USRE17523E - op chicago - Google Patents

Description

Reiteued Dec. 17, 1929 UNITED STATES PATENT oFFicE a RICHARD EBICSON, OF CHICAGO ILLINOIS ASSIGNOB' '10 UNITED STATES GYPSUI 00., OF CHICAGO, ILLINOIS, A CORPORATION OI ILLINOIS LIGHT-WEIGHT CERAMIC MATERIAL AND PROCESS or name THE am 1'0 Drawing. Original No. 1,702,078, dated February 12, 1929, Serial 10. 828,259, fled 14, 1027.

Application for reissue filed October 11, 1929. Serialv No. 899,088.

1 This invention. relates to a porousand light weight cellular ceramic product, and a method for producing and manufacturing the same commercially. I p

Q The use of foam or other density reducsubstance in connection with cemetitious materials to form porous cellular compositions when set and hardened to finalstate with water, is becoming established as one commercial means of producing a light weight material. I am not aware that anything of this principle has been applied to the production of ceramic materials where an argillaceous, earthy material is given a I porous structure by admixture with a tenacious foam reducing agent and subsequently this porous argillace'ous material is heat-- treated to render its cellular structure fixed in a finished ceramic product.

A comparatively light porous material suitable for structural purposes or suitable as a heat insulator can be made from clay or other argillaceous earthy material, by first forming a plastic mixture of the earthy material with water, then mixing in a previously prepared tenacious foam or other density 1 to uniform admixture, next forming the mass ilito a cast or'shaped product of any desired form, then drying this cast to preserve its cell structure, and finally baking or burning this dried cast until a hardened mass results which retains permanently fixed the porous desired fineness state through suitable disin-" tegration or grinding means and rendered. lastic with water. However, in my process reduce to perhaps a more fluid plastic state than is the ordinary practice in the production of common ceramic products like brick w or tile- This is usually necessary-because the addition of foam to provide the porous structure has bulking effect, and additional fluid- I lty, 1n the plastic earthy material, is needed 1 to take care of this and to fully preserve the 'foam from breaking down somewhat as it does 1f the plastic mixture itself is too stiff.

The material for forming the foam may conproducing tenacious foam from a water solution such as soap bark, licorice, commercial plaster retarder, glue, soap, resin soap, and various admixtures of these, etc. The foam itself maybe made by beating the water solution violently or by introducing a cursist of any number of materials capable of that it can be'readily mixed with water. Sufficient water is then mixed with it to form a plastic mass of such consistency or fluidity that foam can readily be mixed thereto. With certain shales I have used, this is about six tenths of one part of water by weight to one part of ground shale. used is made by dispersing air into a solution composed of three quartersv of one part of powdered soap bark suspended in one hundred parts of water, and this foam if properly prepared is very stable and preserves its structure for a long time. The

quantity of foam used is about five parts ofv The foam i foam by volume to one part by volume of the shale and water mixture, and will give a resultant ceramic product having a density of about thirty pounds per cubic foot. The mixture of shale, water and foam is then dried and after drying it is baked or burned at about the temperature and method used in burning the ordinary brick or tile products made from the same shale, care being takenffnot to fuse or melt the product during the:iburn ing or firing stage. Afterrthe burning, the, .7 hard porous product is ready for use in a, variety of ways. If the original shape of the cast was a brick, this finished porous brick is then available for an insulatmg backing- "other densi' reducing or less stability than the soap bark foam cited, plastic mixture of argillaceous substance,

of invention. Other up brick in-hi htem rature insulation work. Or-the burnegl pro uct can be crushed and sized into an aggre to for use with a cementing material to g ve a moulded and cast structure prepared as desired on the job. .One use of this crushed product is as a light weight aggregate in the'production of Portland cement concrete.

