the exterior of the material is coated with a mixture of materials forming a substantially closed cell substantially impervious flexible foamed polymer preferably containing a gas having a low coefiicient of heat transmission; This mixture is foamed and cured under the application of infrared heat. A cutting device controlled by an electric eye cuts the coated material into slabs which are caught below and held while the edges are sprayed with the similar mixture of materials forming a substantially closed cell substantially impervious flexible foam polymer containing the same gas having the low coefficient of heat transmission. These materials are foamed and cured under the application of infrared heat after which the completed slabs pass through a double door sealing arrangement out of the enclosure containing the gas atmospherc.

Further objects and advantages of the presentinvention will be apparent from the following description, ref.- erence being bad to the accompanying drawings wherein preferred embodiments of the present invention are clear- 1y shown.

In the drawings:

FIGURE 1 is a diagrammatic view of the first form apparatus embodying my invention;

FIGURE 2 is an enlarged fragmentary view taken in the direction of the arrow 2 on FIGURE 1;

FIGURE 3 is an enlarged tranverse sectional view taken along the line 33 of FIGURE 1;

FIGURE 4 is an enlarged transverse sectional view taken alongthe line 4--4 of FIGURE 1;

FIGURE 5 is an enlarged transverse sectional view taken along the line 55 of FIGURE 1;

FIGURE 6 is a diagrammatic view of the second form of my invention and;

FIGURE 7 is an enlarged sectional view taken along the line 7-7 of the completed insulation produced by the apparatus shown in FIGURE 6.

Referring now to the diagrammatic illustration FIG-

URES

1 and 2 there is shown a large supply roll 20 provided with a long strip of suitable pervious insulating material such as glass fibers, mineral wool or an open cell foam elastomer. The strip 22 of one of these materials comes off the roll 20 over an idler roller 24 between two feed rollers 26. The feed rollers 26 are driven by an electric motor 28 through the control system 30. The feed rollers 26 are synchronized with the control system 30 so that at the proper time the cutters 32 are operated to cut off the strip 22 into pieces 34 of the length desired. The pieces 34 are deposited upon the lower conveyor belt 36 which passes around a large drive roller 38 and a squeezing roller 40 as well as idler rollers 42, 44, 46 and a series of idler rollers designated by reference character 48a The belt 36 is driven at a faster rate than the supply provided by the feed rollers 26 so that the pieces 34' are spaced a desired uniform amount upon the belt 36.

The upper face of the belt 36 is covered by a thin thermoplastic film or sheet 50 which comes off the feed roll 52. and extends over the surface of the belt 36. This film is preferably made up of one or more layers of vinylidene chloride sheet. However, if desired other forms of heat sealable plastic film or sheet such as vinyl chloride acetate sheet or a copolymer of vinyl chloride and vinylidene chloride or a polyester of etheleneglycol and tereph-thalic acid. With some glass fiber and mineral aaoasae in? wool, there is a possibility that some sharp nedle-like piece may puncture the film 56. In order to avoid this possibility of puncturing, providing such materials are used, I provide a roll 54 of thin open cell foam elastomeric sheeting or kraft paper 56 which is; narrower than the film and of substantially the same'width as the glass fibers or mineral wool 22. From this roll 54 a strip 56 is laid over the film 50 on the belt 36. The pieces 34 of insulation rest on top of the strip 56 in spaced relation as shown in FIGURES 1 and 3.

A second roll 58 lays a strip of material or sheeting 60 on top of the pieces 34. This second roll 58 and its strip 60 are similar or identical to the roll 54 and the strip 56. Thus the pieces 34 are between the

sheeting

56 and 66. On top of the sheeting 60 thereis supplied a film 62 of thermoplastic film which comes off the supply roll 64. The supply roll 64 and the film 62 may be similar to or identical to the roll 52 and film 50.. The film 62 and the sheeting 60 are applied to the tops of the insulation pieces 34 by an upper belt 66 which is driven by a small drive roller 68 and passes around the idler rollers 70 and 72. Both the

belts

36 and 66 are endless and hold the insulation pieces 34 in spaced relation as long as they are in contact with the belts.

The

belts

36 and 66 thus apply the

film

50 and 62 as well as the

sheeting

56 and 60 to the opposite flat sides of the insulation pieces 34. The

drive rollers

38 and 68 for the

belts

36 and 66 are driven by an electric motor 74 through transmission means 76 at identical linear speeds. The squeezing roller 40 and the adjacent portion of the belt cooperate with the cooperating squeezing roller 78 also driven by the motor 74 at a surface speed equal to that of the

belts

36 and 66. The roller 7 8 has a resilient surface of foamed or solid elastomer.

