A method of manufacturing an elastic composite sheet

Abstract

This invention provides a method for manufacturing an elastic composite sheet, comprising the following steps: a sheet bonding process: bonding and fixing an outer sheet extending along the flow direction with a first intermediate sheet and a second intermediate sheet located on both sides of the flow centerline, thereby forming a first joint between the outer sheet and the first intermediate sheet, and a second joint between the outer sheet and the second intermediate sheet, thus forming the elastic composite semi-finished product; an elastic material bonding process: bonding an elastic material between a first inner sheet and the first intermediate sheet of the elastic composite semi-finished product on one side of the flow centerline, and bonding an elastic material between a second inner sheet and the second intermediate sheet of the elastic composite semi-finished product on the other side of the flow centerline, thereby forming the elastic composite sheet. This invention avoids the possibility of the elastic material melting during the sheet bonding process and the possibility of adhesive penetrating into the ultrasonic device used in the sheet bonding process.

Description

Technical Field

[0001] This invention relates to the field of disposable hygiene product manufacturing equipment technology, and more particularly to baby pull-up diapers, adult pull-up diapers, and women's sanitary trousers, especially to a method for manufacturing an elastic composite sheet. Background Technology

[0002] Disposable hygiene products, such as pull-up diapers, typically consist of an outer cover and an inner sheet within the outer cover. The outer cover is an elastic composite sheet composed of an outer sheet, an inner sheet, and an elastic material sandwiched between the outer and inner sheets. To ensure the elastic composite sheet is soft, comfortable, and has regular folds that create breathable channels, a specific sheet-bonding process is usually used to fix the sheets together. The most common elastic materials are spandex (also known as elastic bands) or stretch membranes, or composite materials combining spandex and stretch membranes. Taking spandex as an example, the bonding process usually involves melting the sheets with heat to fix them. For example, ultrasonic devices use high-frequency vibrations to generate heat and fuse materials. However, this process usually occurs after the spandex has already been bonded between the outer and inner sheets. Therefore, the spandex between the outer and inner sheets may be melted by the ultrasonic device, reducing the elasticity of the composite sheet and lowering the quality of the disposable hygiene product.

[0003] On the other hand, before the spandex filament is laminated between the outer and inner sheets, adhesive is usually applied to either the spandex filament or the outer or inner sheet. Therefore, in the subsequent sheet bonding process, there is a risk that the adhesive may seep from the sheet onto the bottom roller of the ultrasonic device, which requires regular cleaning of the bottom roller of the ultrasonic device, greatly reducing the production efficiency of disposable hygiene products.

[0004] Because the outer covering layer is simply made of two layers of non-woven fabric sandwiching several spandex filaments bonded together with adhesive, the use of adhesive reduces the softness and comfort of the outer covering layer. Furthermore, in a shrunken state, its appearance is characterized by irregular large and small wrinkles, resulting in a poor visual appeal. Therefore, a new process needs to be developed to solve the problems of elastic material melting and adhesive seeping into the sheet bonding process equipment, while also maintaining the softness, comfort, and aesthetic appeal of the elastic composite sheet. Summary of the Invention

[0005] This invention provides an apparatus and method for manufacturing elastic composite sheets, which solves the technical problems of elastic material melting and adhesive penetrating into the apparatus of the sheet bonding process in the elastic composite sheet formed by the multi-layer sheet of the outer covering layer of disposable hygiene products, and the poor softness and comfort and unsatisfactory appearance of the elastic composite sheet.

[0006] The technical solution provided by this invention is as follows:

[0007] This invention provides a method for manufacturing an elastic composite sheet for producing an elastic composite sheet for the outer covering layer of disposable diapers. The manufacturing method includes the following steps:

[0008] Pre-processing steps for elastic composite semi-finished products: used to process and form elastic composite semi-finished products, including a first supply step and a second supply step arranged in parallel in the process, and a sheet bonding step located downstream of the first supply step and the second supply step;

[0009] First feeding process: After unwinding the outer sheet, it is continuously fed to the sheet bonding process;

[0010] Second supply process: The first intermediate sheet and the second intermediate sheet, which are parallel to each other and perpendicular to the process direction, are continuously conveyed to the sheet joining process along the process direction, wherein the first intermediate sheet is located on one side of the process center line and the second intermediate sheet is located on the other side of the process center line.

[0011] Sheet bonding process: The outer sheet extending along the flow direction is bonded and fixed to the first intermediate sheet and the second intermediate sheet located on both sides of the flow centerline, respectively, to form a first bonding portion between the outer sheet and the first intermediate sheet, and a second bonding portion between the outer sheet and the second intermediate sheet, thereby forming the elastic composite semi-finished product; wherein, when viewed from the outer sheet towards the first intermediate sheet and the second intermediate sheet, the outer sheet can simultaneously and completely cover the first intermediate sheet and the second intermediate sheet.

[0012] Among them, the process centerline is the baseline for the process design of disposable diapers in the manufacturing equipment for disposable diapers;

[0013] Elastic material composite supply process: includes a third supply process, a fourth supply process and an elastic material supply process arranged in parallel along the process flow; wherein, the elastic material supply process is located between the third supply process and the fourth supply process;

[0014] The third supply process: The first inner layer sheet and the second inner layer sheet, which are parallel to each other and perpendicular to the flow direction, are continuously conveyed to the downstream side along the flow direction. The first inner layer sheet is located on one side of the flow center line, and the second inner layer sheet is located on the other side of the flow center line.

