DE102007042487A1 - Method for producing a gasket, gasket and its use - Google Patents

Abstract

The invention relates to a method for producing a seal (12, 26), in which a moldable, vulcanizable material (2) is brought into a predetermined shape and vulcanized only in an edge region (16) of the molded material, as well as after this seal produced seal (12, 26). The invention further relates to a seal (12, 26) made of a moldable, vulcanizable material (2), which is vulcanized only in an edge region (16). Finally, the invention relates to the use of the seal (12, 26) for sealing of boilers and for sealing cylinder heads.

Description

The Invention relates to a method for producing a seal, a seal and its use. Find the seals of the invention Use z. B. in the construction of Gußheizkesseln, especially at huge Boiler plants, or in other areas where the seals are exposed to high temperatures.

At the Construction of industrial facilities, public buildings as well as big ones residential buildings become common Used boilers that are so big that they are not in one Factory made and transported to destination as a whole can be. such Boiler systems are therefore usually made in parts ("links"), which are mounted on the spot. The kettles have to be sealed between the members smoke gas tight. Often it acts it is the kettles to custom-made, so that the Use of preformed geometrically determined seals as not expediently proves.

Also are used in the sealing of smaller boilers sealing cords, if a seal with plastic sealant (Kesselkitt) not economical is or does not seem appropriate.

Therefore In the prior art gaskets are used in the on Connecting points of two boiler members formed grooves formed and become a corresponding spring of a subsequent boiler member to shape. Furthermore, groove-groove systems are common in which sealing cords are used come.

in the The prior art is known, finished vulcanized seals to use, which due to the complete crosslinking only are still elastically deformable. It has been shown, however, that the Use completely vulcanized seals is problematic because the seals are high elastic To exercise restoring forces even to a bursting of each other and thus compressed already sealed boiler members can lead. In addition, such a Squeeze seal out of the feather bed, increasing the tightness the boiler system is no longer guaranteed. It also happens that such seals due to the high pressure in the tongue and groove area over the elastic area are claimed and thus the networked Sealing structure is irreversibly destroyed by elongation at break. Such a claimed Gasket can no longer guarantee the gas-tightness of a boiler.

such vulcanized seals are made according to one in the prior art known processes prepared by an unvulcanized molded Sealing strand is exposed to a microwave field, which the material over the uniformly heated throughout the cross-section and thus fully vulcanized.

One Other known from the prior art approach provides a to use unvulcanized lute, which by means of spraying introduced into a groove or a spring region of a boiler member is networked or dried there during operation of the boiler. Problematic however, here is that to provide the cement a pump system is required, which is the putty from a reservoir to Transported and that the putty is still sticky, so on the construction sites existing dirt and dust on the Settle putty and affect the sealing effect.

task The invention is thus a method for producing a To provide a seal, a seal and a use of a seal, which the disadvantages of the known from the prior art method for the production of seals or sealing cords overcome and good sealing results with low failure rates with excellent processability combines.

to solution This object is a method for producing a seal according to the claim 1, a seal according to claims 9 and 10 and a use of the seal according to claim 14 specified.

The inventive method for producing a seal provides that a moldable material is brought into a predetermined shape and vulcanized and / or crosslinked only in an edge region of the molded material. As a result, the seal produced in this way has in cross-section a plurality of regions, an outer, vulcanized and / or crosslinked edge region and an inner, non-vulcanized and / or uncrosslinked core region. The seal thus has a plastically deformable soul. The edge area is no longer sticky due to vulcanization and can, for example, be wound up after the production on rolls and processed like a vulcanized seal on the construction site. The fact that the inner area is not vulcanized, this is still plastically deformable, so that the elastic rear part forces emanating from the seal, are greatly reduced overall. This prevents the blocked boiler components from bursting open and furthermore minimizes warping and damage to the seal with the resulting boiler system leaks. The resulting inventive seal made of moldable, vulcanizable material is only in one Edge area vulcanized or crosslinked.

One Another advantage of a partially vulcanized seal is that these due to the plastic deformability of the inner area (Soul) of the seal itself repaired when the outer vulcanized shell at should rupture the boiler assembly. The plastically deformable Material flows from the soul in the damaged Edge area and seals it off again.

The crosslinked according to the invention provided partially vulcanized seal due to the boiler temperatures at initial startup of the Boiler itself and thereby takes its final vulcanized form and property.

One Another advantage of the partially vulcanized seal is that these better compensate for manufacturing dimensional tolerances of the boiler elements as complete vulcanized seals and also as putty seals, since the former have no plastic deformability more and the latter tends pushed out of the groove spring system rather than within the groove spring system be moved.

