KR101626892B1 - Manufacturing method of teflon fablic for artficial blood stent - Google Patents

Abstract

The stent for blood vessels applying the artificial blood vessel according to the present invention is a synthetic blood vessel assembly composed of a cylindrical stent composed of a synthetic blood vessel made of fabric and a metal wire net and closely attached to the inner surface of the artificial blood vessel, The blood vessel is a cylindrical teflon fabric, the thickness of the monofilament is 80 to 90 De, and the strength is 5.24 to 6.67 cN · d when the stretching ratio is 1.12.

Description

Technical Field [0001] The present invention relates to a manufacturing method of a teflon fabric for artificial blood vessels,

The present invention relates to a fabric for artificial blood vessels, and more particularly, to a fabric for artificial blood vessels, which is installed inside or outside of a metallic stent for blood vessels installed in a blood vessel to effectively prevent leakage of blood through the blood vessels, The present invention relates to a method for producing a synthetic teflon fabric for blood vessels.

Background Art [2] Generally, a stent for a blood vessel is a medical instrument used for expanding blood vessels by performing a procedure inside a blood vessel when a disease such as a blood circulation is poor due to narrowing of a blood vessel in the human body due to various diseases occurring in the body. to be.

Such a stent for blood vessels is the so-called Palmaz Type stent for blood vessels shown in U.S. Patent No. 5,382,261.

Such a Palmaz type stent maintains its constant length during contraction and expansion, so that it can be accurately applied to a narrowed blood vessel, but it has a disadvantage that its flexibility is insufficient and its adaptability to a curved blood vessel is lowered .

In addition, there is a so-called Wall Type stent shown in US Pat. No. 4,655,771, which is self-expanding and flexible enough to be adaptable even to narrow and curved blood vessels, There is a problem that the diameter is narrowed in the curved blood vessel.

In addition, the present invention can be applied to a variety of apparatuses, including Korean Patent No. 0240832, Korean Patent No. 0193269, Korean Patent No. 0170219, Korean Patent No. 0170220, Korean Patent Publication No. 1999-85314, Korean Patent Publication No. 1999-9743 and Korean Patent No. 189094 Korean Patent Publication No. 1998-33463, and US Patent No. 6,027,525.

Although the above-described methods for producing a blood vessel stent are somewhat different from each other in terms of the method of manufacturing the stent and the shape thereof, they are all formed by a method of crossing or zigzag moving using an alloy wire having a property of memorizing its own shape They are identical in that they are formed in the shape of a hollow cylindrical body.

In the case of the above-mentioned stents for blood vessels, since the hollow cylindrical bodies constituting the stent are all manufactured by crossing one strand or two strands of wires or by moving them in a zigzag manner, the surface of the stent, that is, In the case where such a stent is applied to a blood vessel, it is possible to expand the stenosed region at an early stage to smoothly achieve the desired purpose.

However, as time goes by, blood sludge generated in the blood vessel is generated and permeates into the inside of the stent through the surface space of the stent, which may vary depending on the size of the disease. In other words, there is a problem that the disease element penetrating into the stent can not be fundamentally blocked.

In order to solve these problems, U.S. Pat. Nos. 5,545,211 and 5,330,500 disclose that a polyurethane coating is applied on the outer surface of the stent in a mesh state, A coating layer of a polyurethane material is formed on the surface of the stent, so that it is possible to prevent the penetration of a tumor or the like generated from the outside of the stent when the stent is implanted in a blood vessel or the like. At this time, placing the mesh on the stent is intended to easily form a coating with polyurethane.

However, in the case of such a stent, since a coating layer such as polyurethane is formed on the outside, penetration of tumor or the like into the stent can be prevented. However, in the inside of the stent, the wire and the mesh constituting the stent are exposed And thus various kinds of debris contained in the blood passing through the stent accumulate as time goes by, so that the desired purpose of the stent can not be achieved in the end.

In order to solve the above-mentioned problems, in recent years, the artificial blood vessels have been used as biocompatible fabrics, more specifically nylon, silk, polytetrafluoroethylene (PTFE), polypropylene (PP), polyurethane (PU), polyethylene terephthalate (PET), polyamide (PA), polyacrylonitrile (PAN), polyethylene (PE), polyester (PES), polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), polysiloxane , Polyvinyl alcohol (PVA), polyglycolic acid (PGA), or polylactic acid (PLA) as the raw materials, have been used in combination with the above stent (see Korean Patent Publication No. 2011-0107236).

