Non-woven fabric for sterilization packaging

Abstract

The invention discloses a non-woven fabric for sterilization packaging, the non-woven fabric is a laminated non-woven fabric, the surface of the laminated non-woven fabric is provided with rolling points, and the area proportion of the rolling points on the laminated non-woven fabric is 14-22%. The non-woven fabric for sterilization packaging has the advantages of being easy to control in air permeability and high in strength.

Description

Technical Field

[0001] The present invention relates to a non-woven fabric for sterilization packaging. Background Art

[0002] With the rapid development of the medical device industry, medical sterilization packaging materials are widely used. Generally, sterilization packaging materials should meet the following conditions: the sterilizing agent can directly penetrate into the equipment in the package, the air and residual sterilizing agent in the package can be discharged, and external bacteria can be shielded. In addition, it should have certain puncture resistance, tear resistance, moisture resistance and friction resistance.

[0003] However, most of the current sterilization packaging materials on the market are made of sterilization paper or non-woven fabrics without embossing points on the surface. This is because when non-woven fabrics or paper are used as sterilization packaging materials, they need to be laminated with a film first. Although the flat material has better peelability after being laminated with the film, the controllable range of the air permeability of this material is small, and it is difficult to adjust the air permeability level in different use environments. In addition, the strength of the flat surface material is relatively low and the physical tolerance characteristics are poor, which is not conducive to the storage of sharp objects.

[0004] For example, Chinese Patent CN203512323U discloses a sterilization packaging material, which includes a non-woven fabric and a sterilization indicator. Although this material has a high porosity and can maintain the sterilized state inside the material, the surface of this material is a flat structure, and the controllable range of air permeability is small, and it is difficult to adjust the air permeability level in different use environments.

[0005] Another example is Chinese Patent CN217457009U, which discloses a medical breathable sterilization paper-plastic packaging bag. An activated carbon adsorption sheet is arranged on the inner wall of the paper bag to sterilize the inside of the bag body. The activated carbon adsorption sheet and the sterile gauze are separated by a non-woven fabric cover to prevent the sterile gauze and the activated carbon adsorption sheet from directly contacting. Although this material has good air permeability, this sterilization bag is a paper-plastic packaging bag, and the tensile strength of the packaging bag is low. Summary of the Invention

[0006] The purpose of the present invention is to provide a non-woven fabric for sterilization packaging with easy controllable air permeability and high strength.

[0007] The technical solution of the present invention is as follows: The non-woven fabric for sterilization packaging of the present invention is a laminated non-woven fabric, and the surface of the laminated non-woven fabric has embossing points, and the area ratio of the embossing points on the laminated non-woven fabric is 14-22%.

[0008] The beneficial effects of the present invention: The non-woven fabric for sterilization packaging of the present invention has the characteristics of easy controllable air permeability and high strength. Detailed Embodiments

[0009] The non-woven fabric for sterilization packaging of the present invention is a laminated non-woven fabric. The surface of the laminated non-woven fabric has embossing points, and the area ratio of the embossing points on the laminated non-woven fabric is 14-22%. Generally speaking, the form of the above-mentioned laminated non-woven fabric is not limited in any way. However, considering that the laminated non-woven fabric has high strength, good peelability and air permeability, the structure of the laminated non-woven fabric is preferably spunbond / spunbond / spunbond (SSS), spunbond / meltblown / spunbond (SMS), spunbond / meltblown / meltblown / spunbond (SMMS), spunbond / spunbond / meltblown / meltblown / spunbond (SSMMS). Considering the low air permeability of the laminated non-woven fabric, the structure of the laminated non-woven fabric is more preferably that the middle layer contains a meltblown layer, and the structure of the laminated non-woven fabric is more preferably spunbond / meltblown / spunbond (SMS), spunbond / meltblown / meltblown / spunbond (SMMS), spunbond / spunbond / meltblown / meltblown / spunbond (SSMMS).

