US1898611A - Method of and apparatus for making paper - Google Patents

Description

Feb. 21, 1933. E. E. BERRY ET AL METHOD OF AND APPARATUS FOR MAKING PAPER 2 Sheets-Sheet l Filed June 27, 1951 Feb; 2l, 1933.

E. E. BERRY ET AL METHOD OF AND APPARATUS FOR MAKING PAPER 2 Sheets-Slxee'cl 2 MFE/j; afl 361719, eodofe 6. ans.

y @QL Filed J-une 27, 1931 Patented Feb. 2l, 179-33 UNITEDJ STATES PATENT ori-'ICE EARL E. BERRY AND THEODORE C. ROBERTS, 0F BELOIT, WISCONSIN, ASSIGNORS TO BELOIT IRON WORKS, 0F BELOIT, WISCONSIN, A CORPORATION 0F WISCONSIN' METHOD APPARATUS FOR MAKING PAPER Application led June 27,

This invention relates to a method of and apparatus for makingpaper and more particularly to the use of a resilient covered suction roll asa pressure or transfer roll, more especially in connection with the manufacture of tissue or other light weight papers.

It has heretofore been customary in the manufacture of paper, and more particularly in the manufacture of tissue or other light weight paper, to use a pick-up type of felt for transferring the paper web from the forming part of the machine to a transfer roll or directly by means of a pressure roll to a drying cylinder. Ordinarily, light weight papers are made upon either a Yankee or Harper F ourdrinier, or upon a cylinder machine. The Yankee machine is used for making what is known as machine glazed, or M. G., paper and is equippedeither with a Fourdrinier forming portion or a cylinder. In either case, a pick-up type of felt carries the moist web of paper from the forming portion to the single large drier that is characteristic of this type of machine. Where the machine is equipped with'a plain bottom couch, the top felt passes between the top couch and the bottom couch to lift the sheet from the wire and then carries the wet web of paper on through the presses and passes between a pressure roll and the drying cylinder, the pressure roll serving to transfer the web of paper from the felt to the surface of the drier. chine necessarily has to be equipped with a bottom felt in order to get the sheets through the presses but after passing through the presses, the bottom felt parts from the top felt and leaves the sheet adhering to the top felt. p In a Harper Fourdrinier machine, equipped with a plain bottom couch, it is customary for the top felt to pass under the top couch to pick up the moist web of paper from the forming wire and carry it back over the forming portion of the machine to a transfer roll, where, by means of a pressure roll, the web of paper is transferred from the'felt to the transfer roll and then picked up from the transfer roll and carried over into the driers.

The arrangement of a cylinder machine is often quite similar, with the pick-up felt car- 1931. Serial No. 547,215. y

rying thel web of 'paper either to 'a transfer roll or dlrectly to the drier cylinder, with a pressure roll to effect the transfer ,of the web from the felt to the transfer roll or to the up of water that has been squeezed from thev sheet in back of the nip between the two rolls.

As is well known to those skilled in the art,

this condition results in a crushing of the wet web of paper and also leaves the web wetter than it should be at this point.

The present invention contemplates the correction of vthe improper conditions referred to by the use of a suctiofi pressure roll to suck the nip dry and eliminate the crushing. rThe use of the suction roll at this point, furthermore, greatly lengthens 'the life of the pick-up felt, since itvprevents the felt from filling up, an effect that has heretofore commonly resulted from the crushing at the nip. A suction pressure roll at this point also has the added advantage of producing a drier sheet. Y'

Where the suction `roll of our invention is used as a pressure and transfer roll for transferrlng the wet web of paper directly to the large drying cylinder of a Yankee machine, we find that the efficiency of the suction roll is much greater then when a suction press roll'- is used in the customary way in conjunction with a plain top press roll. This greater efliciency is doubtless due to the fact that when the wet sheet is applied at high pressure against the heated surface, there is an instantaneous transfer of heat from the drier to the sheet of paper that materiall lowers the viscosity: of the water in the siieet and thereby causes the paper fibers to give up their water more freely than in the usual arrangement of a suction press roll cooperating with an unheatedtop roll.

