A comfortable medical nursing pad with a multi-layer structure and its preparation process

Abstract

The present invention discloses a comfortable medical nursing pad with a multi-layer structure and its preparation process, which relates to the field of sanitary products. The nursing pad includes: a top layer, where the top layer is a skin-friendly layer made of non-woven fabric material; a composite core layer, where the composite core layer is a conforming water absorption and diffusion layer, including a support structure of three-dimensional porous material, a cellulose gel structure embedded on the three-dimensional porous material, and a fluff pulp fiber structure mixed in the three-dimensional porous material; a bottom layer, where the bottom layer is an anti-permeation and breathable layer made of polyethylene film material. By using the three-dimensional porous material as the support structure of the composite core layer and embedding the cellulose gel structure, it can quickly absorb and retain a large amount of liquid, form a gel-like substance, effectively lock the liquid to prevent backflow, and at the same time mix the fluff pulp fiber structure, which can achieve a dynamic balance of liquid absorption, diffusion and storage, thereby improving the overall absorption efficiency and comfort.

Description

Technical Field

[0001] The present invention relates to the technical field of sanitary products, and particularly relates to a comfortable medical nursing pad with a multi-layer structure and a preparation process thereof. Background Art

[0002] As an important auxiliary product in medical care, nursing pads are widely used in various scenarios such as patient care, surgical assistance, wound care, etc. Their main functions are to absorb and isolate body fluids, keep the patient's skin dry, reduce the risk of skin infection, and at the same time facilitate the nursing operations of medical staff. Their design and preparation process are directly related to the patient's use experience and nursing effect.

[0003] Traditional nursing pads usually use simple cotton fibers or ordinary non-woven fabrics as the main materials. Their absorption capacity is relatively weak, unable to quickly absorb a large amount of body fluids, and prone to liquid backflow, making the patient's skin stay wet for a long time, increasing the risk of skin damage and infection.

[0004] Therefore, it is necessary to improve the deficiencies in the prior art to solve the above problems. Summary of the Invention

[0005] The present invention overcomes the deficiencies of the prior art and provides a comfortable medical nursing pad with a multi-layer structure and a preparation process thereof.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a comfortable medical nursing pad with a multi-layer structure, which successively includes from top to bottom:

[0007] A top layer, where the top layer is a skin-friendly layer made of non-woven fabric material;

[0008] A composite core layer, where the composite core layer is a conforming water absorption and diffusion layer, including a support structure of three-dimensional porous material, a cellulose gel structure embedded on the three-dimensional porous material, and a fluff pulp fiber structure mixed in the three-dimensional porous material;

[0009] A bottom layer, where the bottom layer is an anti-permeation and breathable layer made of polyethylene film material.

[0010] In a preferred embodiment of the present invention, the thickness of the top layer is 0.1 - 0.3 mm; the thickness of the composite core layer is 1 - 3 mm; the thickness of the bottom layer is 0.02 - 0.05 mm.

[0011] The present invention provides a preparation process for a comfortable medical nursing pad with a multi-layer structure, including the following steps:

[0012] S1. Dissolve the biobased polymer material in water to obtain a biobased polymer colloidal solution with a certain concentration. After pretreatment at low temperature, obtain a biobased polymer porous material by freeze-drying, and form a biobased polymer calcium porous material through calcium salt replacement treatment;

[0013] S2. Immerse the biobased polymer calcium porous material in a surfactant, and after pretreatment at low temperature, obtain a flexible biobased polymer calcium porous material by freeze-drying;

[0014] S3. Ultrasonically treat a cellulose fiber suspension with a certain concentration. Dissolve an oxidant in water to obtain an oxidant solution with a certain concentration, and add it to the ultrasonically treated cellulose fiber suspension. Adjust the pH to 4 - 5 and stir once, then add ethylene glycol and stir twice. After dialysis in water, obtain aldehyde-functionalized cellulose fibers by freeze-drying;

[0015] S4. Stir and mix an aldehyde-functionalized cellulose fiber solution and a carboxymethyl chitosan solution, centrifuge, and let it stand in a constant temperature incubator to form a cellulose gel;

[0016] S5. Stir the flexible biobased polymer calcium porous material and the cellulose gel evenly, ultrasonically treat them, and fully mix them with fluff pulp fibers, then spread them into a web to obtain a composite core layer;

[0017] S6. Use a polyethylene film as the bottom layer and a non-woven fabric as the top layer, place them at the bottom and top of the composite core layer respectively for thermocompression lamination, and then cut to obtain a comfortable medical nursing pad with a multi-layer structure.

