A process for the impregnation of medical packaging base paper

Abstract

The present application relates to the technical field of medical packaging materials, and particularly relates to a kind of medical packaging base paper impregnation strengthening process, including base paper preparation: selecting the base paper with basis weight of 55g / m 2 -85g / m 2 , initial air permeability >1000ml / min;Impregnation liquid preparation: the aqueous polymer latex is prepared into impregnation liquid with concentration of 10%-20%, and is uniformly stirred;Impregnation treatment, drying and balancing process route, to complete the impregnation strengthening treatment of base paper.Through the construction of base paper basic parameters, impregnation liquid system concentration and impregnation drying process parameters, the base paper after impregnation under this process realizes the performance balance of high air permeability, high strength, easy heat sealing, clean peeling.

Description

Technical Field

[0001] This invention relates to the field of medical packaging materials technology, specifically to an impregnation and reinforcement process for medical packaging base paper. Background Technology

[0002] Driven by global environmental protection and sustainable development concepts, and against the backdrop of increasing demands for device safety in the medical industry, bio-based medical packaging paper has become a core material for sterilization packaging of medical devices due to its advantages in biodegradability, resource sustainability, and environmental compatibility. Among these, medical dialysis paper, as a key substrate for sterilization packaging, must meet basic indicators such as air permeability, water absorption, and tensile strength, and also possess five core properties: microbial barrier, heat sealing, tear resistance, sterilization adaptability, and clean peelability, to ensure the sterility and safety of medical devices throughout the entire process from packaging to use.

[0003] However, existing medical dialysis papers suffer from significant technical bottlenecks. They have poor heat-sealing properties and easily generate paper dust during peeling, posing a risk of contamination to sterile medical devices. To improve the heat-sealing properties and mechanical strength of the paper, an impregnation process is often used in industry. This process allows latex to penetrate between the fibers of the base paper, forming a reinforcing network, strengthening the paper base, and optimizing the heat-sealing foundation. However, this process significantly reduces the paper's air permeability, affecting the penetration of sterilization media. This leads to an irreconcilable contradiction between air permeability and mechanical strength. The decrease in air permeability is related to factors such as impregnation depth, latex density, and impregnation amount. The deeper the densification structure and the more severe the pore blockage, the worse the air permeability. In addition, while the use of certain reinforcing agents (such as cationic polyacrylamide) can improve tensile strength, it leads to a decrease in the tear strength of the paper. When using polyamide epoxy resin or softeners for impregnation, the problem of decreased tear strength remains unresolved. Furthermore, multi-component impregnation systems are prone to flocculation and sedimentation due to charge differences, resulting in poor stability and making it difficult to achieve synergistic performance improvement.

[0004] Existing technologies, such as Chinese invention patent CN117328288A, disclose a medical dialysis paper and its manufacturing process. This process uses a mixed pulp of wood pulp, hardwood pulp, and modified viscose fiber as raw materials for papermaking. While ensuring paper strength, it effectively improves the smoothness, opacity, and printability of the dialysis paper. However, it does not solve the fundamental problem of the imbalance between air permeability and mechanical properties caused by the impregnation process itself. Therefore, there is an urgent need to develop an impregnation enhancement process that can simultaneously optimize mechanical strength, heat-sealing properties, and clean peelability while maintaining high air permeability. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide an impregnation and reinforcement process for medical packaging base paper. By constructing basic parameters for the base paper, an impregnation solution system, and impregnation and drying process parameters, the impregnated base paper achieves a balance of high air permeability, high strength, easy heat sealing, and clean peeling performance under this process.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: An impregnation and reinforcement process for medical packaging base paper includes the following steps: Step 1, Preparation of base paper: Select paper with a basis weight of 55 g / m³ 2 -85g / m 2 The base paper has an initial air permeability >1000ml / min; Step 2, Impregnation solution preparation: Add water-based polymer latex to a solvent to prepare an impregnation solution with a concentration of 10%-20%, and stir evenly; Step 3, Impregnation treatment: Immerse the base paper from Step 1 into the latex impregnation solution prepared in Step 2; Step 4, Drying and Balancing: Dry the impregnated paper, remove it and let it stand to balance, thus completing the impregnation enhancement treatment.

