US2012805A - Process of making insulation board - Google Patents

Description

Aug. 27, 19 35. A. G. BROWN ET AL 7 PROCESS OF MAKING INSULATION BOARD STe hQn E. MPmm Aug. 27, 1935. A. G. BROWN ET AL PROCESS OF MAKING INSULATION BOARD Original Filed Jan. 25. 1932 2 Sheets-Sheet 2 cnTors 1'0 n fierhen ELWPQITBB Patented Aug. 27, 1935 UNITED STATES PROCESS OF MAKING INSULATION BOARD, i,

I Alfred G. Brown, Los Angeles, Calif., and Stephen E, McPartlin, Chicago, Ill;

Refiled for application Serial No. 588,538, January 25,1932. This application November 28,

1934, Serial No. 755,216

7 Claims. (CI. 18-48) This invention relates to memo-insulation material .and the process of making the same and is refiled for an .abandoned application by the same'inventors filedJanuary25, 1932, Serial Y .No. 588,538. The specific form of the product made'in accordance with this invention isa so: called self-sustaining insulating material in slab or board form having considerable rigidity.

Previous methods of producing analogous .materials made from fibers necessitated cooking the raw fibrous materials 'and washing or hearing and mixing the material in, large quantities of water, then assembling the material in a machine or in molds and subsequently putting the formed material through a'drying process. The presentinvention does not involve cookingor moistening the fibrous material and therefore eliminates both the steps of cooking and moistoning and also drying which were necessary in the previouslyknown methods. i

The. present invention provides a selfsustaining insulating material which is extremely light v in weight, water-proof and which has ahigh thermo-insulating efiiciency. The production is manufacture'd from a fibrous material such as preferably rice straw or rye straw or a mixture of the two, such containingpractically no food value and being a waste product and therefore composition applied during the manufacturing process and the fibers are entwined during the heat is applied and when cooled the asphalt coating serves as 'an adhesive to rigidly join the fibers in their entwined condition; thus producing many air cells in the structure of the" product outside of the air cells in the fibers themselves which have been sealed by the asphalt coating.

The invention conceives a novel method of manufacture which involves shredding straw into its fine component fibers, heating thefibrous mass to remove the commercial moisture therefrom, applying a coating ,of water-proof asphalt composition to the fiber while it is-thus heated and dried, formingthe fibers into fiat board like shape and congealing the asphalt coating by cooling to retain the shape and consistency of the produce all of which is performed in, a most efiicient and economical manner and by machinery of relatively.,.low cost which minimizes the cost of the product. a

The inventionprovides various other new and useful features hereinafter more spcifically de scribed and particularly pointed-out in the claims,

reference beinghad to the'accompanying drawings, in which, Figs. 1 and 2 are respectively the forward and rear portions of a. machine adapted to perform the process of manufacture embodying the pres! ent invention, said machine being shown in diagrammatic form and'the'said figures being con sidered-ascomponents of each other. I

Fig. 3 is a transverse sectional'elevation on the line 33 of Fig.2, and i v Fig. 4v is a perspective 'viewof a section of the finished product.

Like reference numbers refer to like parts in allthe figures. r,

The fibrous material. from which the present insulating productis to .be made is preferably straw such as rice straw or rye; straw which is usually obtained in bale form, which bales l are placed upon a feeding'conveyor 2 which conveys the bales, usually "formed in sections la, to a.

separator having a lower moving table 3 and an upper separating belt 4. The table 3, which may be in the form of an endless conveyor, is provided with spikes 3a and moves at a relatively slow speed while the separator :4, which may be of similar construction having spikes 4a, moves at a faster speed thus separating the straw in the sections Ia of the bale, loosening it and moving'it forward from where it enters-between two sets of feeding rollers 5 and 6.

j The feeding rollers 5 and 6 deliver theloosened straw into the picker or shredding machine which; comprises a rapidly rotating drum 1 having teeth or spikes la projecting from its cylindrical surface and an arcuate member 8 having teeth or spikes 8a projecting from its inner curved sur-' face. The member 8 partially surroundsthe cy I fine component elongated fibers. It maybehere stated that the member 8 is adjustable relative to the drum and'that the actual picker machine which ishere shown in diagram "only'embodies Various details of construction whichwill enable. it toefficiently perform its function, the said'ma a temperature at which it will flow freely and is chine in detail being the subject of another proposed patent application not yet filed.

