A process and equipment for manufacturing diaper absorbent core with hot air skin-friendly layer

Abstract

The present invention discloses a process and equipment for manufacturing a diaper absorbent core with a hot air skin-friendly layer. The process for manufacturing the diaper absorbent core includes: firstly, pre-treating low-melting point fibers and plant fibers and adding them to a mixing device together with a polymer material, and then air-forming a web to form a composite after mixing; then, laying a hot air non-woven fabric on the surface of the composite to form a core composite; then, entering an oven to bond and dry the hot air non-woven fabric to form an absorbent core; and finally, rolling up for standby use after cooling and finalization. The present invention forms a diaper absorbent core by composite polymer materials with a structure of interlaced mixed fibers, and wrapping the mixed materials with a surface layer and a bottom layer, which can greatly improve the absorption capacity and efficiency of the absorbent core, making the overall structure soft, comfortable and stable, laying a fiber layer on the bottom layer to improve the diffusion capacity, and using a hot air non-woven fabric on the surface layer to simplify the production process and reduce production costs.

Description

Technical Field

[0001] The invention relates to the technical field of diaper cores, in particular to a process and equipment for manufacturing a diaper absorbent core with a hot air skin-friendly layer. Background Art

[0002] Absorbent sanitary products such as diapers are generally composed of a liquid-permeable surface layer that is mainly used in contact with the skin, a liquid-impermeable bottom layer that is not used in contact with the skin, and an absorbent core layer between the liquid-permeable surface layer and the liquid-impermeable bottom layer. The absorbent core layer mainly has the function of absorbing, storing, and locking body fluids, and is a key structural layer to measure the absorption performance of absorbent sanitary products.

[0003] The absorbent core layer is generally designed with hydrophilic fibers and polymer absorbent resin particles in a certain proportion and structural distribution. With the development of ultra-thin absorbent sanitary products such as diapers, the common absorbent core bulk fiber molding method is currently mainly composed of the upper layer: hydrophilic fibers, the middle layer: a uniform mixture of hydrophilic fibers / polymer absorbent resin particles, and the bottom layer: hydrophilic fibers. The three-layer structure is formed by spraying hot melt adhesive, commonly known as a "sandwich" mixed absorbent core. However, because hydrophilic fibers do not have a capillary structure, they cannot conduct fecal fluid multiple times after absorbing water, making the overall absorption efficiency slow. After the hydrophilic fibers absorb fecal fluid for the first time, the fecal fluid will be filled inside, which is not conducive to the subsequent absorption of fecal fluid, and it is easy to cause the core to absorb fecal fluid in time and leak. In addition, hydrophilic fibers are non-degradable materials, and their large proportion in the absorbent core has a certain impact on the environment.

[0004] At present, there is a need for a fiber structure that can accelerate absorption and occupy less space to lock polymer absorbent resin particles. Plant fibers have always been the focus of attention because plant fibers have a capillary structure and can absorb feces multiple times, which is convenient for transferring feces with polymer materials and accelerating absorption. However, the fiber length of plant fibers is too short to provide a stable structure, and the hydrophilic fiber length is too long and needs to be combed and formed, resulting in complex processing and structure and affecting the water absorption and expansion of polymers. Therefore, how to make 8-30mm low-melting point fibers, plant fibers and polymer materials be mixed together by airflow and provide a stable composite structure and good absorption efficiency has become a problem that needs to be solved. Summary of the invention

[0005] In view of the technical defects existing in the background technology, the present invention proposes a diaper absorbent core manufacturing process and equipment with a hot air skin-friendly layer, which solves the above technical problems and meets the actual needs. The specific technical solution is as follows:

[0006] A process for manufacturing a diaper absorbent core with a hot air skin-friendly layer, comprising:

[0007] Step S1: low-melting-point fibers and plant fibers with a fiber length of 8-30 mm are pretreated to form mixed fibers with a relative content of low-melting-point fibers of 10-40%, and the mixed fibers are added to a mixing device together with a polymer material, and after mixing, they are air-laid to form a composite;

[0008] Step S2: After the composite comes out of the mixing device, a hot air non-woven fabric is laid on the surface thereof to form a core composite;

[0009] Step S3: the core composite enters an oven for hot air nonwoven bonding and drying to form an absorbent core with a relative moisture content of 6-10%;

[0010] Step S4: the absorbent core is cooled and shaped in a cooling box and then rolled up.