[0007] Preferably, the transverse tensile index of the base paper in step 1 is >15.6 N·m·g. -1 Transverse wet tensile index > 5.2 N·m·g -1 Longitudinal tensile index >36 N·m·g -1 Longitudinal wet tensile index >10.4 N·m·g -1 Transverse tear index > 5.5 mN·m 2 ·g -1 Longitudinal tear index >4.7 mN·m 2 ·g -1 Lateral stiffness > 30.0 mN·m, longitudinal stiffness > 29.2 mN·m, and lateral zero-pitch tensile strength > 36.2 N·cm. -1 Longitudinal zero-pitch tensile strength > 60.0 N·cm -1 .

[0008] Preferably, the solvent is deionized water, and the latex is one or a combination of styrene-acrylic emulsion, styrene-butadiene latex, and styrene-acrylic latex.

[0009] Preferably, in step 2, a magnetic stirrer is used for stirring, and the stirring speed is 400-500 r / min.

[0010] Preferably, the conditions for the impregnation treatment are: after stirring, let it stand for 5 minutes, and if there is no stratification, it can be used for impregnation.

[0011] Preferably, the impregnation method in step 3 is single-sided impregnation or double-sided impregnation. Single-sided impregnation is impregnating the reverse side of the original paper, and double-sided impregnation is impregnating both sides of the original paper at the same time.

[0012] Preferably, in step 3, the temperature of the impregnation solution is 25-30°C, and the impregnation time is 2-5 seconds.

[0013] Preferably, in step 4, the drying is performed using an electric thermostatic drying oven, with a drying temperature of 105℃-135℃ and a drying time of 5-20 minutes.

[0014] Preferably, in step 4, the balancing process involves balancing the moisture in a dryer for 24 hours.

[0015] The medical packaging paper prepared by the process provided by this invention can be used for sterilization packaging of medical devices, clean packaging for food processing, clean protective packaging for electronics, and special packaging for environmental protection and emergency use.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. Achieving high air permeability and high strength: This invention precisely limits the basic strength of the base paper, latex concentration, impregnation time, and drying parameters. While the latex appropriately penetrates the fibers to form a protective layer to improve mechanical properties, it minimizes the blockage of the paper's internal pores, maintains high air permeability, significantly improves the paper's tensile strength, bursting strength, and stiffness, avoids paper damage during processing, transportation, and use, strengthens the stability of the sterile barrier, and solves the core problem of the inability to achieve both air permeability and strength in existing impregnation processes, meeting the stringent air permeability requirements of sterilization processes.

[0017] 2. Optimized heat-sealing and clean peelability to eliminate the risk of sterile contamination: Traditional medical dialysis paper commonly suffers from poor heat sealing and lint shedding during peeling. This process forms a uniform and dense protective layer on the paper surface through latex impregnation. On one hand, it improves the paper's heat-sealing foundation, enhancing heat-sealing strength and sealing performance, preventing the sterile barrier from being compromised due to heat-sealing failure during sterilization or transportation. On the other hand, it strengthens the bonding force between fibers, effectively reducing paper lint shedding during peeling, eliminating the risk of peel contamination at the source, and ensuring the sterile safety of medical devices from packaging to use, meeting the core performance requirements of "microbial barrier + clean peel" for medical packaging.

