JP4827597B2 - Elastic sheet and method for producing the same - Google Patents

Description

  The present invention relates to a method for producing an elastic sheet, a method for stretching a laminated sheet or a fiber sheet, and an elastic sheet.

  A method is known in which a sheet material having elastic stretchability and a substantially inelastic sheet material are partially bonded and then stretched to obtain a stretchable sheet material. For example, Patent Document 1 discloses a sheet-like elastic body in a relaxed state and a sheet-like base material that has the same extensibility as the elastic body but does not have stretch recovery properties in the length direction (MD). Specifically, after forming an elastic composite by discontinuous bonding in the width direction (CD), the elastic composite is stretched to the elongation limit within a range that does not cause the substrate to be cut or broken. A method for producing an elastic composite in which elongation is relaxed after permanent deformation of the material is described.

Japanese Patent Laid-Open No. 5-222601

  However, in the conventional method for producing a stretchable sheet as described above, depending on the degree of stretching, between the two partially joined sheet materials may be peeled off during stretching and the produced stretchable sheet There was a risk that the tensile strength would be insufficient, or the texture and appearance would deteriorate due to fluff and tearing. In order to prevent such inconvenience, it is conceivable to suppress the elongation rate during stretching, but in that case, it becomes difficult to obtain a highly stretchable sheet.

Accordingly, an object of the present invention is to provide a method for producing a stretchable sheet, which can produce a stretchable sheet having high stretchability and good texture and appearance.
Another object of the present invention is to provide a stretchable sheet which is rich in stretchability, is bulky, and has excellent cushioning properties (thickness recovery after being compressed in the thickness direction).

  The present invention provides a laminated sheet having an elastic layer having elastic elasticity and a substantially inelastic non-elastic fiber layer, in which the both layers are partially bonded, and a bonded portion between the two layers. The object is achieved by providing a method for producing a stretchable sheet that is stretched to a base point to obtain a stretchable sheet (hereinafter referred to as the present invention when referred to as the first invention).

  Further, the present invention provides a stretchable sheet by stretching a fiber sheet containing an elastic component and a substantially inelastic component and having a partial embossed part formed by embossing from the embossed part as a base point. The object is achieved by providing a method for producing an elastic sheet to be obtained (hereinafter referred to as this invention when referred to as the second invention).

  The present invention also includes a belt-like laminated sheet having an elastic layer having elastic elasticity and a substantially inelastic non-elastic fiber layer, and both layers are partially joined, or an elastic component. And a pair of concavo-convex rolls in which a large-diameter portion and a small-diameter portion are alternately formed in the axial length direction. The stretching step of inserting between a pair of concavo-convex rolls combined so that the large-diameter portion of one concavo-convex roll is loosely inserted between the large-diameter portions of the other concavo-convex roll, In the width direction of the laminated sheet or the fiber sheet, the position of the joint part or the embossed part between the two layers and the position of the large diameter part of the concave-convex roll are matched, and the width of the laminated sheet or the fiber sheet is adjusted. Stretchable, stretched in the direction There is provided a method of manufacturing.

Further, the present invention provides a laminated sheet having an elastic layer having elastic elasticity and a substantially inelastic non-elastic fiber layer, and both layers are partially bonded, and a bonded portion between the two layers. The present invention provides a method for stretching a laminated sheet that is stretched from the base point.
The present invention also relates to a method for stretching a fiber sheet, wherein a fiber sheet containing an elastic component and a substantially inelastic component and having an embossed portion partially formed by embossing is stretched based on the embossed portion. Is to provide.

  Further, the present invention includes an elastic layer having elastic stretchability and a substantially inelastic non-elastic fiber layer, and bonded portions where both layers are bonded are formed at a plurality of locations in the sheet stretching direction. The stretchable sheet has a ridge and a groove extending along a direction substantially orthogonal to the stretching direction on at least one surface of the stretchable sheet, and the bulge and the groove are A stretchable sheet is provided that is alternately formed in the stretching direction and is formed in plural, and in which the joint portion is located at least in the raised portion.

  Further, the present invention is an elastic sheet comprising an elastic component and a substantially inelastic component, wherein the partial embossed portions by embossing are formed at a plurality of locations in the sheet stretching direction, At least one surface of the elastic sheet has ridges and grooves extending along a direction substantially orthogonal to the extending direction, and the ridges and the grooves are alternately formed in the extending direction. And a plurality of each of which is formed, and the embossed portion is provided at least at the raised portion.

