DE10132196B4 - A method of making a product having a perforated thermoplastic structure and perforating means for carrying out the method - Google Patents

Abstract

method for producing a product with a perforated thermoplastic Structure (7) comprising at least a first (8) and a second layer (9) wherein a thermoplastic material of the first layer (8) has a lower melting point than a thermoplastic Material of the second layer (9), wherein the first (8) and the second Location (9) together over a feeder a heated perforating device (1) with a perforating calender (6) about a wrap angle of about 180 °, preferably between 190 ° and 220 °, along fed to the counter-roller (3) are in the Perforierkalander (6) surveys (5) of a Perforation roller (2) penetrate the first (8) and the second layer (9) and partially engage the counter roll (3), wherein the second Position (9) in front of the first layer (8) with the elevations (5) in contact comes and that in the area of the perforations the second layer (9) remains unmelted, and an inner surface (20) of a conical or cylindrical Form (18) forms while the first location ...

Description

The The present invention relates to a method and an apparatus for producing a product with a perforated thermoplastic Structure.

A perforated material is for example from the EP 0 472 992 B1 out. There, a nonwoven is described which has an increased surface area with an opening. The opening is created by means of a roller with a plurality of unheated pins and a roller opposite thereto with a plurality of corresponding openings. The fibers of the web next to the opening should be substantially unconsolidated. As a result, the fibers should remain mobile, so they can close the opening again with appropriate pressurization.

In GB 2 267 680 A describes an at least four-ply material, wherein two layers are designed as a meltblown fleece and two layers as support layers. The support layers may be spunbond, carded nonwoven or also meltblown web. A layer of meltblown web is perforated together with an adjacent support layer by means of a needle roller, the needles creating three-dimensional shapes. For this purpose, the needles are heated, so that the three-dimensional shape is stabilized. The layers have thermoplastic material. The location meltblown fleece and the associated support layer remain unperforated, since they are to serve as an absorber layer. The thermoplastic material of the perforated backing layer has a lower melting point than the thermoplastic material of the perforated meltblown fibers. This is intended to produce a connection between the fibers of the layers in a thermal bonding step, in particular by means of an embossing calender. The layer to be perforated of the meltblown web can be facing either the needle roller or one of the needle roller oppositely arranged counter roller during the perforation step. The meltblown web forms a surface of the wipe.

Out WO 99/65 673 A1 It is apparent that a two- or three-ply material consisting of one or two nonwoven layers and a film layer arranged on or between the nonwoven layers is hot-pressed by means of one or two embossing rollers. The film has a thermoplastic material with a lower melting point than the nonwoven fabric. When hot-pressing the film melts and thus contracts. The adjacent nonwoven bakes when pressed with the film and thereby follows the movement of the film. In this way, holes are also produced in the nonwoven fabric. The material produced is used either as a wipe in infants in the form of a three-ply material or as the topsheet of a sanitary article in the form of a two-ply material. As the film forms the surface of the topsheet of the personal care product, the nonwoven serves as a receiving and distribution layer disposed thereunder.

The It is an object of the present invention to provide a process for the production a product with a perforated thermoplastic structure to create with a three-dimensional shape that over one has certain pressure insensitivity with regard to its shape.

These Task is using a method of making a perforated Laminates with the features of claim 1 and a perforating device solved with the features of claim 5. Advantageous developments are given in the respective subclaims, wherein more Embodiments are described in the following description.

The The invention has a method for producing a product a perforated thermoplastic structure having at least one first location and with a variety of perforations on. The perforations extend through the first layer, the perforations being a three-dimensional, about conical or cylindrical Have shape. With the first layer is at least a second Location at least partially connected. The perforations extend also through the second location. The second layer forms an inner surface of the Shape, while the first layer has an outer surface of Form forms. The first layer also has a thermoplastic Material whose melting point is lower than the melting point the thermoplastic material of the second layer.

The first position is at least partially in the area of the perforations thereby melted and stabilized the shape, while the second layer in the perforation is unmelted.

The selection of different melting points of different thermoplastic materials allows to assign different properties to the respective layers. Preferably, the second La forms ge, which is unaffected by the energy input during the forming process, in a product at least partially an outer surface. The melting temperature of the second layer is chosen in particular so that surface properties remain unchanged in the second layer. This is of particular importance with regard to the use of fibers, in particular nonwoven fibers, for example in the application for hygiene products, but also in industrial products and clothing products. Thus, a hardened material is preferably present in the first layer, while the second layer is unaffected by the energy input and thus has an unchanged softness. In addition to an energy input during the forming process, it is still possible to carry out the energy input following the forming process. For example, this is possible by means of ultrasound, heat radiation or by chemical reactions. The latter takes place, for example, by applying a chemical, activating a chemical or dissolving out a chemical from the first layer, which results in at least partial hardening of the thermoplastic material of the first layer. For example, at least in the region of the perforations, a hardening agent is preferably applied directly to the first layer via a spraying device. The second layer remains essentially unaffected. An order of the agent can be made before or after the forming process.

