KR19990024880A - Manufacturing method of nonabsorbable monofilament suture - Google Patents

Abstract

The present invention relates to a method for manufacturing a nonabsorbable monofilament suture, and more particularly, after the instantaneous heat treatment of the suture polymer to a high temperature above the melting point in the stretching process in the preparation of the nonabsorbable monofilament suture is characterized in that the suture surface is solvent treated. It relates to a method for producing a non-absorbent monofilament suture excellent in flexibility.

The nonabsorbable monofilament sutures prepared by heat treating the suture at a temperature above the melting point of the polymer to increase the amorphous region of the fiber surface and then solvent treatment have excellent flexibility.

Description

Manufacturing method of nonabsorbable monofilament suture

The present invention relates to a method for manufacturing a nonabsorbable monofilament suture, and more particularly, after the instantaneous heat treatment of the suture polymer to a high temperature above the melting point in the stretching process in the preparation of the nonabsorbable monofilament suture is characterized in that the suture surface is solvent treated. It relates to a method for producing a non-absorbent monofilament suture excellent in flexibility.

Sutures used as surgical sutures can be classified into natural sutures and synthetic sutures, depending on the raw materials.The sutures are sutured according to their absorption in vivo, and then absorbed sutures and wounds are naturally decomposed and absorbed into the body after a certain period of time. It is divided into nonabsorbable sutures that do not degrade even after sutures.

In addition, the suture may be divided into a monofilament suture and a multifilament suture depending on the structure. Monofilament sutures are manufactured from hundreds to thousands of deniers, attached to needles, sterilized and packaged, and multifilament sutures spin and stretch multifilaments made up of tens of strands of monofilaments of 1 to 5 deniers in thickness. It is then woven into dozens of strands.

Since the multifilament suture goes through the braiding process, the production rate is low due to the low production speed, and the bacterial infectivity due to the capillary phenomenon is higher than that of the monofilament suture. In order to make up for the shortcomings of such multifilament sutures, development of monofilament sutures has been conducted.

U. S. Patent No. 3,630, 205 describes a method for producing monofilament sutures using polypropylene, and U. S. Patent No. 4,052, 988 describes a method for producing monofilament sutures using paradioxanone.

In general, in order to use as a suture, the strength should be large, have an appropriate elongation of about 20 to 60%, and the elastic modulus should be small in terms of improving the flexibility of the suture. However, in the case of monofilament sutures, such as polypropylene, which are conventionally used, the strength and elongation are excellent, but the knot characteristics such as knot fastening properties are poor due to poor flexibility. Thus, there has been a demand for improved flexibility in monofilament sutures.

According to U.S. Patent No. 3,630,205, although the tensile strength is somewhat lowered, the flexibility is improved when the draw ratio of the monofilament suture is stretched to about 6.6 and relaxed about 76 to 91% of the stretched length.

In the present invention, in order to solve the problems of the prior art as described above to produce a monofilament suture with excellent flexibility when the suture is stretched in the manufacturing process of the monofilament suture, the polymer is passed through a heater at a temperature above the melting point to form an amorphous region on the polymer surface side. After increasing, it was again treated with a suitable solvent to promote the penetration of the solvent into the amorphous region of the polymer surface to obtain a non-absorbent monofilament suture with improved flexibility.

An object of the present invention is to provide a non-absorbent monofilament suture excellent in flexibility and a method of manufacturing the same.

The present invention heats the suture discharged from the radiator and passed through the first stretched roller portion to a temperature above the melting point of the suture polymer by a heater, and then passes through the second stretched roller portion to prepare a monofilament suture, and then prepares the monofilament suture It is a method for producing a non-absorbent monofilament suture excellent in flexibility, characterized in that the surface treatment with a solvent soluble to the polymer.

Hereinafter, the present invention will be described in more detail.