[0018] 3. The process is simple and controllable, suitable for industrial production, and has significant cost advantages: This invention clearly defines the types of raw materials, concentration ranges, and stirring process parameters for multi-component latex. The stirring speed of 400-500 r / min and the 5-minute settling time do not require stratification, effectively avoiding the flocculation and sedimentation problems caused by charge differences in multi-component latex, thus significantly improving the stability of the impregnation system. At the same time, the core advantage of the process route constructed by this invention lies in the synergistic optimization of three aspects: the quantitative definition of key parameters such as impregnation solution concentration, impregnation time, and drying temperature avoids batch-to-batch fluctuations and improves the uniformity of mass production quality; the use of domestically produced large-scale latex reduces import dependence, controls costs, and ensures supply chain stability. It does not require complex compounding or special equipment, has low cost, and is suitable for large-scale applications. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to specific embodiments. These embodiments are for illustrative purposes only and do not constitute any limitation on the scope of protection of the present invention.

[0020] The impregnation and reinforcement process for medical packaging base paper provided by this invention includes the following steps: Step 1, Preparation of base paper: Select paper with a thickness of 0.099-0.154mm and a basis weight of 55g / m³. 2 -85g / m 2 Initial air permeability >1000ml / min, transverse tensile index >15.6N·m·g -1 Transverse wet tensile index > 5.2 N·m·g -1 Longitudinal tensile index >36 N·m·g -1 Longitudinal wet tensile index >10.4 N·m·g -1 Transverse tear index > 5.5 mN·m 2 ·g -1 Longitudinal tear index >4.7 mN·m 2 ·g -1 Lateral stiffness >30.0 mN·m, longitudinal stiffness >29.2 mN·m, and lateral zero-pitch tensile strength >36.2 N·cm. -1 Longitudinal zero-pitch tensile strength > 60.0 N·cm -1 The base paper; In this embodiment of the invention, the initial air permeability of the base paper is preferably 2400-3950 ml / min; Step 2, Impregnation solution preparation: Add one or more of the following to deionized water to prepare an impregnation solution with a concentration of 10%-20% and use a magnetic stirrer to stir evenly at a speed of 400r / min-500r / min. After stirring, let it stand for 5 minutes. If there is no stratification, it can be used for impregnation. This effectively avoids the problem of flocculation and sedimentation caused by the charge difference of multi-component latexes, and significantly improves the stability of the impregnation system. Step 3, Impregnation treatment: Immerse the base paper from Step 1 into the latex impregnation solution prepared in Step 2 for 2-5 seconds, at a temperature of 25°C-35°C. The impregnation method can be single-sided or double-sided. In this embodiment of the invention, single-sided impregnation is preferred. Single-sided impregnation involves impregnating the reverse side of the base paper (the side to be coated with adhesive), which aims to enhance heat-sealing performance while avoiding air permeability loss caused by impregnating the front side (printing side). Double-sided impregnation involves impregnating both sides simultaneously, which is suitable for materials with high requirements for overall mechanical strength and uniformity on both sides. Step 4, Drying and Balancing: Place the impregnated paper into an electric constant temperature drying oven and dry it at a temperature of 105℃-135℃ for 5min-20min. After drying, transfer it to a desiccator to balance the moisture content. The balancing time is 24 hours to complete the impregnation enhancement treatment.

[0021] This invention uses an electric thermostatic forced-air drying oven, model DHG-9053A, which can precisely control temperature fluctuations within ±1℃, ensuring the stability of the drying process.

[0022] The following description, in conjunction with specific embodiments, provides further details.

[0023] Example 1 Step 1, Preparation of base paper: Select paper with a basis weight of 67 g / m 2 The base paper, with a thickness of 0.121mm and an initial air permeability of 2950ml / min, is cut into 15×15cm sizes and set aside. Step 2, Preparation of impregnation solution: Add styrene-acrylic emulsion to deionized water to prepare a latex impregnation solution with a concentration of 15%, and stir evenly; Step 3, Impregnation treatment: Using a single-sided impregnation method, the base paper from Step 1 is immersed in the latex impregnation solution prepared in Step 2 for 3 seconds, and the temperature of the impregnation solution is 25°C. Step 4, Drying and Balancing: Place the impregnated paper into an electric constant temperature drying oven and dry it at 105℃ for 20 minutes. After drying, transfer it to a desiccator to equilibrate for 24 hours to complete the impregnation enhancement treatment.

