DE102009046200A1 - Thread sealant made of different multifilament yarns - Google Patents

Abstract

The present invention relates to a thread sealant, comprising at least two multifilament yarns which differ in the chemical identity of their filament polymers. Further objects of the invention are a dispenser for the thread sealant, a method for producing the thread sealant and its use for sealing screwed pipe connections, and the use of an arrangement of at least two multifilament yarns, which differ in the chemical identity of their filamentary polymers, as thread sealants.

Description

The present invention relates to a thread sealant comprising at least two multifilament yarns, a dispenser for such a thread sealant, a method for producing the thread sealant and the use of a thread sealant according to the invention for sealing screwed pipe joints.

The sealing of bolted connections is an important prerequisite for the efficient functioning of, for example, machines, installations and piping systems in many fields of trade and industry. Accordingly, a number of systems are known in the prior art which meet the complex requirements for such sealants more or less adequately. For example, a two-component system of hemp fiber and paste is common. Dry hemp fiber is partly provided in loose non-woven form. In addition, hemp is also available in the form of a wound on a coil strand, which may be contained in a dispenser with a tubular discharge guide. In both cases, the required length of hemp is drawn out and wrapped around the threaded zone of a pipe joint inner. The paste may first be applied to the connector such that the hemp is pulled through the paste as the connector is wrapped. Alternatively or additionally, the paste is applied over the hemp. For example, although such a two-component system is widely used, it can not be used for pipes carrying potable water because hemp as a microbiological growth-promoting substance does not meet the standards for materials in contact with drinking water.

In addition, an alternative two-component system is available that includes polypropylene fiber instead of hemp and is also approved for contact with drinking water. Nevertheless, even such a two-component system has disadvantages. So it is cumbersome to use, requires a high degree of skill and takes a relatively long time for the application.

Another commercially available sealing material is a non-fibrous polytetrafluoroethylene (PTFE) tape. It is typically about 10 mm wide and 0.25 to 0.5 mm thick. In use, the tape is wrapped around the threaded zone of a threaded connector outer. If a certain thickness to be built, a corresponding number of overlays can be created. However, this system also requires considerable skill in the application and also can not be used for a connection that should allow readjustment without loss of seal.

EP 0 975 545 B1 describes a system for sealing Rohrschraubverbindungen based on a Multifilgarns, which is finished with a compound sealant and packaged in a dispenser from which it can be applied directly to the threaded zone of a pipe. Such sealants often contain silicone oil in the sealant and are then not approved for use in paint shops and automotive factories. In addition, it may come in contact with solvents, gasoline or diesel to wash out the paste and thus affect the sealing effect. Further limitations result from incompatibilities of the paste to some plastics and temperature limits.

There is therefore a need for universally applicable thread sealants whose effectiveness is largely independent of the conditions of use. The object of the present invention is therefore to provide a thread sealant which is subject to as few restrictions as possible in use, in particular is stable to solvents and temperature fluctuations, can be applied easily and permits subsequent adjustment of the threaded connection without loss of sealing effect. The object is solved by the subject of the main claim of the present invention.

A first subject of the invention is therefore a thread sealant comprising at least two multifilament yarns A and B, each containing at least two filaments constructed of filament polymers, wherein at least one filament of the multifilament A of at least one filament of the multifilament yarn B in the chemical identity of at least one Filament polymer distinguishes.

Such a thread sealant can be applied in a simple and clean manner, is subject to no restrictions on an application in which solvents are used, and shows a good sealing effect even with greater temperature fluctuations. In addition, it allows adjustment in the assembly of piping components such as fittings and valves and allows turning back the threaded connection to the desired position without loss of sealing effect.

A sealant is understood to mean an elastic material which is used for sealing components or connections between components against water, atmospheric influence or aggressive media.

