KR101866571B1 - Biodegradable Non-woven Web, Method for Manufacturing The Same, and Blood Filter Using The Same - Google Patents

Abstract

A nonwoven web which can satisfy all the performances required for the blood filter when it is used for the production of a blood filter for leukocyte removal as well as a biodegradable and biocompatible fiber, The filter is started. The nonwoven web of the present invention comprises fibers having an average diameter of 3 탆 or less and a diameter coefficient of variation of 30 CV% or less, said fibers being at least one selected from the group consisting of polylactic acid, polycaprolactone, and polyglycolic acid Of an aliphatic polyester.

Description

TECHNICAL FIELD [0001] The present invention relates to a biodegradable nonwoven web, a method of manufacturing the same, and a blood filter using the biodegradable nonwoven web,

The present invention relates to a nonwoven web, a method for producing the same, and a blood filter using the same. More particularly, the present invention relates to a nonwoven web comprising a biodegradable and biocompatible fiber, To a non-woven web capable of satisfying all the performances required for a blood filter, a manufacturing method thereof, and a blood filter using the same.

When blood or red blood cell concentrates containing white blood cells are transfused, side effects such as headache, vomiting, chills, fever, virus infection, and allogeneic antigen sensitization may occur. In order to prevent such side effects, it is necessary to remove the white blood cells present in the blood to be transfused before transfusion.

Among the methods for removing leukocytes from the blood include a centrifugal separation method in which white blood cells are separated by rotating the blood at a high speed, a filter method in which leukocytes are adsorbed and separated by allowing the blood to pass through the filter, There is a method of text to inhale and remove the separated white blood cell layer. Among them, a filter method having excellent leukocyte separation performance, easy operation and low cost is widely used.

Various types of substrates have been used for the blood filter used in the filter method. As substrates having a high porosity (indicating the degree of pore formation) and an pore size (pore diameter) of 10 m or less, A meltblown nonwoven fabric made of ultrafine fibers having a diameter of not more than 100 nm is widely used.

The main raw materials generally used for producing the microfine fibers were synthetic polymers such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT).

However, the polyethylene terephthalate may be hydrolyzed or depolymerized with a carboxyl group and a high hydroxyl group even in a very small amount of water absorption, and its molecular weight and degree of polymerization may be greatly lowered. If the molecular weight is reduced, the physical properties are lowered and the flowability of the molten resin is increased, and the resin may flow down from the spinning nozzle. In addition, a phenomenon (Fly) in which fibers are cut and blown by a high velocity air stream may occur during melt blowing.

In addition, antimony trioxide (Sb ₂ O ₃ ), which is a catalyst that is essentially used for the synthesis of polyethylene terephthalate, has recently been defined as a harmful inorganic substance and can not be applied to medical materials such as blood filters.

On the other hand, polybutylene terephthalate has an excellent physical property of polyethylene terephthalate, and its glass transition temperature (Tg) is lower than that of polyethylene terephthalate by at most 40 ° C, which is advantageous in that the crystallization rate is relatively high and the dimensional change is small . However, since the crystallization speed is excessively high, there is a disadvantage that it is difficult to control the spinning conditions, particularly the stretching conditions, for producing microfine fibers.

Above all, a blood filter made of a synthetic polymer such as polyethylene terephthalate and polybutylene terephthalate is classified as a medical waste to be discarded after a single use, but does not biodegrade and causes environmental pollution.

The importance of biodegradable polymers has been emphasized in response to the demand for environment protection. However, it has been recognized that it is almost impossible to manufacture nonwoven fabrics made of microfine fibers of 3 탆 or less required in the blood filter field because most of the biodegradable polymers are brittle and lack of extensibility. As a result, Research and development of blood filters using polymer have not been done yet.

Accordingly, the present invention is directed to a biodegradable nonwoven web capable of preventing problems caused by limitations and disadvantages of the related art, a method of manufacturing the same, and a blood filter using the same.

One aspect of the present invention is to provide a biodegradable and biocompatible fiber as well as to a blood filter for the production of a leukocyte-removing blood filter, wherein the performance required for the blood filter, for example high leukocyte removal rate and erythrocyte recovery rate Thereby providing a nonwoven web that can satisfy all of these requirements.