[0024] After the impregnation and drying processes in this embodiment, the impregnation amount is 15g / m². 2 The thickness is 0.123mm; Paper performance indicators were measured: the air permeability of the finished paper was 1141 ml / min, the air permeability reduction rate was 61.32%, and the transverse tensile index was 50.76 N·m·g. -1 Transverse wet tensile index: 34.58 N·m·g -1 Longitudinal tensile index: 93.93 N·m·g -1 The longitudinal wet tensile index is 45.02 N·m·g. -1 The transverse tear index was 7.91 mN·m. 2 ·g -1 The longitudinal tear index was 10.24 mN·m. 2 ·g -1 The transverse stiffness is 38.44 mN·m, the longitudinal stiffness is 37.46 mN·m, and the transverse zero-pitch tensile strength is 94.20 N·cm. -1 The longitudinal zero-pitch tensile strength is 100.47 N·cm. -1The contact angle of the dipped side is 95.46°, and the contact angle of the reverse side is 86.90°.

[0025] Example 2 Step 1, Preparation of base paper: Select paper with a basis weight of 67 g / m 2 The base paper, with a thickness of 0.121mm and an initial air permeability of 2938ml / min, is cut into 15×15cm sizes and set aside. Step 2, preparation of impregnation solution: Styrene-acrylic emulsion and styrene-butadiene latex are compounded in a mass ratio of 1:0.1, and then deionized water is added to dilute it into a latex impregnation solution with a concentration of 20%, and the mixture is stirred evenly; Step 3, Impregnation treatment: Using a single-sided impregnation method, the base paper from Step 1 is immersed in the latex impregnation solution prepared in Step 2 for 2 seconds, and the temperature of the impregnation solution is 25°C. Step 4, Drying and Balancing: Place the impregnated paper into an electric constant temperature drying oven and dry it at 115℃ for 15 minutes. After drying, transfer it to a desiccator to equilibrate for 24 hours to complete the impregnation enhancement treatment.

[0026] After the impregnation and drying processes in this embodiment, the impregnation amount is 15g / m². 2 The thickness is 0.123mm; Paper performance indicators were measured: the air permeability of the finished paper was 1114 ml / min, the air permeability reduction rate was 62.08%, and the transverse tensile index was 50.87 N·m·g. -1 Transverse wet tensile index: 34.53 N·m·g -1 Longitudinal tensile index: 95.02 N·m·g -1 The longitudinal wet tensile index is 45.77 N·m·g. -1 The transverse tear index is 7.85 mN·m. 2 ·g -1 The longitudinal tear index was 10.03 mN·m. 2 ·g -1 The transverse stiffness is 38.51 mN·m, the longitudinal stiffness is 37.53 mN·m, and the transverse zero-pitch tensile strength is 95.48 N·cm. -1 The longitudinal zero-pitch tensile strength is 100.65 N·cm. -1 The contact angle of the dipped side is 96.18°, and the contact angle of the reverse side is 87.52°.

[0027] Example 3 Step 1, Preparation of base paper: Select paper with a basis weight of 67 g / m 2 The base paper, with a thickness of 0.121mm and an initial air permeability of 2950ml / min, is cut into 15×15cm sizes and set aside. Step 2, preparation of impregnation solution: Styrene-acrylic emulsion, styrene-butadiene latex and styrene-acrylic emulsion are mixed in a mass ratio of 1:1:0.1, and then deionized water is added to dilute it into a latex impregnation solution with a concentration of 10% and stirred evenly; Step 3, Impregnation treatment: Using a single-sided impregnation method, the base paper from Step 1 is immersed in the latex impregnation solution prepared in Step 2 for 5 seconds, and the temperature of the impregnation solution is 35°C. Step 4, Drying and Balancing: Place the impregnated paper into an electric constant temperature drying oven and dry it at 125℃ for 10 minutes. After drying, transfer it to a desiccator to equilibrate for 24 hours to complete the impregnation enhancement treatment.

