EP3669022B1 - Musical string - Google Patents

Description

The present invention relates to a musical instrument string and a sports racquet string and a method of manufacturing the same.

The string can also be used as a line for a fishing rod or as a material for a fishing gear, in particular a fishing net.

Traditionally manufactured natural gut strings with a core made of natural gut have excellent playing characteristics, in particular high energy efficiency in impulse excitation and impulse transmission, which among other things leads to an easy, fast and precise response. The natural gut string core is a bundle of twisted and chemically cross-linked gut strips that together form a strand of exceptional strength, flexibility, and resilience. However, strings with a natural gut core also have a number of serious disadvantages. These include the high sensitivity to temperature and humidity fluctuations, which lead to low load and tuning stability. Furthermore, due to the unavoidably high property tolerances in natural products, there are large quality fluctuations in products that are actually the same. Strings with a core made of natural gut therefore only meet the requirements of today's concerts and sporting competitions to a limited extent.

Alternatively, strings with a core made of polymer fibers are known, e.g US2,226,529 made of polyamide or in GB2303730A made of PEEK. For strings of bowed instruments, the string core, such as in AT169306 , AT309188 or EP2 099 022 A1 described, usually made of fiber bundles or multifilament yarns. As in AT169306 , AT309188 or EP2099022 mentioned above, a specified number of multifilament yarns are bundled for the core and - comparable to natural gut - usually twisted in during the production of the string core. However, there is no chemical crosslinking, ie the filaments are always without significant destruction separable. The internal damping and thus the sound of the strings can be influenced by the predeterminable number of synthetic polymer fibers and the twisting of these, which makes them particularly suitable for bowed strings.

However, this loose connection of the plastic fibers in the core of the string leads to a relative movement of the fibers to one another when the string is subjected to stress and vibration, which leads to internal friction and thus energy losses. The relative movement of the fibers under load also causes mechanical wear on the fiber surfaces, which reduces the lifespan of the strings, especially in terms of sound, due to the changing acoustic coupling and damping. Compared to strings made of natural gut, the main disadvantages of these strings are therefore higher energy losses during excitation and impulse transmission, a poorer response or slower reaction to excitation and a shorter service life.

Alternatively, for example, from U.S. 2,641,949 and EP 2 131 352 A1 Strings with a core made of steel cable are known. These strings have an extraordinarily high load and tuning stability. Strings with such a core show the same relative movement of the individual wires to one another, which again leads to internal friction and thus energy losses. Musical strings with a core made of fine steel wires, carbon and/or silicon carbide fibers are known to solve this problem, with the wires of the core being embedded in an elastomer or a ductile metal. A disadvantage of such musical strings is that, in comparison to strings with a core made of natural gut or polymer fibers, they can only be excited by applying a comparatively high bow pressure and are therefore only conditionally suitable for making music with different dynamics and/or timbres. Such musical strings also have the disadvantage that they react poorly to a change of bow, so that these musical strings are perceived by the musician as slow and braking, and with such musical strings it is only possible to a limited extent to cleanly intonate fast runs or bow changes in spiccato and to play.

the US5,601,762 describes strings for musical instruments, sports equipment or fishing, which have a composite core made of a plurality of polymer threads which are connected with a binding resin. According to the example 2 the US5,601,762 the string thus formed is coated with another resin. For further Treating the strings beats the US5,601,762 before undergoing treatment with radioactive radiation.

the U.S. 4,016,714 describes strings for racquets and musical instruments comprising a composite core of a plurality of thermoplastic filaments twisted together, bonded with a first cationic wetting agent and finally bonded with a thermoplastic binder resin.

From the JPH 07150434 A a string with a core made of a thermoplastic is known, which is covered with many thin threads made of vinyl fluoride, which in turn are likely to be covered with a resin. the JPH 03205070 A in turn describes a string with a composite rope core, which is stranded from individual composite elements. Each of the composite elements consists of aramid fibers fused together with nylon fibers. The composites are then twisted and wound with additional aramid and nylon fibers, which are embedded in a nylon resin that forms the surface of the string.

From the AT504 015 B1 or. US8,283,538 B2 a musical string with at least one composite core is known, in which the at least one composite core comprises a first core element and a second core element, the first core element and the second core element comprising at least one organic material, and the first core element and the second core element being connected at least in regions by means of of an intervening and/or enveloping first polymer element, characterized in that when the musical string is tensioned with a predeterminable tuning weight, the first polymer element is essentially tension-free. In all of the embodiments described, the string elements are constructed from different materials. The actual core material is distinguished here from a connecting polymer. US3645819 discloses a musical instrument string composed of fused fibers having a core-sheath structure.

