US1265655A

US1265655A - Fibrous composition and process for making the same.

Info

Publication number: US1265655A
Application number: US7795316A
Authority: US
Inventors: George A Henderson
Original assignee: Individual
Current assignee: Individual
Priority date: 1916-02-12
Filing date: 1916-02-12
Publication date: 1918-05-07
Anticipated expiration: 1935-05-07

Description

G. A. HENDERSON.

FIBROUS COMPOSITION AND PROCESS FOR MAKING THE SAME.

APPLICATION FILED FEB. 12. I9I6.

Patented May 7,1918

E% PATENT @FFIQE.

FIBBOUS GOM?OSITION AND PROCESS FOR MAKING THE SAME.

To all whom it may concern:

Be it known that I, GEORGE A. HENDER- SON, a citizen of the United States, residing in Highland Villa, at St. Albans, in the county of Kanawha and State of West Virginia, have invented certain new and useful Improvements in Fibrous Compositions and Processes for Making the Same, of which' the following is a clear, full, and exact description.

The invention relates to a new process for rendering woody particles unnatural and restoring them to their initial density and consistencyin a preserved state and to the manner of their incorporation with a preservative-binder in forming building and paving structures of the class referred to in my issued United States Patent No. 1,040,321, of 1912, and my pending applications, Number 874,934, filed November 30, 1914, and Xumber 64,285, filed November 30, 1915. While the latter represent substantial improvement in the art, my present invention is based on my discovery that superior structures are more economically obtainable by substantial departure from the processes heretofore disclosed. Also, while in my former processes I use the waste wood from tannic acid and dye manufacturers, in whose process the wood is denatured, in the present process an incidental object is to reduce to commercial use the great quantity of hardwood heretofore discarded as waste culls of veneer plants, in which the wood is merely softened by water before shearing it into sheets of uniform thickness.

Hereinafter, in relation to this invention, by particles I mean woody particles of not exceeding in uniform thickness, shredded into various lengths and breadths graduating in irregular area aggregating 1" x i" down to the thickness of the particles, the edges of which are beveled, ragged and torn to tatters in being shredded from thesheets of the wood sheared from the log, measured in predetermined quantities of each size in regularly descending gradations from the largest to those approximately a" x forty per cent, those from x "'to the thickness thereof to which is added 10% of particles reduced in size from the greatest thickness to those of dimensions corresponding to the thickness of the ragged edges of the particles, all impalpable dust being entirely eliminated.

Specification of Letters Patent.

Patented May i913.

Application filed February 12, 1918. Serial No. 77,953.

By fibers I mean those longitudinal strands of tougher consistence than the cellular tissue by which they are surrounded in their natural state; by pores I mean those spaces within the wood particles walled by the fibers composing the particle, whether filled or unfilled; by voids I mean spaces or interstices between the separate woody particles; by moisture I mean a quantity of water in excessof that required to maintain the identity of the fibers as such; by normal I refer to the natural state or size of the particles and the natural volume of their pores before abnormal enlargement or other treatment herein referred to; as well as to the consistency and volume of the binding preservative hereinafter described, when cold, and before expanded or subjected to the treatment herein prescribed; by bitumen I mean a compound of pitch, natural or artificial asphalt of bituminous nature used in paving structures, and known to the trade; by penetration I mean the United States standard measure of consistency and density of bitumen as applied to paving structures.

In practice I have discovered that durability of such compositions is increasedvby the present process in which the particles are more completely, efiiciently and economically denatured, ore-expanded, impregnated, contracted, bound and compressed, the graded particles more uniformly mixed and advantageously positioned in the mass, and the impregnating binder more thoroughly and uniformly disseminated throughout the mass by simultaneous accomplishment of these objects, than in the manner disclosed v in the prior art, as distinguished from which the particles are, in the present process, not heated, their sap and pulp not extracted, they are not saturated with water, nor are they expanded, then dried and contracted before impregnation with their preservativebindor. On the contrary these steps are more simplv and effectively taken simultaneously. that of water saturation being entirely eliminated. The destructive distillation of the cellular tissues of the particles, and the expelling of their sap and moisture content. together with maximum expansion of the pores and the consequent development of maximum absorbing efficiency of the particles, results from my employment of extreme heat. above the normal carbonizthe minimum, l have ing point of the bitumen, as well as that oi the wood, sustained throughout such iniprcgnation oi the particles by their binder, and during partial compression of the mass, as and for the purposes hereinafter dcscribed.

