Method of making multilayered webs

0001The present invention describes a new type of transverse elastic, multilayer Web of material and to processes for their preparation, which is preferably as uses elastic cuffs statements in the manufacture of nappies becomes.

0002Elastic, multilayer material webs, which are produced as laminates are already known from EPA 2274754 and DE 4238541 A1. According to this Literature is an elastomeric film, for example, PE copolymer or block polymer laminated on both sides with a nonwoven web, whereby the composite is a textile appearance and textile haptic properties receives. The connection is by a lattice arranged welds which produced penetrate the whole composite, wherein the spot welds preferably have an annular shape, so that the elastic film in these Ask having holes or a very thin residual film remains, through the but gases pass liquids. Merging the tracks is the elastic film pre-stretched in the longitudinal direction and in this state, with connected to nonwoven webs, so that after unloading the film again contracts and the overlying nonwoven webs a slight wave or get crepe form, so increasing the textile impression. Appropriate Laminates can be again pulled apart to the nonwoven webs smooth receive position and counteract further routes.

0003The DE 4238541 A1 additionally provides that the nonwoven webs mechanically are stretched and decreases the elongation of the film to nonwoven web 1 to nonwoven web. 2 It is thereby achieved that during the subsequent contraction of the laminate Top and bottom work differently strongly wavy and when stretched nonwoven web 1 is slightly wavy, while nonwoven web 2 is already stretched and another Stretching prevents the web.

0004A disadvantage of these known laminates is that they manufacture one hand for their by stretching the railways increased equipment complexity and requiring the other hand, characterized in that the stretching only in the longitudinal direction is, has the finished web only longitudinally a certain elasticity and cut for the conventional use as waistband into strips, cut and transversely has to be introduced to the machine direction.

0005The own unpublished patent application DE 10304370 thus proposes, lattice-shaped weld nonwoven webs with a thermoplastic elastomer film and transverse elastic to use stretchable nonwoven webs, the plan on the carrier film rest.

0006the object, the present invention has found another way the production of a transverse elastic composite structure of film and fleece to create, z. B. be fed in the direction of production of diapers can, so that a cross-promotion as is conventionally dispensable, but also other can serve purposes such. as in the production of clothing with breathable Membranes.

0007This object is achieved with a method for producing multilayer Webs in that one with a backing layer of a elastic plastic film, and having one or two shafts arranged in this Nonwoven layers provides, being arranged the webs over a fan-shaped Finger strips of grooved rollers having supplies. The extension of Finger is focused on the grooves or the edges thereof, wherein the webs in the Grooved depressions are introduced. The track widths are gathered and so the corrugated nonwoven webs continuously on one or both sides, the plastic film and cured by pressure and temperature in the area of ​​the opposing Upper edges are welded together.

0008For this purpose, the surfaces of the webs of the first roll with engraved dots (mandrels) provided that pass through the material webs such that a contact pressure to the smooth surfaces of the webs of the second roll is reached. The elastic Film is destroyed at this point-welds to the material breathable to make, and the two fabric layers are welded together.

0009By the fan-shaped arrangement of the finger strips is a simultaneous movement the nonwoven web transversely achieved to the conveying direction, so that by a Shirring the web towards the center between each of the fingers a distance by their and the angle between them caused little slack forms, of the Cross-section of the grooves is adjusted, and enters it.

0010The result is thus a composite of one or with the use of upper and lower finger bars two shirred to fold webs on an elastic Plastic film. The used elastic film of the composite material is to stretchable nonwoven for yield strength and thus z. B. as elastic cuffs in Pant diaper or an arm - neck closure cuffs with disposable protective suits be used.

0011To prevent slipping off of the side edges of the outer fingers strips, the web can be a two-sided overhang having the width of the Traction of adjacent, sagging folds adapted.

0012The edges may be held in carriers or have piping that run in slots of own finger strips. The supernatant is after welding separated.

0013The result is a web with longitudinal shirred corrugation, the z. B. with great Advantage can be fed in the direction of production of a diaper manufacturing, where it can be fixed as cuffs or welded and cut crosswise.

0014The depressions in the roll, ie, the circumferential grooves may be rectangular, have tapered or rounded cross sections.

