Elastic composite sheet manufacturing method
11540954 · 2023-01-03
Assignee
Inventors
Cpc classification
B29C55/06
PERFORMING OPERATIONS; TRANSPORTING
A61F13/15764
HUMAN NECESSITIES
B32B27/12
PERFORMING OPERATIONS; TRANSPORTING
B29C48/345
PERFORMING OPERATIONS; TRANSPORTING
B29C48/92
PERFORMING OPERATIONS; TRANSPORTING
A61F13/15593
HUMAN NECESSITIES
A61F13/15707
HUMAN NECESSITIES
B32B7/05
PERFORMING OPERATIONS; TRANSPORTING
B32B2274/00
PERFORMING OPERATIONS; TRANSPORTING
B32B2250/40
PERFORMING OPERATIONS; TRANSPORTING
B29C48/0021
PERFORMING OPERATIONS; TRANSPORTING
B29C48/0018
PERFORMING OPERATIONS; TRANSPORTING
International classification
A61F13/15
HUMAN NECESSITIES
B29C48/00
PERFORMING OPERATIONS; TRANSPORTING
Abstract
An elastic resin material having a thermoplastic elastic resin as a main component is heated and melted, and the elastic resin material is discharged in a film or a linear shape from a discharge mechanism to form a film-shape or a linear-shape intermediate product. At a temperature above the temperature region at which the elastic resin material elastically deforms, extending is performed until the thickness or width of the film-shape intermediate product or the thickness of the linear-shape intermediate product assumes a prescribed value; with a cooling roller, the intermediate product is cooled to the temperature region at which the elastic resin material elastically deforms, and the intermediate product is hardened, forming a film-shape or linear-shape elastic member. The elastic member is stretched with a stretch roller to a prescribed stretching ratio, and the stretched elastic member is laminated on and bonded to a first base material sheet.
Claims
1. An elastic composite sheet manufacturing method comprising: a first step of heating and melting an elastic resin material having a thermoplastic elastic resin as a main component; a second step of forming a film-shape or a linear-shape intermediate product by discharging the melted elastic resin material in a film or a linear shape; a third step of extending the intermediate product at a temperature higher than a temperature region at which the elastic resin material elastically deforms, until a thickness or width of the film-shape intermediate product or a thickness of the linear-shape intermediate product assumes a prescribed value; a fourth step of forming a film-shape or a linear-shape elastic member by contacting the intermediate product with a cooling member, so as to cool the intermediate product to a temperature region at which the elastic resin material elastically deforms and hardening the intermediate product; a fifth step of stretching the elastic member to a prescribed stretching ratio; and a sixth step of laminating the stretched elastic member on a first base material sheet and bonding the elastic member to the first base material sheet, wherein at the third and fourth steps, by providing a plurality of cooling members having different temperature conditions so that the intermediate product passes the cooling members successively, the intermediate product is cooled in a plurality of steps, and wherein at the third and fourth steps, a condition for cooling the intermediate product is made to vary along a width direction of the film-shape intermediate product or along a direction in which a plurality of the linear-shape intermediate products are arranged.
2. The elastic composite sheet manufacturing method according to claim 1, wherein at the sixth step, a second base material sheet is superposed on the elastic member and the first base material sheet in such a manner that the elastic member is sandwiched between the first base material sheet and the second base material sheet, the second base material sheet is bonded to at least one of the stretched elastic member and the first base material sheet, or the second base material sheet is bonded to the first base material sheet, the elastic member is not bonded to the first base material sheet or the second base material sheet and only by friction between the first base material sheet and the second base material sheet, the elastic member is held between the first base material sheet and the second base material sheet.
3. The elastic composite sheet manufacturing method according to claim 1, wherein at the third step, the intermediate product is extended by periodically changing the prescribed value to which the intermediate product is extended.
4. The elastic composite sheet manufacturing method according to claim 1, wherein at the fifth step, the elastic member is stretched while the prescribed stretching ratio to which the elastic member is stretched is periodically changed.