[0015] Fourth supply process: The elastic composite semi-finished product is continuously conveyed to the downstream side along the flow direction;

[0016] Elastic material supply process: Continuously conveying multiple elastic materials along the flow direction;

[0017] Along the direction perpendicular to the process flow, the first inner layer sheet corresponds to the first intermediate sheet; the second inner layer sheet corresponds to the second intermediate sheet; and the first inner layer sheet and the first intermediate sheet are located on one side of the process centerline, while the second inner layer sheet and the second intermediate sheet are located on the other side of the process centerline.

[0018] Adhesive application process: Apply adhesive to the surface of each elastic material;

[0019] Elastic material composite process: On one side of the process centerline, elastic material extending along the process direction is composited between the first inner layer sheet and the first intermediate sheet of the elastic composite semi-finished product, and on the other side of the process centerline, elastic material extending along the process direction is composited between the second inner layer sheet and the second intermediate sheet of the elastic composite semi-finished product, thereby forming the elastic composite sheet.

[0020] In the first supply process, the supply speed is faster than that in the second supply process, so that the outer sheet is stretched.

[0021] In a preferred embodiment, the supply speed in the first supply step and the supply speed in the second supply step are adjusted respectively, and the supply speed in the first supply step is 1%-15% faster than the supply speed in the second supply step.

[0022] In a preferred embodiment, the first intermediate sheet and the second intermediate sheet have the same elongation and are both greater than the elongation of the outer sheet.

[0023] In a preferred embodiment, the elongation of the first intermediate sheet and the second intermediate sheet is 5%-15% greater than that of the outer sheet.

[0024] In a preferred embodiment, the fourth supply step is faster than the third supply step.

[0025] In a preferred embodiment, the sheet bonding process includes an ultrasonic device, which includes a first ultrasonic welding head, a second ultrasonic welding head, and an ultrasonic bottom roller. The first ultrasonic welding head and the second ultrasonic welding head are arranged parallel to each other in the axial direction and are simultaneously arranged opposite to the ultrasonic bottom roller.

[0026] In a preferred embodiment, the circumferential surface of the ultrasonic bottom roller is provided with a plurality of axially extending and arranged joint pattern portions.

[0027] The joining patterned portion includes a connected base and a protrusion, the base and the protrusion are spaced apart, and the protrusion is higher than the base. The surface of the protrusion is provided with a patterned design. The protrusion is welded to the first ultrasonic welding head and the second ultrasonic welding head to form the first joining portion and the second joining portion of the elastic composite semi-finished product.

[0028] In a preferred embodiment, the elastic material composite process includes a clamping composite roller, which includes a drive roller and a clamping roller disposed opposite each other.

[0029] The drive roller and the clamping roller clamp and drive the first inner layer sheet, the first intermediate sheet of the elastic composite semi-finished product, and the elastic material disposed between the first inner layer sheet and the first intermediate sheet of the elastic composite semi-finished product on one side of the process center line.

[0030] Simultaneously, the drive roller and the clamping roller clamp and drive the second inner layer sheet, the second intermediate sheet of the elastic composite semi-finished product, and the elastic material disposed between the second inner layer sheet and the second intermediate sheet of the elastic composite semi-finished product on the other side of the process centerline.

[0031] In a preferred embodiment, the first feeding process includes a first free roller disposed on the flow path for guiding the outer sheet;

[0032] The second supply process includes a second free roller disposed in the flow path to guide the first inner sheet and the second inner sheet;

[0033] The third supply process includes a third free roller disposed in the flow path to guide the first inner sheet and the second inner sheet;

[0034] The fourth supply process includes a fourth free roller disposed on the flow path to guide the elastic composite semi-finished product.

[0035] In a preferred embodiment, the elastic material supply process includes guide wheels disposed on the flow path for guiding the elastic material.

[0036] In a preferred embodiment, the elastic material supply process further includes a plurality of tension sensors, wherein each tension sensor corresponds to one elastic material.

[0037] In a preferred embodiment, the adhesive application process includes an adhesive application unit, with the elastic composite semi-finished product or the first inner layer sheet and the second inner layer sheet disposed below the adhesive application unit.

[0038] In a preferred embodiment, the manufacturing method further includes an elastic material cutting process disposed downstream of the elastic material composite process, the elastic material cutting process including an elastic material cutting unit;

[0039] The elastic material cutting unit is used to cut the elastic material between the first inner layer sheet and the first intermediate sheet in the position area corresponding to the composite inner sheet of the outer covering layer of the disposable diaper to form a first elastic weakening area.

[0040] And the elastic material between the second inner sheet and the second intermediate sheet is cut to form a second elastic weakening zone;

[0041] The inner pad of the disposable diaper is located inside the outer covering layer.

[0042] In a preferred embodiment, the manufacturing method further includes an output process disposed downstream of the elastic material cutting process, the output process including an output roller.

[0043] The above-described technical solution of the present invention has at least the following beneficial effects compared with the prior art:

[0044] This invention provides a method for manufacturing an elastic composite sheet. A first intermediate sheet located on one side of the process centerline perpendicular to the process direction and a second intermediate sheet located on the other side of the process centerline are first bonded to an outer sheet without adhesive. This forms a first joint between the outer sheet and the first intermediate sheet, and a second joint between the outer sheet and the second intermediate sheet, thereby forming an elastic composite semi-finished product. Since there is no elastic material between the first intermediate sheet, the second intermediate sheet, and the outer sheet, and it is merely a composite of sheets, there are no issues such as the elastic material melting during the sheet bonding process or adhesive seeping into the sheet bonding apparatus.