0015The welding is effected by means of heated "grooved rollers" (known thermoplastic bond Calendering) or by welding by means of ultrasonic technology. In ultrasonic welding, the roller is omitted with the smooth surfaces and is replaced by a corresponding ultrasound sonotrode (s. Fig. 3, 15). The lower edge of the horn is designed like a comb whose wells, the accommodation wrinkles of the fingers.

0016In addition to the two above-described welding process (thermal receipt - and ultrasonic method), the material webs are also glued.

0017In the thermal bonding process is one of the grooved rollers for a full surface replacing roll and the ultrasonic method, the horn is not a comb but smooth running. If the layers bonded to one another, it will also be a smooth roll as a counter roll used.

0018A composite material in which a gathered fabric with a non-shirred fabric is connected, can be used as loop products (Landing Zone in diapers) for Velcro can be used. By changing the depth of immersion the finger strips can be shaped to the waves that Terry can be manufactured for all usual Velcro hooks.

0019Reference to the accompanying figures, the present invention will be explained in more detail. They show:<dl tsize="7" compact="compact"><dt><b>figure 1</b></dt><dd>a plan view of the grooved roller and a finger compartments,</dd><dt><b>figure 2</b></dt><dd>the feeding of three layers,</dd><dt><b>figure 3</b></dt><dd>the use of an ultrasonic sonotrode for welding of three layers and</dd><dt><b>figure 4</b></dt><dd>a diaper cut and mounted thereon according to the invention produced cuffs.</dd></dl>

0020<b>figure 1</b> a plan view showing a roller 1 with grooves 2 and those facing a fan shape arranged mutually finger strips 3, at an acute angle dash through the grooves. 2 On the finger strips 3 is a fleece 4, on the Grooved roller 1 is conveyed. The roller 1 is driven via the shaft fifth

0021The gathering of the nonwoven webs 4 is done by two finger strips, the so are arranged such that a bar enters the groove bottom, whereby the non-woven is held down and forms a loop in that the second bar the fleece passes on the ridges of the roller to make it to the / the film / nonwoven 7 weld.

0022To a dropping of the side areas adjacent the outer finger strips 3 to prevent, has the nonwoven web 4 z. B. over-width (Figure 3) over which they can be secured. Behind the grooved roller 1, the product 14 is illustrated.

0023<b>figure 2</b> shows the device in side view, in which case a three-layer composite will be produced.

0024Here are the top and bottom corrugated webs 4 of the roller 1 and the Welding device 15 supplied that to as comb-like ultrasonic welding machine (Sonotrode) is formed. In the middle is the film web 7 of elastic Plastic delivered. Laterally outer guides 8 are indicated. The cut AB shows the resulting composite of upper and lower corrugated fleece 4 and the intervening film. 7

0025<b>figure 3</b> shows in front elevation the upper welding device as the comb-like Ultrasonic sonotrode is formed. In the present example, the finger strips rich 3 both in the base of the comb 9, and the bottom of the grooves 2 the roller 1. The nonwoven layers 4 and the film 7 are both sides about, the supernatants can be cut off.

0026<b>figure 4</b> shows sponsored by a machine diaper segment with 10 Beinausnehmungen 11th

0027In this blank 10, the composite material according to the invention in the longitudinal direction, ie tailored towards the cutting funding to cuffs 12 and are welded, whereby the cutting direction of the material web transversely to Cuff 12 occurs because the waves according to the invention 13 also along the conveyor the diaper blank lie 10th

<u>LIST OF REFERENCE NUMBERS</u>

0028<dl tsize="2" compact="compact"><dt>1</dt><dd>roller</dd><dt>2</dt><dd>groove</dd><dt>3</dt><dd>finger bars</dd><dt>4</dt><dd>fleece</dd><dt>5</dt><dd>wave</dd><dt>6</dt><dd>Stege</dd><dt>7</dt><dd>film</dd><dt>8th</dt><dd>guides</dd><dt>9</dt><dd>crest</dd><dt>10</dt><dd>diaper blank</dd><dt>11</dt><dd>Beinausnehmungen</dd><dt>12</dt><dd>cuffs</dd><dt>13</dt><dd>waves</dd><dt>14</dt><dd>product</dd></dl>