Preparation method of absorbent material

Abstract

The preparation method of the absorptive material comprises the steps that S1, a base body is provided, the base body is laid on a bottom plate, and the bottom plate comprises a bottom hole; s2, a punching head arranged on the upper side of the bottom plate punches the base body, one part of the base body is separated from the base body to form an attached body, and the attached body is bent into the bottom hole; and S3, the punching head is reset, the base body and the bottom plate move relatively, and the attaching body bent into the bottom hole is bent and attached to the base body to form the absorptive material. And on the other hand, the absorptive material prepared by the method can generate a better absorption effect on high-viscosity body fluid and reduce back infiltration.

Description

Technical Field

[0001] The invention relates to a method for preparing an absorbent material. Background Art

[0002] With the improvement of people's living standards, disposable absorbent products, such as sanitary napkins, diapers, breast pads, nursing pads and other products are widely used. These disposable absorbent products usually include a liquid-permeable surface layer, a liquid-impermeable bottom layer and an absorbent layer sandwiched between the surface layer and the bottom layer.

[0003] The absorption layer is usually made of fluff pulp, and in order to further improve the absorption performance, structures such as guide grooves are widely set on the absorption layer. In practice, people have found that the absorption performance of the absorption layer formed by these methods still cannot meet the requirements for highly viscous body fluids. In further improvements, through holes are usually set on the absorption layer, such as those shown in JP2011104058A, CN103349590A, CN102743258A and other documents.

[0004] However, when through holes are directly set on the absorption layer, when the body fluid is not viscous, or when there are both viscous and non-viscous body fluids, such as milk, which is a body fluid between urine and menstrual blood, and both viscous and non-viscous body fluids, when the absorption layer is squeezed, water or body fluids will directly seep back from the through holes, causing inconvenience in use. Therefore, it is necessary to prepare a new structural form to solve the above technical problems. Summary of the invention

[0005] To this end, the present invention provides a method for preparing an absorbent material to solve the above technical problems.

[0006] A method for preparing an absorbent material, comprising: S1: providing a substrate and laying the substrate on a bottom plate, wherein the bottom plate includes a bottom hole; S2: a punching head disposed on the upper side of the bottom plate punches the base body and separates a portion of the base body from the base body to form an attached body, and the attached body is bent into the bottom hole; S3: The punching head is reset, the base and the bottom plate move relative to each other, and the attached body bent into the bottom hole is bent and attached to the base to form an absorbent material.

[0007] Among them, the bottom hole includes a second edge line and a side edge line forming a second cutting edge, the punching head includes a first cutting edge, and in step S2, the first cutting edge and the second cutting edge cooperate to shear the substrate to form an incision at a corresponding position of the substrate. The punching head also includes a notch portion, and after the incision is formed, a connecting portion is formed at a position corresponding to the second edge line.

[0008] Wherein, in step S2, the attached body includes a connecting portion and an attaching portion, the attached body is bent from the connecting portion, and the density of the connecting portion is greater than the density of the base body.

[0009] Wherein, after the attached body is bent into the bottom hole, the attached portion is attached to the inner wall of the bottom hole and is perpendicular to the base body.

[0010] Wherein, in step S3, the attachment portion is bent 90 degrees again and attached to the substrate.

[0011] Among them, in step S3, the substrate moves on the bottom plate in the downstream direction, and the attached portion passes through the side edge line, and the attached portion is squeezed and bent by the side edge line and the bottom plate to form a shape attached to the substrate.

[0012] Among them, the punching head includes a C-shaped cutting head, the C-shaped cutting head includes a hollow part, the end of the C-shaped cutting head forms a first cutting edge, the first cutting edge alone applies a shear force to the substrate and forms an incision at a position corresponding to the first cutting edge, thereby forming an attached body.

[0013] Wherein, a negative pressure cavity connected to the bottom hole is also provided at the lower side of the bottom hole, and the negative pressure cavity and the bottom hole are in a negative pressure state. In step S2, the attached body bends into the bottom hole under the action of the negative pressure.

[0014] Wherein, the bottom plate comprises an attachment surface, the attachment surface is a plane or a curved surface, and the substrate is laid on the attachment surface of the bottom plate.

[0015] Wherein, after step S3, the method further includes the steps of providing a main absorbent body and laying an absorbent material on the main absorbent body.