As shown a gas such as the air is being squeezed out of one of the insulation pieces 80 by pressing together the

films

62 and 50. The assemblies of the insulation piece, the sheeting, and the films continue between additional sets of squeezing rollers 32 and 84 having

resilient flanges

86 and 88 of elastomeric material which hold together the edges of the film. These squeezing rollers 82 and 84 also have resilient surfaces of foamed or solid elastomer. These rollers 82, 84 substantially complete the pressing of the air out of the insulation piecessuch as the piece 80 and also prevent any re-entry of air by keeping the edges of the

films

50 and 62 pressed together. The gas such as air Within the insulation pieces 34 between the

film

50 and 62 is replaced by a gas having a low co-eflicient of heat transmission such as difluorodichloromethane or sulphur dioxide. This gas is supplied from a supply tank or other source 90 through a shut off valve 92 and piping 94 under the control of a pressure in the two supply pipes 98 which extend between the ends of the rollers 88 and the nearest edge heat sealing rollers 121 located upon opposite sides of each edge of the two sheets of

film

62 and 50. Each of the two supply pipes 98 has its end portion extending inwardly between the two sheets of

film

50 and 62 and is turned at right angles in the direction of movement as shown in FIG. 2 to provide the outlet 123 within the sealed enclosure provided by sealing the edges of the

film

50 and 62. Additional heat sealing and pressing rollers 125 and 127 are provided to insure the proper sealing of the edges of the film so as to prevent the egress of air and the escape of the gas having a lower coeflicient of heat transfer. The rollers 84 are preferably spring pressed together so as to exclude and press out substantially all of the air. Preferably they are independent of or have a resilient connection with the flanges 88 so that subsantially all the air will be squeezed out.

Below the rollers 127 the films in-between the pieces 34 of insulation are sealed together by a set of flying transverse heat sealers 129 and 131. These transversely seal the film in the space provided between each adjacent piece 34 of the insulation so as to provide a transverse seal ateach end of each piece 34 which cooperates with the seals on each side to constitute a completed bag or sheet enclosure. This makes it possible to fill the insulation space pieces 34 and the entire enclosure between the

film

50 and 62 with the gas from the supply source 96. These heat sealers 129 and 131 are mounted upon a movable frame 133 which is reciprocated through the connecting rod 135 and eccentric drive 137 driven through the transmission 139 also by the electric motor 74. The heat sealers 129 and 131. are moved into position when the frame 133 is moving with the films 511 and 62 by the air cylinders 141 and 143 mounted upon the framework 133 and connected by the pipes 145 and 147 to the supply and exhaust air pressure pipes 149 and 151 which extend from the control valve of 153 having an actuator 155 which is operated by projections 157 and 159 upon the eccentric drive 137 so that the air cylinders 141 and 143 are operated at the exact time that the movement of the frame 133 is synchronized with the movement of the

film

50 and 62.

Below the heat sealers 131 the entire outer surface of the film 5t) and 62 enclosing the pieces 34 is sprayed from the spray nozzles 161 and 163 with a mixture of materials forming a flexible closed cell foam polymer preferably containing in the cells a gas having a low coefficient of heat transmission. Preferably the foam is of the polyurethane type. As one specific example of materials forming a flexible closed cell substantially impervious foam polymer there is supplied through the conduit 165 the component A in parts by weight consisting of a mixture of 44 parts of toluene diisocyanate and 15 parts by weight of monofluorotrichloromethane. The toluene diisocyanate consists of a mixture of 80 parts of 2,4 toluene diisocyanate and 20 parts of 2,6 toluene diisocyanate. For the second resin component B supplied through the conduit 167 there is provided a mixture in 90 parts by weight consisting of parts of castor oil, 10 parts by weight of distilled tall oil and 3 catalysts including /2 part of n ethyl morpholene, .2 part stannous octoate, 1.0 part of tetramethylguanidine. The resin component also includes surfactant in the amount of 1.5 parts of organosiloxane. This resin component B is supplied through the conduit 167 to the mixer 169 for supply through the conduit 171 to the spray heads 161 and 163 which spray the entire outer surface of the

films

62 and 50 with the components which form the flexible closed cell substantially impervious foam polymer directly adherent to the film to provide a resilient protective coating for the film. The foaming of the components continues under the heat provided by the infrared heaters 173 and 175 provided on opposite sides of the insulation assembly. This heat also cures the foam which provides a complete protective enclosure 1'77 (FIG. 5) completely around the

