METHOD AND APPARATUS FOR PRODUCING ELASTIC LAMINATES
20230040222 ยท 2023-02-09
Inventors
- Gabriele SABLONE (San Giovanni Teatino (Chieti), IT)
- Antonio D'ALBERTO (San Giovanni Teatino (Chieti), IT)
Cpc classification
B29C66/1122
PERFORMING OPERATIONS; TRANSPORTING
B29C66/83415
PERFORMING OPERATIONS; TRANSPORTING
B29C66/344
PERFORMING OPERATIONS; TRANSPORTING
B32B27/12
PERFORMING OPERATIONS; TRANSPORTING
B29C66/433
PERFORMING OPERATIONS; TRANSPORTING
B32B2305/20
PERFORMING OPERATIONS; TRANSPORTING
B32B37/20
PERFORMING OPERATIONS; TRANSPORTING
B32B37/0046
PERFORMING OPERATIONS; TRANSPORTING
A61F13/15593
HUMAN NECESSITIES
B32B38/0012
PERFORMING OPERATIONS; TRANSPORTING
B29C55/08
PERFORMING OPERATIONS; TRANSPORTING
B29C66/83411
PERFORMING OPERATIONS; TRANSPORTING
B32B2250/40
PERFORMING OPERATIONS; TRANSPORTING
B32B7/035
PERFORMING OPERATIONS; TRANSPORTING
B32B37/06
PERFORMING OPERATIONS; TRANSPORTING
International classification
B32B37/20
PERFORMING OPERATIONS; TRANSPORTING
B32B37/00
PERFORMING OPERATIONS; TRANSPORTING
B32B37/06
PERFORMING OPERATIONS; TRANSPORTING
B32B38/00
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A method for producing elastic laminates includes gripping first and second continuous elastic films in respective gripping zones by respective first and second stretching members, transversely stretching the first and second continuous elastic films by rotating said first and second stretching members about respective first and second axes of rotation inclined with respect to each other, and releasing the transversely stretched first and second continuous elastic films from the respective first and second stretching members in respective release zones aligned along a common transverse release line.
Claims
1. A method for producing elastic laminates, comprising: providing first and second continuous elastic films and feeding the first and second continuous elastic films along respective longitudinal directions parallel to each other, providing a stretching unit comprising first and second stretching devices each comprising first and second stretching members rotating about respective first and second axes of rotation inclined with respect to each other, the first and second stretching devices having respective gripping zones and respective release zones, wherein the release zones of the first and second stretching devices are aligned to each other along a common transverse release line, gripping the first and second continuous elastic films in respective gripping zones by said first and second stretching members, transversely stretching the first and second continuous elastic films by rotating said first and second stretching members about said first and second axes of rotation, releasing the transversely stretched first and second continuous elastic films from the respective first and second stretching members in respective release zones aligned along the common transverse release line, applying nonwoven webs on opposite sides of the transversely stretched first and second continuous elastic films, and bonding said nonwoven webs to the transversely stretched first and second continuous elastic films on an anvil wheel.
2. The method of claim 1, wherein the first and second continuous elastic films are different from each other.
3. The method of claim 1, wherein the first and second continuous elastic films are obtained by cutting a single continuous elastic film along a longitudinal cutting line.
4. The method of claim 1, wherein in the respective gripping zones, the first and second continuous elastic films have respective widths different from each other.
5. The method of claim 1, wherein in the respective release zones, the first and second continuous elastic films have respective widths different from each other.
6. The method of claim 1, wherein the first and second continuous elastic films are transversely stretched with respective stretching rates different from each other.
7. The method of claim 1, comprising: applying a first nonwoven web or a pair of first nonwoven webs on an outer cylindrical surface of said anvil wheel, applying said transversally stretched first and second continuous elastic films on the first nonwoven web or pair of first nonwoven webs held on the outer cylindrical surface of the anvil wheel, applying a second nonwoven web or a pair of second nonwoven webs on the anvil wheel above said transversally stretched first and second continuous elastic films, and bonding the first and second nonwoven webs or the pairs of first and second nonwoven webs to the transversely stretched first and second continuous elastic films on said anvil wheel.
