• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a flexible elongated sealing strip (9) obtained by cutting off a film (1) from PTFE rolled to form film (1) for the purpose of sealing threaded connections. The longitudinal direction of the sealing strip (9) is at least approximately normal to the rolling direction of the film (1).
    公开号:AT517232A4
    申请号:T506/2015
    申请日:2015-07-29
    公开日:2016-12-15
    发明作者:Josef Bachmair；Josef Seiringer
    申请人:Josef Bachmair；Josef Seiringer；
    IPC主号:
    专利说明:

    description
    The invention relates to a flexible elongated sealing strip made of PTFE for the sealing of threaded connections.
    Already in 1961 was proposed by the US 3002770 A publicly, as a sealing liner between the screw and nut threads in pipe joints to use a band of PTFE (polytetrafluoroethylene). For the production of the tape powdered PTFE is mixed with a small proportion of an oily additive, extruded and rolled on a calender roll stand to a long, thin band and finally wound up. On the calender roll stand, the strip is stretched so that its specific wipe comes to lie at 1.2 to 1.8 g / mms. (PTFE bodies formed by compression and kneading of PTFE powder have the peculiarity that, when flowing, they not only change the shape but also become porous, thus decreasing their density.). For applying the tape for sealing this is anset2t on the screw thread and wound around screw thread while maintaining tensile stress, that overlap longitudinal portions of the tape in the winding formed on the screw thread and adhere winding layers at least slightly to each other. On the wrapped screw thread (typically it is on the outside of the lateral surface of a pipe end) of the part to be connected thereto is screwed with a nut thread attached to it. As intended, the sealing tape seals the gap between the screw and nut threads and it also acts as a sliding layer in the process of screwing.
    Compared with the combination of hemp fibers and a lubricant as a sealant PTFE is advantageous as a sealant, because it is chemically stable over decades, so that no substance to the transported in a sealed pipe and medium because the lubricating effect is maintained over decades, so that the sealed threaded connections can still be solved damage-free even after years.
    The most significant disadvantage of the sealing tape according to US 3002770 A has been found that the compound thus produced is not (sufficiently) tight, especially when screw thread and nut threads are not only screwed into each other, but also once screwed in the opposite direction - like It is almost always required for adjusting parts of pipelines.
    CH 544127 A describes a sealing tape which is very similar in application, manufacture and disadvantages of that of US 3002770 A. According to the invention, it is more stretched than the sealing tape according to US 3002770 A, so that it has a slightly lower density. Thus, the manual work when making a sealing threaded connection may be a bit easier, because the band is softer and therefore better conforms to the thread grooves. Turning back of screwed together parts is not possible because the tightness is no longer guaranteed.
    DE 10 2006 023 729 B3 describes a thread sealing thread made of PTFE. It is formed by folding or twisting or braiding a strip, which has been produced in accordance with the previously described methods, into several layers or partial strands to form a thread whose cross-sectional area has a plurality of completely or almost completely separate partial areas. In addition, the thread is wetted with a lubricant- The thread is better than the sealing tapes according to the previously mentioned writings as a sealant. But it is also more expensive to manufacture and the required lubricant is also often perceived as disadvantageous.
    EP 1 802 906 Bl describes a PTFE sealing thread for sealing pipe connections. The thread consists of only a single filament with a rectangular cross-sectional area; this is a maximum of 2mm by 3mm. The density of the material is very low (between 0.7 and 1.1 g / mm3) so that the thread is plastically very well deformable. For sealing, it is used together with a liquid lubricant. The handling of this sealing thread is perceived as not very comfortable. That always a lubricant must be used, is also perceived as a disadvantage.
    Common to all hitherto described threaded fasteners is that they are made of PTFE, that they are formed by plastic deformation such as extrusion and / or rolling, and that they are elongated with their longitudinal direction parallel to the main deformation direction during manufacture (extrusion, rolling, stretching). is.
    A disadvantage of the known, discussed sealants is that they leave either to be desired in the sealing effect, or that they urgently require the addition of a (liquid) lubricant.
    The problem underlying the invention, in contrast, is to provide a PTFE sealant for threaded connections, which is comfortable to handle, reliably seals even when the threaded connection is once again screwed something in the opening direction and yet requires no lubricant application. To solve the problem, it is assumed that the sealant is a flexible, elongated strip of film rolled to PTFE, which is intended to plastically stretch in the longitudinal direction by a tensile force to form a thread seal and while maintaining tension and in the circumferential direction of the thread around the Screw thread is wound so that overlap longitudinal portions of the threaded strip.