However, in the above-mentioned patent, only the biocompatible fabrics are listed for the material of the artificial blood vessels, and the physical properties of the fabric are not specifically disclosed. In particular, if the density of the material selected to impart flexibility is too low, And it is difficult to use it practically, for example, when the density is too high in order to prevent the breakage, the adaptability with the body becomes poor.

In order to solve such conventional problems, the present applicant has proposed a method of producing polytetrafluoroethylene (hereinafter, referred to as "polytetrafluoroethylene "), which is the best material for biosynthesis, through patent application No. 10-2013-73515 (filed on June 26, The present invention provides a stent for a blood vessel to which a high-density cylindrical artificial blood vessel is woven using a PTFE material (hereinafter referred to as " PTFE: Teflon ", hereinafter referred to as " Teflon ") material and a high density of a Teflon fabric artificial blood vessel having a small blood leakage rate and high breaking strength. Teflon fabric The artificial blood vessel of a stent for blood vessels to which a synthetic blood vessel is applied is a cylindrical body woven with a Teflon fabric. The monofilament has a thickness of 90 De, the Teflon fabric has a thickness range of 100 to 150 占 퐉, a burst strength of 4 MPa or more And the blood leakage rate is 10 ml / cm 2 / min or less.

Disclosure of Invention Technical Problem [10] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a method for manufacturing a high-density teflon fabric artificial blood vessel having a high blood- And a method thereof.

In order to accomplish the above object, the present invention provides a method for manufacturing a Teflon fabric for artificial blood vessels, comprising the steps of: forming a filament having a thickness of 80 De to 90 De; and a Teflon fabric having a thickness of 100 to 150 탆 and a blood leakage rate of 10 ml / cm 2 / min or less, and the filament used for the artificial blood vessel teflon fabric has a draw ratio of 1.06 to 1.12.

According to an exemplary embodiment of the present invention, the strength of the filament in the stretch ratio range is 5.66 to 6.67 cN. D. The elongation of the filament is 4.23 to 4.94%.

More specifically, when the filament has a thickness of 80 De and a draw ratio of 1.12, the filament strength and elongation are 6.45 cN d and 4.68%, respectively. When the filament has a thickness of 90 De and the draw ratio is 1.12, And elongation are 5.92 cN.d and 4.27%, respectively.

The artificial blood vessel Teflon fabric manufactured according to the present invention has a high strength, that is, a high density, a high breaking strength, thereby limiting the blood leakage rate, securing its maximum stretching ratio and strength elongation, There is an effect that it is possible to prevent breakage or leakage accident.

1 is a photograph showing a stent for a blood vessel to which a graft of a Teflon fabric according to the present invention is applied.
Fig. 2 is a photograph showing a synthetic blood vessel of a Teflon fabric constituting the present invention. Fig.
Figures 3a, 3b and 3c are photographs showing the winder, straight run, run-off for the preparation of warp of the loom for the practice of the present invention.
Fig. 4 is a photograph showing a woodwind of a loom for carrying out the present invention. Fig.
5 is a photograph showing a lighthouse operation in a loom for practicing the present invention.
6 is a photograph showing a weaving operation in a loom for practicing the present invention;
7 is an optical microscope image and an SEM analysis photograph of the product of the present invention.
8 is an illustration of an artificial blood vessel used for the examination of the dimensions (inner diameter, outer diameter) in the present invention.
FIG. 9 is a photograph of equipment used for measuring the water permeability (blood leakage rate) in the present invention. FIG.
10 is a diagram illustrating the principle of measuring burst strength in the present invention.
11 and 12 are electron micrographs of a surface and a cross section of a Teflon yarn for artificial blood vessels (80 De monofilament) before stretching and a stretch ratio of 1.12 according to the present invention.
13 and 14 are electron micrographs of a surface and a cross section of a Teflon yarn for artificial blood vessels (90 De monofilament) before stretching and a stretch ratio of 1.12 according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The Teflon fabric artificial blood vessels of the present invention apply all materials, processes, equipment, and tests utilized in Applicant's eligible Patent Application No. 2013-73515. However, the stretching test was added separately.

