Unit for laterally stretched elastic membrane

Abstract

A stretching unit (10) for laterally stretching elastic membranes (84, 86) includes a first stretching device (12) and a second stretching device (14), each having a corresponding clamping area (68) and a corresponding release area (70), wherein the release areas (70) of the first stretching device (12) and the second stretching device (14) are aligned with each other along a common lateral release line (72).

Description

Technical Field

[0001] This invention relates to the production of elastic laminates.

[0002] This invention has been developed, particularly relating to the production of elastic laminates intended for use in the manufacture of hygiene products, such as absorbent hygiene products, elastic bands for dressings, etc.

[0003] More specifically, the present invention relates to a unit for laterally stretching at least one elastic membrane sandwiched between two nonwoven webs. Background Technology

[0004] In order to produce hygiene products, such as diapers and other absorbent products, components with different properties are assembled together, such as absorbent core, bottom sheet, top sheet, elastic waistband, elastic side sheet, closure structure, and elastic barrier for the legs (leg brace), etc.

[0005] Some components of absorbent sanitary products, such as elastic bands for the legs, elastic leg barriers, elastic side panels, and elastic waistbands, are made of elastic laminates.

[0006] Depending on the properties of absorbent hygiene products, elastic laminates can be manufactured in various ways. For example, some types of elastic laminates can be formed from one or more nonwoven webs bonded to an elastic membrane. In some applications, the elastic membrane is stretched in the transverse direction before being fixed between two opposing nonwoven webs.

[0007] EP3496687 A1 describes a method and apparatus for assembling resilient laminates, wherein a first nonwoven web is wound around the outer cylindrical surface of an anvil rotating about a rotation axis, a first elastic membrane and a second elastic membrane are stretched in a transverse direction on a first stretching device and a second stretching device, and are applied to the first nonwoven web on an anvil in a first application area and a second application area, the first application area and the second application area being axially and angularly moved relative to the rotation axis, a second nonwoven web is fed to an anvil above the first elastic membrane and the second elastic membrane stretched in the transverse direction, and the first nonwoven web and the second nonwoven web are ultrasonically welded together by the first elastic membrane and the second elastic membrane, and are contained in a central portion between the first elastic membrane and the second elastic membrane.

[0008] Other similar solutions are disclosed in EP3496688, EP3496689, and EP3496690.

[0009] In the solution described in EP3496687 A1, a first and a second elastic membrane, stretched in the transverse direction, are applied to the nonwoven web in two regions offset at an angle to each other. This results in difficulties in positioning the elastic membranes relative to the nonwoven web and raises the issue of ensuring precise spacing between the two elastic membranes. Furthermore, arranging two stretching units in two different regions involves large production lines, which may be incompatible with the dimensions of the manufacturing plant.

[0010] Existing tensioning devices are generally interpreted as such as those in EP2260813 B1. Figure 2 As shown, a pair of tension members rotating about respective axes of rotation that are inclined relative to each other are driven by corresponding motors that protrude on opposite sides relative to a central plane extending between the two tension members. This arrangement requires the operator to perform setup and adjustment operations on both sides of the unit. These operations are often interrelated, and therefore typically require setup or adjustment on one side after setup or adjustment on the other side of the unit.

[0011] Another problem with existing equipment used for producing elastic laminates is its poor flexibility. Currently existing stretching units form a single type of elastic laminate. If a manufacturer aims to expand its product range, it should typically install a separate production line for each type of product intended for commercialization. Summary of the Invention

[0012] The present invention aims to provide a stretching unit that overcomes the problems of the prior art.

[0013] According to the present invention, this objective is achieved by the stretching unit according to claim 1.

[0014] The optional features of the present invention constitute the subject matter of the dependent claims.

[0015] The claims are an integral part of the disclosure relating to this invention. Attached Figure Description

[0016] The invention will now be described in detail with reference to the accompanying drawings, which are given by way of non-limiting example only, in which:

[0017] Figure 1 This is a schematic perspective view of the stretch unit.

