US921000A - Manufacture of water, acid, and alkali proof articles. - Google Patents

Description

I. L. ROBERTS. MANUFACTURE OF WATER, AUID,'AND ALKALI PROOF ARTIOLES;

APPLIOATION FILED 001.3, 1907. 921,000, Patented May 11, 1909.

- Way the .UNITED sTATEs PATENT OFFICE.

ISAIAH L. ROBERTS, OF LOCKPORT, NEW YORK.

MANUFACTURE OF WATER, ACID, AND ALKALI PROOF ARTICLES.

Specification of Letters Patent.

Patented May 1 1, 1909.

Application filed October 8, 1907. Serial No. 395,663.

To (I'll whom it may concern:

lzle it known that l. Isauu L. Ronnnrs, a citizen of the l nitcd States, and resident of Lockport. in the county of Niagara and State of New York, have." invented certain new and useful improvements in Manufacture of Water. Acidiand Alkali Proof Ar ticles. of which the following is a specification.-

My invention relates to wood-pulp, strawboard or other woody material, to'be used with acids or alkalles or both, and has for its object to provide an etfective process for rendering such articles liquid proof and also resistant to the attacks of acids and alkalies.

, l-leretofore numerous attempts have been made to utilize wood, woodpulp. etc, for a rticles to be used with acids and alkalies, for example as containing receptacles or vessels for the same. A common method for the purpose is to coat the surface of the article. or to impregnate the article as deeply as possible, with acid and alkali resisting niaterial: but it has been found that after an "article so treated has been in use for a more or less short time the chemical,

especially if it be an acid, attacks the ends of the fibers at the contact surface, and fol-' lowing these fibers soon permeates the article and greath impairs it or rendersit entirely useless.

My present invention also involves impregnation of the article as deeply as pos sible. but in a novel manner, whereby a marked alteration of the character of the woody material is effected, 'Withthe result that the finished article is practically unatl'ackable by acids and alkalies.

In carrying out my invention in a simple article to be treated is immersed in a bath of resistant material, such as resin, stearic acid, sulfur, linseed oil, paraflin, etc, the temperature ofwhich is igh enough to partially carbonizethe "article, The partial carbonization, which is not carried far enough to materially impair the strength of the article, renders the material thereof porous. into the pores and interstices of which -the resistant substance of the bath enters. on removing and cooling the article the terial solidifies in the pores, leaving the article liquid-proof and thoroughly resistant. If the article to be treated is bulky or thick, the bath is preferably at low temarticles of wood,-

tures of two or more of these. permeating or nnpregnatlng' 1113- perature when the article is placed therein, after which the temperature is raised until the carbonization has proceeded as far as desired. The temperature is then reduced toa point. slightly above the melting point of'the bath, after which the article 1s removed and allowed to drip and 0001. In this way there is little if any absorption of the bath liquid until the water and gases liberated during the carbonization are all evolved, since the evolution thereof goes on while the temperature is rising, and so prevents the liquid from entering the pores. lmt when the temperature falls the evolution ceases and the liquid inunediately enters, and penetrates to a greater depth than would be the case ifthe temperature remained high.

If desired the treatment may take place in a partial vacuum, thus making the process more rapid. in a vacuum the gases are evolved more. rapidly, and on restoration of atmospheric pressure the bath liquid is forced into the pores deeply and quickly. lfiurthermore, the temperature need not be so high in a vacuum. since in a vacuum decomposition, that is, carbonization, takes place at a lower temperature.

A convenient apparatus for practicing the invention is illustrated in the annexed drawing. which shows the same in vertical section.

The furnace is of brick, inclosed in an iron sheathing lt. In the furnace is an iron vessel (1. of suitable size. to which are connected a valved exhaust pipe I). for connection with an airpulnp, and a valved inlet pipe E by which air may be admitted at the proper time. The vessel is heated by suitable ,qas burners F.

