US3399884A

US3399884A - Method and apparatus for combining webs

Info

Publication number: US3399884A
Application number: US534380A
Authority: US
Inventors: Abdul S Bahrani
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 1966-03-15
Filing date: 1966-03-15
Publication date: 1968-09-03
Anticipated expiration: 1985-09-03

Description

P 1968 A. s. BAHRANI A 3,399,884

METHOD OF AND APPARATUS FOR COMBINING WEBS Filed March 15, 1966 2 Sheets-Sheet 1 INVENTOR Abdul S. Bohroni BY 47 W- AT RNEYS 2 Sheets-Sheet 2 A. S. BAHRANI METHOD OF AND APPARATUS FOR COMBINING WEBS Sept. 3, 1968 Filed March 15, 1966 INVENTOR. Abdul S. Bohroni ORNEYS m W///IIIIIIIIIIIIIIIIII United States Patent 3,399,884 METHOD AND APPARATUS FOR COMBINING WEBS Abdul S. Bahrani, Colerain Township, Hamilton County, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio, a corporation of Ohio Filed Mar. 15, 1966, Ser. No. 534,380 7 Claims. (Cl. 270-52) ABSTRACT OF THE DISCLOSURE Apparatus and method for continuously laterally shifting at least one of a plurality of side-by-side moving webs of stretchable material by passing at least one of the webs between a pair of spaced cantilevered turning bars which are positioned obliquely to the web to be shifted. The turning bars are rotated as a unit about the axis of one of the bars to cause the web to wrap around a portion of each bar, thereby shifting that web laterally and in position adjacent to the remaining webs.

This invention relates to a method of and apparatus for web handling and more particularly to a method of and apparatus for initiating and continuously effecting the combination of a plurality of moving, stretchable webs to form a multi-ply structure directly on a papermaking machine which has a winder associated therewith, without the necessity of winding a parent roll for subsequent slitting and rewinding.

In the course of the manufacture of multi-ply creped paper products in web or sheet form, the combination of the plies which comprise the multi-ply structure is usually effected on apparatus which is separate from the machine on which the creped paper itself is made. Typically, a full width web is removed from a paper machine after being wound into a large roll, usually referred to as a parent roll, which is then transferred to a combination slitter and rewinder. A pair of parent rolls is then arranged in tandem and each roll is then unwound and simultaneously severed longitudinally into a plurality of webs of the desired width which are thereafter combined to form a series of two-ply webs. It can be seen that in forming the multi-ply web in this manner, considerable time is required to transfer the parent rolls to the slitter-rewinder apparatus, to manually thread the webs through the apparatus, and to actually combine the webs into a multi-ply structure. Furthermore, the additional handling which the creped paper undergoes when combined in this manner tends to stretch the paper and remove some of the crepe since the paper is controlled by the application of tension and the commencement of each separate operation in which the paper web is handled involves the sudden application of tension, tending to stretch the paper.

It is an object of this invention to provide a method of and apparatus for initiating and continuously effecting the combination of a plurality of sections of a single, stretchable, moving web without the necessity of manually threading the sections through the apparatus effecting the combination.

It is another object of this invention to provide a method of and apparatus for the manufacture of a multi-ply web of creped paper from a single parent web, preferably directly on a papermaking machine which has a winder associated therewith, without the need for separate rewinding equipment and without removing the parent web from the papermaking machine, thereby decreasing the loss in degree of crepe which would otherwise take place.

Briefly stated, in accordance with one aspect of the present invention, a web combination method is provided which comprises the steps of slitting a single, moving,

stretchable web into a plurality of juxtaposed, narrower webs each of which has a face and reverse face similarly oriented, passing an outermost web between a pair of spaced cantilevered bars whose axes are parallel and oblique to the path of travel of the web with the web contiguous the periphery of at least one of the bars, and rotating the bars as a unit about an axis of rotation coincident with the axis of one of the bars so that the outer web portion is simultaneously caused to wrap around a portion of the periphery of each bar. After being shifted laterally, the reverse face of the outermost web is adjacent the face of the inner web, thereby forming a multi-ply web wherein the faces of each ply are in the same relative positions that they occupied prior to the combination.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter regarded as forming the present invention, it is believed the invention will be better understood from the following description taken in connection with the accompanying drawings in which:

