HU184083B - Method for producing elastic catgut - Google Patents

Abstract

The present invention relates to a method for producing elastomeric surgical suture material. In the process according to the invention, a single-strand flow rate of 2-9%, viscoelastic elongation of 1030%, Young modulus of 2,100-14,000 kg / cm2, tensile strength of at least 2,800 kg / cm2, and a kneading strength of at least 2,100 kg / cm2 - produce elastomeric surgical suture material by extruding a suitable copolymer / ester polymer, the extruded product is suddenly cooled and provided to a certain extent. -1-

Description

The present invention relates to a process for the production of elastomeric surgical sutures. More particularly, the present invention relates to the manufacture of a soft, elastomeric surgical suture material which may be well handled and knotted comprising copolyether / ester segments or other elastomeric polymers.

The process of the present invention provides an elastomeric surgical suture comprising a single filament having a tensile strength of ^{2 to} 9%, a viscoelastic tensile strength of 10 to 30%, a Young modulus of 2,100 to 14,000 kg / cm ² , and a tensile strength of at least 2,800 kg / cm ² ; a knot strength of at least 2,100 kg / cm ² - a compound of copolyether / ester segments having repeating long chain ether / ester units and lower ester units attached thereto by ester linkages and having the general formula (I) wherein G is a divalent group, remaining after removal of a molecular weight polyethylene / C between 350 to 6000 _{2 to 10} alkylene oxide) glycol with terminal hydroxyl groups, R is a divalent group which, after removal of the carboxyl groups remains less than 300 molecular weight aromatic dicarboxylic acid, D is a divalent groups a residue remaining in an alkyl diol having a molecular weight of less than about 250 after removal of the hydroxyl groups, a and b being an integer such that 50% to 90% by weight of the lower units represented by a in the total copolymer, n is degree of polymerization such that the value is such that it results in a fiber-forming polymer.

The process according to the invention is carried out by removing all impurities in the copolyether / ester by drying, then immediately cooling the extruded copolyether / ester with water and stretching the chilled copolyether / ester 5 to 10 times.

At present, many natural or synthetic materials are used as surgical sutures. They may be composed of a single filament, these being single-filament sutures, or of multiple filaments, for example, in a knit or filament form. Natural fibers such as silk, cotton, linen, etc. of course, they are not suitable for the production of a single-fiber suture, so they are generally used to make a multi-thread suture.

Synthetic materials, which can be extruded into endless filaments, can be used to make single-thread sutures. The most common single-thread synthetic sutures are polyethylene terephthalate, polypropylene, polyethylene and nylon. Surgeons prefer these single-thread sutures because they are uniform and do not absorb body fluids.

Each of the known synthetic single-thread surgical sutures has the more or less inherent disadvantage of their rigidity. In addition to being difficult to handle and apply, the stiffness of the suture has a detrimental effect on the formation and durability of the knot. Because of the rigidity of known single-thread surgical sutures, larger sutures are interwoven or other multi-filament shapes are formed which are more easily handled.

Known single-thread sutures also have low elasticity. Of the synthetic materials used for surgical purposes, the most elastic is nylon with a tensile elongation of about 1.7% and a viscoelastic elongation of about 8.5%. Because of its rigidity, knitting is harder than known single-thread sutures and the knot's safety - durability - is unsatisfactory. In addition, due to inflexibility, the suture does not expand properly when the freshly sutured wound is swollen, resulting in more than desirable stretching of the injured tissue, and even some tissue rupture, incision, or even death.

The difficulties associated with the use of inflexible surgical sutures in certain areas have already been pointed out in U.S. Patent No. 3,454,011. U.S. Pat. No. 4,123,195, and it is proposed that the surgical suture be made from Spandex polyurethane. However, this known suture material has too elastic rubber-like properties and has not worked in the medical field.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel, soft, flexible single-thread surgical suture. It is a further object of the present invention to provide a single-thread suture material having a degree of elasticity appropriate to the varying state of the wound. It is a further object of the present invention to provide a new surgical suture having a diameter of 0.01 to 1.0 mm that is non-absorbent and has good physical properties.

The single-thread surgical suture of the present invention has the following physical properties:

tensile elongation viscoelastic elongation Young modulus tensile strength knot strength

2-9%

10-30%,

30,000-200,000 psi 2,100-14,000 kg / cm ² at least 40,000 psi

2,800 kg / cm ² at least 30,000 psi

2,100 kg / cm ²

A suture material having the above characteristics may be prepared by extruding a melt of certain elastomeric polymers, such as copolyether / ester polymers, and then drawing the resulting web to a fiber having the desired properties. It has now been found that the starting material for making the suture material of the present invention is a copolyether / ester polymer marketed under the name HYTREL ( ^R ) (manufactured by EI du Pont de Nemours and Co.).