According to the method for producing an elastic sheet of the present invention, an elastic sheet having high elasticity and good texture and appearance can be efficiently produced.
According to the method for stretching a laminated sheet or fiber sheet of the present invention, the other portions can be efficiently elongated without destroying the joint portion or the embossed portion between the fiber layers.
The stretchable sheet of the present invention is rich in stretchability, is bulky, and has excellent cushioning properties (thickness recovery after being compressed in the thickness direction).

The present invention will be described below based on preferred embodiments with reference to the drawings.
In 1st Embodiment of this invention, as shown to Fig.3 (a) and FIG.3 (c), it is substantially inelastic respectively on both surfaces of the 1st fiber layer (elastic layer) 1 which has elastic elasticity. The second and third fiber layers (non-elastic fiber layers) 2 and 3 are laminated, and these are stretched to the laminated sheet 10A partially joined in a regular pattern.

  In the present embodiment, for example, a laminated sheet 10A obtained as shown in FIG. 1 can be used. That is, the elastic fiber 1 ′ formed by the fiber molding machine 22 on the fiber web (third fiber layer) 3 supplied from the first card machine 21 and continuously conveyed in one direction (flow direction, MD). And a layer (first fiber layer) 1 composed of elastic fibers 1 ′ is continuously formed on the fiber web 3. Furthermore, after continuously supplying the fiber web (second fiber layer) 2 supplied from the second card machine 23 to the laminated sheet 10B having the three-layer structure, the air-through system is used. An embossing device including an embossing roll 26 in which embossing convex portions are regularly arranged on the peripheral surface and an anvil roll 27 arranged so as to face the laminated sheet 10B subjected to the hot air treatment by the dryer 24. 25, heat embossing. Thereby, as shown in FIG. 2 and FIG. 3 (a) and FIG.3 (c), the lamination sheet 10A in which the junction part 4 was formed in the regular pattern is obtained.

In the manufacturing method of the laminated sheet 10A described above, hot air treatment by the dryer 24 is performed.
Although it is performed for the purpose of heat fusion between the elastic fiber and the non-elastic fiber and the entry of the fiber, such hot air treatment can be omitted.

A preferred configuration of the laminated sheet 10A will be described.
The first fiber layer (elastic layer) 1 can be stretched and has a property of contracting when released from the stretched force, and when contracted after 100% stretching in at least one direction parallel to the surface. The residual strain is preferably 20% or less, more preferably 10% or less when it is contracted after 100% elongation. These values are preferably satisfied in at least one of the MD direction and the CD direction, and more preferably satisfied in both directions. The maximum elongation is preferably 30 to 500%, particularly preferably 300 to 500%.

  The first fiber layer (elastic layer) 1 preferably includes elastic fibers made of an elastic material. Examples of the elastic material include a thermoplastic elastomer, rubber, ethylene / propylene copolymer, and the like. Among these, a thermoplastic elastomer is preferable because a fibrous elastic body can be formed relatively easily. Examples of the thermoplastic elastomer include polyurethane, styrene (SBS, SIS, SEBS, SEPS, etc.), olefin (copolymers such as ethylene, propylene, butene, etc.), vinyl chloride, and polyester. These can be used individually by 1 type or in combination of 2 or more types.

The content of elastic fibers made of an elastic material in the first fiber layer 1 is preferably 50 to 100% by weight, and particularly preferably 75 to 100% by weight. The elastic fiber resin of the first fiber layer may contain non-elastic resins such as polyethylene, polypropylene, polyester (PET or PBT), nylon, organic or inorganic pigments, and various additives (antioxidants, plasticizers, etc.). . Further, the first fiber layer can contain inelastic fibers, organic or inorganic pigments.
As an elastic layer, it can replace with what consists of a fiber layer, and a film-like thing, a net-like thing, etc. can also be used. As the film or net forming material, the above-mentioned various elastic materials can be used.

  The second and third fiber layers (inelastic fiber layers) 2 and 3 have extensibility, but are substantially inelastic. The stretchability here refers to the case where the constituent fibers themselves are stretched, and even if the constituent fibers themselves are not stretched, the two fibers that have been heat-sealed at the intersection of the fibers are separated from each other, or the fibers are thermally fused. Any of the cases where the three-dimensional structure formed by a plurality of fibers is structurally changed by wearing or the constituent fibers are broken and stretched as a fiber layer.