[0016] Beneficial effects: The present invention provides a method for preparing an absorbent material, comprising: S1: providing a substrate and laying the substrate on a bottom plate, wherein the bottom plate includes a bottom hole; S2: a punching head arranged on the upper side of the bottom plate punches the substrate and separates a part of the substrate from the substrate to form an attached body, and the attached body bends into the bottom hole; S3: the punching head is reset, the substrate and the bottom plate move relative to each other, and the attached body bent into the bottom hole is bent and attached to the substrate to form an absorbent material. On the one hand, no excess material will be generated when preparing through holes by using this method, and on the other hand, the absorbent material prepared by this method can have a better absorption effect on high-viscosity body fluids and reduce re-seepage. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of an absorbent material according to an embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of the middle AA section; Figure 3 A schematic diagram of the shape when a main absorbent body is arranged under the absorbent material; Figure 4-Figure 9 A schematic diagram of a process for forming an absorbent material; Fig.10 Another schematic diagram of an apparatus for forming an absorbent material; Fig.11 for Fig.10 Schematic diagram of the middle BB section; Fig.12 for Fig.10 Schematic diagram of the front view of the midsole plate.

[0018] Component Description: Base 10; first surface 101; second surface 102; through hole 11, 421; first edge line 111; attachment body 12; connecting part 121; protrusion 120; attachment part 122; cavity 123; main absorbent body 13; extrusion area 131; punching head 21, 31; first cutting edge 211, 311; notch part 212; bottom plate 22, 41; bottom hole 221; second cutting edge 222; second edge line 223, 412; negative pressure cavity 23; C-shaped cutting head 311; hollow part 312, side edge line 411. DETAILED DESCRIPTION

[0019] Please refer to Figure 4-Figure 9 ,exist Figure 4-Figure 9 The device for forming the absorbent material and the steps of using the device to prepare the absorbent material are shown in the figure. Specifically, the method for preparing the absorbent material includes the following steps.

[0020] S1: providing a substrate 10 and laying the substrate 10 on a bottom plate 22 , wherein the bottom plate 22 includes a bottom hole 221 .

[0021] The matrix 10 is mainly composed of fibers interwoven to form a network structure. The main meaning is that the content of fibers in the matrix 10 is greater than or equal to 80%. It can be understood that the matrix 10 can also contain absorbent materials such as SAP.

[0022] The fibers can be interwoven by winding or bonding. After interweaving, the fibers are properly connected to form a three-dimensional network structure. The winding can be formed by air winding, needle-punching winding, hydroentanglement, etc. The bonding can include but is not limited to chemical bonding and thermal bonding, such as hot rolling or bonding by hot air flow.

[0023] It is understandable that the fibers may be natural fibers, synthetic fibers or a mixture of synthetic fibers and natural fibers. The natural fibers may be wood pulp fibers, bamboo pulp fibers, etc. In a specific embodiment, the natural fibers are coniferous wood fluff pulp fibers.

[0024] When the fiber is a synthetic fiber, the fiber may be specifically a thermoplastic polymer, and the thermoplastic polymer may be a polyolefin, polyester, ethylene copolymer, propylene copolymer, butene copolymer, and a combination thereof, and the polyolefin may specifically include polyethylene, polypropylene, a copolymer of ethylene with butene, hexene or octene, and a copolymer of polypropylene and ethylene. The polyolefin may include a homopolymer or a copolymer (such as a propylene-α-olefin copolymer). In a specific embodiment, the fiber is formed by a polyethylene homopolymer or a polypropylene homopolymer, a copolymer thereof, a mixture of polyethylene and polypropylene, a polyester, a polyester copolymer, and / or a polyester mixture.

[0025] In addition, the fiber may further include additives, including heat stabilizers, light stabilizers, slip agents, waxes, and additives that make the fabric hydrophilic or hydrophobic. In addition, the fiber can be made according to spinning techniques well known in the art. The easiest is to use a spunbond process, by which nonwoven fabrics can be directly formed, specifically, spunbond fibers are usually produced by extruding a molten polymer through a larger spinneret (every linear meter has thousands of holes), or by extruding a molten polymer from a cylinder of a smaller spinneret (such as comprising as few as 40 holes). After leaving the spinneret, the molten fiber is quenched by a cross-flow air quenching system, then pulled away from the spinneret and attenuated by high-speed air. Laying filaments to form a nonwoven layer occurs on a permeable conveyor belt. Spunbond fibers are usually continuous, and their fiber diameter is between about 10-100 μm.