[0011] As a further technical solution of the present invention, the preprocessing in step S1 includes the following steps:

[0012] Step a1: the low-melting point fiber and the plant fiber are loosened by a coarse loosening device and stored in a fiber storage tank;

[0013] Step a2: The low melting point fiber and the plant fiber are taken from the fiber storage tank by a fine loosening device and then mixed in a crusher.

[0014] The mixed fibers have a relative content of 10-40% of low melting point fibers. After mixing, the mixed fibers are conveyed to a mixing device via a feeding fan.

[0015] As a further technical solution of the present invention, the mixed air-laid web in step S1 comprises the following steps:

[0016] Step b1: the mixed fibers enter the mixing device from the upper wind chamber at the upper end of the mixing device, are broken up by the first roller group of the mixing device, and then fall into the polymer mixing chamber of the mixing device;

[0017] Step b2: the polymer material enters the polymer mixing chamber through the polymer feeding group of the mixing device and is mixed with the mixed fibers, and then is mixed and broken up by the second roller group of the mixing device to form a core mixed material;

[0018] Step b3: the core mixed material is dispersed and mixed and then falls into the negative pressure air cavity of the mixing equipment, and is evenly dropped onto the forming mesh belt covered with the composite bottom layer by the downward negative pressure wind force to form a composite body.

[0019] As a further technical solution of the present invention, the manufacturing process of the composite bottom layer in step b3 comprises the following steps:

[0020] Step c1: the pre-treated mixed fibers with a fiber length of 8-30 mm enter the mixing device from the upper wind chamber at the upper end of the mixing device, are broken up by the first roller group of the mixing device, and then fall into the polymer mixing chamber of the mixing device;

[0021] Step c2: The second roller group mixes and breaks up the mixture, and then falls into the negative pressure air chamber of the mixing device, and the downward negative pressure wind force evenly falls on the forming mesh belt covered with the bottom layer to form a composite bottom layer.

[0022] As a further technical solution of the present invention, the oven temperature in step S3 is 110-140°C.

[0023] A mixing device for raw materials of an absorbent core, comprising a mixing device and a feeding device and a negative pressure device connected thereto, wherein the mixing device comprises an upper air chamber, a first roller group, a polymer mixing chamber, a second roller group, a negative pressure air chamber, a negative pressure lower air chamber, and a forming mesh belt arranged between the negative pressure air chamber and the negative pressure lower air chamber, wherein the upper end of the upper air chamber is provided with a ventilation top cover connecting the inside and outside of the mixing device, at least one fiber feed port is provided on the side wall of the upper air chamber and connected to the feeding device, and at least one set of first rollers is provided between the upper air chamber and the polymer mixing chamber. Roller group, the first roller group includes at least two breaking rollers, at least one polymer feed port connected to the outside is provided on the side wall of the polymer mixing chamber, the polymer feed port connects the polymer mixing chamber and the polymer feed group, at least one second roller group is provided between the negative pressure air chamber and the polymer mixing chamber, the second roller group includes at least four breaking rollers, the forming mesh belt is arranged around the negative pressure lower air chamber, the lower end of the negative pressure lower air chamber is provided with a mesh belt correction device connected to the forming mesh belt, and the negative pressure lower air chamber is provided with a negative pressure air port connected to the negative pressure device.

[0024] As a further technical solution of the present invention, the feeding device includes a crusher, a feeding pipe connecting the crusher and the fiber feeding port, and a feeding fan arranged at the lower end of the feeding pipe.

