US2208511A - Method of making dense wall panels - Google Patents

Description

4C-z. ELLIS Filed March 11, 1958 INVENTOR. GEORGE h. LL/.S'

llllll ooaoe. Q

k uw s N HJ.: Wnwa 4 ATTORNEY July 16, 1940.l

vMETHOD 0F MAKING kDENSE WALL PANELS hasta .my 16,1940 i 2,208,511

UNITED STATES PATENT A(y1-*Figli *mamon or MAKING nENsn wmvrams George n. Ems, New Brunton, Minn., assigner to vThe Insolite Company, Minneapolis, Minn., a corporation o! Minnesota Application March 11, 1938, Serial No. 195,353

'I Claims. `(Cl. 92-39) 'I'his invention relates generally vto a process head box III and are adapted to contact the formof making hard, dense board, slabs or panels and ing rolls I3 and I4 respectively. particularly to such bodies which have high Sheet I6, formed by rolls I3 and I4, is pa strength both wet and dry and have a small coto a suitable wet press to remove the surplus 5 emcient of expansion in the presence of moisture. moisture. The wet press consists of belts I1 and An object of the invention is to produce in a I8, mounted upon rolls I9, 20, 2I, 22, 24 and 25. shorter time composite bodies or sheets adapted Rolls 23 are for the purpose of maintaining proper for use in construction of building and for various tension on the belts I1 and I8. other uses. The Sheet I6, after having the surplus moisture i Another object of the invention is to provide an removed by the wet press, is passed to a suitably 10 improved process for making board or sheets in constructed dryer. 'Ihe dryer may be single tier which high temperatures are used and the body 0r, if desired, They-be multiple tier- The drier is moved along continuously. consists of upper section 26 and lower section 21.

Another object is the production of bodies of In the upper part of the dryer is located heating l various types from nbrous vegetable material of coils 28 while the heating 1s supplied to the lower 1s any desired length, width and thickness, section by heating coils 29. 'I'he temperature of 'Ihe inventionrelates to the production of hard. the dryer iS preferably around 600 F. to 700 F. stili bodies by rst forming from vegetable brous 0h the Wet 0I receiving end and 300 F'.V to 450 pulp stock a body, removing the surplus moisture F- 0n the discharge 01' dry end.

gd from the body, passing the body through a heater The Sheet l5 may be divided at B after being 20 to remove the moisture, heating the body to raise discharged from the dryer. The moisture conthe temperature thereof with comparatively light tents 0f the sheet as it comes from the dryer may pressure, applying higher temperatures, a rela.- be bone dry but fo!` aneCOnomical operation it iS tively high4 pressure for 9, relatively Short time preferred that the moisture contents be Within 25 and then quickly chilling the hot pressed body. the range of 2 to 10%. 2,. 'I'he last step may be omitted but it Is preferred The dl'y Sheet, Whether bone-dry or air-dry iS that it be used. I passed to a preheating press consisting of sec- Incarrying out the process water-proong mations 3l and 32 in which are mounted heating terial and/or binders may be added but they rolls 33 and 34. 'Ihe temperature maintained in may be omitted if desired and a good product 0bthe preheater presser should be within the range 30 tained, of 400 F. to 500 F., preferably about 425 F.

With the foregoing and other'objects in view Preferably OnlySUrfeee Contact DreSSure iS apthe invention consists of the novel steps and complied irl the preheater Presser.' The board or bination of steps hereinafter more specic'ally deproduct in the preheater has the constituents of' 35 scribed and illustrated in the accmpanyig the vegetable material rendered substantially 35 drawing wherein is shown embodiments of the inplastievention but it is to be'understood that changes, One .01 more Pairs 0f large hOt Pressing rolls, variations and modifications may be resorted to 39 and 0. are DOSitiOhed adjacent the discharge which fall within the scope of claims hereunto end of the preheating press.' The rolls 39 and 40 appended, are heated by any suitable means as for instance 40 In the accompanying drawing: by steam introduced through members 43 and 44. Figure 1 is a vertical-section through an ap- 'Ihe waste steam is withdrawn from rolls 39 and paratus showing a view diagrammatically illusvthrough the medium of conduits 31 and 38. trating such apparatus for making composition The conduits31 and 38 discharge the waste heat 45 boards, sheets or bodies which includes a felting through headers 35 and 36, into the preheater 45 device, a wet press, a high temperature dryer, a press.