A multifilament yarn is understood to mean a twisted yarn consisting of a constant number of fibers (filaments). The multifilament yarn is therefore in a cylindrical, elongated form, for example as a single strand, and thus differs from a woven, flow or gauze. Multifilament yarn suitable in accordance with the present invention is sufficient and flexible to wrap around the threaded portion of the pipe, but also strong enough to withstand the winding operation about the threads of the externally threaded component and the threading of the internally threaded component which can cut and cut into unsuitable yarn , One of the primary functions of the sealant is to act as a plug in the threaded connection and to provide mechanical strength to the threaded assembly. It is exposed to predominantly static stresses and must cause such a large friction between the connected parts that the threaded connection does not dissolve even under high static stress, for example in the case of overpressure. Nevertheless, it should be possible to partially and possibly completely loosen the screw connection produced again.

A multifilament yarn which can be used in accordance with the invention may have the property of absorbing water, which may cause the material in the threaded connection to swell and produce a better seal.

Preferably, the thread sealant according to the invention contains exclusively multifilament yarns whose raw material is non-toxic in the sense that it is permissible for applications with food contact, in particular drinking water contact.

A multifilament yarn which can be used according to the invention can be spun in a suitable manner or can comprise woven and / or felted filaments or threads. It is preferably in a form comparable to twine or twine. The multifilament yarn can be in the "dtex" range of 500 to 5,000, which corresponds to 500 g to 5,000 g of weight per 10,000 meters of yarn. The decitex or "dtex" is the metric unit for fiber diameter and is expressed as weight in g per 10,000 m filament. For heavier material, for example 2,100 dtex, a smaller number of turns on the pipe thread are required to effect a seal compared to lighter material, for example, 970 dtex. A multifilament yarn which can be used according to the invention preferably lies in the "dtex" range of 900 to 2,500.

It is assumed in the context of the present invention that the filaments of a multifilament yarn which can be used according to the invention consist of polymers which are referred to herein as filament polymers. The multifilament yarns or the individual filaments can basically consist of natural and / or synthetic polymer fibers. The fibers are preferably synthetic, ie polymers produced by chemical-technical means.

By a filament polymer is meant any polymer which contributes to the construction of at least one fiber of the multifilament yarn. By "different in chemical identity" is meant that the respective filament polymers differ in chemical structure from at least 50% of the total amount of the respective polymer forming monomer molecules. Preferably, the polymers in question in the chemical structure of at least 60%, more preferably of at least 70%, in particular of at least 80%, for example of at least 90% and most preferably of at least 99% of the total amount of the respective polymer forming monomer molecules.

Due to the different chemical identity of the respective multifilament yarn forming polymers, a highly effective sealing of a bolted connection in the static state is achieved. In addition, the bolted connection can be easily solved again, without causing damage to the thread by tilting or other mechanical stress.

Preferably, at least one of the filament polymers of the multifilament yarns A and / or B is a fluorine-containing polymer. Such a fluorine-containing polymer may be perfluorinated or even partially fluorinated. Suitable examples are polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), copolymers of tetrafluoroethylene and hexafluoropropene, copolymers of tetrafluoroethylene and perfluorovinylalkyl esters, for example perfluoropropylvinylether (PFA) and perfluoroethylvinylethers, and fluorinated olefinic interpolymers comprising the monomers listed above and optionally other tetrafluoroethylene-based copolymers , At least one of the filament polymers of the multifilament yarns A and / or B is particularly preferably PTFE or PVDF.

In a preferred embodiment of the present invention, the thread sealant comprises at least one further multifilament yarn C containing at least two filaments composed of filamentary polymers, wherein at least one of the filamentary polymers of the multifilament yarn C belongs to the same class of polymer as at least one of the filamentary polymers of the multifilament yarns A and / or B. By "the same class of polymers" is meant that the polymers in question can be assigned to a certain class of polymer according to the characteristic groups which connect individual segments of the polymer chains, for example and preferably one of the classes of polyesters, polyethers, polyamides, polyimides, polyureas, polyurethanes and / or polysulfides. The filament polymers belonging in each case to identical polymer classes are particularly preferably polyamides. A multifilament yarn C may differ from the multifilament yarns A and / or B to varying degrees, but in the limiting case may also be identical to one of the multifilament yarns A or B. Moreover, it is also possible according to the invention that the thread sealant contains only the two multifilament yarns A and B, which differ in at least one filament polymer, but also each have one or more identical filament polymer (s).