[0045] The elastic composite semi-finished product formed after the sheet bonding process is then combined with multiple elastic materials, a first inner layer sheet located on one side of the process centerline perpendicular to the process direction, and a second inner layer sheet located on the other side of the process centerline. Adhesive is applied only to the elastic materials to fix the elastic materials between the first inner layer sheet and the elastic composite semi-finished product, and between the second inner layer sheet and the elastic composite semi-finished product, thereby forming an elastic composite sheet.

[0046] This invention provides a method for manufacturing an elastic composite sheet. The method involves first joining two sheets together, followed by applying adhesive to the elastic material, resulting in a three-layer composite structure. This process achieves adhesive-free bonding, eliminating the possibility of the elastic material melting or adhesive seepage. Furthermore, since adhesive is applied only to the elastic material, rather than over a large area of ​​the sheet, the elastic composite sheet does not harden. The resulting semi-finished elastic composite sheet is soft and comfortable. The first and second joints create regular wrinkles, forming breathable channels and enhancing the aesthetic appeal.

[0047] This invention provides a method for manufacturing an elastic composite sheet. In the pre-processing step of the elastic composite semi-finished product, the supply speeds in the first and second supply steps are adjusted respectively, so that the supply speed in the first supply step is faster than that in the second supply step, causing the outer sheet to elongate and form wrinkles. These wrinkles provide the outer sheet with stretching space. Furthermore, the elongation rates of the first and second intermediate sheets are set to be greater than that of the outer sheet. Since the first and second intermediate sheets are positioned in the middle, this ensures that while the outer sheet has sufficient stretching space, the first and second intermediate sheets, due to their larger elongation rates, can be stretched. This achieves the prerequisite for producing an elastic composite sheet from the pre-finished elastic composite material. During lamination, the wrinkles are more pronounced, resulting in a more obvious, aesthetically pleasing, and elastic elastic composite sheet in its free state. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a schematic diagram of the structure of the disposable diaper manufactured according to the present invention in its unfolded state.

[0050] Figure 2 yes Figure 1 A cross-sectional view along the U-U direction.

[0051] Figure 3 yes Figure 1 A cross-sectional view along the VV direction.

[0052] Figure 4 This is a schematic flowchart illustrating a method for manufacturing an elastic composite sheet according to an embodiment of the present invention.

[0053] Figure 5 This is a schematic diagram of the ultrasonic device used in the sheet bonding process of the present invention.

[0054] Figure 6 This is a schematic diagram showing the circumferential unfolding of the ultrasonic bottom roller of the present invention.

[0055] Figure 7 yes Figure 6 A cross-sectional view along the RR direction.

[0056] Figure 8 This is a schematic diagram of the first and second supply processes of the present invention.

[0057] Figure 9 This is a schematic diagram of the sheet bonding process of the present invention.

[0058] Figure 10 This is a schematic diagram of the elastic material composite supply process, the adhesive application process, and the elastic material composite process of the present invention.

[0059] Figure 11 This is a schematic diagram (top view) of the elastic material cutting process of the present invention. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0061] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising,” “including,” or “including,” and similar terms mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or “connected,” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0062] It should be noted that the terms "up", "down", "left", "right", "front", and "back" used in this invention are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0063] like Figure 1 The diagram shown is a structural schematic of the disposable diaper manufactured according to the present invention in its unfolded state. Figure 2 As shown Figure 1 Cross-sectional view along the U-U direction. Figure 3 for Figure 1 Cross-sectional view in the VV direction. Figure 3 A schematic diagram of the elastic material in its contracted state is shown. The disposable diaper S has mutually orthogonal length, width, and thickness directions. To maintain alignment with the manufacturing equipment, the width direction of the disposable diaper S corresponds to the width direction of the manufacturing equipment, and the length direction corresponds to the flow direction of the manufacturing equipment.

[0064] The disposable diaper S includes an outer covering layer S1 and an inner sheet S2 disposed inside the outer covering layer S1. The inner sheet S2 is the absorbent core structure that mainly absorbs excrement. The outer covering layer S1 is an elastic composite sheet with an abdominal side S11 corresponding to the human abdomen and a buttock side S12 corresponding to the human buttocks.

[0065] On the abdominal side S11, viewed from the non-skin side towards the skin side along the thickness direction, it includes an outer sheet W1, a first intermediate sheet W21, an elastic material T, and a first inner sheet W31. The elastic material T extends along its length and is disposed between the first intermediate sheet W21 and the first inner sheet W31. The first intermediate sheet W21, the first inner sheet W31, and the outer sheet W1 can all be non-woven materials, specifically anti-stick non-woven fabric or heat-sealing non-woven fabric, etc. In this embodiment, the elastic material T is spandex filament (elastic band), and there are multiple elastic materials T; the specific number and position can be set according to the product of the disposable diaper S.

[0066] To avoid the problem of the elastic material T being melted and its elasticity being destroyed due to heat during the process of melting the sheets to join the first intermediate sheet W21, the first inner sheet W31, and the outer sheet W1, the outer sheet W1 and the first intermediate sheet W21 are first joined together to form a plurality of first joints F'. Then, the elastic material T is composited between the first intermediate sheet W21 and the first inner sheet W31, so that the elastic material T is disposed between the first intermediate sheet W21 and the first inner sheet W31 along the length direction.