After the straw has been shredded into fibers the fibers are deposited. in a conveyor 9 which is in the nature of a blow-pipe and it is intended that the air current developed by rotation of the drum 1 and directed from itsv periphery will be of sufficient force to carry the fibers designated as ill through saidi'blow-pipe conveyor upwardly where they are deposited through a device commonly known asa cyclone separator.| l atthe top of a bin l2 and the fibers then dropped by gravity into said bin. It is conceived that additional air current to carry the fibers through the conveyor pipe 9 may be supplied from a suitable source if. necessary or another type of conveyor may be substituted for the blow-pipe if desired.

The bin 12 is preferably of considerable capacity and has an appreciable bottom area which is heatedby means hereafter described and the heat radiating from the bottom of 'thebin serves to heatthe contents thereof and particularly the. fiber closest to the bottomwhich heat drives jofi the commercial-moisture of the fiber, which has been found to be approximately 9% of the original weight, this moisture being dissipated upwardlyand emitted from the bin through its open top. a 1

A conveyor comprising a horizontal shaft 13' upon which are mounted a'plurality of paddles l l inclined relative to the axis of the shaft is located with one of its ends extending into the bottom portion of the bin l2 and projecting tl1ere' a location where thefiber is still in its heated and dry condition and has not come in contact with outside atmosphere the asphalt coating material is applied through a feed pipe l8 which obtains its supply from a heated reservoir 89 pro vided with a suitable burner 29 by means'of which heat is supplied. The asphalt coating substance is preferably a blended mixture of 'asphalts of relatively. high and low melting points one of which may melt at approximately 230 F. while the other at F., to which is preferably'added a small quantity, about 2 of the whole, of'crude petroleum-oil; This coating material is heated to deposited in the properquantity' onto the fiber H! as it is-passedthrough the trough I 5 by the conveyor;- The trough I5 is heatedas hereafter de. scribed and is of considerable length sothat the paddles! of theconveyor while acting to move the fibers to which the asphalt coating has been applied will also thoroughly agitate and mix the mass during its travel through-the trough and assure .complete coatingof all of the fibers with the coating material. I

At the. termination of the trough IS a slightly restricted passage 2| is formed through which the coated fibers are forced by action of the, con-.

veyor. .and somewhat compressed in passing through the restricted passageifrom which vthey enter a tamping chamber 22- in which reciprocates a tamper 23 The tamper'23 may be moved by any suitableimechanismsuch as a crank 24 which is driven by desirable means and the speed of the crank and the accompanying reciproca tion of the tamper 23 may be varied relative to the speed of the conveyor shaft l3 with the result that the solidity of the mass compressed by the tamper may be varied.

The tamping chamber 22 emerges at its lower end into. a forming and pressure chamber 25 which has a rigid bottom'ZS and'a top formed by a plate 21 hinged at the entrance side and supported at the outlet side by a turn-buckle 28,

which turn-buckle may be adjusted to regulate the position of the movable edge of the plate 21 and thus govern the vertical dimension of the outlet side of the compression chamber 25.

A lower conveyor belt 29, passing over pulleys 3i! and also over supporting rollers 3i, traverses a horizontal planefrom a location immediately following the outlet side of the compression chamber 25 and receives the material emitted from said compression chamber in the form of a continuous flat strip. Two pressure rollers 32 and 33 are located one above the other with their peripheries in spaced relation, the lower roller i 32 being located intermediate the length of the It is desirable to apply a paper covering to the upper and lower surface of the material, which papercovering is supported from rolls 3? and 38, said paper traveling upon the surfaces of the respective. belts 29 and 3A and coming in contact with the material and adhering thereto as the material passes between the belts. After leaving.

the belts 29 and 34 the material with its paper covering is passed between upper and lower series of retaining rollers 3 5l-and 40 which are located in atmosphere at room temperature which permits the material to cool while being passed between said rollers.