As shown in FIG. 1, a stent for blood vessels 100 to which a synthetic blood vessel is applied according to the present invention comprises a synthetic blood vessel 10 composed of a Teflon fabric and a metal wire, And a metal stent 20 inserted and fixed to the stent 20.

The artificial blood vessel 10 is composed of a cylindrical body having a longitudinal axis as shown in FIG. 2, and the artificial blood vessel 10 of the present invention is directly connected to a knitting machine (loom shown in FIG. 6) The material used in this field is Teflon, which is considered to be the most stable to human body, and it maintains uniform strength and leakage rate throughout the whole artificial blood vessel surface. The thickness of the monofilament of the Teflon fabric is preferably in the range of 70 to 400 Da (denier), preferably 80 De or 90 De, in consideration of the breaking strength and flexibility. In the exemplary embodiment of the present invention, a monofilament of 90 De was mainly selected.

Hereinafter, the material, manufacturing process, physical properties, and the like of the artificial blood vessel 10 according to the present invention will be described in detail.

1. Material and manufacturing process of PTFE yarn

Since the artificial blood vessel is a medical product inserted into the human body, its material should be chemically and biologically stable. Teflon yarn most suitable for this purpose is selected, and a raw material in the form of a yarn is required to manufacture artificial blood vessels by a weaving method . However, since Teflon is not spinnable, it is impossible to produce a circular yarn such as nylon or polyester, and it is made into a film.

Teflon yarn manufacturing process begins by preparing Teflon in the form of a film, cutting it into several strands again, stretching it, and then proceeding in the order of twisting and winding. Therefore, the cross-sectional shape of the Teflon yarn is in a state in which the shape of the ribbon is twisted. In the case of too thin yarn, yarns are produced at around 400 Da because yarn is generated in the drawing and yarn processing.

In the present invention, 400De yarn was first obtained and tested. However, since the yarn is too thick, the quantitative target such as tear strength and leakage rate can be attained in the tentative article, but it is deemed unsuitable for use as artificial blood vessel in terms of thickness and flexibility , 90De, and used for artificial blood vessel weaving.

2. Construction of Weaving Equipment

Artificial blood vessels are woven with narrow width loom rather than regular woven, and weaving method is also different from general weaving. Therefore, a dedicated narrow loom for the fabrication of artificial blood vessels and accompanying equipment (winder, junggi, tongkyeong, etc.) are needed.

First, preliminary weaving test with 400De of Teflon yarn using conventional narrow loom showed poor weirability and difficulty in securing physical properties. Therefore, a new weaving loom was newly designed, manufactured and installed so as to be suitable for weaving of artificial blood vessels. It also has attached facilities and checks and corrects the problems in the weaving process.

Weaving is done in the following order.

- Fabric design: Design the texture, width, and density of the fabric to suit the purpose.

- Slope preparation (winder, straight run, run) (see Figures 3a, 3b, 3c)

The winder is a process of sanding the yarn, winding the length of the desired length of yarn by the desired length of yarn, and making the slope according to the design table. If necessary, the slope is adjusted through doubling and finally the slope preparation .

- Preparing weft (winding machine): Preparing weft means winding a yarn in a woodwind. A woodwind wound around the yarn enters the shuttle and performs a reciprocating motion. The necessary equipment is a woodwind, a winding machine, There is a shuttle.

Woodwind: The woodwind shown on the right side of FIG. 4 was small as a woodwind before the improvement, and the length of the winding of the yarn was small, which affected the quality, and the size was increased as shown on the left side of FIG.

Spinning machine: At first, we worked with a manual winding machine that depends on the winder, but the winding condition of the yarn was spiked to cause defects in weaving and quality of products. The automatic winding machine was manufactured and its winding condition was good. The city was omitted.

Shuttle: A shuttle is a weft feeder that inserts a wood-wrapped yarn and reciprocates across it. Therefore, the yarn tension of the yarn should be constant, and the friction surface should be a smooth surface as well as a small portion of friction with the warp. The city was omitted.

- Lighthouse and weaving

5 and 6, respectively.

