GB2123272A

GB2123272A - Apparatus and method for producing elasticized disposable garments

Info

Publication number: GB2123272A
Application number: GB08316854A
Authority: GB
Inventors: Hugo Lyle Kons; Richard Henry Frick
Original assignee: Kimberly Clark Corp
Current assignee: Kimberly Clark Corp
Priority date: 1982-06-21
Filing date: 1983-06-21
Publication date: 1984-02-01
Also published as: BR8303213A; IT8348520A1; GB8316854D0; IT8348520A0; GB2123272B; MX156384A; ZA833841B; AU556926B2; CA1195963A; IT1173723B; KR840005007A; AU1507583A

Abstract

An apparatus and method for elasticizing disposable garments wherein a continuously moving elastic ribbon (4) is moved into engagement with a continuously moving web (40) of material while the elastic ribbon (4) is being moved transversely of its length in an undulating pattern to produce an elasticized web 50. An oscillating means is provided which includes a rotatable roll (20) around which the ribbon (4) passes to impart oscillating movement to the ribbon just prior to its engagement with the web (40) to thereby produce an undulating pattern of the ribbon (4) on the web (40). <IMAGE>

Description

SPECIFICATION Apparatus and method for producing elasticized disposable garments 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.

Use of elastic to improve the fit of reusable garments orto 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 either 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 diap ers, methods and apparatus have been developed to apply elastic ribbon at high fabricating speeds by using an adhesive or in some other manner sealing theslastic ribbon to continuous webs which are subsequently cut into individual pieces for final use as elements of finished disposable garments. Be cause 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 shown in U.S. Patent 4,081,301 and U.S. Patent 4,227,952. In the case of U.S. Patent 4,081,301,the elastic and web substrate are con tinuously 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 approxi mately the midpoint locations of the unadhered elastic to provide separate members for use in completing a disposable diaper. The arrangement used in. U.S. Patent 4227952 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 straightened, a continuous web having straight elastic only in what will be the leg portions of a disposable diaper results.The con tinuous web may then be cut transversely midway between the ends of the elastic 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 betterfitthan 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 worn. One example of a prior art approach for applying curved elastic to a disposable garment is illustrated in U.S. Patent 3,828,367. In that patent, 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 transferred in the contoured pattern of the grooves to the roll.A problem with a grooved roll for applying elastic 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 flat tensioned ribbon, a flat ribbon is preferred in garment elsticiza tion applications. Also, a curved groove in unreliable insofar as preventing roping and C-folding of a flat ribbon is concerned.

Accordingly, a need exists for an improved method and apparatus for contouring or curving elastic ribbon while it is continuously moving at high speed and being attached to a web that is also moving at high speed. It is a further need to accomplish the aforesaid contoured attachment of the elastic ribbon in a relatively simple and accurate manner.

Viewed from one aspect the present invention provides apparatus for manufacturing elasticized disposable garments including means for continuously moving a web of material, means for attaching continuously moving elastic ribbon to the web, a roll having an axis and being rotatable about the axis, means for applying oscillatory movement to the roll, means for moving said 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 undulated due to the oscillating movement of the ribbon.

Viewed from another aspect the present invention provides a method of 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.

Thus, in a preferred embodiment, apparatus is provided for continuously moving a web of material and continuously moving thin elastic ribbon into engagement with 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 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 circumfernce of the roll to thereby impart an oscillator 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 disposable diapers, dual elasticating systems as described above may be utilized with the oscillations being such that the elastic ribbons are simultaneously moved toward each other and away from each other.

The continuous web may then be cut transversely to form separate blanks for use in fabricating a finished disposable diaper.

Some embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a simplified side elevation view partially in cross-section of one embodiment of the apparatus showing the web supply, elastic application and elsticized web take-up stations; Figure 1A is a side elevation view showing the oscillating roll in an alternate position to that shown in Figure 1; Figure 2 is a plan view of the apparatus of Figure 1; Figure 3 is a plan view of one embodiment of an elasticized web fabricated with the use of the apparatus and Figure 4 is a side elevation view of an alternative embodiment of the apparatus.

Referring generally to Figures 1 and 2, there is shown apparatus for applying a pair of elastomeric ribbons 4 along a curved line path to a web 42.

Although both of the ribbons 4 and the apparatus associated with each of them is shown in Figure 2, only one of the ribbons and its associated apparatus will be discussed herein since the ribbons and the apparatus for applying each of the ribbons are substantially identical. Referring to Figure 1, the elastomeric ribbon 4 is relatively flat, includes a wide surface 5, and has a width considerably greater than its thickness. The ribbon 4 may be 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 elas tomeric ribbon 4 may also be of a synthetic elastom er such as that with the trademark TUFTANE, a thermoplastic polyurethane manufactured and sold by the Lord Corporation.In addition to the elas tomeric ribbon 4 being supplied from a carton if it is natural rubber, the ribbon 4, either in the form of natural rubber or a synthetic elastomer, 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 purpose 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 4from 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 14. At, or just subsequent to the passing of the ribbon 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 an 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 adhesive 18 to it. The roll 14, insofar as its function relating to the application of the adhe sive 18 to the ribbon 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 wide surface 5, continues on to oscillator station 22 where it passes around oscillator roll 20. The oscillating movement of the roll 20 causes the ribbon 4 to also oscillate as the ribbon passes around the roll 20 and continues on to a 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 mechanism 26 connected to one of its ends for moving the roll 20 in an oscillating or reciprocating manner. In the embodiment of Figures 1 and 2, the oscillating motion is in a direction substantially parallel to the axial shaft 24. The oscillating mechanism may be of a type well-known in the art and consequently will not be further described herein.