According to one Another embodiment can also be a means between the first and the second layer can be applied. During the forming process is For example, energy is supplied to the structure, whereby the agent chemically reacts, z. As in latex, and / or physically reacted, for. B. Hotmelt. The reaction leads preferably to a curing of the agent itself, whereby the first and second layers are stabilized. Furthermore, the agent may be such that it serves as an adhesive. This will not just be around the perforation lying area, but also the remaining area of the structure stabilized.

Examples of advantageous thermoplastic material combinations can be found in the following table: Material of the second layer Material of the first layer Spunbond PP Spunbond PE Carded PP Spunbond PE Spunbond PP Spunbond BICO, z. Eg PP / PE Spunbond PP Carded BICO z. B. PP / PE preferably with PET (eg between 10% to 40%) Movie PP Movie PE Nonwoven PP Movie PE Spunbond BICO PP / PE Spunbond PE Spunbond BICO PP / PE Movie PE Nonwoven PP Highly voluminous fleece BICO PP / PE Spunbond HDPE Carded BICO, z. B. PP / PE, preferably with PET (eg between 10% to 40%) Nonwoven PP Carded PE Nonwoven PP PP nonwoven fabric with a low melting point, e.g. B. Softspun ^TM Spunbond BICO PP / PE Carded BICO PP / PE

Area weights were tested as follows: Basis weight of the second layer [gsm] Basis weight of the first layer [gsm] From about 10 to about 50 From about 10 to about 50

Preferably the first layer has a basis weight, the higher is the basis weight the second location.

Test results were as follows: method unit Pattern A Pattern B Pattern C Pattern D Pattern E grammage [g / m ² ] 30 20 + 30 20 + 30 26 + 30 27 + 30 Tear strength MD [N / 50 mm] 26.63 62.97 75.44 39.07 41.87 Breaking force CD [N / 50 mm] 23.52 24.27 29.91 17.71 10.83 Ratio of tensile strength MD / CD 1.13 2.60 2.52 2.21 3.87 Elongation at break MD [%] 21.93 23.87 27.18 17.56 18.07 Elongation at break CD [%] 30.14 39.25 41.58 78.84 75.72 Elongation at 5 N MD [%] 2.52 1.25 1.11 1.67 1.77 Elongation at 5 N CD [%] 7.83 9.03 7.20 22.54 35.28 Elongation at 10 N MD [%] 5.19 2.31 2.12 3.27 3.12 Elongation at 10 N CD [%] 12.06 14.78 12.28 38.16 62.38 bond strength [N / 25.4 mm] - 0,160 0.173 0.037 0.031 Titer 2nd position [Dtex] 2.4 2.3 2.3 2.4 4.2 Add-On Level Topsheet [%] 0.56 0.60 0.60 0.16 0.20 Strike-Through [S] 5.68 5.53 10.18 203.34 3.61 Rewet [G] 0.109 0.098 0.113 0.105 0.105 Ratio hole diameter MD / CD 1.11 1.19 1.17 1.41 1.18 hole area [mm ² ] 1.28 1.30 1.29 0.90 1.11 Open area (theoretically) [%] 19.69 19,95 19.77 13.85 17.06 Open area (measured) [%] 18.40 18.99 17.84 15.65 17.39

template A is a spunbond of PP and serves as a reference material. template B has a spunbonded fabric in the second layer and in the first layer a carded bico material on. Pattern C points in the second Location a spunbonded and in the first layer of a carded material on. Pattern D has in the second layer a BICO spunbond and in the first layer a carded bico fleece. Pattern E points in the second layer, a HDPE spunbonded web and in the first layer a carded bico material. All patterns were each bonded as a single layer before the perforation.