The monofilament sutures of the present invention having the above physical properties are particularly suitable for suturing wounds that may subsequently become swollen or reversed. The low value Young modulus and the high flow elasticity combine to provide a suture material with a small amount of effective, high controlled elasticity under force. Thus, the suture material of the present invention is capable of adequate elongation when the wound swells. The relatively high viscoelastic elongation and high tensile strength of the suture allow

-2184 083 elongates when knotted, resulting in better knot resistance and a safer, more durable knot. The geometry of the formed knot can be predetermined whether it is a change in the knotting method or the tension applied to the knot.

Figure 1 illustrates a stretch-deformation relationship typical of a surgical suture of the present invention.

Figure 2 shows a strain-deformation curve of the suture material of the present invention compared to other known single-thread sutures.

The characteristic physical properties of the single-thread surgical suture of the present invention are determined by measuring methods known per se. In Fig. 1, which is a typical tension / strain or load / elongation diagram of the suture material of the present invention, the flow elongation (E _y ) is the point at which the permanent deformation of the suture material begins. As long as the fiber is not stretched beyond the E _y point, the elastic bounce is substantially complete. In the suturing material of the invention, the E _y point is between 2% and 9%.

The Young modulus is the directional tangent of the initial section of the strain / strain curve starting from the origin. In Fig. 1, the line a is the tangent to the curve starting from the origin and corresponds to the Young modulus tg θ. It can be seen that Young's modulus is the measure of elongation resistance at the initial "elastic" section of the curve. The Young's modulus of the suture material of the present invention is significant but relatively low, between 2100 and 1400 kg / cm ² , preferably between 3500 and 10 500 kg / cm ² .

If the Young modulus is above, a sufficient tensile stress is created in the suture material as its elongation approaches the melting point. If the Young modulus is less than the above, the suture will easily stretch at very low tension and reach the melting point; Thus, the advantages of high flow elongation are lost. Conversely, if the Young modulus is greater than the above range, the fiber becomes stiffer and loses its softness and good handling.

The section of the stress / strain curve shown in Figure 1 between the points E _y and E _{y is} a viscoelastic region in which the elongation and permanent deformation of the suture material is significant, even if the tensile stress increases only slightly. The suture material of the present invention has a viscoelastic elongation (E _y ) of from about 10% to about 30%. This property of the sewing material allows it to be tensioned during knot bonding to obtain a secure knot.

In cases where the sutures _y exceeds this point, the load is growing rapidly, as illustrated in Figure 1. This rapid increase in load is detected by the experienced surgeon and is signaled when E _y point and maximum node security are reached.

Preferably, E _y is at least 2.5 times its E value. In this case, a broad viscoelastic range is available to the surgeon during the node.

As shown in Figure 1, the load from the origin to the elongation E _{y is} relatively small compared to the burst load value (Sb). Preferably, the tensile load is at least 2,800 kg / cm ² and the Sv load corresponding to the viscoelastic elongation is less than one third of the tensile load. As a result, the suture material can be easily knotted using a relatively small amount of force without risking tearing the suture material. The suture material preferably has a knot strength of at least 2,100 kg / cm ² .

The tensile elongation (Eb) of the suture material of the present invention is generally 30 to 100%. Although this property is not critical to the usefulness of the suture material, since the stretch applied during use generally does not exceed E _y , it is preferred that Eb be at least one and a half times its E value. This reduces the possibility of inadvertently stretching and tearing the sewing material during knotting.

The unique mechanical properties of the suture material of the present invention are readily apparent from Figure 2, where the suture material of the present invention is compared with known nylon and polypropylene sutures. The physical properties of these three sutures are shown in Table I. Known suture materials have a Young's modulus that is significantly higher than that of the suture material of the present invention and thus exhibit stiffness. In addition, none of the known sutures exhibits a noticeable E _y value, i.e., an elongated viscoelastic range, which characterizes the suture material of the present invention and imparts the above favorable properties.

