Breathability of Medical Dialysis Paper
Returns List Reffer：kmnadmin Click number： Release time：2022-11-18 16:10:00
Compared with medical non woven fabric, medical dialysis paper has the characteristics of low price and convenient use. It can be heat-sealed or glue-sealed with membrane materials such as PE and PP, and is often used as packaging materials for medical devices in the medical packaging industry. At present, the domestic packaging materials are mainly ETO ethylene oxide method and high temperature and humid steam method, so the medical dialysis paper is required to have a certain permeability, and has a small aperture, so as to block bacteria and dust, but allow ethylene oxide gas or steam through.
There are many factors affecting the air permeability of paper, such as raw materials, beater technology (such as beater concentration, beater power, beater degree, etc.), papermaking technology such as pressing pressure, drying method, pressing light, etc. At the same time, the packaging of medical devices also needs to be fully sealed, protect the contents of the package, fix the contents of the package, resist puncture and friction, etc. Therefore, the physical performance indicators such as tensile strength and break resistance of medical dialysis paper should meet the requirements of ISO11607, EN868 series and GB19633 and other standards.
The beating degree and ratio of coniferous wood pulp and broadleaf wood pulp have important influence on the breathability of medical dialysis paper. Medical dialysis paper needs to meet many indicators such as: vertical and vertical tear degree ≥550mN, longitudinal tensile strength >4.40kN/m, transverse tensile strength >2.20kN/m, air permeability >3.4μm/Pa? s, aperture ≤50μm, medical device packaging when opened without paper wool. Short fiber and fine fiber will cause the medical device packaging is not clean stripping situation when opened, so it is necessary to control the amount of broadleaf wood pulp, improve the paper in all aspects of performance.
PAE has an important effect on the breathability of medical dialysis paper. Some medical packaging needs to pass through high pressure steam before use, which requires medical dialysis paper to have a certain wet strength. Wet strength agent can be added in production, and PAE is a widely used wet strength agent at present.
Dry strength agent has important influence on the breathability of medical dialysis paper. Medical device packaging should have certain mechanical strength in the process of production, transportation and use. Commonly used dry strength agents are mainly anion, cationic starch, cationic polyacrylamide, amphoteric polyacrylamide or graft copolymer.
Sizing has an important effect on the breathability of medical dialysis paper. Packaging products are required to be opened without paper hair, and the unwrapping structure should be continuous and uniform, and do not pollute medical devices after opening. Therefore, it is necessary to ensure that the heat sealing strength is moderate (0.80~8.00N/15mm), and further improve the internal bonding strength and surface properties of medical dialysis paper. Surface sizing is one of the commonly used methods to improve the surface properties.
Pressure light has an important effect on the breathability of medical dialysis paper. The equivalent aperture has a great impact on the bacterial isolation performance of medical packaging materials. It is proposed in ISO11607, EN868 series and GB19633 standards that the average aperture of 10 pieces of paper should be less than 35μm, and no piece should be ≥50μm. Dimming can improve the surface properties of the paper, reduce the thickness of the paper, reduce the aperture of the paper, reduce the permeability of the dialysis paper.
Air permeability is an important index of medical dialysis paper, and medical device packaging needs to have certain air permeability. Experiments show that: in the production process of medical dialysis paper, the beating degree, ratio of pulp, wet strength agent, tensile strength agent and sizing agent will have an impact. Low needle-width beating degree, higher proportion of broadleaved wood pulp, appropriate sizing type and low pressure can improve the breathability of the paper. However, as the packaging material of medical instruments, the bacterial-resistance and mechanical properties of the medical dialysis paper are also important indicators, which should be considered comprehensively in the actual production. When the beating degree of conifer wood pulp is 22°SR, the beating degree of broad leaf wood pulp is 25°SR, the ratio of needle width is 75%:25%, the dosage of PAE is 1.0%, no tensile strength agent is added, the sizing agent is PVA and cationic starch 1:1 mixture, the curing for 30min, and the pressure of 3kg/cm, the dialysis paper has good mechanical properties. At the same time, the paper breathability is 5.1μm/Pa? s, equivalent aperture <15μm.