Flexible graphite is a soft sheet form of compressed natural graphite made from exfoliated mineral flake(crystalline) graphite. Due to its flexible texture, it is referred to as flexible graphite to distinguish it from other forms of graphite materials: flake graphite, amorphous graphite, artificial graphite (hard graphite), graphite electrodes, graphite/carbon fiber, etc.

　　standard flexible graphite sheet product suitable for most industry applications. As gasket material, it is usually fabricated into Graphite Laminate, reinforced graphite sheet and widely used in fluid sealing applications: flange gasket, spiral wound gasket, heat exchanger gasket, etc. It can also be used as solid lubricant in metal stamping and forming applications, or as heat liner in industry furnaces and other heating devices.

　　Sometimes flexible graphite is also referred to by a manufacturer's brand name like grafoil. Flexible graphite sheet is made with pure expanded graphite. standard flexible graphite sheet product has a high purity of 99.0% carbon content. Higher carbon content gives the flexible graphite foil better chemical resistance, better thermal conductivity, and better sealing ability.

　　graphite gasket sheet is made with pure flexible graphite sheet reinforced with glass fiber insert. The both sides are pure graphite sheet, the reinforced material is one layer or two layers of glass fiber. The graphite layer and glass fiber are jointed together with glue bonded. Reinforced graphite gasket is cut or molded from our reinforced graphite sheets. Inner and outer eyelet with SS304 or SS316.

　　Graphite gaskets having excellent corrosion resistance, high temperature resistance, excellent compressibility and recovery, widely used for piping, valves, pumps, pressure vessels, heat exchangers, condensers, generators, compressed machine, exhaust pipes, chillers. Graphite reinforced gasket can also cut into any shape of complex gaskets such as water gauge gasket, full face flange gasket and automotive cylinder head gasket.

　　Reinforced materials: stainless steel tanged, stainless steel foil, tinplate, wire mesh, glass fiber and and Aluminium foil.

　　Flexible graphite sheet is light weight and easy to make,the price is much lower.it’s a suitable material to set fluid.this rechargeable battery,with a polyaniline anode and zinc negative pole,and a graphite sheet set fluid,has a reasonable price,large specific area,light weight,easy to use and no pollution to environment.

　　Because of the almost same structure between flexible graphite sheet and natural graphite sheet,so the flexible graphite sheet has a similar property with natural graphite.however,as to the different processing from natural graphite ,so the flexible graphite sheet has some special properties that natural one do not have,such like :high temperature resistance,radiation resistance,chemical erosion resistance,lubrication,sealing,mechanical,easy to mold,etc.Graphite resource is rich in our country,so the development and search of graphite material has a very important significance.

　　Flexible graphite material is made of natural flake graphite ,flake graphite and intercalation agent will have a reaction,and to be the expandable graphite ,after high temperature pressing ,the graphite sheet will be done.

　　The flexible graphite could be used not only in the sealing but fuel cell industry.flexible graphite has a good thermal conductivity and airtightness,so it can meet the requirement of fuel cell industry.

　　Flexible graphite sheet was invented in the late last century,at first,it’s used to solve the problem about the atomic energy valve leakage,the flexible graphite sheet is most suitable for this using,no cotton of the automotive industry promotes the development of graphite sheet industry,the flexible graphite sheet solved the problem of cotton material that leakage less than half one year,and reduce the cost.the prospects of flexible graphite material will be more and more broad.

Low density carbon/graphite material has a good physical and chemical properties, in recent years,the study on the low density graphite material is very active.The expanded graphite block made of flexible graphite sheet,is also one kind of the low density graphite material.

　　The method to make the expanded graphite block can be simply describe as below:

　　Make the flexible graphite sheet dipped in the concentrated sulfuric acid and concentrated nitric acid,then,under the situation of 200℃～750℃ to make the expanded graphite block.

　　The intercalator,dipping time,shape of the flexible graphite sheet and the operating temperature all have an influence on the density and shape integrity of the expanded graphite block.

　　The density will be lower with the rise of operating temperature, but the shape of the block is harder to complete.during the experiment,we could use the flexible graphite sheet or flexible graphite plate.

　　The picture showing is the appearance of expanded graphite blocks obtained with different extemal dimensions of flexible graphite sheet.And the intercalator isconcentrated sulfuric acid. From the picture,we can tell apparently that different shape of the graphite sheet has a big influence on the shape of the expanded graphite block.

　　The shape of the expanded graphite block also has a relationship with the temperature,when the temperature are 550℃~700℃,the density of the block can change stablely,and when the temperature exceed 700℃, the fracture failure rate will sharp rise,and appear different degree of the fracture.

　　The expanded graphite block has two typical appearance,one is uniform appearance and another one is non uniform appearance.