  Examples of the fibers constituting the inelastic fiber layer include fibers made of biodegradable resins such as polyethylene, polypropylene, polyester (PET and PBT), nylon, and polylactic acid. The fibers constituting the inelastic fiber layer may be short fibers or long fibers, and may be hydrophilic or water repellent. Moreover, a core-sheath type composite fiber, a split fiber, a modified cross-section fiber, a crimped fiber, a heat-shrinkable fiber, or the like can be used. These fibers can be used singly or in combination of two or more. In particular, short fibers tend to cause fluff due to stretching, but the use of this method is preferable in terms of high strength, prevention of fluffing, and good texture because the bonded portion is less likely to break.

  For example, as shown in FIG. 2 and FIGS. 3A and 3C, the joint portion 4 is formed discontinuously in both the flow direction (MD) of the laminated sheet 10A and its orthogonal direction (CD). It is preferable. In addition, the laminated sheet 10A has a second fiber layer and / or a third fiber layer, from the viewpoint of obtaining a stretchable nonwoven fabric (stretchable sheet) that is comfortable to the touch, and the bonding portion 4 forms a recess on the surface of the laminate sheet 10A. The other portions are preferably convex portions.

In 1st Embodiment, as above-mentioned, extending | stretching is given with respect to the laminated sheet 10A of a 3 layer structure.
In the first embodiment, as shown in FIGS. 1, 3 (b) and 3 (d), the laminated sheet 10 </ b> A has a large diameter portion 31, 32 and a small diameter portion (not shown) having an axial length. The laminated sheet 10A is stretched in a direction (CD) orthogonal to the flow direction by using a stretching apparatus 30 including a pair of concave and convex rolls 33 and 34 formed alternately in the direction.

The stretching device 30 is configured to be able to adjust the distance between the rolls 33 and 34 by displacing the pivotal support portion of one or both of the concave and convex rolls 33 and 34 by a known lifting mechanism.
In the method of the present embodiment, as shown in FIG. 1, FIG. 3 (b) and FIG. 3 (d), the large-diameter portion 31 of one concave / convex roll 33 is connected to the other concave / convex roll 33, 34. The rolls 34 are loosely inserted between the large-diameter portions 32, and the large-diameter portion 32 of the other concave-convex roll 34 is combined so that it is loosely inserted between the large-diameter portions 31 of the one concave-convex roll 33. , 34, the laminated sheet 10A is inserted, and the laminated sheet 10A is stretched.

In this stretching step, as shown in FIGS. 2 and 3A to 3D, the position of the joint 4 and the large-diameter portion 31 of the uneven rolls 33 and 34 in the width direction of the laminated sheet 10A. , 32 are made to coincide with each other. Specifically, as shown in FIG. 2, the laminated sheet 10 </ b> A is formed with a plurality of joint rows in which a plurality of joints 4 are formed in series and linearly in the MD direction. (10 are shown in FIG. 2). In FIG. 2, a joint portion R ₁ located on the leftmost side and other joint portions included in every other joint row R ₁ from there are The positions of the large-diameter portions 31 of the concave-convex roll 33 coincide with each other, and the joint portions included in each of the alternate joint row R ₂ from there, starting with the _second joint row R ₂ from the left. The position of the large-diameter portion 32 of the other uneven roll 34 is made to coincide. In FIG. 2, the ranges indicated by reference numerals 31 and 32 overlap the peripheral surfaces of the large-diameter portions 31 and 32 of each roll at a point in time when the laminated sheet 10 </ b> A is inserted between the two uneven rolls 33 and 34. The range is shown.

According to this embodiment, when the laminated sheet 10A passes between the concave and convex rolls 33 and 34, as shown in FIG. 3B and FIG. The large-diameter portions 31 and 32 overlap each other, while the regions between the large-diameter portions that do not overlap with the large-diameter portions 31 and 32, that is, the regions between the joint rows described above are actively stretched. In this way, by stretching the laminated sheet 10A from the joint 4 as a starting point, the joints 4 other than the joint are efficiently stretched while preventing the joint 4 from being broken (such as delamination between layers). Can be made. In addition, due to this stretching, the second and third fiber layers (non-elastic fiber layers) 2 and 3 undergo a change that does not recover even when the laminated sheet 10A contracts, and the change causes the second and third fiber layers. The degree to which the (non-elastic fiber layers) 2 and 3 hinder free expansion and contraction of the elastic fiber layer is greatly reduced.
Thereby, according to this embodiment, it is possible to efficiently produce a stretchable nonwoven fabric (stretchable sheet) that is highly stretchable, soft to the touch, and has a high strength and a good appearance with little tearing and fluffing. .