[0026] In addition, in order to improve the ability of substrate 10 to absorb and diffuse body fluids, substrate 10 may be locally treated to make substrate 10 hydrophilic or hydrophobic, such as treating the surface of substrate 10 with a hydrophilic surfactant or treating substrate 10 with a fluorocarbon or silicon material.

[0027] It can be understood that the substrate 10 is in sheet form. In some embodiments, the substrate 10 can also be a continuous sheet and is configured to be continuously supplied in the downstream direction, such as the substrate 10 is wound on a core tube and laid in the downstream direction under the action of a laying device.

[0028] The bottom plate 22 includes an attachment surface, and the substrate 10 is laid on the attachment surface of the bottom plate 22. It can be understood that the attachment surface can be a plane or a curved surface. When the bottom plate is a part of a roller body, the attachment surface is a curved surface.

[0029] Please refer to Figure 6 ,exist Figure 6 The projection of the punching head 21 on the bottom hole 221 is shown in the figure. The bottom hole 221 includes a second edge line 223 and an outer edge line forming a second cutting edge 222. The second edge line 223 is straight and is used to enable the formed attachment portion 122 to bend along the second edge line 223.

[0030] In this embodiment, the outer side line is in an arc shape to cooperate with the punching head 21 to form a substantially circular through hole 11 .

[0031] S2: The punching head 21 disposed on the upper side of the bottom plate 22 punches the base 10 and separates a portion of the base 10 from the base 10 to form an attached body 12 , and the attached body 12 is bent into the bottom hole 221 .

[0032] It can be understood that the attached portion 122 of the attached body 12 formed by separation is bent into the bottom hole 221 . More specifically, the attached portion 122 of the attached body 12 is separated from the base 10 .

[0033] Furthermore, when the attached body 12 is bent into the bottom hole 221 , it is attached to the inner wall of the bottom hole 221 and is perpendicular to the base body 10 .

[0034] The punching head 21 includes a first cutting edge 211, and the first cutting edge 211 cooperates with the second cutting edge 222 to shear the substrate 10 to form an incision at a corresponding position of the substrate 10. At the same time, the punching head 21 includes a notch portion 212, which corresponds to the second edge line 223 to avoid shearing at the second edge line 223, thereby forming a connecting portion 121 at a position corresponding to the second edge line 223.

[0035] In this embodiment, the punching head 21 is arranged on the upper side of the bottom plate 22, and the base 10 is arranged between the punching head 21 and the bottom plate 22. The punching head 21 is arranged corresponding to the bottom hole 221, and moves from top to bottom through the shearing action of the first cutting edge 211 and the second cutting edge 222 to separate and form the attachment portion 122. At the same time, under the action of the punching head 21, the attachment portion 122 continues to move downward and bends into the bottom hole 221.

[0036] In addition, due to the presence of the notch portion 212 , the attachment portion 122 has a receiving area after being bent, thereby preventing the attachment portion 122 from forming wrinkles when being bent.

[0037] Furthermore, a negative pressure chamber 23 connected to the bottom hole 221 is provided on the lower side of the bottom hole 221. The negative pressure chamber 23 is connected to a negative pressure device and makes the negative pressure chamber 23 present a negative pressure state. It can be understood that the bottom hole 221 is also in a negative pressure state through the negative pressure chamber 23. Under the action of the negative pressure, the attachment portion 122 will bend more easily and remain in a bent state, or, during the upward movement of the punching head 21, the attachment portion 122 can still remain in a bent state.

[0038] Please refer to Figure 10-12 In another embodiment, the punching head 31 includes a C-shaped cutting head 311, and the C-shaped cutting head 311 includes a hollow portion 312. At the same time, the end of the C-shaped cutting head 311 forms a first cutting edge 311, and the first cutting edge 311 can apply a shear force to the substrate alone and form an incision at a position corresponding to the first cutting edge 311, thereby forming an attachment portion. In this case, the side edge line 411 of the bottom hole 421 may not correspond to the first cutting edge 311, that is, the side edge line 411 may be slightly smaller than the size of the first cutting edge 311. Similarly, after cutting, the attachment portion bends downward along the second edge line 412 under the action of negative pressure and enters the bottom hole 421.