[0028] After the impregnation and drying processes in this embodiment, the impregnation amount is 15g / m². 2 The thickness is 0.123mm; Paper performance indicators were measured: the air permeability of the finished paper was 1141 ml / min, the air permeability reduction rate was 61.32%, and the transverse tensile index was 50.82 N·m·g. -1 Transverse wet tensile index: 34.55 N·m·g -1 Longitudinal tensile index: 94.55 N·m·g -1 The longitudinal wet tensile index is 45.45 N·m·g. -1 The transverse tear index was 7.87 mN·m. 2 ·g -1 The longitudinal tear index was 10.12 mN·m. 2 ·g -1 The transverse stiffness is 38.48 mN·m, the longitudinal stiffness is 37.50 mN·m, and the transverse zero-pitch tensile strength is 94.93 N·cm. -1 The longitudinal zero-pitch tensile strength is 100.57 N·cm. -1 The contact angle of the dipped side is 95.89°, and the contact angle of the reverse side is 87.25°.

[0029] Example 4 Step 1, Preparation of base paper: Select paper with a basis weight of 67 g / m 2 The base paper, with a thickness of 0.121mm and an initial air permeability of 2950ml / min, is cut into 15×15cm sizes and set aside. Step 2, preparation of impregnation solution: Styrene-acrylic emulsion, styrene-butadiene latex and styrene-acrylic emulsion are mixed in a mass ratio of 1:1:0.1, and then deionized water is added to dilute it into a latex impregnation solution with a concentration of 15% and stirred evenly; Step 3, Impregnation treatment: Using a single-sided impregnation method, the base paper from Step 1 is immersed in the latex impregnation solution prepared in Step 2 for 2 seconds, and the temperature of the impregnation solution is 30°C. Step 4, Drying and Balancing: Place the impregnated paper into an electric constant temperature drying oven and dry it at 135℃ for 5 minutes. After drying, transfer it to a desiccator to equilibrate for 24 hours to complete the impregnation enhancement treatment.

[0030] After the impregnation and drying processes in this embodiment, the impregnation amount is 15g / m². 2 The thickness is 0.123mm. Paper performance indicators were measured: the air permeability of the finished paper was 1104 ml / min, the air permeability reduction rate was 62.58%, and the transverse tensile index was 50.91 N·m·g. -1 Transverse wet tensile index: 34.51 N·m·g -1 Longitudinal tensile index: 95.41 N·m·g -1 The longitudinal wet tensile index is 46.03 N·m·g. -1 The transverse tear index was 7.83 mN·m. 2 ·g -1 The longitudinal tear index was 9.95 mN·m. 2 ·g -1 The transverse stiffness is 38.53 mN·m, the longitudinal stiffness is 37.55 mN·m, and the transverse zero-pitch tensile strength is 95.93 N·cm. -1 The longitudinal zero-pitch tensile strength is 100.71 N·cm. -1 The contact angle of the dipped side is 96.43°, and the contact angle of the reverse side is 87.74°.

[0031] Example 5 Step 1, Preparation of base paper: Select paper with a basis weight of 55 g / m 2 The base paper, with a thickness of 0.099mm and an initial air permeability of 3950ml / min, is cut into 15×15cm sizes and set aside. Step 2, preparation of impregnation solution: Styrene-acrylic emulsion, styrene-butadiene latex and styrene-acrylic emulsion are mixed in a mass ratio of 1:1:0.1, and then deionized water is added to dilute it into a latex impregnation solution with a concentration of 15% and stirred evenly; Step 3, Impregnation treatment: Using a single-sided impregnation method, the base paper from Step 1 is immersed in the latex impregnation solution prepared in Step 2 for 3 seconds, and the temperature of the impregnation solution is 25°C. Step 4, Drying and Balancing: Place the impregnated paper into an electric constant temperature drying oven and dry it at 105℃ for 20 minutes. After drying, transfer it to a desiccator to equilibrate for 24 hours to complete the impregnation enhancement treatment.

