# US 2003/0132579 A1 · Gaskets

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- Number: US 2003/0132579 A1
- Document ID: US20030132579A1
- Status: Published application
- Kind: A1
- Application number: 10/181,116
- Filed: 2002-10-03
- Published: 2003-07-17
- Earliest claimed: 2000-01-14
- Assignees: Flexitallic Limited
- Inventors: John Robert Hoyes; Stephen Woolfenden
- Web page: https://patentgrep.com/patent/US20030132579A1

## CPC

- F16J 15/125: {generally perpendicular to the surfaces}
- C04B 30/00: Compositions for artificial stone, not containing binders
- F16L 23/18: the sealing means being rings
- F16J: PISTONS {(specially adapted for dampers F16F9/32)}; CYLINDERS; SEALINGS
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE
- F16L: PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL

## Abstract

A spirally wound gasket is described. The gasket includes a sealing strip (11) wound into a spiral and a support strip (10) wound into a spiral in such a manner that the spiral of the sealing strip is formed interposed between the coils of the supporting strip. The sealing strip comprises a resilient material, the resilient material comprising a CEV component in a proportion of at least 25% w/w of the sealing strip. The CEV component is at least partially derived from dry CEV, and the sealing strip does not include a carrier strip in one aspect. In another aspect, the CEV component is at least partially derived from dry CEV, and the sealing strip has a moisture level of between 3-20% w/w of the sealing strip resilient material during winding into the said gasket. A method of producing a sealing strip is also described.

## Claims

### Claim 1

A spirally wound gasket comprising a sealing strip wound into a spiral and a support strip wound into a spiral in such a manner that the spiral of the sealing strip is formed interposed between the coils of the supporting strip, the sealing strip comprising a resilient material, the resilient material comprising a chemically exfoliated vermiculite (CEV) component in a proportion of at least 25% w/w of the sealing strip, the said CEV component being at least partially derived from dry CEV, wherein the sealing strip does not include a carrier strip.

### Claim 2 (depends on 1)

A spirally wound gasket according to claim 1, wherein the resilient material also comprises a hydrolysis resistant polymer to improve the water resistance of said sealing strip, the proportion of the said polymer not exceeding 20% w/w of the sealing strip.

### Claim 3 (depends on 1, 2)

A spirally wound gasket according to claim 1 or 2, wherein the resilient material further comprises a plate like filler material.

### Claim 4 (depends on 1, 2, 3)

A spirally wound gasket according to claim 1, 2 or 3, wherein the sealing strip has a small moisture content during spiral winding.

### Claim 5

A spirally wound gasket according to any preceding claim, wherein the sealing strip has a small moisture content during removal from a forming sheet on which the sealing strips or layers are formed.

### Claim 6

A spirally wound gasket according to any preceding claim, wherein the proportion of CEV is at least 30% w/w of the sealing strip.

### Claim 7

A spirally wound gasket according to any preceding claim, wherein the level of CEV falls within the range 25-80% w/w of the sealing strip

### Claim 8 (depends on 2, 3, 4, 5, 6, 7)

A spirally wound gasket according to any of claims 2-7, wherein the proportion of the said polymer is less than 15% w/w of the sealing strip.

### Claim 9

A spirally wound gasket according to any preceding claim, wherein the chemically exfoliated vermiculite component of the present invention includes sufficient dry CEV, to provide a wet sealing layer dough with a reduced water content which is capable of being dried before substantial skinning has occurred.

### Claim 10

A spirally wound gasket comprising a sealing strip wound into a spiral and a support strip wound into a spiral in such a manner that the spiral of the sealing strip is formed interposed between the coils of the supporting strip, the sealing strip comprising a resilient material, the resilient material comprising a CEV component in a proportion of at least 25% w/w of the sealing strip, the said CEV component being at least partially derived from dry CEV, wherein the sealing strip has a moisture level of between 3-20% w/w of the sealing strip resilient material during winding into the said gasket.

### Claim 11 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9)

A spirally wound gasket according to any of claims 1-9, wherein the moisture level of the sealing strip during winding is between 2-10% w/w of the resilient material of the sealing strip.

