DE102014209606B4 - Threads with varying thread diameter and method of manufacturing such threads - Google Patents

Abstract

Thread having a varying thread diameter, comprising:) first thread longitudinal sections along which the thread diameter is constant or substantially constant, and b) at least one second thread longitudinal section along which the thread diameter varies, the first thread longitudinal sections a) being longer than the at least one second thread longitudinal section b ), the thread diameter along the at least one second thread longitudinal section b) varies linearly or substantially linearly, and the thread is a solid thread, characterized in that the thread has a plurality of second thread longitudinal sections b), along which the thread diameter is linear or increases or decreases substantially linearly.

Description

Application area and technical background

The invention relates to yarns with thread diameter varying in the yarn longitudinal direction and to a process for producing such yarns.

From the WO 2007/061475 A2 For example, meltblown nonwoven webs are known as coalescers, wherein the nonwoven web is formed from meltblown polymer fibers, with the diameter of individual fibers varying along their length such that a single fiber has different diameters at different points along its length. The typical diameter of the individual filaments in melt-blow nonwovens lies between 1 μm and 10 μm.

Subject of the WO 99/15470 A1 are silica optical fibers having a varying diameter due to the use of different draw rates during the manufacturing process.

The US 4,631,162 relates to irregular multifilament hollow fibers which have sinusoidal filament constituents.

From the pamphlets JP H09-217221 A and JP H09-217222 A In each case, a raw yarn (vinylidene fluoride) for fly fishing is known, for its production, the extrusion rate and the withdrawal speed of the resulting yarn is varied.

The GB 535,263 discloses the production of tapered filaments for bristles and fishing lines. To produce the filaments, the filament material throughput and the take-off speed of the resulting filaments are varied.

From the pamphlets GB 990 780 A and GB 813 857 A each multifilament emerge, each having a varying diameter in the longitudinal direction. For the production of the multifilaments jet nozzles come with variable diameter ( GB 990 780 A ) as well as guide elements which change the way from the nozzle to the winding in the short term ( GB 813 857 A ), for use.

Subject of the EP 0 270 019 A2 is a multifilament yarn composed of two ribbon-like filamentous constituents, at least one filamentous core constituent, and at least two middle filamentous constituents. The core component extends sinusoidally along the longitudinal axis of the filament.

The US 2012/0010656 A1 relates to a surgical suture having suture portions that differ in diameter.

The US 2013/0101844 A1 relates to profiled individual filaments, which are glued together by means of a spinning process in a stochastic, so random manner, whereby different overall cross-sectional structures can be formed.

From the JP 2000-064116 A is a fiber with a core-shell structure for reinforcing concrete known.

Subject of the EP 2 589 693 A1 is a nanofiber with a cavity, wherein the cavity contains an oily component.

From the US 2013/0337254 A1 is the decoating of a thread with a core-shell structure known.

The EP 0 753 251 A1 discloses a guide for artificial fly fishing. The leader consists of a thick section, a hair cord section and a tapered section therebetween. Both the thick portion and the hair cord portion have a constant diameter, wherein the diameter of the thick portion is larger than the diameter of the hair cord portion.

The threads described in the prior art sometimes have the disadvantage that the variation of the thread diameter can not be sufficiently profiled and defined, which limits their potential application.

Task and solution

It is an object of the invention to provide threads with a varying thread diameter, which in particular circumvent the disadvantages known in the case of generic threads. Furthermore, it is an object of the invention to provide manufacturing methods for such threads. It is a further object of the invention to provide a technical textile, a medical product and a kit, which each have at least one thread with a varying thread diameter.

This is inventively achieved by threads according to claims 1 and 13, a method according to claim 7, a medical product according to claim 14 and a medical kit according to claim 15. Preferred embodiments of the invention are described, for example, in the subclaims, which are hereby incorporated by express reference into the content of the description. Further solutions are discussed in the description.

According to a first aspect, the invention relates to a thread having a varying (changing) thread diameter.

The thread according to the invention has thread longitudinal sections, ie two or more thread longitudinal sections, along which the thread diameter is constant or essentially constant, subsequently as first thread longitudinal sections a ) designated.

In addition, the thread according to the invention has at least one thread longitudinal section along which the thread diameter varies, ie along which the thread diameter changes, subsequently as the at least one second thread longitudinal section b ) designated.

Due to the varying thread diameter, the at least one second thread longitudinal section has b ) extending in the longitudinal direction of the thread gradient with respect to the thread diameter.

The first thread longitudinal sections a ) are longer than the at least one second thread longitudinal section b ), or in other words, the at least one second thread longitudinal section b ) is shorter than the first thread longitudinal sections a ). This makes it possible with particular advantage a "sharper", ie steeper, diameter gradient in the longitudinal direction of the thread or the at least one second thread longitudinal section b ) train.

The present invention is further based on the surprising finding that such a "sharpening" of the diameter gradient, in particular starting from a coextruded core-sheath thread, i. a thread with a core-shell structure (or with a core-shell structure), by subsequent removal of the shell (stripping) can be realized, as will be explained in more detail below.

The term "diameter" used in the present invention with respect to the thread or a longitudinal portion of the thread, unless otherwise defined, is the usual understanding of the art. If anchoring structures, in particular of the type described below, are formed on the thread surface, they will not be added to the thread diameter or the diameter of a longitudinal section of the thread according to the present invention.

The expression "at least a second thread longitudinal section b ) "Means in the context of the present invention, a second thread longitudinal section b ) or a plurality of second thread longitudinal sections b ), ie two or more second thread longitudinal sections b ). Accordingly, the following apply with respect to the at least one second thread longitudinal section b ) made statements mutatis mutandis, in the event that the thread several second thread longitudinal sections b ) having.

Along the at least one second thread longitudinal section b ), the thread diameter increases or decreases linearly or substantially linearly.

A linear or substantially linear increase or decrease in the thread diameter along the at least one second thread longitudinal section b ) is according to the invention.

Preferably, the increase or decrease of the thread diameter is subject along the at least one second thread longitudinal section b ) in an unstretched state of the thread of an absolute pitch of 20 mm per cm thread length to 0.01 mm per cm thread length, in particular 15 mm per cm thread length to 0.02 mm per cm thread length, preferably 10 mm per cm thread length to 0.02 mm per cm thread length. For the purposes of the present invention, the term "absolute slope" is understood to mean the absolute measure, that is to say independent of the sign, of the steepness of a straight line or a curve which characterizes the variation of the thread diameter.

By contrast, after stretching the thread, the values for the absolute gradient can be significantly smaller. Thus, in the stretched state of the thread, the increase or decrease of the thread diameter along the at least one second thread longitudinal section b ) an absolute pitch of 7 mm per cm thread length to 0.002 mm per cm thread length, in particular 5 mm per cm thread length to 0.004 mm per cm thread length, preferably 4 mm per cm thread length to 0.004 mm per cm thread length, follow.

The first thread longitudinal sections a ) may have a total length of 50% to 99%, in particular 70% to 99%, preferably 80% to 99%, based on the total length of the thread. The at least one second thread longitudinal section b ) may have a length fraction of 1% to 50%, in particular 1% to 30%, preferably 1% to 20%, based on the total length of the thread. The length portions described in this paragraph are particularly advantageous for medical uses of the thread.

For non-medical uses of the thread, it may be advantageous if the first thread longitudinal sections a ) Overall, a length proportion of 1% to 50%, in particular 1% to 30%, preferably 1% to 20%, and corresponding to the at least one second thread longitudinal section b ) have a length fraction of 50% to 99%, in particular 70% to 99%, preferably 80% to 99%, in each case based on the total length of the thread.

The first thread longitudinal sections a ) comprise in a further embodiment, at least one thread longitudinal section, ie one or more thread longitudinal sections along which (the) the thread continuously a constant or substantially constant thread diameter d ₁ has, hereinafter referred to as the at least one thread longitudinal section a ₁ ), and at least one thread longitudinal section, ie one or more thread longitudinal sections along which (the) thread continuously a constant or substantially constant thread diameter d ₂ has, hereinafter as the at least one thread longitudinal section a ₂ ), wherein d ₁ > d ₂ is.

In other words, the thread first Fadenlängsabschnitte a ), which differ in diameter from one another. The diameter d ₁ may be from 10% to 200%, in particular from 20% to 200%, preferably from 20% to 100%, greater than the diameter d ₂ ,

The thread points next to the first thread longitudinal sections a ) a plurality, ie two or more, thread longitudinal sections b ), along which the thread diameter increases or decreases linearly or substantially linearly.

The thread longitudinal sections a ) and b ) can occur singly or periodically along the thread. According to the invention, it is preferred if the thread has an alternating sequence of the thread longitudinal sections a ) and b ) having.

• a₁) Fadenlängsabschnitt, entlang dessen der Faden durchgehend einen konstanten oder im Wesentlichen konstanten Fadendurchmesser d₁ besitzt,
• b) Fadenlängsabschnitt, entlang dessen der Fadendurchmesser linear oder im Wesentlichen linear zwischen d₁ und einem Wert d₂ variiert und
• a₂) Fadenlängsabschnitt, entlang dessen der Faden durchgehend einen konstanten oder im Wesentlichen konstanten Fadendurchmesser d₂ besitzt, wobei d₁ > d₂ ist.

In a further embodiment, the thread has a preferably recurring sequence of the following thread longitudinal sections in the longitudinal direction, in particular in the sequence a ₁ ) b ) a ₂ ), on:

• a ₁ ) thread longitudinal section, along which the thread continuously a constant or substantially constant thread diameter d ₁ has,
• b) thread longitudinal section along which the thread diameter is linear or substantially linear between d ₁ and a value d ₂ varied and
• a ₂ ) thread longitudinal section, along which the thread continuously a constant or substantially constant thread diameter d ₂ owns, where d ₁ > d ₂ is.

The total length of the sequence of thread longitudinal sections a ₁ ) b ) a ₂ ) may be in the unstretched state of the thread <30 cm, in particular <20 cm, preferably <10 cm. These overall lengths are particularly advantageous in medical applications of the thread.

The thread may in principle have a circular cross-section or a non-circular cross-section, in particular an oval, ellipsoidal or polygonal, such as triangular, rectangular, square, rhombic, pentagonal, hexagonal or star-shaped cross-section.

Furthermore, the thread may in principle comprise a resorbable, partially absorbable or non-resorbable polymer or a corresponding polymer blend (blend) or be formed from such a polymer or such a polymer blend. The polymer may be a homo- and / or copolymer. The copolymer may in turn be selected from the group comprising random copolymer, segmented copolymer (block copolymer), graft copolymer and mixtures (blends) thereof. For the purposes of the present invention, the term "copolymer" is to be understood as meaning a polymer which is composed of at least two recurring monomer units. For example, according to this definition, the term "copolymer" refers to bipolymers, i. Polymers composed of two preferably repeating monomer units and terpolymers, i. Polymers, which are composed of three preferably recurring monomer units detected.

Preferably, the thread comprises at least one polymer or is formed from at least one polymer which is selected from the group comprising polyolefins, polyamides, polyesters, polycarbonates, polyurethanes, in particular thermoplastic polyurethanes, polyhydroxyalkanoates, copolymers thereof, salts thereof, stereoisomers thereof and mixtures ( Blends) of it.