[0018] Figure 2 This is a partial cross-sectional perspective view of the tension unit of claim 1.

[0019] Figure 3 It is along Figure 1 The cross-sectional view taken from line III-III.

[0020] Figure 4This is a schematic diagram of a first embodiment of equipment for producing elastic laminates.

[0021] Figure 5 It is shown Figure 4 A schematic plan view of the operation of the equipment.

[0022] Figure 6 This is a schematic diagram of a second embodiment of equipment for producing elastic laminates, and

[0023] Figure 7 , Figure 8 , Figure 9 , Figure 10 These are schematic cross-sectional views of different embodiments of resilient laminates, which can be produced using the equipment and methods disclosed herein.

[0024] It should be understood that some components may not be shown in the accompanying drawings to simplify the understanding of the drawings, and the various drawings may not be shown at the same scale. Detailed Implementation

[0025] Reference Figure 1-3 The number 10 indicates a stretching unit, used to stretch a continuous elastic membrane in a direction transverse to the longitudinal direction of the elastic membrane.

[0026] The stretching unit 10 includes a first stretching device 12 and a second stretching device 14. The first stretching device 12 and the second stretching device 14 are substantially the same as each other.

[0027] Each of the first tensioning device 12 and the second tensioning device 14 includes a first tensioning member 16 and a second tensioning member 18, which are about respective first rotation axes 20 and second rotation axes 22 that are inclined relative to each other. Figure 3 Rotate.

[0028] As shown in the figure, the first tension member 16 and the second tension member 18 can be disc-shaped. In a possible embodiment, the first tension member 16 and the second tension member 18 can have shapes different from those of a disc.

[0029] The first tension member 16 and the second tension member 18 have corresponding outer edges 24, 26, which are provided with clamping elements for clamping corresponding side edges of the elastic membrane. The clamping elements may be suction holes 28 that are open on the outer edges 24, 26 and connected to a subatmospheric pressure source, as will be disclosed below. The outer edges 24, 26 of the tension members 16, 18 may be provided with protruding pins that engage with the side edges of the elastic membrane, or alternatively or additionally, engage with the suction holes 28.

[0030] Reference Figure 1-3Each of the first tensioning device 12 and the second tensioning device 14 includes a corresponding drive assembly 30 configured to drive the corresponding first tensioning member 16 and the second tensioning member 18 to rotate about the corresponding rotation axes 20 and 22.

[0031] The drive assembly 30 of each of the first tensioning device 12 and the second tensioning device 14 is arranged on only one side relative to the corresponding tensioning member 16, 18. More specifically, the first tensioning member 16 and the second tensioning member 18 of each of the first tensioning device 12 and the second tensioning device 14 are located on the distal and proximal sides of the corresponding drive assembly 30, respectively, and the drive assembly 30 extends on only one side relative to the first tensioning member 16.

[0032] In the embodiment shown in the accompanying drawings, the drive assembly 34 of each of the first tensioning device 12 and the second tensioning device 14 includes a first motor 32 and a second motor 34 that respectively drive the first tensioning member 16 and the second tensioning member 18. Each motor 32, 34 may include a corresponding reduction gear. In each of the first tensioning device 12 and the second tensioning device 14, the two motors 32, 34 are arranged on only one side relative to the corresponding tensioning member 16, 18.

[0033] In a possible embodiment, the drive assembly 30 of each of the first tensioning device 12 and the second tensioning device 14 may include a single motor and a connector assembly connecting the single motor to the respective first tensioning member 16 and the second tensioning member 18. In this embodiment, in each of the first tensioning device 12 and the second tensioning device 14, the single motor and the connector assembly are arranged on only one side relative to the respective tensioning members 16, 18.