films

50 and 62. The foam protects the

film

50, 62 from being punctured by external means and in addition seals the film to further prevent the escape of the gas therein having a low coefficient of heat transmission and also to prevent the ingress of air thereto. In addition, it can be cornpressed and can expand to accommodate changes in temperature and atmospheric pressure. The frame 133 also carries the flying transverse cutters 179 which are spaced a proper distance away from the heat sealers 129 and 131 so that the insulation is cut in-between the two heat sealing areas produced by the heat sealers 129 and 131 but spaced one insulation piece 34 below the heat sealers. These flying cutters 179 are synchronized in movement with the movement of the film 51), 62 when they are actuated by the air cylinder 181 also under the control of the valve 153. After being cut, the completed insulation 183 drops onto a conveyor belt (not shown) for transmission to storage or a place of use.

In the second form of the invention the strip of glass fiber or mineral wool or open cell foam 220 is fed from a supply roll 222. It is drawn between two sets of squeezing

rolls

224 and 226 preferably having surfaces of a foamed or solid elastomer. One of the rolls 224 is driven by electric motor 228 which if desired may drive all of the squeezing rollers. The rollers 224 are placed at the entrance of a large enclosed chamber 230 closed by a wall 232. The seals 234 are provided between the wall 232 and the rollers 224 to prevent the escape of the gas within the chamber 230. The

rollers

224 and 226 preferably are spring pressed together to squeeze substantially all of the air out of the strip of pervious or permeable resilient insulation 220. This material expands within the chamber 236 after it passes the rolls 226 and thereby allows the gas within the chamber 230 to penetrate it and fill its voids. The gas supplied from the supply tank 347 preferably is a gas having a low coefiicient of heat transfer and preferably is the same gas as supplied from the tank 90 in the first embodiment. In this second form no film or bag is used to enclose the insulation.

Instead the components forming the resilient closed cell substantially impervious foamed polymer are sprayed directly onto the strip of resilient insulation material 220 after it has absorbed the gas in the chamber 230 and after it has fully reexpanded. This is accomplished by the spray heads 236 and 238 which are supplied from the mixer 246. The mixer 240 is supplied through the conduit 242 with the component A and through the conduit 244 with the resin component B in the same proportions as supplied to the mixer 169 in FIGURE 1. As the strip 220 moves downwardly as it is fed by the squeezing rollers 224, its sides and edges are sprayed with the components issuing from the spray heads 236 and 238 onto its sides and edges to provide a complete flexible foam enclosure for the strip 220.

The foam materials are heated and cured by infrared heat from the

infrared heaters

246 and 248 which surround the strip 220 below the spray heads 236 and 238. At a lower level within the chamber 230 there is provided a spotlight 250 which normally sends a beam of light 252 onto the photocell 254. Whenever the strip 220 moves far enough downwardly to intercept the light beam 252, the photocell 254 initiates the operation of a timer control 256 which controls the

air cylinders

258 and 260 to withdraw the framework 262 to the left through their connections with the floating lever 264 providing the connection between the pistons in the

cylinders

258 and 260 with the framework 262. The

cylinders

258 and 266 are controlled by the

valves

266 and 268 which are preferably of the solenoid type which in turn are controlled by the timer 256. The valve 270 controls the air cylinder 272 which in turn projects the stop 274 to the left beneath the strip 220. The timer 256 then controls the solenoid valve 276 to operate the air cylinder 278 which in turn operates the

cutters

280 and 282 which cut the insulation strip 220 to the proper length.

At the same time the timer 256 operates the solenoid valve 284 to control the pistons in the

air cylinders

286 and 288 to retract the holding plates 290 and 292 away from each other a sufiicient distance to allow the piece of insulation 294 which is cut at the same time by the cutter 280 to drop into position between the plates 292 and 290 and is held upon the stop 274. The timer 256 then operates

cylinders

286 and 288 to move the plates 292 and 290 into position in which it holds the insulation piece 294. The timer 256 then controls the cylinder 272 to withdraw the stop 274. The timer 256 then controls the

cylinders

258 and 260 to move the frame 262 into position placing the spray heads 296 and 298 surrounding and in alignment with the insulation piece 294 for spraying the top and bottom thereof. The spray heads 296 and 298 are provided with the same foam forming components from the mixers 321 and 323 as is supplied by the mixer 169. The mixer 321 is supplied with component A through the conduit 325 and the resin component B through the conduit 327. The mixer 323 is supplied with the component A through the conduit 329 and the resin component B through the conduit 331.

6 Suitable spray heads corresponding to the spray heads 296 and 298 are provided in position to spray all the upright edges of the insulation piece 294 so as to enclose the gas within the insulation piece 294.