  As described above, the change that occurs in the second and third fiber layers (non-elastic fiber layers) 2 and 3 and that does not recover even when the laminated sheet 10A contracts may cause the constituent fibers to stretch unrecoverably or the fibers The two fibers that were heat-sealed at the intersection of each other may be separated, the three-dimensional structure formed by multiple fibers may be structurally changed or the constituent fibers may be torn due to heat-sealing of the fibers. Etc. However, from the viewpoint of obtaining a stretchable non-woven fabric (stretchable sheet) with a good touch, the constituent fibers are partially separated to such an extent that the two fibers that have been heat-sealed are not separated from each other or fuzzing is not severe. It is preferable to tear off.

4A and 4B show a cross section of the stretchable nonwoven fabric 10 obtained by the manufacturing method of the first embodiment. 4A is a cross section corresponding to the cross section taken along the line II in FIG. 2, and FIG. 4B is a cross section corresponding to the cross section taken along the line II-II in FIG.
5A is a schematic plan view showing a surface of the stretchable nonwoven fabric 10 on the non-elastic fiber layer 2 side, and FIG. 5B is a cross-sectional view taken along the line III-III in FIG. FIG.

As shown in FIG. 5 (b), the stretchable nonwoven fabric 10 has substantially inelastic second and third fiber layers (non-elasticity) on both surfaces of the first fiber layer (elastic layer) 1 having elastic stretchability. The elastic fiber layers 2 and 3 are laminated. And the junction parts 4 and 4 from which the 2nd fiber layer 2 to the 3rd fiber layer 3 were integrated in the thickness direction in the some place in the extending | stretching direction (D1 direction in the figure) of the elastic nonwoven fabric (elastic sheet) 10. -Is formed.
Here, the stretching direction refers to a laminated sheet in which both the elastic layer and the non-elastic fiber layer are partially bonded, or a partial embossed portion including an elastic component and a substantially non-elastic component. This is the direction in which the stretched fiber sheet is stretched to obtain a stretchable sheet, and refers to a direction parallel to the surface of the sheet. In the stretchable sheet, the stretching direction is the stretching direction, and when the stretching direction cannot be confirmed from the stretchable sheet, the maximum stretching direction of the stretching direction is taken as the stretching direction. The maximum expansion / contraction direction is the one direction when the elastic sheet expands / contracts in only one direction out of the directions parallel to the surface of the sheet, and a plurality of out of the directions parallel to the surface of the sheet When expanding and contracting in the direction, the direction perpendicular to the direction with the lowest elongation at the maximum strength point (maximum elongation) in the stretching direction in the tensile test is defined as the maximum stretching direction.
The stretchable nonwoven fabric 10 of the present embodiment is obtained by stretching the laminated sheet 10A described above in the width direction (CD direction), and the same direction as the width direction of the laminated sheet 10A has the most stretchability. Therefore, the same direction as the width direction of the laminated sheet 10A, in other words, the direction (CD) orthogonal to the machine direction (MD) at the time of manufacture is the stretching direction and the maximum stretching direction.

As shown in FIGS. 4A, 4B, 5A, and 5B, the stretchable nonwoven fabric 10 has a plurality of raised portions 12 and a plurality of groove portions 13 on both sides thereof. Have. And in any surface of the elastic nonwoven fabric 10, the protruding part 12 and the groove part 13 are respectively in the direction (D2 direction in the figure) substantially orthogonal to the extending direction (D1 direction in the figure) of the elastic nonwoven fabric 10. And extend alternately in the extending direction (D1 direction in the figure).
As described above, the ridges 12 and the grooves 13 are alternately formed in the extending direction on both surfaces of the stretchable nonwoven fabric 10. Thereby, the cross section of the stretchable nonwoven fabric 10 has a waveform shape microscopically. This corrugated shape is generated by stretching when the stretchable nonwoven fabric 10 is manufactured. This corrugated shape is produced as a result of imparting stretchability to the stretchable nonwoven fabric 10, and does not have a significant adverse effect on the texture itself of the nonwoven fabric 10, and a softer and better one can be obtained.

As shown in FIG. 5A, the raised portions 12 on each surface of the stretchable nonwoven fabric 10 as a whole extend along a direction (D2 direction in the drawing) substantially orthogonal to the stretching direction. A plurality of the joint portions 4 are intermittently formed in the longitudinal direction of the raised portion 12. The joint portion 4 is located at the approximate center in the width direction of the raised portion 12.
In the bulging portion 12, in the longitudinal direction, the substantially central portion 12 a between the bonding portion 4 and the bonding portion 4 is highest, while the bonding portion 4 and its periphery are relatively low, A small concave portion 12 b is formed in a part of the portion 12.
In the stretchable nonwoven fabric 10 of the present embodiment, a plurality of joint portions 4 are intermittently formed in the longitudinal direction of the groove portion 13, and the joint portion 4 is located at the approximate center in the width direction of the groove portion 13. ing.
Generation | occurrence | production of fluff can be prevented because the junction part 4 is formed in the protruding part 12. FIG.