l have discovered that such heat, in combination with substantial vacuum created Within the chamber containing it, is essential to sufficient "fluidity of a quantity of bitumen in exccss of that required in the completed product, which excessive quantity is temporarily neediul in my process for the purposes hereinafter described. and that such heat is also essential to provide the required degree of expansion of the particles, and the maximum development of their ahsorhing etiicicncy to insure perfect impregnation of the particles by their binder, as Well as to insure substantial reduction in the latters quantity and consistency, in coinbination with simultaneous fixture of the graded particles in horizontal layers thereof. :tor the purpose or" securing their vertical positions under tratlic at right angle thereto, upon which element alone the life of natural woodblock pavements is recognized to depend.

llhile l appreciate the fact that such heat will result in volatilization oi the essential oils in the bitumen, l have discovered that, as an example, the artificial asphalts adaptable to incorporation with sand and stonev in paving structures, contain a prohibitive quantity of such oils for use wit tvoocy particles, because of my discovery of the fact that to the extent the oily constituent is increased the bonding value of the bitumen is lessened, and that oil will not bind Woody particles, but on the contrary, seriously interferes even with their own me chanical clasp with each other. I have discovered that when surrounded by an excessive quantity of the bitumen. the particles, when inclosed in a vacuous space, Will, even in the presence of such oxygen as is es.- pelled from the decomposing cellular tissue oi particles, (which oxygen is, as quickly as formed, expelled from the chamber) not ignite or carbonize when exposed to as high as 500 degrees Fahn, and that while. it this heat is sustained a sutficient length of time, the preserving and binding value of the bitumen Will be therehy destroyed, yet

' in my process such heat is applied in predetermined degree with especial regard to that required to reduce the oily constituent of the bitumen, and its normal fluidity "from an excess thereo'l to the exact consistency for practical use with Woody particles in the completed product.

in my search for means of retaining essential ductility of bituminous compounds which the oily constituent is reduced to discovered t ne presence of the excessive quantity thereof, when first L lxed with the particles, mar, addition to providing the employed means for avoiding carhonization oi the WOOCl and bitumen hy severe heat, he advanta geously utilized, in combination with such heat, and the steam in evolution, when super-heated. a means "for absorbing pure sulfur, added in practical quantity to the other ingredients of my composition Wniie mixing: thorn; and l have iurther discovered that While in the use of natural sulfur-bearing asphalts, but a comparatively srnall quantity oi pure sulfur should he added to mixture, yet in the use of artificial asphalts the addition of this ingredient results in increased ductility of bitumen thereby made more cementitious in its rela tion to needy particles, and less affectable hy the heat ofsuminer or the cold of Winter than any bituminous compound used for paving of which I have knowledge: provided, however, the excessive quantity of oily constituent is first present to act, under the influence of severe heat, as the absorbing medium or" the sulfur, to be then partially eliminated by volatilization thereof.

in a further modification of my process. and as distinguished from its use in fornr ing paving structures, 1 have also discovered that in any manufacture of Water-prooted building blocks, columns and other substitutes for timbers, in which no bitumen is used, the natural particles contain much,

in addition to their libers, that is practically usable in forming such compositions,viz.. most of the hard-Woods, such as beech. maple, oak and the like, contain a large percentage of pyroligneous acids, which in practice it have separated from the WOOCl by destructive distillation of its cellular tissue, in the manner heretofore described. when combined, as they do, with sulfur, in the presence of the steam expelled from the wood, hydrated sulfuric acid is formed, which, in contact with casein in solution, produces a gummy mass of cernentitious va ue. Because of the simultaneous enlargement of, and the incidental creation of vacua Within the pores of the particles, this substance is absorbed at once by the pores. it then this is done in the presence of approximately 5G0 degrees Fahn, l have discovered that the particles are thoroughly waterproofed, and are ready to be compressed into shape in the manner hereinafter described. ln fact 'i have in practice impregnated the pores of hardwood with a solution oi sulfur and crude pyroligneous acid, and found that the heating thereof, in cacao, to a temperature of approximately 500 degrees ahr., resulted in perfect and permanent Waterproofing oi the Wood.

a further modification of my invention iireprooling solrnfiions any lei-own conneonate sistence may be added before or after the mass is so impregnated.