As in particular the comparison between the measured and the theoretical open area and preferably the ratio hole size MD / CD shows, it also succeeds, especially round openings of the perforations to stabilize. The hole diameters in MD are between 1 and 1.8 mm and in CD between 0.8 and 1.7 mm.

a has further influence on the hole sizes the speed with which the structure passes through the perforating device passes. The structure was at speeds between 5 m / s up to 130 m / s passed. As advantageous speeds have between 45 m / s and 120 m / s, in particular between 60 m / s and 95 m / s for the production a stable perforation exposed. For hole diameters, moving in a range of less than 0.5 mm is a higher operating speed adjustable. Here speeds up to 200 m / s are adjustable, preferably speeds above 150 m / s. The hole diameters are then in an area, for example between 0.5 and 0.1 mm. The perforating roller shows depending on the material preferably a temperature between about 100 ° and 160 ° C on a roll base. An oil temperature when heating is set, for example, between 135 ° C and 180 ° C, while the Counter roll preferably a temperature between 45 ° C and 95 ° C, in particular between 55 ° C and 75 ° C Has.

According to another idea, a perforating device has a feed for a structure to be perforated, which is arranged such that the structure is guided over an angle of wrap of more than 120 °, preferably over 150 °, along the counter-roller before a perforation can be carried out. This makes it possible, in particular, that warmed in a heated counter-roller, the structure of the perforation ing roller is supplied. In addition, due to the wrap, a tension in the material in contact with the backing roll is lowered. This creates a particularly stable perforation.

According to one further embodiment, the counter-roller has a coating, preferably a gum. The coating is particular between 1.5 mm and 15 mm thick, in particular at least 4 mm. The Elevations of the perforating roller can interfere with the coating. Preferably, these grip to a depth of about 2.5 to about 6 mm.

A two-layer structure to be perforated according to an embodiment in a produced integrated manufacturing process. For example in a nonwoven production a spunbonding machine with one or several bars available posed. By means of one of the bars, for example, a polymer mixture with a low melting point and by means of a second bar BICO PP / PE nonwoven produced. Furthermore, can also be on a ready-made Material applied a second layer and then perforated become. It is also possible to produce the first and the second layer inline and in one of them to perforate separate operation. As with the example of nonwoven fabric shown, there is still the possibility of combinations of To use film and nonwoven fabric. For example, a movie on a For example, carded nonwoven be extruded and then a Perforation unit are supplied.

Becomes according to a Design a nonwoven material used as the first layer succeeds it by the fact that nonwoven fibers can be partially melted and in this way stabilize the geometry of the shape. The fleece fibers can thereby, for example, at least partially lose their shape. According to one In another embodiment, the nonwoven fibers remain predominantly Part of their form and become adhesive. According to one In another embodiment, the fibers of the first layer are at least partially mixed with fibers of a web of the second layer, in particular in the form of a mesh. For example, while two are separated fabric layers made of each other between them a material limit can have have the two partially mixed together fleece layers one Material transition on. Outside the material transition the one and the other position each have only one thermoplastic Material on. Such a construction is in particular by means of a Inline method produced. Preferably, the perforated Structure a phase transition or according to one Another embodiment, for example, complete mixing the fibers at least partially in the region of the perforation. Preferably, the first and second layers become the same produced. Both layers are for example extruded nonwovens, which are manufactured on the same machine. Also exists the Possibility, different materials, each with different properties to be able to form a perforated structure. While that one fleece PP at least for the most part Part, the other fleece is for the most part made of HDPE or DAPP. About that There are also possible combinations of different production methods of nonwovens, in particular use of high volume Staple fiber webs with spunbonded nonwovens or also meltblown Nonwoven with spunbonded fabric and other combinations.

According to one Another embodiment is the first layer with a third layer connected. The third layer has a thermoplastic material on, whose melting point higher is the melting point of the thermoplastic material of the first Location. This makes it possible to produce a kind of "sandwich", with the middle Location for the stability which provides in the three layers existing three-dimensional shape.

According to one Another idea of the invention is a process for the production a perforated laminate provided, which at least having a first and a second layer. A thermoplastic Material of the first layer has a lower melting point as the thermoplastic material of the second layer. The first and the second layer are passed together in a Perforierkalander, wherein in Perforierkalander elevations of a calender roll, preferably at least needle-like projections the first and the second layer penetrate and the elevations preferably are heated, wherein the second layer before the first layer with the Surveys comes into contact.

According to one Continuing education becomes the second through contact with the surveys Location not melted while the first layer becomes at least partially sticky. According to one Another method is the second layer in an unmelted Condition passed through the calender, while however, the first layer at least partially melts. According to one However, further education can also be provided that the temperature or the energy input is so high that the thermoplastic material the first layer at least partially loses its original shape and when cooled is solidified again. With appropriate temperature setting there is still the possibility that filaments are melted in the first layer and thereby preserve their filament shape.

