US645080A - Process of paper manufacture. - Google Patents

Description

Pat'ented Mar. l3, I900.

F. A. FLETCHER.

PROCESS OF PAPER MANUFACTURE.

(Application filed June 26, 1899.)

(No Model.)

WITNESSES:

ATTORNEY m: uomvs were: co. nowmmu. wumNuToN. 0, c.

NTTED Sma ties FRANK A. FLETCHER, OF VATERTQWVN, NEW YORK, ASSIGNOR TO THE AERATED PAPER COMPANY, OF NEXV YORK, N. Y.

PROCESS OF PAPER MANUFACTURE.

SPECIFICATION forming part of Letters Patent No. 645,080, dated March 13, 1900.

Original application filedApril 20, 1899, Serial No. 713,699. Divided and this application filed June 26, 1899. Serial No.

721,810. (No specimens.)

To aZZ whom it may concern.-

Be it known that I, FRANK A. FLETCHER, a

citizen of the United States, residing at Wa-' tertown, Jefferson county, New York, have invented certain new and useful Improve ments in Processes of Manufacturing Paper, of which the following is a full, clear, and exact description.

This invention relates to the manufacture of paper, and particularly to a new process therefor, this application being a division of a former application serially numbered 713,699, filed April 20, 1899.

The object of this process is to obtain a product of a soft, porous, and highly-absorbent nature.

In describing the process I will briefly allude to an apparatus (such as described in detail in the referred-to original application of which this is a division) as illustrative of one form of apparatus by which such paper may be produced. To that end, therefore, the accompanying drawing illustrates a vertical sectional view of a preferred form of apparatus, parts of the same being only indicated.

The product in this process may be made from almost any kind of stock possessing a suitable fiber, especially soda-pulp. The fiber is reduced to a pulp, and as I desire to produce a paper which is soft and extremely porous I prefer not to subject the pulp to pressure before I treat it, as hereinafter described.

In the accompanying drawing I have shown the sheet of paper formedby a cylindermachine, but do not desire to limit myself to that method of forming the sheet.

A is a vat that contains paper-pulp, a being an inlet for the same, and a an outlet for the Water from a revolving cylinder-mold B. This mold is preferably hollow and covered with wire-cloth or other suitable material, and upon it is deposited the paper strip or pulp in the well-known manner.

0 is a couch-roll, and D a roll over which and over suitable intermediate supporting or carrying rolls (1 d may pass a conveyer-belt E, preferably in the form of an endless strip of wire-cloth or other suitable material.

The rolls 0 and D and cylindenlnold B are suitably rotated in the direction of the arrows. The paper-pulp strip is formed upon the mold B and taken up by the wire-cloth in the manner understood in this art and carried byit in the form of a continuous strip F of the desired thickness.

When I speak of a strip of paper-pulp, I do not mean that the pulp must necessarily be made from paper, but only that it is a pulp which will form a paper, and, further, I do not mean that the paper of the strip must necessarily be in the condition that it is when it comes from the cylinder-mold; but this latter or substantially this is preferable.

The wire-cloth belt allows some of the water in the strip to drain away, and the belt preferably passes over suction-boxes G G, which extract from the strip a portion of the remaining moisture. The belt may then pass overa suitable drying means,such as heatingboxes H, located in any suitable position and heated by anysuitable means. After leaving the,.ro1l D the paper maypass to a conveyer K and out through an'air-lock aperture L to rolls M, ifdesired. As the wire-cloth belt and the strip of paper pass the heatingboxes the paper will be partially dried. To accelerate this drying and to produce other advantageous results, I subject the paper strip while still moist to the action of a rarefied atmosphere and preferably to heat at the same time. This may be accomplished by passing the strip through a heated chamber from which the air has been exhausted to any desired degree. wet or moist from the vat, I rarefyithe air within the chamber by any suitable meansfor example, the pump O- thus lowering the boiling-point of the water in the strip, and as said strip passes the heating-boxes this water or some of it is preferably turned into steam bubbles, which force apart the particles of the paper strip and which, if theheat is continued, finally evaporate, producing an ex- As the paper strip comes 1 tremely soft, porous, and highly-absorbent vert the water in the strip into steam, because if the heat is only enough to evaporate the water without first converting it into steam a paper will result having these characteristics to a certain extent; but the paper will not be so porous as it would be if the water were converted into steam, as aforesaid. One important advantage of rarefyingthe air in the heating-chamber is that such a high degree of heat is not required to convert the water in the strip into steam or to otherwise evaporate it as would otherwise and usually be the case. This materially lessens the danger of injuring the paper strip by a too great degree of heat, which might degrade the color or strength of the product. In this way I can produce, if desired, a continuous strip of soft and extreme1y-porous, consequently highlyabsorbent, paper without resorting to the common expedient of compression. The process, therefore, mainly consists in forming a sheet of moist paper-pulp Within a substantially-closed chamber and of rarefying and heating the air around the sheet to drive off some of the moisture therefrom.

It will be obvious that many changes may be made in the process herein disclosed without departing from the spirit of my invention.

What I claim is- 1. The process of manufacturing paper which consists in forming a sheet of moist paper in a substantially-closed space and rarefying and heating the air in said space to drive off some of the moisture from said sheet, th ereby producing a soft and porous paper.

2. The process of manufacturing paper which consists in forming a sheet of moist paper-pulp in a rarefied atmosphere and heating the same to drive off some of the moisture therefrom to substantially dry said strip without substantial compression, thereby producing a soft and porous paper.

3. The process of manufacturing paper which consists in forming a strip of moist paper-pulp in a rarefied atmosphere and heating the same to assist in driving 0E the moisture from said strip, and substantially drying said paper without substantialcompression of the same, thereby producing a soft and porous paper.

4. The process of manufacturing paper which consists in forming a strip of moist paper-pulp in a rarefied atmosphere, applying heat to the same to drive off some of the moisture therefrom, and passing said sheet back and forth through said heated and rarefied atmosphere to substantially dry said strip without substantial compression of the same, thereby producing a soft and porous paper.

5. The process of manufacturing paper which consists in forming a continuous strip of moist paper-pulp in a rarefied atmosphere, extracting by suction some of the moisture from said strip, applying heat to said strip to drive off some of the moisture therefrom, and passingsaid strip through said heated and rarefied atmosphere until the same is substan tially dry, Without substantial compression of the same, thereby producing a soft and porous paper.

Signed at New York, N. Y., this 21st day of June, 1899. I

FRANK A. FLETCHER.

Witnesses:

EMERSON R. NEWELL, L. VREELAND.

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