heat and hot pressing device. The large pressing rolls 39 and 40 are heated In Figure 1A is a vertical section view of the from 500 F. to 575 F., preferably about 550 F. pressing rolls and chilling rolls. The vegetable material contained in the board at Referring to the drawing in detail, I0 indicates the time it reaches the large rotatable pressing a head box for 'receiving the vegetable brous members is in a highls1 Plastic condition. 'Ihe pulp, II. operatively mounted adjacent the he'ad ,pressure applied by rolls 39 and 40 varies in acbox are forming rolls I 3 and I4 which'pick up cordance with the kind of product desired from the bers and .form them into a continuous sheet. 500# per square inch to 2000# per square inch.

y u Flexible mmbers I2 and I5 are secured to the Generally to obtain a product that has a tensile 55 strength above 6000 pounds per square inch, a pressure of about 1000# per square inch is employed.

The pressed and hot board. 45, may bedivided into suitable lengths by means of cut-off member 46. In the preferred process the board as discharged from the large hot pressing rolls is 'passed between cooling or chilling rolls. The

chilling rolls may be maintained in a cold condition by any suitable means. The hot pressed board which has the temperature quickly brought down below the plastic point of the substance contained in the vegetable material is of greater by mechanical means or'by a relatively light cook ing process.

If desired, material from an extraneoussource such as vegetable oil or material, mineral oils or material, and animal oils may be incorporated in the product to`increase the water resistance. Hydrogenated whale oil in an amount from 1% to 5% has given excellent results and decreases the water absorption about 50% over a product not having the oil incorporated therein. If a material from an extraneous source is incorporated in the product it is preferred that such material have the character of hardening under heat and pressure.

Shouldv Whale oil be used it is generally commingled with the vegetable i'lbers while in a water suspension. The drying of the board to remove substantially all the moisture without pressure preliminarily heat treats the oil which permits of a rapid hardening under heat and pressure. If board-like bodies are to be produced by this process, the time for completing the board is about one-half the time required by known processes. The strength and other qualities of the products produced in accordance with the process hereinbefore described are very muchhigher than any heretofore made.

The surface of the products produced by my process is smooth, highly polished and does not have surface pores that can be detected by the eye. The heat-hardening products of the vegetable material being pressed iiow to the surface of the product and give it a high surface strength and water resistance. 'I'he surface on the products made by my process has great resistance to surface abrasion, in fact, substantially four times the resistance of any known pressed board.

The following is one example for producing board-like bodies: Wood is reduced to pulp by the grindstone method. Three per cent of whale oil is commingled with the pulp while in a water bath by passing the oil and pulp through a Jordan. A thick sheet is formed and the surplus moisture is removed and the sheet is passed to a high temperature dryer where substantially all the moisture is removed or at least has the moisture removed down to an air drycondition. The

dry board is then passed through the preheaterpress, the temperature in the preheater being about 440 F. The board becomes heated throughout and becomes qui-te plastic. The

' rollers or rotatable members compress the board very little as only .surface contactis maintained. The hot board is quickly compressed to its substantial final thickness by the large heated rotatable members. The pressed board is then quickly -chilled by cooling rolls. The sheet, board or product is in continuous motion from the time the product is formed until completed. y

If vegetable oils or mineral water-prooflng materials are incorporated with the pulp. they receive a preliminary heat treatment when the board or product is dried, which permits ofquick hardening under heat and pressure. It is unnecessary when using my process to heat cure the finished product.

It is to be understoodthat variation and modification can be resorted to which fall within the scope of the appended claims.

It is preferred that a portion of the high temperature dryer be provided with top rollsor rotatable members 30'. The moisture of the board at the time the top rolls are applied usually is and should be 'about 30% or lower. The rolls 30', .smooth or iron the surfaces of the board and also result in utilizing that portion of the vegetable material which can be termed water-soluble, hardening material. Such materials harden as the moisture leaves it as is the case of ordinary glue.

The board discharged from the dryer has a substantially smooth surface or surfaces and the water-soluble binder is set. The board discharged from the dryer can be used if high strength smooth surface insulating products are desired. The board or product thus produced has relatively high insulating value and at the same time has higher wet and higher dry strength than any known insulating board. A Y

To obtain a very dense and rigid board, the board or product discharged from the dryer is then passed to the preheater press and subjected to the additional steps as shown by the drawing and hereinbefore described.

The boards discharged from the large heating rolls, 39 and 40, are not permitted to materially cool until they reach the chilling rolls. The chilling of the boards under pressure, results in setting up those parts of the vegetable material that hardenupon cooling. Thus by this method, all the natural cementing materials of the vegetable materials that act asa binder are utilized.