The disadvantage of all of these proposed solutions is a relatively high level of energy damping or acoustic damping of the string constructions due to the many materials combined with one another, specifically polymers and binders. In particular, the numerous phase transitions from material to material that can be found in all the proposed solutions lead to high energy losses of the applied impulse and thus to poorer playing technique and tonal response.

The present invention is therefore based on the object of providing a musical instrument or sports racket string with high stability and consistency in terms of strength, elasticity and flexibility, which is characterized in particular by lower energy losses during excitation and impulse transmission as well as a longer service life.

According to the invention, this object is achieved by a musical instrument string or sports racket string according to claim 1. A materially bonded connection is to be understood in particular as a connection of the thermoplastic fibers that cannot be detached without damage or even destruction. It should be noted that the term "string core" is also used here when the string core or string does not have a covering.

Furthermore, this object is achieved by a method for production according to claim 11.

Advantageously, the bundle of thermoplastic fibers forms a self-bonded flexible strand.

In a particular embodiment, the string core can comprise a plurality of said bundles of thermoplastic fibers, with the bundles of thermoplastic fibers forming a plurality of flexible strands that are each bound in themselves.

According to the invention, the thermoplastic fibers are highly stretched. This manifests itself in the fact that the macromolecules of the fibers show an orientation and orientation along the fiber axis. In addition to the amorphous phase, they also contain crystalline areas. The fibers are at least partially crystalline.

According to the invention, the elongation of the thermoplastic fibers at room temperature and maximum tensile load is less than 20% and the elongation at break of the thermoplastic fibers is less than 25%.

The thermoplastic fibers of the bundle or at least one of the bundles are expediently twisted or twisted around one another.

According to the invention, at least some of the thermoplastic fibers have a core-sheath structure.

In particular, it can be provided that the fiber core of the core-sheath structure comprises or consists of a first thermoplastic material and the fiber sheath of the core-sheath structure comprises a second thermoplastic material.

In particular, it can be provided that the fiber sheath volume proportion of the core-sheath structure is less than 60% by volume, more preferably less than 30% by volume and particularly preferably less than 20% by volume.

According to the invention, the fiber sheath also contains ferromagnetic and/or ferrimagnetic particles, in particular solid particles.

The particles advantageously have a primary particle diameter of less than 500 nm.

In a particular embodiment, the first thermoplastic material and the second thermoplastic material are identical. However, the first thermoplastic material and the second thermoplastic material can also be different.

The thermoplastic fibers expediently comprise or consist of polyaryletherketone, PAEK, preferably polyetheretherketone, PEEK, and/or polyamide, PA, and/or polyimide, PI, and/or polyphenylene sulfide, PPS, and/or polyvinylidene fluoride, PVDF.

Advantageously, the string has at least one covering, preferably made of at least one plastic or at least one metal, which is arranged or wound around the core of the string, preferably helically.

According to the invention, the method comprises the continuous or batchwise feeding of a bundle of thermoplastic fibers while simultaneously heating the same in continuous or batchwise flow or past a magnetic induction device or the same.

In particular, it can be provided that thermoplastic fibers without a fiber sheath are also at least partially melted on the surface by heating the fiber sheaths of surrounding thermoplastic fibers with a core-sheath structure and fused with the same in the contact areas and bonded to one another.

The tension of the thermoplastic fibers is advantageously adjusted as they pass through or past the induction heating device. In the case of cut strings, this can be done, for example, by a mechanical tension weight, by spring force or mechanical roller resistance at one or both string ends or by the tension hooks holding the string, which tighten or stretch the fiber bundle to the desired extent. In the case of endless fibers, this can be done, for example, by different speeds of the godets/rollers transporting the fibers or by mass or spring-loaded tension rollers.

The thermoplastic fibers are expediently twisted together before they are fused.

According to a further particular embodiment of the present invention, the string core is formed from a plurality of said bundles, each forming a strand, preferably in a twisted form.

In addition, it can be provided that the surface of the string core is mechanically ground and/or polished.

According to a further particular embodiment of the present invention, the string core is provided with a first covering, preferably made of a preferably round or flat wire or of a polymeric monofilament, wound around the string core, preferably helically.

Finally, it can be provided that the string core is provided with at least one additional covering, preferably made of a particularly round or flat wire or of a polymeric monofilament, preferably wound in parallel or crossed helically around the first covering.