[0025] As a further technical solution of the present invention, the beating roller includes a cotton stirring roller, a vertical seat bearing provided at both ends of the cotton stirring roller for fixing, and a plurality of cotton stirring needles evenly arranged around the circumference of the cotton stirring roller, a pressure plate is provided at the connection between the cotton stirring needle and the cotton stirring roller, and sealing plates are also provided at both ends of the cotton stirring roller.

[0026] As a further technical solution of the present invention, the length of the stirring needles of the stirring rollers of the first roller group is greater than the length of the stirring needles of the stirring rollers of the second roller group.

[0027] As a further technical solution of the present invention, when the number of the first roller group and the second roller group is greater than two, the cotton stirring rollers in each roller group are vertically arranged.

[0028] The beneficial effects of the present invention are:

[0029] (1) The absorbent core manufacturing process pre-treats the low-melting point fiber and the plant fiber, loosens the mixed fiber materials while mixing them, and facilitates the subsequent interweaving and mixing with the polymer material. Before mixing with the polymer material, the gap between the fiber materials is increased by a scattering roller to facilitate the mixing of the polymer material therein. After mixing, the fiber materials are evenly mixed again by a scattering roller, and the mixed materials are evenly mixed on the forming mesh belt with the bottom layer. The fiber materials can be fully dispersed to provide a stable coating structure for the polymer, and the capacity of the polymer material can be increased, thereby ensuring the absorption capacity of the core. By adding plant fibers to the low-melting point fibers, the stability of the structure can be increased, and the capillary structure of the plant fibers can be used to absorb and transfer fecal fluid multiple times, thereby improving the absorption efficiency of the core.

[0030] (2) Before compounding with polymer materials, low-melting-point fibers and plant fibers can be laid on the bottom layer to form a diffusion layer, which can facilitate the core to diffuse the stool liquid to the surrounding area after absorbing liquid, thereby improving the absorption capacity and improving the connectivity with the bottom layer structure when compounding with polymer materials.

[0031] (3) The surface layer is made of hot air non-woven fabric. Due to the characteristics of the hot air non-woven fabric itself, the surface layer is compounded with the absorbent core during the drying stage, which improves production efficiency and simplifies the production process, and can effectively reduce the production cost of the absorbent core.

[0032] (4) The mixing equipment first breaks up the mixed fibers through the first roller group, thereby improving the mixing efficiency and mixing effect of the polymer materials, improving the construction of the fiber structure and the stability of the overall structure, and then evenly spreads the mixed materials on the bottom layer through the second roller group to facilitate production. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The present invention is a schematic diagram of the process of manufacturing a diaper absorbent core with a hot air skin-friendly layer.

[0034] Figure 2 The present invention is a schematic diagram of the cross-sectional structure of an absorbent core of a diaper absorbent core having a hot air skin-friendly layer according to the present invention.

[0035] Figure 3 The figure is a schematic diagram of the overall structure of a mixing device for raw materials of an absorbent core of the present invention.

[0036] Figure 4 The figure is a side structural schematic diagram of a mixing device for raw materials of an absorbent core according to the present invention.

[0037] Figure 5 A mixing device for raw materials of an absorbent core of the present invention Figure 4Schematic diagram of the AA cross-section structure.

[0038] Figure 6 This is a schematic diagram of the overall structure of a beating roller of a mixing device for raw materials of an absorbent core of the present invention.

[0039] Wherein: mixed fiber 1, hot air non-woven fabric 2, polymer material 3, bottom layer 4, coarse loosening equipment 5, fine loosening equipment 6, fiber storage tank 7, feeding device 8, crusher 9, feeding fan 10, feeding pipe 11, mixing equipment 12, oven 13, cooling box 14, upper air chamber 15, ventilation top cover 16, first roller group 17, polymer mixing chamber 18, polymer feeding group 19, second roller group 20, negative pressure air chamber 21, negative pressure lower air chamber 22, forming mesh belt 23, mesh belt deviation correction device 24, negative pressure device 25, stirring roller 26, with vertical seat bearing 27, stirring needle 28, pressing plate 29, sealing plate 30. DETAILED DESCRIPTION

[0040] The following describes the implementation methods of the present invention in conjunction with the accompanying drawings and related embodiments. It should be pointed out that the following related embodiments are only preferred embodiments for better illustrating the present invention itself, and the implementation methods of the present invention are not limited to the following embodiments, and the present invention relates to the relevant necessary components in this technical field, which should be regarded as the known technology in this technical field and can be known and mastered by the technical personnel in this technical field.