[0039] It can be understood that in this manner, the punching head 31 may not enter the bottom hole 421, thereby reducing the movement length and improving the slitting efficiency.

[0040] It can be understood that the through hole 11 is not limited to a circular hole, but can also be a hole of other shapes.

[0041] S3: The punching head 21 is reset, the base 10 and the bottom plate 22 move relative to each other, and the attached body 12 bent into the bottom hole 221 is bent and attached to the base 10 to form an absorbent material.

[0042] After step S2, the punching head 21 moves from bottom to top and resets to perform the next punching. The substrate 10 moves downstream on the bottom plate 22, and the attachment portion 122 is further bent and formed into a shape attached to the substrate 10 when passing through the side edge line under the action of the side edge line and the upper surface of the bottom plate 22.

[0043] Please refer to Figure 1 and Figure 2 ,exist Figure 1 and Figure 2The front view and cross-sectional view of the formed absorbent material are shown in the figure, wherein the attached body 12 includes a connecting portion 121 and an attaching portion 122, wherein the connecting portion 121 is connected to the substrate 10, and the attaching portion 122 is a portion separated from the substrate 10, and after being separated from the substrate 10, a through hole 11 is formed at a corresponding position of the substrate 10, and at the same time, the attaching portion 122 is folded 180° along a fold line and attached to the substrate 10.

[0044] More specifically, the base 10 includes a first surface 101 and a second surface 102. The attached body 12 is flipped 180° along the inner side of the connecting portion 121 and the second surface 102 is attached to the second surface 102 of the base 10. It can be understood that after folding, one side edge of the connecting portion 121 forms a side edge of the through hole 11. For the convenience of description, this side edge is referred to as the first edge line 111.

[0045] It can be understood that the first side line 111 is in a straight line shape.

[0046] It can be understood that since the attachment body 12 is folded along a fold line and the attachment portion 122 is attached to the base 10, the density of the connecting portion 121 area connected to the first edge line 111 will increase during the folding process, and the pores in this area will be reduced. According to the principle of capillary action, the capillary diameter of the connecting portion 121 adjacent to the first edge line 111 will be reduced, thereby increasing the capillary action.

[0047] Please also refer to Figure 3 When the main absorbent body 13 is disposed on the lower side of the absorbent material, when the second surface 102 is attached to the main absorbent body 13, a protrusion 120 is formed at the corresponding position of the attached body 12, and a cavity 123 is formed at the end position of the attached portion 122, and the through hole 11 is located on one side of the protrusion 120. In this case, the following effects are brought about: First, for viscous body fluids, the viscous body fluids can pass through the through holes 11 and thus be quickly absorbed by the main absorbent body 13 .

[0048] Second, at the same time, since the connection part 121 at the edge of the through hole 11 has a high density and a strong capillary effect, various body fluids can quickly penetrate along the connection part 121 and be absorbed by the main absorbent body 13.

[0049] 3. When the body fluid absorbed by the main absorbent body 13 is subjected to pressure, the protrusions 120 will have more contact with the skin. In fact, the body fluid needs to pass through the protrusions 120 during the squeezing process of the main absorbent body 13 in order to be felt by the user. However, due to the interface between the attachment portion 122 and the substrate 10, the body fluid will diffuse laterally when reaching the interface. At the connecting portion 121, due to its higher density, the body fluid is not easily "squeezed out" from the protrusions 120, thereby reducing re-seepage.

[0050] Fourth, due to the existence of the protrusion 120, a squeezing area 131 is formed in the area corresponding to the main absorbent body 13 and the protrusion 120. In practice, the detailing effect of this position will be stronger, so that more body fluids are absorbed in this area, and more body fluids are squeezed out from this position during squeezing. Combined with the description of "three" above, body fluids are not easy to seep back.

[0051] Fifth, due to the existence of the cavity 123 and the through hole 11, the touch of the entire absorbent material is enhanced. In addition, the cavity 123 can increase the liquid capacity and increase the absorption of body fluids.