For example, the thread may comprise at least one polymer or be formed from at least one polymer selected from the group consisting of polyethylene, low density polyethylene, high density polyethylene, high molecular weight polyethylene, ultra high molecular weight polyethylene, polypropylene, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, nylon 6, Nylon 6-6, nylon 6-12, nylon 12, polytetrafluoroethylene, polyvinylidene difluoride, polytetrafluoropropylene, polyhexafluoropropylene, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, polyethylene oxide, polyglycolic acid, polylactic acid, polydioxanone, poly-3-hydroxybutyric acid, poly-4-hydroxybutyric acid, polytrimethylene carbonate, poly -e-caprolactone, copolymers thereof, salts thereof, stereoisomers thereof and mixtures (blends) thereof.

A preferred terpolymer for the thread is composed for example of recurring glycolide, ε-caprolactone and Trimethylencarbonateinheiten and commercially available under the name Monosyn ^® .

In a further embodiment, the thread is provided with at least one additive. In this way, a thread can be realized whose additive proportion varies in the longitudinal direction of the thread. According to the embodiment of the thread provided according to the invention, thread longitudinal sections can be realized along which the proportion of the at least one additive is constant or essentially constant (first thread longitudinal sections a )) and / or thread longitudinal sections, along which the proportion of the at least one additive varies (second thread longitudinal sections b )). The proportion of the at least one additive may vary continuously, preferably linearly or substantially linearly, or discontinuously, in particular stepwise, preferably increasing or decreasing.

The at least one additive may be incorporated into the thread. For example, the at least one additive may be part of a polymer compound used to make the thread. Alternatively or in addition, the at least one additive can coat the thread or be part of a thread coating.

The at least one additive is in particular selected from the group comprising antimicrobial, in particular antibiotic, active ingredients, anti-inflammatory agents, disinfectants, analgesics, scarred drugs, cytostatics, pore-forming substances (chemical or physical), plasticizers, lubricants, dyes, pigments, radioactive substances , radio-opaque substances, nucleating agents, matting agents, density-influencing substances, conductive substances, refractive substances, magnetizable substances and mixtures thereof.

For example, resistance gradients along the at least one yarn longitudinal section can be achieved by adding conductive substances b ), which can be used for example for the production of so-called "smart textiles".

By an additive with refractive substances light optical properties can be transferred to the thread.

Additive dyeing, for example, allows the production of effect threads, in particular surgical threads with tinning effects.

An additive with radioactive substances allows, for example, a use of the thread according to the invention in tumor therapy.

In a particularly preferred embodiment, the thread has anchoring structures. The anchoring structures are preferably intended for anchoring in biological, in particular human and / or animal, tissues.

The anchoring structures preferably protrude from the thread surface. The term "thread surface" means according to the present invention, in particular the thread surface of the first thread longitudinal sections a ) and / or the at least one second thread longitudinal section b ).

The anchoring structures are formed in a further embodiment by means of incisions in the thread.

The anchoring structures can basically be formed in at least one row-shaped arrangement, staggered arrangement, zigzag arrangement, spiral arrangement, randomized arrangement or in combinations thereof in the longitudinal and / or transverse direction, preferably in the longitudinal direction, on the thread surface.

The anchoring structures can furthermore have a unidirectional and / or multidirectional, in particular bidirectional, arrangement on the thread surface. The arrangement of the anchoring structures can in this case in particular in the longitudinal and / or transverse direction of the thread, preferably in the longitudinal direction of the thread, be formed. Unidirectionally arranged anchoring structures are characterized in the sense of the present invention in that they are oriented only in one direction of the thread. Bidirectionally arranged anchoring structures are characterized in the sense of the present invention, however, by the fact that a part of the anchoring structures are oriented in one direction and another part of the anchoring structures in a direction opposite thereto. In particular, in the case of bidirectionally arranged anchoring structures, a part of the anchoring structures can be oriented along a first thread longitudinal section in the direction of a second thread longitudinal section, while another part of the anchoring structures can be oriented along the second thread longitudinal section in the direction of the first thread longitudinal section.

According to the invention, a unidirectional or bidirectional design of the anchoring structures in the longitudinal direction of the thread is preferred.

According to the invention, it may be particularly preferred if the thread has on its surface two rows of bidirectional anchoring structures, which are each arranged offset in the longitudinal direction of the thread and in particular in its circumferential direction by 180 degrees.

In a further embodiment, the anchoring structures are barbed, emblem-shaped, shielded, dandruffed, wedge-shaped, thorn-shaped, in particular roseaten, spiked, arrowed, V-shaped, and / or W-shaped.

The formation of the anchoring structures in the form of barbs is particularly preferred according to the invention.

Further preferably, the anchoring structures are each formed pointed or pointed at their protruding from the thread surface ends.

Basically, the anchoring structures on the first thread longitudinal sections a ) and / or the at least one second thread longitudinal section b ) be formed.

The anchoring structures can in particular only on certain first thread longitudinal sections a ), whereas other first thread longitudinal sections a ) can be free of anchoring structures of the type described above.

Preferably, the anchoring structures are only on the already mentioned thread longitudinal sections a ₁ ) educated. This allows - in the case of a medical thread - achieve improved anchoring with a surrounding body tissue, since the thread longitudinal sections a ₁ ) after application of the thread have the smallest distance to the surrounding body tissue, possibly even be surrounded directly by the body tissue. Furthermore, lower cutting depths are required to form the anchoring structures, which reduces tissue trauma and on top of that the mechanical stability, in particular the linear tensile strength, of the thread can be increased. In the embodiment described in this paragraph, it may optionally be additionally provided anchoring structures on the thread longitudinal sections a ₁ ) immediately adjacent sections of the at least one second thread longitudinal section b ) train. If the cutting depth (for the formation of the anchoring structures) is not changed in relation to the thread longitudinal sections, anchoring structures can be formed on said sections, the size of which increases with increasing distance from the thread longitudinal sections a ₁ ) decreases.

In a further embodiment, the thread is stretched or unstretched.

The thread may further be a monofilament or multifilament, in particular a braided multifilament. In the case of a multifilament-shaped configuration of the thread, its individual filaments, in particular at least a part thereof, have the first thread longitudinal sections a ) and the at least one second thread longitudinal section b ) on.

The thread can furthermore be in the form of an endless thread, in particular continuous monofilament, or of a cut-to-length thread.

The thread of the invention is further a solid thread, i. around a thread without a lumen.

According to a particularly preferred embodiment, the thread is a thread core of a stripped core-sheath thread. In other words, the thread according to the invention is particularly preferably a thread which, starting from a core-sheath-structured thread (or core-sheath construction), is removed by removing the sheath, i. by stripping a thread with core-shell structure, is made.

The thread according to the invention opens up a variety of fields of application, both in the technical and in the medical field.

Thus, the thread according to the invention is generally suitable for the production of technical textiles, in particular in the form of woven, knitted, knitted, laid or nonwoven fabrics. Due to a varying thread diameter, it is possible to achieve gradients in terms of pore size or mesh size and / or with regard to an additive gradient in the textile surface. Due to the varying thread diameter, the thread according to the invention is suitable for example for the production of textiles with light-optical effects that can be used for example as automotive textiles, home textiles and / or for the decoration of furniture and rooms.

Another application of the thread, which can be derived in particular from the presence of thread longitudinal sections with decreasing thread diameter (second thread length sections b)), consists in the production of textile gripping arms.

However, preferred are medical uses of the thread. Thus, the thread is particularly preferably intended for use as a medical, in particular surgical, thread (suture). Further medical uses will be explained in more detail below.

1. i) Coextrudieren einer Fadenkernkomponente und einer Mantelkomponente aus einer formgebenden Auslassöffnung einer Extrusionsvorrichtung unter Ausbildung eines intermediären Fadens mit einem Fadenkern und einem den Fadenkern umgebenden Mantel (Kern-Mantel-Faden, d.h. Faden mit Kern-Mantel-Struktur) und
2. ii) Entfernen des Mantels vom intermediären Faden, d.h. Entmanteln des intermediären Fadens, wobei beim Durchführen von Schritt i) der Massedurchsatz der Fadenkernkomponente und vorzugsweise der Mantelkomponente variiert (geändert) und/oder der intermediäre Faden nach Austritt aus der Auslassöffnung mit einer variierenden (sich ändernden) Geschwindigkeit abgezogen wird.

According to a second aspect, the invention relates to a method for producing a thread, in particular a thread according to the first aspect of the invention. The method comprises the following steps:

1. i) co-extruding a thread core component and a shell component from a shaping outlet opening of an extrusion device to form an intermediate thread with a thread core and a surrounding the thread core coat (core-sheath thread, ie thread with core-sheath structure) and
2. ii) removing the sheath from the intermediate thread, ie stripping the intermediate thread, wherein in performing step i) the mass flow rate of the thread core component and preferably the sheath component varies (changed) and / or the intermediate thread exits the exit port with a varying ( changing) speed is subtracted.

The mantle can basically only partially surround the thread core. According to the invention, it is preferred if the thread core is completely surrounded by the jacket.

By varying the mass throughput of the thread core component and preferably the sheath component and / or by varying the take-off speed of the intermediate thread and by subsequently removing the sheath, thread longitudinal sections can be formed, along which the thread diameter varies (changes), preferably increases or decreases. In that regard, reference is made in particular to the statements made in the context of the first aspect of the invention.

By (substantially) keeping constant the total mass throughput, ie the sum of the mass throughput of the thread core component and the mass throughput of the sheath component, and / or by (substantially) keeping constant the take-off speed of the intermediate thread, an intermediate thread with a constant or essentially constant overall diameter can be obtained realize, wherein the intermediate thread thread longitudinal sections with a constant ratio of thread core to shell component (see the Fadenlängsabschnitte u ₁ ) and u ₃ ) of the 1 ) and thread longitudinal sections with a varying, preferably increasing or decreasing, ratio of thread core to shell component (see the thread longitudinal sections u ₂ ) and u ₄ ) of the 1 ) having. The resulting after removal of the jacket thread (stripped intermediate thread) preferably has thread longitudinal sections, along which the thread diameter is constant or substantially constant, and thread longitudinal sections, along which the thread diameter varies, preferably increases or decreases.

Specifically, by varying the mass throughput of the thread core component and preferably the sheath component, it is particularly advantageous to produce a gradient with respect to the thread core diameter and preferably with respect to the sheath thickness and thus preferably also with respect to the ratio of thread core diameter to sheath thickness.

In a particularly preferred embodiment, the mass flow rate of the thread core component and the mass flow rate of the shell component are varied in a contrasting manner, so that the total mass flow rate composed of the two partial mass flow rates remains constant or substantially constant at any point in time.

For example, a lower mass throughput of the thread core component can be compensated by a correspondingly higher mass throughput of the shell component or vice versa. In this way, the total mass flow rate and thus the total diameter of the intermediate thread, as already mentioned, can be kept constant or substantially constant.