[0018] In a preferred embodiment of the present invention, in the step of S1, the biobased polymer material is one of sodium alginate or polylactic acid; the concentration of the biobased polymer colloidal solution is 1.5 - 3 wt%; the temperature of the pretreatment is -5 to -15 °C, and the time is 20 - 24 h; the temperature of the freeze-drying is -30 to -50 °C, and the time is 24 - 48 h.

[0019] In a preferred embodiment of the present invention, in the step of S1, the replacement treatment specifically includes the following steps:

[0020] Immerse the sodium alginate porous material in a 2 - 5 wt% calcium chloride / ethanol solution at room temperature for 4 - 8 h, and dry it to constant weight at 70 - 80 °C to obtain a calcium alginate porous material, where the mass ratio of the sodium alginate porous material to the calcium chloride / ethanol solution is 1:3 - 6.

[0021] In a preferred embodiment of the present invention, in the step of S1, the replacement treatment specifically includes the following steps:

[0022] The polylactic acid porous material is treated in a sodium hydroxide solution with a concentration of 8-15 wt% at a temperature of 80-100 °C for 6-12 h to obtain sodium lactate. Sodium lactate and calcium chloride with a molar ratio of 2:1 are magnetically stirred at room temperature for 1-2 h and then centrifuged to obtain a calcium lactate porous material. Among them, the mass ratio of the polylactic acid porous material to the sodium hydroxide solution is 1:4-8.

[0023] In a preferred embodiment of the present invention, in the step of S2, the surfactant is one of glycerol or glycerol random polyether; the soaking time is 2-3 h; the temperature of the pretreatment is -5 to -15 °C, and the time is 20-24 h; the temperature of the freeze-drying is -30 to -50 °C, and the time is 24-48 h; the mass ratio of the bio-based polymer calcium porous material to the surfactant is 1:3-8.

[0024] In a preferred embodiment of the present invention, in the step of S3, the cellulose fiber is one of nanofibrillated cellulose or bamboo charcoal fiber, and the concentration of the cellulose fiber suspension is 0.8-1.5 wt%; the power of the ultrasonic treatment is 1-3 W / cm 2 , and the time is 1-3 h; the oxidant is one of potassium permanganate or sodium periodate, and the concentration of the oxidant solution is 10-15 wt%; the time of the first stirring is 3-6 h, and the time of the second stirring is 20-50 min; the temperature of the freeze-drying is -30 to -50 °C, and the time is 24-48 h; the mass ratio of the cellulose fiber suspension, the oxidant solution and the ethylene glycol is 1:0.1-0.3:0.07-0.12.

[0025] In a preferred embodiment of the present invention, in the step of S4, the concentration of the aldehyde-functionalized cellulose fiber solution is 0.8-1.5 wt%, the concentration of the carboxymethyl chitosan solution is 2-5 wt%, and the mass ratio of the aldehyde-functionalized cellulose fiber solution to the carboxymethyl chitosan solution is 1:1; the centrifugation time is 20-40 min; the temperature of the static treatment is 35-50 °C, and the time is 20-25 h.

[0026] In a preferred embodiment of the present invention, in the step of S5, the mass ratio of the flexible bio-based polymer calcium porous material, the cellulose gel and the fluff pulp fiber is 1:0.08-0.16:0.6-0.8; the power of the ultrasonic treatment is 1-3 W / cm 2 , and the time is 15-30 min.

[0027] The present invention solves the defects in the background technology and has the following beneficial effects:

[0028] The present invention provides a comfortable medical nursing pad with a multi-layer structure. By using a three-dimensional porous material as the support structure of the composite core layer and embedding a cellulose gel structure, its specific surface area is significantly increased. When liquid contacts the top layer, it allows the liquid to quickly penetrate and disperse, reducing the accumulation of surface liquid, and can quickly absorb and retain a large amount of liquid, forming a gel-like substance, effectively locking the liquid to prevent backflow, keeping the pad surface dry. At the same time, the mixed fluff pulp fiber structure can combine to form a hierarchical pore system of micro-pores and macro-pores, using capillary action to accelerate the lateral diffusion of the liquid, relieve the swelling pressure of the cellulose gel, prevent local saturation, and achieve a dynamic balance of liquid absorption, diffusion, and storage, thereby improving the overall absorption efficiency and comfort, avoiding the patient's skin being in a wet state for a long time, and reducing the risk of skin damage and infection.

