Preparation method of medical dialyzing paper

Abstract

The invention provides a preparation method of medical dialyzing paper, which comprises the following steps: step 1, respectively pulping plant fibers and regenerated fibers to obtain plant fiber pulp and regenerated fiber pulp; 2, the plant fiber pulp and the regenerated fiber pulp are mixed, an antibacterial agent, a wet strength agent and a reinforcing agent are sequentially added for further mixing, mixed pulp is obtained, the mixed pulp is diluted and then subjected to online papermaking forming treatment, and formed paper sheets are obtained; and step 3, drying the formed paper sheet to obtain the medical dialyzing paper. The medical dialyzing paper with high tensile strength, excellent air permeability, long-acting antibacterial activity and reasonable pore size distribution can be prepared by optimizing and blending the natural plant fibers, the regenerated fibers, the papermaking additive and process parameters in the preparation process, is remarkably superior to commercially available products in the traditional process, and has practical application value.

Description

Technical Field

[0001] The present invention relates to the technical field of papermaking, and in particular to a method for preparing medical dialysis paper. Background Art

[0002] Medical dialysis paper is used as a hard blister sealing cover material for blister packaging of some Class III medical devices. It is usually used in combination with plastic packaging materials such as PETG, PVC or PE, PET film, etc. After being sealed by a sterile packaging heat sealer, it has good sealing properties and together they form a sterile barrier system (SBS).

[0003] Medical dialysis paper needs to have excellent air permeability and antibacterial properties, as well as high tensile strength. Air permeability must allow for gas exchange and can be sterilized using sterilizing steam, such as EO ethylene oxide sterilization or STEAM high-temperature steam sterilization, to ensure the sterility and safety of medical devices or packaging. Antibacterial properties must prevent the penetration of bacteria from the external environment, avoiding the risk of bacterial infection during or after the sterilization of medical devices. Currently, medical dialysis paper on the market has poor air permeability and antibacterial properties, leaving much room for improvement. Low air permeability can affect sterilization effectiveness, while poor antibacterial properties can increase the risk of bacterial penetration, affecting the service life of medical dialysis paper and posing significant safety risks. Researchers are therefore required to further explore these two aspects of medical dialysis paper performance. Summary of the Invention

[0004] In order to overcome the technical difficulties of maintaining high dialyzability while achieving high antibacterial properties for medical dialysis paper, the present invention aims to provide a method for preparing medical dialysis paper, wherein the obtained medical dialysis paper has good air permeability and excellent antibacterial properties.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: In a first aspect, the present invention provides a method for preparing medical dialysis paper, comprising the following steps: Step 1: beating plant fiber and regenerated fiber separately to obtain plant fiber pulp and regenerated fiber pulp; the plant fiber is selected from at least one of flax pulp, wheat straw pulp, and cotton pulp, and the regenerated fiber is selected from at least one of cellulose ester fiber, viscose fiber, and cuprammonium fiber; Step 2: mixing plant fiber pulp and recycled fiber pulp, adding an antimicrobial agent, a wet strength agent, and a reinforcing agent in sequence and further mixing to obtain a mixed pulp, diluting the mixed pulp and performing a screen-coating forming process to obtain a formed paper sheet; Step 3: Drying the formed paper sheet to obtain medical dialysis paper.

[0006] Preferably, the raw materials of the medical dialysis paper are composed of 70-85 parts of plant fiber, 15-30 parts of regenerated fiber, 0.5-1 part of antibacterial agent, 0.1-1 part of wet strength agent, and 0.1-2 parts of reinforcing agent in parts by weight.

[0007] Preferably, the cellulose ester fiber is selected from at least one of cellulose nitrate, cellulose acetate, cellulose acetate butyrate, cellulose xanthate, methyl cellulose, carboxymethyl cellulose, ethyl cellulose, and cyanoethyl cellulose.

[0008] Preferably, the antibacterial agent is selected from at least one of an animal-based antibacterial agent, a plant-based antibacterial agent, and a microbial-based antibacterial agent.

[0009] Further preferably, the animal antibacterial agent is chitosan and its derivatives; the plant antibacterial agent is curcumin; and the microbial antibacterial agent is erythromycin.

[0010] Preferably, the wet strength agent is selected from at least one of urea-formaldehyde resin, melamine-formaldehyde resin and polyethyleneimine resin.

