JPS6232108B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a carrier material in the form of a web or plate, which carrier material is coated with a soft covering sheet of a soft compound material, in which case the soft compound material is in the form of fibrous and optionally Contains a powdered base material and a binder and is vulcanizable,
and in that case the carrier material is formed into a flat plate,
And the soft covering sheet is this soft covering sheet 100
% of at least 80% asbestos-free pulverulent mineral base material, approximately 6% binder and maximum 14% asbestos-free fibers, in particular for producing flat packing and also insulating plates. , West German Patent Application P3136015, No. 7-16, relates to a web or plate reinforced with a carrier.

A carrier-reinforced web of the above-mentioned type is known from German Patent Specification No. 21 46 309. The above-mentioned publications relate in particular to methods for producing webs reinforced with such carriers.
In this case, a fiber-reinforced pasty elastomeric compound (as a soft compounding material) is applied to the metal carrier material with the use of additional water. This additional water is necessary to avoid sticking of the pasty compound to the calender rollers. At present, the pasty soft compound consists of a rubber-asbestos mixture in a ratio of approximately 1:1.

As already mentioned, carrier-reinforced webs of the aforementioned type are used as starting material for producing mechanically and thermally highly stressed flat packings, for example cylinder head packings of internal combustion engines. be able to. For such sealing members exposed to high mechanical loads, especially in flatpacking, the following properties are required: (a) Compliance (b) Pressure resistance (c) Repulsion (d) Airtightness - and liquid tightness (e) thermal stability (f) longitudinal and transverse stability (g) strength of the cut line (h) corrosion resistance. Webs reinforced with reinforced carriers, or flat packings subsequently produced therefrom, have major drawbacks. The pasty starting state of the soft compounding material required in the known process presupposes its high rubber content. As a result, packing plates made from carrier-reinforced webs have only a very low pressure resistance, insufficient heat resistance and completely insufficient longitudinal and lateral stability.

Additionally, pasty compounds of soft compound materials adhere to calender rollers during web production. As already mentioned above, attempts have been made to counteract this drawback by supplying additional water.
However, this directly results in another very significant disadvantage, particularly if a carrier plate without mechanical fastenings is used, in that the adhesion of the pasty soft compound to the carrier material is significantly reduced. It is clear that such soft compounded materials are unsuitable for the production of flat packings which are required to have the above-mentioned performance criteria.

The object of the invention according to West German patent application P 31 36 015, no. The above-mentioned disadvantages of reinforced webs or plates or products manufactured therefrom, such as packing, are avoided and furthermore a simple and inexpensive production of such carrier-reinforced webs or plates is possible. It was hot.

According to the invention, the object generally comprises:
This was achieved in that the carrier material was formed in the form of a plate and the coating of soft compound material furthermore consisted of a largely asbestos-free powdered mineral base.

In the case of a web or plate reinforced with a carrier according to the invention, the starting state of the soft compound material is no longer pasty. This advantageously allows
It is possible to reduce the rubber content and thus obtain a greater pressure resistance of the web or of the flat packing produced therefrom. Another invention of the above
One important advantage is that it is no longer necessary to apply additional water to the calender rollers. This again gives an advantage to the excellent adhesion of the soft compound material roller-pressed to the carrier material, and in particular when flat sheet or foil or fleece or woven fabric is used as the carrier material. It can be obtained even if According to the invention, it is therefore possible to completely eliminate mechanical fixings in the carrier material. A very advantageous result of this is that carrier-reinforced webs or plates and products made therefrom, such as flat packings, such as cylinder head packings, are superior to known web-like packings or flat packings. It can be made extremely thin.

Another major feature of the invention is the method for manufacturing such carrier-reinforced webs or plates, in which the soft compound material is applied continuously to both sides of the carrier material by calender rollers and after roller crimping. During drying and vulcanization in the oven, each side of the carrier material to be coated is provided with a separate set of calender rollers, and the soft compound material is applied as a free-flowing bulk material to each side of the carrier material. It is characterized in that the two rollers of each calender roller set are driven at different circumferential speeds, each being applied just before its entry into the passage slit between the calender roller sets.

The different circumferential speeds of the two rollers of each calender roller set create friction in the soft compound material applied to the carrier material, and this friction results in excellent adhesion of the soft compound material to the surface of the carrier material. Produces adhesion. Furthermore, the different circumferential speeds of the calender rollers provide the great advantage that it is no longer necessary to apply additional water to the calender rollers. Again, the omission of additional water results in the already mentioned excellent adhesion of the soft compound material roller-pressed to the carrier material.

A further great advantage of the invention is that adhesives, which are generally applied to the carrier material before coating, may be omitted in most possible applications.

However, on the other hand, the invention in no way precludes the use of adhesives. Thus, for example, if the web according to the invention is used as starting material for producing cylinder head packings exposed in water, it is recommended to provide the carrier material with an adhesive.