[0032] After the impregnation and drying processes in this embodiment, the impregnation amount is 15g / m². 2 The thickness is 0.101mm. Paper performance indicators were measured: the air permeability of the finished paper was 2475 ml / min, the air permeability reduction rate was 37.34%, and the transverse tensile index was 37.31 N·m·g. -1 Transverse wet tensile index: 23.28 N·m·g -1 Longitudinal tensile index: 63.72 N·m·g -1 The longitudinal wet tensile index is 37.31 N·m·g. -1 The transverse tear index was 6.46 mN·m. 2 ·g -1 The longitudinal tear index was 8.31 mN·m. 2 ·g -1 The transverse stiffness is 31.59 mN·m, the longitudinal stiffness is 30.78 mN·m, and the transverse zero-pitch tensile strength is 77.93 N·cm. -1 The longitudinal zero-pitch tensile strength is 82.56 N·cm. -1 The contact angle of the dipped side is 78.72°, and the contact angle of the reverse side is 71.62°.

[0033] Example 6 Step 1, Preparation of base paper: Select paper with a basis weight of 85g / m 2 The base paper, with a thickness of 0.154mm and an initial air permeability of 2400ml / min, is cut into 15×15cm sizes and set aside. Step 2, Preparation of impregnation solution: Add styrene-acrylic emulsion to deionized water to prepare a latex impregnation solution with a concentration of 15%, and stir evenly; Step 3, Impregnation treatment: Using a single-sided impregnation method, the base paper from Step 1 is immersed in the latex impregnation solution prepared in Step 2 for 3 seconds, and the temperature of the impregnation solution is 25°C. Step 4, Drying and Balancing: Place the impregnated paper into an electric constant temperature drying oven and dry it at 115℃ for 15 minutes. After drying, transfer it to a desiccator to equilibrate for 24 hours to complete the impregnation enhancement treatment.

[0034] After the impregnation and drying processes in this embodiment, the impregnation amount is 15g / m². 2 The thickness is 0.156mm. Paper performance indicators were tested: the air permeability of the finished paper was 898 ml / min, the air permeability reduction rate was 65.58%, and the transverse tensile index was 64.40 N·m·g. -1 Transverse wet tensile index: 43.87 N·m·g -1 Longitudinal tensile index: 119.16 N·m·g -1 The longitudinal wet tensile index is 57.11 N·m·g. -1 The transverse tear index was 10.04 mN·m. 2 ·g -1The longitudinal tear index was 12.99 mN·m. 2 ·g -1 The transverse stiffness is 48.77 mN·m, the longitudinal stiffness is 47.52 mN·m, and the transverse zero-pitch tensile strength is 119.51 N·cm. -1 The longitudinal zero-pitch tensile strength is 127.46 N·cm. -1 The contact angle of the dipped side is 121.11°, and the contact angle of the reverse side is 110.25°.

[0035] Example 7 Step 1, Preparation of base paper: Select paper with a basis weight of 85g / m 2 The base paper, with a thickness of 0.154mm and an initial air permeability of 2400ml / min, is cut into 15×15cm sizes and set aside. Step 2, preparation of impregnation solution: Styrene-acrylic emulsion and styrene-butadiene latex are compounded in a mass ratio of 1:0.1, and then deionized water is added to dilute it into a latex impregnation solution with a concentration of 10%, and the mixture is stirred evenly; Step 3, Impregnation treatment: Using a single-sided impregnation method, the base paper from Step 1 is immersed in the latex impregnation solution prepared in Step 2 for 5 seconds, and the temperature of the impregnation solution is 35°C. Step 4, Drying and Balancing: Place the impregnated paper into an electric constant temperature drying oven and dry it at 125℃ for 10 minutes. After drying, transfer it to a desiccator to equilibrate for 24 hours to complete the impregnation enhancement treatment.

