Related Application

This application claims the benefit of co- pending U.S. Pro isiona1 Patent A p1ication Seria1 No . 62/068,353, filed 24 October 2014.

Background of the Invention

The; invention disclosed herein relates to apparatus and methods for folding pieces traveling on a production line. Although the description provided relates to diaper manufacturing, the apparatus and method are easily adaptable to other applications. Although the description provided relates to forming side panels of diapers, the apparatus and methods are easily adaptable to other products, other disposable products, other diaper types and other portions of diapers .

Generally, diapers comprise an absorbent insert or patch and. a chassis, which, when the diaper is worn, supports the insert proximate a wearer's body. Additionally, diapers may include other various patches, s ch as tape tab patches, reusable fasteners and the like. The raw materials used in forming a representative insert are typically cellulose pulp, tissue paper, poly, no ove web, acquisition, and elastic, although application specific materials are sometimes utilized. Usually, most of the insert raw materials are provided in roll form, and unwound and applied in assembly line fashion.

In the creation of a diaper, multiple roll- fed web processes are typically utilized. To create an absorbent insert, the cellulose pulp is unwound from the provided raw material roll and pulverized by a pulp mill. Discrete pulp cores are formed by a core forming assembly and placed on a continuous tissue web. Optionally, super-absorbent powder may be added to the pulp core. The tissue web is wrapped around the pulp core. The; wrapped core is debulked by proceeding thro gh a. calenda u it, which at least partially compresses the core, thereby increasing its density and structural integrity. After debulking, the tissue- wrapped core is passed through a segregation or knife unit, where individual wrapped cores are cut. The cut cores are conveyed, at the proper pitch, or spacing, to a bo nda ry cora ession un it .

The diaper is built by sandwiching the formed core between a backsheet and a topsheet, and the combined web receives ears for securing the diaper about the waist of a baby.

Most products require some longitudinal folding. Folding of webs can be combined with elastic stra ds to make a cuff. Folding can be used, to ove wrap a stiff edge to soften the feel of the product. It can also be used to convert the final product into a smaller form to improve the packaging.

Diapers are typically formed in a machine di ection i a generally flat co dition. Formed diapers require folding both longitudinally to tuck the ears and associated tape or hook applicators into the ... 3 ... diaper, and also cross-folded generally at a crotch region to stack the diapers prior to packaging. Larger portio s of diapers, such as side po tio s o the front and rear panels of pane type diapers also require folding for compactness and packaging.

The folded product is then passed downstream to a packaging machine where the diapers are stacked and packaged and shipped for sale.

Suinmary of the Invention

A system for folding is provided. At least one rotary blade is passed under an intended target of the folding, and the blade folds the intended target and. passes the intended target downstream for further processing .

Importantly, the methods taught in the present application are applicable not only to diapers and the like, but in any web based operation. The folding techniques taught herein can be directed any discrete component of a manufactured article, i.e. , the methods taught herein are not product specific. For instance, the present methods can be applied as easily with respect to diaper components as they can for feminine hygiene products .

Apparatus and methods are provided for folding discrete items such as diapers at high speeds . Discrete items a e conveyed, preferably by a vacuum conveyor, in a machine direction toward a pair of rotating blades. The intended target of folding, for instance a right portion of front and back panels of a diaper, travels up a ramp, raising the level of the intended target. A rotating blade passes under the intended target of folding, and folds the ight po tion of front and back panels of a diaper over. If desired. ... 4 ... another intended target of folding, for instance a left portion of front and back panels of a diaper, travels up a second ramp, rais ng the level of the intended target, A rotating blade passes under the intended target of folding, and folds the left portion of front and back panels of a diaper ove . The folded diaper then exits the folding system and travels downstream for further processing as desired.

Brief Description of the Drawings

Fig, 1 is a top view of a rep esentative web folding system, showing a single diaper product riding on a conveyor toward a pair of folding blades;

Fig. 2 is a side view of a folding system o the present invention;

Fig, 3 is a top view of a representative web folding system, showing a single diaper p oduct riding on a conveyor toward a pair of folding blades, with a right panel portion of the diaper riding up a ramp and approaching a rotating blade;

Fig. 4 is a top view of the right panel portion of the diaper being folded by a rotating blade;

Figs. 5 a d 6 are top views of a representative web folding system, showing a folded over right panel portion, and showing a left panel portion of the diaper riding up a second ramp and approaching a second rotating blade;

Figs. 7 and 8 are top views of the left panel portion of the diaper being folded by a rotati g blade ;

Fig. 9 is top view of the folded diaper exiting the folding system and being passed downstream for further processi g;

Fig. 10 is a top view of an alternate ... 5 ... embodiment of the folding system shown in Fig. 1, the alternate embodiment including a tucker bar to maintain the first fold, and a tucker roller to maintain the first and second folds intact during downstream passage;

Fig. 11 is a side view of the folding system shown in Fig. 10;

Figs. 12a-c are top views of alternate blade config ura tions .

Description of the Preferred Embodiment

Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the i vent on, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described., the details may be changed without departing from the invention, which is defined by the claims.

It is noted. that the present folding techniques and apparatus are described herein with respect to products such as diapers, but as previously mentioned, can be applied to a wide variety of processes in which components are required to be folded. The present methods can be used to fold a portion of a web, or discrete portions, as desired. The same apparatus and techniques can be used for ears, panels, hook materials, or any other situation in which folding is desired.