    In contrast to conventional sealing means formed as a rolled PTFE film, it is proposed that the longitudinal direction of the elongate strip is not parallel to the rolling direction in the production of the film from which the strip is made, but normal in the film plane. Surprisingly, the strip thus formed has the best properties for use as a strip-shaped, elongated thread sealant.
    Fig. 1 - illustrates strongly stylized an exemplary
    Manufacturing method for an exemplary weather strip according to the invention. The arrows show the direction of movement of the processed material.
    According to Fig. 1 for the production of a film 1 of PT FE on a Kalanderwalzgerüst - usually obtained by extrusion of a PTFE polymer - original strand 2 in the gap between the two rolls of pairs of rollers 3, 4 formed by pressure ver. In the longitudinal region between in the direction of movement of the partially processed strand 5 spaced roller pairs 3, 4 or rollers 6, 7, the strand can also be stretched slightly, so be stretched by tensile plastic, the direction of the tensile stress and the plastic deformation caused thereby parallel to the rolling direction of the strand 5 lies.
    Experiments have shown that the film 1 thus obtained is very strongly anisotropic with regard to plastic deformability.
    Against plastic deformation parallel to the main deformation direction (rolling and stretching direction) present during production, the film 1 is many times stronger than against plastic deformation in the plane of the film 1 transverse to the main deformation direction present during production. Upon deformation of the film 1 by tensile stress parallel to the prevailing in the production of the main deformation direction - ie in its longitudinal direction - the elongation at break is only about one twentieth of that value, the
    Elongation at break has, if the deformation of the film 1 by tensile stress in the film plane is normal 2U of prevailing in the main deformation direction. (The elongation at break with deformation in the longitudinal direction of the film 1 is in the range of 12 to 15Ϊ, when deformed transversely to it is about 300¾.)
    The dashed lines in FIG. 1 symbolize straight lines of intersection 8 through which the film 1 according to the invention is cut into elongated strips, which are the sealing strips 9 according to the invention to be produced. Of essential importance according to the invention is that the cutting lines 8 are normal to the direction of movement of the strand 2, 5 and the film 1 on the calender rolling mill formed by pairs of rollers 3, 4 and rollers 6, 7. For forming a sealed threaded connection - such as between a screw-threaded tube end and a female-threaded sleeve - a sealing strip 9, which is originally at least about as long as the circumference of the screw thread, is made double by manual pulling at its ends plastically deformed up to four times its previous length, then wound from the front side of the nut thread on this, being kept under constant tension. Where two layers of the so wound on the thread sealing strip 9 touch, the two layers adhere sufficiently strong to each other that the winding holds stable even without lubricant or adhesive. If the clearance between the screw and the nut thread is very large, significantly more than two layers of sealing strip 9 can easily be applied to the screw thread in order to bridge the gap. It can also be easily successively applied a plurality of previously separate sealing strips 9 successively and one above the other on the screw thread.
    After completing the winding of weather strips 9 on the screw thread, the part having a nut thread is screwed onto the wrapped screw thread. All these actions are so easy to carry out that the execution is immediately mastered in case of need even by untrained persons. The result is reliable tightness between the parts screwed together, even if the depth of the screw connection may need to be readjusted and to the screwed parts also opposite to the screwing against each other must be rotated.
    The material properties of the weather strip 9 by which these advantages are achieved are achieved by the described, specifically applied during assembly stretching. The material of the sealing strip 9 is soft and supple by this stretching and thus lays perfectly in the threads and ensures after screwing an absolutely tight threaded connection.
    This novel technique is universally applicable, ie for all common threaded connections such as NPT threads, pipe threads, threaded fittings, without the additional application of lubricant. For the applied during assembly stretching of the weather strip 9, there is no narrowly limited specification. In any case, good results can be achieved if the sealing strip 9 is stretched to at least twice to four times its original length.
    At sizes of sealing strip 9 according to the invention have been proven:
    Thickness of 50 - 500pm,
    Width of 5-30 mm length from 50 - 200mm (depending on the thread dimension) For the density of the undeformed sealing strip 9 the range of 1.20 - 1.80 g / cm3 has worked well.
    The sealing strip according to the invention does not necessarily have to be an undivided flat piece as shown. It may, for example, also be a so-called multifilament, that is to say a structure composed of many elongated, slender strips or threads. It may, for example, also be a bundle-like structure which is formed by slitting a monolithic strip. Decisive is the described sequence of deformations. (Immediately prior to assembly, strong plastic strain in the longitudinal direction, which is the winding direction around the thread, but normal to the direction in which the material was mainly deformed during manufacture.)