[0034] The first motor 32 may be coaxial with the corresponding first tension member 16 and may be connected to it via the first shaft 36. The second motor 34 may be eccentric to the corresponding second tension member 18 and may be connected to the second tension member via the second shaft 38 to a belt drive including a toothed belt 40 and a pair of toothed pulleys.

[0035] Reference Figure 1-3Each of the first tension member 16 and the second tension member 18 has a suction port 28 communicating with a plurality of connection holes 42 opening on the side surface of the respective first tension member 16 and the second tension member 18 facing the drive assembly 30. The connection holes 42 of each of the first tension member 16 and the second tension member 18 are pneumatically connected to corresponding fixed suction chambers 44, 46, which have an open side facing the side surface of the respective first tension member 16 and the second tension member 18, on which the connection holes 42 open. The suction chambers 44, 46 are connected to a subatmospheric pressure source via corresponding tubular elements 48, 50 and a flexible tube (not shown). The suction chambers 44, 46 of each of the first tension device 12 and the second tension device 14 are arranged on the side of the respective tension member 16, 18 facing the respective drive assembly 30.

[0036] In a possible embodiment, the fixed suction chambers 44, 46 of each of the first stretching device 12 and the second stretching device 14 are coaxial with the corresponding first stretching member 16 and second stretching member 18.

[0037] In one possible embodiment, the suction chamber 44 of the first tensioning device 16 and the second tensioning device 18, which are connected to the tensioning member 16 located on the distal side of the respective drive assembly 30, can be selectively connected and disconnected from the sub-atmospheric pressure source, such that the tensioning unit 10 can be operated only by the external tensioning member 18, while the internal tensioning member 16 is not in operation.

[0038] Reference Figure 1-3 Each of the first tensioning device 12 and the second tensioning device 14 includes a first adjustment mechanism 52 and a second adjustment mechanism 54, respectively associated with the first tensioning member 16 and the second tensioning member 18.

[0039] Each of the first adjustment mechanism 52 and the second adjustment mechanism 54 is configured to adjust the tilt angle of the rotation axes 20, 22 of the respective first tension member 16 and second tension member 18.

[0040] The first adjustment mechanism 52 and the second adjustment mechanism 54 of each of the first tensioning device 12 and the second tensioning device 14 are arranged on the side of the corresponding first tensioning member 16 and the second tensioning member 18 facing the corresponding drive assembly 30.

[0041] refer to Figure 1 and Figure 2Each of the first adjustment mechanism 52 and the second adjustment mechanism 54 includes a base 56 and an adjustable support structure 58. The angular position of the adjustable support structure 58 relative to the base 56 can be adjusted about a corresponding adjustment axis 60. The angular movement of the adjustable support structure 58 about the adjustment axis 60 can be controlled by a manual actuator 62 or a motor (not shown).

[0042] Each adjustable support structure 58 rotatably supports a corresponding first axis 36 or second axis 38. Therefore, adjusting the angle of the adjustable support structure 58 about the adjustment axis 60 changes the inclination of the corresponding first rotation axis 20 or second rotation axis 22.

[0043] The fixed suction chambers 44, 46 of each of the first stretching device 12 and the second stretching device 14 are supported by the adjustable support structures 58 of the corresponding first adjusting mechanism 52 and second adjusting mechanism 54. Therefore, when the inclination of the rotation axes 20, 22 of the first stretching member 16 and the second stretching member 18 is adjusted, the relative positions between the first stretching member 16 and the second stretching member 18 and the corresponding fixed suction chambers 44, 46 will not change.

[0044] The base 56 of each of the first adjustment mechanism 52 and the second adjustment mechanism 54 may include a corresponding guide 64 that allows adjustment of the position of the respective first adjustment mechanism 52 and the second adjustment mechanism 54 in the lateral direction Y.

[0045] Each of the first adjustment mechanism 52 and the second adjustment mechanism 54 may include an auxiliary adjustment device 66 that allows adjustment of the position of the corresponding first tension member 16 and the second tension member 18 along a linear direction X and / or Z orthogonal to the lateral direction Y. The auxiliary adjustment device 66 may be manually controlled or controlled by a corresponding motor (not shown).

