US1883022A - Paper making process - Google Patents

Description

7 No Drawing.

Patented Oct. 18, 1932 j UNITED STATES JAMES R. SIMPSON, OF WISCONSIN RAPIDS, WISCONSIN,

WORKS, OF BELOIT, WISCONSIN, A CORPORATION OF WISCONSIN PAPER MAKING PROCESS Application filed June 18,

The present invention relates to a paper making process and more particularly to those steps in the process of making a sheet of paper involving the formation of the sheet on the wire of a F ourdrinier paper making machine.

In such formation of a sheet of paper, it has heretofore been found desirable in making many grades of paper to effect a vibratory or shaking motion in that part of the machine including the Fourdrinier wire in order to interlace and evenly distribute the fibers from which the sheet is formed.

In paper making processes as heretofore practiced, this shaking application has been applied ordinarily beginning at a point where the stock flows onto the Fourdrinier wire or immediately thereafter and without reference to the condition of the stock or the speed of formation of the sheet. By such former processes, control of the formation of the sheet has been haphazard and in many instances the shaking action has been found to be detrimental rather than advantageous.

By the present invention I propose to overcome such difliculties and control the formation of the sheet so far as the shaking of the fibers in the stock from which the sheet is formed is concerned by only applying the shake beginning at that portion of the F ourdrinier wire where a certain portion of water has drained from the stock and the fibers from which the sheet is forming have already taken an initial set in the formation of the final sheet. I have found that at this point the shaking action is desirable and necessary to smooth out and strengthen the fibrous formation while application of the shake or vibration at points in advance thereof may often prove detrimental.

By utilization of this principle, it is possible to make a sheet of relatively high grade paper at extremely high speeds and without special preparation of the stock by beating or otherwise and the attendant tendency to weaken the sheet formation by deterioration of the fibers from which the sheet is formed.

As an example of the application of the principles of this invention, I have found it 1930. Serial no. 462,144.

possible to make relatively high grade magazine paper in a Fourdrinier machine at speeds approximating one thousand feet per minute from stock of approximately sixty percent ground wood and forty percent bleached sulphite with no special preparation of the stock and no use of beaters, the stock soused comes from the pulp mill over deckers and is slushed through a light running Jordan engine directly into the head box of the machine and onto the Fourdrinier wire. This particular grade of paper has a base weight of AssI GNoR TO BELOIT moiv approximately thirty-five pounds and due to the fact that there is so much water in thestock when it first flows on the wire, the stock does not form immediately, and therefore, in accordance with the principle of this invention, I have found it most advantageous to apply the shake approximately at the center of the F ourdrinier wire at a rate of about 350 to 400 vibrations per minute and at an amplitude of about three-eighths inch." In making heavier paper, the shake is applied nearer to the breast roll of the Fourdrinier paper making machine but in all instances the shake is not applied in advance of the point where sufiicient water has drained through the wire to bring about an initiation of the formation of the fibers. At this point, the application of a shaking action has been found by me to be most advantageous in the formation of a strong, uniform and superiorsheet of paper at high rates of speed. By so applying the shaking action in the formation of the sheet, it is possible to leave the fibers of the stock longer and consequently the completed'sheet of paper has a better test as to tearing and as to folding qualities. 7

In carrying outthe process of this invention, I have found it advantageous to employ a shaking mechanism such as disclosed in United States Letters Patent No. Re. 17,381, reissued on the th day of July, 1929, to Alonzo Aldrich. This mechanism is convenient for the practicing of the process of my invention because of its ready adaptability for connection of the shaking mechanism at various points along the Fourdrinier wire and the disconnection of the shaking mechanism from those portions of the wire which it is not desirable to shake.

In accordance with the process of the present invention, the shake is not applied until the stock has flowed on the wire and reached such a condition that the shake becomes effective in properly smoothing out the fibrous formation. By virtue of this fact, preliminary working of the fibers as by beating is greatly minimized.

As a general thing, it may be stated'that jhe vigorous shake should be applied approx fiber formation during a substantial distance of travel on a portion of the wire free from lateral movement and applying a vigorous shaking action to the stock after said initial fiber formation to efiect proper distribution and interlacing of the fibers in the sheet being formed.

In testimony whereof I have hereunto subscribed my name at Wisconsin Rapids, Wood County, Wis.

JAMES R. SIMPSON.

lmately at the center of the Fourdrinier wire for the lighter weights of paper while for in that the stock is not shaken until some water has been drained therefrom and furthermore the life of the Fourdrinier wire is lengthened due to the fact that in practically all instances the wire is reciprocated across the faces of the suction boxes'and is not worn out by grooves formed therein.

In general I may state that in applying the principles of this invention in stock of heavier consistency the shake is initiated closer to the breast roll while with stock of li hter consistency the initiation of the shake I o 0 1s brought about at greater distances from the breast roll as previously pointed out herein.

I am of course aware that details of practicing the process of my invention may be varied and thatthe process may be effected by various mechanisms, and I therefore do not purpose limiting the patent granted upon this invention otherwise than necessitated by the prior art.

I claim as my invention: 7

1. The method of forming a paper web which comprises flowing paper stock onto a traveling perforated surface, draining a predetermined quantity of water from the stock without substantially shaking the fibers.

therein to form an initial deposit of loosely matted fibers on the perforated surface under relatively quiescent conditions, and subsequently subjecting said deposited fibers to a shaking action to forms an interlaced fiber we 2. In the process of making paper at high speeds on a Fourdrinier type of paper machine having a forming wire, the steps which compriseflowing the paper stock onto a traveling Fourdrinier wire,=permitting an initial