The proportion by weight of identical polymer classes belonging to filament polymers is preferably 30 to 70 wt .-%, based on the total weight of the thread sealant.

Within the scope of a further preferred embodiment of the thread sealant according to the invention, the filament polymers of the multifilament yarns used each comprise at least one polymer selected from polyamides, polyolefins, polyethylene terephthalate (PET), phenolic resins and fluorine-containing polymers.

A polyamide is understood as meaning a synthetic polymer which contains a plurality of amide bonds -NH-CO- in the main chain. Particular preference is given to using nylon (PA 66). By a polyolefin is meant a polymer which can be obtained by polymerization of an alkene. Of the polyolefins, polyethylene and polypropylene are preferably used. PET can be used in any conventional modification, especially as a blend with other polymers such as polycarbonates or polybutylene terephthalates. By phenolic resins are meant synthetic resins which can be prepared by condensation of phenols with aldehydes or by addition of phenols to unsaturated compounds and optionally derivatization of the respective products. For fluorine-containing polymers, the above statements apply. Most preferably, the filament polymers of the multifilament yarns used in the invention each comprise at least one polymer selected from polyamides and fluorine-containing polymers. In particular, the filament polymers of the multifilament yarns used contain polyamides and polyvinylidene fluorides.

Preferably, at least one of the multifilament yarns A and B of the thread sealant according to the invention has an elongation at break which is at least 10%, preferably at least 20%, in particular at least 50%, compared with the elongation at break of at least one other multifilament yarn determined by identical methods under identical conditions is increased by at least 100% and more preferably by at least 120%. The elongation at break is understood to be the ratio of the length change achieved in the material tear to the initial length. The percentages here are based on the initial length of the multifilament yarn and not on the elongation at break of the respective other multifilament yarn. For example, a 15% increase in the elongation at break of one multifilament yarn over another multifilament yarn expresses that the stronger multifilament yarn can be stretched 15% of this initial length from a fixed initial length than the less solid multifilament yarn before a material tear occurs. Preferably, the elongation at break is after ISO 527 certainly.

The thread sealant of the invention thus preferably comprises a stronger multifilament yarn and a less strong multifilament yarn. Such a combination allows a particularly balanced relationship between strength of the sealant and sliding properties, as they are particularly desirable when adjusting threaded connections.

The sealant according to the invention can be used in an uncomplicated manner. The thread sealant according to the invention preferably consists essentially of multifilament yarns. This is understood to mean that multifilament yarns contain at least 90% by weight, preferably at least 95% by weight, in particular at least 97% by weight, for example at least 98% by weight and very particularly preferably at least 99% by weight. % form the thread sealant according to the invention. This can therefore be easily and cleanly in the apply the desired amount. A thread sealant according to the invention is preferably ready to use, and therefore does not require any activities to be carried out by the consumer in order to arrive at an applicable product. In particular, no joining of whatever type of components and / or parts by the consumer is necessary in order to have the thread sealing agent according to the invention ready for application.

The order of the thread sealant according to the invention, for example, and preferably directly from a dispenser. A further subject of the present invention is therefore a dispenser which contains a thread sealant according to the invention and which comprises a hollow body, a cover part with a dispensing opening and a closure device for closing the dispensing opening, wherein the ready-to-use thread sealant is contained in the hollow body. The hollow body preferably contains a spool which contains a base resting on the inner bottom of the hollow body and a spindle onto which the thread sealing means according to the invention is spirally wound, so that it can be removed as required. Alternatively, the dispenser does not include a spindle, but the thread sealant is wound within the hollow body using a winding technique and may be unwound from an axial passage formed when the sealant is deposited into the body. In this case, preferably hollow body and closure are two complementary cylindrical parts which are interconnected by an internal screw thread located on the closure and by an external screw thread located on the hollow body.