Especially It is advantageous if the seal as a round or profile cord / strand is formed. Because boiler often have individual shapes and the seals can be used as universally as possible should, it has been shown that these claims best with a seal can be fulfilled in round or profile cord form.

alternative The seal can also be shaped as a round / profile molded seal. Molded seals are already finished molded seals for specific Applications. examples for this are For example, seals in the automotive sector for sealing, for example the engine block or attached components such as gearbox. Also in many other areas, for example in the heating industry in the Laying pipe systems, such seals are used. For such cases is the seal preferably preformed, for example as round or profile molding gasket.

In further embodiment of the invention is provided with advantage that the sealing material for producing the seal means Infrared radiation and / or by means of heating elements and / or air heaters in the edge region to a temperature above a crosslinking temperature of the material is heated. Such heating processes heat due to the regularly very much poor heat conduction behavior the sealing material mainly the edge region of the material up and lead there to a local networking. In this way can be guaranteed be networked that only one edge region of desired thickness and not also an interior area adjacent to the edge area the seal.

advantageously, the material is in a heat channel with controllable and / or controllable cycle time and / or temperature heated. This allows an accurate setting of the desired Parameters are achieved, even when producing seals of various Dimensions.

When Particularly suitable material has HTV silicone (HTV = high temperature, vulcanized) and fluorinated rubber. Both materials are sufficiently temperature resistant to temperatures around the 300 to 400 ° C to withstand and point it over In addition, a sufficient chemical resistance to combustion gases, that can arise in kettles, as well as against condensates, heating oils and boiler cleaner on. HTV silicone is comparatively inexpensive whereas fluororubber provides even higher temperature resistance having.

Prefers The molded material has a thickness between 2 mm and 25 mm. In particular, thicknesses between 4 mm and 6 mm and between 12 mm and 18 mm proved to be particularly suitable. The thinner variants find use in filigree applications, whereas the thicker Variant especially for large ones Boilers is used. Such boilers exist, for example made of cast iron or cast aluminum, which due to the manufacturing process to tensions and larger dimensional tolerances tend to the finished part.

In Another advantageous embodiment, the seal by extrusion process produced. This allows in particular continuous profiles easy and with high precision produce. The seal may also undergo a subsequent calibration process run through.

One another independent Thought of the invention provides a seal, which after the previously described Process is made.

Further Objectives, advantages, features and applications of the present Invention will become apparent from the following description of a embodiment based on the drawings. In this case, all described and / or depicted features alone or in any meaningful combination the subject matter of the present invention, also independent of their summary in the claims or their dependency.

It demonstrate:

1 a schematic flow chart for producing inventive seals;

2 a cross section through a seal according to the invention;

3a , b each have a cross section through a tongue and groove joint of a boiler and

4 a molded seal according to the invention for a cylinder head of a motor vehicle.

1 symbolically shows the method for producing inventive seals.

In a first step A becomes a raw material 2 made in a well-known manner. As raw material 2 especially HTV silicone or fluorinated rubber come into question.

In a second step B, the moldable material 2 by means of an extruder 4 in a round cord form 6 transferred by means of a conveyor system 8th is transported away.

to Production of strings different thickness can different extrusion masks with different diameters be used. Also, the production of sealing cords is different Profiles (eg round or profiled) by selecting suitable masks possible.

To the extrusion can be provided an unillustrated calibration which reduces the manufacturing tolerances.

In a next step C, the cord becomes 6 in a heat channel 10 transported in, in which the string 6 is heated externally. The heat channel 10 works with infrared radiation, which only in the edge area of the cord 6 is absorbed. Alternatively, other heating devices may be used, for example heating elements and / or warm air generators that are externally applied to the cord 6 act. The heat channel 10 is in terms of transport speed and in terms of infrared performance, so in terms of the cord 6 acting temperature, controllable to set a desired edge region thickness.

The string 6 leaves the heat channel 10 as a finished seal 12 , which can be cooled in a possible further intermediate step, not shown.

In a final step D, the seal 12 on spools (rollers) 14 rolled up and ready for storage and delivery to the user. It is also conceivable to assemble the sealing cord into ready-to-use lengths according to customer requirements.

2 shows a cross section through a seal according to the invention 12 ,

The seal 12 has a thickness D _G of 5 mm, with thicknesses between 2 mm and 25 mm are possible, in some cases, even more sizes can be provided. The seal 12 has a border area 16 on, in which the material is fully vulcanized. The border area 16 has a thickness D _R of 0.5 mm, wherein in principle thicknesses between 0.1 mm and 5 mm, depending on the thickness D _{G of} the seal 12 are adjustable.