  In the elastic sheet of this invention, it should just be formed in the place which is a protruding part seeing from the any one surface side of this elastic sheet. That is, even if the joint portion is formed at the groove portion when viewed from one surface side of the elastic sheet, if the groove portion is a raised portion when viewed from the other surface side, the joint portion is , A joint formed in the raised portion.

In the stretchable nonwoven fabric 10 of the present embodiment, the region between the joint portion row R ₁ located in the raised portion 12 and the joint portion row R ₂ located in the adjacent groove portion 13 can be stretched, while the raised portion. The joint row R ₁ located at 12 and the joint row R ₂ located in the groove 13 do not substantially expand or contract, or even if they expand or contract, the extent of expansion or contraction is lower than the region between the joint rows. ing. Here, the joint row R ₁ of the raised portions 12 is a band-shaped region that overlaps with the plurality of joined portions 4 of each raised portion 12 and has substantially the same width as the width of each joined portion 4. The joint portion row R ₂ of the groove portion 13 is a band-shaped region that overlaps with the plurality of joint portions 4 of each groove portion 13 and has substantially the same width as the width of each joint portion 4.

  The peripheral surface of the large-diameter portion of the uneven roll is preferably not sharp so as not to damage the laminated sheet 10A (fiber sheet in the second invention), as shown in FIGS. 3 (b) and 3 (d). Furthermore, it is preferable that the surface has a flat surface with a predetermined width. The width W (see FIG. 3B) of the distal end surface of the large diameter portion is preferably 0.3 to 1 mm, and is 0.7 to 2 times the dimension of the joint portion 4 in the CD direction, particularly 0.9. It is preferably -1.3 times.

  The pitch P between the large-diameter portions (see FIG. 3B) is preferably 0.7 to 2.5 mm, 1.2 to 5 times the dimension of the joint portion 4 in the CD direction, particularly 2 It is preferable to be 3 times. As a result, a cloth-like appearance can be obtained, and a material with a good texture can be obtained. Also, the pitch in the CD direction of the joint portions 4 in the laminated sheet 10A (the pitch between the joint portion rows R1 adjacent in the CD direction or the pitch between the joint portion rows R2 adjacent in the CD direction) P1 [see FIG. ] Is basically doubled to match the positional relationship with respect to the pitch P between the large-diameter portions, but is 1.7 times to 2.3 because of the elongation and neck-in of the laminated sheet 10A in the CD direction. The position can be matched within the double range. By setting the pitch P between the large diameter portions and the pitch P1 of the joint portions 4 to such a ratio, the portion having the joint portion row in the laminated sheet 10A can be stably positioned at a position in contact with the large diameter portion. Can be made. And the part which passes between large diameter parts in 10 A of lamination sheets is extended | stretched by high magnification compared with the part which contacts a large diameter part. In the laminated sheet 10A, the portion pressed against the large diameter portion of the uneven roll has a lower draw ratio than the portion passing between the large diameter portions, so the position of the portion having the joint row and the position of the large diameter portion are Difficult to shift in the stretching direction.

As a method of extending the laminated sheet 10A based on the joint 4 between the elastic layer and the non-elastic fiber layer, the position of the joint 4 and the large-diameter portions 31 and 32 of the concave and convex rolls as in the above-described embodiment. In addition to a method of matching the positions and positively stretching between the large diameter portions 31 and 32, a method described in JP-A-6-133998 can also be used.
In the method shown in FIGS. 3 (a) to 3 (d), the gap between the large diameter portion of one uneven roll and the small diameter portion of the other uneven roll is widened, and the large diameter portion Stretching is performed with a configuration in which the laminated sheet 10A is not sandwiched between the small-diameter portions, but stretching can be performed with a configuration in which the interval between the two is narrowed and the laminated sheet 10A is sandwiched.

  By the stretching process, the thickness of the laminated sheet 10A is preferably increased 1.1 times to 3 times, particularly 1.3 times to 2 times before and after the stretching process. As a result, the fibers of the non-elastic fiber layers 2 and 3 are plastically deformed and stretched to make the fibers thin. At the same time, the non-elastic fiber layers 2 and 3 become more bulky and have a good texture and good cushioning properties.