In a further preferred embodiment of the present invention, the thread sealant is substantially free of sealing paste. A sealing paste is understood at the time of application of the thread sealant liquid to viscous, suitable as a sealant material or as a coating applied to the multifilament yarn material, especially oil-natural resin mixtures, compositions of oils and filler particles, often natural oils such as linseed oil or synthetic oils such as silicone oils or mineral oils are used. Further, the term also includes curable compositions containing, for example, reactive monomers or prepolymers. "Essentially free of sealing paste" means that sealing paste to a maximum of 0.5 wt .-%, preferably 0.3 wt .-%, in particular 0.2 wt .-% and particularly preferably 0.1 wt .-%, based on the total weight of the thread sealant is contained in the thread sealant according to the invention. Most preferably, the thread sealant according to the invention contains no or at least no analytically detectable amounts of sealing paste.

Another object of the present invention is a method for producing a thread sealant according to the invention, which is characterized in that at least two multifilament yarns A and B, each containing at least two filaments composed of filament polymers, wherein at least one filament of the multifilament A of at least one filament of the multifilament yarn B differs in the chemical identity of at least one filament polymer, are mechanically bonded together. The joining of the multifilament yarns comprises any mechanical process which leads to a coherent composite of the multifilament yarns, for example entanglement of the multifilament yarns in one another or compression with compressed air.

Another object of the present invention is the use of an array of at least two multifilament yarns A and B, each containing at least two filaments made up of filaments, wherein at least one filament of the multifilament yarn A of at least one filament of the multifilament yarn B in the chemical identity of at least one filament polymer distinguishes as a thread sealant. Another object of the present invention is the use of a thread sealant according to the invention or a thread sealant produced by a process according to the invention for sealing screwed pipe joints.

In principle, in the present invention, all features listed within the scope of the present text, in particular those described as preferred and / or specially designated embodiments, ranges, constituents and other features of the thread sealant according to the invention, the dispenser according to the invention, the inventive method and the use of the invention in all possible and non-mutually exclusive combinations, with combinations of preferred and / or specially designated features also being considered to be preferred and / or specific.

In the following, the invention will be explained in more detail by means of embodiments, wherein the selection of the examples does not represent a limitation of the scope of the subject invention.

Examples

Tested sealants

• A:

  Thread sealant according to the invention consisting of 2 polyamide multifilament yarns (50% by weight) and one PVDF multifilament yarn (50% by weight) (according to the invention)

  B:

  PTFE tape, 100% by weight PTFE, 0.8 g / cm ³ (not according to the invention)

  C:

  Multi-fiber PTFE thread-sealed hemp, 100% by weight of PTFE (not according to the invention)

test device

• – Reduziermuffe (+GF+), Rp11/2'' x1/2'', verformbares Eisen, Zink-beschichtet, Parallelgewinde (Einheit 1)
• – Kegeliger Gewindenippel, R11/2'', Länge 200 mm, Stahl (St 33-2), konische Gewinde (Einheit 2)
• – Muffe (+GF+), Rp11/2'', verformbares Eisen, Zink-beschichtet, Parallelgewinde (Einheit 3)
• – Stopper (+GF+), R11/2'', verformbares Eisen, Zink-beschichtet, konisches Gewinde (Einheit 4)
• – Druckanschluss (auf die Reduziermuffe montiert)

Geschraubte Verbindungen bestehen zwischen den Einheiten 1 und 2 (Testgewinde 1), 2 und 3 (Testgewinde 2), 3 und 4 (Testgewinde 3).Pipe element type 1, consisting of:

• - Reduction sleeve (+ GF +), Rp11 / 2 '' x1 / 2 '', malleable iron, zinc coated, parallel thread (unit 1)
• - tapered threaded nipple, R11 / 2 '', length 200 mm, steel (St 33-2), conical thread (unit 2)
• - Sleeve (+ GF +), Rp11 / 2 '', malleable iron, zinc coated, parallel thread (unit 3)
• - Stopper (+ GF +), R11 / 2 '', malleable iron, zinc coated, conical thread (unit 4)
• - pressure connection (mounted on the reducer sleeve)

Bolted connections exist between units 1 and 2 (test thread 1), 2 and 3 (test thread 2), 3 and 4 (test thread 3).

