CA1195963A

CA1195963A - Apparatus and method for contouring elastic ribbon on disposable garments

Info

Publication number: CA1195963A
Application number: CA000428892A
Authority: CA
Inventors: Richard H. Frick; Hugo L. Kons
Original assignee: Kimberly Clark Corp
Current assignee: Kimberly Clark Worldwide Inc
Priority date: 1982-06-21
Filing date: 1983-05-25
Publication date: 1985-10-29
Also published as: GB2123272A; ZA833841B; KR840005007A; BR8303213A; MX156384A; IT1173723B; AU556926B2; AU1507583A; GB2123272B; GB8316854D0; IT8348520A0

Abstract

ABSTRACT
An apparatus and method are provided for continuously moving an elastic ribbon into engagement with a continuously moving web of material while the elastic ribbon is being moved transversely of its length in an undulating pattern to produce an elasticized web suitable for use in making garments such as disposable diapers. An oscillating means is provided which includes a rotatable roll around which the ribbon passes to impart oscillating movement to the ribbon just prior to its engagement with the web to thereby produce an undulating pattern of the ribbon on the web.

Description

FIELD OF THE INVENTION
This invention relates to a method and apparatus for applying contoured elastic ribbon to disposable garments and, in particular, to applying contoured elastic ribbon to leg areas of disposable diapers.
BACKGROUND OF THE INVENTION
Use of elastic to improve the fit of reusable garments or to provide a seal at desirable locations in reusable garments is well known. Elastic in such garments is typically sewn in or confined between garment layers in ei-ther an elongated or relaxed condition. In most cases, the elastic is affixed on an individual garment by garment basis.
In disposable garments, such as disposable diapers, methods and apparatus have been developed to apply elastic ribbon at high ~abricating speeds by adhering using an adhesive o~- in some other manner sealing the elastic ribbon to continuous webs which are subsequen-tly cut into individual pieces for final use as elements of finished disposable garments. Because of the need for high speed and the consequent complexities of applying elastic to the webs, the elastic is usually applied along a straight line.
Typical arrangements for applying elastic along a straight line to a web are those shown in Buell UO S~ Patent 4,081,301 and Sabee U~ S~ Patent 4,227,952. In the case of the Buell patent, the elastic and web substrate are continuously run at high speed while adhesive is intermittently applied to the elastic. The elastic and web are then brought together so that the elastic is adhered to the web at spaced apart locations~ The web and elastic are then cut transversely at approximately the midpoint locations of the unadhered elastic to provide separate members for use in completing a disposable diaper. The arrangement used by Sabee entails the folding of the web substrate and the continuous application of adhesive to the elastic ribbon. The web and ribbon are then brought together and adhered to each other, except at the folded portions of the web. Thus, when the elastic is cut opposite the folded portions and the web is strai~htened, a continuous w~b having straight elas~ic only in what will be the leg portions of a disposable diaper results. The continuous web then may be cut transversely midway between the ends of the elas-tic strips to form separate sections for use in fabricating finished disposable diapers.
Although elastic that is straight relative to a curved portion of the body along which the disposable garment is to fit provides a better fit than if no elastic whatsoever is used, considerably better results can be obtained if the elastic can be curved or contoured to follow the body curvature, for example, the curvature of the thigh and crotch area of an infant when the diaper is being wornO
~lthough some work has been done in this area, to the inventors' knowledge, very little of the results of this work is of any practical importance. One example of a prior ~ ~ ~f~i3 art approach for applying curved elastic to a disposable garment is illustrated ln the Bourgeois U. S. Patent 3,828,367~ In Bourgeois, a pair of elastic ribbons are fed to curved grooves in a roll under which a continuous web passes. As the roll with the ribbons in its grooves goes over the web the ribbons are ~ransferred in the contoured pattern of the grooves to the roll. A problem with a grooved roll for applying elastlc ribbon to a web is that a groove which is sufficiently deep to guide the ribbon is too deep to apply a flat elastic ribbon. Because of the better distribution of stress of a ~lat tensioned ribbon~ a flat ribbon is preferred in garment elasticization applications.
Also, a curved groove is unreliable insofar as preventing roping and C-folding of a flat ribbon is concerned~
It is a principle object of this invention to contour or curve elastic ribbon while it is continously moving at high speed and being attached to a web that is also moving at high speed. It is a further object to accomplish the aforesaid contoured attachment of the elastic ribbon in a relatively simple and accurate manner.
SUMMARY OF THE INVENTION
According to the invention f apparatus is provided for continuously moving a web of material and continuously moving thin elastic ribbon into engagement with and attaching it to the continuously moving web. The elastic ribbon is maintained under tension while being continuously fed into engagement with a roll which is rotatable about its ~3--3t~3 axis and which is provided, by oscillating means, with oscillatory movement. While the rotating roll is thus oscillating, the tensioned elastic ribbon is passed around a portion of the circumference of the roll to thereby impart an oscillatory movement to the ribbon. The oscillating ribbon is then fed into engagement with the web and assumes an undulated pattern on the web due to the oscillating movement of the ribbon. If it is desired to elasticize the leg areas of disposakle diapers, dual elasticating systems as described above may be utilized wi~h the oscillations being such that the elastic ribhons are simultaneously moved toward each other and away from each other. The continuous web may then be cut transversely to ~orm separate blanks for use in fabricating a finished disposable diaper.

BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and advantages of the invention will appear when taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a simplified side elevation view partially in cross-sectionr showing the web supply, elastic application and elasticized web takeup stations oE the apparatus of the invention;
FIG~ lA is a side elevation view showlng the oscillating roll in an alternate position to that shown in FIG. l;
FIGa 2 is a plan view of the apparatus FIGo l;

;3 ~ FIG. 3 is a plan view of the elasticized web fabricated with the use of the apparatus and method of the invention; and FIG. 4 is a side elevation view of an alternate embodiment of the inventionO
DETAILED DESCRIPTION OF THE l~lV~N'l'lON
ReferriIlg generally to ~IGS. 1 and 2~ there is shown apparatus for applying a paix of elastomeric ribbons 4 along a curved line path to a web 42~ Although both of ~he ribbons 4 and the apparatus associated with each of them is shown in FIG. 2, only one of the ribbons and its associated apparatus will be discussed herein since the ribbons and the apparatu~ for applying each of the ribbons are substantially identical. Relative to FIG. 1, ~he elastomeric ribbon 4 is relatively flatr includes a wide surface 5, and has a width considerably greater than i~s thickness. The ribbon 4 may ~e supplied in a carton 6 and, if so, it will typically be natural rubber festooned within the box in such a manner that it can be pulled, tangle free, from the carton. The elastomeric rihbon ~ may also be of a synthetic elastomer such as*"TUFTANE", a thermoplastic polyurethane manufactured and sold by the l,ord Corpora-tion. In addition to the elastomeric ribbon 4 being supplied from a c~rton if it is natural rubber, the ribbon 4, either in the form of natural xubber or a synthetic elas-tomer, may be supplied from a reel on which considerable amounts of the ribbon have been wound to permit continuous, high speed operation. Since, for the *~rade Mark 6;3 purposes of this invention, the use of a ribbon supply reel is not important, it has not been shown. The nip rolls 8 and 8' pull the ribbon 4 from the carton 6 and move it around idler roll 10 toward the adhesive application station 12. At the adhesive application station 12, the ribbon 4 passes over roll 14O At, or just subsequent to ~he passing of the ri~bon 4 over the roll 14, hot melt adhesive 18 from adhesive applicator 16 is applied to the ribbon 4. The adhesive applicator 16 is located such that the point of application of the adhesive 18 is a sufficient distance from the oscillator roll 20 such that the oscillator roll 20 does not impart lateral oscillating movement to the ribbon 4 at the point of application of adhesi~e 18 to it. The roll 14, insofar as its function relating to the application of the adhesive 18 to the rlbbon 4 is concerned, acts to maintain the ribbon 4 on a straight line path while the adhesive is being applied to the ribbon 4 by the applicator 16.
The ribbon 4, with at least one line of adhesive 18 on a wlde surface 5, continues on to oscillator station 22 where it passes around oscillator roll 20. The oscillating movement of th~ roll 20 causes the ribbon 4 to also oscillate as the ribbon passes around the roll 20 and continues on to the chill roll 32 at ribbon application station 30. The oscillator roll 20 has an axial shaft 24 about which it freely rotates as the ribbon 4 passes in engagement around it. The oscillator roll 20 also includes an oscillating or reciprocating mechanlsm 26 connected to one of its ends for moving the roll 20 in an oscillati.ng or reciprocating manner. In the embodiment of FIGS. 1 and 2, the oscillating motion is in a direction subskantially parallel to the axial sha~t 24. The oscillating mechanism may be of a ~ype well-known in the art and consequently will not be further described herein.
The o~cillating roll 20 may be disposed such that its axial shaft 24 is not in a horizontal plane and, in FIG.
lA, an oscillating roll 20' is shown which is disposed substantially vertically relative ~o the side elevation view of FIG. lA. Note that the elements of FIG. lA are identical to those shown in FIG. 1 except for those items having a ~Iprime~ designation~ The roll 20' has an axial shaft 24' and is connected to an oscillating mechanism 26 which functions to provide oscillatory movement of the roll 201 in a direction substantially perpendicular to the axial shaft 24' of the roll 20'. As may be seen in FIGo lA, the xihbon 4 rotates 90 as it approaches the roll 20' from the roll 14~ passes around the roll 20' with the wide su.rface 5 of the ribbon 4 in contact with the roll 20' and continues on toward the chill roll 32. As in the embodiment of FIGS. 1 and 2, the oscillating roll 20' imparts oscillatory movement to the ribbon 4 which results in the ribbon 4 moving into engagement with the web 42 in an undulated pattern~
Referring again to FIGS. 1 and 2, at the web supply station 38, a continuous length of web 42 is supplied ~7--i3 from web supply roll 40~ The web 42 passes around idler roll 44 ~oward ribbon application station 30. ~t station 30, the web 42 engages the chill roll 32 at point 34 and thereby becomes somewhat chilled prior to engaging the ribbon 4 at point 36. After their engagement at point 36~
