Product Name: Fluoroelastomer FKM

Peroxide curable FKM offer better chemical resistance due to the curing process, making them suited for more severe

GENERAL INTRODUCTION:

FKM is a family of fluorocarbon-based fluoroelastomer materials defined by ASTM International standard D1418,[1] and ISO standard 1629.[2] It is commonly called fluorine rubber or fluoro-rubber. FKM is an abbreviation of Fluorine Kautschuk Material.[3] All FKMs contain vinylidene fluoride as a monomer. Originally developed by DuPont (under the brand name Viton, now owned by Chemours), FKMs are today also produced by many companies, including: Daikin (Dai-El),[4] 3M (Dyneon),[5] Solvay S.A. (Tecnoflon),[6] HaloPolymer (Elaftor),[7] Gujarat Fluorochemicals (Fluonox),[8] and several Chinese manufacturers. Fluoroelastomers are more expensive than neoprene or nitrile rubber elastomers. They provide additional heat and chemical resistance.[9] FKMs can be divided into different classes on the basis of either their chemical composition, their fluorine content, or their cross-linking mechanism.

TYPES:

On the basis of their chemical composition FKMs can be divided into the following types:

Type-1 FKMs are composed of vinylidene fluoride (VDF) and hexafluoropropylene (HFP). Copolymers are the standard type of FKMs showing a good overall performance. Their fluorine content is approximately 66 weight percent.

Type-2 FKMs are composed of VDF, HFP, and tetrafluoroethylene (TFE). Terpolymers have a higher fluorine content compared to copolymers (typically between 68 and 69 weight percent fluorine), which results in better chemical and heat resistance. Compression set and low temperature flexibility may be affected negatively.

Type-3 FKMs are composed of VDF, TFE, and perfluoromethylvinylether (PMVE). The addition of PMVE provides better low temperature flexibility compared to copolymers and terpolymers. Typically, the fluorine content of type-3 FKMs ranges from 62 to 68 weight percent.

Type-4 FKMs are composed of propylene, TFE, and VDF. While base resistance is increased in type-4 FKMs, their swelling properties, especially in hydrocarbons, are worsened. Typically, they have a fluorine content of about 67 weight percent.

Type-5 FKMs are composed of VDF, HFP, TFE, PMVE, and ethylene. Known for base resistance and high-temperature resistance to hydrogen sulfide.[10]

Specification:(FKM RAW GUM-COPOLYMER)

Specification:(FKM RAW GUM-TERPOLYMER)

APPLICATIONS:

Because of their outstanding performance they find use in a number of sectors, including the following:

Chemical process and petroleum refining, where they are used for seals, pumps, gaskets and so on, due to their resistance to chemicals;

Analysis and process instruments: separators, diaphragms, cylindrical fittings, hoops, gaskets, etc.

Semiconductor manufacturing;

Food and pharmaceutical, because of their low degradation, also in contact with fluids;

Aviation and aerospace: high operating temperatures and high altitudes require superior heat and low-temperature resistance.[4]

They are suitable for the production of wearables, due to low wear and discoloration even during prolonged lifetimes in contact with skin oils and frequent exposure to light, while guaranteeing high comfort and stain resistance;[14]

The automotive industry represents their main application sector, where constant reach for higher efficiencies push manufacturers towards high-performing materials.[15] An example are FKM o-rings used as an upgrade to the original neoprene seals on Corvair pushrod tubes that deteriorated under the high heat produced by the engine, allowing oil leakage. FKM tubing or lined hoses are commonly recommended in automotive and other transportation fuel applications when high concentrations of biodiesel are required. Studies indicate that types B and F (FKM- GBL-S and FKM-GF-S) are more resistant to acidic biodiesel. (This is because biodiesel fuel is unstable and oxidizing.)[citation needed]

FKM O-rings have been used safely for some time in SCUBA diving by divers using gas blends referred to as nitrox. FKMs are used because they have a lower probability of catching fire, even with the increased percentages of oxygen found in nitrox. They are also less susceptible to decay under increased oxygen conditions.

While these materials have a wide range of applications, their cost is prohibitive when compared to other types of elastomers, meaning that their adoption must be justified by the need for outstanding performance (as in the aerospace sector) and is inadvisable for low-cost products.

FKM/butyl gloves are highly impermeable to many strong organic solvents that would destroy or permeate commonly used gloves (such as those made with nitriles).

Features & basic characteristics: 

1. Excellent flow ability and mold release
2. High tensile strength and anti-tearing property
3. Rapid curing process
4. Excellent agent resistance

Processing method & Applications

FKM can be used for products of vehicle fuel system, gasket and oil seal.