[0052] In further research, by adopting the above measures, under the condition of using the same substrate 10 and through-holes 11, the average back-seepage was reduced by 5.7%.

[0053] Furthermore, the aperture of the through hole 11 should be less than or equal to 5 mm, so that the viscous body fluid can be absorbed by the main absorbent body 13 through the through hole 11, but the body fluid will not be squeezed out of the through hole 11 when the main absorbent body 13 is squeezed. More preferably, the aperture of the through hole 11 is 1 to 2 mm.

[0054] Furthermore, the base body 10 has a thickness of 0.1-3 mm to form the protrusion 120 and enable the main absorbent body 13 to form a pressing area 131. More preferably, the thickness of the base body 10 is 0.3-2 mm.

[0055] Furthermore, the main absorbent body 13 should have a higher thickness to form a larger absorption capacity. In a specific embodiment, the main absorbent body 13 is a three-dimensional network structure formed by interweaving fluff pulp, and the main absorbent body 13 may also include SAP.

[0056] It can be seen that in this preparation method, the attached body 12 formed by punching and bending will not separate from the base body 10, that is, no residual material will be generated, which can further reduce the equipment and steps for collecting and processing the residual material.

[0057] It can be understood that the downstream direction is the direction from the second edge line 223 to the side edge line, so that the attachment portion 122 can pass through the side edge line.

[0058] It can be understood that when the absorbent material further includes a main absorbent body 13 , after step S3 , the step of providing the main absorbent body 13 and laying the absorbent material formed in step S3 on the main absorbent body 13 is also included.

[0059] In addition, it can be understood that in the present invention, the attachment 12 and the base 10 are not fixedly combined, so that the body fluid can diffuse along the interface between the attachment 12 and the base 10.

[0060] The above description is only an implementation mode of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing an absorbent material, characterized in that: include: S1: providing a substrate and laying the substrate on a bottom plate, wherein the bottom plate includes a bottom hole; S2: a punching head disposed on the upper side of the bottom plate punches the base body and separates a portion of the base body from the base body to form an attached body, and the attached body is bent into the bottom hole; S3: The punching head is reset, the base and the bottom plate move relative to each other, and the attached body bent into the bottom hole is bent and attached to the base to form an absorbent material.

2. The preparation method according to claim 1, characterized in that The bottom hole includes a second edge line and a side edge line forming a second cutting edge, and the punching head includes a first cutting edge. In step S2, the first cutting edge and the second cutting edge cooperate to shear the substrate to form an incision at a corresponding position of the substrate. The punching head also includes a notch portion, and after the incision is formed, a connecting portion is formed at a position corresponding to the second edge line.

3. The preparation method according to claim 2, characterized in that: In step S2, the attached body includes a connecting portion and an attaching portion, the attached body is bent from the connecting portion, and the density of the connecting portion is greater than the density of the base body.

4. The preparation method according to claim 3, characterized in that: After the attached body is bent into the bottom hole, the attached portion is attached to the inner wall of the bottom hole and is perpendicular to the base body.

5. The preparation method according to claim 4, characterized in that: In step S3, the attachment portion is bent again by 90° and attached to the substrate.

6. The preparation method according to claim 2, characterized in that: In step S3, the substrate moves on the bottom plate toward the downstream direction, and the attached portion passes through the side edge line, and the attached portion is squeezed and bent by the side edge line and the bottom plate to form a shape attached to the substrate.

7. The preparation method according to claim 1, characterized in that: The punching head includes a C-shaped cutting head, the C-shaped cutting head includes a hollow portion, the end of the C-shaped cutting head forms a first cutting edge, the first cutting edge alone applies a shear force to the substrate and forms an incision at a position corresponding to the first cutting edge, thereby forming an attached body.

8. The preparation method according to claim 1, characterized in that: A negative pressure cavity connected to the bottom hole is also provided at the lower side of the bottom hole. The negative pressure cavity and the bottom hole are in a negative pressure state. In step S2, the attached body bends into the bottom hole under the negative pressure.

9. The preparation method according to claim 1, characterized in that: The bottom plate comprises an attachment surface, which is a plane or a curved surface, and the substrate is laid on the attachment surface of the bottom plate.

10. The preparation method according to claim 1, characterized in that: After step S3, the method further includes providing a main absorbent body and laying an absorbent material on the main absorbent body.

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