[0011] Preferably, the reinforcing agent is selected from at least one of oxidized starch, acrylate and polyvinyl alcohol, wherein the molecular weight of the polyvinyl alcohol is preferably 60,000-80,000.

[0012] Preferably, in step 1, the beating degree of the plant fiber is 22-25°SR, and the wet weight is 15-20 g; and / or the beating degree of the regenerated fiber is 40-50°SR, and the wet weight is 10-15 g.

[0013] Preferably, in step 2, the solid content of the mixed slurry after dilution is controlled at 0.5-1.5%.

[0014] Preferably, in step 3, the drying temperature is 100-110°C.

[0015] In a second aspect, the present invention provides medical dialysis paper obtained by the preparation method described in the first aspect.

[0016] Preferably, the medical dialysis paper has at least the following performance indicators: a quantitative value of 60±2.0g / m 2 , tensile index is 9.0-11.5Nm / g, air permeability is 10.0-15.0μm.(Pa.s) -1 .

[0017] Compared with the prior art, the technical effects of the present invention are: By optimizing the blending of natural plant fibers, regenerated fibers, papermaking aids, and process parameters of the preparation process, the present invention can produce medical dialysis paper with high tensile strength, excellent air permeability, long-lasting antibacterial properties, and a reasonable pore size distribution. This paper is significantly superior to traditional processes and commercially available products and has practical application value. DETAILED DESCRIPTION

[0018] In the description of the present invention, it should be noted that if specific conditions are not specified in the examples, the experiments were carried out according to conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not specified, are all conventional products that can be purchased commercially.

[0019] A specific embodiment of the present invention provides a method for preparing medical dialysis paper, comprising the following steps: Step 1: beating the plant fiber and the regenerated fiber to obtain plant fiber pulp and regenerated fiber pulp respectively; the plant fiber is selected from at least one of flax pulp, wheat straw pulp, and cotton pulp, and the regenerated fiber is selected from at least one of cellulose ester fiber, viscose fiber, and cuprammonium fiber; The cellulose ester fiber is selected from at least one of the following: cellulose nitrate, cellulose acetate, cellulose acetate butyrate, cellulose xanthate, methyl cellulose, carboxymethyl cellulose, ethyl cellulose, and cyanoethyl cellulose.

[0020] Step 2: mixing plant fiber pulp and recycled fiber pulp, adding an antimicrobial agent, a wet strength agent, and a reinforcing agent in sequence and further mixing to obtain a mixed pulp, diluting the mixed pulp and performing a web-based sheet forming process to obtain a formed paper sheet; the antimicrobial agent is selected from at least one of an animal-based antimicrobial agent, a plant-based antimicrobial agent, and a microbial-based antimicrobial agent; The wet strength agent is selected from at least one of urea-formaldehyde resin, melamine-formaldehyde resin and polyethyleneimine resin.

[0021] The reinforcing agent is selected from at least one of oxidized starch, acrylate and polyvinyl alcohol, and the molecular weight of the polyvinyl alcohol is preferably 60,000-80,000.

[0022] The animal antibacterial agent is preferably chitosan and its derivatives; the plant antibacterial agent is preferably curcumin; and the microbial antibacterial agent is preferably erythromycin.

[0023] Step 3: Drying the formed paper sheet to obtain medical dialysis paper.

[0024] The present invention rationally combines natural plant fibers, regenerated fibers, antimicrobial agents, wet strength agents and reinforcing agents, so that the dialysis paper has excellent antimicrobial properties while ensuring good air permeability and tensile properties.

[0025] In addition, in a specific embodiment of the present invention, the papermaking process on the screen is a wet papermaking process using a rotary screen paper machine. The pulp is dehydrated on the paper machine by using a screen plate and adsorption force to form a paper film; it is then further dehydrated to a moisture content of about 40-50% through a three-stage pressing method, and finally enters a drying cylinder for drying to obtain medical dialysis paper with a moisture content of less than 5%. The drying cylinder drying temperature is 90-120°C.