[0041] In the description of the present invention, it should be understood that the terms "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "inside" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the purpose of sub-describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention; in addition, the terms "primary" and "secondary" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features; therefore, it is defined that "primary" and "secondary" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly including one or more of the features.

[0042] Example 1 of manufacturing process of absorbent core:

[0043] like Figure 1 to Figure 2 As shown, a process for manufacturing a diaper absorbent core with a hot air skin-friendly layer comprises:

[0044] Step S1: low-melting-point fibers and plant fibers with a fiber length of 8-30 mm are pretreated to form mixed fibers 1 with a relative content of low-melting-point fibers of 10-40%, and the mixed fibers 1 are added to a mixing device 12 together with a polymer material 3, and are mixed and air-laid to form a composite;

[0045] The fiber length of the low-melting point fiber and the plant fiber is 8-30 mm. On the one hand, the length can ensure the amount of the polymer material 3, thereby ensuring the absorption capacity of the absorbent core. On the other hand, the melting point fiber of this length can well lock the polymer material 3, ensuring its stability and fluffiness, and will not be too long to cause excessive entanglement with the polymer material 3, affecting its fluffiness and being not conducive to water absorption, or too short to ensure the stability of the polymer material 3. Because the fiber length of the low-melting point fiber and the plant fiber is less than 8 mm, the polymer material 3 cannot be well locked due to insufficient limiting length, thereby affecting the overall stability of the absorbent core; the limiting length of the low-melting point fiber and the plant fiber is greater than 30 mm, the polymer material 3 will be locked excessively due to excessive fiber length, which is not conducive to the water absorption and expansion of the polymer material 3, thereby affecting the absorption capacity of the absorbent core. The relative content of the low-melting-point fiber in the mixed fiber is 10-40%, which can ensure its pulling force on the polymer material 3 and the strength of the absorbent core, while not occupying too much space of the polymer material 3, thereby ensuring the accommodation amount of the polymer material 3 and determining the water absorption capacity of the absorbent core.

[0046] The pre-processing in step S1 comprises the following steps:

[0047] Step a1: The low-melting point fibers and the plant fibers are both loosened by a rough loosening device 5 and stored in a fiber storage tank 7; wherein, the rough loosening is performed by a rough loosening mechanical device, such as a loosening roller with punching needles with large spacing, and the punching needles are used to loosen the low-melting point fibers and the plant fibers in large clumps into small clumps, so as to facilitate subsequent loosening, mixing and transportation.

[0048] Step a2: The low melting point fiber and the plant fiber are mixed in the fiber storage tank 7 by the fine loosening device 6 and then are taken to the crusher.

[0049] The mixed fiber 1 with a relative content of 10-40% of synthetic low-melting point fiber is transported to the mixing device 12 via the feeding fan 10 after mixing. The fine loosening is performed by a fine loosening mechanical device, such as a loosening roller with a small-spaced punching needle, and the punching needle is used to fully loosen the low-melting point fiber and the plant fiber in small balls into a fiber shape, so as to facilitate the subsequent mixing of the two.

