DE102011119194A1 - Laminated glass tube used in high speed bio-liquid chromatography system, has inner tube and outer tube which are joined with respect to each other - Google Patents

Abstract

The laminated glass tube has an inner tube (1) and an outer tube (3) which are joined with respect to each other. The inner tube is provided with winding portion (2) formed of tension-resistant wire, heat-resistant wire or fiber material having basalt, glass or tungsten material. The intermediate gap is provided between the inner tube and outer tube. An independent claim is included for method for manufacturing laminated glass tube.

Description

The invention relates to a laminated glass tube, comprising an inner tube and at least one further, surrounding the inner tube outer tube, wherein the tubes are joined by a thermally guided, vacuum-assisted calibration, according to claim 1.

From the DE 102 61 755 A1 is a laminated glass tube and a method for its preparation previously known. In the local composite glass tube is based on an inner glass tube and an outer glass tube, which are connected to each other via a transparent or translucent adhesive layer low stress and bubble-free. If the inner glass tube or the outer glass tube or both tubes break, the adhesive layer used should at least temporarily ensure residual capacities. With this approach, a laminated glass tube is to be created, which has an increased resistance to breakage and residual strength. In a related method of manufacturing, the aforementioned intermediate layer is first applied to the outside of the inner glass tube and / or to the inside of the outer glass tube. Then the glass tubes are joined together and the space between the inner and outer glass tube is evacuated. About a step of heating up to soften the connecting intermediate layer, the glass tubes are firmly connected. Afterwards the thus created pipe system is cooled down.

After DE 1 813 736 A1 includes acid-resistant, reinforced with fibers pipe to the prior art. According to the teaching there, tubes are made by winding a glass fiber reinforcement on a mandrel. By resin impregnation or resin preimpregnation, it is possible to cure the resin at the appropriate temperature after the wind process. This results in a fiber-wound pipe with a positive ratio of strength to weight.

In the liquid chromatography column according to EP 0 624 795 B1 is assumed by an outer metal tube having an inner surface and a first and a second end and a biocompatible inner tube. The outer metal tube is preferably made of a stainless steel or aluminum. The inner tube may contain glass fibers. At least parts of the outer surface of the inner tube communicate with at least a portion of the inner surface of the outer tube, thereby establishing a desired compressive strength.

In addition, glass columns are known with inner core tube and outer cladding tube, core tube and cladding tube are permanently connected with a special bonding method. The composite is constructed so that the inner tube takes over bearing forces and protects the outer tube. This results in a splinter-binding unit that maintains its load-bearing capacity even in the case of severe damage (see www.hitecglas.de).

From the foregoing, it is an object of the invention to provide a further developed laminated glass tube and a method for its production, wherein the arrangement to be created is to be extremely pressure and temperature resistant, so that opens up new applications.

The solution of the object of the invention is carried out with the feature combination according to claim 1 and a methodology according to claim 9, wherein the dependent claims comprise at least expedient refinements and developments.

It is therefore assumed that a composite glass tube consisting of an inner tube and at least one other, surrounding the inner tube outer tube, wherein the tubes are joined by a thermally guided, vacuum-assisted calibration.

According to the invention, the inner tube has a wrap of a tensile fiber material, as a result of the calibration process at least portions of the wrapping in the outer tube without damaging the amorphous glass structure memorize. This creates a new composite material with a variety of applications.

The wrapping according to the invention consists of a fiber bundle with a plurality of individual fibers or wires. For example, the individual fibers have a diameter of one or a few hundredths of a millimeter, wherein the entire fiber bundle has a diameter of 0.3 mm to 0.8 mm, preferably 0.5 mm.

The fibers or wires of the invention may, for. B. basalt, tungsten and / or glass fibers. Similarly, the use of wires for electrical heating would be denikbnar.

The glass transition temperature T _{G of} the tube materials used are the same, however, the melting temperature of the fiber material is different, in particular higher than that of the tube material.

The fiber material is primarily at least partially embedded in the glass of the outer tube, but optionally also in the inner tube. In other words, the fiber material presses into the outer tube. It forms here, so to speak, a bead which leads to a substantial increase in the structural strength of the overall arrangement.

In one embodiment of the invention, more than two concentric tubes may be present, wherein between at least two of the tubes, the wrap of tensile fiber material is formed.

The wrap consists of spaced helical single windings or of a crossed or a bifilar winding formation.