The portions of. the device in which the fiber is coated, mixed, conveyed, tamped and formed are heated by suitable means such as a burner 4! 7 located beneath a bafile plate 42 and the heated air. therefrom is directed around the compression chamber 25 and the'rollers 32 and 33 a small portion of..it being emitted through a stack 43 causing. a constant flow of highly heated air around the-said parts and the remainder of the heated air flows toward the forward part of the machine contactingythebottomand sides of the trough l5 and heating thebottom of the bin l2. Afterserving its purpose the heated air is emitted through a vertical stack 44 which stack is preferably located in contact with a vertical side of the bin l2 and a stack 45 which carries away hot gases from the burner 20 is preferably located adjacent the opposite side ofthe bin l2 thereby supplying heat to aidin dissipation of moisture from the Operation The raw material from which the fibers are obtained is fed into the separator by the conveyor! and as previously stated, this raw material is preferably" rice straw. Rye straw approximate's rice straw i n "desirable quality and may be substituted entirely therefor" or a mix-1 The straw, which has been matted and ,com-

pressed in bales, enters the separatingdevice come prising the slowly moving table or conveyor 3 and the more rapidly moving belt 4 which loosen the straw and feed it in .its loosenedicondition between the sets of feed rollers 5 and 6 from where it is delivered against theperiphery of the rapidly rotating drum 1 of thepicker device. The teeth on the surface of the picker, coacting withthe teeth of the stationary arcshapedmembeer 8, pull the straws into longitudinal position and shred them lengthwise into'their component fine fibers, the picker being designed and acting to break the straw and fibers aslittle' as possible.

After the straw has thus been shredded into fibers, the fibers are deposited in the bin. l2 ,by

means of the blow-pipe conveyor 9 or other 'suitaserves to drive off by evaporation the commercial moisture contained in the fibers which amounts I to approximately 9% of the weight thereof, the

evaporated moisture being exhausted from the open topof the bin. v V v The fibers thus substantially dried and heated are removed from the lower partof the bottom of the bin adjacent its heatedbottom by the combined conveyor and mixer immediately after leaving the bin and while dry and heated and before being exposed to normal atmosphere. a coating substance is applied to the fibers. The coating substance is preferably an asphalt composition which solidifies at normal temperatures and which has been heated sufiiciently tocause it to flow readily. The coating material is supplied through the pipe l8 and its volume or rate offlow may be controlled by a valve lSa in the pipe. The fibers with the heated, fluid coating mate-. rial are conveyed through the trough I5 by rotation of the shaft I3 with its paddles l4 thereon, the said paddles serving to gradually move the fibers forwardly in the trough and at the same time thoroughly agitate the fibrous mass which has been mixed with the coating material so that during travel through thetrough each of the fibers is certain to obtain a thorough covering of the coating material. The trough is heated and its contents are maintained in heated condition during the conveying and agitating process to prevent congealing of the coating material.

After the fibers and coating material have been thoroughly mixed they are ejected from the troughinto the slightly restricted passage 2| compression chamber 25 where the mass is fur-' ther compressed, the amount of such compression depending upon adjustment of the'top plate 21 and the vertical dimension of the outlet-opening between the plate 21 andthe fixed plate 26 and this vertical dimension issubstantially the thickness of the finished product.

Itmay here beexplained that the densityv of the finished product or the amount of compression to whichit is submitted is not governed entirely byadjustment of the plate 2! but is also regulated by the'speed of the conveying device relative to the speed of .the tamper. If the conveying. device is run at a'relatively high speed,

which will causeaa considerable amount of the were. fed between each of the tamp-ers reciprocations and this greater compactness of the substance is carried. on through the compression chamber and the resulting product will, be relatively dense in texture. r

The compressed material of substantially uni-.

form thickness emitted from the compression chamber is deposited upon the conveyor belt '29 over which is spread the'paper supplied by the roll 3'! which paper serves as a covering for one side of the finished product and immediately thereafter thematerial passes under the belt 34 which likewise has been supplied with paper from vthejroll 38 and this paper serves as a cover for the opposite side of the finished product. While passing between the belts 29 and 34, the material is submitted 'to a slight further compression as it passes between the rolls 32 and 33 which serves more in thenature of a finishing pressure than to actually increase the density of; the prodnot and the thickness of the product is accurately regulated by said rolls. i

Following the rolls 32 and 33 the material continues between the belts 29 and 34, which are supported by the rollers 3| and'36, and afterleav- Thematerial continues between said cooling rollers for a distance sufficient to permit the asphalt coating substance to congeal and permanently secure the mass in rigid board-like form and the continuous strip of material emerging from the machine is cut off by suitable means thanlcouldibe effectively produced by a single set of the devices mentioned and thereforesaid de-' vices may be duplicated side by side in numbers" sufiicient to produce a board of desired width '6 tively narrow width. However, the I ordinary' commercial product would be of width greater and in actual practice the number of sets of the device will be varied in accordance with the width of the product to be made.