Another aspect of the present invention is to provide a biodegradable and biocompatible fiber as well as to a blood filter for the production of a leukocyte removal blood filter, And a method for manufacturing the nonwoven web.

Another aspect of the present invention is to provide a blood filter having optimal biocompatibility and being capable of biodegradation upon disposal after a single use.

Further features and advantages of the invention will be described hereinafter, and will in part be obvious from the description. Alternatively, other features and advantages of the invention may be learned through practice of the invention.

According to one aspect of the present invention, there is provided a fiber having an average diameter of 3 탆 or less and a diameter variation coefficient of 30 CV% or less, wherein the fibers are selected from the group consisting of Polylatic Acid (PLA), Poly Carprolacton And at least one aliphatic polyester selected from the group consisting of polyglycolic acid (PGA) and polyglycolic acid (PGA).

In another aspect of the present invention, there is provided a method for preparing a dope comprising preparing a dope comprising at least one aliphatic polyester selected from the group consisting of polylactic acid, polycaprolactone, and polyglycolic acid; Radiating the dope through a radiation module for fiber formation; And collecting the fibers, wherein the spinning step comprises: injecting a compressed gas into the dope; And ejecting the dope together with the compressed gas from the spinning module, wherein the spinning module has holes of 30 to 50 HPI (hole per inch), each of the holes having a diameter of 0.2 to 0.3 mm , And a discharge amount of the dope discharged from the radiation module is 0.1 to 0.15 g / hole / minute.

In yet another aspect of the present invention, there is provided a fiber comprising fibers having an average diameter of 3 탆 or less and a diameter variation coefficient of 30 CV% or less, wherein the fibers comprise at least a group selected from the group consisting of polylactic acid, polycaprolactone, and polyglycolic acid A blood filter comprising a biodegradable nonwoven web comprising one aliphatic polyester is provided.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the invention as claimed.

The present invention has the following effects.

First, since the nonwoven web according to the present invention has biodegradability, the blood filter manufactured from the nonwoven web of the present invention does not cause environmental problems even if it is used once for blood filtration such as leukocyte removal and hemodialysis .

Second, since the nonwoven web according to the present invention has optimal biocompatibility, the blood filter manufactured from the nonwoven web of the present invention can minimize the damage of the red blood cells and minimize the hemolysis rate.

Third, since the nonwoven web according to the present invention has a fiber diameter of 3 μm or less and an optimum pore diameter and a lamination density, the blood filter manufactured using the nonwoven web of the present invention can achieve high leukocyte removal rate and red blood cell recovery rate.

A blood filter having such characteristics can be used in a leukocyte removal filter device.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
1 is a SEM photograph showing a surface of a biodegradable nonwoven web prepared according to an embodiment of the present invention,
2 is a SEM photograph showing a cross section of a biodegradable nonwoven web prepared according to an embodiment of the present invention.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Therefore, the present invention encompasses all changes and modifications that come within the scope of the invention as defined in the appended claims and equivalents thereof.

Hereinafter, a biodegradable nonwoven web according to an embodiment of the present invention, a method of manufacturing the same, and a blood filter using the same will be described in detail.

The nonwoven web of the present invention comprises fibers having an average diameter of 3 탆 or less and a diameter variation coefficient of 30 CV% or less. Preferably, the fibers of the nonwoven web have an average diameter of 0.5 to 3 μm and a diameter variation coefficient of 30 CV% or less. The diameter variation coefficient is a percentage of the standard deviation of the average diameter of the fibers.

If the average diameter of the fibers is less than 0.5 占 퐉, the pressure loss during filtration of the blood is high, and the weak strength of the fibers may cause the cutting of fibers and the generation of hair, and the cut fibers are included in the blood Transfusion side effects may result. On the other hand, when the average diameter of the fibers exceeds 3 탆, the leukocyte removal rate of the nonwoven web may be lowered because the probability of the fibers contacting the leukocyte is lowered.