The mechanical properties of the suture material of the present invention, which are reflected by the relative values of E _y and E combined with the low Young modulus and high tensile strength, are unique in the field of surgical sutures and favor the single suture sutures of the present invention.

spreadsheet

Mechanical property- pany suture material Polipro- used in lieu of nylon Invention of Diameter, mm 0.32 0.33 0.33 Tensile strength, psi 58.900 75 200 64 700 (kg / cm ² ) (4100) (5300) (4500) Elongation at break,% 32.2 40.1 39.5 viscoelastic elongation (Ev)% 9.0 8.5 14.8 Flow elongation (Ey)% 1.1 1.7 2.2 Tension at Ey (Sy), psi 5100 3600 2500 (kg / cm ² ) (360) (250) (180) Tension at Ev (Sv), psi 25 700 13,200 9200 (kg / cm ² ) (1800) (930) (650)

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8

Mechanical Sewing Material Proprietary Polypropylene Nylon Invention Pillow

Young module, psi 425,000 221,000 112,000 (kg / cm ² ) (20,900) (15,500) (7,900)

Sewing materials having mechanical properties according to the invention are disclosed in U.S. Patent No. 3,023,192. can be prepared from materials comprising copolyether / ester segments as described in U.S. Pat. From column 2 of column 2 of the cited anteriority the following is stated:

"The copolyether / esters of the present invention are prepared by reacting one or more dicarboxylic acids or ester-forming derivatives thereof with one or more difunctional polyethers of the formula H0 (R0) _p H, wherein R is one or more divalent organic groups, have a molecular weight between 350-6000 glycol, and reacting one or more dihidroxivegyülettel which diszfenol or an H0 _(CH2) small aliphatic formula _q 0H glycol may, where q is 2-10, with the proviso that the polyester is substantially all its repeating unit contains at least one aromatic ring. The resulting ester is then polymerized. "

Other similar segment-based thermoplastic copolymers are prepared according to U.S. Patent Nos. 3,651,014, 3,763,109, 3,766,146 and 3,784,520. U.S. Pat.

According to the above anteriorities, known segmented thermoplastic copolymers can be molded into film, molded into various shapes, or extruded into fibers. However, products made by anteriority have physical properties that are undesirable for surgical sutures. For example, fibers made in the known manner are rubbery and have a high degree of elasticity, as indicated by elongation at break greater than 500%. However, their tensile strength is very low, even below 608 kg / cm ² . Therefore, if the fibers described in the above anteriorities are made of copolyether / ester, the resulting products do not have the mechanical properties of the sutures of the present invention and are obviously completely unsuitable for surgical sutures.

In the process of the present invention, the corresponding copolyether / ester is extruded, then cooled and then stretched. This process provides fibers having mechanical properties within the limits particularly favorable for surgical sutures.

The segmented copolyether / esters used in the present invention consist of a number of repeating long-chain ether / ester units and lower-ester units, and the two types of units are linked together via ester linkages. This structure is illustrated by formula (I).

The polymeric long chain ether / ester units can be presented by the general formula (II) wherein G is a divalent radical remaining after removal of a molecular weight polyethylene / C between 350-6000 ₂ _j ₀ alkylene oxide) glycol with terminal hydroxy groups. R is a divalent residue remaining after removal of carboxyl groups from an aromatic dicarboxylic acid having a molecular weight of less than about 300.

The lower ester moiety is represented by the general formula (III) wherein D is a divalent residue remaining after removal of hydroxyl groups from an alkyl diol having a molecular weight of less than about 250, R is as defined above.

In the above formula (I), a is an integer such that the lower copolymer segment comprises 50 to 90% by weight of the total copolymer; b is an integer such that the long-chain copolymer segment represents 10 to 50% by weight of the total copolymer; n is the degree of polymerization that is such that it results in a fiber-forming copolymer.

When the copolyether / esters of formula (I) are extruded during melting, quenched and stretched, fibers having the physical properties required for surgical sutures and defined above are obtained. The polymer to be extruded is dried at about 93 ° C to 104 ° C in a spinning air oven and / or vacuum to remove traces of moisture and other volatiles. The polymer is then melt extruded and quenched with water according to molten fiber drawing techniques commonly used in synthetic fibers. Finally, the fiber is stretched at least five times, but usually 7-9 times, to provide molecular orientation.

The preparation of surgical suture fibers from copolyethers / esters in accordance with the present invention is illustrated in detail by the following examples. The polymers used in the examples were made from 1,4-butanediol, di40 methyl phthalate, and polytetramethylene ether glycol (about 1000 molecular weight), available from EI du Pont de Nemours and Co. under the name HYTRE1 / ^R. The polymer contains intrapolymerized butylene phthalate hard segments (lower ester units) and po45 litetramethylene ether terephthalate soft segments (long ester units). Its general chemical structure is described in the Journal of Elastomers and Plastics, 2, 416438 (1977), wherein a and b are as defined above, x is an integer representing the molecular weight of the glycol ether component (x = 14 if the molecular weight is about 1,000).