3. Weaving test

1) Weaving condition setting test

- condition test using spherical weaving machine

Since the weaving of a cylindrical artificial blood vessel using a Teflon yarn was attempted for the first time and there was almost no information about it, a weaving test was performed under various conditions to set a basic weaving condition. The weaving machine used was a commonly used weaving machine and the yarn used Teflon 400De which was initially obtained, and PET 50De was woven together for reference. Table 1 shows the weaving conditions.

No. Bamboo shoots Width (mm) Density (Picks / inch) Thickness (mm) Remarks slope Weft slope Weft One








Teflon
400De PET
50De 14.7 90 84 0.33 Oblique number
(105Ends) 2 Teflon
400De 16.86 85 60 0.41 Oblique number
(114Ends) 3 PET
50De 16.25 88 80 0.36 Oblique number
(113Ends) 4 Teflon
400De 16.13 91 56 0.40 Oblique number
(116Ends) 5 Teflon
400De 16.05 90 63 0.41 Oblique number
(115 Eds) 6 PET
50De 15.07 96 40 0.30 Oblique number
(105Ends) 7 Teflon
400De 15.58 94 53 0.40 Oblique number
(115 Eds) 8 Teflon
400De 16.35 90 54 0.42 Oblique number
(116Ends) 9 PET
50De 15.1 85 52 0.31 Oblique number
(102nds) 10 PET
50De 15.15 87 44 0.30 Oblique number
(104Ends) 11 PET
50De 16.5 89 160 0.35 Oblique number
(116Ends)

Weaving condition (preliminary work for condition setting of spherical loom)

- Condition test using new loom

On the other hand, a general loom requires a high-density weaving, a problem that it is difficult to reduce the thickness due to a low tension, and the like. However, instead of paying a high conversion cost, a new loom suitable for development of the present invention is designed Respectively. Table 2 shows the weaving conditions.

No. Bamboo shoots Width (mm) Density (Picks / inch) Thickness (mm) Remarks slope Weft slope Weft 1-1
Teflon
400De
Teflon
400De 14.7 90 25 0.30 - Pin yarn when weaving
- Workability and poor quality 1-2 13.5 97 50 0.31 1-3 13.35 97 75 0.31 1-4 12.75 101 100 0.45 2-1
Teflon
400De
Teflon
400De 18.39 103 25 0.32 2-2 17.33 112 50 0.41 2-3 17.05 112 75 0.43 2-4 17.05 112 85 0.46 2-5 16.45 114 96 0.46 3-1 Teflon
400De Teflon
400De 17.4 112 25 0.38 - Teflon Yarn Continuous
- Pin yarn occurs during continuous yarn 3-2 17.3 112 50 0.40 4-1
PET
50De
PET
50De 13.75 103 40 0.09 - Insufficient number of incidents
- defective fabric
- Excessive weaving axis 4-2 14 99 50 0.09 4-3 14.5 96 65 0.09 4-4 14.5 96 75 0.09 5-1
PET
50De
PET
50De 18.55 110 50 0.1 - Bad slope preparation process
- Nonuniformity of warp tension
- Fabric width changes severely 5-2 19.25 107 80 0.1 5-3 20.2 101 90 0.11 5-4 20.1 101 100 0.11 5-5 20.95 96 110 0.11 6-1
PET
50De
PET
50De 20.25 127 90 0.16 6-2 19.25 133 100 0.2 6-3 19.25 133 110 0.23 6-4 19.75 130 120 0.22 7-1
Teflon
90De
Teflon
90De 14.75 175 90 0.18 7-2 14.75 175 100 0.18 7-3 14.25 180 120 0.21 7-4 14.2 180 150 0.22 7-5 14.35 177 70 0.22 8-1 Teflon
90De Teflon
90De 1.52 167 170 0.24 9-1 PET
50De PET
50De 51.25 118 123 0.11

Weaving conditions (preliminary work for setting the condition of the new loom)

Using the newly installed loom, various preliminary tests were conducted as shown in Table 2, and the density range of warp and weft suitable for the artificial blood vessels was set.

On the other hand, Teflon 400De was considered to be unsuitable for artificial blood vessels in terms of the thickness and flexibility of the woven fabric, and 90De of Teflon was used for weaving.