I have noticed in some cases. where extremel light weight products (25-30 pounds r cu ic foot density) are desired that these 0am clay casts when dried exhibit some cracking and shrinking. This of course, de pends somewhat on the nature of the clay or'shale used as a. base, and is what is ordinarily experienced in the generalmanufacture of ceramic products. But in my light weightfoam process, the natural tendency of the clay or shale in this direction of course, is an ented, because after the foam addition e composite mix is less dense and consequently somewhat fragile. Thus, there is greater opportunity for shrinking and crackmg during drying to manifest itself. If the fimshed ceramic products are to be used as crushed egates this. of courseis immaterial, but if the finished porous light wei ht ceramic product is to be used intact itself or structural purposes and thus mustretain the fonn and size which it was cast, some additions mu bemade to the. clay or shale just as in ordinary ceramic practice to offset this shrinkage and cracking. The addition of silica, flint, grog, and other coarser body.

and

materials is usefu in this ca acit have also found a mixture of ca cine gypsum or (plaster of Paris setsrapidl with water an thus hardens the cellular c ay mass sufficientl to withstand the shrinking effect induced y the later drying. The calcined 14- v: I u mixed with "water can be added to e mixture of argillaceous material and foam with d results. Accelerating the set by the cined gypsum decreases the time required before the subsequent mixture stiffens. However when gypsum" is used, more care must be taken in burning the dried pdrous product because usually the fusing or melting point ofsuch mixture is lowered by the addition.

Many modifications of this invention will 4; w themselves'and'I do not .wish to be limited in various applications of thisprinciple, for the various modifications that suggest themselves do not depart from the spirit types of argillajceous material other than the natural earth materials used may suggest themselves su I I as built-up artificial refractory raw mate-1 rials made plastic b only smalladditions of clays or shales; an many types'of foam or agents with greaterma be used. Also other methods of drying an burning may used than merely presame. For exam la, the casts may tially dried and t en placed in a rotary iln where they can be further dried and burned the burned product resultin paring unit casts drying and burning the in one operation if the material is. intended for use primarily as an a gregate.-

Having thus describe my invention, what I claimis:

1. A porous ceramic material comprising the burned product resultin from heat treating amixture of foam an argillaceous material.

2. A porous light weight ceramic product com rising burned argillaceous material ma e porous byfoam addition while plastic. 3. A 1i ht weight structural material comprising t e burned product resulting from heat treating argillaceous material in which a tenacious foam is incorporated prior to dryinlgv and burnin stance, tenacious foam, and substances crac in during dryin 5. A g

prising t e .burned product resulting from heat treating a mixture of argillaceous material, foam, calcined gypsum, and water. 6. A porous ceramic material comprising treating a mixture of one part y volume'of a plastic mixture of argillaceous material and water, with five parts of tenacious foam. 7. A' cellular ceramic product comprising the burned product resultin from heat treating a mixture of one-part y volume of a plastic mix of argillaceous material and water, four parts of tenacious foam, and one third art of calcined a 8.* T e process of manu acturing a porous product com rising forming afluid plastic mixture of terial with water, incorporatm therein a tenacious foam, shaping and drying this'admixture and finally heat treating. a dried porous mass tomaintain a substantial hardened cellular product.

9. Theprocess of manufacturing a porous ceramic material comprising the incorporation of tenacious foam into a fluid plastic mixture of argillaceous substance and water, thefoam volume being in excess of the volume ofargillaceous water mixture used, caste ing this resultant mixture into desired shape, drying, and finally burning the dried porous mass at a temperature below its fusion point foam and water, calcined gypsum to prevent shrinkage durin'gsubsequent loss,

porous ligfitrweight material com-' "prlsing the-burned product resulting from eat treating a mixture of argillaceous sub-.

Eht weight ceramic material comfrom heat nely divided ar 'llaoeous ma- Y drying I this composite mas, and finally heat treating the dried porous mass at a temperature below its fusion point to yield a hard- I ened porous product.

urmng. o -12. A rous light weight material com burn Erising t e product resulting fromeat treating a mixture ofargillaceous substance, a density reducing substances adapted to prevent excessivev shrink 15 ing andcracking during drying.

13. A light weight ceramic material our. rising the burned product resultingirom t treating a mat ure of argillacecus material, a density reducing agent and calcined 14. The proces of manufacturing a porous product comprising forming a fluid plastic mixture of finely divided argillaceous matenal' vith water, incoslflporating 1313mm a (lain; ym u g h w y admixture, and finally heat treating the a! v porous mass to maintain a substantially h ened, cellular "product.

15. The proces of manufacturin aporous l0 ceramic product, comprising ad g to a plastic mixture of-argillaceous substance, a

density reducing agent and water and calcined gypsum to prevent shrinkage during subsequent moisture 10s, drying this com- 85 he mixture, and finally heat treating the porous mass at a. tem" ture-below itsfusion point to yielda ardened, porous ERICSON.