Moreover, the use of a suction pressure roll nation alone means a tremendously large saving.

It is therefore an object of this invention to provide a novel means and method for making paper, and more particularly light weight paper, on types of paper making machlnes that require the use of a pickup felt.

It is a further important object of this invention to provide a novel and improved construction of suction roll for use as a pressure and transfer roll in the manufacture more particularly of light weight papers.

It is a further important object of this invention to provide a resilient covered suction pressure roll for cooperation with the pick-up felt of a paper machine for transferring the wet web of paper from the felt to a transfer roll or to a heated drier cylinder.

It is a further object of this invention to provide a novel combination of means including a resilient suction roll in connection with the manufacture of light weight papers and tissues that eliminates the necessity of using a bottom felt.

Other and further important objects of this invention will be apparent from the disclosures in the specification and the accompanying drawings.

This invention (in a preferred form) is illustrated in the drawings' and hereinafter more fully described.

On the drawings:

Figure 1 is a diagrammatic view of a cylinder typ'e of Yankee machine equipped with a suction press roll of our invention.

Figure 2 is a sectional view of the suction pressure roll of our invention.

Figure 3 is a diagrammatic view of the Fourdrinier type of Yankee machine equipped with a suction pressure roll.

Flgure 4 is a diagrammatic view illustrating the use of a suction pressure roll on a.

Harper Fourdrinier machine having a creping attachment.

As shown on the drawings:

The reference numeral 1 indicates a cylinder vat of usual construction having a forming mold or cylinder 2 therein. In a manner well known to those skilled in the art, the

web of paper formed on the cylinder mold 2 is transferred by means of a couch roll 40 to a felt 4. Said felt 4carries the wet web of paper vinto the nip between a drying cylinder 5 and a pressure roll 6, which latter roll effects the transfer of the web of paper from the felt to the surface of the drier drum. As illustrated in Fig. 1, the drier cylinder 5 constitutes the usual, large diameter drier of a Yankee machine.

In accordance with our invention, the pressure roll 6 is a suction type of roll, preferably of the novel and improved construction shown in Figure 2. Said roll comprises a perforated metal shell 10 having an inner, longitudinally extendin suction chamber 7 connected at one or bot ends to a suitable source of suction (not shown). Said chamber 7 is provided with a pair of s acedianges 41 extending substantially the ull length of the chamber and thereby providing l'an opening 8 from the interior of the chamber radially directed toward the inner surface of the shell 10. A floating head 9, mounted from said anges 41, is provided with lengthwise extending packing strips 42 and end packing strips 43 that are pressed against the inner surface of the shell 10 in a manner described and claimed in the U. S. patent to Berry No. 1,679,598 issued August 7th, 1928.

Up to this point, it will be understood that the construction of the suction pressure roll 6 may be either as described or may be modified in accordance with well known practice, since the specific features of construction thus far described form no part of the present invention.

The usual type of metal suction roll cannot, however, be successfully used for the purposes of this invention insofar as it applies to the making of light weight and tissue papers on the types of paper making machines lierein shown and later described. If the usual perforated metal suction roll were used in lace of the suction pressure roll 6 of our invention, inequalities of pressure would be unavoidable due to the impossibility of accurately grinding the surfaces of the metal suction roll and the drier drum or other metal roll to which the web of paper is to be transferred. Consequently, it would be impractical, if not impossible, to employ the usual type of metal suction roll in connection with the manufacture of tissue and other light weight papers for the purposes herein set forth.

Accordingly, the suction pressure roll of our invention is provided with a resilient covering 12 made of some suitable cushioning material, preferably rubber. Said resilient covering 12 is suitably in t-he form of a continuous sleeve of rubber of appropriate density, such as that of the usual rubber covered press roll. The rubbersleeve is secured to the outer surface of the shell 10 in any suitable manner, as by vulcanizing, cementing or by the so called Vulcalock process. After assembly of the sleeve 12 upon the shell, corresponding perforations 13 in the sleeve are made to those in the shell 10, or, the assembled composite shell is drilled to form the perforations 11 and 13 at the same time or 'the shell may be perforated before assembly and a correspondingly perforated sleeve applied thereto.