the web 42 and ribbon 4 continue onward together along the surface of chill roll 32 between the nip formed by chill roll 32 and nip roll 48. The web 42 and elas~ic ribbon 4 are thereby firmly compressed together after whlch they continue around and leave the chill roll 32 due to the drawing force of the take-up drive rolls 28 and 28'.
As may be appreciated, the oscillatory motion imparted to the ribbon 4 transversely to its length by the oscillator roll 20 causes the ribbon 4 to engage the web 42 in an undulated pattern. The ribbon 4 is firmly bonded to the web 42 ~hile in the undulated pattern due to the force applied to the ribbon 4 and web 42 between the nip of chill roll 32 and nip roll 480 The engagement of the web 4~ with the chill roll 32 between points 34 and 36 along the surface of the chill roll 32 and the engagement of the ribbon 4 and the web 42 along the surface of the chill roll 32 between point 36 and the nip at nip roll 4~ pe.rmit the cooling of the adhesive 18 to thereby avoid burning of the web 42 when the ribbon 4 and thereby the hot adhesive 18 are firmly compressed against the web 42 by the nip roll 48.
Re-turning again to the passing of the ribbon 4 around the oscillating roll 20, the velocity of the chill 5~3 roll 32 and nip roll 48 exceeds the velocity of the nip rolls 8 and 8' ~o thereby stretch the ribbon 4. The extent of the stretch may vary butr particularly for purposes of elastici~ing leg areas of disposable diapers, the stretch should be about 100%. Moreoverl the stretch of the ribbon 4 as it passes around the xoll 20 and the fric-tion between the surface of the roll 20 and the ribbon 4 should be sufficient to ensure that the ribbon 4 will closely follow the oscillating movements of the roll ~0 and thereby provide the desired undulated pattern of the ribbon 4 on the web 42~ A
100~ stretch of the ribbon 4 is quite adequate in this regard.
After the web 42 with the ribbon 4 bonded to it leaves the chill roll 32~ the composite structure may pass on to the next step in the fabricating of the disposable garment or, as shown in FIG. 1, the composite web 4~ and ribbon 4 are drawn through drive rolls 28 and 28' and are wound on take-up roll 50. It may be noted that the rolls 28 and 28l are driven at a speed sufficient to maintain the desired stretch in the ribbon 4 determined by the speed of the rolls 32 and 48 relative to the speed of the rolls 8 and 8'.
With reference now to the embodiment of the invention shown i.n FXÇ. 4, those elements which function in substantially the same manner as the elements in the embodiment of the invention shown in FIG. lA carry the same identifying numeralsO The web 42 is supplied and the folds _g_ 46 are formed in the web 42 by apparatus such as that disclosed in U. S. application Serial Number 340,543, filed January 18, 1982, assigned to the same assignee as the present inventionl and incorporated herein by reference. In FIG. 4, the web 42 is carried and continuously moved on conveyor means 60 which includes a con-tinuous chain 62 and a plurality of pairs of rollers 64 and 66. As the web 42 is carried by the conveyor means 60 in the direction shown in FIG. 4, the folds 46 are formed and maintained in the web 42 between the rollers 64 and 66 by tucker means 68 having tucker bars 70 which engage the web 42 and move it downwardly between the rollers 64 and 66 relative to the view of FIG. 4.
The elastomeric ribbon 4 in FIG. 4 i5 supplied from a source and driven toward the adhesive application station 12 in a manner similar to that shown and described in FIG. lA. Just subsequent to the passing of the ribbon 4 passes around roll 14, adhesive 18 is applied to it by adhesive applicator 16 at a position such that the oscillating motion of the oscillator roll 20' do2s not appreciably move the ribbon 4 laterally of its length at the point of application of adhesive 18. Of course, if it is desired that the adhesive 18 have a somewhat undulated path on the ribbon 4, the location of the adhesive applicator 16 can be moved so that a certain amount of such adhesive undulation does occur. The ribbon 4 with the adhesive 18 applied then continues on to the oscillator station 22 where S9~3 the ribbon 4 is oscillated by the oscillator roll 20' and oscillating mechanism 26 in the same manner as previously descrihed with reference to FIG. lA. The oscillating ribbon 4 with the adhesive 18 applied then continues from roll ~0' into engagement with the web 42 where it is cooled by cooling roll 54 which also functions as a nip roll to firmly apply the ribbon 4 to the web 42. As described in detail in ~n~ n-pa~t 1,181,375, ~ Led ~an~ 22, 1~85 after applicat~ of ~e elastic ribbon to the web~ the web i5 severed transversely to form individual leng-ths for use in completing fabrication of individual disposable diapers.
An apparatus and method for ~roviding a disposable garment with elastic contoured to fit the shape o the body on which the garment is worn and thereby provide a better fit or seal of the garment against the body has been described. Moreoverp the benefit of this invention may be obtained while manufackuring sush elasticized disposable gaxments at very high production speeds.
It will be understood that the foxegoing description of the present invention is for purposes of illustration only and that the invention is susceptible to a number of modifications or changes none of which entail any departure from the spirit and scope of the present invention as defined in the hereto appended claims.