The oscillating roll 20 may be disposed such that its axial shaft 24 is not in a horizontal plane and, in Figure 1A, an oscillating roll 20' is shown which is disposed substantially vertically relative to the side elevation view of Figure 1A. Note that the elements of Figure 1A are identical to those shown in Figure 1 except for items 20' and 24'. Thus, roll 20' has an axial shaft 24' and is connected to an oscillating mechanism 26 which functions to provide oscillatory movement of the roll 20' in a direction substantially perpendicular to the axial shaft 24' of the roll 20'. As may be seen in Figure 1A, the ribbon 4 rotates 900 as it approaches the roll 20 from the roll 14, passes around the roll 20' with the wide surface 5 of the ribbon 4 in contact with the roll 20' and continues on toward the chill roll 32.As in the embodiment of Figures 1 and 2, the oscillating roll 20' imparts oscillatory movement to the ribbon 4 which results in the ribbon 4 moving into engagement with a web 42 in an undulated pattern.

Referring again to Figures 1 and 2, at the web supply station 38, a continuous length of web 42 is supplied from web supply roll 40. The web 42 passes around idler roll 44 towards ribbon application stationa 30. At 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 betwen the nip formed by chill roll 32 and nip roll 48. The web 42 and elastic ribbon 4 are thereby firmly compressed together after which they continue around and leave the chill roll 32 due to the drawing force of the take-up drive rolls 28and28'.

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 while 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 48.

The engagement of the web 42 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 roll 48 permit 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.

Returning again to the passing of the ribbon 4 around the oscillating roll 20, the velocity of the chill roll 32 and nip roll 48 exceeds the velocity of the nip rolls 8 and 8' to thereby stretch the ribbon 4. The extent of the stretch may vary but, particularly for purposes of elasticizing leg areas of disposable diapers, the stretch should be about 100%. Moreover, the stretch of the ribbon 4 as it passes around the roll 20 and the friction 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 20 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 Figure 1, the composite web 42 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 28' 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 in Figure 4, those elements which function in substantially the same manner as the elements in the embodiment of the invention shown in Figure 1A carry the same identifying numerals.

The web 42 is supplied and folds 46 are formed in the web 42 by apparatus such as that disclosed in U.S. application Serial Number 340,543. In Figure 4, the web 42 is carried and continuously moved on conveyor means 60 which includes a continuous 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 Figure 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.7Q which engage the web 42 and move it downwardly between the rollers 64 and 66.

The elastomeric ribbon 4 in Figure 4 is supplied from a source and driven toward the adhesive application station 12 in a manner similar to that shown and described in Figure 1A. Just subsequent to the passing of the ribbon 4 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' does 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 the ribbon 4 is oscillated by the oscillator roll 20' and oscillating mechanism 26 in the same manner as previously described with reference to Figure 1A. The oscillat ing ribbon 4 with the adhesive 18 applied then continues from roll 20' 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 4 to the web 42. As described in detail in U.S.

application Serial Number 340,543, after application of the elastic ribbon to the web, the web is severed transversely to form individual lengths for use in completing fabrication of individual disposable diapers.

An apparatus and method for providing a dispos able garment with elastic contoured to fit the shape of 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. In the preferred embodiments, the benefit of this invention may be obtained while manufacturing such elasticized disposable garments at very high production speeds.

Claims

1. Apparatus for manufacturing elasticized disposable garments including means for continuously moving a web of material, means for attaching continuously moving elastic ribbon to the web, a roll having an axis and being rotatable about the axis, means for applying oscillatory movement to the roll, means for moving said 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. Apparatus as claimed in 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. Apparatus as claimed in 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. Apparatus as claimed in claim 1,2 or 3 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. Apparatus as claimed in any preceding claim further comprising means for applying said adhesive to the continuously moving elastic ribbon at a location at which the ribbon has substantially no oscillatory movement.

6. Apparatus as claimed in any preceding claim further comprising means for cooling the web prior to engagement of the ribbon therewith.

7. Apparatus as claimed in any of claims 1 to 5 further comprising means for cooling the ribbon and the web while they are in engagement with each other.

8. Appartus as claimed in claim 1 wherein said mearisforapplying adhesive for applying adhesiveto 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.

9. Apparatus as claimed in 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.

10. Apparatus as claimed in any preceding claim wherein the elastic ribbon has a wide surface engaging the roll.

11. Apparatus as claimed in claim 10 wherein 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.

12. Apparatus as claimed in claim 10 wherein 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.

13. A method of elasticizing disposable garments including continuously moving a web of material and a ribbon of elastic material into engage ment 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.

14. A method as claimed in 13 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.

15. A method as claimed in 13 or 14 wherein the ribbon is passed around at least a 180 portion of the circumference of the roll.

16. A method as claimed in 13, 14 or 15 wherein the direction of oscillation of the roll is parallel to its axis.

17. A method as claimed in claim 13,14 or 15 wherein the direction of oscillation of the roll is substantially perpendicular to the direction of its axis.

18. A method as claimed in any of claims 13 to 17 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.

19. A method as claimed in any of claims 13 to 18 further comprising the step of cooling the ribbon after said application of the adhesive.

20. A method as claimed in any of claims 13 to 19 further comprising the step of coolin the web.

21. A method as claimed in any of claims 13 to 20 further comprising the step of forming a plurality of folds in the web extending from a first side of the web, and wherein the oscillting 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.

22. A method as claimed in claim 13 wherein a pair of said ribbons of elastic material are moved 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.

23. A method as claimed in claim 22 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.

24. A method as claimed in claims 22 or 23 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.

25. Apparatus for manufacturing elasticized disposable garments substantially as herein before described with reference to Figures 1,2 and 3, or as modified with reference to Figures 1A or 4, of the accompanying drawings.

26. A method of elasticizing disposable garments substantially as hereinbefore described with reference to the accompanying drawings.