[0036] After the impregnation and drying processes in this embodiment, the impregnation amount is 15g / m². 2 The thickness is 0.156mm. Paper performance indicators were tested: the air permeability of the finished paper was 779 ml / min, the air permeability reduction rate was 67.54%, and the transverse tensile index was 64.54 N·m·g. -1 Transverse wet tensile index: 43.81 N·m·g -1 Longitudinal tensile index: 120.55 N·m·g -1 The longitudinal wet tensile index is 58.07 N·m·g. -1 The transverse tear index was 9.96 mN·m. 2 ·g -1 The longitudinal tear index was 12.72 mN·m. 2 ·g -1 The transverse stiffness is 48.86 mN·m, the longitudinal stiffness is 47.61 mN·m, and the transverse zero-pitch tensile strength is 121.13 N·cm. -1 The longitudinal zero-pitch tensile strength is 127.69 N·cm. -1 The contact angle of the dipped side is 122.02°, and the contact angle of the reverse side is 111.03°.

[0037] Example 8 Step 1, Preparation of base paper: Select paper with a basis weight of 85g / m 2 The base paper, with a thickness of 0.154mm and an initial air permeability of 2400ml / min, is cut into 15×15cm sizes and set aside. Step 2, preparation of impregnation solution: Styrene-acrylic emulsion, styrene-butadiene latex and styrene-acrylic emulsion are mixed in a mass ratio of 1:1:0.1, and then deionized water is added to dilute it into a latex impregnation solution with a concentration of 20% and stirred evenly; Step 3, Impregnation treatment: Using a single-sided impregnation method, the base paper from Step 1 is immersed in the latex impregnation solution prepared in Step 2 for 2 seconds, and the temperature of the impregnation solution is 25°C. Step 4, Drying and Balancing: Place the impregnated paper into an electric constant temperature drying oven and dry it at 135℃ for 5 minutes. After drying, transfer it to a desiccator to equilibrate for 24 hours to complete the impregnation enhancement treatment.

[0038] After the impregnation and drying processes in this embodiment, the impregnation amount is 15g / m². 2 The thickness is 0.156mm.

[0039] Paper performance indicators were tested: the air permeability of the finished paper was 810 ml / min, the air permeability reduction rate was 66.25%, and the transverse tensile index was 64.47 N·m·g. -1 Transverse wet tensile index: 43.83 N·m·g -1 Longitudinal tensile index: 119.95 N·m·g -1 The longitudinal wet tensile index is 57.66 N·m·g. -1 The transverse tear index was 9.98 mN·m. 2 ·g -1 The longitudinal tear index was 12.84 mN·m. 2 ·g -1 The transverse stiffness is 48.82 mN·m, the longitudinal stiffness is 47.57 mN·m, and the transverse zero-pitch tensile strength is 120.43 N·cm. -1 The longitudinal zero-pitch tensile strength is 127.59 N·cm. -1 The contact angle of the dipped side is 121.65°, and the contact angle of the reverse side is 110.69°.

[0040] Performance Comparison Analysis: Examples 1-8 all employed a single-sided impregnation reinforcement process, with a final impregnation amount of 15 g / m². 2 Paper treated with the process of this invention exhibits a controlled decrease in air permeability of approximately 37%-67.53% compared to its initial air permeability. Furthermore, its mechanical properties, such as tensile index, tear index, and stiffness, are significantly improved compared to the baseline values ​​of the original paper. Specifically, the transverse tensile index reaches a maximum of 64.5 N·m·g.-1 This represents an improvement of over four times, with the lateral tear index reaching a maximum of 10.0 mN·m. 2 ·g -1 The paper exhibits an approximately 82% increase in permeability and a maximum transverse stiffness of 48.8 mN·m, representing an approximately 63% increase. This demonstrates that the invention achieves its objective of significantly enhancing the mechanical properties of paper while maintaining an acceptable level of high permeability, effectively resolving a long-standing technical challenge in the field. Furthermore, the increased contact angle on the sizing surface indicates improved hydrophobicity and heat-sealing properties, while the lower contact angle on the reverse side facilitates subsequent processing. This invention achieves a performance balance of "high permeability, high strength, easy heat sealing, and clean peeling," making it widely applicable in scenarios such as sterilization packaging for medical devices, clean packaging for food processing, protective packaging in the electronic cleanroom field, and specialized packaging for environmental protection and emergency applications.