[0067] like Figure 3As shown, on the abdominal side S11, the elastic composite sheet, when in a contracted state, is bonded between the first intermediate sheet W21 and the first inner sheet W31, resulting in irregular small folds on both sides of the elastic material T. The outer sheet W1, using a sheet bonding process, forms a first joint F' with the first intermediate sheet W21. Because the first joint F' has a regular floral pattern, the outer sheet W1 forms regular large folds on its outer side (non-skin side). The formation of these folds enhances the aesthetics and softness of the elastic composite sheet. Notably, the first joint F' only bonds between the outer sheet W1 and the first intermediate sheet W21, and does not bond with the elastic material T.

[0068] Similarly, on the buttock side S12, viewed from the non-skin side towards the skin side along the thickness direction, it includes an outer sheet W1, a second intermediate sheet W22, an elastic material T, and a second inner sheet W32, wherein the elastic material T extends along the length direction and is disposed between the second intermediate sheet W22 and the second inner sheet W32. The second intermediate sheet W22 and the second inner sheet W32 can be nonwoven materials, specifically, they can be non-stick nonwoven fabric or heat-sealing nonwoven fabric, etc.

[0069] To avoid the problem of the elastic material T being melted and its elasticity being destroyed due to heat during the process of melting the sheets to join the second intermediate sheet W22, the second inner sheet W32, and the outer sheet W1, the outer sheet W1 and the second intermediate sheet W22 are first joined together to form a second composite semi-finished product with multiple second joints F". Then, the elastic material T is composited between the second intermediate sheet W22 and the second inner sheet W32, so that the elastic material T is disposed between the second intermediate sheet W22 and the second inner sheet W32 along the length direction.

[0070] The elastic composite sheet in the buttocks side (S12 elastic material T) is in the same state of contraction as the abdominal side (S11 elastic material T), so it will not be described again.

[0071] The present invention discloses a method for manufacturing an elastic composite sheet, which is used to manufacture an elastic composite sheet for the outer covering layer S1 of a disposable diaper S.

[0072] like Figure 4 The diagram shown is a flowchart of a method for manufacturing an elastic composite sheet according to an embodiment of the present invention. The flow direction of the method for manufacturing an elastic composite sheet of the present invention corresponds to the length direction of a disposable diaper S, and the direction perpendicular to the flow direction corresponds to the width direction of the disposable diaper S.

[0073] According to an embodiment of the present invention, a method for manufacturing an elastic composite sheet is provided for manufacturing an elastic composite sheet for the outer covering layer S1 of a disposable diaper S.

[0074] A method for manufacturing an elastic composite sheet includes the following steps:

[0075] Pre-processing step A1 for elastic composite semi-finished products:

[0076] The elastic composite semi-finished product pre-processing process A1 is used to process and form the elastic composite semi-finished product, including a first supply process A11 and a second supply process A12 arranged in parallel in the process flow, and a sheet bonding process A13 located downstream of the first supply process A11 and the second supply process A12.

[0077] First supply process A11:

[0078] Combination Figure 4 and Figure 8 The first supply process A11 unwinds the outer sheet W1 and continuously feeds it to the sheet bonding process A13.

[0079] Specifically, the first supply process A11 includes a first supply unit G1, which includes a first free roller G11 disposed on the flow path for guiding the outer sheet W1. That is, the first supply process A11 includes a first free roller G11 disposed on the flow path for guiding the outer sheet W1.

[0080] After the outer sheet W1 is unwound, it is continuously conveyed and the first supply unit G1 continuously conveys the outer sheet W1 to the sheet bonding process A13.

[0081] Second supply process A12:

[0082] Combination Figure 4 and Figure 8 The second supply process A12 continuously feeds the first intermediate sheet W21 and the second intermediate sheet W22, which are parallel to each other perpendicular to the process direction, to the sheet joining process A13 along the process direction. The first intermediate sheet W21 is located on one side of the process center line L, and the second intermediate sheet W22 is located on the other side of the process center line L.

[0083] Specifically, the second supply process A12 includes a second supply unit G2, which includes a second free roller G21 disposed in the flow path for guiding the first intermediate sheet W21 and the second intermediate sheet W22. That is, the second supply process A12 includes the second free roller G21 disposed in the flow path for guiding the first intermediate sheet W21 and the second intermediate sheet W22.

[0084] After the first intermediate sheet W21 and the second intermediate sheet W22 are unwound, they are continuously conveyed. The second supply unit G2 continuously conveys the first intermediate sheet W21 and the second intermediate sheet W22, which are parallel to each other in the process direction, to the sheet bonding process A13.

[0085] The direction perpendicular to the flow path mentioned here refers to the width direction, which corresponds to the width direction of the disposable diaper S.

[0086] In a preferred embodiment, the first intermediate sheet W21 and the second intermediate sheet W22 are equidistant from the process centerline L. The process centerline L is the baseline used in the process design for manufacturing disposable diapers in the disposable diaper manufacturing equipment.

[0087] According to an embodiment of the present invention, the supply speed in the first supply step A11 is faster than the supply speed in the second supply step A12, so as to elongate the outer sheet W1 and form folds. These folds provide it with a stretching space, i.e., the height of the folds is the length that can be stretched. If the sheet W1 is not stretched, it will cause the material to break during stretching. In a preferred embodiment, the supply speed in the first supply step A11 is 1%-15% faster than the supply speed in the second supply step A12. The supply speeds in the first supply step A11 and the second supply step A12 are adjusted independently, for example, by setting their own drive rollers (not shown in the figure) to achieve the difference between the two supply speeds, and are adjusted in real time.