However, in all cases, ie irrespective of whether the adhesive is applied to the carrier material or not, in the invention there is no device for drying the adhesive (as required in the method according to DE 21 46 309).
This represents a significant energy saving compared to DE 2146309.

If an adhesive is used, it is furthermore a practical advantage in said invention not to allow the adhesive to dry out, since the tacky adhesive still ensures good adhesion of the soft compound to the carrier material. It is from.

The method according to the invention, as already mentioned above, allows the desired adhesion of the soft compound material to the carrier material without the coating sticking to the calender rollers and resulting in failures. Another significant advantage of the invention is that only one oven is required for the drying and vulcanization of the applied soft compound material and this process can proceed in a single working step. Compared to the known process, which required three or four furnaces for this purpose, with the invention it is therefore possible to realize significant savings in terms of the purchase of equipment necessary for production, the volume required and the energy consumption. It is.

Further savings within said scope are such that, in the method according to the invention, the required thickness and density as well as the dimensional accuracy of the applied soft compound material layer are achieved in a known manner without the subsequent connection of customary correction rollers. It can be obtained by

Finally, it should be noted that the method according to the invention is less complex with respect to soft compounded materials compared to the state of the art according to German Patent Specification No. 2146309.
It has the advantage that processing using extrusion and tablet molds is unnecessary.

The method according to the invention thus requires considerable costs and safety outlays, as is necessary in the known method according to German Patent Specification No. 2146309 (see in particular column 5, section 3 of said specification). This makes it possible to omit such pre-processing. On the other hand,
The method according to the invention requires only one working step.

The object of the invention is to further improve the web or plate reinforced by the carrier according to the invention in terms of the following properties: 1. Elasticity (repulsion) and conformability; 2. Tightness of the soft compound material. 3. Reduction of stickiness According to the invention, this object is achieved in that the asbestos-free pulverulent mineral substrate is composed of a thermally and chemically untreated material, preferably sheetrock powder, and Optionally, it is formed from additional components consisting of chemically and/or thermally treated materials, the solution being that the ratio of treated material to untreated material is at most 25:55.
Instead of sheet rock powder, mica can be used as a chemically and thermally untreated component of the asbestos-free powdered mineral matrix.

Expanded graphite is preferably used as the chemically and thermally treated substrate or expanded vermiculite as the only thermally treated substrate.

Expanded graphite is produced by introducing a group of different atoms between the layers of the graphite crystal lattice (chemical treatment) and cracking it using heat (thermal treatment) from soft natural graphite ore, which is pure carbon. It is obtained by This heat treatment (thermal cleavage) results in an increase in the interlayer distance of the graphite crystal lattice.

The name "Vermiculite" for substrates that can be used in place of graphite is the geological name for a group of flaky hydrated minerals that have the appearance of mica. The raw material vermiculite consists of thin plate-shaped pieces, which contain water of crystallization with microscopic fineness and expand to many times their initial volume under the action of instantaneous heat at 800-1000°C and with the release of steam. do. In this case, heat treatment of the raw material vermiculite is mentioned.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method for producing a carrier-reinforced web or plate according to the invention will be explained in detail below with reference to the exemplary embodiments of the drawings.

In the drawing, the carrier material, designated 10, is taken off from a winding drum (not shown).
It may be a strip of sheet metal or foil or fleece or woven fabric. The raw material for the carrier material may be metal, plastic or even paper. The shape and raw material of the carrier material depends on the respective application of the web or plate to be produced. The direction of conveyance is indicated by an arrow 11. The important stations of the illustrated apparatus are two calender roller sets 12, 13 or 14, 15 and a drying and vulcanizing oven 16. 1 each for calendar roller sets 12, 13 or 14, 15.
Two containers 17 are arranged which contain a soft stock material in the form of free-flowing bulk material and apply it into the passage slit between the rollers 12, 13 or 14, 15 of the respective calender roller set. used for. The soft stock material disposed in container 17 includes substances in the form of flowable bulk materials.

In particular, the soft compound material, in the case of the invention, consists of at least 80% asbestos-free powdered mineral substrate, such as mineral powder, and only about 6% binder. The remainder, generally about 3% and a maximum of 14%, is distributed in asbestos-free fiber materials, such as polyamide-cellulose or other natural or synthetic fibers. Advantageously, the base material is sheet rock fine powder. However, the use of other asbestos-free powder minerals is also conceivable. The binder component of the flexible compound material, preferably the rubber-toluol mixture (in the starting state), is limited to about 6%.

In contrast, in the case of the present invention, the soft compounded material comprises, within the scope of the formulation according to the invention, 55-80% chemically and thermally untreated material, preferably vermiculite powder, and 25-80% % of chemically and/or thermally treated materials, preferably consisting of expanded vermiculite.