5. The elastic composite sheet manufacturing method according to claim 1, further comprising, after bonding the stretched elastic member to the first base material sheet, releasing a stretched state so that the first base material sheet is curved to form projections and depressions.
6. The elastic composite sheet manufacturing method according to claim 1, wherein in the fourth step, the intermediate product after the third step contacts lateral and lower sides of the cooling member to cool the intermediate product.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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SECOND EMBODIMENT
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MODE FOR CARRYING OUT THE INVENTION
(9) Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(10) <First embodiment> A manufacturing method and manufacturing device of an elastic composite sheet of a first embodiment will be described with reference to
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(12) The discharge mechanism 20 discharges a heat-melted elastic resin material in a film or a linear shape to form a film-shape or a linear-shape intermediate product 2. The elastic resin material has a thermoplastic elastic resin as the main component, and is heat-melted to a temperature higher than a temperature region at which the elastic resin material elastically deforms.
(13)
(14) As shown in
(15) In the cooling roller 30, a non-illustrated flow path where a coolant flows is formed, and in a second section 82 in which the intermediate product 2 is in contact with the outer peripheral surface of the cooling roller 30, the cooling roller 30 cools the intermediate product 2 to the temperature region at which the elastic resin material forming the intermediate product 2 elastically deforms, and hardens it. Thereby, the intermediate product 2 becomes a film-shape or linear-shape elastic member 3 in the second section 82, and is drawn from the cooling roller 30.
(16) The elastic member 3 is sent to the stretch mechanism 38 by way of a guide roller 32. The guide roller 32 may be provided with a cooling function. The stretch mechanism 38 includes a drawing roller 34, a pinch roller 36 and a stretch roller 40. The elastic member 3 is sandwiched between the drawing roller 34 and the pinch roller 36 so as not to slide along the outer peripheral surface of the drawing roller 34. The rotation of the drawing roller 34 synchronizes with the rotation of the cooling roller 30.
(17) The elastic member 3 is stretched in a third section 84 from when it is between the drawing roller 34 and the pinch roller 36 to when it reaches the stretch roller 40. That is, the stretch roller 40 rotates at a circumferential speed higher than that of the drawing roller 34 to stretch the elastic member 3 at a prescribed stretching ratio. The elastic member 3 being stretched is along the outer peripheral surface of the stretch roller 40.
(18) The laminating mechanism 48 supplies continuous first nonwoven fabric 4 as a first base material sheet to the stretch roller 40 through a guide roller 50, and supplies continuous second nonwoven fabric 6 as a second base material sheet to the stretch roller 40 through guide rollers 52 and 54. The elastic member 3 stretched along the stretch roller 40 is sandwiched between the first nonwoven fabric 4 and the second nonwoven fabric 6, so that a laminated body 7 in which the elastic member 3, the first nonwoven fabric 4 and the second nonwoven fabric 6 are laminated is formed.
(19) The laminated body 7 moves with the rotation of the stretch roller 40, and passes between the stretch roller 40 and a horn 43 of an ultrasonic bonding device 42. The horn 43 comes into contact with and separates from the stretch roller 40 and when the laminated body 7 is sandwiched between the stretch roller 40 and the horn 43, the elastic member 3 and the first and second nonwoven fabrics 4 and 6 are supersonically bonded. Thereby, an elastic composite sheet 8 in which the elastic member 3 and the first and second nonwoven fabrics 4 and 6 are intermittently bonded is formed and drawn from the laminating mechanism 48. Regarding the first and second nonwoven fabrics 4 and 6, parts thereof directly opposing without the elastic member 3 in between may be supersonically bonded together.
(20) Specifically, the stretch roller 40 has, on its outer peripheral surface, a plurality of non-illustrated protrusions formed at intervals from one another, and functions as an anvil. Of the laminated body 7, the parts sandwiched between the protrusions of the stretch roller 40 and the horn 43 are supersonically bonded. By the supersonic bonding, desired parts can be easily and accurately bonded.