    A readjustment of the sealing thread fitting often required during assembly up to a quarter turn in both directions is possible even with stainless steel connections, without endangering the tightness.
    The sealing strip according to the invention also prevents rubbing of the parts screwing together with each other, which is particularly feared in the case of stainless steel threads.
    On (known) advantages of the execution of a sealing strip made of PTFE without further additives, are briefly listed: - Excellent sliding properties, very low coefficient of sliding friction - Excellent chemical resistance
    - Temperature inlet range from -200 ° C to 260 ° C - No water absorption - Non-aging - No hardening, embrittlement or similar - No chemical reactions with the media in the pipes.
    Application tests have shown that stainless steel fittings and pipe threads designed for nitrogen as pressurized fluid, which have been sealed with sealing strips according to the invention, withstand pressures of up to 200 bar and above without problems. Water pipe fittings that have been sealed with sealing strip according to the invention, can easily withstand 25 bar. In both cases tightness is still present even when screwed threaded connections several times by a quarter turn and screwed back on.
    The quick and easy way of application is a big advantage for fitters. The error rate drops drastically.
    权利要求:
    Claims (2)
    [1]
    claims
    1. By a rolled foil (1) formed, flexible elongated sealing strip (9) made of PTFE for the sealing of threaded connections, characterized in that the longitudinal direction of the sealing strip (9) is at least approximately normal to the rolling direction of the film (1).
    [2]
    2. A process for the production of a weather strip (9) wherein PTFE is rolled into a film (1), characterized in that the film (1) formed by rolling along cutting lines (B), which in the plane of the film (1) at least approximately normal to the direction of rolling, is cut into elongated strips whose longitudinal direction is at least approximately normal to the direction of rolling on the film (1).
    类似技术:
    公开号 | 公开日 | 专利标题
    DE2417640C2|1982-03-04|Pipe connection connection
    EP3124206B1|2020-08-26|Weather strips made from ptfe
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    CH622599A5|1981-04-15|Process and device for fastening a sleeve in a fluid pipeline
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    DE593470C|1934-02-28|Hose or cable coupling in which a coupling piece surrounds the free end of the hose or cable with a sleeve
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    AT390133B|1990-03-26|CONNECTING DEVICE
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    DE2937193A1|1980-03-20|Device for coupling plastics pipeline sections - has tubular take=up and inserting sections with ring seal and clamping ring
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    DE2427560A1|1975-12-18|Connector for heating radiator and pipe - has a threaded and spherical end for efficient sealing
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    同族专利:
    公开号 | 公开日
    AT517232B1|2016-12-15|
    EP3124206B1|2020-08-26|
    ES2832809T3|2021-06-11|
    EP3124206A1|2017-02-01|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    SE392582B|1970-05-21|1977-04-04|Gore & Ass|PROCEDURE FOR THE PREPARATION OF A POROST MATERIAL, BY EXPANDING AND STRETCHING A TETRAFLUORETENE POLYMER PREPARED IN AN PASTE-FORMING EXTENSION PROCEDURE|
    AU1127395A|1994-09-02|1996-03-27|W.L. Gore & Associates, Inc.|Low creep polytetrafluoroethylene gasketing element|
    AU2003236737A1|2003-06-24|2005-01-04|Manegro Administracao E Participacoes Ltda.|A process for manufacturing a ptfe filament, and a ptfe filament obtained by this process|EP3640170B1|2018-10-18|2021-06-23|Henkel AG & Co. KGaA|Combination of a dispenser for dispensing portions of sealing material with a sealing material|
    CN110629303B|2019-09-20|2021-07-20|常州华福环境科技股份有限公司|Manufacturing process of high-strength low-elongation polytetrafluoroethylene ultra-fine filaments|
    CN110528131B|2019-09-20|2021-07-23|常州华福环境科技股份有限公司|Manufacturing process of high-strength low-friction polytetrafluoroethylene sewing thread|
    法律状态:
    2021-03-15| MM01| Lapse because of not paying annual fees|Effective date: 20200729 |
    优先权:
    申请号 | 申请日 | 专利标题
    ATA506/2015A|AT517232B1|2015-07-29|2015-07-29|Sealing strip made of PTFE|ATA506/2015A| AT517232B1|2015-07-29|2015-07-29|Sealing strip made of PTFE|
    EP16001647.3A| EP3124206B1|2015-07-29|2016-07-27|Weather strips made from ptfe|
    ES16001647T| ES2832809T3|2015-07-29|2016-07-27|PTFE sealing band|
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