With a suction pressure roll such as described, positioned as at 6 in the paper making machine diagrammatically shown in Figure 1, said roll serves both as a suction roll to remove water from the wet web of paper on the felt 4 and also as a pressure and transfer roll to transfer the web of paper to the surface of the large drying cylinder 5. The suction opening 8' is preferably directed against the web a slight distance in advance of the nip of the rolls so that the web is acted upon by the suction before being pressed between the roll and drum. This action aids in the subsequent delivery of the web by the felt to the drier. drum. The provision of the resilient covering or shell 12 eliminates any tendency to crush the sheet as it passes into the nip between the roll 6 and the drying cylinder 5.

As previously pointed out, the use of a suction roll at thispoint, coacting with the heated drier cylinder, not only sucks the nip dry but also results in greatly improved eteiencies over the use of the usual type of suction press roll in association with a plain, unheated top roll. The heat from the drying cylinder 5 instantly heats the water contained in the web of paper pressed in contact therewith by the suction roll 6 and thereby reduces the viscosity of the water to such an extent that it is pulled much more readilythrough the web of paper and accompanying felt by the suction action of the roll 6 than would be the case were the web lnot heated while being acted upon by the suction roll.

In Figure 1 there is also shown 4a second suction roll, indicated by the reference numeral 6a, ahead of the suction roll 6 for effecting a preliminary removal of water fromthe felt and webcarried thereon. The suction roll 6 may be of standard construction and need not have a resilient covering such as the suction pressure' roll 6 of our invention.

In Figure 3 .there is illustrated diagrammatically aA Fourdrinier type of YankeeV paper machine comprising a Fourdrinier forming portion 16 having the usual endless forming wire 15 associated therewith. Stock flows from the head box 14 ontok the forming wire 15 and passes over the usual table rolls and suction boxes to the couch end of the table structure. As the partially formed web of paper on the wire 15 passes over a lower couch roll'19, a top felt 18 is brought` into contact with said web of paper by means of an upper couch to pick up the to press the felt 18 against the surface of the drier drum 21 and effect the transfer of the web of paper from the felt to the surface of the drier drum. The functions of the suction pressure roll 22 are the same as those already described above.

In Figure 4 there is shown a Harper type of Fourdrinier paper making machine, indicated generally by the reference numeral 44. A top felt 45, coacting with a top couch 46, picks up the web of paper from the forming wire 47 as it passes around the lower couch roll 48. As is characteristic of this type of machine, the top felt 45 extends back over the forming wire 47 and serves to carry the web of paper, in the installation illustrated, to a heated cylinder 49 with which is associated a creping doctor 33. A suction pressure rollv 24, of the same construction as that above described, serves to transfer the wet web of paper from the top felt 45 to the surface of the heated cylinder 49. Rotation of the cylinder 49 carries the web of paper up against the creping doctor 33, bymeans of which the paper is given the desired creped effect. From the creping doctor 33, the creped, still 'moist web of paper is carried over into the nip between the bottom drier felt 50 and the first bottom drier drum 51 of the drier section 25. A

It will be noted that each of the various types of paper making machines illustrated herein are particularly adapted for the manufacture of tissue or other light Weight papers and it is in connection with these types of machines that the resilient covered suction pressure roll of our invention 4finds its greatest utility.

In the preferred embodiment of our iny up type of felt, or top' felt, and for transferring the paper web from the felt to a heated drying cylinder. In such anarrangement, suction pressure rolls of our invention `have peculiar utility in that they provide improved means for transferring the paper from the felt to the drying cylinder and also for removing water from the paper web. The elimination of the use of a bottom felt, as is ordinarily necessary in this type of installation, constitutes in itself a considerable saving which results directly from the use of suction pressure rolls of our invention.

We are aware that many changes may be made and numerous details of construction lmay be Varied through a Wide range without departing from the principles of this invention, and we, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

We claim as our invention:

l. In combination with a metal surface roll, a pick-up type of felt for conveying a moist web of paper into contact with said roll and a suction roll having a cushioned surface in pressure relation to said metal surroll and to remove water from said web and felt.