(21) Instead of supersonic bonding, the elastic member 3 and the first and second nonwoven fabrics 4 and 6 of the laminated body 7 may be heat-welded by heat sealing or the like, or the elastic member 3 and the first and second nonwoven fabrics 4 and 6 of the laminated body 7 may be bonded by using an adhesive agent.
(22) Moreover, the elastic member 3 may be held between the first nonwoven fabric 4 and the second nonwoven fabric 6 only by the friction between the first nonwoven fabric 4 and the second nonwoven fabric 6 without being bonded to the first nonwoven fabric 4 or the second nonwoven fabric 6. For example, the first and second nonwoven fabrics 4 and 6 are bonded together at an interval smaller than the width of the elastic member 3 in a relaxed state on both sides in the width direction of the elastic member 3 in a stretched state; then, the stretched state of the elastic member 3 is released, and the elastic member 3 having become thick because of the relaxing is sandwiched between the bonded parts of the first and second nonwoven fabrics 4 and 6 so that the elastic member 3 is brought into a state of being held between the first and second nonwoven fabrics 4 and 6 by the frictional force caused between the elastic member 3 and the first and second nonwoven fabrics 4 and 6.
(23) Two or more bonding modes may be combined.
(24) The stretch roller 40 serves both as the stretch mechanism 38 and the laminating mechanism 48. While this simplifies the structure of the elastic composite sheet manufacturing device 10, a structure provided with separate rollers as the stretch mechanism 38 and the laminating mechanism 48 may be adopted.
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(28) It is desirable that the thermoplastic elastic resin as the material of the elastic member 3 be a thermoplastic resin that exhibits rubber elasticity at room temperature; for example, an appropriate kind may be selected from among thermoplastic elastomers defined and classified in JIS K 6418:2007 (ISO 18064:2003). For example, a thermoplastic elastomer that elastically deforms in a temperature region of not more than approximately 100 degrees C. is used.
(29) Specific examples include an olefinic elastomer such as “VERSIFY” (trademark) of The Dow Chemical Company, a propylene elastomer such as “Vistamaxx” (trademark) of Exxon Mobil Corporation, and a styrene elastomer such as “Quintac” (trademark) of Zeon Corporation.
(30) The elastic composite sheet manufacturing device 10 is capable of easily manufacturing the elastic composite sheet 8 having desired characteristics. Moreover, the process of manufacturing the elastic member 3 from the elastic resin material that has a thermoplastic elastic resin as the main component and laminating it on the nonwoven fabrics 4 and 6 to complete the elastic composite sheet 8 can be continuously performed and it is unnecessary to prepare a preprocessed elastic member 3, so that the manufacturing cost can be reduced.
(31) The extension rate of the intermediate product 2 in the first section 80 can be adjusted by the feeding speed and discharge amount of the elastic resin material when it is discharged from the discharge mechanism 20 and the circumferential speed (the outside diameter, the number of rotations) of the cooling roller 30. By periodically changing the extension rate of the intermediate product 2, an elastic composite sheet can be manufactured in which the coefficient of elasticity of the elastic member 3 varies according to the position in the extension direction of the elastic member 3.
(32) The stretching rate of the elastic member 3 in the third section 84 can be adjusted by changing the difference in circumferential speed between the drawing roller 34 and the stretch roller 40. By periodically changing the circumferential speed of the stretch roller 40 and periodically changing the stretching rate of the elastic member 3 in the third section 84, an elastic composite sheet can be manufactured in which the stretching rate of the elastic member 3 varies according to the position in the stretching direction of the elastic member 3.
(33) When the discharge mechanism 20 forms the film-shape intermediate product 2 or a plurality of the linear-shape intermediate products 2, the conditions for cooling the intermediate product 2 such as the surface temperature and the thermal conductivity may be varied in the axial direction of the cooling roller 30. In this case, the elastic composite sheet 8 can be manufactured in which the coefficient of elasticity of the elastic member 3 varies according to the position in the width direction (a direction vertical to the flow direction and the thickness direction of the elastic composite sheet 8 in the manufacturing process) of the elastic composite sheet 8.