[0029] In the preparation process of the present invention, by using a calcium salt to crosslink a bio-based polymer material to construct a high-strength porous framework and using a surfactant, flexible treatment of the material is achieved, enabling it to have certain water absorption performance while improving the flexibility and elasticity of the material, increasing the conformability and shape retention performance. At the same time, in cooperation with the embedded cellulose gel, it can absorb exudate to form a hydrogel phase, effectively locking the liquid to prevent backflow, further enhancing the water absorption effect of the nursing pad. Moreover, the mixed fluff pulp fiber can improve the diffusion effect of the liquid phase, prevent local swelling saturation, and achieve a dynamic balance of liquid absorption, diffusion, and storage, enabling it to have excellent water absorption rate and water absorption effect, thus achieving better use comfort.

[0030] In the preparation process of the present invention, through precise control of the ultrasonic treatment time during the compounding of the core layer material, the full stretching of molecular chains and the stability of the dynamic crosslinking network can be achieved, making the molecular chains more dispersed and uniform, which helps to increase the specific surface area and porosity of the material, thereby improving the water absorption rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings;

[0032] Figure 1 is the overall separation structure diagram of the preferred embodiment of the present invention;

[0033] Figure 2 is the schematic diagram of the composite core layer structure of the preferred embodiment of the present invention;

[0034] In the figure: 1. Top layer; 2. Composite core layer; 21. Support structure; 22. Cellulose gel structure; 23. Fluff pulp fiber structure; 3. Bottom layer. Detailed implementation manners

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0036] Many specific details are set forth in the following description in order to provide a thorough understanding of the present invention. However, the present invention may be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0037] As Figure 1 and Figure 2 shown, a comfortable medical nursing pad with a multi-layer structure includes, from top to bottom in sequence: a top layer 1, where the top layer 1 is a skin-friendly layer made of non-woven fabric material; a composite core layer 2, where the composite core layer 2 is a conforming water absorption and diffusion layer, including a support structure 21 of a three-dimensional porous material, a cellulose gel structure 22 embedded in the three-dimensional porous material, and a fluff pulp fiber structure 23 mixed in the three-dimensional porous material; a bottom layer 3, where the bottom layer 3 is an anti-permeation and gas-permeable layer made of polyethylene film material.

[0038] It should be noted that the thickness of the top layer 1 is 0.1 - 0.3 mm; the thickness of the composite core layer 2 is 1 - 3 mm; the thickness of the bottom layer 3 is 0.02 - 0.05 mm; through the top layer 1 made of non-woven fabric material, the friction between the skin and the nursing pad can be effectively reduced, providing a comfortable use experience, while allowing the skin to maintain a certain breathability and reducing the sense of dampness; the bottom layer 3 made of polyethylene film material can ensure that the liquid absorbed by the composite core layer 2 will not leak onto the mattress or clothing, keeping the environment clean and dry; the composite core layer 2 uses a three-dimensional porous material as the support structure 21, its specific surface area is significantly increased, providing good liquid diversion channels and storage spaces, allowing the liquid to quickly penetrate and disperse, reducing the accumulation of surface liquid, improving the absorption efficiency, and at the same time, the cellulose gel structure 22 embedded on the support structure 21 has excellent liquid absorption capacity, can quickly absorb and retain a large amount of liquid, form a gel-like substance, effectively lock the liquid to prevent backflow, keep the pad surface dry, and the fluff pulp fiber structure 23 mixed in the three-dimensional porous material has good inter-fiber voids, enabling it to combine to form a hierarchical pore system of micropores and macropores, using capillary action to accelerate the lateral diffusion of the liquid, relieve the swelling pressure of the cellulose gel, prevent local saturation, and achieve a dynamic balance of liquid absorption, diffusion and storage, thereby improving the overall absorption efficiency and comfort level.