[0050] The mixed air-laying in step S1 comprises the following steps:

[0051] Step b1: the mixed fiber 1 enters the mixing device 12 from the upper air chamber 15 at the upper end of the mixing device 12, is broken up by the first roller group 17 of the mixing device 12, and then falls into the polymer mixing chamber 18 of the mixing device 12;

[0052] Step b2: The polymer material 3 enters the polymer mixing chamber 18 through the polymer feeding group of the mixing device 12 and is mixed with the mixed fiber 1, and then is mixed and broken up by the second roller group 20 of the mixing device 12 to form a core mixed material; wherein, after the low-melting-point fiber and the plant fiber are mixed, they enter the mixing device 12 from the upper air chamber 15 at the upper end of the mixing device 12 through the feeding device 8 under the action of the feeding fan 10, and the mixed fiber 1 of the low-melting-point fiber and the plant fiber is further broken up and combed by the first roller group 17 to facilitate the subsequent mixing with the polymer material 3. At the same time, the broken fibers can be more intricate, thereby improving the locking ability of the mixed fiber 1 to the polymer material 3 and improving the stability of the overall structure.

[0053] Step b3: The core mixed material is dispersed and mixed and then falls into the negative pressure air chamber 21 of the mixing device 12, and is uniformly dropped on the forming mesh belt 23 covered with the composite bottom layer by the downward negative pressure wind force to form a composite body. Wherein, under the action of the negative pressure lower air chamber 22, the core mixed material is uniformly dropped on the forming mesh belt 23, and is composited with the composite bottom layer laid on the forming mesh belt 23 to form the composite body. The negative pressure lower air chamber 22 forms a downward negative pressure on the surface of the forming mesh belt 23 through the negative pressure device 25, so that the core mixed material is uniformly dropped on the forming mesh belt 23 after being dispersed and mixed by the second roller group 20. The composite bottom layer is a kind of non-woven fabric.

[0054] Step S2: After the composite comes out of the mixing device 12, a hot air nonwoven fabric 2 is laid on the surface thereof to form a core composite;

[0055] Step S3: The core composite body enters the oven 13 for hot air nonwoven fabric 2 bonding and drying, and is dried into an absorbent core body with a relative moisture content of 6-10%; wherein, the hot air nonwoven fabric 2 is laid on the composite body before drying, and does not need to be bonded by spraying glue on its surface, and the hot air nonwoven fabric 2 can be directly compounded with the composite body by heating, and the hot air nonwoven fabric 2 is bonded with the composite body through the oven 13 after being laid, and the oven 13 can melt the hot melt adhesive of the hot air nonwoven fabric 2 so as to bond with the composite body, and the overall process is more simplified, convenient for production, and saves production costs. The hot air nonwoven fabric 2 can be a prefabricated hot air nonwoven fabric or an online hot air nonwoven fabric.

[0056] Step S4: The absorbent core is cooled and shaped in the cooling box 14 and then rolled up.

[0057] As a further technical solution of the present invention, the temperature of the oven 13 in step S3 is 110-140°C.

[0058] The water content of the composite body after drying is lower than 10% of the national industry standard. The composite body is directly connected with the hot air non-woven fabric 2 by drying, which simplifies the bonding process between the surface layer and the composite body and reduces the production cost of the absorbent core body. The absorbent core body is finally cooled and shaped in a cooling box 14 and rolled up for standby use.

[0059] It should be noted that the present invention mixes the low-melting point fiber and the plant fiber, and is used to mix with the polymer material 3. The polymer material 3 is wrapped by the gaps between the mixed fibers 1, thereby fixing the polymer material 3 and stabilizing the structure. This is different from the traditional core structure. The traditional core structure is mostly achieved by digging holes in a thick layer of accommodation layer to accommodate the polymer material 3. The accommodation layer occupies a large space, which affects the capacity and fluffiness of the polymer material 3. At the same time, the hardness of the accommodation layer is relatively large. The present invention locks the polymer material 3 by the mixed fiber 1, which can reduce the volume occupied by the stable structure, can accommodate more of the polymer material 3, and improve the absorption capacity of the absorption core. At the same time, the mixed fiber 1 can improve the overall softness while ensuring the stability of the overall structure, making it more comfortable to use. The use of the hot air non-woven fabric 2 on the surface layer can simplify the surface layer bonding process and reduce the production cost of the absorption core.