FIGURE 1 is a fragmentary perspective view of web handling apparatus including a pair of parallel bars by means of which the present invention may be practiced;

FIGURE 2 is a fragmentary perspective view showing the web passing between the pair of parallel bars which have been rotated counterclockwise about from the position shown in FIGURE 1;

FIGURE 3 is a fragmentary perspective view showing the web and bars rotated approximately an additional 90 counterclockwise past the position of FIGURE 2 with the outermost web in superposed relationship with an inner web;

FIGURE 4 is an end view of the turning bar supporting and rotating means; and

FIGURE 5 is a fragmentary cross-sectional view of the turning bar supporting and rotating means shown taken along the line 5-5 of FIGURE 4.

Referring now to the drawings and particularly to FIG- URE 1, there is shown apparatus which can be located between the dryer of a papermaking machine and a winder associated therewith or at any point in a converting operation where a multi-ply web is to be formed from juxtaposed webs of ply material. In the embodiment shown in FIGURE 1, a web-supporting means such as roller 8 is attached to a machine frame or the like (not shown) and serves to support and guide a parent web 10 of creped paper, resinous film, or other stretchable material along its path of travel. The web 10 is fed continuously from a source which is not shown. The parent web 10 is pulled along its path of travel by a feeding means such as, for example, winder roll 9, and is severed into two narrower, juxtaposed webs 11 and 12 by a slitting means 13 supported by rigid support member 14. The narrower webs 11 and 12 may be of equal width or they may be unequal, depending upon the final web structure desired.

Support member 14 is rigidly mounted to a machine frame or the like (not shown) with slitting means 13 aligned with the direction of web travel. If it is desired to vary the respective widths of webs 11 and 12 from time to time, the mounting of the member 14 on the machine frame can be made laterally adjustable. Slitting means 13 can be a circular blade which cuts the web by squeezing it against a backup roller (not shown) positioned beneath parent web 10 and having an annular groove on its periphery corresponding to the cutting edge of slitting means 13. This type of device is well known to those skilled in the art and it is therefore not necessary to describe it further herein. When the parent web 10 is a resinous film, it may be desirable to sever it by means of a heated wire.

A support bracket 15 is bolted or otherwise affixed to a suitable support frame (not shown) and is positioned adjacent the outer edge of web 12 being oriented so that its face is in a plane substantially perpendicular to the plane defined by the moving web and forms an angle with the edge thereof. Bracket 15 serves to support the turning apparatus described below and can be made of any convenient size and thickness commensurate with its function of supporting the turning apparatus.

Rotatably mounted on bracket 15 is bar holder 16 from which spaced parallel bars 17 and .18 are cantilvered. Bar holder 16 can be a rectangular, plate-like member having a length at least equal to the spacing between the axes of

bars

17 and 18 and is preferably made from the same material as bars 17 and 18 (e.g., steel) so that the latter may be welded or otherwise rigidly attached thereto. As shown in FIGURE 5, holder 16 is carried on a shaft 19 which passes through and is journalled in bracket 15 by means of bearing 20 which may be of bronze or of other bearing metals as is well known to those skilled in the art. Although the holder and shaft are shown as an integral structure, this is not critical to the present invention and these parts could function as well if they were made from two separate pieces. As a further variant of the structure, the shaft 19 could be an extension of turning bar 17.

Mounted on shaft 19 by means of key 2.1 are ratchet wheel 22 and hand crank 23, which is used to rotate the shaft 19 and thereby bar holder 16. Outward axial movement of the crank 23 on the shaft 19 is prevented by means of cotter pin 25 or the like which is spaced from crank 23 by means of washer 24. As shown in FIGURE 4, the teeth of ratchet wheel 22 cooperate with pawl 26 to prevent counter rotation of shaft 19 and thereby maintains the shaft 19 and bar holder 16 in the desired position.

Rotation of shaft 19 can also be accomplished by using a worm and worm gear arrangement (not shown) having a gear ratio of about 40:1 or more. With this arrangement a worm gear is mounted on shaft 19 in a manner similar to the mounting of ratchet wheel 22 and the worm is then mounted at right angles to the axis of shaft 19. Counterrotation of the shaft is not a problem because a worm gear drive having a gear ratio of at least about 40:1 is not reversible since driving the worm gear will not cause rotation of the worm. The speed reduction capability of the latter arrangement is suitable for use with electric, pneumatic, or hydraulic motors which can also be employed to turn the shaft .19.