The present invention is based on the surprising finding that the innovative, direct and material connection of the thermoplastic fibers of the string core reduces or even prevents energy loss in the string core through friction of loosely connected individual fibers when the string is loaded and moved, and at the same time the strength, elasticity and flexibility of the string core is improved. Furthermore, there are no binders, resins or intermediate polymers used in the prior art, which avoids numerous phase transitions from material to material, which lead to high energy losses of the applied impulse and thus to poorer playing and tonal response.

Strings with such a new type of string core show an extraordinarily high level of stability and consistency in terms of strength, elasticity and flexibility. In particular, the strings have high load and tuning stability, a particularly easy and quick response even with quick bow changes and in spiccato even with the lightest bow pressure.

At least in one particular embodiment, a string, in particular for bowed and/or plucked instruments, but also sports equipment, comprising a core (string core) and optionally at least a first covering, which is arranged around the string core, is used to achieve a load or Suggested tuning stability, quick response and - for musical strings - a clean, singing sound, that the core comprises a predeterminable multiplicity of multi-component thermoplastic fibers which are at least partially cohesively connected to one another by the formation of local melting zones in the interface region of the thermoplastic fibers and therefore cannot be separated from one another without being destroyed.

A string can be realized which has a particularly light, fast and precise response comparable to the strings with a natural gut, but without their particularly disadvantageous sensitivity to fluctuations in humidity and temperature.

At least in one special embodiment, the musical instrument string has a clean, richly colored and singing sound even with the slightest excitation. Combined with a large dynamic spectrum, it expands a musician's artistic possibilities of expression.

Due to the low tuning tension that is possible due to the design, the musical instrument strings are also recommended for baroque or medieval stringed instruments. In particular, strings made with the novel string core can also be used without additional winding, i.e. with a bare core, both as musical instrument strings and also as sports racket strings, since the core forms a solid, bound strand, at least in one special embodiment. In the case of musical instrument strings, strings with this new type of bare core are recommended, for example, for use as violin E and A or viola A and D strings, which historically were also used as non-spanning gut strings. In the sense of a finished musical instrument string, these strings still lack the surface optimization with, for example, a longitudinal grind, the colored threading at the ends and the suspension, for example ball. The core of the string can also be formed from more than one of the individual strands that are bonded to one another, for example from three, five or more such strands. The strands can be twisted together in a specified number. For example, this multi-strand string core can be used with the loosely twisted strands or additionally heated locally in a magnetic field and thus made even more compact.

• Figur 1 eine Querschnittsansicht von einer einzelnen Thermoplastfaser mit einer Kern-Mantel- Struktur des Saitenkerns einer Saite (Musikinstrumentensaite oder Sportschlägersaite) gemäß einer besonderen Ausführungsform der vorliegenden Erfindung;
• Figur 2 eine Querschnittsansicht von einem Bündel von Thermoplastfasern mit Kern-Mantel-Struktur des Saitenkerns einer Saite (Musikinstrumentensaite oder Sportschlägersaite) gemäß einer weiteren besonderen Ausführungsform der vorliegenden Erfindung in einem Vorproduktstadium;
• Figur 3 eine Querschnittsansicht von einem Bündel von Thermoplastfasern mit Kern-Mantel-Struktur des Saitenkerns einer Saite (Musikinstrumentensaite oder Sportschlägersaite) gemäß einer weiteren besonderen Ausführungsform der vorliegenden Erfindung nach Erwärmung und Zusammenschmelzen der einzelnen Thermoplastfasern zumindest teilweise entlang den Grenzflächen;
• Figur 4 eine Querschnittsansicht durch mehrere Bündel (mehrere Einzelstränge, im vorliegenden Fall sieben) von Thermoplastfasern von Figur 3.
• Figur 5 eine Querschnittsansicht durch mehrere Bündel (mehrere Einzelstränge, im vorliegenden Fall neunzehn) von Thermoplastfasern von Figur 3.
• Figur 6 eine Querschnittsansicht von einer Vielzahl von Thermoplastfasern mit und ohne Kern-Mantel-Struktur des Saitenkerns einer Saite (Musikinstrumentensaite oder Sportschlägersaite) gemäß einer besonderen Ausführungsform der vorliegenden Erfindung in einem Vorproduktstadium;
• Figur 7 eine Querschnittsansicht eines Saitenkerns aus mehreren Thermoplastfasern mit und ohne Kern-Mantel-Struktur und Fasern, bestehend aus einem weiteren Werkstoff, einer Saite (Musikinstrumentensaite oder Sportschlägersaite) gemäß einer weiteren besonderen Ausführungsform der vorliegenden Erfindung in einem Vorproduktstadium; und
• Figur 8 eine Teillängsschnittansicht von einer Musikinstrumentensaite gemäß einer besonderen Ausführungsform der vorliegenden Erfindung.