[0060] Example 2 of the manufacturing process of the absorbent core:

[0061] like Figure 1 to Figure 2As shown, a manufacturing process of a diaper absorbent core with a hot air skin-friendly layer is basically the same as that of the first embodiment. In addition to being a single non-woven fabric, the composite layer used in step S1 can be formed by spreading mixed fibers 1 on the basis of the non-woven fabric in advance to form a diffusion layer, so that after the stool is absorbed, the diffusion layer formed by the mixed fibers 1 diffuses along the bottom layer 4 of the absorbent core with the absorption point as the center to the surroundings, thereby improving the absorption efficiency and diffusion efficiency of the absorbent core. The manufacturing steps of the composite bottom layer include:

[0062] Step c1: the pre-treated mixed fiber 1 with a fiber length of 8-30 mm enters the mixing device 12 from the upper air chamber 15 at the upper end of the mixing device 12, is broken up by the first roller group 17 of the mixing device 12, and then falls into the polymer mixing chamber 18 of the mixing device 12;

[0063] Step c2: The second roller group 20 mixes and breaks up the mixture, and then falls into the negative pressure air chamber 21 of the mixing device 12, and falls evenly on the forming mesh belt 23 covered with the bottom layer 4 by the downward negative pressure wind force to form a composite bottom layer.

[0064] Among them, the low-melting point fiber and the plant fiber of the same fiber length are loosened and mixed after the pretreatment of step S1, and further loosened and mixed by the first roller group 17 and the second roller group 20 of the mixing device 12, and then fall evenly onto the bottom layer 4 on the forming mesh belt 23 under the action of negative pressure, and are preliminarily compounded with the bottom layer 4 to form a composite bottom layer. The composite bottom layer includes the bottom layer 4 and the mixed fiber 1 layer, and the overall structure can be integrated through the bottom layer 4 and the hot air non-woven fabric 2. The mixed fiber 1 layer can make the fecal liquid diffuse and absorb rapidly from the bottom layer 4 to the surroundings, and the fiber filaments on the upper end surface formed by the mixed fiber 1 can be better connected with the core mixed material, making the overall structure more stable.

[0065] Mixing equipment for raw materials of absorbent core Example 1:

[0066] like Figures 1 to 6As shown, a mixing device for raw materials of an absorbent core comprises a mixing device 12 and a feeding device 8 and a negative pressure device 25 connected thereto, wherein the mixing device 12 comprises an upper air chamber 15, a first roller group 17, a polymer mixing chamber 18, a second roller group 20, a negative pressure air chamber 21, a negative pressure lower air chamber 22 and a forming mesh belt 23 arranged from top to bottom between the negative pressure air chamber 21 and the negative pressure lower air chamber 22, the upper end of the upper air chamber 15 is provided with a ventilation top cover 16 connecting the inside and outside of the mixing device 12, at least one fiber feed port is provided on the side wall of the upper air chamber 15 and connected to the feeding device 8, and at least one fiber feed port is provided between the upper air chamber 15 and the polymer mixing chamber 18 There is a first roller group 17, which includes at least two breaking rollers. At least one polymer feed port connected to the outside is provided on the side wall of the polymer mixing chamber 18, and the polymer feed port connects the polymer mixing chamber 18 and the polymer feed group 19. At least one second roller group 20 is provided between the negative pressure air chamber 21 and the polymer mixing chamber 18, and the second roller group 20 includes at least four breaking rollers. The forming mesh belt 23 is arranged around the negative pressure lower air chamber 22, and the lower end of the negative pressure lower air chamber 22 is provided with a mesh belt correction device 24 connected to the forming mesh belt 23, and the negative pressure lower air chamber 22 is provided with a negative pressure air port connected to the negative pressure device 25.

