US1219388A - Art of impregnating timber and other material with a preservative. - Google Patents

Description

UNITE sra'r s OLIVER P. M GOSS, OF SEATTLE, WASHINGTGN.

ART OF IMPREGNATING TIMBER AND OTHER MATERIAL WITH A PBESERVATIVE.

No Drawing.

To all whom it. may concern:

Be it known. that I, ()Iavnn I. M. (loss, av citizen of the United States, and a resident of Seattle, county of King, State of Washington, have invented a certain new and useful Improvement in the Art of Imprege nating Timber and other Material \Vith a Preservative, of which the following isv a specification.

My present invention is particularly concerned with the treatment of timber, such as railroad ties, paving blocks, woodstave pipes, special kinds of lumber, and the like, and it has for its special object the producing'of ties which conform with the demands of the market at the present time, that is, ties which have been efiieiently, but not wastefully, impregnated with the preserving material, 'and furthermore are thoroughly surface dry.

In order to f lly attain my object I preferably pursue the following method: I place the timber to be, treated in a retort made with a door adapted to be hermetically sealed. Then I introduce a preservative such as coal tar, creosote, or other b-ituminous liquids into the retort, after which 1 heat the preservative to a temperature of approximately 230 degrees Fahrenheit under normal pressure; then I draw a vacuum of from 15 to 28 inches-in the retort; then, without disturbing such vacuum in the retort, I maintain the. 'heat of the latter at a temperature above that of boiling water under such vacuum, for not less than one-half hour. Then I break the vacuum -the retort, and then. apply pressure on thefluid in the retort suflicient to force into the ores of each cubic foot of the material eing treated approximately from 5 to 20 pounds of the fluid. r

In order to render the surface of the treated material dry, the following additional steps must be taken. Reheat the fluid in the retort from 1 to 6 hours additional to the temperature of from 200 to 240 degrees I ahrenheit, then empty the retort of the preserving fluid; and, finally, while the material is still in the retort, and hot, draw the vacuum in the latter offrom 15 to 28 inches. By this process the surplus preservative will be drawn out ofthe poresot the material and the latter thus renders the surface dry. The reheating ot the preservative will cause the gasesin the pores to J expand and thus facilitate the rejection of Specification of Letters Patent.

Application filed October 11, 1915. Serial No. 55,2i77.

the surplus preservative when the final vacuum is drawn. i i hen the material is finally taken from then-tort and cooled, the contraction of the gases in the pores will tend to draw the remaining preservative well into the 'pores and thus leave the surface of the material dry. I l

The above described process will not he su-fi'icient to insure the thorough penetration of the preser'ative into the pores of some material. -In this case the following procedure should be substituted for the steps outlined in theforegoing paragraph. Reheat the fluid insthe retort for from 1 to 6 hours, continuously, to a temperature oi from 15. to 28 inches on the preserving fluid in the retort, then, while still under suco vacuum, continue the heat above the boiling point of water under the vacuum for not less than one-half hour, then break said 1 vacuum and empty the retort of the preserving fluid; and, finally, while the material is still in the retort, and hot, draw a vacuum in the latter of from 15 to 28 inches up roximately.

I n describing my process I have necessarily to avail myself of a wide range in the degree of heat, in the vacuum produced, and in the length or time during which a specifio treatment is carried on, for it is impossible to be more specific in these details,

since different materials have difi'erent na tures and require corresponding variation of their treatment. These specific details must, in the first instance, be determined for the different materials by a preliminary trial.

In short, the variations of my process are for the purpose or limiting the Work done on the material to that required, in order to attain the best results, in which the following is essential: First, the thorough expulsion of moisture from the timber, second.

the foreingof sufii'cient preservative ivcll into the pores of the material, and lastly. the e]ect10n of surplus preservative so that the surface' of the treated material will he dry, which conditions are generally demanded by the market.

pressure, then drawing a vacu'um'e'l' a p proximately 15 to 28 inches in the container and maintaining the heat of the latter at a temperature above that of boiling water under said vacuum for not less tli nhalf an hour,

then breaking such vacuum, and applying" under said 'vacumn, for not less thanhalt an hour, then breaking such vacuum, and applying pressure sulllclent to force approximately from 5 to Zn pounds of the preservative fluid into the pores of each. cubicfoot of material, then reheating the fluid .in th e container for from. one to six hours continuously to a temperature of from 200 td2l0 degrees .ll ahrenheit under normal pressure, then emptying the container of the preserving fiu1d,.and

QinatelyQ then, while the material is v f still hot, drawing a vacuum in the container of from 15 to 2b inches approxnnately.

3. In the preserving treatment of porousmaterial, the method which consists in first heating the; material in a 'hitulnlllolls' preservative", in a? closed container, to approximately 230 degrees Fahrenheit under 1101' mat pressure, then drawing a vacuum of approximately 15 to 28 inches on the preserving lluid and continuing to heat the latter to a temperature above that of boiling water under said vaclnlnntm' not less than halt an hour, then breaking such vacuum, "and applying pressure sutliciehtly to force approximately from 5 to 2() pounds of the pr-eservat'ire fluid' 'into the pores of each cuhic teot of material, then reheating; the

fluid in the centainerfor fI'OIIY'OIlG to six hours continuously to 'a temperature of from 200 to 2&0 degrees Fahrenheit under normal pressure, thenilrawingga vactjuini of 15 to 28 inches on 'preservingfluid and boiling in the fluid under; this yacuu'm for not less than one hour, tlienj breaking such acuum and en jtj ingtlie cOntainer of the ,preserving' flu d, and=t"hen,While the material is still' hot, drawing' a vacuum in the