US1461337A - Wall board - Google Patents

Description

I H. F. WEISS Y WALL BOARD Filed Feb. 26. 1919 ammo mama July I'd-" 1923.

WITED!YSTAFTE.S I

.nown'an Emma: wmss, or mmson, Wisconsin, assreiton 'ro'c. seesaw moaaroms, ormmson, isconsin, a coaroaa'rron or Wiscons n.

WALL 30am).

-- Application tiled 1 ebrnary'26, 1919. Serial No. 219,283.

Toalt 'whomit concern:

Be it known that I, HOWARD a citizen of the United States, resldmg at Madison, in the countyrof Dane, State of v and use the same. 7

Wisconsin, have invented certain new and useful Im rovements in Wall Boards; and I do here y declare the. following to be 'a full, clear, and exact description of the invention, such as .will enable others skilled in the art to which it appertains tomake This invention relates to composite boards, and involves, as an article of manufacture, a new and improved composite board, as well as a new method of making composite board. 7 v

. Composite board is extensively .used as a building material by nailing or tacking it directly to the studding'- of a room, so that it may serve in place of lath and plaster as the inner wall-of the room, being ornamented with paint or the like as de'-. sired. Because of the very extensive field for composite board as a building material,

it is usually designated in the trade as wall board.

The method in general practice, at the resent time, of making wall board consists in beating wood fiber in water, and running this fiber while suspended in water over a paper machine, thus forming asheet of paper similar to cardboard. -Several sheetsof this heavy paper are then glued together with a binder of some sort, usually sodium silicate, until a composite board of the desired thickness is built up. Although this is the usual method of manufacture, there are on the market to-day composite boards which differ therefrom in certain re-' spects, but so far as I- am aware, all of these composite boards require that the fiber used be first reduced to a pulp, and as this pulp is mixed'in water, it must be pressed and the water evaporated from the pulp before the board can be made.

The present invention contemplates a new method of manufacturing composite board in which the fibrous or like material is not reduced to apulp with. water, but, on the contrary, is present throughout the process in a substantially dry and solid form. In

accordance with the method of the invention, a mixture of fibrous material and a' bindingagent while in a substantially dry.

may use paper pulp or pul sired shape by compression, and then heated material and binding a out are preferably mixed in a shredder w ich pulverizes the binderandshreds the fibrous material into amass intimately mixedwith small particles of binder. -As the fibrous material, I may use wood waste in the form of shav'- ingssaW-dust, chips, cork or the like, or I screenings or similar fibrous, material. s the binding agent, I may use solid coal tar pitch, as-' phalt,,or any other suitable binding material. The fibrous material is substantially dry, preferably containing 10% or less of moisture. The fibrous material and binding agent are each placed in the shredder, or other suitable mixingmachine, in a substantially dry andsolid condition, and the shredding or mixing operation produces an intimate mechanical admixture of the two materials and at the same time shreds the woody material and breaks up the binding agent. I

After the shredding and -'mixing opera-- tion, the mixture of fibrous material and binding agent is preferably screened, in

order to separate the particles which are still in too coarse a condition for the subse-.

quent operations. The coarse particles from this screening operation may be returned to the shredder. The material pass ing through the screen has been suitably pulverized and shredded, and, in accordance with the invention, is conveyed to a vibrating screen which sifts the mixture to a moving belt or other suitable receiver. This deposition of the mixed fiber and mixture is therebysqueezed into a compact mass, which is now in board form. The thus compacted mass is then heated b passing it into a hot chamber or througli eat ing' rolls until the binder softens, but at a temperature which will cause no distillation of the fiber. have obtained goodre,

sults by matel 250 After the board has thus been eated to soften the binding agent, it is again compressed, referably between rolls, until the desired t 'ckness is obtained,

after which it is allowed to cool in the air,

1 In Fig. 1 of the accompanying drawings,

- passes onto a conveyor 14 within a heating.

and can then be cut to any desired dimension.

there is diagrammatically illustrated an arrangement of apparatus for carrying out the method of the present invention as 'a con tinuous process;