According to the present invention, since the diameter variation coefficient of the fibers is 30 CV% or less, a uniform blood flow can be ensured throughout the nonwoven web, and as a result, the nonwoven web can exhibit excellent filtration efficiency and filtration performance .

The fibers can be continuous or discontinuous fibers, and the fibers are randomly dispersed and laminated to form a three-dimensional nonwoven web. Voids are formed between the fibers of the nonwoven web.

According to the present invention, the fibers constituting the nonwoven web may be at least one selected from the group consisting of polylactic acid (PLA), polycaprolactone (PCL), and polyglycolic acid (PGA) Of an aliphatic polyester.

According to one embodiment of the present invention, the aliphatic polyester has a melt index of 70 to 900 g / 10 min (210 ° C), and the melting point of the aliphatic polyester measured by DSC (Differential Scanning Calorimeter) to be.

Polylactic acid, polycaprolactone, and polyglycolic acid are representative biodegradable polymers. Polylactic acid (PLA), which is most commonly used as a biodegradable material, is a major component of starch or sugar obtained from corn, sugar cane, potatoes and the like, and has been proven to be biocompatible through FDA certification.

As mentioned above, it has been recognized that it is almost impossible to manufacture nonwoven fabrics made of ultrafine fibers of 3 μm or less required in the blood filter field because most biodegradable polymers are brittle and lack of extensibility. However, breaking this prejudice, Applicants have found that by changing the process conditions of conventional meltblown processes that have been used in the production of nonwoven webs for blood filters, as described below, A nonwoven web composed of aliphatic polyester fibers having an average diameter of 3 μm or less and a diameter variation coefficient of 30 CV% or less can be produced.

Optionally, the fibers may further comprise at least one of polyethylene terephthalate and polybutylene terephthalate. In this case, the content of at least one of the polyethylene terephthalate and the polybutylene terephthalate should be less than 50 wt% (that is, the content of the aliphatic polyester should be more than 50 wt%), preferably 10 wt% (That is, the content of the aliphatic polyester should be 90 wt% or more).

Hereinafter, the structure of the nonwoven web of the present invention will be described more specifically.

As described above, since the nonwoven web of the present invention has a three-dimensional structure formed of ultrafine fibers having an average diameter of 3 μm or less and a diameter variation coefficient of 30 CV% or less, the nonwoven web can have excellent filtration efficiency because of its wide surface area.

In addition, since the nonwoven web of the present invention has a three-dimensional structure formed of ultrafine fibers having an average diameter of 3 μm or less and a diameter variation coefficient of 30 CV% or less, it is possible to remove white blood cells having a size of 12 to 25 μm at a high rate It can have a proper pore size. The size of the pores may be represented by the diameter of the pores (hereinafter "pore"), according to one embodiment of the present invention, the nonwoven web has an average pore size of 5-12 μm and a maximum pore size of 8-25 μm Thereby selectively adsorbing and removing only leukocytes from the blood components.

If the maximum pore size of the nonwoven web is less than 8 mu m, erythrocytes having a size of 6 to 8 mu m can not pass through the nonwoven web, and the pressure loss is increased to decrease the passage speed of the blood, have. On the other hand, when the maximum pore size of the nonwoven web exceeds 25 탆, leukocytes having a size of 12 to 25 탆 may pass through the filter, thereby lowering the leukocyte removal rate of the nonwoven web.

The nonwoven web may have a weight of 5 to 50 g / m 2, and more preferably 10 to 30 g / m 2. In addition, the nonwoven web may have an average thickness of 0.05 to 0.20 mm, and more preferably an average thickness of 0.08 to 0.12 mm. The nonwoven web having the weight and the average thickness in the above range can be obtained by suitably adjusting the spinning temperature, the air pressure, the gap between the spinneret and the collector, and the like.

The nonwoven web may have a Critical Wetting Surface Tension (CWST) of 63 to 120 dyne / cm. More preferably, the nonwoven web may have a CWST of 80 to 120 dyne / cm.