In the vessel is the carbonizing and inipregnating bath. indicated by G. As previously stated. various substances can be used for the purpose: but the substance or substances used should be capable of withstanding the necessary carboi'iizing temperature withoutdecomposition or prohibitory volatilization. Among such may be mentioned stearic acid. the resins. paraffin wax, sulfur, linseed oil, and asphaltum. and mix- Asphaltum. for instance is "too thick or viscous when heated to enter the pores of the article readily, but paraflin or resin may be mixed with the asphaltum 1n su'tlicient quantity to give the desired fluidity. The article will be waterproof if any of the substances mentioned be used, and also acid and alkali prooi if sulfur or paraflin be used. If stearic acid or resinyor a mixture of asphaltum and resin, be employed, the article will be acid proof but not alkali-proof, since the substances mentioned saponiiy in alkali. The articles, which are of course lighter than the bath even when thoroughly impregnated, are kept submerged by a suitable weight, such as perforated iron plate H. l-lollow articles, such as the pails 1, tubes J, cup K, etc., as shown, should be placed on their sides, so'as to promote free circulation 1 'or'plates, as L, may be placed below.

of the bath into and out of them. Sheets An air-tight cover, M, is now placed on the vessel (l, and the air exhausted through pipe D. As the articlues become heated the evolution of air and'gases from the articles takes place rapidly.. When the articles are suiticiently carbonized the vacuum is relieved by opening the inlet pipe and closing the exhaust pipe, whereupon the absorption of the bath liquid by the pores and interstices of the articles is completed, the increased pressure causing the liquid to permeate the articles thoroughly, as will be readily understood. The articles are then removed, and allowed to drip and cool. In the case of bulky or thick-walled articles the exhaustion of the gases above the bath may be repeated several times, or the air-pump kept at work during the treatment, to insure complete permeation. Likewise the tempera-ture' nay be low, say but slightly above the melting point-of the. bath, at the start,

then raised to the carbonizing temperature,-

and then lowered, asprevimisly mentioned.

The temperature required for the carbonization. and the length of time the articles should be treated in vacuo and under atmospheric pressure will depend in general upon the size of the articles and the material coinposing the same, and for particular ma- -terials and conditions can bestbe determined by trial. Tests can easily be made wlth desired materials and the. conditions necessary for the proper degree of carboniza tion and permeation can be readily found.

Articles treated as above described are completely liquid-proof and are practically unattaclmble by acids and alkalies. At the same time the treatment is inexpensive, .quick, and not difiicult to practice, requiring only reasonable carev and-attention on the part of the operator. -What I claim is:

l.' The herein described method of treat- ,ing articles composed of. woody material to l i Witnesses:

o21,ooo

render the same water, acid, and alkaliproof, which consists in partially carbonizing the article in a heated bath of water-' proofing ,and resistant material and permitting the material of the bath to permeate the article.

2.. The herein described method of treatmg articles composed of woody material to render the same water, acid, and alkaliproof, which consists in immersing the article in a bath of res1stant material, heating the'bath till the articletherein is parproof, which consists in immersing the' article in a bath of water-proof and resistant material, producing a partial vacuum above the bath and heating the bath with the article therein till the article is partially carbonized, and relieving the vacuum above said bath.

The herein described method of treating articles composed of woody material to render the same water, acid, and alkaliproof. which consists in immersing the 'article in a bath of resistant material, producing a partial vacuum abovethe bath an d heating the bath till the article therein 15 partially carbonized, and relieving the racuiun and lowering the temperature of the bath.

(S. The herein described method of treating articles composed of woody material to render the same water, acid, and alkaliproof, which consists in immersing the article in a bath of water-proof and resistant materiatliquefied by heat, partially .carbonizing the woody material of the article while in the loath and permitting the liquefied material of the bath to permeate the partially carbonized article, then removing the article from the bath and allowing the absorbed material of the bath to harden by cooling.

ISAIAH L. ROBERTS.

Jnssn PETERSON,

CHAs. E. Fomna.

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