The product thus formed is in the nature of a slab or board of desirable width and thickness, both of which dimensions may be altered as desired and the article has considerable rigidity which makes it of the self-sustaining class.

The substance comprising the board consists of innumerable fibers,eacli of whlchz'contains' its natural air cells, the moisturehaving beensubstantially removed therefrom "and the fibers all thoroughly coated with a water-proof asphalt composition so that the air cells in each of the fibers have been thoroughly sealed and the fibers areimpervious to moisture. The structure also contains innumerable air cells formed between the fibers which are interlaced in a manner to form such air cells and the same-coating substance'when cool joins the fibers to each other by its adhesive quality and also effectively seals the air cells or spaces between the fibers making them also substantially impervious to moisture. The solidified coating forms the'whole mass into a rigid structure and also serves to adhere the paper covering; to its respectivebroadsides.

Thus the product constitutes a water-proof material of high thermo-insulating value, the sealed air cells in the structure combined with the noninsulating substance of analogous quality.

The machine involved in manufacturing the product in'accordance with this invention is relatively simple and inexpensive as compared with the machinery necessary. to manufacture other thermo-insulating materialsof analogous qualities and therefore the cost of the product is very greatly reduced. 7

The invention is defined in the appended claims and is to be considered comprehensive of all forms of structure coming within their scope We claim: I

1. The process of makinginsulating material comprising, depositing a mass of separated fibers in a container which is heatedsuificiently to dissipate the commercial moisture in the fibers, conveying said fibers from said container while in dried state through a heated conveyonapplying a heated coating material to said fibers in said conveyor, said coating material being liquid while heated andsolid at ordinary temperatures, agitating'said mass of fibers and coating material in said conveyor sufiiciently to cause such fiber to be come coated with said coating material, intermittently subjecting said agitated mass to pressure,

and then gradually applying pressure thereto while said coatingmaterial hardens.

2. The process of making insulating material comprising, providing a quantity of separated fibers, conveyingsaid fibersalong a heated con each fiber to'become coated with said coating ma-' terial, intermittently subjecting said agitated irregularly to one another, and then forcing the fiber massso coatedinto a product of desired shape.

4. The process of manufacturing comprising, providing a quantity of separated fibers, applying coating and adhesive material to said fibers, mixing the fibers so that the fibers are located angularly to each other whereby a relatively great percentage of voids is attained, and then subjecting the mixture to pressure of predetermined intensity to reduce the percentage of voids as desired.

5. The process of making insulating board or the like comprising, confining and heating a mass of separated fibers of straw to a temperature at which ordinary commercial moisture therein will be dissipated, applying water-proof coating material to said fibers while in their dried state, bending and then forming the fiber mass'so coated into a product of desired shape.

6. The process of making an insulating material comprising, heating a mass of separated fibers to a temperature at'which the moisture therein will be dissipated, maintaining the same against contact with cold air, applying the asphalt composition coating to said fibers while in such dried and heated state, said coating'material being water-proof and solidified at ordinary temperatures and being applied to said fibers while heated sufficiently to be liquid, mixing the fibers so as to cause an appreciable size in their bulk and finally forming said mass of coated fibers into a product of desired shapewhile in heated condition and cooling said formed mass to permit said coating material to solidify and thereby retain the mass in desired form.

'7. The process of making insulating material comprising, shredding a fibrous straw material into its component individual fibers, submitting said separated fibers to heat'suificient to dissipate the commercial moisture therefrom, applying a heated water-proof adhesive coating material to said fibers while they are in dried and heated state, agitatingsaid fibersunder a minimum of pressure, said coating material being fluid when heat ed and solid at normal temperatures, and said coating material bein'g-applied in a manner to thoroughly coat each separate fiber and then forming the coated fibrous mass into desired shape.

ALFRED G.' BROWN. STEPHEN E. McPAR'I'LIN.

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