According to the statements made so far, the mass flow rate of the thread core component, and preferably of the shell component, can be varied periodically or occasionally when performing step i). In particular, in an alternating sequence, the mass flow rate of the thread core component, and preferably the sheath component, can be kept constant or substantially constant and varied, or vice versa.

The inventively provided extrusion device usually includes an extruder for the thread core component and an extruder for the shell component. Both extruders can each be operated with their own spinning pump. Furthermore, the extrusion device expediently has a first melt channel for the thread core component and a second melt channel for the jacket component, which as a rule concentrically surrounds the first melt channel in the region of the spinneret. The first and the second melt channel expediently open into a common outlet opening of the extrusion device.

In order to vary the mass throughput of the thread core component and preferably of the shell component, in one preferred embodiment the rotational speed of a spinning pump responsible for the extrusion of the thread core component and preferably the rotational speed of a spinning pump responsible for the extrusion of the shell component are varied.

If the mass throughput of the core component or sheath component is to be reduced, the speed of the spinning pump responsible for the extrusion of the thread core component or the speed of the spinning pump responsible for the extrusion of the sheath component is reduced. If, on the other hand, the mass throughput of the thread core component or sheath component is to be increased, the speed of the spinning pump responsible for the extrusion of the thread core component or the speed of the spinning pump responsible for the extrusion of the sheath component is increased.

For example, in order to form an intermediate thread with a constant or substantially constant thread diameter, the speed of the spin pump responsible for the extrusion of the thread core component can be reduced from 10 revolutions per minute to 5 revolutions per minute and, correspondingly, the speed of the spinning pump responsible for the extrusion of the shell component 5 revolutions / min increased to 10 revolutions / min.

Alternatively, the mass flow rate of the core core component and preferably the sheath component may be varied by controlling the mass flow rate within the aforementioned melt channels, for example by means of controllable switches that reduce or close and, if necessary, increase or open the cross-sectional area of the melt channels, or by means of an adjustable bypass , To vary the take-off speed, preferably the rotational speed of a godet responsible for the withdrawal of the intermediate yarn is varied.

According to the statements made so far, the withdrawal speed of the intermediate thread can be varied periodically or occasionally. In particular, the withdrawal speed of the intermediate thread can be kept constant and varied in alternating sequence or vice versa.

In a particularly preferred embodiment, the withdrawal speed of the intermediate thread is increased while the mass flow rate of the thread core component is lowered. Alternatively, the take-off speed of the intermediate yarn can be lowered while the mass flow rate of the yarn core component is increased. This allows steeper gradients with respect to the ratio of thread core diameter to shell thickness (see the thread longitudinal sections u ₂ ) and u ₄ ) of the 1 ) realize. If these method measures combined with a subsequent removal of the jacket, so can be formed in this way steeper diameter gradients in the longitudinal direction of the stripped thread.

To perform step ii), d. H. In principle, both chemical and physical techniques are considered for removing the sheath from the thread core. For example, the jacket can be removed by dissolving in a solvent in which the filament core is insoluble. Alternatively, the shell can be removed by means of a chemical or enzymatic reaction, such as, for example, hydrolysis, in particular ester hydrolysis. If the melting point of the sheath component is lower than the melting point of the thread core component, a suitable physical method for removing the sheath is, for example, to melt the sheath by means of heat supply and drain it from the thread core. Furthermore, the jacket can be removed by means of a stretching of the intermediate thread by the shell breaks apart during the drawing process and detach from the thread core, in particular mechanically detach leaves.

To form the additive gradient described in the context of the first aspect of the invention, it is provided in a further embodiment that at least one additive is added in varying amounts to the thread core component. With regard to suitable additives, reference is made in full to what has been said in the context of the first aspect of the invention.

The core component and / or the sheath component may in principle comprise a resorbable, partially absorbable or non-resorbable polymer or a corresponding polymer mixture (blend) or be formed from such a polymer or such a polymer mixture. In that regard, reference is also made to the statements made in the context of the first aspect of the invention.

Preferably, the thread core component and / or the sheath component comprise at least one polymer or are formed from at least one polymer which is selected from the group comprising Polyolefins, polyamides, polyesters, polycarbonates, polyurethanes, especially thermoplastic polyurethanes, polyhydroxyalkanoates, copolymers thereof, salts thereof, stereoisomers thereof, and mixtures (blends) thereof.

For example, the thread core component and / or the sheath component may comprise at least one polymer or be formed from at least one polymer selected from the group consisting of polyethylene, low density polyethylene, high density polyethylene, high molecular weight polyethylene, ultra high molecular weight polyethylene, polypropylene, polyethylene terephthalate, polypropylene terephthalate, Polybutylene terephthalate, nylon 6, nylon 6-6, nylon 6-12, nylon 12, polytetrafluoroethylene, polyvinylidene difluoride, polytetrafluoropropylene, polyhexafluoropropylene, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, polyethylene oxide, polyglycolic acid, polylactic acid, polydioxanone, poly-3-hydroxybutyric acid, poly-4- hydroxybutyric acid, polytrimethylene carbonate, poly-ε-caprolactone, copolymers thereof, salts thereof, stereoisomers thereof, and mixtures (blends) thereof.

In principle, the thread can be left in an unstretched state.

However, in an embodiment which is advantageous in terms of stability, the thread is drawn. Drawing of the thread may take place before or after performing step ii), i. Stripping the intermediate thread, be made.

The stretching is preferably carried out under heat, in particular in a temperature range from 20 ° C to 140 ° C. To generate a heat advantageous for the stretching, for example, infrared rays, electrically heated continuous furnaces, tempered water baths or chambers with steam can be used. For drawing, the thread can be guided over a roll or godet system, a so-called draw line. The rollers or godets can in this case have different speeds of rotation. Preferably, each successive roll or godet has a higher rotational speed than the preceding roll or godet of the draw line. Alternatively, the last roll or galette of such stretch line may be up to 15% slower than the penultimate roll or godet of the draw line, thereby relaxing with an increase in the elasticity of the thread. As an alternative to the continuous drawing just described, the thread can be stretched discontinuously. For a discontinuous stretching, the thread can be clamped between the clamping jaws of a tensioning device and then stretched under the effect of temperature.

The orientation can generally be carried out with a draw ratio of 1.5 to 12, in particular 2.5 to 10, preferably 3.0 to 8.

In a preferred embodiment, anchoring structures, in particular anchoring structures projecting from the surface of the intermediate thread, or - after performing step ii) - anchoring structures projecting from the surface of the stripped thread, are produced. The anchoring structures are preferably intended for anchoring in biological, in particular human and / or animal, tissues.

Particularly preferably, the anchoring structures are produced in the form of barbs on the surface of the thread. The anchoring structures are preferably produced by means of incisions in the thread. The production of the anchoring structures can be carried out before or after carrying out step ii).

If the anchoring structures are produced by means of cuts in the intermediate thread, it may be expedient to set the cutting depth such that it is greater than the thickness of the jacket. In this way it is ensured that the thread core of the intermediate thread is also cut.

The anchoring structures are produced in a further embodiment only on thread longitudinal sections of the intermediate thread whose core diameter is greater than the shell thickness. In this way, comparatively small cutting depths are sufficient to ensure a cutting of the thread core. In addition, the mechanical stability, in particular the linear tensile strength, of the resulting yarn is greater.

On the other hand, if the anchoring structures are made after performing step ii), i. After the jacket has been removed from the thread core, it is preferred if the anchoring structures are (only) formed on thread longitudinal sections with a thicker thread diameter.

The anchoring structures can basically be generated thermally, for example by means of a laser, and / or mechanically, for example by means of a corresponding cutting device. Suitable cutting devices suitably comprise a cutting bed, at least one cutting blade and holding devices for the thread to be cut. With particular advantage, a cutting bed with a groove can be used for the mechanical cutting of the anchoring structures, wherein the groove is provided for receiving the intermediary thread to be cut or - after performing step ii) - of the stripped thread to be cut.

The anchoring structures can basically be produced in a stretched or unstretched state of the intermediate thread or stripped thread. In particular, the anchoring structures can be produced before or after stretching the intermediate thread or stripped thread.

Preferably, the intermediate thread or stripped thread is cut before or after stretching to create the anchoring structures.

If the intermediate thread or stripped thread is cut in front of a pre-stretch, ie in the still unstretched state, anchoring structures protruding from the thread surface can be produced by means of a subsequent stretching, in particular by forming special geometries depending on the cutting distance, cutting depth and cutting angle. Preferably, such an incised, stripped thread after stretching over its entire length has a constant or substantially constant diameter, a so-called effective thread diameter. For the purposes of the present invention, the term "effective thread diameter" is understood to mean the residual diameter of a thread according to the invention after the production of anchoring structures, preferably by means of incising, and after stretching (see 8th ). This ensures a nearly equal in all longitudinal thread lengths linear tensile force and in particular allows a needling of the thread using small needle diameter.

In contrast, by means of incising a stretched intermediate thread or a stretched, stripped thread directly, i. without the inclusion of a further step, anchoring structures projecting from the thread surface are produced.

In a further embodiment, the thread to be produced may be an endless thread, in particular an endless monofilament, or a cut thread, in particular in the form of a monofilament.

In principle, the thread can be cut to length even before carrying out step ii). In other words, it may be provided according to the invention that the intermediate thread is cut to length.

However, it is preferred if the thread is only after performing step ii), i. E. the stripped thread is cut to length, in particular to obtain the final thread to be produced.

In a further embodiment, after performing step ii) and in particular after stretching, the thread is subjected to a post-treatment, a so-called "post-treatment". In general, the thread is tempered for this purpose in a vacuum. As a result, the crystallinity of the thread can be increased and in particular the residual monomer content of the thread can be lowered. Another advantage that can be achieved by such a treatment is a reduced susceptibility of the thread to shrinkage.

With regard to further features and advantages of the method, in particular threads that can be produced thereby, reference is made to the statements made in the context of the first aspect of the invention.

According to a third aspect, the invention relates to a thread having a varying in the longitudinal direction of the thread (changing) thread diameter, which is produced or produced by a method according to the invention according to the second aspect of the invention.

In the embodiments described below, the thread is preferably stretched.

In the case of a needling, the corresponding thread longitudinal section is preferably completely received by a fastening device of a surgical needle. As a result, an improved filling of a needle channel caused by the needle is possible. In general, by combining a thread according to the invention with a surgical needle (or possibly two surgical needles), ratios of needle diameter to thread diameter ≦ 1, in particular <1, can be realized.

The thread preferably has at least one first thread longitudinal section a), along which the thread diameter is constant or substantially constant throughout, and at least one second thread longitudinal section b ), along which the thread diameter varies (changes), preferably increases or decreases.

An increase or decrease in the thread diameter along the at least one second thread longitudinal section b ) may be continuous, in particular linear or substantially linear, or discontinuous, in particular stepped, take place.

The at least one first thread longitudinal section a ) and the at least one second thread longitudinal section b) preferably directly adjoin one another.

For anchoring in biological, in particular human and / or animal, tissues, the thread has anchoring structures in another embodiment. The anchoring structures preferably protrude from the thread surface.

The anchoring structures are preferably (only) formed on the surface of the at least one first longitudinal thread segment a).