(34) When the elastic composite sheet 8 includes a plurality of linear-shape elastic members 3, characteristics such as the position of disposition, the coefficient of elasticity and the stretching rate can be adjusted for each elastic member 3 according to the shape, number and disposition of the discharge outlet of the discharge mechanism 20.
(35) Next, referring to
(36) <First modification> A structure may be adopted in which the laminating mechanism 48 of the elastic composite sheet manufacturing device 10 supplies, of the first nonwoven fabric 4 and the second nonwoven fabric 6, only the first nonwoven fabric 4 and the elastic member 3 is laminated on and bonded to the first nonwoven fabric 4. In this case, an elastic composite sheet having stretchability can also be manufactured.
(37) In this case, the manufacturing method of the elastic composite sheet does not include the sub step of the manufacturing method of the elastic composite sheet of the first embodiment.
(38) <Second embodiment> A second embodiment will be described with reference to
(39) As shown in
(40) As shown in
(41) As shown in
(42) Of the intermediate product 2, the end parts that are in contact with the both end regions 31a and 31b of the outer peripheral surface 31s of the first cooling roller 31 are cooled to the temperature region at which the elastic resin material elastically deforms, and hardened to exhibit elasticity. On the other hand, the central part that is in contact with the central region 31c of the outer peripheral surface 31s of the first cooling roller 31 remains in an extendable state because the temperature thereof is higher than the temperature region at which the elastic resin material elastically deforms.
(43) The second cooling roller 33 is structured so that the entire outer peripheral surface 33s has a temperature within the temperature region at which the elastic resin material elastically deforms. The speed (circumferential speed) V.sub.2 of the second cooling roller 33 is made higher than the speed (circumferential speed) V.sub.1 of the first cooling roller 31. Thereby, of an intermediate product 2x drawn from the first cooling roller 31, both end parts 2s and 2t having passed the both end regions 31a and 31b of the outer peripheral surface 31s of the first cooling roller 31 are stretched. On the other hand, of the intermediate product 2x drawn from the first cooling roller 31, a central part 2u having passed the central region 31c of the outer peripheral surface 31s of the first cooling roller 31 is extended between the first cooling roller 31 and the second cooling roller 33, and by coming into contact with the second cooling roller 33, the central part 2u is cooled to the temperature region at which the elastic resin material elastically deforms, and hardened to exhibit elasticity.
(44) When discharged from the second cooling roller 33, the intermediate product 2x becomes an elastic member 3x any part in the width direction (a direction vertical to the flow direction and the thickness direction of the intermediate product 2x in the manufacturing process) of which exhibits elasticity.
(45) The speed (circumferential speed) V.sub.3 of the drawing roller 34 is made higher than the speed (circumferential speed) V.sub.2 of the second cooling roller 33. Thereby, the elastic member 3x drawn from the second cooling roller 33 is stretched both in the both end parts 3a and 3b and in the central part 3c.
(46) The speed (circumferential speed) V.sub.4 of the stretch roller 40 is made higher than the speed (circumferential speed) V.sub.3 of the drawing roller 34. Thereby, the elastic member 3x drawn from the drawing roller 34 is stretched both in the both end parts 3a and 3b and in the central part 3c.
(47) As in the first embodiment, the elastic member 3x is laminated on the first and second nonwoven fabrics 4 and 6 by the laminating mechanism 48 to form a laminated body 7x. The laminated body 7x is supersonically bonded when passing between the stretch roller 40 and the horn 43 of the ultrasonic bonding device 42, whereby an elastic composite sheet 8x is formed in which the elastic member 3x and the first and second nonwoven fabrics 4 and 6 are intermittently bonded.
(48) The following Table 1 shows combinations of extension and stretching due to the speed differences among V.sub.1 to V.sub.4 regarding the both end parts 3a and 3b and the central part 3c of the elastic member 3x. Here, V.sub.0<V.sub.1<V.sub.2<V.sub.3.