[0010] The surface of the laminated non-woven fabric of the present invention has embossing points, which are obtained by processing with an embossing roll when processing the laminated non-woven fabric, and the embossing points are evenly distributed on the surface of the non-woven fabric. The fabric surface compactness at the embossing points is good, so that the non-woven fabric has high strength and low air permeability. Therefore, the present invention controls the air permeability of the non-woven fabric by the proportion of the embossing point area and the pressure of subsequent calendering processing. The area ratio of the embossing points on the laminated non-woven fabric must be controlled within the range of 14-22%. If the ratio is greater than 22%, it means that the surface of the non-woven fabric is too compact and there is no air permeability at the embossing points, resulting in poor air permeability of the non-woven fabric. When the non-woven fabric is used as a sterilization packaging material, the sterilant is difficult to infiltrate into the interior of the packaging material; if the ratio is less than 14%, the non-woven fabric is too loose and the fabric surface compactness is poor, resulting in too low strength of the laminated non-woven fabric. Considering the good air permeability and high strength of the non-woven fabric, the area ratio of the embossing points on the laminated non-woven fabric is preferably 15-18%.

[0011] The shape of the above-mentioned embossing points is diamond-shaped, and the distance between two adjacent embossing points is preferably 1-1.4 mm. Here, two adjacent embossing points refer to the adjacent embossing points in the width and length directions. When the area ratio of the embossing points on the laminated non-woven fabric is the same, if the distance is too short, the area of a single embossing point is small, the number of embossing points per unit area is too large, and the edge strength of the embossing points is low, so the strength of the laminated non-woven fabric is low; if it is too long, the number of embossing points per unit area is small, the area of a single embossing point is large, and the fabric surface at the embossing points is too compact, resulting in poor air permeability of the non-woven fabric. When the non-woven fabric is used as a sterilization packaging material, the sterilant is difficult to infiltrate into the interior of the packaging material. Considering the high strength and good air permeability of the non-woven fabric, the lengths of the two diagonals of the diamond formed by the arrangement of the embossing points are more preferably 1.1-1.3 mm.

[0012] Since the embossing points on the surface of the non-woven fabric of the present invention are very compact, the number of embossing points is related to the level of air permeability. Therefore, the distribution quantity of the embossing points on the surface of the non-woven fabric is preferably 46-66 per cm2 When the area ratio of the crimp points on the laminated nonwoven fabric is the same, if the number of crimp points is too large, the strength of the laminated nonwoven fabric will be low due to the low edge strength of the crimp points; if it is too small, the number of crimp points per unit area is small, the area of a single crimp point is large, and the fabric surface at the crimp point is too tight, resulting in poor air permeability of the nonwoven fabric. When this nonwoven fabric is used as a packaging material for sterilization, the sterilizing agent is difficult to penetrate into the interior of the packaging material. Considering good air permeability and high strength, the distribution number of crimp points on the surface of the nonwoven fabric is more preferably 51 - 61 pieces / cm 2 。

[0013] The above-mentioned spunbond nonwoven fabric is preferably composed of continuous long fibers with an average diameter of 5 - 15 μm. The average diameter of the long fibers constituting the spunbond nonwoven fabric is preferably within this range, and the obtained laminated nonwoven fabric is dense and has uniform pore sizes, meaning that the bubble point of the maximum pore size decreases. Therefore, the packaging material for sterilization made of this nonwoven fabric can achieve good bacterial barrier properties; if the average diameter of the long fibers is too small, the strength of a single fiber is low, and the tensile strength and puncture strength of the obtained laminated nonwoven fabric are poor; if it is too large, a single fiber is thicker, making the density of the laminated nonwoven fabric too sparse. When this laminated nonwoven fabric is used as a packaging material for sterilization, the pore size uniformity of the material is low and the bacterial barrier property is poor. Considering the strength, density, and uniformity of the laminated nonwoven fabric, the spunbond nonwoven fabric is more preferably composed of continuous long fibers with an average diameter of 7 - 12 μm.

[0014] The above-mentioned meltblown nonwoven fabric is preferably composed of ultra-fine fibers with an average diameter of 0.3 - 3 μm. If the fiber diameter is too large, the distance between fibers will be too large, the pore size of the obtained meltblown nonwoven fabric will be too large, and the pore size uniformity will decrease, resulting in too high air permeability of the laminated nonwoven fabric. When this laminated nonwoven fabric is used as a packaging material for sterilization, the bacterial barrier property of the packaging material is poor; if the average fiber diameter is too small, the pore size of the obtained meltblown nonwoven fabric will be too small and the air permeability will become poor. Considering that the laminated nonwoven fabric has better air permeability and the packaging material for sterilization has better bacterial barrier properties, the above-mentioned meltblown nonwoven fabric is more preferably composed of ultra-fine fibers with an average diameter of 0.5 - 2 μm.