[0067] Among them, the mixing device 12 is connected through a cavity connected from top to bottom, and cooperates with the negative pressure device 25 to form a negative pressure mixing molding cavity with downward suction. The airflow can move the fiber and other materials downward, and then the first roller group 17 and the second roller group 20 are used to evenly break up and mix them, improve the degree of mixing, and under the action of suction and gravity, the mixed material is evenly adsorbed onto the forming mesh belt 23 to form a composite core. The whole process can highly mix the materials, and the natural downward movement can save production costs, and the combined process is simple and convenient for production. The mixing device 12 can comb and break up the fiber and other materials through the first roller group 17, improve the gap and connection between the materials, and facilitate mixing with the subsequent polymer material 3, so that the polymer material 3 can smoothly and evenly enter the gap between the fibers, thereby locking the polymer material, and after mixing, it is further mixed and broken up by the second roller group 20, so that it can evenly fall onto the composite bottom layer, avoiding the mixed fiber 1 and the polymer mixture from falling on the forming mesh belt 23 due to gravity.

[0068] As a further technical solution of the present invention, the feeding device 8 includes a crusher 9, a feeding pipe 11 connecting the crusher 9 and the fiber feeding port, and a feeding fan 10 provided at the lower end of the feeding pipe 11. The feeding device 8 is used for the pretreatment of step S1, mixing the low-melting-point fiber and the plant fiber.

[0069] As a further technical solution of the present invention, the breaking roller includes a cotton stirring roller 26, bearings 27 with vertical seats for fixing the cotton stirring roller 26 at both ends, and a number of cotton stirring needles 28 evenly arranged around the circumference of the cotton stirring roller 26, a pressure plate 29 is provided at the connection between the cotton stirring needles 28 and the cotton stirring roller 26, and sealing plates 30 are also provided at both ends of the cotton stirring roller 26.

[0070] As a further technical solution of the present invention, the length of the stirring needle 28 of the stirring roller 26 of the first roller group 17 is greater than the length of the stirring needle 28 of the stirring roller 26 of the second roller group 20.

[0071] The first roller group 17 and the second roller group 20 have the same working principle, and are both installed in the mixing device 12 through the vertical seat bearing 27. The mixing roller 26 drives the mixing needle 28 to break up the mixed fiber 1 and mix the mixed fiber 1 with the polymer material 3. The difference is that the mixing needle 28 of the mixing roller 26 is longer than the mixing needle 28 of the second roller group 20, so that the first roller group 17 is used for breaking up, and the second roller group 20 is used for breaking up and mixing. The sealing plate 30 is used to prevent the fiber from entering the rotating part of the mixing roller 26, which affects the service life of the mixing device 12.

[0072] Embodiment 2 of the mixing device for the raw materials of the absorbent core:

[0073] like Figures 1 to 6 As shown, a mixing device for raw materials of an absorbent core has a substantially consistent operating principle with the first embodiment of the mixing device 12, except that the first roller group 17 and the second roller group 20 of the mixing device 12 can have multiple layers of the stirring rollers 26. For example, the first roller group 17 is provided with two layers of stirring rollers 26 distributed vertically, so that the limited mixing and breaking can be broken in different directions, making the breaking and mixing more fully and uniformly.

[0074] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A process for manufacturing a diaper absorbent core with a hot air skin-friendly layer, characterized in that: include: Step S1: low-melting-point fibers and plant fibers with a fiber length of 8-30 mm are pretreated to form mixed fibers with a relative content of low-melting-point fibers of 10-40%, and the mixed fibers are added to a mixing device together with a polymer material, and after mixing, they are air-laid to form a composite; Step S2: After the composite comes out of the mixing device, a hot air non-woven fabric is laid on the surface thereof to form a core composite; Step S3: the core composite enters an oven for hot air nonwoven bonding and drying to form an absorbent core with a relative moisture content of 6-10%; Step S4: the absorbent core is cooled and shaped in a cooling box and then rolled up; The mixed air-laying in step S1 comprises the following steps: Step b1: the mixed fibers enter the mixing device from the upper wind chamber at the upper end of the mixing device, are broken up by the first roller group of the mixing device, and then fall into the polymer mixing chamber of the mixing device; Step b2: the polymer material enters the polymer mixing chamber through the polymer feeding group of the mixing device and is mixed with the mixed fibers, and then is mixed and broken up by the second roller group of the mixing device to form a core mixed material; Step b3: the core mixed material is dispersed and mixed and then falls into the negative pressure air cavity of the mixing equipment, and is evenly dropped onto the forming mesh belt covered with the composite bottom layer by the downward negative pressure wind force to form a composite body.