Further features and advantages of the invention result from the appended claims and from the following description, in which the schematic drawings several embodiments of the invention are explained. while showing

• figure 1 a cross-sectional view of a single thermoplastic fiber with a core-sheath structure of the string core of a string (musical instrument string or sports racquet string) according to a particular embodiment of the present invention;
• figure 2 a cross-sectional view of a bundle of thermoplastic fibers with a core-sheath structure of the string core of a string (musical instrument string or sports racquet string) according to a further particular embodiment of the present invention in a preliminary product stage;
• figure 3 a cross-sectional view of a bundle of thermoplastic fibers with a core-sheath structure of the core of a string (musical instrument string or sports racquet string) according to another particular embodiment of the present invention after heating and fusing the individual thermoplastic fibers at least partially along the interfaces;
• figure 4 a cross-sectional view through several bundles (several individual strands, seven in this case) of thermoplastic fibers from figure 3 .
• figure 5 a cross-sectional view through several bundles (several individual strands, nineteen in this case) of thermoplastic fibers from figure 3 .
• figure 6 a cross-sectional view of a plurality of thermoplastic fibers with and without a core-sheath structure of the string core of a string (musical instrument string or sports racquet string) according to a particular embodiment of the present invention in a preliminary product stage;
• figure 7 a cross-sectional view of a string core made of several thermoplastic fibers with and without core-sheath structure and fibers, consisting of another material, a string (musical instrument string or sports racquet string) according to a another particular embodiment of the present invention in a precursor stage; and
• figure 8 12 is a partial longitudinal sectional view of a musical instrument string according to a particular embodiment of the present invention.

The one in the figure 1 In this example, the thermoplastic fiber 10 shown has a circular cross section and a core-sheath structure, with the fiber core 12 consisting of a first thermoplastic material and the fiber sheath 14 consisting of a second thermoplastic material and ferromagnetic particles embedded therein, only some of which are indicated by reference numeral 16. In this example, the ferromagnetic particles are distributed evenly only in the fiber cladding.

the figure 2 shows a string core 18 in the making from a plurality of thermoplastic fibers 10, as shown in FIG figure 1 is shown. The thermoplastic fibers 10 are in the in figure 2 shown stage not yet connected. In the figure 3 are those in the figure 2 shown thermoplastic fibers 10 in the longitudinal direction at least partially melted together at the interfaces 20. Fusing can be done, for example, by passing through a magnetic induction device (not shown). The ferromagnetic particles 16 only heat the fiber sheath 14 as it passes through the induction device and at least partially melts it and connects it to directly adjacent thermoplastic fibers in a materially bonded manner. The thermoplastic fibers form a bundle 22. The high mechanical strength properties of the fiber core achieved in the stretching process are retained due to the exclusive heating of the fiber sheath.

In the figure 4 a string core 18 of a string in the process of being formed is shown. This consists of several bundles 22 according to figure 3 and each of the bundles 22 forms a self-contained flexible strand. While the string core 18 in the figure 4 is composed of seven bundles 22 or strands, there is the string core 18 of figure 5 even from nineteen such bundles 22.

figure 6 shows a string core 18 of a string that is in the process of being formed. This includes both thermoplastic fibers 10 with a core-sheath structure and thermoplastic fibers 11 without the same.

At the in the figure 7 The variant shown includes the string core 18 of a string thermoplastic fibers 10 with a core-sheath structure and thermoplastic fibers 11 without a core-sheath structure and fibers 24, which consist of another material, such as a metal, glass or a non-thermoplastic material.

Finally shows the figure 8 a musical instrument string 26 having a string core 18, the composition of which is not shown in detail, and a first covering 28, an outer second covering 30 surrounding the first covering 28 and an outer third covering 32 surrounding the second covering 30. The first covering 28 and the The second sheath 30 each consists of a braiding of metallic round wire or polymer monofilament, while the third sheath 32 consists of a braiding of metallic flat wire or a polymer tape.

The features of the invention disclosed in the above description, in the drawings and in the claims can be essential both individually and in any combination for the realization of the invention in its various embodiments. The invention is defined by the claims.