Claims

1. An impregnation and reinforcement process for medical packaging base paper, characterized in that, Includes the following steps: Step 1, Preparation of base paper: Select paper with a basis weight of 55 g / m³ 2 -85g / m 2 The base paper has an initial air permeability >1000ml / min; Step 2, Impregnation solution preparation: Add water-based polymer latex to a solvent to prepare an impregnation solution with a concentration of 10%-20%, and stir evenly; Step 3, Impregnation treatment: Immerse the base paper from Step 1 into the latex impregnation solution prepared in Step 2; Step 4, Drying and Balancing: Dry the impregnated paper, remove it and let it stand to balance, thus completing the impregnation enhancement treatment.

2. The impregnation and reinforcement process for medical packaging base paper according to claim 1, characterized in that, The transverse tensile index of the base paper mentioned in step 1 is >15.6 N·m·g -1 Transverse wet tensile index > 5.2 N·m·g -1 Longitudinal tensile index >36 N·m·g -1 Longitudinal wet tensile index >10.4 N·m·g -1 Transverse tear index > 5.5 mN·m 2 ·g -1 Longitudinal tear index >4.7 mN·m 2 ·g -1 Lateral stiffness > 30.0 mN·m, longitudinal stiffness > 29.2 mN·m, and lateral zero-pitch tensile strength > 36.2 N·cm. -1 Longitudinal zero-pitch tensile strength > 60.0 N·cm -1 .

3. The impregnation and reinforcement process for medical packaging base paper according to claim 1, characterized in that, The solvent is deionized water, and the latex is one or a combination of styrene-acrylic emulsion, styrene-butadiene latex, and styrene-acrylic latex.

4. The impregnation and reinforcement process for medical packaging base paper according to claim 1, characterized in that, In step 2, a magnetic stirrer is used for stirring, and the stirring speed is 400-500 r / min.

5. The impregnation and reinforcement process for medical packaging base paper according to claim 1, characterized in that, The conditions for the impregnation treatment are as follows: after stirring, let it stand for 5 minutes, and if there is no stratification, it can be used for impregnation.

6. The impregnation and reinforcement process for medical packaging base paper according to claim 1, characterized in that, In step 3, the impregnation method is either single-sided impregnation or double-sided impregnation. Single-sided impregnation involves impregnating the reverse side of the original paper, while double-sided impregnation involves impregnating both the front and back sides of the original paper simultaneously.

7. The impregnation and reinforcement process for medical packaging base paper according to claim 1, characterized in that, In step 3, the temperature of the impregnation solution is 25-30℃, and the impregnation time is 2-5 seconds.

8. The impregnation and reinforcement process for medical packaging base paper according to claim 1, characterized in that, In step 4, the drying process uses an electric thermostatic drying oven with a drying temperature of 105℃-135℃ and a drying time of 5-20 minutes.

9. The impregnation and reinforcement process for medical packaging base paper according to claim 1, characterized in that, In step 4, balancing involves balancing the moisture in a dryer for 24 hours.

10. The impregnation and reinforcement process for medical packaging base paper according to any one of claims 1-9, characterized in that, The medical packaging paper prepared using the aforementioned process can be used for sterilization packaging of medical devices, clean packaging for food processing, clean protective packaging for electronics, and special packaging for environmental protection and emergency applications.