To the edge area 16 closes a transition area 18 on, in which the degree of crosslinking decreases from the outside to the inside. The transition area 18 created by heat conduction of the heat introduced from the outside into the interior of the seal 12 , The transition area 18 has a thickness D _Ü of about one third of the thickness D _{R of} the edge region.

At the edge area inside a core area closes 20 which is almost completely unvulcanized. The core area (soul) 20 is therefore plastically deformable. The elastic solid edge area 16 spans the core area 20 thus like a shell.

The 3a and 3b each show a cross section through a connecting region between two boiler members 22 . 24 a large boiler plant with an inserted seal 12 ,

3a shows a unmounted state and 3b a mounted (locked) state. By inserting the groove of the boiler member 22 in the spring of the boiler member 24 becomes the inserted seal 12 plastically deformed and lies around the spring of the boiler member 22 , The plastic deformation of the seal 12 causes a particularly tight closure between the boiler members 22 . 24 , wherein due to the seal according to the invention 12 the risk of damage from tensions in the seal 12 is reduced. The seal 12 then vulcanized during boiler operation, retaining its new shape for good.

4 shows a schematic mold seal 26 , The molded seal 26 is intended for use in a valve housing of a car, where it serves to seal the valve housing on the engine block. Such seals are very susceptible to assembly errors in the prior art, which is due to a molded seal according to the invention 26 can be prevented. This can deform plastically, whereby the tightness of the cylinder head gasket and the stop In operation, even with minor assembly errors are guaranteed.

2

material

4

extruder

6

line

8th

conveyor system

10

heating tunnel

12

poetry

14

Rolls / coils

16

border area

18

Transition area

20

core area

22 24

boiler sections

26

shaped seal

A

first step

B

second step

C

third step

D

fourth step

D _G

total thickness

D _R

thickness border area

D _Ü

Thick transition area

Claims (17)

Method for producing a seal ( 12 . 26 ), characterized in that a moldable material ( 2 ) is brought into a predetermined shape and only in an edge region ( 16 ) of the molded material is vulcanized and / or crosslinked. Method according to claim 1, characterized in that the material ( 2 ) as a round or profile cord or strand or as a molded seal ( 6 ) is formed. Method according to claim 1 or 2, characterized in that the material ( 2 ) by means of infrared radiation and / or heating elements and / or warm air generators in the edge region ( 16 ) to a temperature above a crosslinking temperature of the material ( 2 ) is heated. Method according to one of the preceding claims, characterized in that the material ( 2 ) in a heat channel ( 10 ) is heated with controllable and / or controllable cycle time and / or temperature. Method according to one of the preceding claims, characterized in that as material ( 2 ) HTV silicone or fluororubber is used. Method according to one of the preceding claims, characterized in that the shaped material ( 2 ) is formed to a thickness D _G between 2 mm and 25 mm, in particular between 4 mm and 6 mm or between 12 mm and 18 mm. Method according to one of the preceding claims, characterized in that the edge region ( 16 ) has a thickness D _R between 0.1 mm and 5 mm, in particular 0.5 mm to 3 mm. Method according to one of the preceding claims, characterized in that the seal ( 12 . 26 ) is produced by extrusion processes. Seal made by the process according to claims 1 to 8th. Seal made of a moldable, vulcanizable or crosslinkable material ( 2 ), characterized in that the seal ( 12 . 26 ) only in a peripheral area ( 16 ) is vulcanized or crosslinked. Seal according to claim 10, characterized in that as material ( 2 ) HTV silicone or fluororubber is used. Seal according to claim 10 or 11, characterized in that the seal ( 12 . 26 ) is strand or string-shaped or a molded seal. Seal according to one of claims 10 to 12, characterized in that the material ( 2 ) is formed to a thickness D _G between 2 mm and 25 mm, in particular between 4 mm and 6 mm or between 12 mm and 18 mm. Seal according to one of claims 8 to 11, characterized in that the edge region ( 16 ) has a thickness D _R between 0.1 mm and 5 mm, in particular 0.5 mm to 3 mm. Using a gasket ( 12 . 26 ) according to one of claims 9 to 14 for the sealing of boilers ( 22 . 24 ). Using a gasket ( 12 . 26 ) according to claim 15, characterized in that the seal ( 12 . 26 ) in a groove of a boiler member ( 24 ) is inserted and a spring or another groove of another boiler member ( 22 ) in the groove of the boiler member ( 24 ) is introduced. Using a gasket ( 12 . 26 ) according to one of claims 9 to 14 for sealing valve covers of vehicles.