In the present invention, the diameter of the suture is adjusted by adjusting the discharge amount of the polymer so that the suture polymer meets the desired suture specification in a conventional spinning machine equipped with an extruder or the like. The suture discharged from the radiator is cooled by the cooling water while passing through the first guide roller and then transferred to the first stretching roller part by another guide roller. The draw rollers each rotate at the same speed. The suture that has passed through the first drawing roller portion is drawn by a second drawing roller portion which is heat-treated while passing through the heater and then rotates at a higher speed. The suture is stretched by the speed difference between the first stretched roller portion and the second stretched roller portion installed before and after the heater, and adjusts the draw ratio to about 3 to 7 depending on the properties of the suture to be obtained.

The temperature of the heater for instantaneously heating the suture passed through the first draw roller portion may be adjusted to a temperature depending on the polymer used, preferably 20 to 75 ° C. higher than the melting point of the polymer used. In the spinning and drawing process, the suture is fast moving and the suture is exposed to heat, so the high temperature is required for heating in a short time.

As described above, according to the present invention, the fibers are stretched by applying heat above the melting point for a short time, thereby forming amorphous regions on the fiber surface without affecting the inside of the fibers. Through this process, monofilament sutures in which amorphous regions are formed on the fiber surface can further increase the flexibility of the sutures by solvent treatment.

After the heat treatment process, the suture is wound up and treated with a solvent capable of dissolving the suture polymer such as formic acid, thereby further improving the flexibility of the monofilament suture. That is, the monofilament fibers with amorphous regions developed on the surface are wound on a cylindrical drum to treat the surface of the fibers with a suitable solvent. The fibers heat-treated at a temperature above the melting point have an increased amorphous region, so the solvent is very easy when the solvent is treated. It may be penetrated into the fiber to improve the flexibility of the monofilament suture.

Polymers usable in the present invention include nylon, polyolefins (polypropylene, polyethylene, etc.), polyurethanes, polycarbonates, polyimides, vinyl polymers, and the like.

Examples of the solvent for treating the surface of the suture include ethyl acetate, acetone, methyl alcohol, ethyl chloride, acetic anhydride, methylene chloride, ethyl alcohol, benzene, xylene, tetrahydrofuran, and formic acid.

Solvent treated monofilament suture after the heat treatment in the stretching process according to the present invention appears to be significantly less elastic modulus provided as a measure of flexibility compared to monofilament suture subjected to heat treatment only or monofilament suture subjected to solvent treatment only excellent flexibility This has been proven.

Hereinafter, the present invention will be described in detail by way of examples.

Example 1

A monofilament suture of USP 5/0 was prepared by spinning at 275 ° C using nylon 6 (m.p. 215 ° C) having a sulfuric acid relative viscosity of 2.5. The temperature of the cooling water was 18 ° C., and the stretching roller speed was 200 m / min and 860 m / min, respectively, so that the draw ratio was 4.3. The temperature of the heater was 275 ° C, and the wound monofilament fiber was treated with formic acid as a solvent at 100 ° C for 10 minutes.

The monofilament suture before solvent treatment had a tensile strength of 6.21 g / d, a tensile elongation of 25.9%, a knot strength of 4.32 g / d, and an initial modulus of elasticity of 35 g / d. The tensile strength, tensile elongation and knot strength after treatment with formic acid solvent were almost unchanged and the initial elastic modulus was 20 g / d.

Example 2

A monofilament suture of USP standard 3/0 was prepared by spinning at 285 ° C using nylon 6 (m.p. 215 ° C) having a sulfuric acid relative viscosity of 2.5. The temperature of the cooling water was 22 ° C., and the stretching rollers were 180 m / min and 720 m / min, respectively. The temperature of the heater was 280 ° C, and the wound monofilament fiber was treated with formic acid as a solvent at 100 ° C for 15 minutes.

The tensile strength of the prepared monofilament suture was 3.67 g / d, tensile elongation was 40.7%, knot strength was 2.98 g / d, initial elastic modulus was 30 g / d before the solvent treatment, and 17 g / d after the treatment. .

