US1514556A - Paper-making- machine - Google Patents

Description

New. 4, 1924. 1,514,556

7 v 1.1.1:. MILKEY PAPER MAKING IACHINE' "PARTICULARLY ADAPTED TO MAKING TISSUE AND OTHER THIN PAPERS -Filed March 25. 19225 2 Sheets-6h! 1 ll ll l Nov. 4 1924. 1,514,556

E. MILKEY L. PAPER MAKING MACHINE, PARTICULARLY ADAPTED TO MAKING TISSUE AND OTHER THIN PAPERS Filed March- 26, 1923 Sheets-Sheet 2 ZemerZC/Vilkgy.

Patented Nov. 4, 1924.

UNITED STATES PATENT OFFICE;

Ems n. Imam or sANnnsKY, onto.

i fii iiin-itiiiizine madman, renrxonnnnrrn iilrrun To MAKING 'rIsslr irE AND I I OTHER THIN r'ArERs.

t pnct an filed March 26, 1923. $eria1 no. 627,902.

To, all whom it may ooncemifl Be it known that 'I, Liesrnn ERNEST Mri'lniir, a citizen of the United States, residing-at S'andusky, in the county of Erie and State of Ohio, have invented a new and useful Papers raking Machine, Partic ulaifly j A'daptedi to Making Tissue and Other Thin Papers, of which the followingis P 1 61 "tha a: a a

,iiivehtioii relates to an improved pa t erhnaking machine it is my object to provide a niachihe so constructed and arranged as to be particularlv adapted to makingtissue and other thin papers; and to provide a paper-making machine in which theweb 'of paper continuously supported or carried from the time it is formed until it passes through the first press rolls and reaches a dry enough condition tosupport itself in its further passage through the paper-making machine Iattain these and other ob ects of my inventlon by the mechanism illustrated in the accompanying drawings,in. Which a I Figure l is one form'of my invention and Fig. 2 is another form of my invention incorporating a device which I have heretofore patented No. 1;387,061. A Y

Like numerals designate like parts in each of the views; 1

Referring to the accompanying drawings I provide a tank 1 containing a supply of pulp 2whicli is fed bn the endlessscreen 3, this screen 3 trayersing a drum 4:, asuotio'n roll 5 and idle rollers 6, as shown in Fig. 1. I provide a suction box 7 underneath screeii 3 to draw water out of the pulp. I

further provide aI n1et'al upper press roll'8" in operative contact with the wire screen unde 'r'o'll SI provide the lower press roll 9 having a rubber cover'ed surface 10 Over whichtravelsthe endless p felt 11! this felt beiiig guided ever the suitably arranged felt rollers 12. I provide a suitable suctioii lio'ii 13 forthe endless-press felt 11, as shown in both" figures. I provide, a drip pan 14 Positioned above the metal upper press roll 8 I may provide a doctor blade 15 for the, purpose of creping the paper.

3 is supported.

I provide a paper carrying roll "21 in proX- imity to the metal upper press roll 8.,to receive the paper as it passes over that roll and I also provide a conventional or baby dryer roll 16 beyond the paper carrying roll 21 I further provide the standard first dryer 17 and endless dryerfelt 18 passing over the felt rolls l9. I provide a suitable blow pipe 20 in proximity to the metal upper press roll 8-and to one of the idle rollers 6 to loosen the paperfrom the wiret screen 3 so that it will pass around the roll 8 as indicated in the drawings. \Vhile I may use the air blast to loosen the sheet in start.- ing up the machine, in most cases I do not need it or use it at all, for the smooth sur-. face of the press roll has a greater aflinity for the paper web than has the wire screen. Therefore, the paper web clings to and fol-. lows the surface of the press roll andina smooth flat condition without wrinkles or bubbles. "With thearrangement disclosed the paper web does not remaihunsupported at any time and therefore cannot break, as is possible with the machines of the prior Referring to Fig. 20f the drawings, there are illustrated suitable d'eckles22 on opposite sides of the rollers 23 toconfine the flowing pulp and 'sodetermine the width of the paper. In this form of the invention the l wirejscreentravcls over a breast roll. 24 and the idle rollers 25. I provide a plurality of idle supporting rollers 25, spaced a suit able distance apart, on which the wire screen I prefer to provide also the revolving blow roll 26 which I have heretofore patented and also I provide a suitable drip pan 27 beneath the revolving blow roll 26 As indicated in beta Figures "1' as .2, 2e

indicates the point Where th'epulp is fed onto the Wire screen 3; 29 indicates the point where the paper leaves the wire screen 3 and passes-part way round the metal upper press roll 8, leaving that elementat the oint 30 where it passes to the paper carrymg roll 21 and thence aroundthe conventional or baby dryer roll 16, and thence into I the standard first dryer 17.