[0088] According to an embodiment of the present invention, the elongation rates of the first intermediate sheet W21 and the second intermediate sheet W22 are the same and simultaneously greater than the elongation rate of the outer sheet W1. The elongation rates of the first intermediate sheet W21 and the second intermediate sheet W22 are 5%-15% greater than the elongation rate of the outer sheet W1. Since the first intermediate sheet W21 and the second intermediate sheet W22 are located in the middle, setting the elongation rates of the first intermediate sheet W21 and the second intermediate sheet W22 to be greater than the elongation rate of the outer sheet W1 ensures that the outer sheet W1 has the elongation space when stretched, while the first intermediate sheet W21 and the second intermediate sheet W22, due to their relatively large elongation rates, can be stretched. This achieves the prerequisite conditions for the production of elastic composite sheets in the elastic composite semi-finished product, thereby achieving the prerequisite conditions for the subsequent molding of elastic composite semi-finished product W' to produce elastic composite sheets W. This results in the composite elastic composite sheet having more obvious wrinkles, a more beautiful appearance, better molding effect, and better elasticity in its free state. The outer sheet W1 is made of hot-air nonwoven fabric or spunbond nonwoven fabric, preferably hot-air nonwoven fabric. The outer sheet W1, the first intermediate sheet W21 and the second intermediate sheet W22 are materials with certain elastic shrinkage properties, so that the composite material formed after the outer sheet W1, the first intermediate sheet W21 and the second intermediate sheet W22 are relatively flat. The composite material is further compounded with the subsequent elastic material T and the first inner sheet W31 and the second inner sheet W32 under the tensile state, which also ensures the composite effect.

[0089] Sheet bonding process A13:

[0090] Combination Figure 4 , Figure 8 and Figure 9 In the sheet joining process A13, the outer sheet W1 extending along the flow direction is joined and fixed with the first intermediate sheet W21 and the second intermediate sheet W22 located on both sides of the flow center line L, so as to form a first joint F' between the outer sheet W1 and the first intermediate sheet W21, and a second joint F'" between the outer sheet W1 and the second intermediate sheet W22, thereby forming the elastic composite semi-finished product W'.

[0091] When viewed from the outer sheet W1 towards the first intermediate sheet W21 and the second intermediate sheet W22, the outer sheet W1 can simultaneously and completely cover both the first intermediate sheet W21 and the second intermediate sheet W22.

[0092] The process centerline L serves as the baseline for the process design of disposable diapers in the manufacturing equipment.

[0093] Specifically, the sheet joining process A13 is arranged downstream of the first supply unit G1 and the second supply unit G2. The sheet joining process A13 joins and fixes the outer sheet W1 extending along the flow direction with the first intermediate sheet W21 and the second intermediate sheet W22 located on both sides of the flow centerline L, thereby forming a first joint F' between the outer sheet W1 and the first intermediate sheet W21, and a second joint F'" between the outer sheet W1 and the second intermediate sheet W22, thus forming the elastic composite semi-finished product W'.

[0094] Sheet bonding process A13 includes ultrasonic device 2, bonding Figures 5 to 7 The ultrasonic device 2 includes a first ultrasonic welding head 22, a second ultrasonic welding head 23, and an ultrasonic bottom roller 21. The first ultrasonic welding head 22 and the second ultrasonic welding head 23 are arranged parallel to each other in the axial direction and are simultaneously arranged opposite to the ultrasonic bottom roller 21.

[0095] The ultrasonic bottom roller 21 has a plurality of axially extending joining pattern portions 211 spaced apart on its circumferential surface. Each joining pattern portion 211 includes a connected base portion 2111 and a protrusion portion 2112, which are spaced apart, and the protrusion portion 2112 is higher than the base portion 2111. The surface of the protrusion portion 2112 is provided with a pattern, and the protrusion portion 2112 is welded to the first ultrasonic welding head 22 and the second ultrasonic welding head 23 to form the first joining portion F' and the second joining portion F of the elastic composite semi-finished product W'.

[0096] Elastic material composite supply process A2:

[0097] The elastic material composite supply process A2 includes a third supply process A21, a fourth supply process A22, and an elastic material supply process A23, which are arranged in parallel along the process flow. The elastic material supply process A23 is located between the third supply process A21 and the fourth supply process A22.

[0098] Third supply process A21:

[0099] Combination Figure 4 and Figure 10 The third supply process A21 continuously transports the first inner layer sheet W31 and the second inner layer sheet W32, which are parallel to each other in the process direction, to the downstream side along the process direction. The first inner layer sheet W31 is located on one side of the process center line L, and the second inner layer sheet W32 is located on the other side of the process center line L.

[0100] Specifically, the third supply process A21 includes a third supply unit G3, which includes a third free roller G31 disposed in the flow path for guiding the first inner layer sheet W31 and the second inner layer sheet W32. That is, the third supply process A31 includes a third free roller G31 disposed in the flow path for guiding the first inner layer sheet W31 and the second inner layer sheet W32.

[0101] After the first inner layer sheet W31 and the second inner layer sheet W32 are unwound, they are continuously conveyed. The third supply unit G3 continuously conveys the first inner layer sheet W31 and the second inner layer sheet W32, which are parallel to each other in the process direction, to the elastic material composite process A4.

[0102] Fourth supply process A22:

[0103] Combination Figure 4 and Figure 10 The fourth supply process A22 continuously transports the elastic composite semi-finished product W' to the downstream side along the flow direction.