In the following examples, the physical properties of each of the single-thread sutures were assayed using an Instron tear machine under the following measurement conditions:

crosshead speed (XH): 2.1 m / s paper speed (CS): 4.2 m / s sample length (GL): 126.7 mm scale load (SL): 35 g / mm

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Referring to Figure 1, Young's modulus is calculated from the directional tangent of the initial linear elastic section of the strain / strain curve using the following formula:

tg 0 x GL x CS x SL

Young modulus (psi) =

XHxXS where 0 is the angle XS in Fig. 1 is the cross-section of the fiber, in ² SL XH, CS and GL are as defined above.

The flow stress (Sy) is the load at the intersection of lines a and b. Line a and b are drawn tangentially to the initial elastic section and the viscoelastic section of the curve shown in Figure 1. The elongation at flow (Ey) is the elongation at Sy and can be read directly from the stress / strain curve.

The viscoelastic stress (Sv) is the load at the intersection of line b and line c tangentially drawn on the curve of Figure 1. The viscoelastic elongation (Ev) is the elongation at Sv and can be read directly from the curve.

Tensile elongation (Eb) and tensile strength (Sb) can be read directly from the strain-deformation curve as shown in Figure 1.

Example I Started from a sample of a copolyether / ester of formula IV having about 40% by weight of soft segment, about 51% of terephthaloyl, 16% of polytetramethylene ether glycol and 33% of 1,4-butanediol based unit contain. The sample was dried for 4 hours at 93 ° C in an air circulation oven and then further dried without heating for 16 hours in a 100 micron vacuum. The dry polymer was placed in a 2.54 cm horizontal extruder and extruded at 193 using a J / 50/1 die.

The extruded product is cooled to ambient temperature in water and stretched to a 2-0 size single-strand suture using an 8.8 fold stretch at 277 ° C at 2.5 m / s. The physical properties of the fiber obtained are shown in Table II. Table.

II. example

Start from a sample of a copolyether / ester of formula IV having approximately 23% by weight of soft segment, about 45% of terephthaloyl unit, 4% of orthophthaloyl unit, 20% of polyetherethylene ether glycol based unit and 31% of 1,4-butanediol -based unit. The sample is dried as described in Example I and extruded at 204 ° C. The extruded product is cooled with water and stretched to a size 2-0 using a 7.5x stretch at 232 ° C and 2.1 m / s. . The physical properties of the fiber obtained are shown in Table II. is shown in Table.

III. example

We start from a sample of the copolyether / ester of formula IV containing approximately 18% by weight of soft segment, about 41% of terephthaloyl, 35% of polytetramethylene ether glycol based and 24% of 1,4-butanediol based. The sample was dried as described in Example I and extruded at 207 ° C. The product obtained by extrusion was cooled suddenly and converted to 2-0 filaments by stretching 6.5 times at 293 ° C and 0.4 m / s. The physical properties of the single-thread suture material thus obtained are shown in Table II. is shown in Table. It is noted that the Young's modulus of the product was higher than the desired upper limit for the suture materials of the present invention.

ARC. example

The amount of the copolyether / ester used in Example I was 3 parts by weight and the amount of the copolyether / ester used in Example III. 2 parts by weight of the copolyether / ester of Example 1 are mixed in a dry state. This results in a polymer having a total of 30.2% soft segment. The blended material is dried in a vacuum oven for 2 hours at 133-266 N / m ² without heating and then for 3 hours at 5 ° C and 133-266 N / m ² .

The dried mixture was melt-blended to facilitate mixing in a 19 mm Brabender extruder with 635 mm drum and 20/1 screw and then extruded at 221 ° C through a 4 mm die in a horizontal machine. The product obtained by extrusion is rapidly cooled with water to ambient temperature, granulated and dried again as described above, and then extruded into a single-thread suture at 204 ° C. Finally, a stretch of 7.9 times was applied at 238 ° C and 2.2 m / s. The physical properties of the fiber obtained are shown in Table II. Table.