It is Well known that paper making maof paper frequently and easily breaks on account of its strength not being sufficient to carry itself from one to the other unsupported. In attempts to overcome this some adaptations of the regular Fourdrinler a er makinq'machine have been made p 2 In these as in the others, the moist web f paper is picked or couched off from the wire screen by a first press top or bottom felt which, through the use of a couch or press roll, is made to come lnto contact with and press against the wire screen with the web of paper between. This felt picks up the web of paper and'then carries it through the first-press rolls. This method has several serious disadvantages which limits its use ver 7 much.- One of them is that the picking off felt absorbs considerable water during its contact with the wet wire screen and paper web and it then becomes extremely difficult if not impossible to use enough pressure between the press rolls to obtain the requireddryness of the paper web or sheet without crushing the latter-due to the large quantity of water already carried by the felt itself, The felt when already very wet can not take up and absorb the additional water that ispressed from the paper web by the actionof the press rolls and consequently the paper web suffers what is known to the trade as crushing. Moreover, the felt under these conditions, rapidly fills up and becomes dirty and in order to be useful at all, re-' quires constant and severe washing and beating, all of which is detrimental to the life of the felt. On some of these machines the felts last only a few days indicating the great expense involved.

Another disadvantage to this'arrangement is that the felts must be made of a character suitable .for picking 'up the web of paper.

And to do this requires that thosecharacteristics of the felt which are best suited for the primary purpose of absorbing the water as it is pressed out of the paper web by the tained Water, is then transferred directly onto the non-absorbing and bare surface of the upper press roll by causing the same Wire screen upon which the paper is formed, to bear against a part of the circumference of the upper press roll as shown. The smooth surface of the press roll, ordinarily made of metal, has greater affinity for the moist paper web than has the wire screen, and the paper web or sheet therefore adheres to the metal roll and is automatically carried along with it and then between the first press felt and the upper press roll to be pressed at the bite or pinch of the press rolls in the orthodox way.

Sometimes when this paper machine is started up or when making certain grades of paper it is desirable to use a blast to gently free the paper web from the wire screen just as the latter makes or departs from its contact with the upper press roll. This is indicated on the drawing. The upper press roll is also in some instances steam heated for the purpose of still further caus ing the moist paper to transfer to and to adhere to it. Heating the top press roll serves the further purpose of warming up the moist paper in which condition it gives up its water more readily while being pressed.

From the surfaceof the upper press roll and after having passed through the press rolls, the web of paper is then sufficiently dry to support itself and is led over rolls as shown and usually into the'dryers as on an ordinary paper machine. Or if it is desired to produce a crped paper, a doctor blade is used as shown to scrape the paper sheet free from the surface of the upper press roll.

The formation of the paper web itself may take place in any of several ways, two of which are shown by the drawings. In any case, however, the paper web is formed on an endless wire screen.

With my invention the first press felt has no opportunity to absorb water except that pressed out of the paper as it passes through the bite of the pressrolls and this is the primary and all important purpose of any paper machine press felt. The felt does not, therefore, need to be specially made or napped to give it the picking up qualities so necessary on present machines of the Harper or similar type, but can be best made to ful; fill its single purpose of absorbing water at the pressing operation by the press rolls, The press felt thus has greater length of life and does not require constant and destructive washin Another advantage of my invention is that the paper itself is pressed much drier so that it can be handled at that point on the machine with very little danger of breaking. And the paper being drier, less steam is necessary to finish drying it. Prior to the pressing operation, the paper web cannot a CD break regardless of the voperating speed of the machine and what is known asthe wet end of the paper, making machine thenbecomes largely auttnnati'c. Inother words I have provided a papeiu making machinev in which the recognized advantages of forming a web of paper on an endless wire screen can be utilized iii. making very thin papers because of the elimination of the usual gap between the wire screen and the first press felt on such machines which the paper must span unsupported. And this is accomplished without bringing the felt itself into contact with the wire screen just mentioned.

