US 1702730 A
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' Feb, 19, 1929. 1,702,730 l c. E. HITE WALL PRODUCT ANDv APPARATUS FOR AND METHOD OF MAKING SAME Filed April 21, 1924 l 40 obstruction to the Patented Feb. 19, 1929. l
UNITED STATES CHARLES E. HI'PE, 0E PHILADELPHIA, PENNSYLVANIA, AssIGNoR, BY MEsivE As- SIGNMENTS, TO UNIVERSAL GYPSUM & LIME CO., OF
RATION OF DELAWARE.
CHICAGO, ILLINOIS, A CORPO- WALL PRODUCT AND APPARATUS FOR AND METHOD OFl MAKING SAME.
Application led April`2l,l 1924. Serial No. 707,966. i
This invention relates to an improved wall product and apparatus for and method of making the same. The term wall product is used generically in the appended claims as .smeaning blocks, boards, panels or slabs of various kinds for use' in the construction of walls, floors, .roofs or other purposes. The invention relates particularly to a product, and the manufacture thereof, technically known in the art` as plaster block which is a blocklaid up in mortar and largely used in the construction of partition walls.
Blaster blocks as ordinarily manufactured are approximately 12 inches wide, 36 inches 15 long and 3 or 4 inches thick.` They are usually made of a mixture of comminuted calcined gypsum and water. In order to reduce thev Furthermore, the openings in the blocks pro- -vide ready'avenues for the passage of sound which `is very objectionable.. One' of the objects of my invention is the provision of animproved wall product which will be economical to manufacture and light in weight without the use of' any woodor other @quiva-- lent filling material and preferably without having any openings extendingl through it but which, nevertheless, will be strong and durable, and provide apractical and efficient passage of heat, cold and sound. t I,l vBecause of the nature ofthe filling material heretofore used in the mixture for the blocks, the only practical wlyo manufacture them has been to cast them in individual` molds equipped with 'suitable cores. As ordmarily carried out, this method of manulfacture is slow and requires alarge amount of manual labor; hence the cost 0f manufacturing is very considerable. Some attemptisl'have been made to provide machines equipped with molds carried by an endless conveyor in `combination with mechanisml for inserting and withdrawing the cores' for continuously casting blocks. Since the blocks must be set sufficiently to hold their shape before the cores can be withdrawn therefrom and the blocks can be discharged from the molds, it will be seen thatthe conveyor must be very long if itis to travel at a fair speed and the output of the machine per day is to be very great. The initial investment ofcapital in such a macnine is 'not only large but the mechanical diiiculties of operatin it are very great. For instance, the weight o the product on the conveyor is, of course, very great and it is diiiivcult to maintain the parts forming the molds ytight so that the mixture will n'ot run out before it sets; and the mechanisms-forinserting and withdrawing the cores are complicated and it is .diliicult to maintain them in proper working order.- Another obect of my invention is to provide a wall product 'of such construction that it may be manufactured expeditiously by the use of very simple, reliably operating and relatively inexpensive machinery and with very little, if any, manual superv1s1on.
A further object of my invention is the provision of an improved method whereby the manufacture of the improved wall product aforesaidmay be carried out expeditiously and at aminimum expense. Y
Another object of my invention is the provision of apparatus of simple construction, eiiicientin opera-tion and well adapted for continuously carrying out the manufacture of l`ihe improved wall product aforesaid.
y from the following description of a preferred embodiment thereof taken in'connection with the accompanying drawing wherein is illustrated a preferred form of apparatus suitable for practicing it and in whichinvention will be better understood,
Fig. 1 is a diagrammatic view of the appa- 4 ratus; v l
Fig, 2 is a transverse sectional view, on an enlarged scale,- of the traveling moldv employed in the apparatus;
Fig. Bis a perspective view on an enlarged scale of a fragmentary port-ion of a block constrcted in accordance with my invention; an c Fig. 4 is a diagrammatic view of the'prein which the solids constitute the major pro-` portion, by Weight.
The composition facings 5 and 6 of the product may be "made by casting a plastic mixture of comminuted c'alcined gypsum and Water in the relative proportions of 60 and 4() per cent, by Weight, respectively.
The materials for the core are preferably prepared in the following manner: A quantity of a suitable amylaceousmaterial for example, corn starch, is mixed in a tank by a mixer 31 of any approved type with a quantity of cold Water introduced through a pipe 32 and valve 33 and thoroughly stirred until the starch is dissolved and the starch grankettle 34 provided with suitable agitatingl ules are separated one from anothery thus providing a starchy liquor. The starchy liquor is then placed in a suitable steam jacketed means 35, and suiicient cold Water is placed lin the kettle to bring the Water content of the liquor up to approximately 18 or 20 *timesas much, by Weight, as that of the l starch, the Water ing introduced through the pipe 32 and a valve 36. The transfer to the kettle 34 is preferably effected by means of, apipe 37 and pump 38.l The yagitating means in the kettle is then set in motion and heat is applied to bring gradually thetemperature of the dilutedPV liquor up to 190 F.