In a further modification of my invention, the building or paving structures may be reinforced by wire mesh, twisted steel rods, or other reinforcing matter placed within the structure before compression thereof,

It has been heretofore proposed to cause particles in paving aggregates bound with bituminous or other compounds tolie flat on horizontal relation to each other and to the earth, and it has been recognized that if such woody particles could be bound in a preserved state in such manner that only the ends of the fibers could be presented to the action of traiiic, a muchmore durable product would" result from the tendency of the particles tomat under the influence of such wear with less likelihood of disturbing, the bond between the particles touched by traffic than if the fibers were prescnt in the mass in variously inclined positions.

The horizontal fixture of my particles in paving structures is insured by (a) the irregular length and breadth exceeding their uniform thickness, (6) their beveled, tattcred edges, (0) consequently their natural inclination-t0 lie flat in a quantity of fluid of the consistency of water sufiicient to float them until such flat, horizontal positions are assumed, (d) vibratory motion of their container during setting of the particles; (e) together with the action of the severe vacuum within which they are so positioned, and the entire absence of pressure, atmospherically or otherwise, until the mass is mechanically compressed without disturbing the relative location of the particles.

A composition of such particles mixed with bitumen is more practically, than otherwise, compressed to a thickness of only two inches. If greater depth of the product is desired, such increased depth should be formed by layers of the completed product cemented together. structure is of the form of ordinary sheet asphalt, I prefer, for the sake of horizontal or vertical presentation of all the particles to the action of trafiic, as the case may be, to out the material into blocks or slabs 36"x36",

set dodge-fashion, in the one case, and to cut the material into blocks 2"x2"x9" in the other case, and I have discovered that when, before placing, the blocks are painted at their edges with a sufiicient quantity of the same cementing agency as that with which the particles are bound together, the blocks will adhere to each other so intimately, within a short time after being subjected to trafiic, as to form substantially a monolithic pavement, the joints in which are not discernible to the naked eye.

In a modified procedure I mix predetermined percentages of bitumen and normal woody particles of various sizes, such as When the pavementdescribed in my copen application Serial No. 874934, under sustained heat suit ficient to destroy the cellular tissue,- sap and discharge the distillates thereof and moisture from the mixer during development of the absorbing capacity and impregnation of the particles pores by the bitumen and I lay the material on the previously prepared road base hot, gradually cool and contract it, and. then compress the same, during contraction, into a sheet pavement in the mannor in which sheet asphalt is laid,

I have discovered that the popular impression that the hotter, and consequently, the softer the mass is, the denser it canbe compressed, when hot, is entirely erroneous as related to fibrous compositions. Even in mineral compositions mixed with hot bitumen the elements of expansion and contraction of the bitumen itself are not sutliciently guarded against in this regard, whereas with wood fiber, I have discovered that the particles do not reach the limit of their con;

traction until cold, and while heat is essential to render the mass sufiiciently plastic to rake, spread, or otherwise handle in forming a paving structure, it may be, after he ing so formed, compressed preferably when thoroughly cooled to atmospheric temperature, than compressed when hot. i have also discovered that lack of regard for, and

insuiiicient means to avoid the entrapping.

of air and gas bubbles within the mass during compression has been responsible for the prcsence'of a rohibitive volume of voids in the complete product. I have discovered that plunger compression of such material in any other than an open mold is wholly impracticable, while plungcr compression of such material in any mold is ineficient, in that in every case it seals the top and bottom of the mass before releasing the gas and air in its center, or giving a full opportunity to the ingredients to contract from abnormal expansion caused by their heat. I have found that even the to and bottom roller compression. adopted y me as the most practicable, in an open mold, is accompanied by unfavorable elements which are necessarily guarded against in the formation of a perfect product: viz., the tendency of such compression 'of the warm, plastic mass, to increase its sheet area at the sacrifice of vertical density, as well asthe slight inclination of all particles toward one direction. In my process the mass in the first instance is conveyed, independent of the forwarding influence of the rollers, between them, by a foraminated ma inclosed at its surface with an end and sides completing the container for the material; after h sufficiently compressed and cooled the material passes onto a shelf inclosed at its sides, re-

did

cues for forward motion of the sheet bc- 1,2e5,eee I thereof, and Fig. 7 is a side elevation in section of a hydraulic press.

