CA1114411A - Method and apparatus for folding web material - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A method and apparatus for folding web material to produce packages of a converted product wherein a multiple width roll is unwound and slit to produce a plurality of webs, each web thereafter may be first longitudinally folded and thereafter C-folded, the webs thereafter being superposed and transversely pinch cut to produce substacks, the substacks being accumulated into a final stack for each package of the converted product.

Description

BACKGROUND AND SUMMARY OF INVE~TION:
.--This invention relates to a method and apparatus for folding web material and, more particularly, to a method and apparatus which is especially su:lted for web material derived from a parent roll which is slit and thereafter longitudinally folded. Exemplary of the webs suitable for use in the practice of the invention are paper towels.

The paper towels with which the instant invention are concerned normally are derived from base paper which has a ream weigh~ of about 7 to about 50 pounds per 3,000 ~quare 10 feet. More particularly, the stock currently employed commercially in the United States today has a 30pound per ream basis weight and ~s normally embossed to increase absorbency and softness.

The converting machinery employed to make the C-folded towels normally provides an initial "V" longitudinal fold. For exEmple, the industrial type C-folded towel starts rom a web 13-14" wide, folded in half and then C-folded inwardly on both longitudinal edges to a new total width of approximately 3-1/4". The machinery for producing such towe~s normally is limi~ed to a four-wide parent roll, viz., of the order 20 of 50-65". The parent roll is slit into four discrete webs which are ~hen V and C folded after which they are each transversely slit by pinch cutting rolls and then transferred individually by vacuum drums to individual chutes -- one for each web. The chutes are conveniently provided on a conveyor and remain in a temporary position l~til a predetermined number of web segments, are accumulated. Normally, 150-300 towels (web segments) are 28 provided for each package.

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A number of problems ~nd limitations character-lze the prior art method and apparatus. In particular, there was a distinct size limitation because ~he vacuu~ rolls or drums were limited for all practical purposes to a four-wide machine. For example, if a ~acuum was drawn from one end of the roll the vacuum conduits leading to the ~ppos:ite side of the roll contained more air. And since imposit~on of the vacuum was provided intermittently, each vacuum draw was first required to exhaust a certain quan~ity of air and, for ~he ports more remote ~rom 10 the point of vacuum draw, there was a time lag in response or a sluggish vacuu~ response whlch urther limited the speed of operatio o~ the mach~ne. Additionally, the stacks of towels were each accumulated from a precise transverse location in the web so that if the parent paper machine had a caliper variation, one stack o towels would be continually under or over caliper depending upon the charac~eristic of the parent producing machine.

Another prior art method and apparatus which has been employed for a converted product such as C-folded facial 20 tissues is a continuous stack producer wherein a large plurality ; of parent rolls are pro~ided so that 200 to 300 longitudinally folded superposed webs can be accumulated and then simultaneously cut transversely -- as by the apparatus seen in~3,288,009. Such apparatus did not recommend itself for toweling because of the inability to emboss individual slit webs, the space requirements being enormous and not suited for towel production, and the machinery itself presented substantial operational difficultiPs when employed for anything but facial tissue.

Although, in a sense, the instant invention seemingly 30makes use of elements and techniques present i~ part in each of the foregoing prior art machines, it is believed that the _ 3 f~

limitations characteristic of these prior art machines contra-indicated the usage of various parts in a new combin~tion.
According to the invention, a multipl.e width roll of web material ~ a.l be.
is slit to provide a plurality of webs, each web b~ longi-tudinally folded in V and C fashion. Thereafter the webs are superposed and transversely pinch cut to provide substacks after which a plurality of substacks are accumulated ~o provide a final stack of the converted product.

DETAILED DESCRIPTION:
.

The invention is described in conj~nction with an illustrative embodiment in the accompanying drawing, in which -- , FIG. 1 is a plan view of apparatus incorporating teachings of the invention;

FIG. 2 is a fragmentary perspective view of a por~ion of the apparatus o FIG. l;

FIG. 3 is a sectional:view through one V-folded web as seen along the line 3-3 applied to FIG. 2;

FIG. 4 is a sectional view taken along the line 4-4 20 Of FIG. 2;

FIG. 5 is a side elevational view of the apparatus of FIG. 1 such as would be seen along the sigh~ line .
5-5 applied to FIG. l;

FIG. 6 is another elevational view of the apparatus ~-of FIG. 1 such as would be seen along the sight line 6-6 26 of FIG. l; and _ 4 _ ,, .. ~ . . .
. .

. FIG. 7 is yet anoth~r elevational view, thi~ bein~
taken along the sight line 7-7 ~s applied to FIG. 1.

Referring first to FIG. 2, the numeral 10 desi~nates generally a parent roll which ~s seen to provide a sPrie~ of slit webs 11 which are V-folded (FI~. 3) and C-folded (FIG. 4) as at 12 and 13, respecti~ely and then passed into feed belts 14 for transverse cutting as at 15.

The eleva~ional view in FIG. 5 shows the opera~ion ~ust referred to and in addition, after ~he cutoff mechani6m 15 shows a take-away mechanism 16 (consisting of a pair of lO spaced belts) and an orbital packer 17. The orbital packer 17 assists in the development of a stack of towels or the like which then is packaged.