  If the thickness of the laminated sheet 10A before being stretched is thin, there is an advantage that the space for transporting and storing the roll raw material of the laminated sheet 10A can be reduced.

  Furthermore, it is preferable that the bending rigidity of the laminated sheet 10 </ b> A is changed to 30 to 80%, particularly 40 to 70% as compared with that before the stretching process by the stretching process. As a result, a soft nonwoven fabric with good drapability can be obtained. Moreover, since the bending rigidity of 10 A of laminated sheets before extending | stretching process is high, since it becomes difficult for a wrinkle to enter into laminated sheets 10A by a conveyance line, it is preferable. In addition, the laminated sheet 10 </ b> A is not easily wrinkled even during the stretching process, which is preferable because it is easy to process.

  The thickness and bending rigidity of the laminated sheet 10A before and after the stretching process are the elongation of the fibers used for the non-elastic fiber layers 2 and 3, the embossing pattern of the embossing rolls, the pitches of the concavo-convex rolls 33 and 34, the thicknesses of the tips, and the meshing. Can be controlled by quantity.

  The stretchable sheet of the present invention has a high stretchability and has a good texture and appearance, with 40% or more, preferably 70% or more, of the number of joints drawn from the joint. A high strength, bulky and excellent cushioning property can be obtained.

  In the second embodiment of the present invention, a single-layer fiber sheet that includes an elastic component and a substantially inelastic component and has a partial embossed portion formed by embossing is stretched.

As a fiber sheet in the second embodiment, (1) a core-sheath type composite fiber in which a core part is composed of an elastic component and a sheath part is composed of a substantially inelastic component, or an elastic component and substantially inelastic An embossed portion formed by embossing in the same pattern as in the first embodiment described above on a fiber web or a nonwoven fabric of various manufacturing methods, which is composed of side-by-side type or multi-partition type composite fibers comprising the above components (2) An embossed portion formed by embossing in a pattern similar to the joint portion in the first embodiment described above on a fiber web or a non-woven fabric of various manufacturing methods containing elastic fibers and non-elastic fibers in a mixed state Can be used. Specific examples of the fiber sheet include a fiber web obtained by a card method, a spun bond, a fiber web spun by a melt blown, a hydroentangled fiber web, a needle entangled fiber web, and a number of heat-sealed portions using a heat roll. The thing formed in the shape of a dot in visual observation can be mentioned.
As an elastic component, the constituent material of the elastic fiber mentioned above can be mentioned. Examples of the substantially inelastic component include the constituent materials of the inelastic fiber described above.

In the second embodiment, the fiber sheet is stretched based on the embossed portion. As the method, the fiber sheet may be stretched from the embossed portion as the base point in the same manner as the laminated sheet is stretched from the joint portion in the first embodiment. For example, in the first embodiment described above, the embossed portion and the concavo-convex roll are used instead of inserting the laminated sheet 10A having the three-layer structure into the concavo-convex roll by matching the position of the joining portion 4 and the large-diameter portion of the concavo-convex roll. A single-layer fiber sheet is inserted into the concavo-convex roll together with the position of the large-diameter portion.
By stretching the fiber sheet having the embossed portion from the embossed portion as a base point, it is possible to efficiently stretch the other portions while preventing the embossed portion from being damaged.
Further, similarly to the elastic nonwoven fabric 10 described above, a ridge and a groove extending along a direction substantially orthogonal to the stretching direction are formed on both surfaces of the obtained elastic sheet. A plurality of the groove portions are alternately formed in the extending direction. And the embossed part is located in those protruding parts and groove parts. The stretching process for the single-layer fiber sheet is also preferably performed under the same conditions as the stretching process for the laminated sheet 10A described above.

  The stretchable nonwoven fabric (stretchable sheet) obtained by the production method of the present invention can be used for various uses such as clothes, cleaning sheets, automobiles, furniture, bedding, etc. It is preferably used as a constituent material of absorbent articles such as sanitary napkins and disposable diapers. For example, it can be used as a sheet or the like for imparting elastic elasticity to the waist part, waist part, leg part or the like of a disposable diaper, and can also be used as a sheet or the like for forming a stretchable wing of a napkin. Moreover, even if it is another site | part, it can be used for the site | part etc. which want to provide a stretching property. When a stretchable nonwoven fabric having a structure in which an elastic layer and an inelastic fiber layer are laminated (two-layer or three-layer structure) is used in a place where the wearer's skin is touched, the non-elastic fiber layer is used on the wearer's skin. It is preferable to use it so that it may face to the side from the viewpoints of touch and prevention of stickiness. The method for stretching a laminated sheet or fiber sheet of the present invention is particularly preferably used in a method for producing a stretchable nonwoven fabric (stretchable sheet) as in the above-described embodiment, but can also be used for other purposes.