According to the invention, it can further be provided that the anchoring structures are additionally also formed on a partial section of the at least one second thread longitudinal section b), wherein the partial section preferably directly adjoins the at least one first longitudinal thread section a ) adjoins.

The anchoring structures are preferably formed in a unidirectional arrangement in the previous embodiments. In the case of a medical use of the thread is preferably the at least one second thread longitudinal section b ) for attachment to a surgical needle, ie for a Benadelung provided.

In a further embodiment, the thread has a thread longitudinal section a ₁ ), along which the thread has a constant diameter throughout d ₁ has, a thread longitudinal section a ₂ ), along which the thread has a constant diameter throughout d ₂ has, as well as a thread longitudinal section b ), wherein the thread longitudinal section b) preferably between the thread longitudinal sections a ₁ ) and a ₂ ) is arranged. Along the thread longitudinal section b ) varies the thread diameter, wherein thread diameter preferably increases or decreases. The thread longitudinal section a ₁ ) is preferably longer than the yarn longitudinal section a ₂ ). Anchoring structures are preferred in this embodiment on the thread longitudinal section a ₁ ) and optionally on a section of the thread longitudinal section b ), wherein the partial section preferably directly to the thread longitudinal section a ₁ ) adjoins. Also in this embodiment, anchoring structures preferably have a unidirectional arrangement. In the case of medical use of the thread, it is also preferred if the thread longitudinal section a ₂ ) is provided for a Benadelung.

In an alternative embodiment, the thread has a thread longitudinal section a ₁ ) of the type described above, two thread longitudinal sections b ) and optionally two thread longitudinal sections a ₂ ) of the type described above. The thread longitudinal section a ₁ ) is preferably arranged between the two thread longitudinal sections b). The two optionally provided Fadenlängsabschnitte a ₂ ) can each directly to one of the two thread longitudinal sections b ). The two thread longitudinal sections b ) can have the same length. The optionally provided thread longitudinal sections a ₂ ) may also be the same length. Preferably, the thread longitudinal section a ₁ ) longer than each of the two thread longitudinal sections b ) and in particular as each of the two optionally provided Fadenlängsabschnitte a ₂ ). In particular, the thread can have two rows of bidirectionally formed anchoring structures, which are offset by 180 degrees in the circumferential direction of the thread. The anchoring structures on the thread longitudinal section are preferred a ₁ ) and optionally directly to the thread longitudinal section a ₁ ) adjoin sections of the thread longitudinal sections b ) educated. The anchoring structures are preferably symmetrical to the thread center, in particular to the center of Thread longitudinal section a ₁ ). In the case of medical use of the thread, it is preferred if the thread longitudinal sections b ) or the optionally provided Fadenlängsabschnitte a ₂ ) each are needled (see 6a ).

In a further embodiment, anchoring structures differ on the at least one first thread longitudinal section a ) are formed, not from each other.

However, anchoring structures of the at least one first thread longitudinal section can a ) of those of the at least one second thread longitudinal section b ). This applies in particular in relation to anchoring structures that are located on a section of the at least one second thread longitudinal section b ) are formed, which directly to the at least one first thread longitudinal section a ) adjoins. Differences may exist in terms of shape, length, aspect ratio, angle and / or orientation.

In a further embodiment, anchoring structures of the at least one second thread longitudinal section differ b ) with respect to certain properties, such as shape, length, aspect ratio, angle and / or orientation. If the anchoring structures are produced in the form of incisions, the differences are due to the fact that the depth of the incisions decrease in the direction of decreasing thread diameter.

With regard to further features and advantages of the thread, as far as possible, reference is made to the statements made in the context of the present invention aspects.

A fourth aspect of the invention relates to a thread having a varying (changing) thread diameter in the longitudinal direction of the thread, wherein the thread is a thread core of a stripped core-sheath thread, i. a thread formed or made from a thread having a core-shell structure by removing the shell (stripping). Preferably, the core-sheath structure thread is an intermediate, i. occurring as an intermediate, thread and thus in the inventive thread to a stripped intermediate thread.

The thread has at least a first thread longitudinal section a ), ie a first thread longitudinal section a ) or a plurality of first thread longitudinal sections a ), ie two or more first thread longitudinal sections a ) along which the thread diameter is constant or substantially constant.

In addition, the thread has at least one second thread longitudinal section b ), ie a second thread longitudinal section b ) or a plurality of second thread longitudinal sections b ), ie two or more second thread longitudinal sections b ), along which the thread diameter varies (changes), preferably increases or decreases.

The thread diameter can vary along the at least one second thread longitudinal section b) continuously, in particular linearly or substantially linearly, or discontinuously, in particular stepwise, preferably increase or decrease.

An increase or decrease in the thread diameter along the at least one second thread longitudinal section b ) In the unstretched state of the thread an absolute pitch of 20 mm per cm thread length to 0.01 mm per cm thread length, in particular 15 mm per cm thread length to 0.02 mm per cm thread length, preferably 10 mm per cm thread length to 0.02 mm per cm thread length subject ,

With regard to further features and advantages of the thread, as far as possible, reference is also made to the statements made in the context of the present invention aspects.

According to a fifth aspect, the invention relates to a medical product which comprises at least one thread according to the invention, preferably a plurality of threads according to the invention.

The medical product is preferably a surgical implant, particularly preferably a medical, in particular surgical, thread (medical, in particular surgical suture).

The medical product can basically have a textile structure or be formed from such a structure, which is selected from the group comprising tissue, knitted fabric, knitted fabric, mesh, scrim, fleece and combinations thereof.

The medical product may in particular have a network or be made as a network.

Furthermore, the medical product may have a textile fabric or be in the form of such a fabric.

The medical product may further comprise a hollow body structure, in particular a tubular structure, or be in the form of such a structure.

In a further embodiment, the medical product is selected from the group comprising hernia mesh, prolapse mesh, wound dressing, hemostyptics, venous patch, implant for dura mater replacement, vascular prosthesis, in particular arterial vascular prosthesis, stent graft, stent and occluder.

In another embodiment, the medical product is intended for use as a nerve guide.

With regard to further features and advantages of the medical product, reference is also made, as far as possible, to the statements made in the context of the present invention aspects.

According to a sixth aspect, the invention relates to a kit, in particular in the form of a needle-thread combination, comprising at least one surgical needle, in particular two surgical needles, and at least one thread according to the invention or a medical product according to the invention.

The at least one needle as well as the at least one thread or the medical product may be spatially separated from each other. Alternatively, the at least one thread or medical product may already be needled.

For the needling, a longitudinal section of the at least one thread or the medical product is preferably completely received by a fastening device of the at least one surgical needle. This makes possible an improved filling of a puncture channel caused by the at least one needle. In general, by combining a thread according to the invention with a surgical needle (or possibly two surgical needles), ratios of needle diameter to thread diameter ≦ 1, in particular <1, can be realized.

For threads with bidirectionally formed anchoring structures, a needling is preferably carried out at both ends of the thread.

For threads with undirectionally formed anchoring structures, a needling is preferably carried out at the thread end, which is opposite to the orientation (direction) of the anchoring structures. The other end of the thread is preferably formed either as a loop, stopper or cable tie-like structure, whereby a fixation of the thread in biological, especially human and / or animal, tissues is made possible as a starting point for a continuous seam.

The at least one needle may be formed either straight or curved.

Furthermore, the at least one needle may be formed at its expediently pointed end either cutting or provided with a round tip.

In order to accommodate the at least one thread or the medical product, the at least one needle in another embodiment has at its tip end a borehole into which the at least one thread or medical product is inserted and subsequently fixed to the at least one needle, for example by squeezing can be.

With regard to further features and advantages of the medical kit, as far as possible, reference is also made to the statements made within the scope of the present invention aspects description.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments in the form of figures, character descriptions and embodiments and the dependent claims. In this case, individual features can be realized individually or in combination with each other. The preferred embodiments are merely for further explanation and understanding of the invention without limiting it thereto.

• 1: einen intermediären Faden gemäß zweitem Erfindungsaspekt,
• 2a: einen Querschnitt des Fadenlängsabschnittes u₁),
• 2b: einen Querschnitt des Fadenlängsabschnittes u₂),
• 3: eine Ausführungsform eines erfindungsgemäßen Fadens,
• 4: einen graphischen Vergleich des Fadendurchmessers zwischen einem erfindungsgemäßen Faden und einem aus dem Stand der Technik bekannten monofilen Faden,
• 5: eine Ausführungsform einer erfindungsgemäßen Nadel-Faden-Kombination,
• 6a: eine Ausführungsform einer erfindungsgemäßen Kombination aus einer chirurgischen Nadel und einem unverstreckten Faden mit Einschnitten,
• 6b: eine weitere Ausführungsform einer erfindungsgemäßen Nadel-Faden-Kombination,
• 7a: eine aus dem Stand der Technik bekannte Kombination aus einer chirurgischen Nadel und einem unverstreckten Faden mit Einschnitten,
• 7b: eine aus dem Stand der Technik bekannte Nadel-Faden-Kombination,
• 8: einen erfindungsgemäßen Faden mit Verankerungsstrukturen,
• 9: zeigt graphisch den Durchmesserverlauf des Fadenkerns des gemäß Beispiel 1 hergestellten intermediären Fadens,
• 10: zeigt graphisch den Durchmesserverlauf des gemäß Beispiel 2 entmantelten Monofilaments,
• 11: zeigt graphisch den Durchmesserverlauf der gemäß Beispiel 3 hergestellten Monofilamente,
• 12: zeigt graphisch Außen- und Effektivdurchmesser des gemäß Beispiel 5 hergestellten unverstreckten Fadens nach Einschneiden und Entmanteln,
• 13: zeigt graphisch Durchmesser (Außen- bzw. Effektivdurchmesser) und Top-Top-Abstand des gemäß Beispiel 5 hergestellten verstreckten Fadens,
• 14a,b: zeigen graphisch den Außen- und Effektivdurchmesser der gemäß den Beispielen 6 und 7 hergestellten Fäden im jeweils unverstreckten Zustand,
• 15a,b: zeigen graphisch den Durchmesser (Außen- bzw. Effektivdurchmesser) und Top-Top-Abstand der gemäß den Beispielen 6 und 7 hergestellten Fäden im jeweils verstreckten Zustand,
• 16: zeigt graphisch den Außen- und Effektivdurchmesser des gemäß Vergleichsbeispiel 8 eingeschnittenen Fadens im unverstreckten Zustand und
• 17: zeigt graphisch den Durchmesser (Außen- bzw. Effektivdurchmesser) und Top-Top-Abstand des gemäß des Vergleichsbeispiels 8 hergestellten Fadens im verstreckten Zustand.