Importantly, the methods taught in the present application are applicable not only to diapers and. the like, but in any web based operation. The folding techniques taught herein can be directed any component of a manufactured article desired to be folded, i.e., the methods taught herein are not product specific. For instance, the present methods can be applied as easily with respect to diaper components as they can for feminine hygiene products.

Referring now to Fig. 1, a top view of a representative web folding system is shown, A diaper product 10 riding on a conveyor 18, preferably a vacuum conveyor with vacuum commutation ports 18a, is conveyed toward a pair of folding blades 22,

Vacuum conveyor ports 18a can extend the entire length of vacuum conveyor 18, or extend for selected portions of conveyor 18, such as shown, or exte d for an e tire product le gth. In pant-type diapers, typically an absorbent core section 16 is contained in a midsection of diaper 10. Left side of panel 12 consists of both the front and rear left portions of panels of a previously formed diaper 10. Right side of panel 14 consists of both the front and rear left portions of panels of a previously formed, diaper 10. Intended fold lines L for the left panel 12 and R for the right panel 14 are acted upon by the system.

The first intended target of the folding, fold line R for the right panel 14 is seen traveling onto ramp 20, the ramp 20 comprising three sections, a conveyor level 20a, a sloped idsection 20b, and a blade clearance level 20c. Two ramps 20 are provided, one for each of the; i tended fold lines L for the left panel 12 a d R for the right panel 14.

Blade 22, with blade lobes 22a and 22b, is driven in the direction shown by rotor 24. Preferably, two independent, servo controlled blad.es 22 are programmed to aid in actively folding each part of the product 10.

Conveyor 18 travels in the machine direction at a first speed. The rotational speeds of blade 22 can match the conveyor speed (first speed) , but in some instances, the rotational speeds of blade 22 are seen to have positive effects by having a rotational speed greater than or less than the conveyor speed.

Still referring to Fig. 1, the previous description describes a horizontal conveying surface; 18 a t a fi st elevat ion ca ying at 1east a firs t ort io 14 of an article 10 to be folded. The present invention is not limited to horizontal conveying su faces 18, but also co templates vertical or sloped, conveying surfaces 18 (not shown) . When the term elevation is used in the claims, the term is not to be limited to a vertical spacing relative to the conveying surface 18, but instead should be considered a spacing in any direction away, relative to conveying surface 18, e.g., for a vertical conveyor 18, the ramp 20 would. actually elevate the first portion 14 of the article 10 in a horizontal direction relatively away from the vertical conveyor 18.

Referring now to Fig. 2, a side view of a folding system of the present invention is shown. In this view, the ramp 20 comprising three sections, the conveyor level 20a, the sloped midsection 20b, and the blade clearance level 20c can be seen. P.eferring to the first ramp in the system (upstream), right, panel 14 is shown entering onto the ramp 20 at the conveyor level 20a. As the right panel 14 travels downstream, the right panel 14 travels up ramp 20 via sloped midsection 20b, raising the level of the i tended, target, right panel 14. As the right panel travels ... g ... onto blade clearance level 20c, as shown in Fig. 3, first rotating blade 22 passes under the intended target of folding, right panel 14, and passes under blade clearance level 20c. As lobe 22a of blade 22 rotates while the right panel 14 is carried by the blade clearance level 20c, blade 22 contacts the underside of right panel 14 and folds the right panel 14 of diaper 10 over along line R, as shown in Fig. 4.

Referring now to Fig, 5, with fold line; R achie ed, the half-folded diaper 10 is passed downstream. Left panel 12 enters onto the second ramp 20 at the conveyor level 20a. As the left pane;! 12 travels downstream, the right panel 14 travels up ramp 20 via sloped midsection 20b as shown in Fig. 6, raising the level of the; intended target, left panel 12. As the left pa el travels onto bla.de clearance level 20c, second rotating blade 22 passes under the intended target of folding, left panel 12, and passes under blade clearance level 20c, As lobe; 22a of blade 22 rotates while the left panel 14 is carried by the blade clearance level 20c (Fig. 6), blade 22 contacts the underside of left panel 12 and folds the; left panel 12 of diaper 10 over along line L, as shown in Figs. 7 and 8. The diaper 10 is passed downstream as shown in Fig. 9, for further processing (e.g., folding or packagi g) as desired.

Referring now to Fig. 10, a top view of an alternate embodiment of the folding system shown in Fig. 1 is shown . In this embodiment, a. tucker bar 26 is provided at or above the blade clearance level 20c, as shown in cross section in Fig. 11. The tucker bar 26 maintains the first fold R in position while the diaper is passed downstream to the second rotating blade 22 to achieve the second fold as described previously. A tucker roller 28 is optionally provided to mai tain the irst a d second, folds R and. L intact during downstream passage.

Referring to Figs. 12a-c top views of alternate blade configurations are shown. In Fig. 12a, an oblong ear shaped blade 122 is shown. In Fig. 12b, a circular blade 222 is shown. In Fig, 12c, a bow-tie shaped blade 322 is shown. Blade shapes can be altered to improve folding per ormance. In addition, the web contacting surfaces of the blades 22, whether the web contacting surface be the top or the bottom of the blades 22, can be provided with varying coefficien t -of- friction features. For instance, one portion of the blade, 22a could be provided with increased coeff icien t-ot ^" -friction eatures relative to a second portion of the blade, 22b. Alternatively, if as in Fig. 1, upstream and downstream blades 22 are used, the upstream blade 22 could, provided with increased or decreased coefficienc-of-friction features relative to the downstream blade 22.

The; foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not. desired to limit, the invention to the exact, construction and. operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.