Referring to the drawings by numerals, in carrying out my invention, the wood is sheared into sheets from the log 1 anchored by clamp 1, revolved by pulley l driven by belt 1", the lo being in engagement with fixed knife 2. he sheets 3, of the desired thickness, are deposited into hopper 4 of shredding machine 4, in which the sheets are reduced to particles by shredding mechanism operated by pulley 4 driven by belt 4". The particles are conducted from the shreddin machine through chute 4 and depositef onto screen 5, within which is spread mesh which will permit the passage of particles of the size 1"xi graduating down to those of an average size corresponding with the thickness of the ragged edges of the particles. Screen 5 is slightly inclined from horizontal and is designed to be given a vibratory motion, which will cause the particles which will not pass its mesh to be worked to the top of the screen and deposited into re-shredding machine 6, operated by pulley 6 driven by belt 6, in which these larger particles are cut into smaller sizes and returned to screen 5 by belt conveyer 7 after being deposited through chute 6 into container 7. Screens 5 and 5 preferably contain mesh which will permit of the passage, first, of particles in size f'xf graduating downwardly, and secondly, of particles in size lfx graduating downwardly, those failing to pass screens 5 and 5 being conducted by their inclination from horizontal into measuring boxes 8*, and being in the minority of the mass; those passing screen 5 shall pass screen 5 in major proportion of the mass. and are likewise conducted to measuring box 8 as shown. The particles are then measured in predetermined quantities of each of the several grades from the largest. viz.. -}x3,- by the thickness of the sheets. in regular descending gradations down to the size gxk" 40% thereof; those from %"x{;, to the thickness thereof 50%, while approximately 10% of smaller particles in the mass is secured as a result of adjusting the shredding machine to produce practically this quantity in the shredding of the sheets into particles. The particles are then mixed in the common chute 8, by which they are conducted to a measuring container 11, through which in proportions in relation to that of the impregnatingbinder yet to be referred to, the particles are discharged into mixing apparatus 12, through gate 12". The impregnatingbinder hereinabove described, is preferably heated to sufficient fluidity in kettle 9, measured in predetermined proportion in relation to the proportion of particles, as described, in measuring kettle 10, and discharged through cock 10, simultaneously with the particles, into the mixer 12, through pipe 10", or otherwise. Chamber 12 is nested within oven 13, surrounding substantially three-fourths of the mixin chamber 12, in which oven heat is supplie by a furnace, the heat-from which preferably generated by burning gas, or oil, is conducted by exhaust fan 13 in stack 13, so as to artially surround the inclosed section of the mixer 12, and at the point l3 be sucked into and through the inner chamber of mixer 12, in direct contact with the composition therein being agitated and mixed by the operation of agitating blades 12 anchored to central shaft 12 revolved by pulley 12 driven by belt 12. The mouth of mixer 12 extends from a point in the shell of said mixer extending externally of the oven 13, which mouth 12 is equipped with air-tight gate 14", in housing 14 toward which the material in the mixer 12 is conducted by the peculiar shape of the agitating blades 12 Gate 14 may be operated by hand, care being taken that at least one-fourth of the space within the housing 14 is filled with the material when the gate is turned to admit the material within impregnating chamber 14. If, in accord with the modification of the invention hereinabove described the composition is to be laid in monolithic sheet form and not manufactured into blocks, the material is, at this point deposited through gate 14 onto the previously prepared base of the roadway, but in this event, the material is permitted to remain in drum mixer 12 until the particles have exhausted their absorbing capacity and become impregnated with the bitumen in the manner described. Upon reaching this chamber the mass is dropped onto bafiie plate 14, the first of a series thereof, anchored in an inclined position within chamber 14, to which plates may be attached off-sets which act to turn the mass, and to expose the particles thereof to the heat and vacuum influences within chamber 14 hereinafter described, in the fall of the material from the top of the chamber 14 to its bottom. Between the battle-plates, as shown, endless conveyers 14 operated by cog or sprocket connection with common shaft 14 are revolved on