In the figures show schematically:

• 1 : an intermediate thread according to the second aspect of the invention,
• 2a a cross-section of the thread longitudinal section u ₁ ),
• 2 B a cross section of the thread longitudinal section u ₂ ),
• 3 an embodiment of a thread according to the invention,
• 4 FIG. 2: a graphic comparison of the thread diameter between a thread according to the invention and a monofilament thread known from the prior art, FIG.
• 5 : an embodiment of a needle-thread combination according to the invention,
• 6a FIG. 5 shows an embodiment of a combination according to the invention of a surgical needle and an unstretched thread with incisions, FIG.
• 6b a further embodiment of a needle-thread combination according to the invention,
• 7a a combination of a surgical needle and an unstretched thread with incisions known from the prior art,
• 7b a needle-thread combination known from the prior art,
• 8th : a thread according to the invention with anchoring structures,
• 9 FIG. 4 shows graphically the diameter profile of the thread core of the intermediate thread produced according to Example 1, FIG.
• 10 FIG. 2 is a graph showing the diameter profile of the monofilament stripped according to Example 2;
• 11 FIG. 4 is a graph showing the diameter profile of the monofilaments produced according to Example 3, FIG.
• 12 FIG. 2 is a graph showing outer and effective diameters of the undrawn thread produced according to Example 5 after cutting and stripping, FIG.
• 13 : graphically shows diameter (outer diameter or effective diameter) and top-to-top distance of the drawn thread produced according to Example 5,
• 14a, b FIG. 4 graphically shows the outer diameter and effective diameter of the filaments produced according to Examples 6 and 7 in the respectively unstretched state, FIG.
• 15a, b FIG. 4 graphically shows the diameter (outer diameter or effective diameter) and top-to-top spacing of the filaments produced according to Examples 6 and 7 in the respectively drawn state, FIG.
• 16 : graphically shows the outer diameter and the effective diameter of the thread cut in Comparative Example 8 in the unstretched state and FIG
• 17 : Graphically shows the diameter (outer diameter and effective diameter) and top-top distance of the yarn produced according to Comparative Example 8 in the stretched state.

figure description

1 schematically shows a longitudinal section of an intermediate thread 1 according to the second aspect of the invention. The intermediate thread 1 has a thread core 100 as well as the thread core 100 surrounding coat 200 on. In other words, the intermediate thread 1 has a core-shell structure.

The intermediate thread 1 has a (substantially) constant (outer) thread diameter d.

The intermediate thread 1 can be further in the thread longitudinal sections described below u ₁ ) u ₂ ) u ₃ ) and u ₄ ).

The thread longitudinal sections u ₁ ) and u ₃ ) each have a constant shell thickness and a constant thread core diameter. While the shell thickness of the thread longitudinal sections u ₁ ) is smaller than the cladding thickness of the thread longitudinal sections u ₃ ), the yarn core diameter is reversed, ie the yarn core diameter of the yarn longitudinal sections u ₁ ) is greater than the yarn core diameter of the yarn longitudinal sections u ₃ ).

Along the thread longitudinal sections u ₂ ) and u ₄ ) vary both the shell thickness and the thread core diameter. At the in 1 The embodiment shown embodiment takes the shell thickness along the thread longitudinal sections u ₂ ) linear to and the thread core diameter accordingly linearly. At the thread longitudinal sections u ₄ ) it behaves vice versa. There, the thread core diameter along the Fadenlängsabschnitte takes u ₄ ) linear, whereas the shell thickness of the thread longitudinal sections u ₄ ) decreases linearly.

The intermediate thread + -1 has a preferably recurring sequence of the thread longitudinal sections in the longitudinal direction u ₁ ) u ₂ ) u ₃ ) and u ₄ ).

2a schematically shows a cross section of the in 1 shown Fadenlängsabschnittes u ₁ ) and clarifies that the diameter of the thread core 100 along this thread longitudinal section is greater than the thickness of the shell 200 ,

2 B schematically shows a cross section of the in 1 shown Fadenlängsabschnittes u ₂ ). In the cross section shown is the thickness of the jacket 200 greater than the diameter of the thread core 100 ,

3 schematically shows an embodiment of a thread according to the invention 100 by stripping the in 1 represented intermediate thread 1 is available.

The string 100 is preferably stretched before.

The string 100 has thread longitudinal sections a ₁ ) with a constant or substantially constant thread diameter d ₁ and thread longitudinal sections a ₂ ) with a constant or substantially constant thread diameter d ₂ on, where d ₁ > d ₂ is.

Furthermore, the thread has thread longitudinal sections b ), along which the thread diameter varies (changes).

At the in 3 illustrated embodiment, the thread 100 several thread longitudinal sections b ), along which the thread diameter is (substantially) linearly from d ₁ to d ₂ decreases, as well as several thread longitudinal sections b ) along which the thread diameter is (substantially) linear from d ₂ on d ₁ increases.

Overall, the thread has 100 a recurring sequence of the thread longitudinal sections a ₁ ), Federation a ₂ ), resulting in an alternating sequence of thread length sections with constant thread diameter and thread longitudinal sections with varying thread diameter.

The thread longitudinal sections b ) represent gradient regions in relation to the thread diameter.

4 shows graphically the course of the thread diameter in the longitudinal direction in a thread according to the invention, which was prepared from a thread with a core-shell structure by subsequent removal of the jacket was made (stripped core-sheath thread), and a generic monofilament thread.

The ordinate indicates the diameter in mm. On the abscissa, the thread longitudinal position is given in cm.

The graph shows that the thread according to the invention has cleanly formed plateaus, along which the thread diameter is (essentially) constant and at the same time has "sharp" (steep) gradient regions, along which the thread diameter varies almost linearly.

In contrast, the thread diameter in the generic thread shows a more sinusoidal course without recognizable plateau structures and with much flatter gradient areas.

5 schematically shows an embodiment of a thread-needle combination according to the invention 105 , The combination 105 is from a thread according to the invention 100 and a surgical needle 110 composed. At the thread 100 it is a thread that starts from the in 1 represented intermediate thread 1 can be obtained by removing the shell and by cutting to length (before or after removal of the shell).

The string 100 is from a stretched thread longitudinal section a ₁ ), a stretched thread longitudinal section b ) and a stretched thread longitudinal section a ₂ ). The thread longitudinal sections a ₁ ) and a ₂ ) each have a (substantially) constant thread diameter, wherein the thread diameter of the thread longitudinal section a ₁ ) is greater than the diameter of the thread longitudinal section a ₂ ).

Along the thread longitudinal section b On the other hand, the thread diameter changes preferably (substantially) linearly from the diameter of the thread longitudinal section a ₁ ) on the diameter of the thread longitudinal section a ₂ ) or vice versa. For attachment with the surgical needle 110 is the thread longitudinal section a ₂ ) into a borehole of the needle 110 introduced and attached, for example by squeezing with the needle end. The outer diameter of the needle 110 preferably corresponds (substantially) to the diameter of the thread longitudinal section a ₂ ). According to the invention, it is therefore possible with particular advantage to realize a needle-to-thread diameter ratio of approximately 1: 1, which avoids puncture channel bleeding, but at least can be reduced significantly. In contrast, conventional needle-and-thread combinations have needle-to-thread diameter ratios that are significantly larger, typically ranging from 2: 1 to 4: 1.

6a shows schematically an embodiment of a combination according to the invention 105 from a surgical needle 110 and an undiluted thread 100 ' , The string 100 ' is from a thread longitudinal section a ₁ ), two longitudinal thread sections b ) and two thread longitudinal sections a ₂ ). During the thread longitudinal section a ₁ ) between the two thread longitudinal sections b ) are arranged, the thread longitudinal sections b ) in each case between the thread longitudinal section a ₁ ) and one of the two thread longitudinal sections a ₂ ) arranged. The thread longitudinal sections a ₂ ) thus form the ends of the thread 100 ' ,

The string 100 ' has on its surface two rows of bidirectionally arranged anchoring structures 120 ' on that over cuts 118 ' objected to each other. The anchoring structures 120 ' are in the circumferential direction of the thread 100 ' arranged offset by 180 degrees to each other. The anchoring structures 120 ' are on the thread longitudinal section a ₁ ) and in each case on a section of the thread longitudinal sections b ), which directly adjoins the thread longitudinal section a ₁ ) adjacent, arranged. By a subsequent drawing operation, the anchoring structures can be 120 ' in anchoring structures projecting from the thread surface 120 convict as in 6b shown.

6b shows a further embodiment of a needle-thread combination according to the invention 105 , The combination 105 is from a thread 100 by stretching the in 6a shown thread 100 ' available, as well as two surgical needles 110 ; 130 composed.

The in 6b illustrated thread 100 distinguishes itself from generic filaments in particular in that it has an effective filament diameter that is constant over the entire filament length (FIG. d _eff ) having. Furthermore, the thread is characterized 100 characterized by the size of the anchoring structures 120 coming from the anchoring structures 120 ' the thread longitudinal section b ) of the thread 100 ' have grown towards the center of the thread, whereas the anchoring structures increase 120 coming from the anchoring structures 120 ' the thread longitudinal section a ₁ ) of the thread 100 ' they do not differ in size.

7a schematically shows a known from the prior art combination 5 from an unstretched thread 10 ' whose thread diameter is constant over the entire thread length. The string 10 ' has on its surface two rows of bidirectionally arranged anchoring structures 20 ' arranged in the circumferential direction of the thread offset by 180 degrees from each other and via incisions 18 ' spaced apart from each other. By a subsequent drawing operation, the anchoring structures can be 20 ' in anchoring structures projecting from the thread surface 20 convict as in 7b shown.

7b shows a combination known from the prior art 5 , The combination 5 is from a thread 10 by stretching the in 7a shown thread 10 ' available, as well as two surgical needles 10 ; 30 composed. Unlike the in 6b shown thread 100 owns the thread 10 in the region of its ends (outside the longitudinal section with the anchoring structures 20 ) a much larger thread diameter than the effective thread diameter d _eff in the field of anchoring structures. This in turn requires the use of surgical needles with a correspondingly larger outside diameter. The larger outer diameter forms a larger puncture channel, in which the anchoring structures can anchor less well with a surrounding body tissue. In addition, the linear tensile force along the yarn longitudinal section with the anchoring structures is significantly lower than the linear tensile force along the yarn longitudinal sections without anchoring structures.

8th schematically shows an enlarged detail of the in 6b shown thread 100 , 8th clarifies once again that the thread 100 a constant effective diameter over the entire thread length (essentially) d _eff and anchoring structures 120 which differ (in part) in size from each other.

example part

Example 1 Production of a Core-Shell Monofilament Having a Thread Core of Poly-p-dioxanone (PDO) and a Jacket of Poly-ε-caprolactone (PCL) with an Alternate Core-Sheath Ratio (Intermediate Thread According to the Second Invention Aspect)

The core-sheath monofilament was produced on a bicomponent monofilament extrusion line consisting of a single-screw extruder with two heating zones (core component) and a co-rotating twin-screw extruder with 6 heating zones (jacket) and a metering station for underfeeding the extruder. Both melt streams were conveyed via separate spinning pumps (4 × 0.25 cc / rev) in the spinneret to the spinnerets (4 places) and finally united in the spinneret to the core-shell structure. The nozzles had a diameter of 1.5 mm at the outlet opening. The core component was supplied via a centric capillary, which ends in front of the nozzle outlet opening, while the jacket component annularly surrounded the central capillary. After exiting the die, the bicomponent strands passed through a water bath (T = 20 ° C.) for solidification, were subsequently drawn off via a godet system and wound up by means of a winder. Between the godet system and the winder was a double-axis laser diameter gauge for determining the monofilament diameter.