[0039] A preparation process of a comfortable medical nursing pad with a multi-layer structure includes the following steps:

[0040] S1. Dissolve the bio-based polymer material in water to obtain a bio-based polymer colloidal solution with a certain concentration. After pretreatment at low temperature, obtain a bio-based polymer porous material through freeze-drying, and through calcium salt replacement treatment, form a bio-based polymer calcium porous material;

[0041] S2. Immerse the bio-based polymer calcium porous material in a surfactant, after pretreatment at low temperature, obtain a flexible bio-based polymer calcium porous material through freeze-drying;

[0042] S3. Ultrasonically treat a cellulose fiber suspension with a certain concentration. Dissolve an oxidant in water to obtain an oxidant solution with a certain concentration, and add it to the ultrasonically treated cellulose fiber suspension. Adjust the pH to 4 - 5 for the first stirring, add ethylene glycol for the second stirring, after dialysis in water, obtain aldehyde-functionalized cellulose fibers through freeze-drying;

[0043] S4. Stir and mix the aldehyde-functionalized cellulose fiber solution and the carboxymethyl chitosan solution, centrifuge, and let it stand in an incubator at a constant temperature to form a cellulose gel;

[0044] S5. Stir the flexible bio-based polymer calcium porous material and the cellulose gel evenly, ultrasonically treat, and fully mix with fluff pulp fibers, and spread them into a web to obtain the composite core layer 2;

[0045] S6. Take the polyethylene film as the bottom layer 3 and the non-woven fabric as the top layer 1, place them at the bottom and top of the composite core layer 2 respectively, and perform hot pressing and lamination, then cut to obtain a comfortable medical nursing pad with a multi-layer structure.

[0046] It should be noted that the raw materials, equipment, reagents, etc. used in the present invention can all be obtained through market purchase or by means of preparation in the prior art.

[0047] In some specific embodiments, in the step of S1, the bio-based polymer material is one of sodium alginate or polylactic acid; the concentration of the bio-based polymer colloidal solution is 1.5 - 3 wt%; the temperature of the pretreatment is -5 to -15 °C, and the time is 20 - 24 h; the temperature of the freeze-drying is -30 to -50 °C, and the time is 24 - 48 h.

[0048] In some specific embodiments, in the step of S1, the replacement treatment specifically includes the following steps:

[0049] Immerse the sodium alginate porous material in a 2 - 5 wt% calcium chloride / ethanol solution at room temperature for 4 - 8 h, and dry it to constant weight at 70 - 80 °C to obtain a calcium alginate porous material, wherein the mass ratio of the sodium alginate porous material to the calcium chloride / ethanol solution is 1:3 - 6.

[0050] In some specific embodiments, in the step of S1, the replacement treatment specifically includes the following steps:

[0051] Immerse the polylactic acid porous material in an 8 - 15 wt% sodium hydroxide solution at a temperature of 80 - 100 °C for 6 - 12 h to obtain sodium lactate, and magnetically stir the sodium lactate and calcium chloride with a molar ratio of 2:1 at room temperature for 1 - 2 h, then centrifuge to obtain a calcium lactate porous material, wherein the mass ratio of the polylactic acid porous material to the sodium hydroxide solution is 1:4 - 8.

[0052] In some specific embodiments, in the step of S2, the surfactant is one of glycerol or glycerol random polyether; the soaking time is 2 - 3 h; the temperature of the pretreatment is -5 to -15 °C, and the time is 20 - 24 h; the temperature of the freeze-drying is -30 to -50 °C, and the time is 24 - 48 h; the mass ratio of the bio-based polymer calcium porous material to the surfactant is 1:3 - 8.

[0053] In some specific embodiments, in the step of S3, the cellulose fiber is one of nano-cellulose fiber or bamboo charcoal fiber, and the concentration of the cellulose fiber suspension is 0.8 - 1.5 wt%; the power of the ultrasonic treatment is 1 - 3 W / cm 2, the time is 1 to 3 h; the oxidant is one of potassium permanganate or sodium periodate, and the concentration of the oxidant solution is 10 to 15 wt%; the time of the first stirring is 3 to 6 h, and the time of the second stirring is 20 to 50 min; the temperature of freeze-drying is -30 to -50 °C, and the time is 24 to 48 h; the mass ratio of the cellulose fiber suspension, the oxidant solution and ethylene glycol is 1:0.1 to 0.3:0.07 to 0.12.

[0054] In some specific embodiments, in the step of S4, the concentration of the aldehyde group-modified cellulose fiber solution is 0.8 to 1.5 wt%, the concentration of the carboxymethyl chitosan solution is 2 to 5 wt%, and the mass ratio of the aldehyde group-modified cellulose fiber solution to the carboxymethyl chitosan solution is 1:1; the centrifugation time is 20 to 40 min; the temperature of the static treatment is 35 to 50 °C, and the time is 20 to 25 h.