8. The method of claim 7, comprising: applying said transversally stretched first and second continuous elastic films on an outer cylindrical surface of a transfer wheel, and transferring said transversally stretched first and second continuous elastic films on the first nonwoven web or pair of first nonwoven webs held on the outer cylindrical surface of the anvil wheel.
9. An apparatus for producing elastic laminates, comprising: a feeding device configured for feeding first and second continuous elastic films along respective longitudinal directions parallel to each other, a stretching unit comprising first and second stretching devices each comprising first and second stretching members rotating about respective first and second axes of rotation inclined with respect to each other, the first and second stretching devices having respective gripping zones and respective release zones, wherein the release zones of the first and second stretching devices are aligned to each other along a common transverse release line, an anvil wheel configured for receiving from the stretching unit the first and second continuous elastic films stretched in a transverse direction, and for applying nonwoven webs on opposite sides of the transversely stretched first and second continuous elastic films, and a fastening device configured for bonding said nonwoven webs to the transversely stretched first and second continuous elastic films on said anvil wheel.
10. The apparatus of claim 9, comprising a transfer wheel configured for receiving said transversally stretched first and second continuous elastic films from said stretching unit and for transferring said transversally stretched first and second continuous elastic films on the anvil wheel.
11. The apparatus of claim 9, comprising a longitudinal cutting unit arranged upstream of said stretching unit and configured for cutting in a longitudinal direction a single continuous elastic film so as to form said first and second continuous elastic films.
12. The apparatus of claim 9, comprising a cutting device configured for cutting in a longitudinal direction at least one of the first and second continuous elastic films on said transfer wheel or on said anvil wheel.
13. The apparatus of claim 9, comprising one or two winding units configured for winding one or two elastic laminates in one or two reels.
14. A machine for manufacturing an elastic laminate or for manufacturing sanitary articles including at least one elastic laminate, comprising the apparatus according to claim 9.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present invention will now be described in detail with reference to the attached drawings, given purely by way of non-limiting example, wherein:
[0017]
[0018]
[0019]
[0020]
[0021]
[0022]
[0023]
[0024] It will be appreciated that in the drawings some components may not be illustrated to simplify the understanding of the figures, and that various figures may not be represented on the same scale.
DETAILED DESCRIPTION
[0025] With reference to
[0026] The stretching unit 10 comprises a first stretching device 12 and a second stretching device 14. The first and second stretching devices 12, 14 are substantially identical to each other.
[0027] Each of the first and second stretching devices 12, 14 comprises first and second stretching members 16, 18 rotating about respective first and second axes of rotation 20, 22 (
[0028] The first and second stretching members 16, 18 may be disk-shaped, as shown in the drawings. In possible embodiments, the first and second stretching members 16, 18 may have a shape different from that of a disk.
[0029] The first and second stretching members 16, 18 have respective outer edges 24, 26 provided with gripping elements for gripping corresponding side edges of an elastic film. The gripping elements may be suction holes 28 open on the outer edges 24, 26 and connected to a sub-atmospheric pressure source, as it will be disclosed in the following. The outer edges 24, 26 of the stretching members 16, 18 may be provided with protruding pins that engage the side edges of an elastic film, alternatively or in addition to the suction holes 28.
[0030] With reference to
[0031] The driving assembly 30 of each of the first and second stretching devices 12, 14 is arranged on only one side with respect to the respective stretching members 16, 18. More specifically, the first and second stretching members 16, 18 of each of the first and second stretching devices 12, 14 are respectively distal and proximal with respect to the respective driving assembly 30, and the driving assembly 30 extends on only one side with respect to the first stretching member 16.
[0032] In the embodiment shown in the figures, the driving assembly 34 of each of the first and second stretching devices 12, 14 comprises first and second motors 32, 34 which drive respectively the first and second stretching members 16, 18. Each motor 32, 34 may comprise a respective reduction gear. In each of the first and second stretching devices 12, 14 both motors 32, 34 are arranged on only one side with respect to the respective stretching members 16, 18.