[0046] refer to Figure 3 Each of the first stretching device 12 and the second stretching device 14 has a corresponding clamping area 68 and a corresponding release area 70.

[0047] The first tensioning member 16 and the second tensioning member 18 of each of the first tensioning device 12 and the second tensioning device 14 are spaced apart from each other by a first distance W1 in the lateral direction Y in the clamping region 68, and are spaced apart from each other by a second distance W2 greater than the first distance W1 in the release region 70. The distances W1 and W2 of the first tensioning device 12 and the second tensioning device 14 may be equal or different.

[0048] Specific reference Figure 2 and Figure 3The release areas 70 of the first tensioning device 12 and the second tensioning device 14 are aligned with each other along a common transverse release line 72.

[0049] Reference Figure 3 The first tensioning device 12 and the second tensioning device 14 are disposed on opposite sides of the central plane 74 orthogonal to the common transverse release line 74. The two first tensioning members 16 of the first tensioning device 12 and the second tensioning device 14 are located on opposite sides of the central plane 74, which are located on the far side of the respective drive assembly 30.

[0050] In each of the first stretching device 12 and the second stretching device 14, the corresponding drive assembly 30, fixed suction chambers 44, 46, and adjusting mechanisms 52, 54 extend only on one side of the central plane 74. The drive assembly 30, fixed suction chambers 44, 46, and adjusting mechanisms 52, 54 of the first stretching device 12 and the second stretching device 14 extend on opposite sides of the central plane 74.

[0051] refer to Figure 4 The equipment used to produce elastic laminates is indicated by reference numeral 76 in the attached drawing.

[0052] The device 76 includes a first feeding device 78 configured to feed a single continuous elastic membrane 80 in a direction X parallel to its longitudinal axis.

[0053] The device 10 includes a stretching unit 10 as described above, which includes a first stretching device 12 and a second stretching device 14.

[0054] A single continuous elastic membrane 80 is longitudinally cut in the longitudinal cutting unit 82 to form a first continuous elastic membrane 84 and a second continuous elastic membrane 86, which are fed to the stretching unit 10 by the second feeding device 88.

[0055] Device 10 includes an anvil 90 rotatable about a transverse axis of rotation. The anvil 90 has an outer cylindrical surface with a suction port pneumatically connected to a subatmospheric pressure source 91. Figure 5 The outer cylindrical surface of the anvil wheel 90 is tangent to the common transverse release line 72 of the tensioning unit 10.

[0056] The apparatus 10 includes a third feed device 92 and a fourth feed device 94, which are configured to feed a first nonwoven web 96 and a second nonwoven web 98 to an anvil 90, respectively. In one possible embodiment, each of the third feed device and the fourth feed device 94 may feed two parallel first nonwoven webs 96 and two parallel second nonwoven webs 98 to the anvil 90.

[0057] Reference Figure 4The rotation direction of the anvil wheel 90 indicated by the middle arrow 100 is such that the first nonwoven web 96 or two parallel first nonwoven webs 96 are applied to the anvil wheel 50 upstream of the common transverse release line 72 of the tension unit 10, and the second nonwoven web 98 or two parallel second nonwoven webs 98 are applied to the anvil wheel 90 downstream of the common transverse release line 72.

[0058] The device 76 includes a fastening device 102 that mates with the outer cylindrical surface of the anvil wheel 90. The fastening device 102 may be an ultrasonic welding device, a pressure device for fastening by adhesive, a thermal welding device, or a thermomechanical welding device.

[0059] The operation of device 76 described above is as follows.