rollers

14, 14", to which conveyers are attached buckets 14 14 designed to pick up the material at the bottom of the chamber 14, lift it to its top and drop it through the heated vacuum of the chamber, over the baffles 14 to the bottom of the chamber in a sufiicient number of such operations to expose each of the particles to the inflcnce of the heat and vacuum within the chamber 14, hereinafter described, for the purposes hereinabove set forth.

Chamber 14 is preferably constructed of heavy steel, and its lower curvature incnsed Withiniirebriclr 15". ;t is preferably hosted by two turner-es the heat from which converge at its longitudinal center and is exhausted through stuck 15 Chamber 1% is partially nested Within the furnaces 15 15 and shell 15, 15., within which turnaces 15*- sny suitable fuel may be deposited through doors to l? and burned to heat the contents of chamber it to approximately 500 degrees elir. Exhaust stack i l? leading from chamber 1% to condenser 1 is equipped with e powerful exhaust fan M in housing l l designed to create substantial vacuum Within chamber 14. The operation of the shore mechanism, and the subjection ot the ingredients to the influences mentioned, therein, results in the maximum enlargernent of the particles, and expansion of their pores, the complete change in character of the matter theretot'ore forming its sap, cellular tissue and moisture, and in its extrac tion and removal from the particles, the development of maximum absorbing eiiiciency ot the pores, and their complete impregnation with bitumen present and surrounding them in excessive quantity, and also results in the reduction of the oily constituent oi: the bitumen, to render the bitumen of pine ticsl plasticity and binding value in the completed product, as Well as the reduction of the plastic bitumen to a state of extreme fluidity, in which condition it, together with the particles which it surrounds, is deposited Within chamber i l onto endless conveyer 16', which conveyor is forsniinuted and is reyol ed by cog or sprocket Wheel 16 (shown in 8} around drums 16 -46 Conipressor rollers 16 are re ol'ved by the action of their axles extending through the wells or chamber is and oven 15, in air tight bearings, and are anchored in retaining bearings, Within which they revolve, riveted to the inside walls chamber H -While compressor-rollers 16 are adjustable by manipulation in such manner as to regulate the lust pressure gi en'to the mass before emission from chamber 14-, the series of compressions given by all of these rollers, revolving inversely us to conveyor 16", 0t reciprocating size, speed and direction, being designed to express from the abnormally enlarged pores of the heated particle lhe e1; cess quantity of bitumen hereinabore referred to, leaving Within the pores of the particles as they emerge from chamber 1% an insui'hcient quantity of such bitumen to fill there, but sutlicient, in their subsequently contracted state. to completely fill them, to coat them, to till the compressed voids be tween the particles and to bind them to each other. The bitumen expressed in the compression just referred to is precipitated into the bot-torn chernber "ll, inclined downwardly at this point, toward, and is emitted through, outlet pipe 16 for use us a by-prod not. 16 is s men-hole for use in repairing the mechanism Within chamber 1%. space between rollers 16 while norrnslly opened, is completely closed and air-tight by reason of the severe compression orthe mass between the rollers at this point. The

products of distillation, us well as the fumes from the heating bitumen conducted through exhaust pipe l to condenser Where they are entrapped and reclaimed to be subsequently used as lay-products.

For at distance of approximately sir. feet from the innermost end of conveyor 16* the V ioruinineted belt thereof is by proper mechanism, given a cider-rise vibratory motion, the material falling thereupon at this point being inclosed by an end piece and two sides of steel construction, whereupon by such yibrstion and shaking of the conveyor, before tity.