After this spraying is completed and the supply to the spray heads is cut off by the timer 256, the timer controls the

cylinders

258 and 260 so as to place the infrared heaters 333 and 335 in alignment with the edges of the insulation piece 294 to supply heat to complete the foaming and the curling of the foam forming materials deposited on the edges of piece 294. After the spray deposited foam material is cured, the timer 256 controls the cylinders 253 and 260 to move the framework 262 to the left out of the path of the insulation piece 294. Thereafter the

cylinders

286 and 288 are operated by the timer 256 to move the plates 290 and 292 away from the piece 294 to allow it to fall through the outlet chamber 337 provided with the sidewalls 339 and 341 as well as the

double trap doors

343 and 345. The

trap doors

343 and 345 are normally spring held in the closed position tightly so that when the insulation piece 294 falls, it will first open and close the upper trap door 343 and then it will push open the lower trap door 345 after the upper trap door 343 has reclosed. The atmosphere within the chamber 236 is charged with the gas having the low coefficient of heat transmission from a storage. tank 347 through the pipe 349 under the control of a shutoff valve 351 and a constant pressure outlet valve 353 which discharges through the pipe 355 into the chamber 230 so as to keep the chamber 230 filled with the gas at a slight pressure. This will supply or replace the gas which is taken out of the chamber in the insulation pieces and also compensates for any leakage at the inlet and the outlet.

The flexible closed cell substantially impervious foam polymer which surrounds the outside of both forms of insulation pieces not only prevents the escape of the gas within the insulation core but it is also an excellent insulation material in itself. It is sufficiently durable and flexible to withstand normal handling and usage in processing and packing and installing in the structure to be insulated. In the first form it effectively prevents the film from being punctured during the later portions of the processing and handling. The flexible polymer also aids in providing a close fit within a confined space, thus eliminating air pockets. It also is sufliciently flexible to permit expansion and contraction of the gas having the low coeflicient of heat transmission under variations in temperature and barometric pressure While preventing its escape or the ingress of air and while preventing the formation of air pockets within such a confined space outside the flexible polymer.

If a more rigid external envelope is desired, a polyetherurethane foam of the closed cell type containing the same insulating gas may be used if desired.

While the embodiments of the present invention as herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. The method of making insulation which includes squeezing out a major portion of the gas in a permeable resilient material containing a gas and replacing said gas with a second gas having better insulating properties as the resilient material reexpands, and while retaining the insulating gas in said resilient material applying a sealing coating completely around said resilient material suificient in amount to seal in the gas having the better insulating properties.

2. The method of making insulation which includes squeezing out a major portion of the gas in a permeable resilient material containing a gas and replacing said gas with a second gas having better insulating properties as the resilient material reexpands, and While retaining the insulating gas in said resilient material applying materials forming a closed cell foamed polymer completely around said resilient material suflicient in amount to seal in the gas having the better insulating properties.

3. The method of making insulation which includes squeezing out a major portion of the gas in a permable resilient material containing a gas and replacing said gas with a second gas having better insulating properties as the resilient material reexpands, and while retaining the insulating gas in said resilient material applying materials forming a closed cell foamed polymer also containing a gas having good insulating properties completely around said resilient material sufficient in thickness to seal in the gas having the better insulating properties.

4. The method of making insulation which includes applying a sheet of a flexible material to a resilient insulating material containing a gas, squeezing a major portion of the gas out of said insulating material and replacing the gas with a second gas having better insulating properties, and sealing said sheet of flexible material to completely enclose said insulating material to keep the second gas in the insulating material and to exclude other fluids.

5. The method of making insulation which includes applying a sheet of a flexible material to a resilient insulating material containing a gas, squeezing a major portion of the gas out of said insulating material and replacing the gas with a second gas having better insulating properties, and sealing said sheet of flexible material to completely enclose said insulating material to keep the second gas in the insulating material and to exclude other fluids, and applying to the completed sheet enclosure materials forming a closed cell foamed polymer.

6. The method of making insulation which includes applying a sheet of a flexible material to a resilient insulating material containing a gas, squeezing a major portion of the gas out of said insulating material and replacing the gas with a second gas having better insulating properties, and-sealing said sheet of flexible material to completely enclose said insulating material to keep the second gas in the insulating material and to exclude other fluids, and applying to the completed sheet enclosure materials forming a closed cell foamed polymer also containing a gas having good insulating properties.