[0055] In some specific embodiments, in the step of S5, the mass ratio of the flexible bio-based polymer calcium porous material, the cellulose gel and the fluff pulp fiber is 1:0.08 to 0.16:0.6 to 0.8; the power of the ultrasonic treatment is 1 to 3 W / cm 2 , and the time is 15 to 30 min.

[0056] To further make the object and effect of the present invention simple and easy to understand, the present invention is further elaborated in combination with the following specific examples and comparative examples. Example 1

[0057] A preparation process of a multi-layer structured comfortable medical nursing pad includes the following steps:

[0058] S1. Dissolve sodium alginate in water to obtain a sodium alginate colloidal solution with a concentration of 2 wt%. At -15 °C, perform freeze pretreatment for 24 h, and at -35 °C, perform freeze-drying for 48 h to obtain a sodium alginate porous material. Then, soak the sodium alginate porous material in a 3 wt% calcium chloride / ethanol solution at room temperature for 6 h, and dry it to constant weight at 80 °C to obtain a calcium alginate porous material. Among them, the mass ratio of the sodium alginate porous material to the calcium chloride / ethanol solution is 1:5;

[0059] S2. Soak the calcium alginate porous material in glycerol for 3 h, perform freeze pretreatment at -15 °C for 24 h, and perform freeze-drying at -35 °C for 48 h to obtain a flexible calcium alginate porous material. Among them, the mass ratio of the calcium alginate porous material to glycerol is 1:6;

[0060] S3. Use a 1 wt% bamboo charcoal fiber suspension at 1 W / cm 2The power was adjusted to perform ultrasonic treatment for 2 h. Potassium permanganate was dissolved in water to obtain a potassium permanganate solution with a concentration of 12 wt%, which was then added to the ultrasonically treated bamboo charcoal fiber suspension. The pH was adjusted to 4.5 and stirred for 4 h. Ethylene glycol was added and stirred for 30 min. After dialysis in water, it was freeze-dried at -40 °C for 24 h to obtain aldehyde-functionalized bamboo charcoal fibers. Among them, the mass ratio of the bamboo charcoal fiber suspension, potassium permanganate solution, and ethylene glycol was 1:0.2:0.08;

[0061] S4. Equal volumes of an aldehyde-functionalized bamboo charcoal fiber solution with a concentration of 1.2 wt% and a carboxymethyl chitosan solution with a concentration of 3 wt% were stirred and mixed, centrifuged for 30 min, and then left to stand in a constant-temperature incubator at 45 °C for 20 h to form a bamboo charcoal cellulose gel;

[0062] S5. The flexible calcium alginate porous material and the bamboo charcoal cellulose gel were stirred evenly, and ultrasonic treatment was performed at a power of 2 W / cm 2 for 20 min and then thoroughly mixed with fluff pulp fibers. The mass ratio of the flexible calcium alginate porous material, bamboo charcoal cellulose gel, and fluff pulp fibers was 1:0.11:0.7. They were spread into a web to obtain the composite core layer 2;

[0063] S6. A polyethylene film was used as the bottom layer 3, and a non-woven fabric was used as the top layer 1. They were respectively placed at the bottom and top of the composite core layer 2 and hot-pressed and laminated at 110 °C for 1.5 s, and then cut into 80*90 cm to obtain a comfortable medical nursing pad with a multi-layer structure where the thickness of the top layer 1 was 0.1 mm; the thickness of the composite core layer 2 was 2 mm; and the thickness of the bottom layer 3 was 0.04 mm. Example 2

[0064] This example was basically the same as Example 1, except that the bio-based polymer material was polylactic acid. The specific steps of S1 were as follows: Polylactic acid was dissolved in water to obtain a polylactic acid colloidal solution with a concentration of 2 wt%. It was pretreated by freeze-drying at -15 °C for 24 h and then freeze-dried at -35 °C for 48 h to obtain a polylactic acid porous material. The polylactic acid porous material was treated in an 8 wt% sodium hydroxide solution at 80 °C for 8 h to obtain sodium lactate. Sodium lactate and calcium chloride with a molar ratio of 2:1 were magnetically stirred at room temperature for 2 h and then centrifuged to obtain a calcium lactate porous material. Among them, the mass ratio of the polylactic acid porous material to the sodium hydroxide solution was 1:6. Example 3

[0065] This example was basically the same as Example 1, except that in the steps of S5, the mass ratio of the flexible calcium alginate porous material, bamboo charcoal cellulose gel, and fluff pulp fibers was 1:0.16:0.6. Example 4

[0066] This example is basically the same as Example 1, except that: in step S5, the mass ratio of the flexible calcium alginate porous material, bamboo charcoal cellulose gel and fluff pulp fiber is 1:0.08:0.8. Example 5

[0067] This example is basically the same as Example 1, except that: in step S5, the ultrasonic treatment time is 15 min. Example 6

[0068] This example is basically the same as Example 1, except that: in step S5, the ultrasonic treatment time is 30 min.