The materials are mixed in a mixer and the desired crushed soft blended material is obtained. The manufacturing method using the illustrated apparatus then proceeds in detail as follows. The as yet uncoated carrier material, for example a sheet metal strip, is passed between the two rollers 18,19. In this case (i.e., if desired), the top surface may be coated with an adhesive. An adhesive is placed in the container 20 on top of the top roller 18 . When coating the carrier material 10 with adhesive is desired, the adhesive is "drawn" from the container 20 by a suitable feeding device (not shown) and applied to the upper roller 18. The adhesive is then applied from the roller 18 to the carrier material 1.
Reach the surface of 0. Subsequently, the carrier material 10 is
The first calender roller 12 is deflected from the initial horizontal direction to the vertical direction by the guide roller 21, and
Enter the passage slit between 13. Here, container 17
Flowable soft compounding material is supplied to the surface (adhesive coated or uncoated) of the carrier material. Subsequently, the carrier material, which is coated on one side with the soft compound material, is led to the subsequent guide roller 22 and introduced into the already mentioned furnace 16, in which the first layer of the applied soft compound material is introduced. Drying takes place. In this case, the single-sided coated carrier material 10 is supported by support rollers 23 as it passes through the furnace 16 .

After exiting the furnace 16 and being deflected twice by 90° in each case by guide rollers 24, the single-sided coated carrier material 10 enters a second adhesive coating device, which device components, for reasons of simplicity, are The same reference symbols as the adhesive supply devices 18 to 20 already described above are given. In this case, carrier material 1
Adhesive coating can be carried out on previously uncoated surfaces of 0. Thereafter, the carrier material 10 is again deflected from the horizontal direction to the vertical direction by the guide rollers 25 and then also by the second calender roller set 1 already mentioned above.
4, 15 and a carrier material 10 of flowable soft compounded material in a container 17 arranged thereon.
The other side (possibly with adhesive) is then coated.

What is important in this connection is the individual rollers 12, 1 of each calender roller set, the direction of which is indicated by arrows 26, 27 or 28, 29.
The circumferential velocities of 3 to 14 and 15 are different enough to apply a frictional force to the soft compound material.

The carrier material, now coated on both sides with soft compounding material, then enters the interior of the furnace 16 again via a subsequent guide roller 30. In this case, the drying of the recently applied soft compound coating and, of course, simultaneously the vulcanization of these two layers of soft compound material proceed at once. In order to use sufficient time for this, the path traveled by the coated carrier material in the furnace (its second path) is correspondingly lengthened by means of the three rollers 31 of relatively large diameter. will be taken into consideration.

Finally, after leaving the furnace 16, the finished carrier-reinforced web reaches a winding drum 33 via a subsequent guide roller 32.

The method of coating the carrier material 10, which has layers 34 or 35 of soft compound material on both sides, as described above with reference to the figures, consists in combining these two soft coating sheets 34,
35 subsequently manufactured from this web,
This makes it possible to adapt and implement flatpackings of different material compositions and/or different thicknesses to the respective load characteristics. In this case, for example,
The soft covering sheet 34 on one side of the carrier material 10 can be of a wear-resistant material composition. However, this is only an example of each possible composition of the soft covering sheet, and it is clear that the present invention is not limited thereto.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view schematically showing an embodiment of the apparatus for producing webs or plates according to the invention. 10...Carrier material, 12, 13 or 1
4, 15...Calendar roller set, 16...Drying-
and vulcanization furnace, 17... compounding material container, 18,1
9, 20... Adhesive supply device, 23... Support roller, 31... Large diameter guide roller, 33... Winding drum, 34, 35... Soft covering sheet.

Claims (1)

[Scope of Claims] 1. A carrier material in the form of a web or a plate, which carrier material is covered with a soft covering sheet of a soft compound material, in which case the soft compound material has a fibrous and optionally powdered base material. vulcanizable material and a binder, in which case the carrier material is formed into a flat plate, and the soft covering sheet is in the form of an asbestos-free powder of at least 80% of the 100% of the soft covering sheet. A web or plate consisting of a mineral substrate, approximately 6% of binder and up to 14% of asbestos-free fibers, in which the asbestos-free powdered mineral substrate consists of thermally and chemically untreated material. component and optionally an additional component consisting of a chemically and/or thermally treated material, characterized in that the ratio of treated material to untreated material is at most 25:55. web or plate reinforced by a carrier. 2. A carrier-reinforced web or plate according to claim 1, characterized in that the chemically and thermally untreated material is sheetrock powder. 3. A carrier-reinforced web or plate according to claim 1, characterized in that the chemically and thermally untreated material is mica. 4. characterized in that expanded graphite is used as chemically and thermally treated material,
A web or plate reinforced with a carrier according to any one of claims 1 to 3. 5. A carrier-reinforced web according to any one of claims 1 to 3, characterized in that expanded vermiculite is used as the thermally treated material; plate.