The CWST drops a series of liquids whose surface tension varies in the range of 2 to 4 dyne / cm (mN / m) onto the surface of the sample in the form of droplets, and then observes the respective liquid droplets, . CWST using a unit of dyne / cm is defined as the average of the surface tension of the absorbed liquid and the surface tension of the unabsorbed liquid. If a liquid having a lower surface tension than the CWST of the nonwoven web is spontaneously wetted with the nonwoven web upon contact with the nonwoven web. For example, a nonwoven web having a CWST lower than water having a surface tension of 72 dyne / cm is not wetted upon contact with water. Therefore, the CWST of the nonwoven web can be regarded as a measure of the hydrophilicity, and the higher the CWST, the higher the hydrophilicity of the nonwoven web.

If the affinity of the nonwoven web to blood is too weak, the blood treatment time is too long to be practical. If the affinity with blood is too strong, not only leukocytes but also red blood cells and platelets are adsorbed and removed. If the CWST of the nonwoven web is less than 63, the affinity with the blood is too low and the blood treatment time is too long, so that the blood can be coagulated and the blood collides with the red blood cells and the fibers when the blood passes through the pores of the nonwoven web As a result, the level of LDH (Lactate Dehydrogenas), which indicates the degree of damage to the red blood cells, is increased, and as a result, the erythrocyte life span can be shortened sharply. On the other hand, when the CWST of the nonwoven web exceeds 120, it is impossible to obtain a blood product having a level required in the industry due to adsorption of red blood cells and platelets.

The blood filter of the present invention includes the above-described nonwoven web of the present invention.

The nonwoven web in the blood filter has a lamination density of 0.07 to 0.17 g / cm3. The lamination density is expressed in terms of the mass of the entire nonwoven web constituting the filter as a whole volume of the case of the blood filter.

If the density of the nonwoven web is less than 0.07 g / 백, the leukocyte can easily pass through the filter, so that it can not have the leukocyte removal rate required by the industry, and in particular, As the blood passes through the filter, the red blood cell recovery rate and the leukocyte removal rate do not show a constant value, which can cause severe performance deviations. On the other hand, when the density of the nonwoven web exceeds 0.17 g /,, the space between the adjacent nonwoven webs becomes narrow, so that red blood cells having a size of 6-8 탆 fail to smoothly pass through the nonwoven webs, And a decrease in erythrocyte recovery may be caused.

The blood filter manufactured in this way has an excellent leukocyte removal rate of 98% or more and an erythrocyte recovery rate of 85% or more. Accordingly, the blood filter can be used as a blood purifying apparatus for blood transfusion and blood donation requiring a good leukocyte removal rate and a red blood cell recovery rate.

Hereinafter, a method of manufacturing a nonwoven web according to an embodiment of the present invention will be described in detail.

First, a dope comprising at least one aliphatic polyester selected from the group consisting of polylactic acid, polycaprolactone, and polyglycolic acid is prepared. Optionally, the dope may further comprise at least one of polyethylene terephthalate and polybutylene terephthalate. In this case, the content of at least one of polyethylene terephthalate and polybutylene terephthalate should be less than 50 wt.% (That is, the content of the aliphatic polyester should be more than 50 wt.%), Preferably not more than 10 wt.% (That is, the content of the aliphatic polyester should be 90 wt% or more).

The dope is then emitted through the radiation module. The step of radiating includes ejecting a compressed gas to the dope and discharging the dope together with the compressed gas from the spinning module.

According to the present invention, the spinning module has holes of 30 to 50 HPI (hole per inch), each of the holes has a diameter of 0.15 to 0.35 mm, and the discharge amount of the dope discharged from the spinning module is 0.1 to 0.15 g / hole / minute.

In the case of a dope not containing an aliphatic polyester, even if the number of holes of the spinning module is less than 30 HPI as in the prior art, there is no problem in emitting the dope. However, in the case of a dope containing an aliphatic polyester lacking brittleness and extensibility, if the number of holes of the spinning module is less than 30 HPI as in the prior art, a problem arises that the spinning pressure becomes large, Occurs. On the other hand, if the number of holes in the spinning module exceeds 50 HPI, the holes are too close to each other, resulting in a die swell caused by polymer particles, so that the non-solidified adjacent polymers are clogged with each other, As a result, defects occur on the surface of the nonwoven web.