The individual starch granules are burst and thoroughly mixed with the Water whereby the starch and water are converted into a viscous agent of 'smooth uniform, texture. lThe application of heat is thendiscontinued and sufficient cold Water is introduced to bring the Water content of the viscous agent up to substantially 31 times as much, by
weight, as that of the starch material and' at the same time to reduce the viscous agent tothe desired temperature. The additional WaterI may be added in the kettle 34 or' the addition of suchwater'may be effected in a second mixing tank 39 to which the liquor has been transferred thlollghjthe. medium of a pipe 40 and pump 41.1) l'f desired, some suitable acid may be added,-for example, one
part 'of sulphuric acid for two hundred parts y v veight of the 1iquor,-the 'acid .being introduced througha pipe 42. The added Water or Water and acid are thoroughly mixed with the liquor by means of the agitating means 35 or by means of an agitator' 43 in the A tank 39. The diluted cooked paste may then be drawn from the kettle 34 or the tank 39 and thoroughly mixed With comminuted calcined gypsum in the proportion of approximately fifty pounds of the paste to forty `pounds of the gypsum, the paste having meanwhile beenv transferred by a, pump 44 through a pipe 45 to an elevated storage tank 4G substantially in accordance with my co` pending application Serial No. 707,965, filed April 21. 1924. A
The apparat-us preferably used for continuously manufacturing the product includes a mixer 7 in which the materials for the bottom facingare prepared, uater being supplied from a pipe 8 and commiuuted ealcincd gypsum from a source of supply 9 by a drag chain 10. The materials are thoroughly mixed in the mixer by continuously operating propeller blades 11. The materials for the core are prepared in a mixer 12 to which the amylaceous paste or the acidulated amylaeeous paste is supplied from a .pipe 13, the commin'uted gypsum being supplied from a source of supply 14 by means of a drag chain 15. The paste and gypsum supplied to the mixer 12 are thoroughly mixed by the\con tinuously operating beater blades 16. The materials for'the top facing of the product are prepared in a mixer 17 supplied; with' water from a pipe18 and With'calcined gypsum from a source of supply 19 by means of a drag chain 20, the-' water and( gypsum being thoroughly mixed' by continuously operating beater blades 241. An endless mold 22 travels, in the direction indicated by the arrow A. over rollers 23 and 24. The mold of the form shown in cross-section in Fig. 2 and comprising a bottomportion 22 and vertical side portions 22b may be used. The mold may be formed of a fabric foundation material suiiiciently yieldable to permit the mold to travel around its supporting rollers. The material for the mold is preferably impregnated or covered with rubber, or otherwise treated, so that the interstices of the fundation material will be filled and the interior of the mold Will be smooth. lThe upper run of the mold may be supported in any desired manner, for example, by an under frame or table 25.
The plastic mixture for the bottom facing il is continuously delivered from the mixer 7 through a discharge spout 7a into the mold, the mixture being spread substantially uniformly in the bottom of the mold by a roller 26v which operates in thedirection indicated by thearrow B.. The plastic mixture for the core is continuously deposited from the mixer 12 through a dischargespout 12il onto the top surface of the bottom facing, the mixture for the core being spreadunformly in the mold on said facing by a roller 27 which operates in the direction indicated by the are? row C. The plastic mixture for the top faci- 13o 'ing is continuously supplied from the mixer 17 through its discharge spout 17 onto the top surface of the core, the mixture for said" deposited onto the-facing. Some of the mixture for the core, however, does work into the interstices of the facing which is desirable' as it insuresagood mechanical interlocking of the core and 'the facing. 4Likewise the distance between the mixers 12 and 17, with respectto the speed'of the mold,'is such that the core hardens sufficiently to support the mixture for the top facing, when the latteris depositedbntov the'core, and here also there is sufficient intermingling of the mixture for i the facing with that of the core to insure a v good mechanical 'bond between the facing and the core. By the use of acid'as above specified, the time required for the setting of the core is very materially cut down, the acid being adapted t-o react'with'carbon'ates in the vmixture to form nascent salts for effecting this result. -If the gypsum is deficient in carbonates contained therein as impurities, such carbonates may be added as requlred. Since the mold is of considerable, length and travels quite slowly, the cast laminated sheet-. like product, by the time it reaches the delivery end of the mold, has set sufficiently to be self-su porting and therefore it ma be cut into b ocks of the desired size and either placed in a drying kiln to eliminate the moisture in excess of the water of crystallization or stored in a shed or .a yard so that the excess moisture may evaporate. When plaster,bloeks are manufactured the mold may be made 3 or 4 inchesi deep and 36 inches wide and the product may be cut off in lengths of 12 inches.