Example V

The amount of the copolyether / ester used in Example I was 3.5 parts by weight, and the amount of the copolyether / ester used in Example III. The copolyether / ester 1.5 parts by weight used in Example 1b is blended in the dry state so that the mixture contains a total of 33.4% soft segment. The mixture was prepared as described in Table IV. . A 7.5x stretch is applied at 252 ° C and 2 m / s. The physical properties of the resulting 2-0 single-stranded suture material are a

II. is shown in Table.

VI. example

The IV. Example I, II. and III. using various mixtures of copolyether / ester polymers used in Example 1A. The composition of the polymers and the physical properties of the fibers obtained a

III. is shown in Table.

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VII. example

III. The copolymer / ester sample used in Example I containing% by weight of soft segments was dried and extruded as in Example I. Using 0.5 mm spinneret 5-0 suture size, 1.0 mm ³ size 0 spinnerette is obtained fibers. The IV. Table II compares the stretching conditions and physical properties of the resulting sutures with a 2-0 suture of the same composition as in Example I. 10

Π. spreadsheet

Example number 15 I II. III. Size of sewing material 2-0 2-0 2-0 Diameter, mils 11.1 13.1 123 (Mm) (0.28) (0.33) (0.31) 20 Knotted solid- psi 37.200 39 700 44.900 (kg / cm ² ) (2600) (2780) (3140) Tensile strength, psi 64,100 71 300 72 300 25 (kg / cm ² ) (4490) (4990) (5060) Elongation at break,% 31.8 27.8 18.3 viscoelastic elongation,% 18.6 13.3 7.25 Flow elongation,% 3.2 2.9 2.6 30 Young's modulus, psi 50,000 172.000 320,000 (kg / cm ² ) (3500) (12,000) (22,400) 35 Example number ARC. V Size of sewing material 2-0 2-0 40 Diameter, mils 13.2 13.2 (Mm) (0.34) (0.34) Node strength, psi 40 100 41,000 (kg / cm ² ) (2800) (2870) Tensile strength, psi 65.500 60,500 45 (kg / cm ² ) (4580) (4200) Elongation at break,% 25.2 31.4 Viscoelastic elongation,% 10.35 11.6 Flow elongation,% 43 4.7 50 Young's modulus, psi 140,000 120,000 (kg / cm ² ) (9800) (8400)

Composition of polymer Mix soft nail- mens s% Young's modulus psi (kg / cm ² ) Tear, elongation, eb, % Soft segments of components, s% com- impregnation solution weight- The proportion 40/23 65/35 34.05 84,000 (5850) 34.8 40/18 75/25 34.50 107.000 (7470) 33.4 40/23 50/50 31.50 105,000 (7320) 33.7 40/18 70/30 33.40 120,000 (8390) 31.4 40/18 65/35 32.30 134,000 (9400) 27.5 40/18 60/40 31,20 140,000 (9790) 26.5 40/18 55/45 30,10 170,000 (11,920) 24.5 40/18/23 30/30/40 26.60 173,000 (12,080) 18.9 40/23/18 30/30/40 26,10 201,000 (14,060) 22.4

Composition of polymer viscosity elastic elongation, % flow elongation, ey, % Soft segments of components, s% components of sek weight- The proportion 40/23 65/35 14.3 9.2 40/18 75/25 13.3 3.2 40/23 50/50 14.7 1.9 40/18 70/30 11.6 4.7 40/18 65/35 12.1 4.6 40/18 60/40 10.2 4.8 40/18 55/45 10.8 2.6 40/18/23 30/30/40 10.3 3.5 40/23/18 30/30/40 10.3 2.8

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ARC. Spreadsheet

Sewing Material Size 5-0 2-0 0

Extension 7,5x 8,8x 7.3x ⁺ Strain temperature, ° C 171 277 188 Stretch speed m / sec 1.0 2.5 0.6 Diameter, mils (mm) 7.08 0.18 11.10 0.28 14.03 0.35 Knot strength, psi (kg / cm ² ) 48.600 3400 37.200 2600 34.200 2400 Tensile strength, psi (kg / cm ² ) 67,500 4700 64,100 4400 68 600 4800 Elongation at break,% 43.5 31.8 36.7 Viscoelastic elongation,% 10.8 18.6 17.6 Flow elongation,% 3.0 3.2 6.3 Young modulus, psi (kg / cm ² ) 49,000 (3400) 50,000 (3500) 51,000 (3600)

⁺ Stretching was done in two stages.

VIII. example

II. The single-strand sutures made from copolyether / ester containing 23% by weight of the soft segment used in Example 1A were sterilized with cobalt-60 isotope radiation and ethylene oxide as is conventionally used to sterilize surgical sutures. The physical properties of the sutures were only slightly affected by ethylene oxide treatment and even less by radiation from the cobalt-60 isotope, as shown in Table V.