In this case, the wrapping is not formed so that the entire surface of each, the winding receiving glass tube is completely covered. Rather, there is a sufficiently large distance between the individual turns of the winding.

In the method according to the invention for producing a laminated glass tube, first of all the winding or wrapping of a first glass tube with the mentioned tensile fiber material and a temporary fixing of the fiber material are carried out.

Thereafter, the wrapped first glass tube is introduced into the cylindrical cavity of a second, correspondingly larger diameter glass tube. Between the two glass tubes remains only a very small gap, which is sufficient, however, to absorb the wrap without damage.

There is now the introduction of a calibration mandrel in the interior of the first glass tube. This calibration mandrel is preferably made of a metallic material or has a relation to the glass tube material other, higher expansion coefficients.

The thus created pipe system is closed and there is the application of a vacuum.

By heating the prefabricated composite on the glass transition temperature of the glass tubes, applying the inner tube to the Kalibrierdorn, followed by the heating from outside to inside the second or further tubes of the change in diameter of the first tube, so that ultimately the desired composite with final Fixing the wrapping is created. Subsequently, a controlled, slow cooling of the pipe system with removal of the calibration mandrel is realized.

As already indicated, the second glass tube may be surrounded by at least one further glass tube.

In an embodiment of this idea of the invention, a plurality of tubes with wraps may be present in the resulting concentric tube system.

The invention will be explained below with reference to an embodiment. The figures show:

1 a side view of an outer glass tube of the later laminated glass tube assembly;

2 a representation of the inner, first glass tube with wrapper;

3 a representation of the introduction of the first wrapped glass tube into the cylindrical cavity of the second, larger diameter glass tube, wherein the insertion process with the arrow in the 3 , symbolized on the right;

4 a representation of the laminated glass tube after completion of the calibration process;

5 a perspective view of the laminated glass tube according to 4 ;

6 a sectional view along the line AA after 3 with still existing space between the inner tube having the wrapping and the outer, second tube;

7 a sectional view along the line BB to 4 with the laminated glass tube, as it is as a result of the calibration process;

8th a detail longitudinal section view of the arrangement according to 3 before performing the calibration process;

9 a detailed longitudinal sectional view of the laminated glass arrangement in the state as in 4 shown after completion of the calibration process;

10 a representation of an embodiment of the laminated glass tube with a narrower winding pitch and

11 a representation similar to that according to 4 , but in perspective view.

In the embodiment is on an inner glass tube 1 By means of so-called Winding process a wrap of special tensile fibers 2 applied. The winding can be different patterns such. B. spiral, crossed or bifilar.

On the thus wrapped inner tube 1 Now one or more pipes 3 With corresponding intermediate columns 4 with the dimension A deferred such that the wrapping 2 on the inner tube 1 undamaged.

All pipes 1 ; 3 should have the same glass transition temperature T _{G here} .

The glass transition or softening temperature is the temperature at which a glass exhibits the greatest change in deformability. It should be noted that glass is a solidified liquid. As glasses inorganic glasses, but also organic glasses such. As amorphous plastics find use. The glass transition separates the underlying brittle energy-elastic range from the above soft, entropy-elastic range.

Into the inner glass tube 1 a calibration mandrel (not shown) is introduced whose outer dimensions are the later inner diameter of the inner glass tube 1 imaged, so that ultimately based on this inner diameter a precision tube is formed.

After closing the pipe system at the ends, a vacuum is applied in the pipe system.

After this step has been completed, the actual calibration of the pipe system takes place. For this purpose, the prefabricated system is heated in an oven, until the transition from the glass state to the liquid state is reached. This heating takes place in sections, but in a continuous course, over the longitudinal extent of the pipe system. Here, the inner tube lays precisely to the mandrel. Since the heating of the individual tubes of the pipe system takes place from outside to inside, all other, outer tubes follow the change in diameter of the inner tube.

After a targeted, slow cooling of the pipe system, the mandrel is due to different coefficients of expansion between the material of the mandrel and the glass tube composite system removed. The corresponding wrappings are now firmly integrated in the pipe system.

As material for the wrapping 2 According to the invention, basalt fibers, glass fibers and / or tungsten fibers or similar fibers or wires are used.

From bursting tests it has been shown that pipe systems with a diameter of 20 mm, a 5 mm pitch of the wrapping and a wrapping material made of basalt fibers can withstand pressures of more than 230 bar.