[0104] Specifically, the fourth supply process A22 includes a fourth supply unit G4, which includes a fourth free roller G41 disposed on the flow path for guiding the elastic composite semi-finished product W'. That is, the fourth supply process A32 includes the fourth free roller G41 disposed on the flow path for guiding the elastic composite semi-finished product W'. The elastic composite semi-finished product W' is continuously conveyed to the elastic material composite process A4 using the fourth supply unit G4.

[0105] According to an embodiment of the present invention, the supply speed of the fourth supply process A22 is faster than that of the third supply process A21, so that the outer sheet W1 in the elastic composite semi-finished product W' is stretched again, and the final composite elastic composite sheet W has more obvious wrinkle patterns, is more beautiful and has better elasticity in the free state.

[0106] Elastic material supply process A23:

[0107] Combination Figure 4 and Figure 10 In the elastic material supply process A23, multiple elastic materials T are continuously conveyed along the flow direction. Perpendicular to the flow direction, the first inner layer sheet W31 corresponds to the first intermediate sheet W21, and the second inner layer sheet W32 corresponds to the second intermediate sheet W22. Furthermore, the first inner layer sheet W31 and the first intermediate sheet W21 are located on one side of the flow centerline L, while the second inner layer sheet W32 and the second intermediate sheet W22 are located on the other side of the flow centerline.

[0108] The elastic material supply process A23 includes a guide wheel D set in the process for guiding the elastic material T, and a plurality of tension sensors J, wherein each tension sensor J corresponds to one elastic material T.

[0109] Specifically, the elastic material supply process A23 includes an elastic material supply unit G5, located between the third supply unit G3 and the fourth supply unit G4. The elastic material supply unit G5 includes multiple tension sensors J and guide rollers D arranged along the flow path to guide the elastic material T. Each tension sensor J corresponds to one elastic material T. After the multiple elastic materials T are unwound, the elastic material supply unit G5 continuously conveys the multiple elastic materials T along the flow direction.

[0110] Because the elastic material T is elastic, its tension directly affects the final forming state of the elastic composite sheet W. Therefore, tension sensors J are required, with each tension sensor J corresponding to one elastic material T, to monitor the tension of each elastic material T and adjust its tension in real time, providing stable tension conditions for the downstream bonding with the sheet. The elastic material T is conveyed under the guidance of guide rollers D.

[0111] Application of adhesives step A3:

[0112] Combination Figure 4 and Figure 10 In the adhesive application process A3, an adhesive is applied to the surface of each elastic material T. Specifically, the adhesive application process includes an adhesive application unit H for applying adhesive N to the surface of each elastic material T.

[0113] In embodiments of the present invention, the elastic material T consists of multiple spandex filaments (elastic bands), the number and position of which are determined according to the product. To securely fix the elastic material T between the first inner layer sheet W31 and the first intermediate sheet W21 of the elastic composite semi-finished product W', and to securely fix it between the second inner layer sheet W32 and the second intermediate sheet W22 of the elastic composite semi-finished product W', an adhesive N is applied to the elastic material T using an adhesive application unit H before it enters the elastic material composite process A4, through an adhesive application process A3. In this embodiment, the elastic material T consists of multiple spandex filaments, and the adhesive application unit H applies adhesive to each spandex filament, wherein the adhesive N is wrapped around the outer periphery of the spandex filament.

[0114] The elastic composite semi-finished product W' or the first inner layer sheet W31 and the second inner layer sheet W32 are disposed below the adhesive application unit H of the present invention, that is, one of the fourth supply unit G4 or the third supply unit G3 is located below the adhesive application unit H.

[0115] Since the elastic material supply unit G5 is located between the third supply unit G3 and the fourth supply unit G4, that is, the elastic material T is located between the first inner layer sheet W31 and the second inner layer sheet W32 of the third supply unit G3, and the elastic composite semi-finished product W' of the fourth supply unit G4, as shown below. Figure 4 and Figure 10As shown. Because the glue application unit H causes hot melt adhesive to fly off during the glue application process (due to the hot air blowing on the glue gun during glue application), to avoid the equipment being contaminated by the adhesive, an elastic composite semi-finished product W' or a first inner layer sheet W31 and a second inner layer sheet W32 is placed below the glue application unit H. In this embodiment, the elastic composite semi-finished product W' is placed below the glue application unit H, that is, the fourth supply unit G4 is located below the glue application unit H. This arrangement allows the hot melt adhesive to fly off to be carried away by the sheet, thereby both fixing the sheet and keeping the manufacturing equipment clean and tidy.

[0116] Elastic material composite process A4:

[0117] Combination Figure 4 and Figure 10 In the elastic material composite process A4, on one side of the process centerline L, the elastic material T extending along the process direction is composited between the first inner layer sheet W31 and the first intermediate sheet W21 of the elastic composite semi-finished product W', and on the other side of the process centerline L, the elastic material T extending along the process direction is composited between the second inner layer sheet W32 and the second intermediate sheet W22 of the elastic composite semi-finished product W', thereby forming the elastic composite sheet W.

[0118] Specifically, the elastic material composite process A4 includes a clamping composite roller 3, which comprises a drive roller and a clamping roller arranged opposite to each other. The drive roller and the clamping roller clamp and drive the first inner layer sheet W31, the first intermediate sheet W21 of the elastic composite semi-finished product W' on one side of the process centerline L, and the elastic material T disposed between the first inner layer sheet W31 and the first intermediate sheet W21 of the elastic composite semi-finished product W'.