[0033] In possible embodiments, the driving assembly 30 of each of the first and second stretching devices 12, 14 may comprise a single motor and a joint assembly which connects the single motor to the respective first and second stretching members 16, 18. In this embodiment, in of each of the first and second stretching devices 12, 14 the single motor and the joint assembly are arranged on only one side with respect to the respective stretching members 16, 18.
[0034] The first motor 32 may be coaxial to the respective first stretching member 16 and may be connected thereto via a first shaft 36. The second motor 34 may be eccentric to the respective second stretching member 18 and may be connected thereto by a second shaft 38 and by a belt transmission including a toothed belt 40 and a pair of toothed pulleys.
[0035] With reference to
[0036] In a possible embodiment, the stationary suction chambers 44, 46 of each of the first and second stretching devices 12, 14 are coaxial to the respective first and second stretching members 16, 18.
[0037] In a possible embodiment, the suction chambers 44 of the first and second stretching devices 16, 18 connected to stretching members 16 which are distal with respect to the respective driving assembly 30 are selectively connectable and disconnectable from a sub-atmospheric pressure source, so that the stretching unit 10 may operate with only the outer stretching members 18 while the inner stretching members 16 are inoperative.
[0038] With reference to
[0039] Each of the of the first and second adjustment mechanisms 52, 54 is configured for adjusting the angle of inclination of the axis of rotation 20, 22 of the respective first and second stretching members 16, 18.
[0040] The first and second adjustment mechanisms 52, 54 of each of the first and second stretching devices 12, 14 are arranged on the side of the respective first and second stretching members 16, 18 facing the respective driving assembly 30.
[0041] With reference to
[0042] Each adjustable support structure 58 rotatably supports a respective first shaft 36 or second shaft 38. Therefore, an angular adjustment of the adjustable support structure 58 about the adjustment axis 60 changes the inclination of the respective first axis of rotation 20 or second axis of rotation 22.
[0043] The stationary suction chambers 44, 46 of each of the first and second stretching devices 12, 14 are supported by the adjustable support structure 58 of a respective first and second adjustment mechanism 52, 54. Therefore, when the inclination of the axes of rotation 20, 22 of the first and second stretching members 16, 18 is adjusted, the relative position between the first and second stretching members 16, 18 and the respective stationary suction chambers 44, 46 does not change.
[0044] The base 56 of each of the first and second adjustment mechanisms 52, 54 may comprise respective guides 64 which allow adjustment of the position of the respective first and second adjustment mechanisms 52, 54 along a transverse direction Y.
[0045] Each of the first and second adjustment mechanisms 52, 54 may comprise an auxiliary adjustment device 66 which allow adjustment of the position of the respective first and second stretching members 16, 18 along a linear direction X and/or Z orthogonal to the transverse direction Y. The auxiliary adjustment devices 66 may be controlled manually or by respective motors (not shown).
[0046] With reference to
[0047] The first and second stretching members 16, 18 of each of the first and second stretching devices 12, 14 are spaced from each other in the transverse direction Y by first distance W1 in the gripping zones 68 and by a second distance W2 greater than the first distance W1 in the release zones 70. The distances W1, W2 of the first and second stretching device 12, 14 may be equal to or different from each other.
[0048] With reference in particular to
[0049] With reference to
[0050] In each of the first and second stretching devices 12, 14 the respective driving assembly 30, stationary suction chambers 44, 46 and adjustment mechanisms 52, 54 extend on only one side of the central plane 74. The driving assembly 30, stationary suction chambers 44, 46 and adjustment mechanisms 52, 54 of the first and second stretching device 12, 14 extend on opposite sides of the central plane 74.
[0051] With reference to
[0052] The apparatus 76 comprises a first feeding device 78 configured to feed a single continuous elastic film 80 in a direction X parallel to its longitudinal axis.
[0053] The apparatus 10 comprises a stretching unit 10 as previously disclosed, including first and second stretching devices 12, 14.