Endless belt 16 extends through the walls of chamber is and oven 15 and beyond and within cooling chamber 17 immediately c joining, in which no host is present other than that arising from the hot mess coir reyed thereinto by conveyor 16. Cooling chamber 17 is also equipped with powerful enhsust an 1'2 operated by pulley 17 in engagement with belt 17, for creating and maintaining "Within chamber 1? substantinl vacuum, to prevent ignition of the hot mass before being surliciently reduced in temperature. Within chamber 1'? the moss is further compressed by rollers 1'? Without disturbance of the relative positions of the psrtic es Within it, and the material is de signed to remain Within said chamber 17,

in its course through it, a sufiicient length of time to reduce the temperature to approxiinst-ely 200 Feband the depth of the mess to approximately ll before emission through its mouth 17 which is closed by the passage of riatericl therethrough in being: compressed at that point to the thickness of approximately l.

ll hereupon compression continues, at at niospheric temperature, by a continuation of endless belt 16 through two sided trough 18, and reciprocating rollers 18 18 which serve to reduce the thiclrness to approximutely 3-5; by the time the mess is it proximately 150 degr es l ehri, when the point 18* the forsniineted conveyor turns on drurn 16 leading toward chamber 14. Referring to the enlarged detail, Fig. 8, 18 designates a stationary trough of preferably steel construction, immediately next to the inversely operating rollers 18 18 intervening between endless conveyer 16 and trough 18. The material being conducted to the rollers 18 by the operation of endless conveyer 16", is of sufficient solidity to bond its particles together to be pulled through and between rollers 18 by their revolving action, much the same as a cloth is pulled through the space intervening between the rollers of a clothes Wringer. Rollers 18 are of exactly the same circumference, revolved by the mechanism more in detail shown in Fig. 7, in which 18 designates the sides to the trough, 18 the rollers referred to, 18 cog wheels which mesh with each other in reciprocating action, driven by bevel cogs 18 18 connected with suitable power. Longitudinally of the rollers 18* a knifelike blade 18 extends the length thereof, and is preferably of heavy construction, eX tending at right angles to the center of the rollers 15 in depth. Rollers 18 are each preferably 36 in circumference and are so revolved that the knives 18 18 will converge as they pass each other not more than apart in cutting the sheet as it passes through the rollers 18 which are designed to further compress the material from 3% to 3" in depth. The material when first compressed in chamber 14 is designed to be retained by the two sides of the trough containing conveyer 16*, which two sides are 36 apart, so that the blocks when first cut by the knives 18 shall be of the size 36X36x3". By the pressure of material behind them the blocks are pushed forward on trough 18 until they reach a conveyer passing between compression rollers revolved in a direction at right angles to rollers 18, which conveyer is designed to move in a direction at right angles to trough 18, in which latter operation the blocks are further compressed to approximately 2% in thickness and at the same time are cut as in the former manner described to a size 18"x36. The blocks are then conveyed to an endless conveyer which moves them in the reverse direction to that in which they were conducted when first cut into blocks, and are in this operation again cut into sizes 18x9 inches and compressed to approximately 2% in thickness. The blocks, while still retained in a trough 36 wide, but therein fitted together, are rolled in a direction the reverse to that in which they were conveyed when out the second time. and then compressed to approximately 21', the speed of the conveyers and the time elapsing between that at which they emerged from cooling chamber 17 until reduced to the thickness of 2 1" being sufficient to cool the mass throughout its depth to that of atmospherie temperature, whereupon the blocks are placed in a mold and subjected to hydraulic pressure toreduce their thickness to 2". It is obvious that the blocks when placed in this mold may be of any practical size but in practice I prefer that five such blocks each of the. size 18X9x2;lbe placed adjoining each other in a mold of an exact size to contain them. In the described cutting of the sheet into blocks the blades attached to the compressor rollers are at each revolution thereof dampened with water and coated with Portland cement or other dust, which thereafter prevents the sticking together of the blocks during subsequent compression together, this being primarily due to the severance of the superior bond between the particles in the various blocks at the point of cutting. Likewise the surfaces of all compressor rollers except those in

chambers

14 and 17 are, as shown by the water and dust containers 18 in Figs. 7 and 8 s0 dampened and dusted to avoid sticking, or picking up of the mass during compression and handling. Likewise the inside surfaces of the mold in the hydraulic press are so treated before the blocks are therein placed.