The upper metal press roll may be either steam or otherwise suitably heated or a cold roll, and the diagrammatic illustration is in tended to include the disclosure of either a cold roll or a heated roll, having suitable and appropriate means for heating same.

What I claim is:

1. In a paper making machine, the combination of a pair of engaging press rolls of the conventional type, and means sup porting and directly transferring the newly formed web of paper on to the bare surface of the upper press roll from the endless wire screen upon which the paper web was formed.

2. In a paper making machine, the con bination of an endless wire mesh screen upon which the paper web is formed, a pair of engaging press rolls and means for bringing said wire screen with the moist paper web on it into contact with the bare surface of the upper press roll prior to its being pressed or squeezed in the conventional way.

3. In a paper making machine, the combination of a pair of engaging press rolls, an endless felt or apron passing around .the lower one of said press rolls, means for sup porting and transferring the moist web of paper from the endless wire screen upon which it was independently and previously formed directly on to the surface of the upper press roll prior to its passing through the bite of the press rolls.

4. In a paper making machine, the oombination of a pair of engaging press rolls, an

endless felt or apron passing around the lower one of said press rolls, means for directly transferring the moist web of paper from the endless wire screen upon which it was independently formed to the bare surface of the upper press roll by bringing said wire screen into contact with said upper press roll, substantially as shown.

5. In a paper making machine, the conr bination of an endless wire screen upon which the paper web is formed and by which it is supported, a pair of engaging press rolls, one of said rolls being in operative contact with the endless wire screen, means for directing an air-blast through the wire screen at a point where it separates from the press roll with which it contacts to l v the paper web from the wire, screen-and transfer it directly to the baresurface of the press rolls, substantially asshown.

6. In a paper making inacl'iine, the com;

bin-ation of an endless wire screen .upon which the; paper web is formed and, by. which it is supported, a pair of engaging press rolls, the upper press roll being heated, one of said rolls being in operative contact with the endless wire screen, means for olirecting an air-blast through the wire screen at a point where it separates from the press roll with which it contacts to loosen the paper web from the wire screen and transfer it directly to the bare surface of the press rolls, substantially as shown.

7. In a paper making machine, the co1nb? tion of an endless wire screen upon which the paper web is formed and by which it is supported, a pair of engaging press rolls with one of which the endless wire screen contacts, and to which the paper is directly transferred, an endless felt engaging around the lowerv press roll and in contact with the upper press roll, and means for extracting moisture from the endless press felt prior to its passing into the bite of the press rolls.

8:111 a paper making machine the combination of an endless wire screen upon which the paper web is formed, a pair of engaging press rolls, the endless wire screen being arranged to support the paper and transfer it directly to the upper press roll, the ripperpress roll being heated, and a doctor blade in operative engagement with the upper press roll for crping the paper on the heated upper press roll.

9. In a paper making machine, the combination of a pair of engaging press rolls, an endless wire screen uponwhich the moist paper web is formed, said endless wire screen carrying the moist paper web into direct contact with a portion of the surface of the upper press roll, means for directing a blast of air through the screen at the point where its contact with the upper press roll ends to cause the paper to adhere to the upper press roll, endless press felt extending around the lower press roll, means for extracting moisture from said endless press felt prior to its passing throughthe bite of the press rolls, a paper carrying roll positioned in proximity to the upper press roll at the opposite side from the endless wire screen for guiding it to the drier mechanism of the machine.

10. In a paper making machine, the combination of a pair of engaging press rolls,

an endless wire screen upon which the moist liS tion of the surface of the press r011 means for extracting moisture from the paper web as it passes over the endless wire screen prior to its contact with the upper press roll,

' means'for directing a blast of air through the screen at the point Where its contact with the upper press roll ends to cause the paper to adhere to the upper press roll, an endless press felt extending around the lower press roller, means for extracting moisture from 1 the endless wire screen for guiding it to the 15 drier mechanism of the machine.

LESTER E. MILKEY.

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