　　Research and development on the low carbon content graphite sheet is one area of graphite sealing material. Actually,to some instruments such as farm equipment , extensive chemical machinery,it’s no need to use the high carbon content flexible graphite sheet.it’s enough that If the sealing property could be better than the asbestine,and under this situation,it could reduce costs and selling price,and it also could promote the replace of flexible graphite sheet.

　　As per the process flow:

　　Expandable graphite > High temperature expansion > Pre press > Thermal treatment > molded press > Further repression,the expandable graphite could be process to the graphite sheet.

　　According to the study showing that,the appropriate reduction of the carbon content could totally satisfied to the seal requirements of general industrial seals. Mainly from the following aspects to characterize:

　　1) The infulance to the mechanical property of carbon content and impurity.

　　Demonstrated by the experiment,the intensity and purity of graphite sheet are proportional,under the situation of low carbon content,the tensile strength is inversely proportional to carbon content,apparently,the impurity has an important influence to the mechanical property.

　　2) The infulance to the air tightness of carbon content and impurity.

　　Use the gaskets made of the flexible graphite sheet to do the air tightness test,and the results showed that the leakage rate has little relationship with the carbon content,with the increase of the carbon content,the change of the sealing properity is not obvious,and all the testing samples could meet the German flexible graphite gasket gas tightness requirements,in addition,the impurity also has a little influence with the leakage rate.

　　The influence of the carbon content is not obvious,and still could maintain the good sealing property,however,the price will be fall by 50%.

The flexible graphite sheet is widely used as an engineering material because of its excellent sealing effect.the main advantage and disadvantage described below:

The advantage:

　　1)high thermal conductivity

　　The high thermal conductivity of flexible graphite sheet is much higher than PTFE and asbestos,

　　During the motive seal,the excellent thermal conductivity could sweep away the heat caused by friction.and avoid the temperature too high.

　　2)self-lubrication

　　The flexible graphite sheet is made of flake graphite,as the layered structure,it has a good property of self-lubrication.during the work time, the lamellar orientation parallel to the direction of friction,and combining power between layers is very low,and the crystal is easy to move,so the friction coefficient is very low. During the operation of the equipment,it could form a film on the surface of the metal after about 20min,and after that,the friction will only happen between the crystals instead of the metal and crystal.

The disadvantage:

　　1) the low tensile strength and flexural strength

　　Compared with other sealing materials,the tensile strength and flexural strength is lower than them,and it’s really an obvious disadvantage of the flexible graphite sheet.and it’s also lack of toughness,so the flexible graphite sheet is not suitable for sealing parts as lip,and forming packing.

　　2)the heat loss of the flexible graphite sheet.

　　The flexible graphite sheet is same as the ordinary graphite products at those property of high temperature oxidation,at about 550℃,the graphite start to oxidate,if this situation lasts long time,the accumulative total of the heat loss is very obvious.

　　to sum up,although the flexible graphite sheet is widely used as sealing ,but it still has some problem to improve,and the flexible graphite composite material is a good way to solve it,such as spiral wound gasket and adding the ceramics,Al2O3,Si3N4 and Si.so the temperature will be increase to 1260℃.

　　Flexible graphite is a soft sheet form of compressed natural graphite made from exfoliated mineral flake(crystalline) graphite. Due to its flexible texture, it is referred to as flexible graphite to distinguish it from other forms of graphite materials: flake graphite, amorphous graphite, artificial graphite (hard graphite), graphite electrodes, graphite/carbon fiber, etc. Sometimes flexible graphite is also referred to by a manufacturer's brand name like grafoil. Flexible graphite sheet is made with pure expanded graphite. standard flexible graphite sheet product has a high purity of 99.0% carbon content. Higher carbon content gives the flexible graphite foil better chemical resistance, better thermal conductivity, and better sealing ability.

　　Standard flexible graphite sheet product suitable for most industry applications. As gasket material, it is usually fabricated into Graphite Laminate, reinforced graphite sheet and widely used in fluid sealing applications: flange gasket, spiral wound gasket, heat exchanger gasket, etc. It can also be used as solid lubricant in metal stamping and forming applications, or as heat liner in industry furnaces and other heating devices.

　　Graphite gasket sheet is made with pure flexible graphite sheet reinforced with glass fiber insert. The both sides are pure graphite sheet, the reinforced material is one layer or two layers of glass fiber. The graphite layer and glass fiber are jointed together with glue bonded. Reinforced graphite gasket is cut or molded from our reinforced graphite sheets. Inner and outer eyelet with SS304 or SS316.