Further advantageous features, refinements and developments are explained in more detail with reference to the following drawings. The ones described there Features are with the above described to further embodiments combined. Show it

1 a first perforating device in which a structure to be perforated is fed directly to a perforating roller,

2 a second perforating device in which the structure to be perforated is first applied to a revolving roller,

3 . 4 a principle sequence of a perforation

1 shows a perforator 1 with a perforating roller 2 , The perforating roller 2 opposite is a counter-roller 3 arranged. In addition, there is another, third roller 4 , surveys 5 extending from the perforating roller 2 extend, reach into the counter-roller 3 as well as in the third roller 4 at least partially. The perforating roller 2 , the counter roll 3 and the third roller 4 form a perforating calender 6 , A rotational speed of the rollers is adjustable via corresponding transmission or control of electric motors. In the perforating calender 6 becomes a thermoplastic structure 7 introduced. The thermoplastic structure is a planar structure, which according to this embodiment, a first layer 8th and a second location 9 having. The first location 8th as well as the second location 9 in this case are each by a liquidator 10 the perforating calender 6 fed. Before that, however, the first location 8th and the second location 9 together via a spreading roller 11 guided. By merging both layers 8th . 9 by means of the spreading roller 11 manages both layers 8th . 9 over the entire surface without wrinkles on each other to come to rest. To the thermoplastic structure 7 to put under tension, has the perforator 1 furthermore, according to this embodiment, at least one deflection roller 12 on. As shown here, the pulley is 12 from the spreading roller 11 independently. However, it is also possible to achieve the material tension via a combination of deflection roller and expansion roller by the first layer 8th and the second location 9 over the spreading roller 11 directly into the perforating calender 6 be guided. The thermoplastic structure 7 is in the perforator 1 at least partially heated. In this case, thermal energy by means of a hot air blower 13 into the structure 7 brought in. The hot air blower 13 is in the immediate vicinity of the perforator calender 6 appropriate. Preferably, the hot air blower 13 directly to the perforation roller 2 arranged. A temperature of the hot air blower 13 emanating heated medium is adapted to the softening temperature of the thermoplastic material of the first layer. According to one embodiment, the medium is at least approximately heated to this temperature. According to a development, the medium has a temperature such that the first layer is heated to a temperature between the softening temperature of the thermoplastic material of the first layer and the softening temperature of the thermoplastic material of the second layer. Such a temperature range for the structure to be perforated is preferably also selected in other energy introduction methods. Crucial here is the temperature that perceives the thermoplastic material of the first layer. Due to energy losses, for example, when exiting the hot air blower 13 until the impact on the structure 7 and transfer of energy to the first location 8th , the medium can be adjusted to a higher temperature. The same applies, for example, when heating the surveys 5 the perforating roller 2 or in other ways of introducing energy.

In the 1 illustrated counter roll 3 preferably has openings on its surface 14 on, which is in the counter roll 3 extend. The openings 14 correspond in their dimensions in approximately the surveys 5 the perforating roller 2 , The openings 14 may be round holes, elongated holes or even channels, as for example by formation of webs on the surface of the backing roll 3 arise. Through the interaction of the perforation roller 2 with the counter roll 3 becomes the thermoplastic structure 7 perforated. The perforated thermoplastic structure 7 is along the counter roll 3 continue to the third roller 4 guided, wherein preferably the thermoplastic structure 7 is cooled. By the mesh of the counter roll 3 with the third roller 4 becomes the thermoplastic perforated structure 7 on the third roller 4 filed from there to a pulley 12 out of which the perforated thermoplastic structure 7 in turn to a spreading roller 11 arrives. From the spreading roller 11 enters the thermoplastic structure 7 to a rewinder 15 , A winding up of the perforated structure 7 takes place under a certain tension, via the pulley 12 as well as the spreading roller 11 is adjustable. In particular, the voltage is adjusted as a function of the speed with which the structure 7 to the rewinder 15 arrives. The spreading roller 11 ensures that wrinkling does not occur during winding. At the same time, the tension is adjusted so as not to pull apart and thereby destroy the three-dimensional shape. The on This three-dimensional shape produced in this way can be wound up with higher tensions than a thermoplastic structure 7 that is not merged.

How out 1 shows, prefabricated layers are brought together and then wound up. The connection of the first and the second layer achieved by the perforation is sufficient to remove the material by means of the rewinder 15 to store for further processing, without the risk that both layers 8th . 9 to separate again. According to a development not shown here, however, it is possible to use a structure that is at least partially connected to each other before and / or after the perforation in the usual manner known in the art.