Figs. 2 and 3 of the drawings illustrate one form of the improved composlte board through a conduit 9 by a fan 10 into a storage bin II. From the storage bin the suitably prepared mixture of fiber and binder is fed on to the vibrating screen 12, from 'whence it is deposited on to a belt or conveyor 13. When a layer offiber and binder of suitable depth has-been obtained, it is passed through the compression r01ls.19

which squeeze it into a compact mass of board-like form. The compact mass then chamber 15, wherein a suflicient temperature is maintained, as, for example, by means of heating pipes 16, to soften the binding-agent. Upon emerging from the heating chamber 15 the board passes through compression rolls 17, whereby it is compressed to the desired thickness. The board now passes to the cool 'ing table and conveyor 18, after which it may be cut into the desired sizes. The apparatus illustrated in Fig. 1 is such as to make the manufacture of the composite board a continuous process. Thus, the speed of the conveyor 13 and the amount of material deposited thereon from the vibrating screen 12 may be so proportioned that just the proper depth of material-is deposited on the conveyor during the time that it is beneath the shower of material falling from the screen. It will be observed that thefibrous material and the binding agent are united to form the composite board, by a mechanical compression, while the binding agent is in a softened condition brought about by a suitable application of heat. The board thus comprises a compressed or compact sheet of shredded fibrous material firmly bounded t getherby a binding agent a temperature of approxiis solid at ordinary temperatures.

If desired,- one or both sides of the ini-f proved composite board may be covered with paper orsimilar covering material. This not only adds to the stiffness of the board but also gives a surface which can be painted or otherwise decorated. The covering sheet may be added in any suitable manner, and in Fig. 1 of thedrawings, I have illustrated a-roll of paper 20 which, together with the board while still heated, is fed through the compression rolls 21, whereby the paper is securely stuck to the upper surface of the board. The lower surface of the board may obviously be covered with a similar sheet of pa er. 7

further improved feature of the present invention consists in pressing a series of indentations or pockets into one, or both, surfaces of the board,- while the latter is still warm and in a plastic condition. This feature enables me to make a board which is.

very stiff and rigid but which is' appreciably lighter in weight than when the indentations -or depressions are omitted. Another important feature is that when a board thus indented is surfaced on both sides with a sheet of paper, it has in it a series of dead air cells which increase the resistance of the board to the passage of heat. This feature is desirable and important when the board .is used for the lining of houses and other placeswhere insulation is desired. As illustrated in Fig. 1 of the drawings, the indentations or depressionsmay be made by a pair of rolls 22, arranged intermediate the compression rolls 17 and 21, and provided with projections or protuberances for suitably i11- denting the plastic board as it passes through these rolls. It will of course be understood that the indenting rolls 22 may be dispensed with when it is not desired to employ this feature of the invention.

Figs. 2 and 3 of the drawings illustrate a composite board of the character herein described ha ing the dead air spaces or cells mentioned in the precedin paragraph. The composite board itself, in icated by numeral 25, is a compressed mixture of shredded fibrous material and binder. Each surface of the board represented in Fig. 2 is indent- "ed, thus forming the depressions or pockets 26. The covering sheets 27 of paper, or the like, for each surface of the board enclose the depressions 26, thus forming the dead air spaces or cells referred to hereinbefore.

Instead of covering the composite board with a sheet of paper, or similar material,

one or both surfaces of the board, after it has been heated and pressed, may be coated slate, stone, or similar mineral material, may

, scribed can be sawed and nailed in the same be spread upon the plastic coating. This treatment gives a board which is not only resistant to the weather but has a pleasing and attractive appearance, and is also firei'etardant. Such a board is represented in Fig. 4, where one surface of the board 25' is covered with a layer of pitch 28, upon which is spread a layer of crushed stone 29.

The surface of the composite board may further be coated with a material that will prevent any passage of the binder to the surface of the board. Such coating materials are used in coating saturated felt which is afterwards printed on the surface with various colors to produce floor coverings, etc. After my improved composite board has been coated with such a material, it may be painted any desired color, or finished in a variety of ways.

I have found that by increasing the percentage of binder in the board, so that all of the wood particles are coated with it, a board'can be made which is' very resistant to the absorption of water and to the weather. Consequently, a board thus made can be used for outside construction. I have, furthermore, found that a board made of fiber bound together with an adhesive of pitch or asphalt in the manner herein described, shrinks and expands to a less extent than a board made of ulp formed in water. There is no hydrolyzmg of the fiber, which tends to weaken the same, and make it more susceptible to injury by weather.