### Claim 12

A spirally wound gasket according to any preceding claim, wherein the sealing strip comprises at least 80% resilient material.

### Claim 13 (depends on 10)

A spirally wound gasket according to claim 10, wherein the sealing strip includes a carrier strip.

### Claim 14

A method of producing a sealing strip for a spirally wound gasket in accordance with any preceding claim comprising the steps of:
(a) the application of a wet sealing strip material to a forming sheet to form a layer,
(b) partially drying the said wet sealing strip layer on the forming sheet,
(c) removing the layer from the forming sheet, and
(d) cutting the layer into strips suitable for use in the formation of a spirally wound gasket.

### Claim 15 (depends on 14)

A method according to claim 14, wherein the solids content of the wet sealing strip material prior to the drying step is in the range 20-70% w/w of the material.

### Claim 16 (depends on 13, 14)

A method according to claim 13 or 14, wherein step (c) is carried out after step (d).

### Claim 17 (depends on 14, 15, 16)

A method according to any of claims 14-16, wherein the solids content of the said sealing strip layer is in the range 25-60% w/w of the wet material.

### Claim 18

A gasket or method according to any preceding claim, wherein the CEV is mixed with a suitable plate-like filling agent such as thermally exfoliated vermiculite (TEV).

### Claim 19 (depends on 18)

A gasket or method according to claim 18, wherein the filling agent comprises less than 75% w/w of the sealing strip.

### Claim 20 (depends on 5, 14, 15, 16, 17, 18, 19)

A method according to any of claims 14-19 or a gasket according to claim 5, wherein the water content of the partially dried layer during removal from the forming sheet is 3-20% w/w.

### Claim 21 (depends on 14, 15, 16, 17, 18, 19, 20)

A method according to any of claims 14-20, wherein a further drying step may be carried out after removal of the sealing layer material from the forming layer.

### Claim 22 (depends on 14, 15, 16, 17, 18, 19, 20, 21)

A method according to any of claims 14-21, wherein the wet sealing strip layer material dough is dried at temperatures between 50-135° C.

### Claim 23 (depends on 14, 15, 16, 17, 18, 19, 20, 21, 22)

A method according to any of claims 14-22, wherein the wet sealing strip material is spread onto the forming sheet using a suitable spreading technique such as the application of a doctor blade.

### Claim 24 (depends on 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)

A method according to any of claims 14-23, wherein the wet sealing strip material is in the form of a spreadable paste.

### Claim 25 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 17, 18, 19, 20)

A gasket according to any of claims 1-13 or 17-20, wherein the relative ratio of non-dry derived CEV to dry CEV in the dried sealing strip component is between 0.01:1 and 20:1.

### Claim 26 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 17, 18, 19, 20, 25)

A gasket according to any of claims 1-13, 17-20 or 25, wherein the particle size of at least a substantial proportion, at least 90% for example, of the CEV is more than 50 μm.

### Claim 27 (depends on 14, 15, 16, 18, 19, 20, 21, 22, 23, 24)

A method according to any of claims 14-16 or 18-24, wherein the CEV component in the wet material comprises a mixture of dried CEV and CEV in a slurry form.

### Claim 28 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 17, 18, 19, 20, 25, 26)

A gasket according to any of claims 1-13 or 17-20, 25 or 26, wherein the resilient material is mechanically bonded to the support strip.

### Claim 29 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 17, 18, 19, 20, 25, 26, 28)

A gasket according to any of claims 1-13, 17-20, 25, 26 or 28 which includes, as a plate-like filler, vermiculite material with a plate size substantially, for example at least 90%, in the range 50-300 μm.

### Claim 30 (depends on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 17, 18, 19, 20, 25, 26, 28, 29)

A gasket according to any of claims 1-13, 17-20, 25, 26, 28 or 29, wherein the sealing layer comprises 5-80% plate like filler in the dried sealing layer.

### Claim 31

A gasket as hereinbefore described with reference to the drawings.

### Claim 32

A method of making a gasket as hereinbefore described with reference to the drawings.