[0015] The air permeability of the laminated nonwoven fabric of the present invention is preferably 5 - 50 s / 100 ml. If the air permeability of the laminated nonwoven fabric is too low, when this laminated nonwoven fabric is used as a packaging material for sterilization, the gas exchange during the sterilization process is poor, and the sterilization treatment does not penetrate into the interior of the packaging material; if the air permeability is too high, the bacterial barrier property of the packaging material for sterilization decreases, and bacteria easily invade the packaging material. Considering that the packaging material for sterilization has better bacterial barrier properties, the air permeability of the laminated nonwoven fabric of the present invention is more preferably 10 - 30 s / 100 ml.

[0016] The average pore size of the laminated non-woven fabric of the present invention is preferably 0.3 to 20 μm. If the average pore size is too low, the fiber gaps are excessively narrow, that is, the air permeability of the non-woven fabric is low. When the laminated non-woven fabric is used as a sterilization packaging material, gas exchange is poor during the sterilization process, and the sterilization treatment does not penetrate into the interior of the packaging material. If the average pore size is too high, the distance between the fibers is too large, and the laminated non-woven fabric is not dense, so it is difficult to block the invasion of bacteria and it is difficult to maintain the sterilized state. Considering that the sterilization packaging material has better bacteria barrier properties and air permeability, the average pore size of the laminated non-woven fabric of the present invention is more preferably 0.5 to 15 μm.

[0017] The tensile strength of the laminated non-woven fabric of the present invention is preferably 30 to 300 N / 25 mm, and more preferably 50 to 250 N / 25 mm. If the tensile strength is too low, in the subsequent production process, it cannot withstand the tension in the processing process, and it is easy to deform when forming the packaging material, and it cannot be used as a sterilization packaging material. If the tensile strength is too high, it means that the fibers in the non-woven fabric are too tight and the tension of the non-woven fabric is too large, which will cause the non-woven fabric to deform or even break.

[0018] The preparation method of the non-woven fabric for sterilization packaging of the present invention includes the following steps:

[0019] (1) Raw material melting and extrusion: Melting the spunbond raw material and the meltblown raw material respectively, and quantitatively extruding through a metering pump;

[0020] (2) Fiber drawing and web forming: Setting a high-speed air flow to draw the melt to obtain fibers, and evenly laying 5-15 μm spunbond fibers, 0.3-3 μm meltblown fibers, and 5-15 μm spunbond fibers on the mesh belt in sequence to form a fiber web with three or more layers;

[0021] (3) Hot rolling reinforcement: Using a patterned roller with shaped embossing points to roll the fiber web to obtain a laminated non-woven fabric with embossing points arranged, and then passing through a small calender with a rubber roller on one side and a steel roller on the other side for calendering at a calendering pressure of 50-60 kg / cm 2 to make the laminated non-woven fabric more compact, and finally obtaining a compact laminated non-woven fabric with embossing points arranged.

[0022] The present invention is further illustrated by the following examples. However, the protection scope of the present invention is not limited to the examples, and the physical properties in the examples are measured by the following methods.

[0023]

Area ratio of embossing points

[0024] It is taken by a digital microscope with a magnification of 10 times. A square of 1 cm × 1 cm is circled on the surface of the non-woven fabric. The number of rolling points M in this area is counted, and the diagonal lengths L1 cm and L2 cm of a single rolling point are measured. The area S1 of a single rolling point is calculated. The calculation formula for the area ratio W of the rolling points is as follows: W = [(L1 × L2) × 1 / 2 × M] / 1. Using the same method as above, 10 areas are measured and the average value is calculated.

[0025]

Distance between two adjacent rolling points

[0026] It is taken by a digital microscope with a magnification of 10 times. In any area on the surface of the non-woven fabric, the distances L1 μm and L2 μm between two adjacent rolling points in the width direction and the length direction are measured respectively. Using the same method, 10 areas are measured and the average value is calculated.

[0027]

Distribution quantity of rolling points on the surface of non-woven fabric

[0028] A square with a side length of 1 cm is circled on the surface of the laminated non-woven fabric, and the number of rolling points M in this area is directly counted. Using the same method as above, 10 areas are measured and the average value is calculated, which is the number of rolling points per 1 cm. 2 of the rolling points.