7. The method of making insulation which includes feeding a strip of resilient insulating material containing a gas, squeezing the insulating material as it is fed to squeeze out a major portion of said gas, introducing into the insulating material as it reexpands a second gas having better insulating qualities, applying to the insulating material after reexpansion materials forming a closed cell foamed polymer suflicient in amount to seal in the second gas, cutting the strip into lengths, and applying to the cut portions of the strip materials forming a closed cell polymer suflicient in amount to complete the scaling in of the second gas.

8. The method of making insulation which includes feeding a strip of insulating material containing a gas, applying sheet material to opposite faces of said strip, squeezing the sheet and insulating material to squeeze out a major portion of the gas and sealing edge portions of the sheet, introducing into said insulating material a second gas having better insulating qualities as said insulating material reexpands to charge the interior of the enclosure provided by the sheet material with said second gas, transversely sealing the sheet material as spaced intervals and cutting the sheet material at the locations where the sheet is transversely sealed.

9. The method of making insulation which includes feeding a strip of insulating material containing a gas, applying sheet material to opposite faces of said strip, squeezing the sheet and insulating material to squeeze out a major portion of the gas and sealing edge portions of the sheet, introducing into said insulating material a second gas having better insulating qualities as said insulating material reex'pands to charge the interior of the enclosure provided by the sheet material with said second gas, applying to the exterior of the sheet materials forming a closed cell foamed polymer which is substantially impervious to said second gas, transversely sealing the sheet material at spaced intervals and cutting the sheet material at the locations where the sheetis transversely sealed.

10. Apparatus for making resilient insulation containing a gas having good insulating properties which includes means for squeezing a first gas out of resilient insulation and then reducing the squeezing of the insulation, means for introducing a second gas having better insulating properties into the insulation as the squeezing is reduced, and means for applying liquid foam forming materials around said resilient insulation to seal in the second gas within the resilient insulation.

11. Apparatus for making resilient insulation containing a gas having good insulating properties which includes means for squeezing a first gas out of resilient insulation and then reducing the squeezing of the insulation, means for introducing a second gas having better insulating properties into the insulation as the squeezing is reduced, means for enclosing said resilient insulation in a bag, means for sealing the bag, and means for coating the bag with liquid foam forming materials.

12. The method of making insulation which includes applying protector sheeting to the opposite sides of a permeable resilient material, squeezing the protector sheeting together to squeeze out a major portion of the gas from the resilient material containing the gas and replacing the gas squeezed out by a second gas having better insulating properties as the resilient material reexpands, and while retaining the second gas in said resilient material applying a sealing coating completely around said protector sheeting and resilient material.

13. The method of making insulation which includes applying protector sheeting to the opposite sides of a permeable resilient material, squeezing the protector sheeting together to squeeze out a major portion of the gas from the resilient material containing the gas and replacing the gas squeezed out by a second gas having better insulating properties as the resilient material reexpands, and While retaining the second gas in said resilient material enclosing said protector sheeting and resilient material in a sheet material and sealing said sheet material.

14. The method of making insulation which includes applying protector sheeting to the opposite sides of a permeable resilient material, squeezing the protector sheeting together to squeeze out a major portion of the gas from the resilient material containing the gas and replacing the gas squeezed out by a second gas having better insulating properties as the resilient material reexpands, and while retaining the second gas in said resilient material enclosing said protector sheeting and resilient material in a sheet material and sealing the sheet material, and then applying to the exterior of the sheet material materials forming a closed cell foamed polymer.

References Cited by the Examiner UNITED STATES PATENTS 543,964 8/95 Michell 154-451 1,637,547 8/27 Brown 154-45.l 1,978,041 10/34 Dodge 156-79 2,244,097 6/41 Burkart 156-281 XR 2,599,625 6/52 Gilman 156-383 2,863,179 12/58 Gaugler 161-407 XR 2,879,197 3/59 Muskat et al. 156-79 2,955,971 10/60 Irwin 156-79 3,004,877 10/61 Simms 156-145 XR 3,009,298 11/61 Gerlach et al. 53-22 EARL M. BERGERT, Primary Examiner.

Claims

1. THE METHOD OF MAKING INSULATION WHICH INCLUDES SQUEEZING OUT A MAJOR PORTION OF THE GAS IN A PERMEABLE RESILIENT MATERIAL CONTAINING A GAS AND REPLACING SAID GAS WITH A SECOND GAS HAVING BETTER INSULATING PROPERTIES AS THE RESILIENT MATERIAL REEXPANDS, AND WHILE RETAINING THE INSULATING GAS IN SAID RESILIENT MATERIAL APPLYING A SEALING COATING COMPLETELY AROUND SAID RESILIENT MATERIAL SUFFICIENT IN AMOUNT TO SEAL IN THE GAS HAVING THE BETTER INSULATING PROPERTIES.