To achieve the sequence of thread longitudinal areas u ₁ ) (high core), u ₂ ) (decreasing core), u ₃ ) (low core share) and u ₄ ) (increasing core fraction), the control of the bicomponent plant was modified to allow separately for the spinning polymer of the core polymer and for the spin polymer of the shell polymer, respectively, a starting value for the spinning pump speed [rpm] and a range (± rpm) within which the spinning pump speeds were varied. The spinning pump speed variation was inverse: by the time the spinning pump speed of the core polymer increased, the spinning polymer spinning speed of the sheath polymer was reduced. Furthermore, for both spinning pumps together a holding time t _H predetermined, during which the spinning pump speeds were kept constant at their maximum or minimum, and a ramp time t _R during which the spinning pump speed either increased from minimum to maximum or dropped from maximum to minimum. The length of the constant areas u ₁ ) and u ₃ ) resulted from the holding time, multiplied by the withdrawal speed, the length of the varying ranges of the ramp time multiplied by the withdrawal speed. For this experiment, the parameterization was as follows: Holding time t _H : 2s Ramp time t _R : 1 s Off speed: 1.4 m / min Spinning pump core: 3.2 rpm ± 1.2 rpm Spinning pump jacket: 3.2 rpm ± 1.2 rpm Temperature profile core extruder: 140 ° C / 160 ° C Temperature profile jacket extruder: all zones 190 ° C Spin head temperature: 190 ° C

The diameter of the bicomponent bicomponent monofilament was substantially constant at 1.196 mm ± 0.025 mm over the entire run time.

In order to be able to make initial statements about the quality (precision of the constant diameter ranges and steepness of the varying regions) of the diameter profile of the core component, cross-sections were made at a distance of 1 cm along the longitudinal axis of the thread and measured microscopically.

The resulting diameter of the thread core over the longitudinal axis is graphically in the 9 shown. The ordinate shows the diameter in mm, the abscissa shows the length of the thread in cm. As can be seen, despite the extremely short holding and ramping time, bicomponent technology, which ensures consistent overall mass flow rate, forms a very precise diameter profile with clean imaging of the plateaus and gradients.

Example 2: stripping of the intermediate monofilament from example 1 (according to the second aspect of the invention)

The sheath polymer PCL of the intermediate monofilament of Example 1 has a melting point of 60 ° C and is well soluble in toluene, while the core polymer PDO is insoluble in toluene and has a melting point of 105 ° C to 110 ° C. These differences in the behavior of both polymers were used to detach the cladding from the filament core at T = 65 ° C in toluene. This process can be carried out continuously in heated solvent baths, which passes through the intermediate thread, but also discontinuously in the cut-to-length state. For simplicity, the discontinuous process was chosen here: For this purpose, 50 cm long pieces of thread were placed for 10 min in toluene at T = 65 ° C and then washed in a second vessel in toluene at room temperature, stripped off the solvent and the pieces of thread dried overnight. A subsequently measured NMR spectrum contained no signals from PCL. The stripping of the intermediate thread was thus completely.

The stripped monofilament was characterized microscopically with respect to the diameter course on three pieces of thread, wherein the starting position of the investigation was chosen arbitrarily. In 10 the diameter profile of the stripped Monfilaments is shown graphically. The ordinate shows the diameter in mm, the abscissa shows the length of the thread in cm. 10 shows an excellent formation of the diameter profile with precise formation of the plateaus and sharp and reproducible formation of the gradient (slope about 0.2 mm / cm).

In contrast, the gradient monofilament produced by monocomponent technology according to Example 3 below exhibits a rather sinusoidal diameter profile due to the viscoelastic behavior of the polymer and the changing mass throughput and hence variable spinning distortions.

Example 3: Monocomponent monofilaments of variable diameter PDO

A overnight dried at 80 ° C in vacuo (6 mbar) PDO polymer was on a single screw extruder with two heating zones (T = 140 ° C / 160 ° C) with variation of the spinning pump speed with a monocomponent spinneret to monofilaments with along the Filament longitudinal axis of varying diameter sections processed under the following parameterization: Tab. 1: Parametrization of the gradient mono-component extrusion from Example 3 Example 3 a Example 3 b Holding time t _H [s] 2 8th Ramp time t _R [s] 1 2 Spinning pump [rpm] 5.9 ± 0.9 5.9 ± 0.9 Spinning head temperature [° C] 190 190 Nozzle diameter [mm] 1.5 1.5 Withdrawal speed [m / min] 3.2 3.2

In contrast to Example 1, no second polymer component (sheath) was coextruded, which is why, in contrast to the intermediate bicomponent thread of Example 1, the extruded strand did not have a substantially constant outer diameter, but, as in the stripped thread of Example 2, a thread with varying Diameter along its longitudinal axis trained. The diameter profile of the extruded strands could be determined directly with a double-axis laser measuring device and is graphically in the 11 shown. The ordinate shows the diameter in mm, the abscissa shows the length of the thread in cm.

It can be seen that, with monocomponent technology, with short thread longitudinal sections aimed for, in contrast to example 2 produced by coextrusion, only sinusoidal courses (example 3a) can be realized rather than the formation of plateaus. Only when significantly increasing the holding time of the spinning pump speed (Example 3b) succeeded in the formation of plateaus, the diameter profile was far from being as accurate as in the thread produced according to Example 2. For numerous medical applications, in particular for a surgical suture and especially in the production of suture material with anchoring structures, but on the one hand precise diameter courses are required, and on the other it is advantageous if the plateaus and the gradient on as short a thread section are formed. This applies more and more to applications in which, in order to increase the tensile strength and to reduce elongation, a stretching operation has to be carried out in which the yarn longitudinal sections are elongated by the drawing factor.

Example 4: Drawing, lengthening and needling of the stripped monofilament from Example 2 as a stitch channel occluding monofilament

The stripped piece of thread from example 2 was stretched in a discontinuous stretching device, consisting of a heated oven, a stationary and a mobile clamp, at T = 80 ° C to five times its original length. By means of a double-axis laser diameter measuring device, the transition region from a thread longitudinal section b) to a thread longitudinal section a ₂ ) and from here the thread is cut so that 0.5 cm from the thread longitudinal section a ₂ ) remained. On the other side of the thread, the area was determined in which a thread longitudinal section a ₁ ) in the thread longitudinal section b ) passed over. The thread was there at the end of the thread longitudinal section a ₁ ), resulting in a total length of the thread of 30 cm. The area of the thread longitudinal section a ₁ ) took in the stretched state 20 cm and the thread from the longitudinal section b ) in the stretched state 10 cm of the thread piece. In the area of the thread longitudinal section a ₂ ), the diameter of the drawn yarn was 0.30 mm, which is a commercial over-sorting of the starch USP 3 - 0 in monofilaments. In the area of the thread longitudinal section a ₁ ), the diameter was 0.49 mm, this corresponded to a USP 1. The linear tensile strength in the region of the thread longitudinal section a ₁ ), which is later to perform the wound closure, was 72 N with an elongation at break of 42%. The thread was needled with a needle (length 26 mm, needle diameter 0.58 mm, drill channel diameter 0.33 mm, taper-point) by means of a Quicky Tach III needling machine. The needle to thread diameter ratio was 1.18, when the thread diameter of the thread to be used for wound closure longitudinal section a ₁ ) was used. As a comparison thread, a stretched PDO monofilament with a constant over the entire thread length diameter of 0.49 mm with a needle (length 36 mm, needle diameter 0.98 mm, drill channel diameter 0.55 mm, taper-point) was needled. This resulted in a needle-to-thread ratio of 2.0. It should be noted that the needles used were typical needles for thread sizes USP 3-0 and USP 1.

For stitches in the cardiovascular area, the puncture channel bleeding is a major problem. It results from the large, formed by the needle diameter puncture channel, which can not be nearly filled in suture materials on the market by the smaller thread diameter. For the measure of the leakage of a seam, therefore, the ratios of the cross-sectional area of the needle to the cross-sectional area of the thread must be used. In Example 4 according to the invention, this ratio was 1.39, while the comparative example of starch USP 1 had a ratio of 4.0.

Both needled monofilament sutures were subjected to the following test:

A stand-cylinder filled with water was closed with a latex foil, through which the comparative suture was drawn in previously by means of the surgical needle of the invention and in another experiment. The thread according to the invention has been drawn in so far that the thread longitudinal section a ₁ ) was in the area of the puncture channel of the latex foil. Now the cylinder was turned over so that the water column stood on the membrane. The leaked water through the branch channel was collected in a second vessel over a period of 1 minute. While in the thread according to the invention only 2 ml leaked in the observed period, it was 18 ml in the comparison thread. The surgical suture according to the invention thus reduces the extent of the puncture channel bleeding in an efficient manner. In a needling with cutting needles even an even greater difference is to be expected, since the membrane is not only displaced as a "vessel wall", but is cut by means of the cutting of the needle, whereby an effectively larger channel is formed.

Example 5 Surgical suture with unidirectional anchoring structures, formed by cutting into the intermediate thread produced according to Example 1, followed by stripping and subsequent drawing

1. 1. Motorisiert drehbare Fadeneinspannvorrichtung, wobei die Aufnahme an einem Fadenende stationär war und am anderen Fadenende auf einem Schlitten lief und mit einer Gewichtskraft zur Erbringung einer Fadenspannkraft beaufschlagt war.
2. 2. Ein Schneidwiderlager in Form einer Nut, in der der eingespannte Faden unter Spannung geführt wird. Die Nuttiefe betrug ca. 60 % des Fadendurchmessers (40 % des Fadendurchmessers schauten nach oben aus der Nut heraus) und die Nutbreite ca. 120 % des Fadendurchmessers, damit der Faden nach jedem einzelnen Einschnitt frei in der Nut gedreht werden konnte.
3. 3. Die Aufnahme der eigentlichen Schneidvorrichtung, die hinsichtlich des Schnittwinkels im Bereich von 15 ° bis 60 ° einstellbar war.
4. 4. Die Grundplatte der Schneidvorrichtung, die auf einem Schlitten lief und deren Position in Bezug auf die Fadenlängsachse mittels einer Feingewindeschnecke exakt einstellbar war.
5. 5. Die Schneidvorrichtung selbst, die aus einem schnellen Linearmotorhandling (vereinfacht Achse) bestand und an deren unterem Ende ein Klingenhalter mit eingespannter Klinge angebracht war. Die Achse erlaubte eine Genauigkeit der Schnittlänge von 20 µm. Die Anlage umfasste zwei gegensätzlich positionierte Schneidvorrichtungen. Zur Erzeugung eines unidirektionalen Fadens mit Verankerungsstrukturen reichte eine Schneidvorrichtung, zur Herstellung eines bidirektionalen Fadens (die Widerhakenspitze beider Widerhakenteilbereiche schauten zur Fadenmitte hin) wurden beide Schneidvorrichtungen benötigt.
6. 6. Ein Makroskop mit Kamera zur Übertragung des Bildes auf eine Auswertesoftware (Bildbearbeitung) eines angeschlossenen PC's. Das Makroskop diente der Justierung der Schnitttiefe und der Überprüfung des Schnittabstands und des Schnittwinkels.