[0029]

Average fiber diameter

[0030] It is taken using an SEM device. The filaments with an average fiber diameter of less than 0.5 μm are set at 10,000 times, the filaments with an average fiber diameter of 0.5 μm or more and less than 1.5 μm are set at 6,000 times, and the filaments with an average fiber diameter of 1.5 μm or more are set at 4,000 times. More than 100 fibers are randomly taken, and the diameters of all the fibers are taken. The weight-average fiber diameter (Dw) obtained by the following formula is used as the average fiber diameter:

[0031] Dw = ΣWi·Di = Σ(NiDi2) / (Ni·Di)

[0032] {In the formula, Wi = weight fraction of fiber diameter Di = Ni·Di / ΣNi·Di.}

[0033]

Thickness (μm)

[0034] It is tested according to the JIS L-1906 standard. The thicknesses of 10 parts are measured per 1 m in width, and the average value is obtained.

[0035]

Average pore size

[0036] According to the ASTM F316-03 pore size test standard, a pore size tester of Capillary Flow Porometer (model: CFP-1100AX) from PMI Company is used. After immersing the specimen in the surface wetting liquid, gas pressure is applied from the back of the sample, and the minimum pressure P at which bubbles are observed on the surface of the sample is obtained. The pore size d of the sample is calculated using the following formula: d = 4σ(cosθ) / P.

[0037] In the formula, P: pressure in bar, d: pore size (unit: μm), σ: surface tension of the wetting liquid, θ: contact angle of the liquid on the solid.

[0038] Measure the average pore size at 10 positions along the width direction of the non-woven fabric, and find its average value, which is the average pore size of the laminated non-woven fabric.

[0039]

Tensile Strength

[0040] Tensile strength test is carried out using a tensile tester. A test piece with a width of 50 mm × a length of 200 mm is fixed in such a way that the distance between the clamps is 100 mm, and the measurement is carried out at a speed of 100 mm / minute. Five positions are collected every 1 m in the width direction of the non-woven fabric. Apply a load until the test piece breaks, and find the average value of the strength at the maximum load of the test pieces in the machine direction (MD) and the width direction (CD) respectively, which is the tensile strength of the non-woven fabric.

[0041]

Gurley Permeability (seconds / 100 ml)

[0042] Use a Gurley type densitometer (manufactured by Yasuda Seiki Seisakusho Co., Ltd., "B" type) to measure the air permeation time (unit: s / 100 ml) of 100 ml of air through the non-woven fabric sample at room temperature. Five measurements are carried out, and the average value is calculated.

[0043]

Hydrostatic Pressure Resistance

[0044] Measure according to the JIS L1092 standard. Divide the CD direction into 5 equal parts and the MD direction into 3 equal parts. For a total of 15 points, take a test piece of 20 cm 2 and calculate the hydrostatic pressure resistance from the average value of the measured values.

[0045] Example 1

[0046] (1) Raw material melting and extrusion: Melt the spunbond polypropylene raw material and the meltblown polypropylene raw material respectively, and extrude them quantitatively through a metering pump;

[0047] (2) Fiber drafting and web forming: Set high-speed air flow to draft the melt to obtain fibers. Lay 8μm spunbond polypropylene fibers, 0.8μm meltblown polypropylene fibers, and 8μm spunbond polypropylene fibers evenly on the mesh belt in sequence to form a three-layer fiber web;

[0048] (3) Hot rolling reinforcement: Use a patterned roller with diamond-shaped rolling points to roll the fiber web to obtain a laminated non-woven fabric arranged with diamond-shaped rolling points, and then use a small calender with a rubber roller on one side and a steel roller on the other side to calender at a calendering pressure of 55 kg / cm 2 . The area ratio of the rolling points on the laminated non-woven fabric is measured to be 16%, the distance between two adjacent rolling points in the width direction is 1.2 mm, the distance between two adjacent rolling points in the length direction is 1.2 mm, and the distribution quantity is 56 pieces / cm 2 . The physical properties of the non-woven fabric for sterilization packaging of the present invention are shown in Table 1.

[0049] Examples 2 to 13

[0050] The preparation process is the same as that of Example 1, and the specific formulations and physical properties are shown in Tables 1 and 2.