[0069] Comparative Example 1

[0070] Commercially available: Linyi Yunlu Biotechnology Co., Ltd. - Adult Care Pad with model number YXR—CRHLD; The main components include: the top layer is composed of non-woven fabric, the core layer is composed of fluff pulp and superabsorbent polymer (SAP), and the bottom layer is composed of PE film; The size is 80*90 cm, the thickness of the top layer is 0.1 mm; The thickness of the composite core layer is 2 mm; The thickness of the bottom layer is 0.04 mm.

[0071] Comparative Example 2

[0072] This comparative example is basically the same as Example 1, except that: there are no steps S3 and S4, and step S5 is specifically: fully mixing the flexible calcium alginate porous material and fluff pulp fiber, where the mass ratio of the flexible calcium alginate porous material and fluff pulp fiber is 1:0.7, spreading it into a net to obtain the composite core layer 2.

[0073] Comparative Example 3

[0074] This comparative example is basically the same as Example 1, except that: step S5 is specifically: stirring the flexible calcium alginate porous material and bamboo charcoal cellulose gel evenly, with a power of 2 W / cm 2 for 20 min, where the mass ratio of the flexible calcium alginate porous material and bamboo charcoal cellulose gel is 1:0.11, spreading it into a net to obtain the composite core layer 2.

[0075] Comparative Example 4

[0076] This comparative example is basically the same as Example 1, except that: in step S5, the mass ratio of the flexible calcium alginate porous material, bamboo charcoal cellulose gel and fluff pulp fiber is 1:0.05:0.7.

[0077] Comparative Example 5

[0078] This comparative example is basically the same as Example 1, except that: in the step of S5, the mass ratio of the flexible calcium alginate porous material, bamboo charcoal cellulose gel and fluff pulp fiber is 1:0.19:0.7.

[0079] Comparative Example 6

[0080] This comparative example is basically the same as Example 1, except that: in the step of S5, the mass ratio of the flexible calcium alginate porous material, bamboo charcoal cellulose gel and fluff pulp fiber is 1:0.11:0.5.

[0081] Comparative Example 7

[0082] This comparative example is basically the same as Example 1, except that: in the step of S5, the mass ratio of the flexible calcium alginate porous material, bamboo charcoal cellulose gel and fluff pulp fiber is 1:0.11:1.

[0083] Comparative Example 8

[0084] This comparative example is basically the same as Example 1, except that: in the step of S5, the ultrasonic treatment time is 10 min.

[0085] Comparative Example 9

[0086] This comparative example is basically the same as Example 1, except that: in the step of S5, the ultrasonic treatment time is 35 min.

[0087] Performance detection: The medical nursing pads prepared in Examples 1-6 and Comparative Examples 1-9 were tested for absorption rate, and the results are shown in Table 1.

[0088] Absorption rate test: Referring to ISO 15226-1 "Test Method for Absorbency of Disposable Absorbent Products", a measuring cylinder with a capacity of 500 mL was placed in the middle of the nursing pad, and 300 mL of artificial urine was poured in, and the time required for the liquid to be completely absorbed by the nursing pad was recorded.

[0089] Table 1: Performance test results

[0090]

[0091] It can be seen from Table 1 that:

[0092] It can be seen from the comparison between Example 1 and Comparative Example 1 that by using a calcium salt to crosslink a bio-based polymer material to construct a high-strength porous skeleton and adopting a surfactant, the flexible treatment of the material is realized, so that while the material has certain water absorption performance, the flexibility and elasticity of the material are improved, the conformability and shape retention performance are increased. At the same time, in cooperation with the embedded cellulose gel, it can absorb exudate to form a hydrogel phase, effectively lock the liquid to prevent back-leakage, further enhance the water absorption effect of the nursing pad, and the mixed fluff pulp fibers can improve the diffusion effect of the liquid phase, prevent local swelling saturation, and achieve a dynamic balance of liquid absorption, diffusion and storage, so that it has excellent water absorption rate and water absorption effect, thus achieving better use comfort. However, for traditional nursing pads, the SAP particles rely on physical adsorption to lock the liquid. After absorbing the liquid, the particles are prone to agglomerate to form a gel barrier, which hinders the liquid diffusion, thereby reducing the water absorption rate and effect.