It is obvious that the blocks when reduced to the size 9x18x2" may be, while being so reduced from their thickness of 23;" to 2", in the hydraulic press, or afterward, further cut, by known mechanism, under hy draulic or other pressure, into blocks of smaller size. In practice I prefer to out one block 9x18x2 into eight blocks 2"x2x9 in one operation, an allowance of one inch being made for further lateral compression, and space for the knife blades intervening in this operation.

It is also obvious that the material thus produced may be, by interfering with the longitudinal positions of the particles, carted to a roadway and laid while still hot after passing through the cooler 17, as hereinbefore set forth; or the mass may be compressed into slabs of any size and thickness not exceeding 2 in the manner herein described, or the material may be cooled to atmospheric temperature upon being emitted from cooler 17, stored and then reheated at point of construction for use in being spread and rolled on a previously prepared road base in the manner in which mixtures of asphalt and sand have been heretofore laid.

I claim:

1. The process of manufacturing a composition of matter for paving purposes consisting in shearing, then shredding wood into beveled, ragged edged particles of substantially uniform thickness of not exceeding 3; and of irregular lengths and breadths graduating in descending scale of sizes from those approximately 1"xi to {'xt", IHB2LS uring and mixing 40% thereof with 50% particles,

of those in sizes graded from {WK-l, to a culoe whose diameter is the thickness of the mixed with 10% of sizes graded from that or" the largest cube to those of dimensions corresponding to the average thickness of the ragged edges of the particles; then mining particles in cacao With a preheated bitumen of ap oronimately 76* standard penetration, in quantity approximately 50% in excess of that required in the completed product; then agitating the minture while strongly heated a predetermined length or" time to partially volatilize the oil ol the bitumen to reduce such penetration o approximately to, to abnormally enlarge he particles and to separate and expel from their ennandcd ores all moisture, sap, essences, cellular tissue and pulpy matter, by destructive distillation thereof, and; by the i influence of the tan creating the vacuum, EX-

polling from the chamber containing there, all such products, together With the fumes lrom the heated bitumen, simultaneously imthe expanded pores of the pan icles, by their absorption of the melted loitumen; then draining superheated bitumen through the particles, during viloration of" their container, to settle the particles horizontally; then, when still heated to suiticient fluidity, expressing the excess bitumen from the particles, retaining in their expandpores merely enough to completely fill them ivlen subsequently contracted, to coat t m, to fill the voids between the particles en finally compressed, and to bind them LO each. other; then cooling the mass and gradually compressing the same into shape, during and after contraction of the ingredients, substantially as described.

2. The process of manufacturing composins in which graded sizes of fiat particles uniform thickness with loeveled ragged s are mixed with sulfur and then, under nlluence of heat, with an excessive quanof preheated bitumen oi oily constituency; then e osing all parts oi the mixture to the ini uence of strong heat in mono to reduce the volume of oily constitutent in the oitumen, during its absorption of the sulfur, and to reduce the situmen to a state of extreme lluidity, simultaneously enlarg ing, abnormally, the particles, and expelling therefrom, and from the chamber containing them, all moisture, essences and cellular tissue loy destructive distillation thereof, and impregnating the expanded pores with, y their absorption of, the bitumen, then drainins; the'excess of bitumen through the par ticles during vibration of their container, to set or settle the particles horizontally of the earth; then expressing a predetermined quantity of bitumen from the mass hy compression thereof, then removing the mass from the i once of heat, and partially compressir ,he satire While cooling in cacao;

nen exposing the mass to atmospheric oeratare and While further cooling,

.L 9 ng' series or reverse and transverse ro r compressions at its bottom and top suri a 5 then, when cold, rurther reducing its tniclrness by compression, and simultaneor l 1 ting same into blocks, substantially described.