Bars

17 and 18 are cylindrical members having a highly polished outer surface to minimize the friction between the bars and the moving web and are preferably hollow to reduce the weight thereof and thereby the moment load on bar holder 16 and bearing 20. Further reduction in friction can be accomplished by providing means for supplying lubricating air between the bars and the Web as shown in U.S. Patent 1,630,713, granted May 31, 1957, to I. E. Meyer, or as disclosed in applicants co-pending application Ser. No. 508,922, filed Nov. 22, 1965, now Patent No. 3,366,298. The mounting of turning

bars

17 and 18 to bar holder 16 can be by means of a welded connection as shown in FIGURE 5, in which case the bars would not rotate with respect to bar holder 16, or they may be rotatably mounted thereto, as on bearings (not shown), to permit rotation of the bars with respect to bar holder .16. The bars are mounted perpendicularly to bar holder 16 and are therefore also oblique the web direction. A material from which

bars

17 and 18 can be made and one which has been found satisfactory for use with creped paper webs is #304 stainless steel which has been polished to give an average surface roughness of about 8 microinches. Fiberglas is also a suitable material because of its relatively high strength and light weight, the latter characteristic contributing further to the reduction of the moment load on bar holder 16 and on bearing 20.

Bars

17 and 18 are of unequal length with bar 18 being the longer of the two since it is spaced from and rotated about the axis of bar 17 and must support web 12 when the latter is adjacent web 11 as shown in FIGURE 3. The bars are disposed obliquely to the path of web travel, forming an acute angle therewith which falls within the range of from about 30 to about 60 with 45 being preferred so that the web is turned through The unsupported distal ends of the bars are spaced from the proximal ends thereof in the direction of web travel and are positioned adjacent the outer edge of web 12. Although the actual portion of the lengths of the bars .17 and 18 in contact with the web 12 are equal since the bars are parallel and the web is of uniform width, the bar holder 16 is disposed in a plane at an angle with the edge of web 12 and consequently there is a difference in the effeciive lengths of the bars, i.e. the distance from the bar holder 16 to the distal end of the web contacting portions of each. This difference is dependent upon both the spacing between the axes of the

bars

17 and 18 and the angle formed by their axes and the path of travel of web 12. In any case, unless the position of the bar holder 16 is adapted to be adjusted by movement thereof in the direction of the bar axes the spacing and angle must be such as to cause the distal end of bar 18, when rotated from the position shown in FIGURE 1 to that of FIGURE 3, to move a distance transverse the direction of movement of the webs which is at least as great as the distance which the web 12 has to be shifted. The difference in effective lengths may be expressed mathematically as follows:

AL=D cot 0 where AL is the difference between the effective lengths of the bars, D is the distance between the bar axes, and 0 is the angle defined by the bar axes and the path of travel of web 12.

Although the bars are shown to be of equal diameter, this is not essential to the practice of the present invention and it is to be understood that each of the bars can be of any convenient diameter. Similarly, the overall lengths of bars may be equal, if so desired, but the prefered configuration of the device is such that the overall length of each bar is equal to its effective length. In any event, when properly oriented the bars lie completely across web 12 whereby each completely supports web 12 when the web is shifted laterally. The preferred configuration, i.e. with the overall lengths of the bars equal to the effective lengths, results in lower bar weights, which minimizes the moment load on holder 16 and bearing 20. When equal length bars are employed, bar 17 will necessarily extend beyond the inner edge of the web 12 in order to place the distal end of bar 18 in alignment with the inner edge of web 12 at which point bar 18 is in position to clear web 11 when the bar is turned about the axis of rotation.

The web combination method of the present invention is shown in various stages of completion in FIGURES 1, 2 and 3.

In the manufacture of paper or other materials in web form the finished web is generally wound around a core which substantially corresponds in width to the web width. When a parent web is thereafter severed into two or more narrower webs and the narrower webs are combined to P form a .multi-ply web according to the method hereinafter described, as the width of the wound web diminishes because of the combination of the narrower webs, the result is that the care then has a web thereon which varies in width from a wide, single web to a progressively narrower multi-ply web. Upon completion of the combination of the narrower webs, the resulting multi-ply web is then continuously transferred to a different, narrower core to form a roll having a uniform width. This continuous web transfer is accomplished by methods and apparatus which are well-known to those skilled in the art and which will therefore not be described herein.