[0054] The single continuous elastic film 80 is cut longitudinally in a longitudinal cutting unit 82 so as to form first and second continuous elastic films 84, 86 which are fed to the stretching unit 10 by a second feeding device 88.
[0055] The apparatus 10 comprises an anvil wheel 90 rotatable about a transverse axis of rotation. The anvil wheel 90 has an outer cylindrical surface provided with suction holes pneumatically connected to a source of sub-atmospheric pressure 91 (
[0056] The apparatus 10 comprises a third feeding device 92 and a fourth feeding device 94 configured to feed to the anvil wheel 90 first and second nonwoven webs 96, 98, respectively. In a possible embodiment, each of the third feeding device and fourth feeding devices 94 may feed to the anvil wheel 90 two parallel first nonwoven webs 96 and two parallel second nonwoven webs 98.
[0057] The first nonwoven web 96 or the two parallel first nonwoven webs 96 is/are applied to the anvil wheel 50 upstream of the common transverse release line 72 of the stretching unit 10, and the second nonwoven web 98 or the two parallel second nonwoven webs 98 is/are applied to the anvil wheel 90 downstream of the common transverse release line 72, with reference to the direction of rotation of the anvil wheel 90 indicated by the arrow 100 in
[0058] The apparatus 76 comprises a fastening device 102 cooperating 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, or a thermal or thermomechanical welding device.
[0059] The operation of the apparatus 76 previously described is the following.
[0060] The single continuous elastic film 80 is unwound from a reel and is cut longitudinally to form first and second continuous elastic films 84, 86. The first and second continuous elastic films 84, 86 may have respective width W1 equal to or different from each other. In a possible embodiment, the first and second continuous elastic films 84, 86 may be unwound from respective reels. The first and second continuous elastic films 84, 86 may be equal or different from each other, e.g. they may be made of materials with different elastic properties.
[0061] With reference to
[0062] The first and second stretching devices 12, 14 pick-up the first and second continuous elastic films 84, 86 in the respective gripping zones 68 with respective first width W1 and rotate about the respective axes of rotation 20, 22. During the rotation of the stretching members 16, 18, the two continuous elastic films 84, 86 are stretched in a transverse direction Y in the path from the respective gripping zones 68 to the respective release zones 70. In the respective release zones 70 the two continuous elastic films 84, 86 have respective width W2, which may be equal to or different from each other.
[0063] With reference to
[0064] The first and second continuous elastic films 84, 86, while held stretched in the transverse direction Y, are detached from the outer edges 24, 26 of the respective first and second stretching members 14, 16 and are applied onto the first nonwoven web 96 or on respective parallel first nonwoven webs 96 held on the outer cylindrical surface of the anvil wheel 90 in the respective release zones 70, 76, aligned along the common transverse release line 72. The first and second continuous elastic films 84 86 are kept in a transversely stretched state on the outer cylindrical surface of the anvil wheel 90, e.g. by suction.
[0065] The fact of applying the first and second continuous elastic films 84, 86 on the first nonwoven web 96 or on respective parallel first nonwoven webs 96 along the common transverse release line 72 ensures a high accuracy of mutual positioning between the two continuous elastic films 84, 86 and the first nonwoven web(s) 96.
[0066] After applying the first and second continuous elastic films 84, 86 on the first nonwoven web 96 or on respective parallel first nonwoven webs 96 on the outer cylindrical surface of the anvil wheel 90, the second nonwoven web 98 or two parallel second nonwoven webs 98 is/are applied on the anvil wheel 90 above the two parallel continuous elastic films 84, 86 so that the elastic films 84, 86, elastically stretched in the transverse direction Y, are sandwiched between the first and the second nonwoven webs 96, 98 or between two pairs of first and the second nonwoven webs 96, 98.
[0067] Then, the nonwoven webs 96, 98 are joined together, for example by ultrasonic welding, through the two parallel continuous first and second elastic films 84, 86 by the fastening device 102, thereby forming a continuous elastic laminate 104 or two parallel continuous elastic laminates 104.