Claims

WHAT IS CLAIMED IS:

1. In an apparatus for manufacturing elasticized disposable garments including means for continuously moving a web of material and means for attaching continuously moving elastic ribbon to the web, the combination comprising:
a roll having an axis and being rotatable about the axis;
means for providing oscillatory movement to the roll;
means for moving elastic ribbon in the direction of its length around a portion of the circumference of the roll whereby the oscillating movement of the roll is imparted to the ribbon; and means for engaging the oscillating moving ribbon with the web along a path which is undulated due to the oscillating movement of the ribbon.

2. The apparatus according to claim 1 wherein:
the means for engaging the oscillating ribbon with the web comprises:
guide means for bringing the ribbon into contact with the web; and compressing means positioned downstream from the initial point of contact of the web and ribbon for pressing the ribbon and web together.

3. The apparatus according to claim 1 wherein the means for engaging the oscillating ribbon with the web comprises means positioned at the initial point of contact of the web and ribbon for pressing the ribbon and web together.

4. The apparatus according to claim 1 further comprising:
means for applying tension to the ribbon while the ribbon is moving around the roll;
the roll having a circumferential surface engaging the ribbon and having a coefficient of friction such that the friction of the roll with the ribbon and the tension in the ribbon together provide sufficient force on the ribbon to move the latter in an oscillatory manner with the oscillating motion of the roll.

5. The apparatus according to claims 1, 2, or 3 wherein the elastic ribbon has a wide surface engaging the roll.

6. The apparatus according to claim 1, further comprising means for applying adhesive to the continuously moving elastic ribbon at a location at which the ribbon has substantially no oscillatory movement.

7. The apparatus according to claim 6 further comprising means for cooling the web prior to engagement of the ribbon therewith.

8. The apparatus according to claim 6 further comprising means for cooling the ribbon and the web while they are in engagement with each other.

