US1556703A - Process of fibrating asphalt - Google Patents

Description

Patented ca. .13, 525.

UNITED STATES ALAN" R. LUKENS,

PATENT OFFICE.-

PROCTISS FIIBRATING ASPHALT.

No Drawing.

To all whom it may concern.

' Be it known that I, ALAN R. Lumiere, a citizen of the United States, and a resident .of Wyoming, in the county of Hamilton and State of Ohio, have invented a certain new and useful Process for Fibrating Asphalt,

of which the following is a full, clear, and

- exact description.

My invention relates to improvements over the process developed by James C. Woodley, of incorporating fibers as set forth inhis patents, among others United States Patent, No, 1,156,122, dated October 12,

-- 1915. I It also relates to an improved prod- 15" not resulting from the process. I

I In the processes of Woodley, molten asphalt, vegetable fibers, in a wet st-ate, and mineral ler, lar to a' bakers dough mixer, until a plastic or semi-granular state is. reached in which the asphalt has so changed that upon ignitionof the material, no asphalt will-melt out,

' and in which the fibers are in complete suspension in the asphalt. As described by microscope the fibers of a piece of the \Voodley material are in individual condition, but are chop edup into pieces. These pieces'are with difficulty visible to the naked eye, although they act to strengthen and toughen the asphalt very considerably, but they do not impart near as much strength as if they were of greater length.

I find that by proceedin in a different way I can still gindivi'dua'ize the fibers,

thoroughly coat each fiber with asphalt or itumens of similar nature, and imother cor crate into the mix a large quantity of fine y divided mineral matter, such as a dia--' tomaceous earth, without breaking up the individual fibers into parts.

Of course, if a mineral matter of nonare kneaded in a mixer simi-.

Application flied January 4, 1928. Serial R0. 610,704.

abrasive nature substantially small in quantitles be used in the Woodley process,

'the reduction of the fibers will not be so great. The real problem comes when it is necessary, because of the uses to which the,

final material isto be put, to use a substance which has an abrasive quality very strongly marked, or where the mineral maton wromm onro, .assrenon To run nronennson comm, or nooxnnnn, 01110, A conrom'rrou or 01110.

ter must be present in a predominating v quantity. I use in my process, by preference, a diatomaceous earth.

In processes which mvolve the steps of first dispersing bitumen in a watery aste of colloidal clay, and then mixing 1t with fibers, and finally drawing out the'water from the clay, and thus reviving the bitumen, the limlts as to bituminous content ofthe final product are quite distinct. Such processes, as used in resin sizing, or asphalt SlZl-llg of paper are termed emulsification processes, and not only are much more limit;

ed as to result than my rocess, but in the nature of the action invo ved, are about the converse of my process.

Furthermore a clay finely divided enough to act as an emulsifying agentis usually not.

of a character suitable for acid resistance products, so that in range of minerals which may be used, my processis distinct over a fiber sizing process.

Known emulsification processes, while the may be carried on within certain limits, an not be similar to the Woodley product, ed 1 have very definite limitations in the amount of bitumen whichcan be incorporated .into the product. In fact, in commercial uses of the mulsification process, the usual practice results in a great excess of fibers over bitumen. My rocess gains the advantages in length of fi er of the emulsifying p ocesses, and still has a body high in bitumen and.

result in a product which may orma 7 hard because of the presence of mineral matter, and may have other superior qua-ltities due to a chance for selection of special -minerals for special uses.

Thus, myv process and product have advantages not obtainable in any other manner, 'Ihe apparatus used with my process consists of mixers, similar to those used by bakers for mixing large batches of bread the presence of water.

dough, and sufiicient heating devices to maintain asphaltin a molten condition in The essential feature of my invention is that I mix, a bitumen such as asphalt and mineral or earthy matter in-one beater, and the same or a similar bitumen together with fiber in another, and then mix the two resultant bodies together. I find that by properly mixing finely divided mineral or earthy matter and asphalt without emulsification, I obtain a form of suspension in which each particle of finely divided filler is surrounded by a film of asphalt and is thus greatly deprivedof its abrasive qualities. Then when both the fiber and filler have been previously coated with bitumen they readily and quickly blend together in a homogeneous mass without such final kneading or mixing, seriously pulverizing, or shortening the fiber. I'thus obtain a mass which is stifi and strong yet is not brittle nor fragile.