The intermediate thread of Example 1 was cut to 25 cm so that the middle of the thread longitudinal section a ₁ ) was in the middle of the thread. The incisions for creating the anchoring structures were made on an automated plant with control of the individual process steps, which consisted essentially of the following elements:

1. 1. Motorized rotatable Fadeneinspannvorrichtung, wherein the receptacle was stationary at one end of the thread and ran at the other end of the thread on a carriage and was acted upon by a gravitational force to provide a thread tensioning force.
2. 2. A cutting abutment in the form of a groove in which the clamped thread is guided under tension. The groove depth was about 60% of the thread diameter (40% of the thread diameter looked up out of the groove) and the groove width about 120% of the thread diameter, so that the thread could be rotated freely in the groove after each individual incision.
3. 3. The recording of the actual cutting device, which was adjustable in terms of cutting angle in the range of 15 ° to 60 °.
4. 4. The base plate of the cutting device, which ran on a carriage and whose position with respect to the thread longitudinal axis by means of a fine thread screw was precisely adjustable.
5. 5. The cutting device itself, which consisted of a fast linear motor handling (simplified axis) and at the lower end of a blade holder was mounted with clamped blade. The axis allowed an accuracy of the cut length of 20 microns. The plant included two oppositely positioned cutting devices. To produce a unidirectional thread with anchoring structures, a cutting device was sufficient to make a bi-directional thread (the barb tip of both barb sections looked towards the center of the thread) both cutters were needed.
6. 6. A macroscope with camera for transferring the image to an evaluation software (image processing) of a connected PC. The macroscope was used to adjust the cutting depth and to check the cutting distance and the cutting angle.

After adjusting the cutting angle (here 25 °) and after adjustment of the depth of cut to 20% of the total thread diameter (this thread with a total outer diameter of 1.196 mm and a shell thickness of 0.098 mm, this corresponded to the thread core diameter in the region of the yarn longitudinal section a ₁ ) (d ₁ ) an effective maximum depth of cut of 14%, wherein the depth of cut in the region of the thread longitudinal section b) to 0%, based on the core diameter, decreased, since the shell thickness in the range of thread longitudinal section a ₂ ) was slightly more than 20% of the total diameter and the core in this area was not cut.

1. 1. Anfahren der Mitte des Fadenlängsabschnittes a₁ )
2. 2. Setzen des (ersten) Einschnitts
3. 3. Drehen des Fadenmaterials um 180 ° über seine Längsachse mittels der drehbaren Fadeneinspannvorrichtung
4. 4. Vorschub der Schneidevorrichtung um 0,2 mm (20/100 mm) entlang der Fadenlängsachse
5. 5. Wiederholen der Schritte 2 bis 4 bis zu einer Gesamtschnittzahl von 171 Schnitten (dies überdeckte insgesamt 34 mm des Fadens entlang seiner Längsachse)

To make the thread, the following sequence of process steps was required

1. 1. Approaching the middle of the thread longitudinal section a ₁ )
2. 2. Set the (first) incision
3. 3. Rotate the thread material by 180 ° about its longitudinal axis by means of the rotatable Fadeneinspannvorrichtung
4. 4. Feed the cutting device by 0.2 mm (20/100 mm) along the longitudinal axis of the thread
5. 5. Repeat steps 2 to 4 to a total of 171 Cuts (this covered a total of 34 mm of the thread along its longitudinal axis)

The thread was examined microscopically following the cutting and subsequently peeled off from PCL analogously to Example 2. Subsequently, the incised thread became microscopic in its outer diameter d _a and the effective diameter remaining between the cuts of the opposite rows of cuts d _eff measured. The result is in 12 represented graphically, wherein the ordinate, the diameter in mm and the abscissa, the thread longitudinal position in cm is shown. Out 12 It can be seen that both the outer diameter and the effective diameter in the region of the thread longitudinal section a ₁ ) (to about 2.0 cm from the middle of the thread length section a ₁ ) removed) remained substantially constant, which implies that also the depth of cut in this area remained substantially constant. The situation was different in the area of the thread longitudinal section b ) (Distance from the middle of the Thread longitudinal section a ₁ ) greater than 2.0 cm): Here, the outer diameter decreased linearly while the remaining effective diameter remained constant, indicating that the depth of cut in this region was practically zero, as desired.

In order to set up the anchoring structures and to increase the linear tensile strength of the thread, it was stretched discontinuously as described in Example 4. Due to the cuts, however, only a draw ratio of 3.75 could be used here, since otherwise there would have been a thread break. As described in Example 4, this thread was cut to length so that only the entire, provided with anchoring structures half of the yarn longitudinal section a ₁ ), the thread longitudinal section b) provided with decreasing anchoring structures and about 5 cm of the thread longitudinal section a ₂ ) (without anchoring structures) remained. The total length of the thread was about 20 cm. The linear tensile strength of the yarn was 32 N with a breaking elongation of 29%. The diameter-thick and not provided with anchoring structures area of thread longitudinal section a ₁ ) can serve in threads with unidirectional anchoring structures to produce a loop, for example by ultrasonic welding, by means of which the seam beginning of such a thread can be fixed in the tissue. In the area of the thread longitudinal section a ₂ ), the thread diameter was 0.33 mm (USP 2-0), in the region of the thread longitudinal section a ₁ ) without anchoring structures, the diameter was 0.51 mm (USP 1).

The outside diameter in the regions free of anchoring structures and the effective diameter described above between the rows of anchoring structures, both of which were guided under a diameter, were measured microscopically. The aim was to achieve the effective diameter of the yarn longitudinal section a ₁ ) about the diameter of the thread longitudinal section a ₂ ). Furthermore, the distance between the tips of two adjoining anchoring structures arranged on different rows (ie on the opposite side of the thread surface) was measured. This so-called top-top distance is a measure of the size of the anchoring structures. If the top-top distance approaches that of the diameter (outer diameter or effective diameter), the anchoring structures are only minimally pronounced:

Out 13 It can be seen that the goal, the effective diameter in the areas with anchoring structures approximately at the level of the yarn longitudinal section a ₂ ) (from about 14 cm from the middle of the thread length section a ₁ )), which would not have been the case had one cut into a monofilament of constant diameter throughout. If one had used the same cut configuration with effective depth of cut of 14% in a monofilament with a constant diameter of 1.0 mm, the effective diameter in the area containing anchoring structures would have been about 0.35 mm after drawing, but the diameter would have been The areas without anchoring structures would be approximately 0.52 mm, which in turn would require a larger diameter needle and would result in smaller anchoring forces in the human or animal tissue. By virtue of the smaller effective diameter compared to the rest of the thread area, such conventional anchoring structures are more susceptible to breakage in the area containing anchoring structures.

Examples 6 and 7 Surgical sutures with unidirectional anchoring structures formed by incising into the stripped thread according to Example 2 with subsequent drawing and needling

The stripped thread of Example 2 is cut to 25 cm so that the middle of the thread longitudinal section a ₁ ) was in the middle of the thread. As described in Example 5, two different sectional configurations were produced in the unstretched state: Table 2: Parameterization of the cutting in of Examples 6 and 7 Example 6 Example 7 Cutting angle [°] 25 35 Depth of cut [in% of d ₁ ] 17 12 Cutting distance [mm] 0.20 0.10 average number 171 341 Angular offset [°] or number of rows (in brackets) 180 (2) 180 (2)

The course of the external and effective diameters in the incised but unstretched state of both examples are in the 14a (Example 6) and 14b (Example 7) shown graphically. On the The ordinates are in each case the diameter in mm and the abscissa shows the thread longitudinal position in cm. In essence, those in the show 14a and 14b shown graphics a similar course.

Subsequently, a stretching was carried out analogously to Example 5. The result of the microscopic examination of the drawn threads with anchoring structures is in 15a (Example 6) as well 15b (Example 7) shown graphically, wherein on the ordinates in each case the diameter or the top-top distance in mm and on the abscissa in each case the thread longitudinal position in cm is shown.

In particular, in the range 15 cm from the middle of the thread longitudinal section a ₁ ) removed increase of the diameter d of Example 7 is due to the fact that here only a cutting depth of 12% with respect to the maximum diameter ( d ₁ in the area a ₁ ) and thus only about half of the yarn longitudinal section b) was provided with cuts (the rest of the cuts went into the void as the depth of the blade did not reach down to the decreasing diameter). The difference of the core diameter d ₁ the thread longitudinal section a ₁ ) and d ₂ the thread longitudinal section a ₂ ) in the intermediate or stripped thread should therefore ideally be chosen in such a way that they have a percentage relation to d ₁ twice the intended depth of cut. As in Example 5, the not provided with anchoring structures half of the stretched thread longitudinal section a ₁ ) can be used to make a loop from it, for example by ultrasonic or high frequency welding, which serves as a fixation point in the tissue at the beginning of the seam by the needle is passed through them after the first stitch.

The threads with anchoring structures produced according to Examples 6 and 7 were provided with the following needles at their thin end of the thread longitudinal section a ₂ ) ( d ₂ ~ 0.32 mm): Tab. 3: Needling of Examples 6 and 7 Thread with anchoring structure Example 6 Example 7 Drawing temperature [°] 80 80 draw ratio 3.75 3.75 Linear tensile force [N] 30.9 36.2 Strength with respect to d2 [N / mm ² ] 361 450 Needled thread Example 6a Example 6b Example 7a Example 7b needle radius 0 (linear) 180 0 (linear) 180 Diameter needle [mm] 0.68 0.68 0.68 0.68 Ratio needle thread diameter d1 (without anchoring structure) 1.36 1.36 1.36 1.36 Length needle [cm] 40 26 40 26 Drilling channel diameter [mm] 0.40 40 0.40 40 pinpoint Taper-point Taper-point Taper-point Taper-point

The results of the human or animal tissue anchorability study of the sutures prepared according to Examples 6 and 7 compared to a suture having constant diameter monofilament anchoring structures (Examples 8 and 9) can be found in Examples 8 and 9 below ,

Examples 8 and 9: Comparative Examples to Examples 6 and 7: Threads having anchoring structures of monofilaments of the strengths USP 0 and USP 3-0 without diameter gradient including needling.

Two PDO spun yarns (unstretched) without diameter gradient with the diameters d = 0.98 mm and d = 0.68 mm were cut with the machine described in Example 5 as follows from the middle of the thread and subsequently drawn: Tab. 4: Parameterization during the cutting, drawing and needling of monofilaments with constant diameter (Comparative Examples 8 and 9) Example 8a Example 8b Example 9a Example 9b Diameter of spun yarn [mm] 0.98 0.98 0.68 0.68 Cutting angle [°] 25 25 35 35 Depth of cut [in% of d] 17 17 17 17 Cutting distance [mm] 0.20 0.20 0.07 0.07 Angular offset [°] or number of rows (in brackets) 180 (2) 180 (2) 180 (2) 180 (2) Drawing temperature [°] 80 80 80 80 draw ratio 3.75 3.75 3.75 3.75 Linear tensile force [N] 36.3 36.3 17.3 17.3 Strength in terms of diameter outside barb area [N / mm ² ] 201 201 202 202 Diameter outside barb area [mm] 0.48 0.48 0.33 0.33 Effective diameter in the barb area [mm] 0.26 0.26 0.19 0.19 needle radius 0 (linear) 180 0 (linear) 180 Diameter needle [mm] 0.83 0.78 0.68 0.68 Ratio needle thread diameter (without anchoring structure) 1.73 1.63 2.06 2.06 Length needle [cm] 40 36 40 26 Drill hole diameter 0.55 0.55 0.40 0.40 [Mm] pinpoint Taper-point Taper-point Taper-point Taper-point

The course of the outer and effective diameter of the undrawn according to Example 8, incised thread is graphically in the 16 shown. On the ordinate the diameter is shown in cm and on the abscissa the thread longitudinal position in cm.