The fabric of the fabric was woven in plain weave, which is the most suitable tissue for achieving good burst strength and leakage rate.

2) Development test for the present invention goal

The warp and weft density set through the preliminary test were weighed under the conditions shown in Table 3 below, and their properties were checked.

No. Bamboo shoots Width (mm) Density (Picks / inch) Thickness (mm) Remarks slope Weft slope Weft 10-1
Teflon
90De
Teflon
90De 15.56 205 150 0.12

250Ends 10-2 15.64 205 160 0.13 10-3 15.71 205 170 0.13 10-4 15.87 205 180 0.13 10-5 15.87 205 200 0.14 11-1
Teflon
90De
Teflon
90De 13 234 150 0.14
240Ends 11-2 13 234 162 0.14 11-3 13 234 170 0.14 11-4 13.1 234 180 0.15 12-1 Teflon
400De Teflon
400De 17 180 100 0.43

Weaving conditions (width and density control)

- Photos of developed products

As shown in FIG.

- Optical and SEM analysis of developed products

7 shows optical microscope and SEM analysis photographs of the product of the present invention.

3. Property measurement test

For the artificial blood vessels of the Teflon fabric according to the present invention, physical property measurement tests were carried out by the following principles, equipments, procedures and the like for each physical property item.

1) Dimensional inspection standard (inner diameter, outer diameter)

end. principle

A circular shaped artificial blood vessel is cut in the axial direction to expose the artificial blood vessel, and then the length of the artificial blood vessel is measured to measure the diameter of the artificial blood vessel (see FIG. 8).

I. equipment

Equipment used includes:

a) Devices meeting the requirements of ISO 5081

b) a tool for axially cutting the artificial blood vessel

c) vernier kellypur which can measure the circumference of cut artificial blood vessels

All. Sampling

The characteristics of artificial blood vessels should be able to demonstrate the representativeness of the available artificial blood vessels. Thus, at least three random samples are examined from three arbitrary batches.

la. Inspection procedure

The artificial blood vessels were cut in the axial direction and then flattened. The flattened specimens were placed. When the wrinkles were present, the wrinkles were removed and the artificial blood vessels were fixed using a suitable device so as not to move. The end of the fixed artificial vessel is measured with a vernier caliper.

hemp. Expression of result

After confirming the circumferential length (mm) of the measured artificial blood vessel, the radius is calculated and the diameter is displayed.

2) Water Permeability (Blood Leak Rate Measurement)

end. principle

This test measures the flow rate of water through a certain area of artificial blood vessels under constant water pressure.

I. Equipment (see Figure 9)

Equipment used includes:

a) Equipment to measure flow within 2% of full scale, with accuracy of ± 2% of full scale

b) Equipment capable of measuring water pressure up to 27 kPa (200 mmHg) with an accuracy of ± 0.3 kPa (± 2 mmHg)

c) Specimen holding equipment

- Equipped with holes with a diameter of 10 mm with ± 1% accuracy

- The shape of the hole is circular, acrylic holding equipment

- There shall be no bending or deformation in the test area which is six times the diameter of the specimen.

- There should be no leaks around the specimen.

d) Equipment that supplies water to the holding equipment at a pressure of 16 kPa (120 mmHg) and 27 kPa (200 mmHg)

All. Sampling

The characteristics of artificial blood vessels should be able to demonstrate the representativeness of the available artificial blood vessels. Thus, at least three random samples are examined from three random arrangements.

la. Inspection procedure

a) Cut the artificial blood vessel specimen to 20 mm x 20 mm.

b) Immerse the artificial blood vessels in clean, filtered water at room temperature prior to testing.

c) Fix the specimen to the holder and spread it enough to avoid warping.

d) Remove wrinkles if wrinkled.

e) Place 250 ml or more of distilled water in the place of distilled water.

f) Measure the pressure of the equipment under 16kPa (± 1kPa) and 27kPa (± 1kPa), respectively. At this time, it is assumed that 16 kPa = 120 mmHg and 27 kPa = 200 mmHg.

g) Measure the time required for 200ml of distilled water to pass through a 10mm diameter hole through artificial blood vessels under each pressure.

hemp. Expression of result

The water permeability is expressed in ml / cm2 / min. The water permeability is calculated and recorded from the following equation.

