EP0581893A1 - Industrial gasket for steam application - Google Patents

Industrial gasket for steam application

Info

Publication number
EP0581893A1
EP0581893A1 EP19920913319 EP92913319A EP0581893A1 EP 0581893 A1 EP0581893 A1 EP 0581893A1 EP 19920913319 EP19920913319 EP 19920913319 EP 92913319 A EP92913319 A EP 92913319A EP 0581893 A1 EP0581893 A1 EP 0581893A1
Authority
EP
European Patent Office
Prior art keywords
gasket
blend
fibers
pulp
polyaramid
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP19920913319
Other languages
German (de)
French (fr)
Inventor
Stavros Spiliadis
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
EIDP Inc
Original Assignee
EI Du Pont de Nemours and Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by EI Du Pont de Nemours and Co filed Critical EI Du Pont de Nemours and Co
Publication of EP0581893A1 publication Critical patent/EP0581893A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K3/00—Materials not provided for elsewhere
    • C09K3/10—Materials in mouldable or extrudable form for sealing or packing joints or covers
    • C09K3/1025—Materials in mouldable or extrudable form for sealing or packing joints or covers characterised by non-chemical features of one or more of its constituents
    • C09K3/1028—Fibres
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J15/00—Sealings
    • F16J15/02—Sealings between relatively-stationary surfaces
    • F16J15/06—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces
    • F16J15/10—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with non-metallic packing
    • F16J15/102—Sealings between relatively-stationary surfaces with solid packing compressed between sealing surfaces with non-metallic packing characterised by material
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K2200/00—Chemical nature of materials in mouldable or extrudable form for sealing or packing joints or covers
    • C09K2200/02—Inorganic compounds
    • C09K2200/0243—Silica-rich compounds, e.g. silicates, cement, glass
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K2200/00—Chemical nature of materials in mouldable or extrudable form for sealing or packing joints or covers
    • C09K2200/02—Inorganic compounds
    • C09K2200/0243—Silica-rich compounds, e.g. silicates, cement, glass
    • C09K2200/0252—Clays
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K2200/00—Chemical nature of materials in mouldable or extrudable form for sealing or packing joints or covers
    • C09K2200/02—Inorganic compounds
    • C09K2200/0243—Silica-rich compounds, e.g. silicates, cement, glass
    • C09K2200/0252—Clays
    • C09K2200/026—Kaolin
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K2200/00—Chemical nature of materials in mouldable or extrudable form for sealing or packing joints or covers
    • C09K2200/06—Macromolecular organic compounds, e.g. prepolymers
    • C09K2200/0607—Rubber or rubber derivatives
    • C09K2200/0612—Butadiene-acrylonitrile rubber
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K2200/00—Chemical nature of materials in mouldable or extrudable form for sealing or packing joints or covers
    • C09K2200/06—Macromolecular organic compounds, e.g. prepolymers
    • C09K2200/0615—Macromolecular organic compounds, e.g. prepolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • C09K2200/0635—Halogen-containing polymers, e.g. PVC
    • C09K2200/0637—Fluoro-containing polymers, e.g. PTFE
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K2200/00—Chemical nature of materials in mouldable or extrudable form for sealing or packing joints or covers
    • C09K2200/06—Macromolecular organic compounds, e.g. prepolymers
    • C09K2200/0692—Fibres
    • C09K2200/0695—Polyamide fibres