[0026] The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. However, the following examples are limited to a portion of the research of the present invention and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on this, other embodiments obtained by ordinary technicians in this field without making creative work are all within the scope of protection of the present invention. Example

[0027] This embodiment provides a method for preparing medical dialysis paper, comprising the following steps: 75 parts of flax pulp are processed to a beating degree of 23°SR and a wet weight of 17 g; 25 parts of methyl cellulose ester are processed to a beating degree of 45°SR and a wet weight of 10 g; the natural plant fiber and the regenerated fiber are mixed evenly, 0.5 parts of the antibacterial agent chitosan are added first, then 0.5 parts of the wet strength agent urea-formaldehyde resin are added, and finally 1 part of the reinforcing agent oxidized starch is added. After the pulp is evenly mixed, it is diluted with water to a concentration of 0.8%, and is dehydrated, pressed and dried through wet papermaking to obtain medical dialysis paper. Example

[0028] This embodiment provides a method for preparing medical dialysis paper, comprising the following steps: 80 parts of flax pulp are processed to a beating degree of 22°SR and a wet weight of 15g; 20 parts of methyl cellulose ester are processed to a beating degree of 40°SR and a wet weight of 10g; the natural plant fiber and the regenerated fiber are mixed evenly, 0.6 parts of antibacterial agent chitosan are added first, then 0.5 parts of wet strength agent are added, and finally 1 part of reinforcing agent is added. After the pulp is evenly mixed, it is diluted with water to a concentration of 0.6%, and then dehydrated, pressed and dried through wet papermaking to obtain medical dialysis paper. Example

[0029] This embodiment provides a method for preparing medical dialysis paper, comprising the following steps: 70 parts of flax pulp are processed to a beating degree of 25°SR and a wet weight of 15g; 30 parts of methyl cellulose ester are processed to a beating degree of 40°SR and a wet weight of 10g; the natural plant fiber and the regenerated fiber are mixed evenly, 0.7 parts of antibacterial agent chitosan are added first, then 0.6 parts of wet strength agent are added, and finally 1.5 parts of reinforcing agent are added. After the pulp is evenly mixed, it is diluted with water to a concentration of 0.5%, and then dehydrated, pressed and dried by wet papermaking to obtain medical dialysis paper. Example

[0030] This embodiment provides a method for preparing medical dialysis paper, which differs from Example 1 in that 75 parts of the natural plant fiber are wheat straw pulp. Example

[0031] This embodiment provides a method for preparing medical dialysis paper, which differs from Example 1 in that 75 parts of natural plant fibers are compounded by mixing flax pulp and wheat straw pulp in a ratio of 1:1. Example

[0032] This embodiment provides a method for preparing medical dialysis paper, which differs from Example 1 in that 75 parts of natural plant fibers are compounded by mixing flax pulp and wheat straw pulp in a ratio of 3:1. Example

[0033] This embodiment provides a method for preparing medical dialysis paper, which differs from Example 1 in that the regenerated fiber is viscose fiber. Example

[0034] This embodiment provides a method for preparing medical dialysis paper, which differs from Example 1 in that the regenerated fiber is cuprammonium fiber. Example

[0035] This embodiment provides a method for preparing medical dialysis paper, which differs from Example 1 in that: 75 parts of natural plant fibers are compounded by flax pulp and wheat straw pulp in a ratio of 3:1, and the regenerated fiber is viscose fiber. Example

[0036] This embodiment provides a method for preparing medical dialysis paper, which differs from Example 1 in that the antibacterial agent is curcumin. Example

[0037] This embodiment provides a method for preparing medical dialysis paper, which differs from Example 1 in that the antibacterial agent comprises 0.5 parts of chitosan and 0.5 parts of curcumin. Example

[0038] This embodiment provides a method for preparing medical dialysis paper, which differs from Example 1 in that the wet strength agent is melamine formaldehyde resin. Example

[0039] This embodiment provides a method for preparing medical dialysis paper, which differs from Example 1 in that the wet strength agent is polyethyleneimine resin. Example

[0040] This embodiment provides a method for preparing medical dialysis paper, which differs from Example 1 in that the reinforcing agent is acrylate. Example

[0041] This embodiment provides a method for preparing medical dialysis paper, which differs from Example 1 in that the enhancer is polyvinyl alcohol with a molecular weight of 60,000-80,000. Example

[0042] This embodiment provides a method for preparing medical dialysis paper, which differs from Example 1 in that: 75 parts of natural plant fiber are prepared by compounding flax pulp and wheat straw pulp in a ratio of 3:1, the regenerated fiber is viscose fiber, the antibacterial agent is 0.5 parts of chitosan and 0.5 parts of curcumin, the wet strength agent is polyethyleneimine resin, and the reinforcing agent is acrylate.