Water permeability = Q / A

Q: Flow through the sample (ml / min)

A: area (㎠) of the cut surface in the specimen holder (recording the area of the hole of the holder)

3) burst strength

The tear strength of artificial blood vessels is defined by diaphragm burst strength, probe burst strength, and pressurized burst strength, both of which are based on probe tear strength.

end. Principle (see Figure 10)

The artificial blood vessels to be inspected are fixed to the mouth using a flat annular clamp ring and traversed by a cylindrical probe with a hemispherical head until a rupture occurs. Continue to measure the applied load.

I. equipment

Equipment used includes:

a) Devices meeting the requirements of ISO 5081

b) Clamping holder shall be Ø10 mm in diameter and probe shall have Ø5 mm hemispherical end.

c) The clamping device fixes the artificial blood vessel so that the artificial blood vessel does not slip when the probe pushes the artificial blood vessel.

All. Sampling

The characteristics of artificial blood vessels should be able to demonstrate the representativeness of the available artificial blood vessels. Thus, at least three random samples are examined from three random arrangements.

la. Inspection procedure

The artificial blood vessels are cut along the longitudinal axis and then flattened. Place a flattened specimen at the entrance on the bottom of the instrument. If there are wrinkles, remove the wrinkles and tighten the clamp ring. Align the bottom with the probe and lower the probe until it touches the specimen. The probe was traversing the specimen until a rupture occurred. Record the diameter of the probe and the maximum load on each artificial vessel.

hemp. Expression of result

The diameter (mm) of the probe, the transverse velocity (mm / min), and the burst load (kilonewton) are displayed.

4. Measurement results and analysis of products

Evaluation items
(Main performance) unit % Of total items (%) World-class, owned / owned companies Domestic level before R & D Development
Target value Achievement level Assessment Methods Performance level Performance level Performance level Dimensional error rate
/ Diameter error rate Mm / 10 United States of America
Gore / 5 / 7 6/7 or less Technical Documentation
standard 400 De, 10 mm 10.0 / 7 10.71 / 7.1 90 De, 8 mm 8.0 / 7 7.96 / 0.5 90 De, 10 mm 10.0 / 7 9.79 / 2.1 Artificial blood vessel
Blood leakage rate Ml / cm2 / min 10 United States of America
Datascope / 300 350 350 or less Porosity
test
(KTL / KTR) 400 De, 10 mm Not measurable 90 De, 8 mm 0.5074 90 De, 10 mm 0.6934 Artificial blood vessel
Burst strength MPa 10 United States of America
Datascope / 4.5 4.0 4.0 or higher Punch ball
test (FITI) 400 De, 10 mm 5.56 90 De, 8 mm 4.61 90 De, 10 mm 4.40 * thickness ㎛ 250 or less 400 De, 10 mm 261 90 De, 8 mm 119 90 De, 10 mm 145

The physical property analysis result of the present invention product (woven teflon artificial blood vessel)

From Table 4, it is shown that the dimensional error rate of 400De deviates by 0.1%, but it is considered that it does not need to be much value because it is a result before changing the development direction to 90De.

The reason why the leakage rate of 400De is not measurable is considered to be that leakage occurs laterally depending on the degree of bending of the yarn during measurement.

However, considering the physical properties and the results described above,

A) Teflon 400De was weighed out, and it was too thick and tactile hard to be excluded.

B) According to the result of changing to Teflon 90De,

a. The target value of the bursting strength was set at 4 MPa, which showed a target value of 4 MPa or more at both diameters of 10 mm and 8 mm.

On the other hand, it showed better results than the rupture strength (1.28MPa) of PET 50De which is used in the past.

b. The target value of the thickness is 300 mu m or less, preferably 100 mu m to 150 mu m, all of which are achieved.

c. The leach rate results are below 350 ml / ㎠ / min. Furthermore, the test showed almost no leakage.

d. The aim of the error ratio of the diameter-related dimension was less than 7%.

5. Stretching test

On the other hand, in order to make products similar to the thickness and flexibility of existing PET 50De, it is necessary to consider measures to reduce the thickness of Teflon.