[0068] Joining to each other the nonwoven webs 96, 98 through the two parallel continuous elastic films 84, 86 includes both the direct fastening of the nonwoven webs 96, 98 through openings in the elastic films 84, 86, and fastening of the nonwoven webs 96, 98 on opposite sides of the elastic films 84, 86.
[0069] The fastening device 102 may be configured to form a plurality of connecting points that form respective holes passing through the elastic films 84 86, and that directly fix the opposite nonwoven webs 94, 96 to each other through the holes formed in the elastic films 84, 86. The elastic films 84, 86 remain anchored to the nonwoven webs 96, 98 at the connecting points that extend through the holes formed in the elastic films 84, 86. This provides breathable elastic laminates thanks to the formation of holes passing through the elastic films 84 86.
[0070]
[0071] In the embodiment of
[0072] The transfer wheel 106 is provided with gripping elements configured to hold the transversally stretched first and second continuous elastic films 84, 86. In a possible embodiment, the gripping elements may consist of suction holes open on the outer cylindrical surface of the transfer wheel 106 and pneumatically connected to a source of sub-atmospheric pressure, for retaining by suction the transversally stretched first and second continuous elastic films 84, 86. The gripping elements may comprise projecting pins, in addition or in alternative to suction holes.
[0073] The stretching unit 10 applies the transversally stretched first and second continuous elastic films 84, 86 on the outer cylindrical surface of the transfer wheel 106 in the release zones 70 aligned along the common transverse release line 72. In the release zones 70 the first and second continuous elastic films 84, 86 stretched in the transversal direction Y are detached from the first and second stretching members 16, 18 of the stretching unit 10 and are taken, e.g. by suction, on the outer cylindrical surface of the transfer wheel 106.
[0074] The first and second continuous elastic films 84, 86 stretched in the transversal direction Y are then detached from the transfer wheel 106 and are applied on the first nonwoven web 96 or on the two parallel first nonwoven webs 96 held on the outer cylindrical surface of the anvil wheel 90. In a 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 by first being applied to the transfer wheel 106, above the transversally stretched elastic films 84, 86.
[0075] In the embodiment of
[0076] With reference to
[0077] In a possible embodiment, the stretching unit 10 may apply to the transfer wheel 106 a single continuous elastic film 80, which is cut longitudinally on the transfer wheel 106. The single continuous elastic film 80 may be cut longitudinally along a plurality of parallel cutting lines so as to form more than two parallel continuous elastic films.
[0078] The longitudinal cutting device 108 may comprise a cutting disk 109 rotating about an axis parallel to the axis of rotation of the transfer wheel 106. The cutting disk 109 may cooperate with a respective circumferential slot formed on the outer cylindrical surface of the transfer wheel 106.
[0079] In a possible embodiment, the apparatus may comprise a longitudinal cutting device arranged for carrying out the longitudinal cut of one or more continuous elastic films on the anvil wheel 90. The longitudinal cutting device may cut the elastic films without cutting the underneath nonwoven webs.
[0080] The apparatus according to the present invention has a great flexibility regarding the possibility to produce different types of elastic laminates.
[0081] With reference to
[0082] The apparatus according to the present invention may comprise a cutting unit configured for forming a longitudinal weakening line on the non-elastic portion 114, which forms a preferential breaking line which allows the two elastic parts of the elastic laminate 104 to be detached from each other following the application of a weak detaching force.
[0083] With reference to
[0084] In the embodiments of
[0085] With reference to
[0086] With reference to
[0087] A wide nonwoven web 96, 98 has a width greater than the width of the first and second continuous elastic films 84, 86 set side by side, and a narrow nonwoven web 96, 98 has a width lower than the width of a wide nonwoven web 96, 98 and greater than the width of one continuous elastic films 84, 86.
[0088] The apparatus may comprise one or two winding units configured for winding one or two elastic laminates 110 in one or two reels.
[0089] Of course, without prejudice to the principle of the invention, the details of construction and the embodiments can be widely varied with respect to those described and illustrated, without thereby departing from the scope of the invention as defined by the claims that follow.