Table V.

suture material properties Non-sterile control Sterilized Co. ⁶⁰ ethylene oxide Diameter, mils 12.5 12.6 13.2 mm 0.31 0.32 0.33 Knot strength, psi 35 300 33.400 29,900 kg / cm ² 2500 2300 2100

14 Table V \ t (continued) suture material properties Non-sterile control Sterilized £ _θ 60 Ethylene oxide Tensile strength, psi kg / cm ² 70 300 4900 70,000 4900 67,700 4800 Elongation at break,% 28.2 31.6 45.2 Viscoelastic elongation,% 13.2 15.0 23.5 Flow elongation,% 2.9 2.3 2.2 Ycung modulus, psi (kg / cm ² ) 185,000 (13,000) 165,000 (11,600) 138,000 (9600)

The essential physical properties of the copolyether / ester suture materials correspond to changes in the polymer composition and production conditions. For example, the value of viscoelastic elongation and flow elongation increases as the proportion of soft segments in the polymer increases, and conversely, the Young's modulus decreases with the increase in the proportion of soft segments. The tensile elongation may be reduced and the tensile strength may be increased if a greater amount of elongation is used in the manufacture of the suture material. By adjusting the composition and manufacturing parameters, sutures with specific mechanical properties can be obtained.

Although the previous examples described the preparation of copolyether / ester monofilament sutures, this was done for the sake of simplicity as it is simpler to describe a single polymeric system and to describe the effect of different polymer compositions and filament conditions on single-filament sutures. The copolyether / ester polymers can also be spun or otherwise made into spun yarns, and the single yarn and cord used to make surgical fabrics. Looping or weaving can be used to form prostheses, such as venous or arterial replacements.

In addition, a variety of elastomeric filaments having the properties of the invention can be prepared from other polymeric systems. Examples include polyurethane or silicone elastomers and polyether copolymers of urethane or silicone elastomers.

The elastomeric fibers of the present invention may be blended with each other, other elastomeric or non-elastomeric fibers, and absorbent or non-absorbent fibers to obtain yarns or fabrics having specific properties. These products are all within the scope of the invention.

Claims (7)

Patent claims 1. A method of elastomeric surgical suture comprising a single filament having a tensile strength of ^{2 to} 9%, a viscoelastic tensile strength of 10 to 30%, a Young modulus of 2,100 to 1,4,000 kg / cm ² , a tensile strength of 2,800 kg / cm ² and a knot strength of 2,100 kg. kg / cm ² - from an elastomer of formula (I) having repeating long-chain ether / ester units and lower-ester units attached via ester linkages, wherein G is a divalent group having a molecular weight of 350-6,000 R ₂ is a divalent group remaining after removal of a carboxyl group from an aromatic dicarboxylic acid having a molecular weight of less than 300, D is a divalent group having a molecular weight of less than about 250 alkyl the diol remains after removal of the hydroxyl groups, a and b being an integer such that 50% to 90% by weight of the lower units represented by a of the total copolymer, n being a degree of polymerization such as to produce a fiber-forming polymer characterized in that all the impurities in the elastomer are removed by drying and immediately afterwards, the melt of the elastomer is extruded, the resulting fibers are quenched with water and stretched 5 to 10 times the cooled fibers. The method of claim 1, wherein the cooled fibers are stretched to a thickness of 0.01 to 1.0 mm. The process of claim 1 for the preparation of a surgical suture from an elastomer of formula (I) wherein G is a residue after removal of the hydroxyl groups on the polytetramethylene oxide glycol, D is a 1,4-butanediol the residue remaining after removal of the hydroxyl groups, D is the residue remaining after the removal of the hydroxyl groups from the 1,4-butanediol, R is the residue remaining after the removal of the carboxyl groups from the phthalic acid, characterized in that the elastomeric impurity is removed by drying Immediately thereafter, the extruded fibers are cooled with water and the cooled fibers are stretched 5 to 10 times. 4. A process according to any one of claims 1 to 4, characterized in that the drying of the elastomer is carried out at a temperature of at least 93 ° C. 20 5. A process according to any one of claims 1 to 4, characterized in that the dried elastomer is extruded at a temperature of at least 177 ° C. 6. A process according to any one of the preceding claims wherein the extruded fibers are water Cool suddenly to room temperature. 7. A method according to any one of claims 1 to 4, characterized in that the chilled fibers are stretched 7 to 9 times.