[0093] It can be seen from the comparison between Example 1 and Example 2 that the bamboo charcoal cellulose gel forms a dynamic cross-linked network through the Schiff base reaction of aldehyde group-modified cellulose and carboxymethyl chitosan. The hydrogen bonds and covalent bonds in this network can simultaneously bind water molecules to form a stable hydrogel phase, lock the liquid and prevent back-leakage; and the fluff pulp fibers used and the skeleton constructed by the three-dimensional porous material form a macro-micro hierarchical structure, and the liquid diffusion is accelerated through the capillary gradient effect; it can be seen from the comparison between Example 1 and Comparative Example 2 that when the bamboo charcoal cellulose gel is removed, the molecular-level water locking mechanism of the bamboo charcoal cellulose gel is lost, resulting in a decrease in the liquid retention ability and a reduction in the liquid absorption efficiency; it can be seen from the comparison between Example 1 and Comparative Example 3 that after removing the fluff pulp fibers, there are only macro-pores in the pore scale, and the lateral liquid diffusion rate decreases, resulting in a decrease in the liquid diffusion effect, thereby reducing the liquid absorption rate and effect.

[0094] It can be seen from the comparison between Example 1, Example 3 and Example 4 and Comparative Examples 4-7 that appropriate contents of flexible calcium alginate porous material, bamboo charcoal cellulose gel and fluff pulp fibers can maintain excellent liquid absorption rate and effect; among them, the bamboo charcoal cellulose gel forms a dynamic cross-linked network through aldehyde groups and carboxymethyl chitosan. When the ratio is unbalanced, excessive gel will overfill the pores of the calcium alginate porous skeleton, resulting in a decrease in pore connectivity, a weakening of capillary force, a limitation of the swelling freedom of the material, and when it is too low, the density of the dynamic cross-linked network is too low to effectively lock the liquid through the cooperation of hydrogen bonds and covalent bonds. The three-dimensional porous skeleton lacks gel support and is prone to pore collapse due to uneven swelling pressure after absorbing liquid, blocking the liquid diffusion path and affecting the water absorption effect; at the same time, excessive fluff pulp fibers will occupy the macro-pore space, resulting in the failure of the macro-micro hierarchical system, the disappearance of the capillary gradient effect, and a decrease in the lateral liquid diffusion rate. Too low a ratio leads to insufficient diffusion channels, and the diffusion of the liquid in the composite core layer is limited, making it difficult to maintain pore stability and the dynamic balance of liquid absorption.

[0095] It can be known from the comparison between Example 1, Example 5 and Example 6 and Comparative Example 8 and Comparative Example 9 that by precisely controlling the ultrasonic treatment time during the compounding of the core layer material, the full stretching of molecular chains and the stability of the dynamic crosslinking network can be achieved, making the molecular chains more dispersed and uniform, which helps to increase the specific surface area and porosity of the material, thereby improving the water absorption rate; when the ultrasonic time is too short, the molecular chains are not fully stretched, resulting in local agglomeration and a decrease in pore connectivity. At the same time, too long ultrasonic time is likely to cause the molecular chains inside the material to break and damage the pore structure inside the material, making it uneven or blocked, thus reducing the water absorption rate and effect.

[0096] Based on the ideal embodiments of the present invention as inspiration, through the above description, for those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be encompassed by the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