Definitions

  • This invention relates to industrial gaskets for steam applications and more particularly to such gaskets which are asbestos-free and manufactured by the calendering process using organic synthetic fibers, fillers and polymeric binders.
  • para-aramid pulp such as poly (g.-phenylene terephthalamide) pulp available commercially, has been steadily increasing as a replacement for asbestos.
  • Para-aramid pulp is a good material as a replacement because of its high temperature stability, strength and wear resistance.
  • Para-aramid pulp can be manufactured according to the process described in U.S. Patent 3,767,756. In this process, para-aramid filaments are mechanically converted into pulp by first cutting them into short fibers and then abrading them into pulp. This pulp is then used to make such products as brake linings, gaskets, laminates and composites.
  • an industrial gasket for steam applications consisting of a flexible sheet manufactured by the calendering process with organic synthetic fibers, fillers and polymeric binders characterized in that the organic fibers in the flexible sheet are a blend of (1) p_-polyaramid pulp and (2) at least one of (a) m -polyaramid staple or fibrids, and (b) polytetrafluoroethylene powder.
  • the drawing is an expanded scale graph showing water loss in percent versus days of testing.
  • Gaskets according to the present invention are flexible sheets manufactured according to the conventional calendering process for making compressed gaskets using calenders well-known to those skilled in the art.
  • the organic fibers which are used in these flexible sheets comprise a blend of (1) j . -polyaramid pulp (fibrillated fibers of variable length, usually averaging less than 12 mm in length) and (2) at least one of (a) m_-polyaramid short fibers (usually called staple or fibrids), and (b) polytetrafluoroethylene powders.
  • the blend of (1) to (2) has a weight ratio in the range of 99:1 and 50:50, preferably a weight ratio in the range of 99:1 and 80:20. It has been found surprisingly that when such blends are used to make gaskets by the calendering process that water lost through the gasket is very low when compared to conventional gaskets made by this process from asbestos and ji-polyaramid pulp alone.
  • Para-polyaramid pulp and m.-polyaramid fibers are well known and are sold commercially under the trademarks KEVLAR® and NOMEX® respectively by E.I. du Pont de Nemours & Co.
  • Para-polyaramid pulp can be prepared as described in EP-392 559-A2. It is preferred that a short fiber pulp of the blend useful in this invention be prepared by turbulent air grinding as described in U.S. Patent Application Ser.No. 07/506968, filed February 27, 1990, in the names of Haines and Schuler (KB-3040).
  • a blend of p.-polyaramid and m_-polyaramid can also be prepared as described in EP-392 559-A2 prior to the shredding procedure.
  • the fibrillated fibers in the pulp generally have a length of about 0.2 to 8 millimeters, preferably about 1 to 3 mm.
  • Polytetrafluoroethylene (PTFE) powder is a white free-flowing powder of submicron size particles. It is also available commercially under the trademark TEFLON® of E.I. du Pont de Nemours & Co. A useful PTFE powder has a bulk density from 300-600 g/1, preferably
  • SUBSTITUTE SHEET from 500-550 g/1, has an average particle size distribution on a volume basis of from 3-100 microns, and has a melt flow rate of 0.5- 50 g/10 minutes.
  • the PTFE powder is generally blended with the p_- polyaramid pulp prior to shredding.
  • An organic fiber blend as described above is made into a flexible sheet useful as a gasket for steam applications by mixing it with other materials known to be useful for gaskets and then forming the sheet by the well-known calendering process. This process can be carried out by using any of the calendering machines available commercially for this purpose.
  • fillers both organic and inorganic materials
  • polymeric binders include optional ingredients such as antioxidants, colorants, curing agents, and the like.
  • additional fibers can be included, e.g., inorganic silicate fibers.
  • inorganic filler materials are talc, barium sulfate, calcium carbonate, and wollastonite.
  • polymeric binders are preferred binders of rubber, e.g., nitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), natural rubber and ethylene propylene diene monomer rubbers (EPDM).
  • NBR nitrile butadiene rubber
  • SBR styrene butadiene rubber
  • EPDM ethylene propylene diene monomer rubbers
  • Compressed gaskets were prepared (about 2mm thick) using a blend of (1) 80% by weight rj-polyaramid pulp (KEVLAR® IF 356) having fiber lengths of 1-3 mm and 20% by weight m_-polyaramid staple short fibers (3-6 mm) and (2) 80% by weight p_-polyaramid pulp as above and 20% by weight of PTFE powder (TEFLON® MP1000).
  • gaskets were then compared in a steam test with a commercially available gasket of asbestos and one of p_-poly-aramid pulp alone (KEVLAR® IF356). All four gaskets were formulated with the same binder, fillers, and other ingredients such that the approximate gasket formulation was as follows: 15% weight % of blend (1), blend (2), asbestos, or p- polyaramid pulp;
  • NBR rubber 15% weight % of NBR rubber as a binder
  • inorganic fillers i.e. a mixture of talc, kaolin and silicate powder.
  • Each formulation contained about 1 weight % of a cross-linking agent and an antioxidant.
  • gasket A is blend (1) and gasket B is blend (2); gasket C is KEVLAR® pulp alone.
  • a stainless steel steam cell having a stainless steel cover with 6 calibrated bolts, and having a capacity of 0.08 liters is filled with about 70 grams of water.
  • the gasket under study is bolted between the flanges of the cell and cover to a bolt torque of l lkgm.
  • the completed system is placed in an air oven maintained at 240°C and is heated over a period of 3 hours so as to produce a predetermined internal water pressure of 32 bar.
  • the system is removed from the oven and allowed to cool at room temperature for three hours. This cycle is repeated for up to 40 days.
  • the cell is weighed and the water loss is measured with the total weight loss at the end of the test period being the water loss through the gasket.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Sealing Material Composition (AREA)
  • Gasket Seals (AREA)