• – 2 Reduzierstücken (+GF+), 11/2'' × 1/2'', verformbares Eisen, Zink-beschichtet, Parallelgewinde (Einheiten 1 und 5)
• – 1 kegeligen Gewindenippel, 11/2'' × 200 mm, Stahl, Zink-beschichtet (Einheit 3)
• – 2 Muffen, (+GF+), 11/2, verformbares Eisen, Zink-beschichtet, Parallelgewinde (Einheiten 2 und 4)
• – Druckanschluss (auf 1 Reduzierstück montiert)
• – Stopper (+GF+), R11/2'', verformbares Eisen, Zink-beschichtet, konisches Gewinde

Geschraubte Verbindungen zwischen den Einheiten 1 und 2 (Testgewinde 4), 2 und 3 (Testgewinde 5), 3 und 4 (Testgewinde 6), 4 und 5 (Testgewinde 7)

• Verwendete Werkzeuge: Drehmomentschlüssel DRS11 (80–400 Nm), angelegte Spannkraft: 150 Nm; Stahlbürste, Metallsäge
• Messvorrichtungen: Druckmessgeräte „Elabo” (PID002/0–10 bar)/Testmedium: komprimierte Luft; Drucksensor „HBM” (PID004/0–50 bar)/Testmedium: Stickstoff

Pipe element type 2, consisting of:

• - 2 reducers (+ GF +), 11/2 '' × 1/2 '', malleable iron, zinc coated, parallel threads (units 1 and 5)
• - 1 tapered threaded nipple, 11/2 '' × 200 mm, steel, zinc-coated (unit 3)
• - 2 sleeves, (+ GF +), 11/2, malleable iron, zinc coated, parallel thread (units 2 and 4)
• - pressure connection (mounted on 1 reducer)
• - Stopper (+ GF +), R11 / 2 '', malleable iron, zinc coated, conical thread

Bolted connections between units 1 and 2 (test thread 4), 2 and 3 (test thread 5), 3 and 4 (test thread 6), 4 and 5 (test thread 7)

• Tools used: Torque wrench DRS11 (80-400 Nm), applied clamping force: 150 Nm; Steel brush, hacksaw
• Measuring devices: Pressure gauges "Elabo" (PID002 / 0-10 bar) / Test medium: compressed air; Pressure sensor "HBM" (PID004 / 0-50 bar) / Test medium: nitrogen

test method

• 1. Rough grinding of the external threads (saw), cleaning the internal and external threads with the steel brush
• 2. Application of the sealant to the external thread
• 3. Screw the test thread using a torque wrench
• 4. Remove excess sealant with a steel brush
• 5. Perform the tests in a test chamber filled with tap water using pressure gauge and pressure sensor.