Proceeding to described a typical commercial use of my invention, I first determme what proportions sa of an asphalt, and mineral matter and her, which I desire in my final product. I then place in the first mixer the least amount of the asphalt which will properly fully coat and disperse the fiber, which action I have termed fibration,

and in another mixer I place the balance of the asphalt to be used for the purpose of thoroughly coating the mineral or earthy matter.

While then maintaining heat under each mixer, into the firstmixer I place the desired amounts of fibers which may be in the form of scrap paper in a well moistened condition. As this mixer operates, it first disperses the fiber throughout the mass of asphalt and thereafter evaporates all of the water. Into the second mixer I place the desired quantity of mineral or earthy matter, and operate it to knead up the product. Into the mineral or earthy matter mixer 1 add sufficient water, well short what would be an emulsifying quantity, yet suflicient to break down surface tensions topermit the mineral or earthy filler to enter quickly into full suspension.

As soon as the filler hasbeen uniformly dispersed I permit the water to evaporate as steam, addin no more water. After the water has thus eft the mixer and thetezhperature has raised within the mixer sufficiently to convert the mix into a smooth plastic mass, the action of the mixer is stopped and the contents of the fibrating mixer added. I A

The fibrating mi-xerha's been operated. all of this time, and, as taught by W'oodley, the

action of the tackyasphalt on-th'e wet paper or fibers will be to; tear the fibers' \up into. their original condition, and tolbre'ak-down surface tensions at the same time suificiently that the fibers enter into suspension in the asphalt, the Water not evaporating until this weaves materially difi'erent from the Woodley roc- 1 ess, while the fibers are not materially ortened in length having been mixed only for a short time in the presenceof the mineral or earthy filler, and the filler beingat the time well coated, or --lubricated with the bitumen used.

As a material for the production of 'elec-" 'trolytic jars, which is readily moldable, and has air suspension, sufficient to permit considerable compression in a die, the .material produced by my process is very superior. 'It can be made bothhard and tough, the fibers are thoroughly distributed, as is themineral matter, and the length of the fibers seems to increase their strength in holding themass I together without in any we afl'ectin the colloidal nature of the fina materi It may not be precise to designate as colloidal, the nature of thematerial wherein it differs over an asphalt which has boon-filledwith other materials, such as fiber andimineral matter, but in which the nature of'the asphalt has not undergone a change. This change, as has been stated, is quite evident from the point of yiew'offusib lity, my material being fully as infusible as. that of Woodleya By referring ,to asphalt diatomaceous earth and paper fiber, I" do not 1 wish tolimit my claims that follow beyond" the usual range of e uivalents of such'materials, nor do I wi to limit-my process. to a simultaneous action ,of two mixers or any special instant for combining the two 7 mixes or the particular manner of combining them or to the necessity of immediately making the final mixes before the first mixes become cold.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is: v 1. A process oi hardening and toughenin asphalt or the like bituminous bod whi'cfi consists in mixing "a bitumen anddivided matter having abrasive qualities,=' "1nde-' endently thereof, mixing a bitumen-and fibrous material, and final y placing the twomixed masses together and them, whereby the abrasive qualityofthe matter against the fibrous material is reduced in said final mixing.

2. A process of hardening and toughening asphalt or the like bituminous body, which consists in forming two mixes, by kneading together a bitumen and finely divided matter having abrasive qualities and independently kneading together bitumen and fibrous material in the presence of water and heat, and then evaporating the water and finally mixing the two masses together produced by the in ependent kneading.

3. A process of hardening and toughening asphalt or the like bituminous body, which consists in forming two-mixes by kneading together a bitumen and finely divided abrasive matter, and independently kneading together bitumen and fibrous material in the presence of heat and an agent to first form a film about the fibrous material which film is then replaced by the bitumen, and finally kneading together the mixtures so prepared ALAN R. LUKENS.