The combination of webs according to the present invention comprises severing a moving, parent web of stretchable material into a pair of adjacent, narrower webs 11 and 12 by slitting means 13. Narrower webs 11 and 12 each have a face and reverse face similarly oriented. It is apparent that parent web 10 may be cut into more than two webs by positioning additional slitting means 13 at spaced intervals thereacross to give the desired number and width of individual webs. After being so severed from parent web 10, outer Web 12 passes between

bars

17 and 18 which are disposed with their axes respectively overlying and underlying web 12 such that the latter is capable of passing therebetween. In this position, the outer, unsupported or distal ends of

bars

17 and 18 are adjacent the edge of web 12 which abuts web 11 and in order to form a space for the web 12 to pass between the bars, the plane define-d by the axes of the bars forms an acute angle with the web 12 so that the bars assume a position as shown generally in FIGURE 1. Bar 17, the axis of which coincides with the axis of rotation, overlies web 12 and is contiguous thereto so that the portion of web 12 upstream of the bar 17 is in the same plane as web 11 prior to the combining operation. If bar 17 were to be spaced above web 12, after the combining operation to be described is commenced the upstream portion of the web would be lifted, thereby causing a tear at a point immediately upstream of slitting means 13. To overcome this tendency when bar 17 is so spaced, it is necessary to position either a pair of guide rolls (not shown) or a guide bar (not shown) at a point intermediate slitting means 13 and bar 17 in order to prevent elevation of web 12 at the slitting means. The use of such guide rolls or guide bars is well known to those skilled in the art and will therefore not be described herein.

Bar holder 16 and bars 17 and 18 are caused to rotate as a unit about an axis of rotation coincident with the axis of bar 17. As disclosed above, the rotation of bar holder 16 can be accomplished by any convenient means such as by the hand crank shown in FIGURES 4 and 5 by an electric motor (not shown) suitably geared to the shaft to which holder 16 is attached to permit the latter to rotate with respect to support bracket 15. FIGURE 2 shows the bars rotated counterclockwise so that their axes lie in a plane substantially perpendicular to web 11. Web 12 has at this point been elevated to its maximum height above web 11 at a distance at least equal to the spacing between the bar axes plus the sum of the bar radii and has been shifted toward web 11 a distance such that a minor portion thereof overlies web 11. In FIGURE 3 the bars have been rotated approximately 90 beyond the position shown in FIGURE 2 and the web 12, which wraps each turning bar through an arc of about 180", has been shifted laterally the maximum distance and is adjacent to and completely overlies web 11. With the bars in the position shown in FIGURE 3 the reverse face of web 12 is apposed the face of web 11 in a plane parallel thereto and the webs 11 and 12 are in position to be wound together on a roll as a two-ply web. The total angular travel of the bars and holder as shown in FIG- URES 1, 2 and 3 covers about 200 of arc.

When combining stretchable webs in the manner described above, the web which is shifted will stretch somewhat in the direction of web tnavel when the bars are being turned. This is caused by having the web traverse a greater linear distance as a result of being shifted rearwardly an amount corresponding to the sum of the spacing between the bar axes and the bar radii. If the web material is elastic and the elastic limit is not exceeded, the turning of the bars will result in an increase in web tension. If the elastic limit is exceeded but the ultimate limit is not, the turning of the bars can result in a permanent elongation of the web. The rate of increase in tension in the web which has not had its elastic limit exceeded and the strain imposed on the permanently elongated web, or the change of length per unit length, will 'be dependent upon both the linear speed of the web and the rotational speed of the turning apparatus. While maintaining the speed of either of these variables constant, an increase in the speed of the other will result in a greater rate of increase in tension or a greater strain. These changes, however, only take place when the web shifting operation occurs. Upon its completion a steady-state condition is reached wherein a web which does not have its elastic limit exceeded is under increased tension while a web which has been permanently elongated continues as it did prior to the initiation of the turning operation. In the latter case only the portion of the web which passed around the turning bars while the turning apparatus was rotating has experienced stretching with the degree of stretch and the length of the web so affected dependent upon the speed of both the web and the turning apparatus.