An important detail in the manufacture of composite board, such as I have herein described, is the selection of the binding agent. I have secured best results with and prefer to use a binder which has a high melting point (200 F. or over) and a mini:

mum of brittleness. This requirement is found in certain pitches and asphalts. When a binder of this character is used, it is possible to make a board which will remain stifi' at high room temperatures, but will still not be so stifi' at low room temperatures as to be objectionable. In this connection, it is to be noted that pitches and asphalts are cheaper and more durable than rosins.

A board made in the manner herein decomprises shredding fibrous material with a binding agent in a substantially dry and solid condition to produ e l nt ate m xture, forming the dry mixture into a layer of the desired thickness, compressing such layer, heating the same to soften the binding agent, and again compressing to conso idate the mixture into a board of nonhydrolyzed fiber. i 2. The method of manufacturing composite board by a continuous process, which .comprises subjecting a mixture of wood waste and a binding agent in a substantially dry and solid condition to a shredding operation, shaping the mixture into a continuous sheet and heating the same to a sufliciently high temperature to soften the binding agent, subjecting the mixture to compression while the binding agent is still soft, and cooling the article so formed.

3. The method of manufacturing composite board and the like, which comprises mixing fibrous material and a binding agent while in a substantially dry and solid condi tion, depositing said mixture to form a loose layer thereof, subjecting said layer to pressure so as to form a compact sheet of the mixture, subjecting the compact sheet to heat to soften the binding agent, and compressing the compact sheet while the binda ing agent is still soft to produce a board of non-hydrolyzed fiber.

4. A continuous method of manufacturduce a board of non-hydrolyzed fiber, and

cooling the article so formed.

5. The method of manufacturing composite board and the like, which comprises compacting while in a substantially dry and solid condition a mixture of waste wood and a binder, subsequently heatingthe compact mixture to soften said binder, discontinuing the application of heat and then compressing the compact mixture while the binder is still soft. I

6. The method of manufacturing composite board and the like, which comprises compacting into a continuous sheet an in timate mixture of shredded wood waste and pitch in a substantially dry and solid condition whereby to produce a mixture of non-hydrolyzed fiber, heating the compact mixture to soften the pitch, and subjecting themixture to compression while the pitch is still soft.

7. The method offlmanufacturing composite board, which conslsts in forming an intimate mixture of fibrous material witha binding agent while in a substantiall dry and solid condition into a layer of su ficient thickness, heating the layer to soften the binder, and compressing the layer while hot, to form a board of substantially non- -hydrolyzed fiber.

8. The 'method of manufacturing composite board and the like, which comprises heating a substantially dry and solid mixture of fibrous material and a binding a cut to a sufficiently high temperature to so I en the binding agent, subjecting the mixtqre to compression and forming indentations in one or both surfaces therein while the binding agent isstill soft, and cooling, the article so formed.

9. The method of manufacturing composite board and the like, which comprises heating a substantially dry and solid mixture and a binding agent to a sufliciently high temperature to soften the binding agent, subjecting the mixture to compression and forming indentations .in one or both surfaces thereof while the binding agent is still soft, and surfacing the article so formedwith a covering sheet, whereby said indentations form dead air cells.

10. The method of manufacturing com posite board and the like, which comprises treating a mixture of fibrous material and a dry and solid binding agent in a shredder, compacting the mixture thus treated while in. a substantially dry and solid condition,

heating the compact mixture to a sufficiently high temperature to soften the binding agent, subjecting the mixture to compression while the binding agent is still soft, and cooling the article so formed.

11. The method of manufacturing comfiosite board and the like, which com rises eating a suitably shaped mixture of fi rous material and a binding agent for softening the binding agent, passing the heated mixture through com ressionrolls while the binding agent is st1 1 soft, and indenting the .surface of the compressed article to form depressions therein.

12. As an article of manufacture, a composite board comprising a compressed mixture of fibrous material and a bindingagent having surface depressions, and a surface covering enclosing said depressions.

13. As an article of manufacture, a composite board comprising a compressed mixture of fibrous material and a binding agent having a plurality of depressions in one or both surfaces thereof. 7

14. As an article of manufacture, a composite board com rising a compressed sheet of sllllredded woo waste bound together by pltc 1 5. As an article of manufacture, a com- EOSltG board composed of non-hydrolyzed brous material and a fusible binding agent, consolidated by heat and ressure.

In testimony whereof afiix my signature.

HOWARD FREDERICK Weiss.

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