Abstract

Joints utilisés dans des applications au contact de la vapeur et caractérisés par de faibles pertes d'eau à travers les joints lors de l'utilisation. Les joints sont des joints comprimés produits selon le processus de calandrage classique, ils utilisent une pulpe à mélange de fibres comme composants à fibres organiques à la place d'amiante ou d'autres fibres organiques présentes dans des joints classiques. Le mélange de fibres comprend (1) de la pulpe de p-polyaramide et (2) (a) des fibres discontinues ou des fibrides de m-polyaramide et/ou (b) de la poudre de polytétrafluoroéthylène.Seals used in applications in contact with steam and characterized by low water losses through the seals during use. The seals are compressed seals produced according to the conventional calendering process, they use a fiber blend pulp as organic fiber components in place of asbestos or other organic fibers present in conventional seals. The fiber blend includes (1) p-polyaramide pulp and (2) (a) staple fibers or fibrids of m-polyaramide and / or (b) polytetrafluoroethylene powder.

Description

TITLE OF INVENTION
INDUSTRIAL GASKET FOR STEAM APPLICATION
Background of the Invention
Field of Invention:
This invention relates to industrial gaskets for steam applications and more particularly to such gaskets which are asbestos-free and manufactured by the calendering process using organic synthetic fibers, fillers and polymeric binders.
Background Art:
Because of the health hazards associated with asbestos fibers, the industrial demand for para-aramid pulp, such as poly (g.-phenylene terephthalamide) pulp available commercially, has been steadily increasing as a replacement for asbestos. Para-aramid pulp is a good material as a replacement because of its high temperature stability, strength and wear resistance.
Para-aramid pulp can be manufactured according to the process described in U.S. Patent 3,767,756. In this process, para-aramid filaments are mechanically converted into pulp by first cutting them into short fibers and then abrading them into pulp. This pulp is then used to make such products as brake linings, gaskets, laminates and composites.
T Conventional gaskets are of many types and have many uses. In German Patent DE 3,735,634, soft gaskets for internal combustion engines are described which are made from para-aramid pulp and other materials using a conventional paper manufacturing process. Other patent references set forth in this German patent describe other combustion engine gaskets such as cylinder head gaskets. Such gaskets made by the paper manufacturing process are not suitable for use in steam applications, particularly in high pressure steam lines.
The use of fluoropolymers like polytetrafluoroethylene (PTFE) in gaskets is well known. Many citations can be found in the patent literature, which show the use of PTFE in various gasket materials. US patent 4 792 594 discloses the use of the described tetrafluoroethylene copolymer powders in gaskets.
Summary of the Invention
According to the present invention provided is an industrial gasket for steam applications consisting of a flexible sheet manufactured by the calendering process with organic synthetic fibers, fillers and polymeric binders characterized in that the organic fibers in the flexible sheet are a blend of (1) p_-polyaramid pulp and (2) at least one of (a) m -polyaramid staple or fibrids, and (b) polytetrafluoroethylene powder.
Brief Description of the Drawing
The drawing is an expanded scale graph showing water loss in percent versus days of testing.
SUBSTIT TE S ET Detailed Description of the Invention
Gaskets according to the present invention are flexible sheets manufactured according to the conventional calendering process for making compressed gaskets using calenders well-known to those skilled in the art. The organic fibers which are used in these flexible sheets comprise a blend of (1) j.-polyaramid pulp (fibrillated fibers of variable length, usually averaging less than 12 mm in length) and (2) at least one of (a) m_-polyaramid short fibers (usually called staple or fibrids), and (b) polytetrafluoroethylene powders. Generally, the blend of (1) to (2) has a weight ratio in the range of 99:1 and 50:50, preferably a weight ratio in the range of 99:1 and 80:20. It has been found surprisingly that when such blends are used to make gaskets by the calendering process that water lost through the gasket is very low when compared to conventional gaskets made by this process from asbestos and ji-polyaramid pulp alone.