Reference List

10

thermoplastic fiber

11

thermoplastic fiber

12

fiber core

14

coat

16

particles

18

string core

20

interfaces

22

bunch

24

fibers

26

musical instrument string

28

first serving

30

second serving

32

third serving

Claims (18)

1. Musical instrument string (26) or sports racket string, comprising a string core (18) which comprises or is composed of a bundle (22) of highly oriented thermoplastic fibres (10), wherein the elongation of the thermoplastic fibres (10) at room temperature and at maximum tensile loading is less than 20%, and the elongation at break of the thermoplastic fibres (10) is less than 25%, wherein at least part of the thermoplastic fibres (10) has a core/casing structure, wherein at least some thermoplastic fibres (10) of the bundle (22) are connected to one another in a materially integral manner at least in part, such as for example in a punctiform or linear manner, by fusing on the boundary surfaces (20) of the fibre casings (14) of the core/casing structure, characterized in that the fibre casing (14) additionally contains ferromagnetic and/or ferrimagnetic particles (16), in particular solid matter particles.
2. String according to Claim 1, wherein the bundle (22) of thermoplastic fibres (10) forms an inherently bonded flexible strand.
3. String according to Claim 2, wherein the string core (18) comprises a plurality of said bundles (22) of thermoplastic fibres (10), wherein the bundles of thermoplastic fibres form a plurality of in each case inherently bonded flexible strands.
4. String according to one of the preceding claims, wherein the thermoplastic fibres (10) of the bundle (22) or of at least one of the bundles are twisted in single-ply or two-ply form.
5. String according to one of the preceding claims, wherein the fibre core (12) of the core/casing structure comprises or is composed of a first thermoplastic material, and the fibre casing (14) of the core/casing structure comprises a second thermoplastic material.
6. String according to one of the preceding claims, wherein the volumetric proportion of the fibre casing of the core/casing structure is less than 60% by volume, preferably less than 30% by volume, and particularly preferably less than 20% by volume.
7. String according to Claim 5 or 6, wherein the particles (16) have a primary particle diameter which is less than 500 nm.
8. String according to one of Claims 5 - 7, wherein the first thermoplastic material and the second thermoplastic material are identical.
9. String according to one of the preceding claims, wherein the thermoplastic fibres (10) comprise or are composed of polyaryletherketone (PAEK), preferably polyetheretherketone (PEEK), and/or polyamide (PA), and/or polyimide (PI), and/or polyphenylene sulfide (PPS), and/or polyvinylidene fluoride (PVDF).
10. String according to one of the preceding claims, wherein said string has at least one sheathing (28), preferably composed of at least one plastics material or at least one metal, said sheathing (28) preferably being disposed or wound helically about the string core (18).
11. Method for producing a string according to one of the preceding claims, comprising the continuous or batch-wise feeding of a bundle (22) of thermoplastic fibres (10) while simultaneously heating said bundle (22) of thermoplastic fibres (10) continuously or in batches when running through or along a magnetic induction installation so that, in the case of thermoplastic fibres (10) having a core/casing structure, only the fibre casing (14) of the core/casing structure is heated and at least slightly fused on account of the inductive heating by means of the ferromagnetic and/or ferrimagnetic particles, wherein at least some thermoplastic fibres (10) of the bundle (22) are connected to one another in a materially integral manner at least in part, such as for example in a punctiform or linear manner, by fusing on the boundary surfaces (20) of the fibre casings (4).
12. Method according to Claim 11, wherein thermoplastic fibres (11) without a core/casing structure are, due to the heating of the fibre casings of surrounding thermoplastic fibres (10) having the core/casing structure, likewise at least partially slightly fused on the surface and fused and connected in a materially integral manner to the latter in the contact faces.
13. Method according to one of Claims 11 - 12, wherein the tension of the thermoplastic fibres (10) is set when the latter run through or along the induction heating installation.
14. Method according to one of Claims 11 - 13, wherein the thermoplastic fibres (10) are conjointly twisted prior to fusing.
15. Method according to one of Claims 11 - 14, wherein the string core (18) is formed from a plurality of said bundles (22), preferably in a twisted form, that form in each case one strand.
16. Method according to one of Claims 11 - 15, wherein the surface of the string core (18) is sanded and/or polished in a mechanical manner.
17. Method according to one of Claims 11 - 16, wherein the string core (18) is provided with a first sheathing (28) which is preferably helically wound about the string core and which is preferably composed of a preferably round or flat wire, or of a polymer monofilament.
18. Method according to Claim 17, wherein the string core (18) is provided with at least one further sheathing (30, 32) which is preferably helically wound so as to be parallel or crossed about the first sheathing and which is preferably composed of an in particular round or flat wire, or of a polymer monofilament.

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