[0051] Comparative Example 1

[0052] (1) Raw material melting and extrusion: Melt the spunbonded polypropylene raw material and the meltblown polypropylene raw material respectively, and quantitatively extrude them through a metering pump;

[0053] (2) Fiber drawing and forming a web: Set high-speed air flow to draw the melt to obtain fibers, and evenly lay 5-15 μm spunbonded polypropylene fibers, 0.3-3 μm meltblown polypropylene fibers, and 5-15 μm spunbonded polypropylene fibers on the mesh belt in sequence to form a three-layer fiber web;

[0054] (3) Hot rolling reinforcement: Use a patterned roller with diamond-shaped rolling points to roll the fiber web to obtain a laminated non-woven fabric arranged with diamond-shaped rolling points, and then use a small calender with a rubber roller on one side and a steel roller on the other side to calender at a calendering pressure of 55 kg / cm 2 . The area ratio of the rolling points on the laminated non-woven fabric is measured to be 12%, the distance between two adjacent rolling points in the width direction is 1.2 mm, the distance between two adjacent rolling points in the length direction is 1.2 mm, and the distribution quantity is 42 pieces / cm 2 . The physical properties of the non-woven fabric are shown in Table 3.

[0055] Comparative Example 2

[0056] The preparation process is the same as that of Comparative Example 1, and the non-woven fabric is not calendered. The physical properties of the non-woven fabric are shown in Table 3.

[0057] Comparative Example 3

[0058] The preparation process is the same as that of Comparative Example 1, and use a roller with a smooth surface to roll the fiber web. The physical properties of the non-woven fabric are shown in Table 3.

[0059] Table 1

[0060]

[0061] Table 2

[0062]

[0063] Table 3

[0064]

[0065] According to the above tables,

[0066] (1) It can be seen from Example 1 and Example 2 that under the same conditions, the area ratio of the rolling points in the former on the laminated non-woven fabric is within the preferred range, and compared with the latter, the tensile strength of the non-woven fabric in the former is higher.

[0067] (2) It can be seen from Example 1 and Example 3 that under the same conditions, the area ratio of the rolling points in the former on the laminated non-woven fabric is within the preferred range, and compared with the latter, the air permeability of the non-woven fabric in the former is better.

[0068] (3) It can be seen from Example 1, Example 4 and Example 5 that under the same conditions, the distribution quantity of the rolling points on the surface of the laminated non-woven fabric in Example 1 and the distance between two adjacent rolling points are within the preferred range, and the non-woven fabric has good air permeability and high tensile strength.

[0069] (4) It can be seen from Example 1 and Comparative Example 1 that under the same conditions, the area ratio of the rolling points in the latter on the laminated non-woven fabric is too small, and compared with the former, the tensile strength of the non-woven fabric is low.

[0070] (5) It can be seen from Example 1 and Comparative Example 2 that under the same conditions, the latter does not undergo calendering, and compared with the former, the air permeability is extremely poor and it cannot be used as a sterilization packaging material.

[0071] (6) It can be seen from Example 1 and Comparative Example 3 that under the same conditions, the laminated non-woven fabric material of the latter has a structure without rolling points, and compared with the former, the strength of the latter is poor and it has almost no hydrostatic pressure resistance and cannot be used as a sterilization packaging material.

Claims

1. A non-woven fabric for sterilization packaging, characterized in that: The non-woven fabric is a laminated non-woven fabric, and the surface of the laminated non-woven fabric has embossing points, and the area ratio of the embossing points on the laminated non-woven fabric is 14-22%.

2. The non-woven fabric for sterilization packaging according to claim 1, wherein: The shape of the embossing points is diamond-shaped, and the distance between two adjacent embossing points is 1-1.4 mm.

3. The non-woven fabric for sterilization packaging according to claim 1, characterized in that: The number of the rolling points distributed on the surface of the laminated non-woven fabric is 46 to 66 per cm 2 .

4. The non-woven fabric for sterilization packaging according to claim 1, characterized in that: The laminated non-woven fabric is, from top to bottom, a spunbond non-woven fabric, a meltblown non-woven fabric, and a spunbond non-woven fabric.

5. The non-woven fabric for sterilization packaging according to claim 4, characterized in that: The spunbond non-woven fabric is composed of continuous long fibers with an average diameter of 5-15 μm.

6. The non-woven fabric for sterilization packaging according to claim 4, characterized in that: The meltblown non-woven fabric is composed of ultra-fine fibers with an average diameter of 0.3-3 μm.

7. The non-woven fabric for sterilization packaging according to claim 1, characterized in that: The air permeability of the laminated non-woven fabric is 5-50 s / 100 ml.

8. The non-woven fabric for sterilization packaging according to claim 1, wherein: The average pore size of the laminated non-woven fabric is 0.3-20 μm.

9. The non-woven fabric for sterilization packaging according to claim 1, characterized in that: The tensile strength of the laminated non-woven fabric is 30-300 N / 5 cm.

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