[0043] This comparative example provides a method for preparing medical dialysis paper, comprising the following steps: 70 parts of coniferous pulp are processed to a beating degree of 25°SR and a wet weight of 8g; 30 parts of broadleaf pulp are processed to 32°SR and a wet weight of 3g; the coniferous pulp and broadleaf pulp are evenly mixed, and 0.5 parts of a wet strength agent polyamide epichlorohydrin resin are added. After the pulp is evenly mixed, it is diluted with water to a concentration of 0.5%, and is dehydrated and pressed on the screen through wet papermaking. After drying to half dryness, AKD is used for surface sizing, and antibacterial and highly breathable medical dialysis paper is obtained after drying.

[0044] This comparative example provides a method for preparing medical dialysis paper, comprising the following steps: 75 parts of coniferous pulp were processed to a beating degree of 18°SR and a wet weight of 9g; 25 parts of broadleaf pulp were processed to 45°SR and a wet weight of 2g; the coniferous pulp and broadleaf pulp were evenly mixed, and 0.6 parts of a wet strength agent, polyamide epichlorohydrin resin, were added. After the pulp was evenly mixed, it was diluted with water to a concentration of 0.8%, and dehydrated and pressed on the screen through wet papermaking. After drying to half dryness, AKD was used for surface sizing, and antibacterial and highly breathable medical dialysis paper was obtained after drying.

[0045] This comparative example provides a method for preparing medical dialysis paper, comprising the following steps: 75 parts of flax pulp were processed to a beating degree of 22°SR and a wet weight of 9 g; 25 parts of broadleaf pulp were processed to 45°SR and a wet weight of 2 g; coniferous pulp and broadleaf pulp were evenly mixed, and 0.6 parts of a wet strength agent, polyamide epichlorohydrin resin, were added. After the pulp was evenly mixed, it was diluted with water to a concentration of 0.8%, and dehydrated and pressed on the screen through wet papermaking. After drying to half dryness, AKD was used for surface sizing, and antibacterial and highly breathable medical dialysis paper was obtained after drying.

[0046] This comparative example provides a method for preparing medical dialysis paper, comprising the following steps: 75 parts of wheat straw pulp were processed to a beating degree of 22°SR and a wet weight of 9g; 25 parts of broadleaf wood pulp were processed to 45°SR and a wet weight of 2g; coniferous pulp and broadleaf pulp were evenly mixed, and 0.6 parts of wet strength agent polyamide epichlorohydrin resin were added. After the pulp was evenly mixed, it was diluted with water to a concentration of 0.8%, and dehydrated and pressed on the screen through wet papermaking. After drying to half dryness, AKD was used for surface sizing, and antibacterial and highly breathable medical dialysis paper was obtained after drying.

[0047] This comparative example provides a method for preparing medical dialysis paper, comprising the following steps: 75 parts of methyl cellulose ester regenerated fiber were processed to a beating degree of 44°SR and a wet weight of 9g; 25 parts of broadleaf pulp were processed to 45°SR and a wet weight of 2g; coniferous pulp and broadleaf pulp were evenly mixed, and 0.6 parts of wet strength agent were added. After the pulp was evenly mixed, it was diluted with water to a concentration of 0.8%, and dehydrated and pressed on the screen through wet papermaking. After drying to half dryness, AKD was used for surface sizing, and antibacterial and highly breathable medical dialysis paper was obtained after drying.

[0048] Test Trial Performance analysis and testing of the medical dialysis papers prepared in Examples 1-16 and Comparative Examples 1-5: Pore ​​size analysis: Use PMI pore size analyzer to test the pore size of paper samples.

[0049] Antibacterial properties: Test subjects were medical dialysis paper samples stored for one and six months. Under sterile conditions, Staphylococcus aureus was inoculated onto the culture medium using a triangular spatula. The culture medium was divided into four equal portions, each containing four antibacterial paper discs. The culture medium was then placed in an incubator controlled at 37°C and 72% humidity for 24 hours. The results were observed, and the diameters of the inhibition zones were measured and averaged.

[0050] Tensile index: The test method adopts GB / T 453-2002.