[0060] A single continuous elastic membrane 80 is unrolled from a roll and longitudinally cut to form a first continuous elastic membrane 84 and a second continuous elastic membrane 86. The first continuous elastic membrane 84 and the second continuous elastic membrane 86 may have corresponding widths W1 that are equal to or different from each other. In possible embodiments, the first continuous elastic membrane 84 and the second continuous elastic membrane 86 may be unrolled from corresponding rolls. The first continuous elastic membrane 84 and the second continuous elastic membrane 86 may be the same as or different from each other; for example, they may be made of materials with different elastic properties.

[0061] refer to Figure 5 The side edges of the first continuous elastic membrane 84 and the second continuous elastic membrane 86 are clamped by the outer edges 24 and 26 of the corresponding first stretching device 12 and second stretching device 14 of the stretching unit 10.

[0062] The first stretching device 12 and the second stretching device 14 pick up a first continuous elastic membrane 84 and a second continuous elastic membrane 86, each having a corresponding first width W1, in their respective clamping areas 68, and rotate about their respective rotation axes 20 and 22. During the rotation of the stretching members 16 and 18, the two continuous elastic membranes 84 and 86 are stretched in the lateral direction Y along the path from the respective clamping area 68 to the respective release area 70. In the respective release area 70, the two continuous elastic membranes 84 and 86 have corresponding widths W2, which may be equal to or different from each other.

[0063] refer to Figure 4 The first nonwoven web 96 or two parallel first nonwoven webs 96 are applied to the outer cylindrical surface of the anvil 90 at or upstream of the common transverse release line 72.

[0064] While the first continuous elastic membrane 84 and the second continuous elastic membrane 86 are held stretched in the transverse direction Y, they separate from the outer edges 24, 26 of the corresponding first tension member 14 and the second tension member 16, and are applied to a first nonwoven web 96 held on the outer cylindrical surface of the anvil 90 in the corresponding release regions 70, 76, or to a corresponding parallel first nonwoven web 96, the release regions being aligned along a common transverse release line 72. The first continuous elastic membrane 84 and the second continuous elastic membrane 86 are held in a transversely stretched state on the outer cylindrical surface of the anvil 90, for example, by suction.

[0065] The fact that the first continuous elastic membrane 84 and the second continuous elastic membrane 86 are applied along the common transverse release line 72 onto the first nonwoven web 96 or onto the corresponding parallel first nonwoven web 96 ensures high precision in the mutual positioning between the two continuous elastic membranes 84, 86 and the first nonwoven web 96.

[0066] After the first continuous elastic membrane 84 and the second continuous elastic membrane 86 are applied to the first nonwoven web 96 or the corresponding parallel first nonwoven web 96 on the outer cylindrical surface of the anvil 90, the second nonwoven web 98 or two parallel second nonwoven webs 98 are applied to the anvil 90 above the two parallel continuous elastic membranes 84, 86, such that the elastic membranes 84, 86, which are elastically stretched in the transverse direction Y, are sandwiched between the first nonwoven web 96 and the second nonwoven web 98 or between two pairs of first nonwoven webs 96 and second nonwoven webs 98.

[0067] Then, the nonwoven webs 96, 98 are joined together by the fastening device 102 through two parallel and continuous first elastic membranes 84 and second elastic membranes 86 (e.g., by ultrasonic welding) to form a continuous elastic laminate 104 or two parallel and continuous elastic laminates 104.

[0068] Joining nonwoven webs 96 and 98 together by means of two parallel continuous elastic membranes 84 and 86 includes directly fastening the nonwoven webs 96 and 98 through openings in the elastic membranes 84 and 86, and fastening the nonwoven webs 96 and 98 to opposite sides of the elastic membranes 84 and 86.

[0069] The fastening device 102 can be configured to form a plurality of connection points that form corresponding holes through the elastic membranes 84, 86, and directly secure opposing nonwoven webs 94, 96 to each other through the holes formed in the elastic membranes 84, 86. The elastic membranes 84, 86 are held anchored to the nonwoven webs 96, 98 at the connection points extending through the holes formed in the elastic membranes 84, 86. The formation of holes through the elastic membranes 84, 86 provides a breathable elastic laminate.