In the case of a dope not containing an aliphatic polyester, there was no problem in producing fibers having a diameter variation coefficient of 30 CV% or less even when the diameter of the hole of the spinning module exceeds 0.35 mm as in the prior art. However, when the dope of the present invention containing an aliphatic polyester is radiated, if the diameter of the hole exceeds 0.35 mm, the amount of the dope discharge can not be controlled uniformly, and as a result, the uniformity of the fiber diameter is lowered, The coefficient exceeds 30 CV%. On the other hand, if the diameter of the hole of the radiation module is less than 0.15 mm, the radiation pressure becomes so large as to cause damage of the radiation module, so that radiation is almost impossible.

In the case of the dope containing no aliphatic polyester, there is no problem in producing microfine fibers of 3 탆 or less even when the discharge amount of the dope exceeds 0.15 g / hole / minute as in the conventional case. However, when the dope of the present invention containing an aliphatic polyester is radiated, if the amount of the above-mentioned dope discharge exceeds 0.15 g / hole / minute, the fiber can not be stretched due to brittle characteristic peculiar to the polymer, It was found that microfibers could not be produced. On the other hand, if the amount of the dope discharge is less than 0.1 g / hole / min, the fibers formed as a result of the dope discharge are not collected by the collector, and the fibers are scattered and can not be used as a filter.

According to one embodiment of the present invention, the spinning step is performed at 230 to 260 ° C, and the compressed gas has a pressure of 0.7 to 1.5 kgf / cm 2.

If the spinning temperature is less than 230 캜, the spinning temperature is too low to sufficiently stretch the resulting fibers. As a result, ultrafine fibers having a diameter of 3.0 탆 or less can not be obtained, and the binding force between the fibers collected on the collector is weakened It is difficult to satisfy the required filter performance. On the other hand, when the spinning temperature is higher than 260 ° C, the bonding force between the fibers collected on the collector due to the excessive temperature becomes too strong, so that voids having a proper pore size can not be formed and a paper- May not proceed smoothly.

On the other hand, when the pressure of the compressed gas is less than 0.7 kgf / cm < 2 >, microfine fibers having a diameter of 3.0 mu m or less can not be obtained due to insufficient elongation of the fibers, while the pressure of the compressed gas is 1.5 kgf / The fibers may be blown when they are exceeded, and the nonwoven web bonded to the blood filter manufacturing can not be produced due to the excessive hair.

Under the above conditions, the dope discharged from the spinning module is collected on the collector while forming the microfine fibers to form the nonwoven web.

Hereinafter, the present invention will be described in detail with reference to examples and comparative examples. It should be noted, however, that the following examples are intended to assist the understanding of the present invention, and the scope of the present invention should not be limited thereby.

Example  One

A dope was prepared using a polylactic acid (PLA) resin having a melt index of 80 g / 10 min (210 캜) and a melting point of 164 캜 as measured by DSC, and then melt kneaded using a meltblown method at a density of 30 g / Weight, an average thickness of 0.15 mm.

Holes of 40 HPI were formed in the spinning module used, each hole had a diameter of 0.25 mm, and the discharge amount of the dope was 0.107 g / hole / min. The spinning temperature was 245 ° C, the pressure of the compressed gas dispersed in the dope was 1 kgf / cm ² , the air temperature was set 5 ° C higher than the spinning temperature, and the Die to Collector Distance (DCD) was 70 mm.

Example  2

A nonwoven web was produced in the same manner as in Example 1, except that the spinning temperature was 255 占 폚.

Example  3

In addition to the polylactic acid (PLA) resin, a polybutylene terephthalate resin having a melting temperature of 225.3 DEG C, an intrinsic viscosity (IV) of 0.7, and a glass transition temperature of 63 DEG C or lower was contained in the dope in an amount of 10 wt% Was 260 占 폚, a nonwoven web was produced by the same method as in Example 1 described above.