After stretching the formed in the 17 shown course of the diameter and the top-top distance, where d is in the region of the anchoring structures for the effective diameter and outside this range for the outer diameter. The Benadelung took place here in the range from 15 cm from the center of the thread and required - in contrast to the inventive examples 6 and 7 - a needle with a significantly larger hole and thus a much larger outer diameter. The non-inventive thread according to Example 8 would have to be classified as USP 1 due to its large outer diameter, but because of its low effective diameter in the anchoring structures, the linear tensile force was only 36 N and thus did not meet the USP limits even taking into account the market discount for self-anchoring sutures , This applies analogously to the thread produced according to Example 9, which represented a suture USP 2-0 due to its outer diameter, but its linear tensile force was almost 2 times lower than the linear tensile force of the threads prepared according to Examples 6 and 7, the also classified as USP 2-0.

Example 10 Investigating the anchoring capacity

In order to examine the anchoring capacity in human and / or animal tissue, which is important for sutures with anchoring structures, for the threads produced according to Examples 6 to 9, an approximately 30 mm thick piece of pork belly without rind was used. For the samples with linear, ie straight needle, the needle was manually from the top of the pork belly to the bottom (way approx. 30 mm) and the thread so far (pulled in the sliding direction of the anchoring structures) that the center of the anchoring area was placed in the tissue. Now, the needle end opposite end of the thread was clamped in the jaws of a universal testing machine from. Zwick and moved at a speed of 80 mm / min in the anchoring direction of the anchoring structures, the maximum anchoring or pull-out force was determined.

For the samples with radial needles, the needle was placed approximately at right angles to the top of the pork belly and pierced through the tissue according to the needle radius so that the needle emerged again at the top of the pork belly. After emergence of the needle, the suture was drawn in so far that the center of the area of the anchoring structures was localized in the tissue. The path or the length of the thread in the tissue corresponded approximately to the needle length. Now, the needle end opposite end of the thread was clamped in the jaws of a universal testing machine from. Zwick and moved at a speed of 80 mm / min in the anchoring direction of the anchoring structures, the maximum anchoring or pull-out force was determined.

As expected, it was found that the radial pull-out force was greater than the linear pull-out force of the thread from the tissue, since in the inner radius of the radial region a more frictional contact between the anchoring structures and the tissue existed. Tab. 5: anchoring forces of the threads with anchoring structures in the pork belly (30 mm thickness) USP Pull-out force linear [N] Pull-out force radial [N] Example 6 2-0 12.7 15.8 Example 7 2-0 10.5 21.7 Example 8 1 8.8 17.9 Example 9 2-0 4.2 8.8

The threads according to the invention with anchoring structures of Examples 6 and 7 showed in comparison to the inventive thread according to Example 9, which was also classified as a thread USP 2-0 strength, increased by at least a factor of 2 anchoring force in the tissue, which was essentially based on it in that their thread diameter in the region outside the anchoring structures substantially corresponded to the remaining effective diameter in the regions with anchoring structures and therefore a thinner needle with a smaller ratio of needle to thread diameter could be selected. Furthermore, the inventive threads according to Examples 6 and 7 with linear tensile forces of 30, 9 N and 36.2 N substantially met the requirements of USP on 2-0 thread size, while the thread not according to the invention a linear tearing force of only 17.3 N showed.

Example 11 Surgical suture with unidirectional anchoring structures formed by cutting into the monocomponent gradient monofilament of Example 3a with subsequent stretching.

The monocomponent monofilament from Example 3a with a maximum thread diameter of 1.10 mm and a minimum thread diameter of 0.93 mm was according to Example 7 (cutting angle 35 °, cutting depth of 12% based on the maximum diameter, cutting distance 0.10 mm) with Provided incisions. Since the yarn longitudinal sections were not as short form as with the bicomponent technology, had here an average of 2000 cuts, starting from the middle of the range of a ₁ ), in order to be able to cut as large a range as possible of b) (decreasing diameter). Due to the sinusoidal diameter profile of the monofilament of Example 3 was obtained in contrast to Example 7 and the 14 b no area with substantially constant depth of cut: Rather, this fell over the almost entire length of the center of a ₁ ) until almost to reach the minimum diameter steadily down to 0%, only the effective diameter remained substantially constant. After stretching analogous to Example 7, a similar picture emerged for the top-top distance: In contrast to Example 7 and the 15 b No area was obtained in which the top-top distance remained essentially the same size. Rather, it dropped steadily over a length of 80 cm, analogous to the depth of cut.

Example 12 Hollow Variable Lumen Filament With Essentially Constant Outside Diameter (Not According to the Invention)

A bicomponent extrusion was carried out analogously to Example 1, except that polypropylene was chosen here as the sheath polymer and polyethylene glycol as the core polymer. The temperature of the spinning head was 190 ° C and the ramp time was varied from 1 s to 20 s, resulting in threads with different lengths of thread sections b ) could be produced. After cutting the undrawn threads spun in this way, the core polymer was dissolved out in a heated water bath (T = 70 ° C.), whereby hollow fibers with tubular structures could be formed, the longitudinal sections b) with gradients with respect to the lumen size and the jacket thickness and longitudinal sections a ₁ ) and a ₂ ) having a substantially constant lumen and constant cladding thickness, wherein the cladding thickness MD2 is in the range of a ₂ ) is greater than the jacket thickness MD1 in the range a ₁ ). The diameter of the lumen is reciprocal to the shell thickness. Instead of the core polymer, a liquid or gaseous component can also be used as support medium with variable mass or volume throughput during the extrusion. The outer diameter of the hollow fibers thus formed is substantially constant. The hollow fibers can be stretched to increase their strength. Hollow filaments with a relatively long ramp time have long longitudinal sections b ) with preferably linearly changing lumen diameter. Such hollow fibers can be used to carry away either wound secretions via capillary effects or to transport fluid additives such as medicaments into the tissue. On a technical level, because of their capillarity, these threads can serve to transport water or other fluid media. In a further embodiment, these hollow body threads in the range of a ₁ ) (lowest cladding thickness) are cut so far that breakthroughs are generated by the cladding in this area. The cuts can be made either in the unstretched or in the stretched state. In this case, anchoring structures can form on the surface of the hollow fibers in addition to the openings. These hollow fibers can serve either as a drainage or as a medicament aid (eg local release of anti-inflammatory drugs or cytostatic drugs), whereby a spatially precisely targeted fixation in the tissue can be achieved by the anchoring structures. In the technical field, such hollow fibers can be used for spraying or atomizing liquids, which are introduced under pressure into the hollow thread. In a further embodiment, these hollow fibers may serve to form alternately turbulent and laminar flows in fluid media which they flow through. This can serve to homogenize dispersions or emulsions. Furthermore, the areas of large lumens can serve as a drug or drug depot, wherein the drug or drug can be embedded for example in a gel.

Claims (15)

Thread having a varying thread diameter, comprising a) first thread longitudinal sections, along which the thread diameter is constant or substantially constant, and b) at least one second thread longitudinal section, along which the thread diameter varies, wherein the first thread longitudinal sections a) are longer than the at least one second Filament longitudinal section b), the thread diameter along the at least one second thread longitudinal section b) varies linearly or substantially linearly, and wherein the thread is a solid thread, characterized in that the thread has a plurality of second thread longitudinal sections b), along which the thread diameter increases or decreases linearly or substantially linearly. Thread after Claim 1 , characterized in that the increase or decrease in the thread diameter along the at least one second thread longitudinal section b) in the unstretched state of the thread an absolute pitch of 20 mm / cm to 0.01 mm / cm, in particular 15 mm / cm to 0.02 mm / cm, preferably 10 mm / cm to 0.02 mm / cm, follows. Thread after Claim 1 or 2 , characterized in that the first thread longitudinal sections a) comprise: a ₁ ) at least one thread longitudinal section, along which the thread continuously has a constant or substantially constant thread diameter d ₁ , and a ₂ ) at least one thread longitudinal section, along which the thread continuously one has constant or substantially constant diameter d ₂ , where d ₁ > d ₂ . Thread according to one of the preceding claims, characterized in that the thread preferably has anchoring structures projecting from the thread surface, in particular in the form of barbs, for anchoring in biological, in particular human and / or animal, tissues. Thread after Claim 4 , characterized in that the anchoring structures on thread longitudinal sections a ₁ ) with a constant or substantially constant thread diameter d ₁ , but not on the thread longitudinal sections a ₂ ) with a constant or substantially constant thread diameter d ₂ , where d ₁ > d ₂ is formed are. Thread according to one of the preceding claims, characterized in that it is the thread around the thread core of a stripped core-sheath thread. A method of producing a thread, in particular according to one of the preceding claims, comprising the following steps: i) coextruding a thread core component and a jacket component from a shaping outlet opening of an extrusion device to form an intermediate thread having a thread core and a sheath surrounding the thread core, and ii) removing of the sheath of the thread core, characterized in that, when performing step i), the mass flow rate of the thread core component and preferably the sheath component varies and / or the intermediate thread is withdrawn after exiting the outlet opening at a varying speed. Method according to Claim 7 , characterized in that for varying the mass flow rate, the speed of a responsible for the extrusion of the yarn core component spinning pump and / or the speed of a responsible for the extrusion of the shell component spinning pump can be varied. Method according to Claim 7 or 8th , characterized in that the sum of the mass flow rates of the yarn core and sheath component is kept constant or substantially constant. Method according to Claim 7 or 8th , characterized in that for varying the withdrawal speed, the rotational speed of a responsible for the withdrawal of the intermediate thread godet is varied. Method according to one of Claims 7 to 10 , characterized in that anchoring structures, preferably in the form of barbs, for anchoring in biological, in particular human and / or animal, tissues are formed by means of cuts in the intermediate thread, wherein the depth of cut is greater than the thickness of the sheath. Method according to one of Claims 7 to 11 , characterized in that anchoring structures, preferably in the form of barbs, for anchoring in biological, in particular human and / or animal, tissues are formed by means of incisions in the stripped thread core. Thread with a varying thread diameter, in particular produced or producible by a method according to one of Claims 7 to 12 , characterized in that the thread is a thread core of a stripped core-sheath thread. Medical product, preferably surgical suture, comprising at least one thread according to one of Claims 1 to 6 or at least one thread after Claim 13 , Medical kit, in particular in the form of a needle-thread combination, comprising at least one surgical needle and at least one thread according to one of Claims 1 to 6 , at least one thread behind Claim 13 or a medical product Claim 14 ,

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