[0070] Figure 6 A second embodiment of the apparatus 76 for producing elastic laminates is shown. Components corresponding to those previously disclosed are indicated by the same reference numerals.

[0071] exist Figure 6 In one embodiment, the device 76 includes a transfer wheel 106 disposed between the stretching unit 10 and the anvil wheel 90. The transfer wheel 106 rotates about a rotation axis parallel to the rotation axis of the anvil wheel 90 and has an outer cylindrical surface tangent to the outer cylindrical surface of the anvil wheel 90 along a transverse line.

[0072] The conveyor wheel 106 is provided with a clamping element configured to maintain a first continuous elastic membrane 84 and a second continuous elastic membrane 86 under lateral tension. In one possible embodiment, the clamping element may include a suction port that opens on the outer cylindrical surface of the conveyor wheel 106 and is pneumatically connected to a subatmospheric pressure source for maintaining the first continuous elastic membrane 84 and the second continuous elastic membrane 86 under lateral tension by suction. Alternatively or in lieu of a suction port, the clamping element may include a protruding pin.

[0073] The stretching unit 10 applies a laterally stretched first continuous elastic membrane 84 and a second continuous elastic membrane 86 to the outer cylindrical surface of the conveyor wheel 106 in a release region 70 aligned along a common transverse release line 72. In the release region 70, the first continuous elastic membrane 84 and the second continuous elastic membrane 86, stretched in the transverse direction Y, separate from the first stretching member 16 and the second stretching member 18 of the stretching unit 10, and are brought to the outer cylindrical surface of the conveyor wheel 106, for example, by suction.

[0074] Then, the first continuous elastic membrane 84 and the second continuous elastic membrane 86, stretched in the transverse direction Y, separate from the conveyor wheel 106 and are applied to a first nonwoven web 96 or two parallel first nonwoven webs 96 held on the outer cylindrical surface of the anvil wheel 90. In one possible embodiment, the first nonwoven web 96 or the two parallel first nonwoven webs 96 may be applied to the outer cylindrical surface of the anvil wheel 90 above the transversely stretched elastic membranes 84, 86 by first applying them to the conveyor wheel 106.

[0075] exist Figure 6 In this embodiment, two parallel, continuous elastic membranes 84, 86 (made of a non-porous material) are applied to directly contact the outer cylindrical surface of the transfer wheel 40 without the intervention of a porous material layer. This allows the continuous elastic membranes 84, 86 to be held in a laterally stretched state with high precision. Furthermore, the two parallel, continuous elastic membranes 84, 86 are transferred from the transfer wheel 106 to the anvil wheel 90 between two tangential cylindrical surfaces, which simplifies the transfer of the elastic membranes and avoids positioning errors that can occur when the elastic membranes are applied to the nonwoven web starting from a surface with an inclined axis.

[0076] refer to Figure 6 The device 76 may include at least one longitudinal cutting device 108 configured to cut a transversely stretched continuous elastic membrane 84, 86 held on the outer cylindrical surface of the conveyor wheel 106 along at least one longitudinal cutting line.

[0077] In a possible embodiment, the stretching unit 10 can apply a single continuous elastic membrane 80 onto a conveyor wheel 106, where the elastic membrane is longitudinally cut. The single continuous elastic membrane 80 can be longitudinally cut along multiple parallel cut lines to form two or more parallel continuous elastic membranes.

[0078] The longitudinal cutting device 108 may include a cutting disc 109 that rotates about an axis parallel to the axis of rotation of the conveyor wheel 106. The cutting disc 109 may engage with a corresponding circumferential slot formed on the outer cylindrical surface of the conveyor wheel 106.

[0079] In one possible embodiment, the apparatus may include a longitudinal cutting device arranged to perform longitudinal cuts on one or more consecutive elastic films on an anvil 90. The longitudinal cutting device can cut the elastic film without cutting the underlying nonwoven web.