In a comparable wrapping, but consisting of a fiberglass material, bursting pressures above 240 bar were detected.

It should be noted that the tensile fiber material due to the higher glass transition temperature relative to that of the tube glass material does not form a firm connection with the surface of the glass tubes.

Only sections of the wrapping are characterized according to 7 in the outer and / or inner tube 1 ; 3 without destroying the local amorphous glass structure. So the winding does not build up any unnecessary tension in the pipe system. Rather, the wrapping leads by a quasi circumferential bead to a higher strength of the overall system. The beading can be felt haptically with appropriate diameter selection of the respective tube lying above the winding on its outer surface. However, changes in the optical properties are largely excluded.

The fibers can be combined in one embodiment into a fiber bundle, wherein the corresponding bundle then represents the wrapping. Here, good results have been achieved with a diameter of the fiber bundle of substantially 0.5 mm.

The tubes realized with the exemplary embodiment can be used as particularly pressure-resistant glass tubes for use in high-performance liquid chromatography and, above all, in biochromatography.

The 1 shows a side view of the outer glass tube 3 , The glass tube 3 has an outer radius AR.

On the first, inner tube 1 can the in 2 shown winding with a predetermined distance, ie a defined pitch are applied, which, as in the 10 and 11 shown, is narrower to increase the stability of the composite glass tube assembly, without restricting the desired view to a medium located inside the tube.

As a result of the insertion of the pipe 1 with the winding 2 in the pipe 3 creates a concentric structure, as in the 3 as well as the 6 and 8th is shown. The gap A results here from the difference between the outer radius AAR of the inner tube 1 to the inner radius or inner diameter of the outer tube 3 (please refer 8th ).

After the calibration process and the stress-free cooling of the composite assembly, as in the 7 and 9 recognizable the gap A disappears and it is the winding 2 partly in the surfaces of the pipes 1 and 3 embedded. The inner diameter IR of the inner tube 1 corresponds exactly to the desired level as a result of the calibration.

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

• DE 10261755 A1 [0002]
• DE 1813736 A1 [0003]
• EP 0624795 B1 [0004]

Claims (11)

Laminated glass tube, consisting of an inner tube and at least one further, surrounding the inner tube outer tube, wherein the tubes are joined by a thermally guided, vacuum-assisted calibration, characterized in that the inner tube is a wrap of a tensile, temperature-resistant wire or fiber material wherein, as a result of the calibration process, at least portions of the wrapping are impressed into the outer tube without destroying the amorphous glass structure. Laminated glass tube according to claim 1, characterized in that the wrapping consists of a fiber bundle with a plurality of individual fibers. Laminated glass tube according to claim 1 or 2, characterized in that the fibers consist of a Balsalt-, glass and / or tungsten material. Laminated glass tube according to one of the preceding claims, characterized in that the glass transition temperature TG of the tube materials substantially the same, but the melting temperature of the wire or fiber material is different for this purpose. Laminated glass tube according to claim 4, characterized in that the glass transition temperature of the fiber material is higher than that of the tube material. Laminated glass tube according to one of the preceding claims, characterized in that the fiber material is at least partially embedded in the glass of the outer and / or inner tube. Laminated glass tube according to one of the preceding claims, characterized in that more than two concentric tubes are present, wherein between at least two of the tubes, the winding of tensile fiber material is formed. Laminated glass tube according to one of the preceding claims, characterized in that the wrapping is formed spirally, crossed or bifilar. Method for producing a laminated glass tube, comprising the following steps: - winding or wrapping a first glass tube with a tensile fiber material and temporarily fixing the fiber material; - Introducing the wrapped first glass tube into the cavity of a second, larger diameter glass tube; Inserting a calibration mandrel into the interior of the first glass tube; - closing the pipe system and applying a vacuum; Heating the prefabricated composite to at least the glass transition temperature T _{G of} the glass tubes, then applying the inner tube to the calibrating mandrel, the second tube or the following tubes following the change in diameter of the first tube by heating from the outside to the inside and fixing the wrapping is, and - controlled, slow cooling of the pipe system and removing the calibration mandrel. A method according to claim 9, characterized in that the second glass tube is surrounded by at least one further glass tube. A method according to claim 10, characterized in that in the resulting concentric pipe system a plurality of tubes are present with windings therebetween.

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