[0119] Simultaneously, the drive roller and the clamping roller clamp and drive the second inner layer sheet W32, the second intermediate sheet W22 of the elastic composite semi-finished product W' on the other side of the process centerline L, and the elastic material T disposed between the second inner layer sheet W32 and the second intermediate sheet W22 of the elastic composite semi-finished product W'.

[0120] The clamping roller 3 of this invention increases the adhesion between the first inner layer sheet W31, the elastic material T, and the first intermediate sheet W21 of the elastic composite semi-finished product W', and also increases the adhesion between the second inner layer sheet W32, the elastic material T, and the second intermediate sheet W22 of the elastic composite semi-finished product W'. The drive roller is connected to a drive motor, and the speed of the composite material at this station can be adjusted by controlling and adjusting the drive motor.

[0121] Elastic material cutting process A5:

[0122] According to an embodiment of the present invention, the present invention further includes an elastic material cutting process A5 disposed downstream of the elastic material composite process A4.

[0123] Combination Figure 4 and Figure 11 The elastic material cutting process A5 includes an elastic material cutting unit 4. The elastic composite sheet W, formed by the clamping composite roller 3, enters the elastic material cutting unit 4 to cut the elastic material T. In the region corresponding to the composite inner sheet S2 in the outer covering layer S1 of the disposable diaper S, the elastic material T between the first inner layer sheet W31 and the first intermediate sheet W21 is cut to form a first elastic weakening region K1, and the elastic material T between the second inner layer sheet W32 and the second intermediate sheet W22 is cut to form a second elastic weakening region K2. The inner sheet S2 in the disposable diaper S is located inside the outer covering layer S1.

[0124] like Figure 11 As shown, in the region corresponding to the composite inner sheet S2 in the outer covering layer S1 of the disposable diaper S, the elastic material T between the first inner layer sheet W31 and the first intermediate sheet W21 of the elastic composite semi-finished product W' is cut to form a first elastic weakening area K1, causing it to completely or partially lose its elasticity. Similarly, the elastic material T between the second inner layer sheet W32 and the second intermediate sheet W22 of the elastic composite semi-finished product W' is cut to form a second elastic weakening area K2, causing it to completely or partially lose its elasticity. This is to prevent shrinkage caused by the first elastic weakening area K1 and the second elastic weakening area K2 after the inner sheet S2 is composited, thereby affecting the flatness of the composite and reducing product quality.

[0125] Export process A6:

[0126] According to an embodiment of the present invention, the present invention further includes an output process A6 disposed downstream of the elastic material cutting process A5, the output process including an output roller 5.

[0127] The elastic composite sheet W, after being cut by the elastic material cutting unit 4, is transported downstream by the output roller 5 to continue processing, in order to form an outer covering layer S1. Finally, the inner sheet S2 is laminated onto the outer covering layer S1 and then processed through downstream processes to finally form a disposable diaper S.

[0128] The outer sheet W1 is made of hot-air nonwoven fabric or spunbond nonwoven fabric, preferably hot-air nonwoven fabric. The outer sheet W1, the first intermediate sheet W21 and the second intermediate sheet W22 are materials with certain elastic shrinkage properties, so that the composite material formed after the outer sheet W1, the first intermediate sheet W21 and the second intermediate sheet W22 are relatively flat. The composite material is further compounded with the subsequent elastic material T and the first inner sheet W31 and the second inner sheet W32 under the tensile state, which also ensures the composite effect.

[0129] The following points need to be explained:

[0130] (1) The accompanying drawings of the embodiments of the present invention only involve the structures involved in the embodiments of the present invention. Other structures can refer to the general design.

[0131] (2) For clarity, the thickness of layers or regions is enlarged or reduced in the drawings used to describe embodiments of the present invention; that is, these drawings are not drawn to actual scale. It is understood that when an element such as a layer, film, region, or substrate is referred to as being “above” or “below” another element, the element may be “directly” located “above” or “below” the other element, or there may be intermediate elements.