Example 3

Monopropylene filament suture of USP standard 4/0 was prepared by spinning at 210 ° C using polypropylene having a melt index of 10 (m.p. 170 ° C). The temperature of the cooling water was 22 ° C., and the stretching rollers had speeds of 150 m / min and 1050 m / min, respectively, so that the draw ratio was 7. The temperature of the heater was 240 ° C., and the wound monofilament fiber was treated with xylene as a solvent at 130 ° C. for 20 minutes.

The tensile strength of the prepared monofilament sutures was 5.13 g / d, 27.5% tensile elongation, 2.68 g / d knot strength, initial elastic modulus was 60 g / d before solvent treatment, and 22 g / d after treatment. .

Example 4

The polypropylene (m.p. 170 ℃) with a melt index of 12 was spun at 210 ℃ to prepare a monofilament suture of USP standard 3/0. The temperature of the cooling water was 16 ° C., and the stretching rollers had speeds of 150 m / min and 700 m / min, respectively, so that the draw ratio was 4.7. The temperature of the heater was 240 degreeC, and the wound monofilament fiber was processed for 15 minutes at 140 degreeC using xylene as a solvent.

The prepared monofilament suture had a tensile strength of 5.57 g / d, an elongation of 28.5%, a knot strength of 2.57 g / d, an initial modulus of elasticity of 50 g / d before the solvent treatment, and 23 g / d after the treatment. .

Comparative Example 1

It was prepared by spinning at 275 ° C using nylon 6 (m.p. 215 ° C) having a sulfuric acid relative viscosity of 2.5 to multistage stretch of monofilament sutures of USP 5/0. The temperature of the cooling water was 18 ° C., the speed of the cooling roller was 200 m / min, the speed of the first roller was 210 m / min, the temperature was 60 ° C., and the speed of the second roller was 830 m / min. The speed | rate was 870 m / min, the temperature was 130 degreeC, and the speed of the 4th roller was 860 m / min, and the draw ratio was 4.3.

The wound monofilament fibers were treated for 10 minutes at 100 ° C. using formic acid as a solvent. Tensile strength of the prepared monofilament suture was 6.30g / d, tensile elongation was 23.4%, the initial modulus was 29g / d.

Comparative Example 2

The polypropylene (m.p. 170 ℃) having a melt index of 12 was spun at 210 ℃ to prepare a multi-stage stretch of monofilament suture of USP standard 3/0. The temperature of the cooling water was 16 ° C, the speed of the cooling roller was 150m / min, the speed of the first roller was 160m / min, the temperature was 65 ° C, the speed of the second roller was 600m / min, the temperature was 90 ° C, and the third roller. The speed of the 710m / min temperature was 95 ℃, the speed of the fourth roller was 700m / min temperature was 125 ℃ to have a draw ratio of 4.7.

The wound monofilament fibers were treated for 15 minutes at 140 ° C. using xylene as a solvent. Tensile strength of the prepared monofilament suture was 5.81g / d, tensile elongation was 25.3%, the initial modulus was 38g / d.

According to the method of the present invention, the monofilament suture produced by heat-treating the suture at a temperature above the melting point of the polymer to increase the amorphous region of the fiber surface and then solvent treatment has excellent flexibility.

The suture obtained by the present invention is flexible and has excellent knot stability and the like, and can be used not only as a suture but also as a soft tissue patch, a surgical mesh, a thin film dressing, a surgical felt, and the like.

Claims (2)

The suture discharged from the radiator and passed through the first stretched roller portion is heat-treated by a heater to a temperature higher than the melting point of the suture polymer, and then passed through the second stretched roller portion to prepare a monofilament suture, and then the monofilament suture is manufactured to the polymer. A method for producing a highly flexible non-absorbent monofilament suture, characterized in that the surface treatment with a solvent soluble. The method of claim 1, wherein the solvent is selected from the group consisting of ethyl acetate, acetone, methyl alcohol, ethyl chloride, acetic anhydride, methylene chloride, ethyl alcohol, benzene, xylene, tetrahydrofuran, and formic acid A method for producing a flexible nonabsorbable monofilament suture.