Example  4

In addition to the polylactic acid (PLA) resin, a polyethylene terephthalate resin having a melt temperature of 256 DEG C, an intrinsic viscosity (IV) of 0.52, and a glass transition temperature of 78.0 DEG C or higher was contained in the dope in an amount of 10 wt% Lt; 0 > C, the nonwoven web was produced by the same method as in Example 1 described above.

Comparative Example  One

A nonwoven web was produced in the same manner as in Example 1, except that the spinning temperature was 225 占 폚.

Comparative Example  2

A nonwoven web was prepared in the same manner as in Example 1, except that the spinning temperature was 262 ° C.

Comparative Example  3

A nonwoven web was produced in the same manner as in Example 3, except that the content of the polybutylene terephthalate resin in the dope was 50% by weight.

Comparative Example  4

A nonwoven web was prepared in the same manner as in Example 3, except that the content of the polybutylene terephthalate resin in the dope was 100% by weight.

Comparative Example  5

A nonwoven web was prepared in the same manner as in Example 4, except that the content of the polyethylene terephthalate resin in the dope was 100% by weight and the spinning temperature was 270 캜.

Comparative Example  6

A nonwoven web was prepared in the same manner as in Example 1, except that holes of 25 HPI were formed in the spinning module.

Comparative Example  7

 A nonwoven web was produced in the same manner as in Example 1 except that the diameter of each hole of the radiation module was 0.4 mm.

Comparative Example  8

A nonwoven web was prepared in the same manner as in Example 1, except that the amount of the dope discharged was 0.25 g / hole / min.

The mean diameter and diameter variation coefficient of the fibers of the nonwoven web obtained by the above examples and comparative examples, the average pore diameter and maximum pore diameter of the nonwoven web, the hemolysis rate, the leukocyte removal rate, and the erythrocyte recovery rate were measured using the following methods And the results are shown in Table 3.

Average fiber diameter (탆) and Diameter coefficient of variation ( CV %)

The average diameter and the diameter variation coefficient of the fibers constituting the nonwoven fabric of the blood filter were measured using a scanning electron microscope (model name) and an image analyzer (Image-Pro Plus software, JVC Digital Camera KY-F70B) The diameters were measured and the average diameter and coefficient of variation of the fibers were determined using the measured diameters. At this time, 20 or more measurement specimens were sampled and then measured to determine average diameter and diameter variation coefficient of the fibers.

Diameter variation coefficient (CV%) = (standard deviation / arithmetic mean) × 100

The average pore diameter (占 퐉) and the maximum pore diameter (占 퐉)

The average pore diameter (탆) and the maximum pore diameter of the nonwoven fabric constituting the blood filter were measured using Capillary Flow Porometer (PMI, CFL-1100-AE) according to ASTM F 316-03, D 1129, D 1193, Respectively. Specifically, after sufficiently wetting the specimen with a Galwick solution having a surface tension of 15.9 dyne / cm 2, the pore size was determined by measuring the pressure according to the wet / dry fluid.

d = C τ / p

Where d is the maximum pore diameter (탆), τ is the surface tension of the solution (dynes / cm), p is the differential pressure and C is the constant (0.415 when p is psi units)

Hemolysis rate Hemolytic Test )

The hemolysis rate, which quantitatively evaluates the blood affinity between the blood and the filter, can be obtained by quantitatively measuring the degree of erythrocyte destruction in the blood of the test substance by UV 540 nm by taking the rabbit's (ear) , And this value is expressed as an exponent obtained by subtracting the% hemolysis rate value of the negative control (standard sample: HDPE) known to have no hemolysis rate. Generally, when the index has a value of less than 2, it is not hemolytic and can be used as a medical material such as a nonwoven web for a blood filter.