[0097] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A multi-layered comfortable medical nursing pad, characterized in that: From top to bottom, they include: A top layer, wherein the top layer is a skin-friendly layer and is made of a non-woven fabric material; A composite core layer, wherein the composite core layer is a water-absorbing and diffusing layer, comprising a support structure of a three-dimensional porous material, a cellulose gel structure embedded in the three-dimensional porous material, and a fluff pulp fiber structure mixed in the three-dimensional porous material; A bottom layer, wherein the bottom layer is an air-impermeable layer and is made of a polyethylene film material; The preparation process of the nursing pad comprises the following steps: S1, dissolving the bio-based polymer material in water to obtain a bio-based polymer colloidal solution with a concentration of 1.5-3 wt%, pre-treating the solution at low temperature, freeze-drying the solution to obtain a bio-based polymer porous material, and performing calcium salt replacement treatment to form a bio-based polymer calcium porous material; S2, soaking the bio-based polymer calcium porous material in a surfactant, pre-treating it at low temperature, and then freeze-drying it to obtain a flexible bio-based polymer calcium porous material; S3, treating a cellulose fiber suspension having a concentration of 0.8-1.5 wt %, dissolving an oxidant in water to obtain an oxidant solution having a concentration of 10-15 wt %, adding the oxidant solution to the cellulose fiber suspension after the ultrasonic treatment, adjusting the pH to 4-5 and stirring once, adding ethylene glycol and stirring twice, dialyzing in water, and freeze-drying to obtain aldehyded cellulose fibers; S4, mixing the aldehyded cellulose fiber solution and the carboxymethyl chitosan solution, centrifuging, and standing in a constant temperature incubator to form a cellulose gel; S5, stirring the flexible bio-based macromolecular calcium porous material and the cellulose gel evenly, ultrasonically treating them, and fully mixing them with the fluff pulp fibers, spreading them into a web, and obtaining a composite core layer; S6, placing a polyethylene film as a bottom layer and a non-woven fabric as a top layer, respectively, on the bottom and top of the composite core layer for hot pressing and compounding, and cutting to obtain a multi-layer structured comfortable medical nursing pad; The mass ratio of the flexible bio-based macromolecular calcium porous material, the cellulose gel and the fluff pulp fiber is 1:0.08-0.16:0.6-0.8; In step S1, the bio-based polymer material is one of sodium alginate or polylactic acid; When the bio-based polymer material is sodium alginate, the replacement treatment specifically comprises the following steps: soaking the sodium alginate porous material in a 2-5 wt% calcium chloride / ethanol solution at room temperature for 4-8 h, and drying at 70-80° C. to constant weight to obtain a calcium alginate porous material; When the bio-based polymer material is polylactic acid, the replacement treatment specifically includes the following steps: treating the polylactic acid porous material in an 8-15 wt% sodium hydroxide solution at a temperature of 80-100°C for 6-12 h to obtain sodium lactate, and magnetically stirring sodium lactate and calcium chloride in a molar ratio of 2:1 at room temperature for 1-2 h, and centrifuging to obtain a calcium lactate porous material.

2. A multi-layered comfortable medical nursing pad according to claim 1, characterized in that: The thickness of the top layer is 0.1-0.3 mm; the thickness of the composite core layer is 1-3 mm; and the thickness of the bottom layer is 0.02-0.05 mm.

3. A multi-layered comfortable medical nursing pad according to claim 1, characterized in that: In step S1, the pretreatment temperature is -5 to -15°C for 20 to 24 h; the freeze-drying temperature is -30 to -50°C for 24 to 48 h.

4. The multi-layer comfortable medical nursing pad according to claim 1, characterized in that: In the step S2, the surfactant is one of glycerol or glycerol random polyether; the soaking time is 2 to 3 hours; the pretreatment temperature is -5 to -15 ° C, and the time is 20 to 24 hours; the freeze-drying temperature is -30 to -50 ° C, and the time is 24 to 48 hours.

5. The multi-layer comfortable medical nursing pad according to claim 1, characterized in that: In the step S3, the cellulose fiber is one of nanocellulose fiber and bamboo charcoal fiber; the power of the ultrasonic treatment is 1-3 W / cm 2 , time is 1~3 h; the oxidant is one of potassium permanganate or sodium periodate; the time of the first stirring is 3~6 h, the time of the second stirring is 20~50 min; the temperature of the freeze-drying is -30~-50 ℃, and the time is 24~48 h.

6. The multi-layer comfortable medical nursing pad according to claim 1, characterized in that: In the step S4, the concentration of the aldehyded cellulose fiber solution is 0.8-1.5 wt %, the concentration of the carboxymethyl chitosan solution is 2-5 wt %, and the mass ratio of the aldehyded cellulose fiber solution to the carboxymethyl chitosan solution is 1:1; the centrifugation time is 20-40 min; the temperature of the static treatment is 35-50 ° C, and the time is 20-25 h.

7. The multi-layer comfortable medical nursing pad according to claim 1, characterized in that: In the step S5, the power of the ultrasonic treatment is 1-3 W / cm 2 , time is 15~30 min.

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