[0132] (3) Where there is no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0133] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for manufacturing an elastic composite sheet, used to manufacture an elastic composite sheet for the outer covering layer of disposable diapers, characterized in that, The manufacturing method includes the following steps: Pre-processing steps for elastic composite semi-finished products: used to process and form elastic composite semi-finished products, including a first supply step and a second supply step arranged in parallel in the process, and a sheet bonding step located downstream of the first supply step and the second supply step; First feeding process: After unwinding the outer sheet, it is continuously fed to the sheet bonding process; Second supply process: The first intermediate sheet and the second intermediate sheet, which are parallel to each other and perpendicular to the process direction, are continuously fed to the sheet joining process along the process direction, wherein the first intermediate sheet is located on one side of the process center line and the second intermediate sheet is located on the other side of the process center line. Sheet bonding process: The sheet bonding process includes an ultrasonic device; the sheet bonding process bonds and fixes the outer sheet extending along the flow direction to the first intermediate sheet and the second intermediate sheet located on both sides of the flow centerline, so as to form a first joint between the outer sheet and the first intermediate sheet, and a second joint between the outer sheet and the second intermediate sheet, thereby forming the elastic composite semi-finished product; wherein, when viewed from the outer sheet towards the first intermediate sheet and the second intermediate sheet, the outer sheet can simultaneously and completely cover the first intermediate sheet and the second intermediate sheet. Among them, the process centerline is the baseline for the process design of disposable diapers in the manufacturing equipment for disposable diapers; Elastic material composite supply process: includes a third supply process, a fourth supply process and an elastic material supply process arranged in parallel along the process flow; wherein, the elastic material supply process is located between the third supply process and the fourth supply process; The third supply process: The first inner layer sheet and the second inner layer sheet, which are parallel to each other and perpendicular to the flow direction, are continuously conveyed to the downstream side along the flow direction. The first inner layer sheet is located on one side of the flow center line, and the second inner layer sheet is located on the other side of the flow center line. Fourth supply process: The elastic composite semi-finished product is continuously conveyed to the downstream side along the flow direction; Elastic material supply process: Continuously conveying multiple elastic materials along the flow direction; Along the direction perpendicular to the process flow, the first inner layer sheet corresponds to the first intermediate sheet; the second inner layer sheet corresponds to the second intermediate sheet; and the first inner layer sheet and the first intermediate sheet are located on one side of the process centerline, while the second inner layer sheet and the second intermediate sheet are located on the other side of the process centerline. Adhesive application process: Apply adhesive to the surface of each elastic material; Elastic material composite process: On one side of the process centerline, elastic material extending along the process direction is composited between the first inner layer sheet and the first intermediate sheet of the elastic composite semi-finished product, and on the other side of the process centerline, elastic material extending along the process direction is composited between the second inner layer sheet and the second intermediate sheet of the elastic composite semi-finished product, thereby forming the elastic composite sheet. In the first supply process, the supply speed is faster than that in the second supply process, so as to stretch the outer sheet and form wrinkles in the outer sheet. In the fourth supply process, the supply speed is faster than that in the third supply process, so as to stretch the outer sheet again.

2. The manufacturing method according to claim 1, characterized in that, The supply speed in the first supply process and the supply speed in the second supply process are adjusted separately, and the supply speed in the first supply process is 1%-15% faster than the supply speed in the second supply process.

3. The manufacturing method according to claim 1, characterized in that, The first intermediate sheet and the second intermediate sheet have the same elongation and are both greater than the elongation of the outer sheet.

4. The manufacturing method according to claim 3, characterized in that, The elongation of the first intermediate sheet and the second intermediate sheet is 5%-15% greater than that of the outer sheet.

5. The manufacturing method according to claim 1, characterized in that, The ultrasonic device includes a first ultrasonic welding head, a second ultrasonic welding head, and an ultrasonic bottom roller. The first ultrasonic welding head and the second ultrasonic welding head are arranged parallel to each other in the axial direction and are simultaneously arranged opposite to the ultrasonic bottom roller.

6. The manufacturing method according to claim 5, characterized in that, The ultrasonic bottom roller has multiple axially extending and arranged joint patterned parts spaced apart on its circumferential surface. The joining patterned portion includes a connected base and a protrusion, the base and the protrusion are spaced apart, and the protrusion is higher than the base. The surface of the protrusion is provided with a patterned design. The protrusion is welded to the first ultrasonic welding head and the second ultrasonic welding head to form the first joining portion and the second joining portion of the elastic composite semi-finished product.

7. The manufacturing method according to claim 1, characterized in that, The elastic material composite process includes a clamping composite roller, wherein the clamping composite roller includes a drive roller and a clamping roller arranged opposite to each other; The drive roller and the clamping roller clamp and drive the first inner layer sheet, the first intermediate sheet of the elastic composite semi-finished product, and the elastic material disposed between the first inner layer sheet and the first intermediate sheet of the elastic composite semi-finished product on one side of the process center line. Simultaneously, the drive roller and the clamping roller clamp and drive the second inner layer sheet, the second intermediate sheet of the elastic composite semi-finished product, and the elastic material disposed between the second inner layer sheet and the first intermediate sheet of the elastic composite semi-finished product on the other side of the process centerline.

8. The manufacturing method according to claim 1, characterized in that, The first supply process includes a first free roller disposed on the flow path for guiding the outer sheet; The second supply process includes a second free roller disposed in the flow path to guide the first inner sheet and the second inner sheet; The third supply process includes a third free roller disposed in the flow path to guide the first inner sheet and the second inner sheet; The fourth supply process includes a fourth free roller disposed on the flow path to guide the elastic composite semi-finished product.

9. The manufacturing method according to claim 1, characterized in that, The elastic material supply process includes guide rollers installed on the flow path to guide the elastic material.

10. The manufacturing method according to claim 9, characterized in that, The elastic material supply process further includes multiple tension sensors, wherein each tension sensor corresponds to one elastic material.

11. The manufacturing method according to claim 1, characterized in that, The adhesive application process includes an adhesive application unit, and the elastic composite semi-finished product or the first inner layer sheet and the second inner layer sheet are disposed below the adhesive application unit.

12. The manufacturing method according to claim 1, characterized in that, The manufacturing method further includes an elastic material cutting process disposed downstream of the elastic material composite process, the elastic material cutting process including an elastic material cutting unit; The elastic material cutting unit is used to cut the elastic material between the first inner layer sheet and the first intermediate sheet in the position area corresponding to the composite inner sheet of the outer covering layer of the disposable diaper to form a first elastic weakening area. And the elastic material between the second inner sheet and the second intermediate sheet is cut to form a second elastic weakening zone; The inner pad of the disposable diaper is located inside the outer covering layer.

13. The manufacturing method according to claim 12, characterized in that, The manufacturing method further includes an output process located downstream of the elastic material cutting process, the output process including an output roller.

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