  close

  = no blistering

  leaky

  = Bubble development

Test results Test 1: 5 min after mounting and then turning back the screwed connections in test threads 1 and 2 by 45 °, compressed air, 7.5 bar Pipe element type - test no. sealant product Quantity Test thread 1 Test thread 2 1-1 A 20 turns close leaky 1-2 A 20 turns close close 1-3 A 20 turns leaky close 1-4 A 20 turns close close 1-1 B 20 turns close leaky 1-2 B 20 turns close leaky 1-3 B 20 turns close close 1-4 B 20 turns leaky leaky After 24 hours storage of the bolted test specimens at room temperature 1-1 A 20 turns close close 1-2 A 20 turns close close 1-3 A 20 turns close close 1-4 A 20 turns close close Test 2: 5 minutes after storage of the bolted test specimens for 6 hours in the heat chamber at 100 ° C and 2 hours at 20 ° C, 6 times repetition of this temperature cycle ', subsequent storage at -20 ° C for 4 h and at 23 ° C. for 2 h; Compressed air, 7.5 bar Pipe element type - test no. sealant product Quantity Test thread 1 Test thread 2 1-1 A 20 turns leaky* close 1-2 A 20 turns close leaky 1-3 A 20 turns close close 1-4 A 20 turns close close 1-1 B 20 turns close leaky 1-2 B 20 turns leaky close 1-3 B 20 turns close close 1-4 B 20 turns close leaky After another 24 h storage of the bolted test specimens at room temperature 1-1 A 20 turns leaky* close 1-2 A 20 turns close close 1-3 A 20 turns close close 1-4 A 20 turns close close Then: nitrogen, 20 bar, 5 min 1-1 A 20 turns close close 1-2 A 20 turns close close 1-3 A 20 turns close close 1-4 A 20 turns close close * for 3 min, then tight Test 3: 5 minutes after assembly; Compressed air, 7.5 bar Pipe element type - test no. sealant Test thread 4 (20 windg.) Test thread 5 (20 windg.) Test thread 6 (30 windg.) Test thread 7 (30 windg.) 2-1 C close leaky close leaky 2-2 C close close leaky leaky 2-3 C close leaky leaky leaky 2-4 C leaky close leaky close Test 4: after turning back the screwed connections in test threads 5 and 6 by 45 °, compressed air, 7.5 bar Pipe element type - test no. sealant Test thread 4 (20 windg.) Test thread 5 (20 windg.) Test thread 6 (30 windg.) Test thread 7 (30 windg.) 2-1 C close leaky close leaky 2-2 C close close leaky leaky 2-3 C close close leaky leaky 2-4 C leaky close leaky close

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0975545 B1 [0005]

Cited non-patent literature

• ISO 527 [0022]

Claims (10)

A thread sealant comprising at least two multifilament yarns A and B, each containing at least two filaments composed of filamentary polymers, wherein at least one filament of the multifilament yarn A differs from at least one filament of the multifilament yarn B in the chemical identity of at least one filamentary polymer. Thread sealant according to claim 1, characterized in that at least one of the filament polymers of the multifilament yarns A and / or B is a fluorine-containing polymer. Thread sealant according to claim 1 or 2, characterized in that the thread sealant comprises at least one further multifilament yarn C containing at least two filaments composed of filament polymers, at least one of the filament polymers of the multifilament yarn C belonging to the same polymer class as at least one of the filament polymers of the multifilament yarns A and /. or B. Thread sealant according to at least one of the preceding claims, characterized in that the proportion by weight of each of polymer classes belonging to identical filament polymers is 30 to 70 wt .-%, based on the total weight of the thread sealant. Thread sealant according to at least one of the preceding claims, characterized in that the filament polymers of the multifilament yarns used each comprise at least one polymer selected from polyamides, polyolefins, polyethylene terephthalate (PET), phenolic resins and fluorine-containing polymers. Thread sealant according to at least one of the preceding claims, characterized in that one of the multifilament yarns A and B has an elongation at break which is increased by at least 10% compared with the elongation at break of the other multifilament yarn determined under identical conditions using an identical method. Thread sealant according to at least one of the preceding claims, characterized in that the thread sealant is substantially free of sealing paste. Dispenser containing a thread sealant according to at least one of the preceding claims, comprising a hollow body, a lid part with a dispensing opening and a closure device for closing the dispensing opening, wherein the ready-threaded thread sealant is contained in the hollow body. A method for producing a thread sealant according to any one of claims 1 to 8, characterized in that at least two multifilament yarns, each containing at least two of filament polymers constructed filaments, wherein at least one filament of the multifilament yarn A of at least one filament of the multifilament yarn B in the chemical identity at least one filament polymer different, are mechanically interconnected. Use of an array of at least two multifilament yarns A and B, each containing at least two filaments composed of filamentary polymers, wherein at least one filament of the multifilament yarn A differs from at least one filament of the multifilament yarn B in the chemical identity of at least one filament polymer, as a thread sealant.