3. The method of producing tion in which 'aded sizes 0:. edges are mixed to the influence of a temperature 0 matcly 500 degrees F in @656250 normally enlarge the particles and to rate all moisture, sap, pyroligneous and pulp from their expanded pores lo structive distillation of the products, taneously, by sullicient agitation, e tho bitumen to the absorbing capacity 0 expanded Woody narticles during evo of dry, superheated steam from removing, through the agency cr vacuum, the unabsorbed fumes and arising therefrom; then. cooling the m cact /o and during alter contraction the particles, compressing the same i Shane, substantially as described.

l. A method oi producing a coinnosit" of graded Woody particles mined in a chi ,1.- loer "with. bitumen While stron ly sufficient in degree to abnormally the particles ct Wood and to separate l moisture, essences, pyroligneous, and otacids and nulp therefrom; agitati mass in the chamber to the his to the ahsorhinr; capacity the Woody 1c ticles; impregnating the expanded pores c. the particles by their absorption, o servative-binder so formed, remov" the clianibercontaining it all unabsoioed steam and fumes arising from the tuen exposing the mass to atmospheric term perature, and then compressing the see c into shape during and alter contrac ion r the particles, substantially as described,

5. The method of producing a no structure of monolithic character in rad-ed sizes of flat Woody particles o5 un orm thickness, but with ragged edges a e 1 5 ixed, under the influence of heat with re-cetermined quantity of preheated loitumen, and then subjected to suficient heat to abnormally enlarge the pores of the ticles and to expel therefrom all moislare, essences and cellular tissue loy destructive distillation thereof, the particles being si multaneously impregnated by their absorption of the molten bitumen; the partially compressing the mass when spread upon previously prepared road case, during cooling and contracting of the ingredients, to substantially titty per cent, of the uncontracted, uncompr when so spread, l

im losame may at assume of the sheet being had by transverse action of the rollers thereon after the mass is thoroughly cooled, substantially as described.

6. A fibrous composition consisting of woody particles of uniform thickness and irregular lengths and breadths, impre nated and bound by bitumen in planes su stantially parallel to each other.

7. A fibrous composition consisting in graded sizes of Woody particles of uniform thickness and irregular lengths and breadths, with beveled and ragged edges,

from which particles have been removed sap, cellular tissue and moisture, impregnated with bitumen, and compressed into shape, substantially as described.

8. A fibrous composition consisting of woody particles With beveled and ragged edges, of uniform thickness, shredded into various lengths and breadths graduating in irregular area varying from 1X3;" down to dimensions corresponding with the thickness of the particles, mixed in predetermined quantities in regularly descending gradations from the largest to those approximately ,"x forty per cent; those from {k -t to dimensions corresponding with the thickness thereof, those of particles in size graduating from all of the greatest thickness to those of dimensions corresponding to the thickness of the rag ed edges of the particles, 10%, from which particles have been removed sap, cellular tissue and moisture, impregnated With a cementitious Wood preservative and compressed into shape substantially as described.

9. A fibrous composition consisting in graded Woody particles of uniform thickness and irregular lengths and breadths with beveled and ragged edges, from which particles have been removed sap, cellular tissue and moisture, coated and impregnated With a Wood preservative of cementitious nature and compressed into shape.

10. A paving block of fibrous composition consisting in graded woody particles of uniform thickness and irregular lengths and breadths, with beveled and ragged edges, from wvhich particles have been removed sap, cellular tissue and moisture, impregnated and bound with bitumen in planes substantially parallel to each other, and cut so that its breadth is that of the thickness of the compressed sheet of which it formed a part.

11. The method of producing a monolithic paving structure, consisting in chipping Wood into particles of various shapes and graded sizes; then coating the particles in a drum with preheated bitumen, through which bitumen under sustained heat and during agitation of the mass, the cellular tissue, sap and moisture in the particles are destructively distilled and then expelled from the drum, simultaneously exhausting the absorbin capacity of the particles with the heated itumen; then depositing the mass onto a previously prepared road base and compressing the same into shape.

12. A monolithic pavement structure consisting in graded Woody particles of uniform thickness, and-irregular lengths and breadths, from which have been removed sap, cellular tissue and moisture, impregnated and coated With a cementitious preservative and compressed into shape.

In testimony whereof I have atiixed my signature in the presence of tWo Witnesses, the twenty-second day of January, 1916.

GEORGE A. HENDERSON.

Witnesses L. J WVHITE, C. W. ZERKLE.

live centa esoli;by ddrcaatng the commissioner 'tls' Worthington, D. Q.