[0080] The equipment according to the invention offers great flexibility in terms of the possibility of producing different types of elastic laminates.

[0081] refer to Figure 7 A first embodiment of the elastic laminate 110 includes a first continuous elastic membrane 84 and a second continuous elastic membrane 86 sandwiched between a first wide nonwoven web 96 and a second wide nonwoven web 98 and fixed to the two nonwoven webs 96, 98 by a pattern of connection points 112. The elastic laminate 110 may have an inelastic portion 114 in which the elastic membranes 84, 86 are laterally spaced apart from each other and the two nonwoven webs 96, 98 are in direct contact with each other. The two wide nonwoven webs 96, 98 are directly fixed to each other in the inelastic portion 114 included between the two parallel continuous elastic membranes 84, 86 and along the longitudinal edges outside the elastic membranes 84, 86. The fastening device 102 may be configured to perform a uniform fastening pattern on the entire surface of the nonwoven webs 96, 98 at the elastic membranes 84, 86 and in the inelastic portion 114.

[0082] The device according to the invention may include a cutting unit configured to form a longitudinal weakening line on the inelastic portion 114, the longitudinal weakening line forming a preferential break line, which allows the two elastic portions of the elastic laminate 104 to separate from each other after a weak separation force is applied.

[0083] refer to Figure 8The apparatus according to the invention can produce two separate continuous elastic laminates 110, each continuous elastic laminate comprising a continuous elastic film 84, 86 sandwiched between a corresponding first narrow nonwoven web 96 and a second narrow nonwoven web 98. Figure 8 The two continuous elastic laminates 110 can be produced by feeding two separate first narrow nonwoven webs 96 and two separate second narrow nonwoven webs 98 onto an anvil, which overlap with the corresponding first continuous elastic film 84 and second continuous elastic film 86.

[0084] exist Figure 7 and Figure 8 In the embodiments, the first continuous elastic membrane 84 and the second continuous elastic membrane 86 may have the same or different widths, they may be stretched laterally at the same or different stretching rates W2 / W1, and they may be made of the same or different materials.

[0085] refer to Figure 9 The apparatus according to the invention can also produce an elastic laminate 110 having a single wide continuous elastic film 80 sandwiched between a first wide nonwoven web 96 and a second wide nonwoven web 98. Figure 9 The elastic laminate 110 can be produced by laterally stretching a single continuous elastic membrane 80 by two second stretching members 18 of the stretching unit 10. The two first stretching members 16 of the stretching unit 10 can be disconnected from the sub-atmospheric pressure source and moved away from the common lateral release line 72 in the direction X, so that they do not interfere with the single continuous elastic membrane 80.

[0086] refer to Figure 10 The apparatus according to the invention can also produce an elastic laminate 110 having only a continuous elastic membrane 84 sandwiched between a first wide nonwoven web 96 and a second wide nonwoven web 98, the first wide nonwoven web and the second wide nonwoven web forming a wide inelastic portion 116 extending laterally toward the continuous elastic membrane 84. Figure 10 The elastic laminate 110 can be produced by laterally stretching a single continuous elastic membrane 84 through two stretching members 16, 18 of a single stretching device 12 in the stretching unit 10. The inelastic portion 116 can extend to the left or right of the continuous elastic membrane 84. In one possible embodiment, the single continuous elastic membrane 84 can be centrally closed between two wide nonwoven webs 96, 98, which form a wide inelastic portion 116 extending laterally from opposite sides of the single continuous elastic membrane 84. In another possible embodiment, the single continuous elastic membrane 84 can be laterally closed between a wide nonwoven web and a narrow nonwoven web.

[0087] The width of the wide nonwoven webs 96 and 98 is greater than the width of the first continuous elastic membrane 84 and the second continuous elastic membrane 86 arranged side by side, and the width of the narrow nonwoven webs 96 and 98 is less than the width of the wide nonwoven webs 96 and 98, but greater than the width of one continuous elastic membrane 84 and 86.