It can be seen that although the foregoing description contemplates a bar rotation when the web is in contact with both the bars of about 200 to achieve a lateral web shift equal to the width of the shifted web, increasing the spacing between the bars or decreasing the acute angle defined by the bar axes and the direction of web travel can result in the same inward, lateral web shift while rotating the bars through a smaller angle. The maximum horizontal shift of web 12 can be expressed mathematically as follows:

H=2(D+d) cos 0 where H is the maximum distance web 12 is moved horizontally,

D is the center to center spacing of the turning bars,

d is the bar diameter, and

0 is the angle formed by the bar axes and the path of travel of the web.

In this equation it is assumed that the turning bars have the same diameter. Should the bar diameters be unequal, the term enclosed 'within parentheses on the right hand side of the equation would become where d and d represent the individual bar diameters.

It can be seen that the maximum lateral web shift for a given set of bars oriented at a given angle with the path of travel of the web occurs when the plane defined by the bar axes is parallel to the plane of web 12. Thus the equation given above is useful for initially determining the sizes and orientation of a pair of turning. bars to effect a given lateral web shift. An expression which is useful for designing the turning equipment where a two-ply web is to be formed from a pair of equal width webs relates the width of each of the webs to be combined, the angle formed by the bar axes and the direction of web travel, and the spacing between the bar axes as follows:

W sec 0 where D is the center to center spacing of the two turning bars,

W is the width of each of the individual webs which are to be combined, and

0 is the angle formed by the bar axes and the path of travel of the web.

an additional cutting means 13 such that web is severed into three webs which can then be combined into a single web by means of an additional set of turning bars of the same general configuration as described above but disposed on the opposite edge of web 10.

While particular embodiments of the invention have been illustrated and described, it will be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention and it is intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

What is claimed is:

1. Apparatus for initiating and continuously efiecting the combination of a plurality of juxtaposed, coplanar, moving, stretchable Webs into a single, multi-ply web by shifting at least one of said webs laterally, said apparatus comprising:

(a) means to feed said web along a path of travel;

(b) means to support said web along said path;

(0) at least one pair of spaced, cantilevered, parallel bars disposed obliquely with respect to the path of web travel and positioned so that one bar underlies the web to be shifted laterally and the other bar overlies it with the distal ends of said bars spaced in the direction of web travel from the proximal ends thereof;

(d) means for supporting said bars in fixed, spaced relationship to one another; and

(e) means for rotating said supporting means about an axis coincident with the axis of one of said bars, whereby the rotation of said support means causes said web to be shifted laterally.

2. The apparatus of claim 1 wherein the parallel bars are of unequal length.

3. The apparatus of claim 2 wherein the difierence in effective lengths of said parallel bars is expressed by the following relationship:

D is the distance between the bars axes, and 0 is the angle defined by the bar axes and the path of travel of the web.

4. The apparatus of claim 1 wherein the spacing between the bar axes is defined as follows:

:HL M

where D is the center to center spacing of the bars,

W is the width of each of the individual webs which are to be combined, and

5 is the angle formed by the bar axes and the path of travel of the web.

5. A method of forming a multi-ply web from a moving, single, stretchable parent web by means of a pair of spaced, cantilevered, parallel, turning bars obliquely disposed to the path of travel of said web, which method comprises:

(a) slitting said single, parent web into a plurality of narrower, juxtaposed Webs each having a face and reverse facing similarly oriented;

(b) passing an outermost of said narrower webs between said pair of turning bars with said outermost narrower web contiguous the periphery of one of said bars; and

(c) rotating said pair of parallel bars as a unit about an axis coincident with the axis of said one of said bars to cause said outermost narrower web to be first turned about a portion of the periphery of said one of said bars and thence about a portion of the periphery of the other of said bars, whereby the portion of the said other bar about which the web passes is adjacent the narrower web which is nearest the outermost web and the reverse face of said outermost web is apposed the face of said narrower web which is nearest the outermost web to form a multi-ply web wherein the faces of each ply are in the same relative position that they occupied prior to the combination.

6. The method of claim 5 wherein said parallel bars rotate through an angle of about 200 while in contact with the web and the outermost web wraps each turning bar through an arc of about 180, whereby said outermost web is shifted into a plane parallel to the narrower web which is nearest said outermost web.

7. The method of claim 5 wherein said narrower, juxtaposed webs are of equal width.

References Cited UNITED STATES PATENTS 2/1895 Daly. 6/1930 Buchanan 9333