Thus, a stretching test was carried out in which the 90De monofilament and the 80De monofilament yarn produced according to the above-described method were stretched to lower the thickness.

Example

The Teflon yarn having the monofilament thickness of 80 De and 90 De was stretched at 1.06, 1.08, 1.10, and 1.12 on the drawing machine draw ratio (DR), and the fineness (d), the strength (cN · d) (%) Were measured. The reason why the middle stretching ratio is set to 1.12 is that the yarn breaks more than this range.

The filament thicknesses were divided into 80 De and 90 De and stretching tests were carried out. The results are shown in Tables 5 and 6, and Figs. 11 and 12, Figs. 13 and 14.

Drawing Ratio (DR) Theoretical fineness Fineness (d) Strength (cN · d) Shinto (%) Remarks Before stretching yarn 80De 82 5.29 7.81 1.06 77.35 79 6.67 4.94 1.08 75.92 78 5.83 4.43 1.10 74.54 76 5.96 4.44 1.12 73.21 77 6.45 4.68

Drawing Ratio (DR) Theoretical fineness Fineness (d) Strength (cN · d) Shinto (%) Remarks Before stretching yarn 90De 93 5.24 6.98 1.06 87.73 89 5.80 4.39 1.08 86.11 88 5.66 4.23 1.10 84.54 86 5.87 4.25 1.12 83.03 87 5.92 4.27

As shown in Tables 5 and 6, the Teflon filament yarn for artificial blood vessels according to the present invention showed relatively good strength (cN · d) and elongation (%) at a stretching ratio of 1.06 to 1.12, It was broken.

Specifically, the intensity of the 80De and 90De filaments in the stretching ratio range (i.e., 1.06 to 1.12) is in the range of 5.66 to 6.45 cN · d, and the elongation is 4.23 to 4.94%.

Particularly, when the filament thickness was 80 De and the stretching ratio was 1.12, the strength and elongation of the filament were 6.45 cN · d and 4.68%, respectively. When the filament had a thickness of 90 De and the stretching ratio was 1.12, the strength and elongation 5.92 cN · d and 4.27%, respectively.

Figs. 11 and 12 show electron micrographs of surface and cross-section of a Teflon yarn for artificial blood vessels (monofilament of 80 De) according to the present invention before and after a draw ratio of 1.12, I could not find it.

13 and 14 show electron micrographs of the surface and cross-section of the Teflon yarn for artificial blood vessels (monofilament of 90 De) according to the present invention before and after the stretching ratio of 1.12, I could not find it.

As described above, according to the present invention, a stent for a blood vessel to which a graft made of a Teflon fabric according to the present invention is applied has a high strength, that is, a high density, that has high breaking strength and thus has a limited water leakage rate. It is possible to prevent a leak accident.

In addition, as shown in the examples, the Teflon raw yarn used in the present invention is stretched within a stretching ratio of 1.12, and the strength and the like are suitable to be applied to artificial blood vessels, but they are thinned to reduce the thickness of artificial blood vessels and improve flexibility have.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the present invention as defined by the appended claims and their equivalents. .

10: Artificial blood vessels
20: Metal stent
100: stent for blood vessels

Claims (5)

A PTFE (Teflon) fabric for artificial blood vessels, which is a woven cylindrical body having a filament thickness of 80 De to 90 De, a fabric thickness of 100 占 퐉 to 150 占 퐉, and a blood leak rate of 10 ml / ,
Wherein the stretching ratio of the PTFE (mono-filament) filament yarn for use in the artificial blood vessel Teflon fabric is from 1.06 to 1.12,
The strength of the PTFE (mono-filament) yarn in the stretching ratio range is 5.66 to 6.67 cN · d,
Wherein the elongation of the PTFE (monofilament) monofilament yarn is in the range of 4.23 to 4.94% in the range of the stretching ratio.
delete delete The method according to claim 1,
Wherein the filament has a thickness of 80 De and a draw ratio of 1.12, the strength and elongation of the filament are 6.45 cN · d and 4.68%, respectively.
The method according to claim 1,
Wherein the filament has a thickness of 90 De and a draw ratio of 1.12, the strength and elongation of the filament are 5.92 cN 占 and 4.27%, respectively.

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