[0051] The test results are shown in Table 1. Note: -- indicates non-bacteriostatic; commercially available medical dialysis paper comes from Zhejiang Hengda New Materials Co., Ltd.

[0052] As can be seen from the table, the combination of flax pulp and wheat straw pulp (such as Examples 9 and 16) significantly improves tensile strength and air permeability compared to other examples. Among regenerated fibers, viscose fiber is more conducive to balancing tensile strength and air permeability than cuprammonia fiber. The role of additives should not be underestimated. The dialysis paper of the present invention, by introducing a natural antimicrobial agent, exhibits significant inhibitory effects against Staphylococcus aureus, while comparative Examples 1-5, which do not incorporate an antimicrobial agent, have no inhibitory effect against Staphylococcus aureus. Furthermore, chitosan and chitosan + curcumin combinations exhibit stable, long-lasting antibacterial properties. Using polyethyleneimine resin as a wet strength agent demonstrates superior tensile strength and air permeability compared to urea-formaldehyde or melamine-formaldehyde resins. Reinforcing agents such as acrylates and oxidized starch significantly improve tensile strength, while polyvinyl alcohol with a molecular weight of 60,000-80,000 significantly improves air permeability. In addition, the air permeability of the embodiments of the present invention is 7-9 times that of commercially available products, the tensile index is significantly improved compared to commercially available products, and it has long-lasting antibacterial properties, and its comprehensive performance is comprehensively leading.

[0053] In summary, the present invention optimizes the natural fiber ratio, selects viscose fiber as the regenerated fiber, adds antibacterial agents, and adopts appropriate wet strength agents and reinforcing agents to prepare medical dialysis paper with high tensile strength, excellent air permeability, long-term antibacterial properties and a reasonable pore size distribution. It is significantly superior to traditional processes and commercially available products and has practical application value.

[0054] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for preparing medical dialysis paper, characterized in that, The steps include: Step 1: beating plant fiber and regenerated fiber separately to obtain plant fiber pulp and regenerated fiber pulp; the plant fiber is selected from at least one of flax pulp, wheat straw pulp, and cotton pulp, and the regenerated fiber is selected from at least one of cellulose ester fiber, viscose fiber, and cuprammonium fiber; Step 2: mixing plant fiber pulp and recycled fiber pulp, adding an antimicrobial agent, a wet strength agent, and a reinforcing agent in sequence and further mixing to obtain a mixed pulp, diluting the mixed pulp and performing a screen-coating forming process to obtain a formed paper sheet; Step 3: Drying the formed paper sheet to obtain medical dialysis paper.

2. The preparation method according to claim 1, characterized in that The raw materials of the medical dialysis paper are composed of 70-85 parts of plant fiber, 15-30 parts of regenerated fiber, 0.5-1 part of antibacterial agent, 0.1-1 part of wet strength agent, and 0.1-2 parts of reinforcing agent in parts by weight.

3. The preparation method according to claim 1 or 2, characterized in that The antibacterial agent is selected from at least one of an animal antibacterial agent, a plant antibacterial agent and a microbial antibacterial agent.

4. The preparation method according to claim 1 or 2, characterized in that The wet strength agent is selected from at least one of urea-formaldehyde resin, melamine-formaldehyde resin and polyethyleneimine resin.

5. The preparation method according to claim 1 or 2, characterized in that The reinforcing agent is selected from at least one of oxidized starch, acrylate and polyvinyl alcohol, wherein the molecular weight of the polyvinyl alcohol is preferably 60,000-80,000.

6. The preparation method according to claim 1, characterized in that In the step 1, the beating degree of the plant fiber is 22-25°SR, and the wet weight is 15-20 g; and / or the beating degree of the regenerated fiber is 40-50°SR, and the wet weight is 10-15 g.

7. The preparation method according to claim 1, characterized in that In step 2, the solid content of the mixed slurry after dilution is controlled at 0.5-1.5%.

8. The preparation method according to claim 1, characterized in that In step 3, the drying temperature is 100-110°C.

9. The medical dialysis paper obtained by the preparation method according to any one of claims 1 to 8.

10. The medical dialysis paper according to claim 9, characterized in that The medical dialysis paper has at least the following performance indicators: a quantitative value of 60±2.0g / m 2 , tensile index is 9.0-11.5Nm / g, air permeability is 10.0-15.0μm.(Pa.s) -1 .

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