　　Graphite gaskets having excellent corrosion resistance, high temperature resistance, excellent compressibility and recovery, widely used for piping, valves, pumps, pressure vessels, heat exchangers, condensers, generators, compressed machine, exhaust pipes, chillers. Graphite reinforced gasket can also cut into any shape of complex gaskets such as water gauge gasket, full face flange gasket and automotive cylinder head gasket.

　　Reinforced materials: stainless steel tanged, stainless steel foil, tinplate, wire mesh, glass fiber and and Aluminium foil.

　　 Flexible graphite sheet is wildly used in all kinds of industry field. Flexible graphite roll uses: composite panels, cylinder head gaskets, packing, and so made ​​manufacturing gaskets, sealing elements such as static gauge, mold, flange gasket. Attached to a variety of metal surfaces, improving sealing performance. Flexible graphite sheet / plate, after high purity natural flake graphite by chemical and heat treatment, made ​​of molded rolling, without any binder. In the harsh working conditions still has excellent sealing performance, long life, low maintenance costs.

　　Character and Appearance: black with metallic luster, high dispersion, never bonded graphite powder. Touch greasy feel can heat and good thermal stability, rich conductivity, thermal conductivity, chemical stability, acid and alkali plasticity and organic solvents, corrosion, and has outstanding lubricity.

　　Main purpose:

　　1: Powder metallurgy and metal alloy materials of carbon

　　2: Seal Manufacturing (high temperature, high pressure washer machine and even oil)

　　3: Base material for high temperature lubrication, corrosion-resistant lubricating base

　　Characteristics and Specs：

• 　　Heat and fire resistant
• 　　Chemical resistant, compatible with most chemicals
• 　　Compressible, conformable, low creep relaxation
• 　　Thermal conductive, electrical conductive
• 　　Reinforced structure to handle high pressure applications

　　Working Temperature Range:

　　Oxidizing Atmosphere, such as air: -400° F to 950° F (-240°C to 510°C)

　　Mild Oxidizing Atmosphere of most gasket applications: -400° F to 1500° F(-240°C to 850° C)

　　Non-Oxidizing Atmosphere: -400° F to 5400° F (-240°C to 3000° C)

　　Thermal Conductivity:

　　Parallel to Sheet Surface: 960 BTU-in/ft2.h.F (140 W/m.K)

　　Through Thickness: 36 BTU.in/ ft2.h.F (5W/m.K)

　　Graphite reinforced gasket can also cut into the shape of complex gaskets such as water gauge pads, punching flange gasket and automotive diesel engine cylinder gasket. High strength gasket is pure cut gasket improvements inner coated metal foil, namely to maintain the excellent performance of the original gasket, and easy installation, removal, not damaged, but also to prevent the erosion of the gasket medium improve the pressure, and has good corrosion resistance, high / low temperature, good compression resilient and high strength gasket forms: ordinary type, stainless steel edging type. Material and Structure: Flexible graphite sheet material and the metal plate moved sprint composite molding. Temperature: -200 ° C ~ 600 ° C operating pressure: 20MPa main purposes: for a variety of media machines, static seal pumps, pipes, valves, flanges and other equipment.

　　　　Variety: flexible graphite sheet, flexible graphite sheet, flexible graphite strip.

　　Performance: high temperature, low temperature, corrosion resistance to various media, self-lubricating performance, low coefficient of friction, unique flexibility and resilience.

　　1.For rubber, plastic filler to improve wear resistance and compressive properties of plastic or wood made ​​of conductive

　　2.Anti-static, anti-corrosion coating

　　3.Flexible and conformable nature

　　4.Chemical resistant, compatible with most corrosive chemicals

　　5.Heat and flame resistant

　　6.Thermal conductive, electrical conductive

　　7.Low creep relaxation and no aging

　　Usage: graphite easy to damp, with the completion of the Energizer sealed to prevent contamination of the powder station junction or.

　　Flexible graphite sheet is wildly used in all kinds of industry field. Flexible graphite roll uses: composite panels, cylinder head gaskets, packing, and so made ​​manufacturing gaskets, sealing elements such as static gauge, mold, flange gasket. Attached to a variety of metal surfaces, improving sealing performance. Flexible graphite sheet / plate, after high purity natural flake graphite by chemical and heat treatment, made ​​of molded rolling, without any binder. In the harsh working conditions still has excellent sealing performance, long life, low maintenance costs.

　　Character and Appearance: black with metallic luster, high dispersion, never bonded graphite powder. Touch greasy feel can heat and good thermal stability, rich conductivity, thermal conductivity, chemical stability, acid and alkali plasticity and organic solvents, corrosion, and has outstanding lubricity.

　　Main purpose:

　　1: Powder metallurgy and metal alloy materials of carbon

　　2: Seal Manufacturing (high temperature, high pressure washer machine and even oil)

　　3: Base material for high temperature lubrication, corrosion-resistant lubricating base