  The present invention is not limited to the embodiment. For example, the laminated sheet 10A used in the first embodiment has a three-layer structure, but the same applies to a case in which an inelastic fiber layer is laminated only on one surface side of the first fiber layer (elastic layer). It can also be used. In addition, the arrangement of the joint portion in the first invention and the embossed portion in the second invention may be formed in another pattern instead of the staggered pattern. The arrangement pattern of the joint portion in the laminated sheet and the embossed portion in the fiber sheet can be various patterns. For example, the above-described joint row extending in the MD direction of the pattern shown in FIG. Thus, the positions of the joint portions may be the same, or there may be three or more types of joint portion rows with different positions of the joint portions. When expanding and contracting in the CD direction, the joint portion may be continuous in the MD direction, and when expanding and contracting in the MD direction, the joint portion may be continuous in the CD direction. Furthermore, if the joint row is in the large diameter portion of the concavo-convex roll, there may be a joint between them.

  Further, the joint portion in the first invention may be formed by ultrasonic embossing, high-frequency embossing, adhesive, or the like instead of hot embossing. Further, the embossed portion in the second invention may also be formed by ultrasonic embossing, high frequency embossing or the like in addition to thermal embossing. Moreover, the planar view shape of the joint portion or the embossed portion may be an ellipse, a triangle, a rectangle, or the like other than a circle, or the joint portion or the embossed portion of these two or more shapes is a laminated sheet or fiber. It may be formed on a sheet.

Furthermore, in each embodiment mentioned above, although the lamination sheet or the fiber sheet was extended | stretched in CD direction of a flow direction, it can also be extended | stretched in MD direction.
For example, a stretching apparatus as shown in FIGS. The stretching apparatus shown in FIG. 6 includes a pair of concavo-convex plates 37 in which a plurality of ridges 36 extending in a direction orthogonal to the X direction are formed on opposing surfaces. It is configured to be displaceable using a cam mechanism so that the distance can be enlarged or reduced. In order to stretch the laminated sheet or fiber sheet, the MD direction of the laminated sheet or fiber sheet was made to coincide with the X direction, and the position of the joint part of the laminated sheet or the embossed part of the fiber sheet was made to coincide with the ridges of the uneven plate. In the state, both the concavo-convex plates are displaced from the separated state to the engaged state (the state shown in FIG. 6).

  The stretching apparatus shown in FIG. 7 includes a pair of caterpillars 38, and each has a ridge 36 similar to the ridge in the apparatus of FIG. By introducing a laminated sheet or a fiber sheet from the arrow direction in FIG. 7, the laminated sheet or the fiber sheet can be continuously stretched in the MD direction.

The stretching apparatus shown in FIG. 8 is a multi-stage gear type stretching apparatus, and is provided with stretching sections 39 combined with gears having ridges in multiple stages. The draw ratio is increased from the downstream stretched portion toward the upstream stretched portion.
6 to 8, the laminated sheet or the fiber sheet can be stretched in the MD direction based on the joint or the embossed portion.

In addition, the laminated sheet to be stretched can be effectively stretched even if it is a laminated sheet in which the elastic layer and the substantially inelastic layer are joined over the entire surface, and further joined partially, if there is a difference in joint strength. Is possible. Examples of full-surface bonding include those using adhesives such as hot melt, those fused by the heat of fusion during spinning, those fused to fibers and films by thermal lamination and hot air, needle punching and hydroentanglement Will raise the fiber intertwined. Examples of partial bonding include those using the heat embossing, ultrasonic embossing, and adhesive described above. What is necessary is just to perform an extending | stretching process on the joint part with high joint point intensity | strength.
In addition, the difference in the joint point density is, for example, when there is a joint part in which the elastic layer and the substantially non-elastic layer are entirely joined by hot melt, and further both are partially joined by heat sealing or the like. It means that the bonding pattern is different between the hot-melt bonding point and the bonding point by heat sealing or the like, or when the partial bonding is performed after the entire surface bonding, the bonding pattern is different.