(49) TABLE-US-00001 TABLE 1 V.sub.0 V.sub.1 V.sub.2 V.sub.3 Both ends Extension Stretching Stretching Center Extension Extension Stretching
(50) For example, the contraction force and the contraction amount in the flow direction of the elastic member 3x prototyped with V.sub.0:V.sub.1:V.sub.2:V.sub.3=100:150:200:300 are shown in the following Table 2. Compared with the central part 3c, the both end parts 3a and 3b of the elastic member 3x are high in contraction force and largely contract.
(51) TABLE-US-00002 TABLE 2 Contraction force Contraction amount Both ends 66% 50% Center 50% 66%
(52) That is, the elastic resin material extruded in the center in the width direction does not exhibit elasticity at the first cooling roller 31, and until coming into contact with the second cooling roller 33 on the downstream side, the elastic resin material is extended so that the thickness or the width is further reduced, whereby a region having a less contraction stress than the both end parts can be formed.
(53) By providing a plurality of cooling members (first and second cooling rollers 31 and 33) having different temperature conditions so that the intermediate products 2 and 2x of the heat-melted and discharged elastic resin material pass the plurality of cooling members (first and second cooling rollers 31 and 33) successively and cooling the intermediate products 2 and 2x in a plurality of steps, the elastic member 3x that varies in contraction characteristics along the width direction can be obtained. Moreover, it is easy to stabilize the quality of the elastic member 3x.
(54) The cooling member may have a shape other than the roller shape, such as an endless belt shape. Three or more cooling members may be used.
(55) <Third embodiment> A disposable wearing article 70 using the elastic composite sheet 8 or 8x manufactured according to the first embodiment or the second embodiment will be described with reference to
(56) As shown in
(57) In the case of a so-called shorts-type disposable wearing article, a pair of sides 72s of the front body portion 72 and a pair of sides 74s of the rear body portion 74 are previously bonded by heat sealing or the like.
(58) The elastic composite sheet 8 of the first embodiment can be used so that the elastic member 3 is disposed on the front body portion 72 and the rear body portion 74 of the disposable wearing article 70. In this case, it is easy to provide desired characteristics such as the stretching stress and the stretching rate according to the part where the elastic member 3 is used.
(59) The elastic composite sheet of the first embodiment including the film-shape elastic member may be used for the disposable wearing article. In this case, it is also easy to provide desired characteristics such as desired stretching stress and stretching rate according to the part where the film-shape elastic member is used.
(60) The elastic composite sheet 8x of the second embodiment is used, for example, so that the both end parts are disposed in the front body portion 72 and the rear body portion 74 of the disposable wearing article 70 and the central part is disposed in the crotch portion 76 and part of the front body portion 72 and the rear body portion 74. In this case, it is easy to provide desired characteristics such as desired stretching stress and stretching rate in the direction around the body and the direction around the legs.
(61) <Summary> As described above, an elastic composite sheet having desired characteristics can be easily manufactured, and furthermore, the manufacturing cost can be reduced.
(62) The present invention is not limited to the above-described embodiments and may be variously modified when carried out.
(63) For example, while the elastic composite sheet in which the elastic member and the nonwoven fabrics are laminated and bonded is shown as an example, a base material sheet other than a nonwoven fabric may be used to manufacture an elastic composite sheet.
(64) Moreover, two or more discharge mechanisms may be used. In this case, an elastic member may be formed by superposing intermediate products discharged from different discharge mechanisms one on another.
EXPLANATIONS OF LETTERS OR NUMERALS
(65) 2, 2x Intermediate product 3, 3x Elastic member 4 First nonwoven fabric (first base material sheet) 6 Second nonwoven fabric (second base material sheet) 8, 8x Elastic composite sheet 10, 10a Elastic composite sheet manufacturing device 20 Discharge mechanism 26, 28 Discharge outlet 30, 31, 33 Cooling roller (cooling member) 38 Stretch mechanism 40 Stretch roller 48 Laminating mechanism