Para-polyaramid pulp and m.-polyaramid fibers are well known and are sold commercially under the trademarks KEVLAR® and NOMEX® respectively by E.I. du Pont de Nemours & Co. Para-polyaramid pulp can be prepared as described in EP-392 559-A2. It is preferred that a short fiber pulp of the blend useful in this invention be prepared by turbulent air grinding as described in U.S. Patent Application Ser.No. 07/506968, filed February 27, 1990, in the names of Haines and Schuler (KB-3040). A blend of p.-polyaramid and m_-polyaramid can also be prepared as described in EP-392 559-A2 prior to the shredding procedure. The fibrillated fibers in the pulp generally have a length of about 0.2 to 8 millimeters, preferably about 1 to 3 mm.
Polytetrafluoroethylene (PTFE) powder is a white free-flowing powder of submicron size particles. It is also available commercially under the trademark TEFLON® of E.I. du Pont de Nemours & Co. A useful PTFE powder has a bulk density from 300-600 g/1, preferably
SUBSTITUTE SHEET from 500-550 g/1, has an average particle size distribution on a volume basis of from 3-100 microns, and has a melt flow rate of 0.5- 50 g/10 minutes. The PTFE powder is generally blended with the p_- polyaramid pulp prior to shredding.
An organic fiber blend as described above is made into a flexible sheet useful as a gasket for steam applications by mixing it with other materials known to be useful for gaskets and then forming the sheet by the well-known calendering process. This process can be carried out by using any of the calendering machines available commercially for this purpose.
Other materials useful in making gaskets are fillers (both organic and inorganic materials), polymeric binders, and optional ingredients such as antioxidants, colorants, curing agents, and the like. Up to 10 weight % of additional fibers can be included, e.g., inorganic silicate fibers. Examples of inorganic filler materials are talc, barium sulfate, calcium carbonate, and wollastonite. Examples of polymeric binders are preferred binders of rubber, e.g., nitrile butadiene rubber (NBR), styrene butadiene rubber (SBR), natural rubber and ethylene propylene diene monomer rubbers (EPDM).
E x a m l e s
Compressed gaskets were prepared (about 2mm thick) using a blend of (1) 80% by weight rj-polyaramid pulp (KEVLAR® IF 356) having fiber lengths of 1-3 mm and 20% by weight m_-polyaramid staple short fibers (3-6 mm) and (2) 80% by weight p_-polyaramid pulp as above and 20% by weight of PTFE powder (TEFLON® MP1000).
The gaskets were then compared in a steam test with a commercially available gasket of asbestos and one of p_-poly-aramid pulp alone (KEVLAR® IF356). All four gaskets were formulated with the same binder, fillers, and other ingredients such that the approximate gasket formulation was as follows: 15% weight % of blend (1), blend (2), asbestos, or p- polyaramid pulp;
15% weight % of NBR rubber as a binder;
70% weight % of inorganic fillers (i.e. a mixture of talc, kaolin and silicate powder).
Each formulation contained about 1 weight % of a cross-linking agent and an antioxidant. In Table I which follows, gasket A is blend (1) and gasket B is blend (2); gasket C is KEVLAR® pulp alone.
Steam Test:
A stainless steel steam cell having a stainless steel cover with 6 calibrated bolts, and having a capacity of 0.08 liters is filled with about 70 grams of water. The gasket under study is bolted between the flanges of the cell and cover to a bolt torque of l lkgm. The completed system is placed in an air oven maintained at 240°C and is heated over a period of 3 hours so as to produce a predetermined internal water pressure of 32 bar. The system is removed from the oven and allowed to cool at room temperature for three hours. This cycle is repeated for up to 40 days. At the end of a cycle, the cell is weighed and the water loss is measured with the total weight loss at the end of the test period being the water loss through the gasket.
The percent water loss for each test gasket (an average of 4 tests) is shown in Table I. In addition, water loss was plotted on an expanded scale in order to be able to show the low water loss for gaskets of the invention (A and B) relative to a commercial gasket of asbestos and KEVLAR® pulp (C). T A B L E I
Total Water Loss (%\ Davs
3 5 7 10 12 14 17 38
Sample No.
A 0.56 0.56 0.56 0.56 0.56 0.86 0.60 1.20
B 0.61 0.72 0.72 0.78 0.78 1.04 1.15 1.61
C 2.7 4.3 6.0 8.1 9.6 11.2 13.3 27.6
Asbestos 11.4 20.1 23.2 36.6 48.4 61.1 84.7 100