  Moreover, the elastic sheet of this invention may have the protruding part and groove part in the elastic nonwoven fabric 10 mentioned above only on the single side | surface of a sheet | seat. Moreover, while the said junction part 4 is formed in the protruding part 12, the said junction part 4 may not be formed in the groove part 13. FIG. Further, the stretch direction of the stretchable sheet may be the longitudinal direction instead of the same width direction as the machine direction at the time of manufacture (conveying direction of the laminated sheet or the like as a raw material), and the width direction and the longitudinal direction The direction may be 45 degrees with respect to each other.

FIG. 1 is a schematic diagram showing a stretchable sheet manufacturing apparatus used in an embodiment of the stretchable sheet manufacturing method of the present invention. FIG. 2 is a plan view showing an example of a laminated sheet subjected to stretching in the present invention. 3 (a) to 3 (d) are schematic cross-sectional views in the CD direction of the laminated sheet shown in FIG. 2, and FIG. 3 (a) is a cross-sectional view taken along line II in FIG. b) is a cross section corresponding to FIG. 3A in a deformed state (stretched state) between the concavo-convex rolls, FIG. 3C is a cross section taken along the line II-II in FIG. (d) is a figure which shows the cross section corresponded to (c) of the state deform | transformed between the uneven | corrugated rolls (state extended). 4 (a) and 4 (b) are schematic diagrams showing stretchable nonwoven fabrics (stretchable sheets) obtained by stretching the laminated sheet shown in FIG. 2 in the CD direction, and FIG. FIG. 4B is a cross-sectional view corresponding to the cross section taken along the line II in FIG. 2, and FIG. 4B is a cross-sectional view corresponding to the cross section taken along the line II-II in FIG. 5 (a) and 5 (b) are diagrams showing an embodiment of the stretchable sheet of the present invention, and FIG. 5 (a) shows the stretchable nonwoven fabric (stretchable sheet) on the non-elastic fiber layer side. FIG. 5B is a cross-sectional view taken along the line III-III in FIG. FIG. 6 is a diagram illustrating an example of a stretching apparatus for stretching a laminated sheet or fiber sheet in the MD direction. FIG. 7 is a diagram illustrating another example of a stretching apparatus for stretching a laminated sheet or fiber sheet in the MD direction. FIG. 8 is a view showing still another example of a stretching apparatus for stretching a laminated sheet or fiber sheet in the MD direction.

Explanation of symbols

1 First fiber layer (elastic layer)
2 Second fiber layer (non-elastic fiber layer)
3 Third fiber layer (non-elastic fiber layer)
4 Embossed part (joint part)
10A Laminated sheet 10 Elastic nonwoven fabric (elastic sheet)
12 ridge 13 groove

Claims (2)

A belt-like laminated sheet having an elastic layer having elastic elasticity and a substantially inelastic non-elastic fiber layer, and both layers are partially joined, or an elastic component and a substantially inelastic component A belt-like fiber sheet in which a partial embossed part is formed by embossing,
A pair of concavo-convex rolls in which a large-diameter portion and a small-diameter portion are alternately formed in the axial length direction, and the large-diameter portion of one concavo-convex roll is combined so as to be loosely inserted between the large-diameter portions of the other concavo-convex roll. Comprising a stretching step inserted between a pair of uneven rolls,
In the stretching step, in the width direction of the laminated sheet or the fiber sheet, the position of the joint part or the embossed part between the two layers and the position of the large diameter part of the concavo-convex roll are made to coincide with each other. Or the manufacturing method of the elastic sheet which extends | stretches the said fiber sheet in the width direction. A belt-like laminated sheet having an elastic layer having elastic elasticity and a substantially inelastic non-elastic fiber layer, and both layers are partially joined, or an elastic component and a substantially inelastic component A belt-like fiber sheet in which a partial embossed part is formed by embossing,
A pair of concavo-convex rolls in which a large-diameter portion and a small-diameter portion are alternately formed in the axial length direction, and the large-diameter portion of one concavo-convex roll is combined so as to be loosely inserted between the large-diameter portions of the other concavo-convex roll. Comprising a stretching step inserted between a pair of uneven rolls,
In the stretching step, the position of the joint portion or the embossed portion between the two layers in the longitudinal direction of the laminated sheet or the fiber sheet, or the direction of 45 degrees with respect to the width direction and the longitudinal direction, respectively, and unevenness A method for producing an elastic sheet, wherein the laminated sheet or the fiber sheet is stretched in the longitudinal direction, or in the direction of 45 degrees with respect to the width direction and the longitudinal direction, respectively, by matching the position of the large diameter portion of the roll. .

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