It is possible to use physical condensation products from an extraneous source aswell as chemical condensation products due to the. fact of chilling the hot pressed board. What is intended to be covered by the term physicalcondensation products are binders and/or waterproofing materials that harden by cooling. By `chemical ycon-- densation products, it is intended to covervheat hardening binders vand/or waterproofing.v materials.

The waste heat from the preheater press be..

withdrawn asv at C, and discharged iutoQvtlie ydryer and the waste heat from` the dryerniaybewithdrawn as at D and used v for heatn th""water suspension of the vegetablei ing of the sheet or' bo`a.rd.',lf`

Board produced in accordano has higher surface resistance ,to abrasion, higher' wet strength after soaking -in water for fortywith uns' process eight hours, and vhigher dry strength than any known pressed fiber product.` g

Any vegetable i'lbrous material may be used in the process and it is intended to include woods of various kinds and fibers obtained from annual plants. Whatever kind of wood vor woody material is used, it is preferred that the major portions of the natural cementlngmaterials be in the berlzed Vmaterial when pressure is applied. What I claim is: ,y 1. A process of making. board-like-bodies from raw vegetable fibers which includes commingling approximately 3% of whale oil with fiber in a water suspension, forming a board from the iibers, pressing the sheet to remove the surplus moisture, drying the sheet without pressure to reduce the moisture content to about 30%, thereafter ironing the surface of the board while continuing the drying, then applying surface contact pressure at a temperature of about 400 to 460 F. to `the board having a moisture content from 2 to 10%, thereafter applying pressure of at about 500 pounds per square inch to the dry board at a temperature of about 500 to 575 F., and nally quickly chilling the board to lower the temperature whereby the board is cemented together 'by natural cementing material contained in the iibers.

2. A process of making board-like products from vegetable ber containing substantially all of the natural cernenting materials of the original vegetable material comprising drying a wet boardto 575 F., and thereafter quickly chilling the hot board-like product under pressure'by ,means of rotatable members.

3. A continuous process of making -board-like bodies which comprises forming a board from vegetable fibers in a water suspension, pressing the board to remove the surplus moisture, advancing the board through a dryer, smoothing the surface of the board in the dryer after the moisture content has been reduced to below 30%, then heating the substantially dry boardwhile maintaining surface contact with the moving board by rotatable members'at a temperature above 400 F., applying high pressure to the hot and dry board at a temperature of about 500 to 575 F., and then quickly reducing the temperature of the hot pressed board by passing the board between chilling members.

4. A process of making hard, highly waterresisting, and' dense board-like bodies which includes commingling hydrogenated whale oil with fibers in a water suspension. passing a mixture ofb pulp and oil through a Jordan to substantially uniformly coat the fibers with oil, forming a board, pressing the board to remove the surplus -moisture, drying the board without pressure to reduce the moisture contents, ironing the surfaces of the board. after the moisture contents have been reduced to about 30% while continuing the drying, then heating the board at a temperature of about 400 F. to 500 F. with light surface ,contact pressure, and pressing the hot board ata temperature within the range of 500 to 575 F. at a pressure from 500 to 2000# per square inch.

5. -A process of making hard, dense and highly water-resistant board-like bodies fronr vegetable fibers in a water suspension, commingling a Water-proofing material with the bers, forming a board-like body, removing the surplus moisture, drying the board without pressure, then smoothing the surface of the board during' drying after the moisture has beenreduced to about. 30%, then applying only surface contact pressure at a temperature Within-the range f about 400 F. to

about 500 F., thereafter applying consolidating pressure at a temperature above 500 F. and then quickly chilling the hot board under pressure..

6. A process of making board-like-products including the steps of forming. a felted vboard from vegetable iibrous material in a water suspension, removing the surplus moisture, drying the board to reduce contents to substantially air dry condition, then heating the, board at a temperature of about 400 F. to 500 F. with only surface contact pressure to render the vegetable materialhot and plastic, thereafter applying consolidating pressure at a temperature above 500 F., and then quickly chilling the hot board under pressure.

7. The process of making hard and highly water-resistant board having high tensile strength, including the steps of mixing a water-proofing material with vegetable bers in a water bath, pressing 'a board to reduce the moisture contents, drying the board vand smoothing the surface of the board during drying after the moisture contents have been reduced to about but above 15%, then applying light pressure to the substantially dry board at a temperature of about 400 to 500 F., applying 500 to 2000# per square inch at a. temperature above 500 F. to the hot, dry board, and coldpressing the hot board to quickly reduce the temperature below 212 F.

- l GEORGE Hr ELLIS.

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