Claims

WHAT IS CLAIMED IS:
1. An industrial gasket for steam applications consisting of a flexible sheet manufactured by the calendering process with organic synthetic fibers, fillers, and polymeric binders characterized in that the organic fibers in the flexible sheet are a blend of (1) p_-polyaramid pulp and (2) at least one of (a) m_- polyaramid staple or fibrids, and (b) polytetrafluoroethylene powder.
2. A gasket of Claim 1 characterized in that the weight ratio of (1) to (2) in the blend is within the range of 99:1 and 50:50.
3. A gasket of Claim 1 or Claim 2 characterized in that the blend is of p_-polyaramid pulp and m_-polyaramid fibers in the form of short fibers in a weight ratio of 99:1 and 80:20.
4. A gasket of Claim 1 or Claim 2 characterized in that the blend is of p_-polyaramid pulp and polytetrafluoroethylene powder in a weight ratio of 99:1 and 80:20.
5. A gasket according to any of Claims 1 to 4 characterized in that the flexible sheet contains up to 10 weight % of additional fibers.
6. A gasket according to any of Claims 1 to 5 characterized in that the fibers in the blend have a length in the range of 0.2 to 12 mm .
A gasket according to any of Claims 1 to 6 characterized in that the flexible sheet consists essentially of
(a) 5-20 weight % of the blend of organic fibers;
SUBSTITUTE SHEET (b) 60-85 weight % of at least one inorganic material; and
(c) 10-20 weight % of a rubber polymeric binder.
A gasket according to any of Claims 1 to 7 characterized in that the blend of organic fibers is prepared by turbulent air grinding.
EP19920913319 1991-04-23 1992-04-03 Industrial gasket for steam application Withdrawn EP0581893A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4113153 1991-04-23
DE19914113153 DE4113153A1 (en) 1991-04-23 1991-04-23 INDUSTRIAL SEAL FOR USE WITH STEAM

Publications (1)

Publication Number Publication Date
EP0581893A1 true EP0581893A1 (en) 1994-02-09

Family

ID=6430134

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19920913319 Withdrawn EP0581893A1 (en) 1991-04-23 1992-04-03 Industrial gasket for steam application

Country Status (4)

Country Link
EP (1) EP0581893A1 (en)
JP (1) JPH06507196A (en)
DE (1) DE4113153A1 (en)
WO (1) WO1992018578A1 (en)

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DE4333880C2 (en) * 1993-10-05 2003-03-06 Sms Demag Ag roller bearing
AU702352B2 (en) * 1994-08-09 1999-02-18 Sterling Chemicals International, Inc. Asbestos-free gaskets and the like containing blends of organic fibrous and particulate components
IN183563B (en) * 1994-08-09 2000-02-12 Sterling Chemicals Internat In
US5520866A (en) * 1994-08-09 1996-05-28 Cytec Technology Corp. Process for the preparation of friction materials containing blends of organic fibrous and particulate components
EP0696693B1 (en) * 1994-08-09 1999-07-07 Sterling Chemicals International, Inc. Dry processed friction material, method of making same, and dry blend
GB2314569B (en) * 1996-06-27 2000-01-26 T & N Technology Ltd Gasket paper
DE19703675A1 (en) * 1997-01-31 1998-08-06 Siemens Ag Sealing part for housing for application in automobiles, fuse boxes, distributor boxes
WO2001033116A1 (en) * 1999-11-05 2001-05-10 Robert Bosch Gmbh Dry method for the manufacturing of asbestos free sealant for fuel injection pump
DE10128346A1 (en) * 2001-06-13 2003-03-06 Freudenberg Carl Kg Flat gasket and process for its manufacture
DE10347080A1 (en) * 2003-10-10 2005-05-12 Frenzelit Werke Gmbh & Co Kg Flat sealing material in the form of a fiber-reinforced foil
GB2534199A (en) 2015-01-16 2016-07-20 Henkel IP & Holding GmbH Sealant material
CN107814992B (en) * 2017-12-14 2019-10-25 山东科技大学 A kind of the rubber product sizing material and preparation method of the heat-resisting system of hydrogenated nitrile-butadiene rubber

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DE3735634A1 (en) * 1987-10-21 1989-05-03 Goetze Ag Flexible gasket material, in particular for cylinder-head gaskets
WO1990007664A1 (en) * 1989-01-09 1990-07-12 J.M. Clipper Corporation Annular seal
US5094913A (en) * 1989-04-13 1992-03-10 E. I. Du Pont De Nemours And Company Oriented, shaped articles of pulpable para-aramid/meta-aramid blends

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Title
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Also Published As

Publication number Publication date
JPH06507196A (en) 1994-08-11
WO1992018578A1 (en) 1992-10-29
DE4113153A1 (en) 1992-10-29
DE4113153C2 (en) 1993-04-15

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