2 shows one too 1 similar second perforating device 16 which in turn has a perforating calender 6 having. Again, this is by unwinders 10 a thermoplastic structure 7 perforated and by means of a rewinder 15 rolled up. Unlike the first perforator 1 becomes at the second perforator 16 however, the first location 8th and the second location 9 first on the counter-roller 3 guided, there by means of the hot air blower 13 heated and then to the perforating roller 2 guided. One in the thermoplastic structure 7 To be set material tension is thus on the rotational speed of the backing roll 3 and the respective Abwicklergeschwindigkeit for the first and second layer 8th . 9 regulated. The application to the counter roll 3 allows that to continue in the first location 8th energy to be introduced via the second layer 9 can be introduced without the first layer 9 must contact the medium directly. Furthermore, the Perforierungskalander 6 one of the perforating roller 2 downstream pulley 17 on. The pulley 17 is preferably arranged so that the perforated structure 7 under tension from the perforating roller 2 as well as the third roller 4 is first led away before the structure 7 back to the third roller 4 is supplied. The pulley 17 is particularly advantageous for material widths of> 500 mm. Here, the Perforierungskalander 6 be supplemented by a spreading roller, both of which are not shown here.

In the 1 as 2 illustrated perforating devices 1 . 2 have 3 rollers that the perforator calender 6 form. The arrangement of the rollers to each other is as shown so that their roller centers are arranged approximately on a straight line. However, the rollers can also be arranged offset from each other, that is, at an angle between preferably 160 ° and 40 °. The perforators 1 . 2 may further comprise additional devices such as sprayers, ultrasonic devices, measuring devices.

3 and 4 show the process of perforation of a thermoplastic structure 7 with a first location 8th and a second location 9 in a schematic view. While the first location 8th at least partially melted in the region of the perforation, preferably at least partially completely melted, preserves the second layer 9 their shape. This achieves a stabilization of a three-dimensional shape formed by perforation 18 , where the first location 8th an outer surface 20 the shape 18 forms while the second layer 9 an inner surface 21 the shape 18 forms.

Examples for one Application of the laminate or the structure in a product are sanitary articles, sanitary and household articles, especially wipes, medical products, surface applications at Products, filter materials, protective clothing, geotextiles, Disposable products.

Claims (6)

Process for producing a product with a perforated thermoplastic structure ( 7 ), which at least a first ( 8th ) and a second layer ( 9 ), wherein a thermoplastic material of the first layer ( 8th ) has a lower melting point than a thermoplastic material of the second layer ( 9 ), the first ( 8th ) and the second layer ( 9 ) together via a feed of a heated perforating device ( 1 ) with a perforating calender ( 6 ) over a wrap angle of over 180 °, preferably between 190 ° and 220 °, along the counter roll ( 3 ), wherein in the perforating calender ( 6 ) Surveys ( 5 ) from a perforating roller ( 2 ) the first ( 8th ) and the second layer ( 9 ) penetrate and partially into the counter-roller ( 3 ), the second layer ( 9 ) before the first situation ( 8th ) with the surveys ( 5 ) and that in the area of the perforations the second layer ( 9 ) remains unmelted, and an inner surface ( 20 ) of a conical or cylindrical shape ( 18 ), while the first layer ( 8th ) but at least partially melts and an outer surface ( 21 ) of the figure ( 18 ) forms and the shape ( 18 ) stabilized. Method according to claim 1, characterized in that the first layer ( 8th ) is a fleece, the filaments are melted while preserving their filament shape. Method according to one of claims 1 or 2, characterized in that the elevations ( 5 ) are heated. Method according to one of claims 1 to 3, characterized in that the first layer ( 8th ) at least up to the softening temperature of the thermoplastic material of the second layer ( 9 ) is heated. Heated perforating device ( 1 ; 16 ) with a perforating calender ( 6 ) for carrying out the method according to claim 1 with a perforating roller ( 2 ), the surveys ( 5 ) and a mating roll ( 3 ) into which the surveys ( 5 ) at least partially engage, characterized in that a third roller ( 4 ) in which the surveys ( 5 ) of the perforating roller ( 2 ) at least partially engage and a feed for a structure to be perforated is arranged so that the structure ( 7 ) over a wrap angle of over 180 °, preferably between 190 ° and 220 ° along the counter roll ( 3 ) is performed before a perforation is feasible. Perforation device ( 1 ; 16 ) according to claim 5, characterized in that the counter-roller has a temperature which is at least about 30 ° C lower than a temperature of the perforating roller.