[0088] The device may include one or two winding units configured to wind one or two elastic laminates 110 onto one or two reels.

[0089] Of course, without prejudice to the principles of the invention, the details of the construction and embodiments may be extensively changed with respect to those details described and shown, and thus without departing from the scope of the invention as defined by the appended claims.

Claims

1. A stretching unit for laterally stretching an elastic membrane, the stretching unit comprising first and second stretching devices, each of the first and second stretching devices comprising first and second stretching members, the first and second stretching members having corresponding outer edges, the corresponding outer edges being provided with clamping elements configured to clamp corresponding edges of the elastic membrane. in, The first and second tension members have corresponding first and second axes of rotation that are inclined relative to each other. The first and second stretching devices each have a corresponding clamping area and a corresponding release area, and the release areas of the first and second stretching devices are aligned with each other along a common transverse release line. The first and second tensioning devices are disposed on opposite sides of a central plane orthogonal to the common transverse release line. Each of the first and second tensioning devices includes a corresponding drive assembly configured to drive the corresponding first and second tensioning members to rotate about corresponding first and second rotation axes. In each of the first and second stretching devices, the drive assembly extends only on one side relative to the central plane, and The drive assembly of each of the first and second tensioning devices includes first and second motors connected to the respective first and second tensioning members at respective first and second rotation axes that are inclined relative to each other.

2. The tensioning unit according to claim 1, wherein, The drive assembly of the first tensioning device and the drive assembly of the second tensioning device are arranged on opposite sides of the central plane.

3. The tensioning unit according to claim 1, wherein, The first and second stretching members of each of the first and second stretching devices include a plurality of suction holes pneumatically connected to a corresponding fixed suction chamber, wherein the fixed suction chambers of each of the first and second stretching devices are arranged on the same side relative to the central plane.

4. The tensioning unit according to claim 3, wherein, The fixed suction chamber of each of the first and second stretching devices is coaxial with the corresponding first and second stretching members.

5. The tensioning unit according to claim 3, wherein, The fixed suction chambers of the first and second stretching devices, connected to the first and second stretching members, can be selectively connected to and disconnected from a subatmospheric pressure source, the first and second stretching members being located distal to the respective drive assemblies.

6. The stretching unit according to claim 3, wherein, The fixed suction chambers of the first stretching device and the second stretching device are arranged on opposite sides of the central plane.

7. The tensioning unit according to claim 1, wherein, Each of the first and second tensioning devices includes first and second adjustment mechanisms configured to adjust the tilt angles of the first and second rotation axes of the respective first and second tensioning members, wherein the first and second adjustment mechanisms of each of the first and second tensioning devices are arranged on the same side relative to the central plane.

8. The tensioning unit according to claim 7, wherein, The first and second adjustment mechanisms of the first tensioning device and the first and second adjustment mechanisms of the second tensioning device are arranged on opposite sides of the central plane.

9. The tensioning unit according to claim 1, wherein, The first and second tensioning members of each of the first and second tensioning devices are spaced apart from each other in the clamping region by a first distance in the lateral direction, and are spaced apart from each other by a second distance greater than the first distance in the release region, wherein the first distance and / or the second distance of the first tensioning device is different from the first distance and / or the second distance of the second tensioning device.

10. The tensioning unit according to claim 1, wherein, In each of the first and second tensioning devices, the first and second tensioning members are located on the distal and proximal sides of the respective drive assembly, respectively, and wherein the first tensioning members of the first and second tensioning devices face opposite sides of the central plane.

11. The tensioning unit according to claim 1, wherein, Each of the first and second tension members is disc-shaped.

12. A machine for manufacturing an elastic laminate or for manufacturing a sanitary article comprising at least one elastic laminate, said machine comprising a stretching unit according to claim 1.

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