% Hemolysis rate corrected by blank = {(A ^S -A ^B ) / (A ^T -A ^B )} × 100

(Where A ^S is the absorbance of the sample, A ^T is the absorbance of the diluted blood, and A ^B is the absorbance of the blank)

The hemolytic index Hemolytic Grade 0 - 2 Non-Hemolytic 2 - 5 Slightly hemolytic > 5 Hemolytic

Leukocyte removal rate and erythrocyte recovery rate

The filtration area of the nonwoven web was 62 cm ² , and a plurality of cut nonwoven webs were laminated to form a laminated nonwoven fabric. Then, the laminated nonwoven fabric was inserted into a polycarbonate filter case, and then the case was sealed to prevent blood from leaking to prepare a blood filter. The nonwoven web had a lamination density of 0.119 g / mm < ^{3 &} gt ;. Then, the blood filter was installed on a stand having a height of 2 m and directly connected to a tube through which whole blood was passed to collect blood. After collecting 15 cc of blood before and after filtration, a Multicolor Flow Cyometric Method was used The blood cell counts were measured formally to obtain leukocyte removal rate and erythrocyte recovery rate. The automated hemocyte measuring apparatus measured leukocyte removal rate and erythrocyte recovery rate under the conditions shown in Table 1 below.

division Auto CBC Reference RBC Counter 3.80 to 6.5 M / WBC Counter 4.0 to 11.0 K / WBC differential counter Lym-: 20-45%, Neutro-: 40-75% Hemoglobin (Hb) 11.5 to 18 g / dL Hematocrit (Hct) 37.0 to 50.0% Platelet 150 ~ 40K / l

Blood filter applicability

Considering all of the factors measured by the above methods, the applicability of the non-woven web to the blood filter was evaluated as grade 4 (?: Very good,?: Good,?: Normal, poor: poor).

Polymer radiation
Temperature
(° C) Average
diameter
(탆) diameter
Coefficient of variation
(CV%) Average
Honor
(탆) maximum
Honor
(탆) Hemolytic
Indices leukocyte
Removal rate
(%) Red blood cells
Recovery rate
(%) Blood filter
apply
Possibility Example 1 100% PLA 244 1.47 12.6 6.8 12.7 0 99.7 88.4 ◎ Example 2 100% PLA 255 0.95 14.9 7.6 14.5 0 99.7 87.6 ◎ Example 3 PLA / PBT
(90/10) 260 1.62 16.8 8.1 15.9 1.0 99.7 87.2 ○ Example 4 PLA / PET
(90/10) 260 1.77 13.3 10.0 21.4 1.5 99.7 86.9 ○ Comparative Example 1 100% PLA 225 2.83 20.4 11.3 22.4 0 97.5 90.1 △ Comparative Example 2 100% PLA 262 0.91 51.4 4.3 11.4 0 98.4 90.0 △ Comparative Example 3 PLA / PBT
(50/50) 260 2.30 32.3 12.9 25.6 2.5 98.7 84.3 X Comparative Example 4 100% PBT 260 3.01 42.5 14.3 28.1 2.5 95.3 85.1 X Comparative Example 5 100% PET 270 3.51 49.5 15.4 32.6 3.0 94.2 76.3 X Comparative Example 6 100% PLA 244 3.12 46.3 7.1 15.5 0 96.1 80.3 X Comparative Example 7 100% PLA 244 3.59 52.3 8.4 17.9 0 96.3 78.3 X Comparative Example 8 100% PLA 244 4.25 42.1 7.7 16.5 0 96.7 75.5 X

Claims (10)

delete delete delete delete delete Preparing a dope comprising at least one aliphatic polyester selected from the group consisting of polylactic acid, polycaprolactone, and polyglycolic acid;
Radiating the dope through a radiation module for fiber formation; And
And collecting the fibers,
Wherein the step of radiating comprises:
Spraying compressed gas to the dope; And
And discharging the dope together with the compressed gas from the spinning module,
The radiation module has holes of 30 to 50 HPI (hole per inch)
Each of the holes having a diameter of 0.15 to 0.35 mm,
Wherein a discharge amount of the dope discharged from the radiation module is 0.1 to 0.15 g / hole / minute. The method according to claim 6,
The spinning step is carried out at 230 to 260 < 0 > C,
Wherein the compressed gas has a pressure of 0.7 to 1.5 kgf / cm < 2 >. The method according to claim 6,
Wherein the dope further comprises at least one of polyethylene terephthalate and polybutylene terephthalate. delete delete

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