3. In combination with a metal surface roll, a pick-up type of felt for conveying a moist web of paper into contact with said roll and a rubber covered suction roll in pressure relation to said metal surface roll with said felt therebetween to transfer said web of paper to said metal surface roll.

4. In a paper machine of the type including a top felt for transferring a moist web of paper from the forming portion to a heated drying cylinder, a resilient surfaced suction roll urged into pressure relation with said heated drying cylinder with said felt and web therebetween to transfer said web of paper to said drying cylinder and simultaneously withdraw waterfrom said felt and we 5. In a paper machine of the type including a top felt for transferring a moist web of paper from the forming portion to a heated drying cylinder, a perforated rubber covered suction roll urged into pressure relation with said heated drying cylinder with said felt and web therebetween to transfer said web of paper to said drying cylinder and simultaneously withdraw Water from said felt and web.

6.V In combination, a roll having heated metal surface, a suction pressure roll having a cushioned perforated surface urged theretowards and a traveling felt for carrying a moist web into the nip etween said rolls into contact with said heated metal surfacefor transfer thereto.

7. In combination, a roll having heated metal surface, a suction pressure roll having a cushioned perforated surface urged theretowards, a traveling felt for carrying a moist web into the nip between said rolls into contact with said heated metal surface for transfer thereto and a stationary suction chamber within said suction pressure roll acting through said perforated surface slightly in 'advance of said nip to remove water fromsaid felt and web.

8. In a Fourdrinier type of Yankee paper machine including a forming portion, a drier drum and a pick-up felt for transferring the machine including a cylinder mold, a drier drum and a pick-up felt for transferring the web of paper from said cylinder mold to said drier drum, a suction pressure roll associated with said felt and drier drum to transfer said paper web to the surface of said drier drum.

10. In a Harper Fourdrinier paper machine, a suction pressure roll associated with the top felt and a heated cylinder for transferring a web of paper carried by said felt to the surface of said heated cylinder.

11. In a. Fourdrinier type of Yankee paper machine including a forming portion, a drier drum and a pick-up felt for transferring the web of paper from said forming portion to said drier drum,.a suction pressure roll havingA a perforated rubber covering associated with said felt and drier drum to transfer said paper web to the surface of said drier drum. y

12. In a Harper F ourdrinier paper machine, a suction pressure roll having a perforated rubber covering associated with the top felt and a heated cylinder for transferring a web of paper carried by said felt to the surface of said heated cylinder.

13. The method of making paper, which comprises passing a moist web of paper while adhering to a porous textile surface into contact with a traveling heated metal surface and resiliently pressing said paper web against Said metal surface totransfer said web thereto while simultaneously subjecting said web of paper immediately in advance of said contact to suction.

14. The method of making light weight paper, which comprises conveying a moist 'web of light weight paper on a pick-up felt into close proximity to a revolving heated metal surface, resiliently pressing said felt toward said heated surface to bring said paper web into contact therewith for transfer thereto andA simultaneously subjecting said felt and web to suction immediately in advance of the contact between said paper web and heated surface. p

15. The combination with a paper making machine including 'web-forming means, drying means, a single felt for carrying the web from the forming means to the drying means, and a suction roll for resiliently pressing the web and felt against the surface of the drying means whereby water is removed therefrom and the web transferred to the dryin means.

16. The combination with a paper making I from the forming means to the drying means, and a suction ro11 for pressing the web and felt against the surface of the drying means whereby water is removed therefrom and the web transferred to the drying means.

17. The combination with a paper making machine from which conventional pressing means are omitted, of web forming means,

drying means, a single continuous transfer means for carrying the web from the forming means to the drying means, and suction means cooperating with the drying means for transferring the web thereto and for withdrawing water from the web and transfer means.

In testimony whereof, we have hereunto subscribed our names at Beloit, Rock County, Wisconsin.

EARL E. BERRY.

THEODORE C. ROBERTS,l

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