The f'acin'gsft on the blocks will ordinarily be from to1/2 inch in thickness. The mixture for each facing sets into a ysheet-like mass which is very hard4 and very dense. When the amylaceous material and the water for the paste used in preparing the mixture 'for the core are combined in the manner herein described,'theresultant viscous agent is free of lumps and is of a smooth, uniform consistency. The articles of gypsum are thoroughly and uni ormly distributedthroughout the agent and are held insusdpension while crystallization takes place. Because of the uniform distribution ofthe gypsum particles throughout the paste, the
core of the productis very porous and, tllere- Y fore, light in weight.
A block manufacturedaccording to my invention is superior to the old style wood vfilled, cored bl'ock of the prior art for the following reasons; (a) The dense hard facings on the opposite sides of the porous core of /uniform cellulaiconstruction provide a very strong structure capable of withstanding severe shocks and jolts without cracking or breaking. Shocks imparted to one facing are not transmittedtothe other facing because of the shock absorptive capacity of the cellular core; consequently, the' likelihood of breakage is reduced vto a minimum. (b) Since. the improved block is not cored, there are no avenues running through itfor the passage of heat, cold, fire or sound. (c)
Since lightnessof Iweight is obtained by aJ cellular-structure without the vuse of a wood filling material, the improved block is more fire-resisting. (d) The uniform cellular construction of the core with the innumerable dead air cells affords aAv practical and eiiicient.
obstruction tof the passage of heat, cold or sound. (e) The construction of. the improved bloek is such that it may be economi- 'cally and expeditiously manufactured by 4thc continuous mold method, requiring very simple and inexpensive machinery and Very litt-le, if any, manual supervision, thus doing away entirely with the individual molds, the expensive, complicated and unreliably operating mechanism for maintaining the Amold parts tight and for inse-rtingand withdrawing the cores fromy the respective molds, and all the' delays and expense incident to the operation of such machinery; hence the cost of manufacture of the improved productV is very much ,less than that 1of the old style blocks.
The relative quantities of the materials vused in the core as herein se't forth-are the best known to me for accomplishino the desired results, but I do not intend to Llimit my invention to the relative quantities specified. as variations may be made, depending somewhat on the qualities o f the materials and the strength and weight of th'product desired, without departing from the principles ,l of my' invention.
-I do not intend to limit my invention to the details of construction and the -detail steps of manufacture shown and described, except only in s o far as certain of the appendedclaims are specifically so. limited, as it will be obvious to those skilled in the art that various modifications and changes there- I .in may be made withoutl departing from the.
principles of my invention.
While I have described herein specificallythe manufacture of plaster blocks of a cer.
i cined vadapted by reaction with the acid to produce .a plastic mass obtained by mixing acid, coniininuted call-ined gypsum containing an im# purity adapted by i'eaction with the acid to vhasten the settinsr of the 0 sum, and a h sa h.
dro-iiuylaceons paste capable of sustaining` the particles of gypsum in suspension during setting, and then causing the product to be dried.
2. The method of making a wall .product which consists in casting a facing consistingl of comininuted calcined gypsum and Water, casting in conjunction with said facing a plastic mass obtained by mixing' coniminutcd calcined gypsum, sulphuric acid and a-hydroamylaccous paste capable of sustaining the particles of gypsum in suspension during setting, and then causing the product to be dried.
3. The method of continuously making a wall product which consists in casting and advancing acomposition facing, preparing a mixture of sulphuric acid, comminuted calgypsum containing an impurity a salt and a hydro-'amylaceous paste capable of sustaining the particles of gypsum in sus# pension during setting, casting a body of said mixture onto said facing, severing 'the result- I ing product into the desired lengths, and then causing' it to be dried;
4. A unitaliylaliiinated wall product com prising in combination two dense hard cour position faeings, and an intermediate core of cellular texture secured to and protected by said facings and comprising the set product Aof a mixture including calcined vgypsum as the major ingredient, acid.l carbonate reacting with the acid to 'forni a nascent salt in the mixture serving to accelerate the set-ting of the gypsuim and a hydro-ainylaceoiis paste adapted to sustain the particles of gypsum in suspension during lthe setting of the mixture. I
5. A unitary laminated Wall product comprising in combination two' dense hard facings formed of calcined gypsum and water, and an intermediate coie of cellular texture' secured toboth of said facings by direct ,bonding therewith and comprising the set product of a mixture including calcined gyp sum as the major ingredient, acid, carbonate reacting with the acid to form a nascent salt in the mixture serving to accelerate the setting of the gypsum, and a hydro-amylaceous paste adapted to sustain the particles of gypsum in suspension during .the setting of the mixture. i CHARLES E. HITE.