Still referring to FIG. 5, it is seen that in the illustration given there are provided five V-folding plates 12'~
Thus, the web from the parent roll is slit into ive discre~e webs for passage over the five V-folding pla~es 12'. Here, is should be appreciated that the roll widths may vary, as well as the machine arrangement. For example, two multi-width parent rolls may be mounted in axial alignment as compared with one wider : 20roll.

As each web issues from its associated ~-folding pla~e 12', it passes between a pair of creasing rolls 18 and through a C-folding plate 13 ' . Downstream of each C-folding plate 13' .
.and further compressing rolls l9. The thus folded webs are conveyed : :
on carrier belts 20 into the feed belt unit 14 and thence to the cutoff roll lS. Thus, the cutoff roll simultaneously pinches .
through five Ior six or more) longitudinally folded webs to provlde a substack of that number. If the ultimate package is to contain 150 towels, 30 substacks are accumulated in the orbital packer ^~prior to shifting of the stack into the p~ckagin~ mechanlsm.
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OPERATION:

The overall operation of the me~hod and appar~tus of the invention can be first appreciated from a comparison of FIGS. 1, 2 and 6. There the ~umeral 10 designates a parent roll mounted on a suitable unwind stand schematically represented at 21 and which is unwound by a belt arrangement 22 to provide a web 23. The web 23 is passed around various idler rolls (un-numbered) and a dancer roll 24 into an embosser generally designated 25. Thereafter, the web passes through a sli~ter 26, over z turning roll 27 into the V-folding plates 12' and ~he C-folding plates 10 13'. As can be readily appre~iated from the top left hand portion of FIG. 1, the various slit web portions 11 are superposed and conducted by the belt unit 14 in~o the cuto~f roll unit 15.

The orbital packer 17 is reciprocated ver~ically by means of an eecentric mechanism depicted schematically at 17' in FIG. 2. The packer 17 terminates in a pla~e or tamper at the bottom thereof to push ~he five web segments (as illustrated in a substack S') onto a previously developed subs~ack S -- see FIG. 2 -- which in turn is supported on a set of count separating :` fingers 28. More particularly, the fingers 28 are mounted for 20 selective pivotal motion into t~e subs~ack path about an axis 29. The packer 17 simply displaces the sub-stack S, S', etc.
vertically a small amou~ , the lowest sub-stack S' being placed on the two opposing sets (re~r set not shown) of inserted count sep-arating fingers whlch descend through the position T (representing a ~-complete stack) and place a completed stack U onto a bottom dead platP
(now shown) for horizontal movement as at 30 into the con~eyor :~
bucket 31, viz., in the position occupied by ~he stack V. Thus, a considerably greater peed can be developed -- for example, 29 with a count of 150, 30 orbits of the packer wouid represent a .

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c~mpleted s~ack whereas, according to the prior art method, 150 orbits of the packer would be required to develop a complPted stack.

The conveyor buckets or chutes 31 are carried by an index conveyor generally designated 32 and which is suitably integrated with the frame F (see FIG. 1) or other structur~ which carries the already mentioned par~s.

After the stack V is placed on the index conveyor 32, it is transferred laterally by means of a pusher 33 (see FIGS. l and 5) if it is acceptable, i.e., up to specification. Unacceptable stacks are continued on the index conveyor 32 to a re;ect s~ation at the end of travel at 34. The suitable stacks are conveyed on a conveyor 35 (see also FIG. 7) where they are sub~ected to a banding operation via a banding mechanism 36~ The mechan-ism 36 deri~es a banding st~ip for each stack V fr~m a parent roll 37.
After banding the stacks are conveyed by compression belts 38 and 39 to a discharge poin~ 40 for cartoning.

From the foregoing, it will be seen ~hat not only have the draw~acks of prior art manufacture been avoided but further this has been done in an arrangement which is especially space efficient. As can be appreciated from ~IG. 1, the steps of unreeling, embossing, slitting and V folding are perfor~ed when the web (or webs) is tra~eling in a first direction, i.e., along a first path. Then, the steps of C folding, accumulating and transverse severing are all performed along a second path at a right angle to the first path. The packing or tampering occurs in a vertical path of slight dis~ance, i.e., essentially a step in the second path after which stack pushing occurs as at 30 also in line with ~he second path. Lastly, the stacks are conveyed along a third path parallel to the first path by the con~eyor 32.
The "good", i.e., acceptable stacks are shlfted laterally fo~
.

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movement in a fourth path parallel to the first and third paths while the "rejects" continue in the thlrd path. This makes for a most compact equipment arrangement as well as one wherein the web segments are under positive control at all ~imes so as to achieve high speed, reliable operation.

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Claims (2)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN
EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED
AS FOLLOWS:

1. A method for producing packages of converted product wherein a multiple width roll of web material is unwound to produce a continuoue web and thereafter slit and folded longitudinally to produce a plurality of narrower webs comprising horizontally superimposing said plurality of narrower webs, advancing said superposed plurality of narrower webs along a single horizontal path, transversely pinch cutting the superposed narrower webs at equally spaced intervals to produce substacks, advancing said substacks along said path between horizontally spaced apart upper and lower conveying means, and sequentially vertically tamping said substacks from their confinement between said spaced apart conveying means on finger supports to accumulate said substacks into a stack.

2. The method of claim 1 in which said multiple width roll has a basis weight of about 7 to about 50 pounds per 3,000 square feet ream to provide a relatively flexible lightweight web material suitable for toweling.