9. The apparatus according to claim 6 wherein said means for applying adhesive to the elastic ribbon is located, relative to the lengthwise direction of movement of the ribbon, upstream of the position of the means for providing oscillatory movement to the roll.

10. The apparatus according to claim 1 further comprising:
means for applying adhesive to the elastic ribbon; and means for maintaining the ribbon on a straight line path while adhesive is applied to the elastic ribbon.

11. The apparatus according to claim 10 further comprising means for cooling the web prior to engagement of the ribbon therewith.

12. The apparatus according to claim 1 or 10 wherein the elastic ribbon has a wide surface and the axis of the roll and the direction of oscillatory movement of the roll is perpendicular to the wide surface of the elastic ribbon during a part of the movement of the ribbon around the roll.

13. The apparatus according to claim 1 or 10 wherein the elastic ribbon has a wide surface and the axis of the roll and the direction of oscillatory movement of the roll is parallel to the wide surface of the elastic ribbon as the latter moves around the roll.

14. In a method for elasticizing disposable garments including continuously moving a web of material and a ribbon of elastic material into engagement with each other, the steps comprising:
continuously feeding elastic ribbon toward and into engagement with a rotating roll while maintaining the ribbon under tension;
oscillating the roll while passing the ribbon around the roll to impart an oscillatory movement to the ribbon; and feeding the oscillating ribbon into engagement with a web whereby the ribbon assumes an undulating pattern on the web.

15. The method of claim 14 wherein a wide surface of the ribbon is fed into engagement with the rotating roll such that the tension on the ribbon and the extent of the engagement of the ribbon surface and roll cause the ribbon to closely follow the oscillating movement of the roll.

16. The method of claims 14 and 15 wherein the ribbon is passed around at least a 180° portion of the circumference of the roll.

17. The method of claim 14 wherein the direction of oscillation of the roll is parallel to its axis.

18. The method of claims 14 or 15 wherein the direction of oscillation of the roll is substantially perpendicular to the direction of its axis.

19. The method of claim 14 further comprising the steps of:
maintaining the ribbon on a straight line path prior to its engagement with the roll; and applying adhesive to the ribbon while it is moving along said straight line path prior to engagement with the roll.

20. The method of claim 19 further comprising the step of cooling the ribbon after said application of the adhesive.

21. The method of claim 17 further comprising the step of cooling the web.

22. The method of claim 14, 15, or 19 further comprising the step of:
forming a plurality of folds in the web extending from a first side of the web; and wherein the oscillating ribbon is fed into engagement with the second side of the web opposite the first side and across the gaps in the second side created by the folds extending from the first side.

23. In a method for manufacturing elastic leg disposable diapers including continuously moving a web of material and a pair of ribbons of elastic material into engagement with the web, the steps comprising:
continuously feeding first and second elastic ribbons toward and into engagement with corresponding first and second rotating rolls while maintaining the ribbons under tension;
simultaneously oscillating the first and second rolls toward and away from each other while passing the first ribbon around the first roll and the second ribbon around the second roll to impart oscillatory movements to the ribbons in which they simultaneously move toward and away from each other; and moving the oscillating ribbons into engagement with a web whereby the ribbons assume an undulating pattern on the web in which the ribbons sequentially move toward and away from each other.

24. The method of claim 23 further comprising the step of severing the web and the ribbons transversely at each of the maximum distance locations of the first and second ribbons.

25. The method of claims 24 further comprising the step of:
prior to moving the oscillating ribbons into engagement with the web, forming a plurality of folds in the web extending from a first side of the web; and wherein the oscillating ribbons are moved into engagement with the second side of the web opposite the first side and across the gaps in the second side created by the folds extending from the first side.

26. The apparatus according to claim 4 wherein the elastic ribbon has a wide surface engaging the roll.

27. The apparatus according to claim 2, 3 or 4, further comprising means for applying adhesive to the continuously moving elastic ribbon at a location at which the ribbon has substantially no oscillatory move-ment.

28. The method of claim 15 wherein the direction of oscillation of the roll is parallel to its axis.
.

29. The method of claim 20 or 21 further compris-ing the step of:
forming a plurality of folds in the web ex-tending from a first side of the web; and wherein the oscillating ribbon is fed into engage-ment with the second side of the web opposite the first side and across the gaps in the second side created by the folds extending from the first side.