2. The process for manufacturing the absorbent core of a diaper having a hot air skin-friendly layer according to claim 1, characterized in that: The pre-processing in step S1 comprises the following steps: Step a1: the low melting point fiber and the plant fiber are loosened by a coarse loosening device and stored in a fiber storage tank; Step a2: The low melting point fiber and the plant fiber are taken from the fiber storage tank by a fine loosening device and then mixed in a crusher. The mixed fibers have a relative content of 10-40% of low melting point fibers. After mixing, the mixed fibers are conveyed to a mixing device via a feeding fan.

3. The process for manufacturing the absorbent core of a diaper having a hot air skin-friendly layer according to claim 1, characterized in that: The manufacturing process of the composite bottom layer in step b3 comprises the following steps: Step c1: the pre-treated mixed fibers with a fiber length of 8-30 mm enter the mixing device from the upper wind chamber at the upper end of the mixing device, are broken up by the first roller group of the mixing device, and then fall into the polymer mixing chamber of the mixing device; Step c2: The second roller group mixes and breaks up the mixture, and then falls into the negative pressure air chamber of the mixing device, and the downward negative pressure wind force evenly falls on the forming mesh belt covered with the bottom layer to form a composite bottom layer.

4. The process for manufacturing the absorbent core of a diaper having a hot air skin-friendly layer according to claim 1, characterized in that: The oven temperature in step S3 is 110-140°C.

5. A mixing device for raw materials of an absorbent core as claimed in any one of claims 1 to 4, comprising a mixing device and a feeding device and a negative pressure device connected thereto, characterized in that: The mixing equipment includes an upper air chamber, a first roller group, a polymer mixing chamber, a second roller group, a negative pressure air chamber, a negative pressure lower air chamber and a forming mesh belt arranged between the negative pressure air chamber and the negative pressure lower air chamber, the upper end of the upper air chamber is provided with a ventilation top cover connecting the inside and outside of the mixing equipment, at least one fiber feed port is provided on the side wall of the upper air chamber and is connected to a feeding device, at least one first roller group is provided between the upper air chamber and the polymer mixing chamber, the first roller group includes at least two breaking up rollers, at least one polymer feed port connected to the outside is provided on the side wall of the polymer mixing chamber, the polymer feed port connects the polymer mixing chamber and the polymer feeding group, at least one second roller group is provided between the negative pressure air chamber and the polymer mixing chamber, the second roller group includes at least four breaking up rollers, the forming mesh belt is arranged around the negative pressure lower air chamber, the lower end of the negative pressure lower air chamber is provided with a mesh belt correction device connected to the forming mesh belt, and the negative pressure lower air chamber is provided with a negative pressure air port connected to the negative pressure device.

6. The mixing device for raw materials of the absorbent core according to claim 5, characterized in that The feeding device comprises a crusher, a feeding pipe connecting the crusher and the fiber feeding port, and a feeding fan arranged at the lower end of the feeding pipe.

7. The mixing device for raw materials of the absorbent core according to claim 5, characterized in that The breaking roller includes a stirring roller, vertical seat bearings arranged at both ends of the stirring roller for fixing, and a plurality of stirring needles evenly arranged around the circumference of the stirring roller. A pressure plate is provided at the connection between the stirring needles and the stirring roller, and sealing plates are also provided at both ends of the stirring roller.

8. The mixing device for raw materials of the absorbent core according to claim 7, characterized in that The length of the stirring needle of the stirring roller of the first roller group is greater than the length of the stirring needle of the stirring roller of the second roller group.

9. The mixing device for raw materials of the absorbent core according to claim 7, characterized in that: When the number of the first roller group and the second roller group is greater than two, the cotton stirring rollers in each roller group are arranged vertically.

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