FLUOROCARBON RUBBER (FKM RUBBER) – ITS OVERVIEW …

1 PRODUCT DEVELOPMENT INFORMATIONVOLUME 2 ISSUE 11 MARCh 20131 of 7 FLUOROCARBON RUBBER (FKM RUBBER ) ITS OVERVIEW oils and solvents and unusually high chemical on the choice of the Rubbers, designated by FKM (earlier it was designated as FPM), is the SSSSSS specialised RUBBER , which are very stable, characterised by extreme Heat, Fire Resistance, Resistance to Oxidation, Ozone, swelling to As per the ASTM D2000/SAE J200 system of classification, FKM & FFKM (PerFlourinated FLUOROCARBON RUBBER ) occupies the top performance range, in the RUBBER category & is designated as HK for FKM & KK FKM RUBBER is made as Co-polymer, Ter-polymer and SSSSSSSSSSS special blends to meet the rigorous end requirements, PRODUCT DEVELOPMENT INFORMATIONVOLUME 2 ISSUE 11 MARCh 20132 of 7 Monomers being used for the manufacturing of FKM rubbers are as follows:And other monomers likef Ethylene (E)f Propylene(E)are also used for the special type of FKM RubberDepends on the combination of the monomers, different sub-type/sub-classification of FKM RUBBER is being manufactured world-wide, CO-POLYMERf TER-POLYMERf TER-POLYMER PEROXIDE CURABLEf SPECIAL LOW TEMPERATURE PEROXIDE CURABLEf BASE RESISTANTf PERFLUORO ELASTOMER FFKMB ased on the ASTM D1418, FKM RUBBER is classified as 5 types as follows.

2 TYPE 1CO-POLYMER OF Hexafluoropropylene & Vindylidenefluoride 3 HFP+VF2 TYPE 2 TER-POLYMER of Tetrafluoroethylene, vinylidenefluoride & hexafluoroprpylene 3 TFE+VF2+HFPTYPE 3 TER-POLYMER of Tetrafluoroethylene, fluorinated vinylether & vinylidenefluoride 3 TFE+PFMVE / PAVE+VF2 TYPE 4 TER-POLYMER of Tetrafluoroethylene, propylene & vinylidene fluoride 3 TFE+P+VF2 PENTA-POLYMER of Tetrafluoroethylene, hexafluoropropylene, TFE+HFP+VF2+E+PFMVE/PAVEf Vinylidene Fluoride (VF2) CH2=CF2f Hexa FluoroPropylene(HFP) CF2=CF-CF3f Tetra FluoroEthylene(TFE) CF2=CF2f PerFluoroMethyl Vinyl Ether(PFMVE)/ CF2=CF-O-CF3 PerfluoroAlkyl VinylEther(PAVE)f 1-HydroPentaFluoroPropylene(HPFP) CHF=CF-CF3f TriFluoroChloroEthylene(TFClE) CFCl=CF2 TYPE 5vinylidenefluoride, ethylene & a fluorinatedalkylvinylether 3 PRODUCT DEVELOPMENT INFORMATION3 of 7 VOLUME 2 ISSUE 11 MARCh 2013 For FFKM(PERFLUOROELASTOMER) the combination of the monomers are Tetrafluoroethylene, perfluoromethyl vinyl ether and a special cure-site monomer 3 TFE+PFMVE/PAVE+XFKM RUBBER is cured by Diamines, Bisphenol A/organophosphonium salt, Peroxide(only peroxide curable grades) and RUBBERS are available COMMERCIALLY as GUM Rubbers (Curatives needs to be added during compounding), Cure incorporated ones (only acid acceptors, fillers & processing aids need to be added), The commonly used ingredients are as follows:FILLER BLACKMT BLACK, FURNACE BLACK like SRF, FEF, HAF(at limited dosage), AUSTIN BLACK, conductive black, graphite.

3 FILLER-WHITEB arium Sulfate, Diatomaceous Silica, Calcium Meta silicate, , Rutile TiO2, calcium carbonate, ppt. Silica, micronized PTFE,..PROCESSING AIDSPETS, PE WAX, VEGETABLE WAX, Amine based, Zinc Stearate, Low volatile plasticisers are not used in FKM. Low molecular weight FKM in liquid form can be ACCEPTORSMgO, CaO, ZnO, Pb3O4 & with Ca(OH)2,CURING SYSTEM used in FKM RUBBER :Curing TypeCharacteristicsDIAMINE CURING SYSTEMG eneral purpose cure system BISPHENOL A / Organophosphonium saltFor Improved compression set resistance and most commonly used system peroxide curing type FKM, good resistance to acid, steam & amine based FFKMD epends on the curing point, following cure system is being used For Phenoxy group 3 Bisphenol AF For Bromine/Iodine 3 TAIC For CN group 3 Tin based via Triazine DEVELOPMENT INFORMATION4 of 7 VOLUME 2 ISSUE 11 MARCh 2013 POST-CURING OF FKM:All the grades of FKM needs to be post-cured and for peroxide based grades a post-curing of 4-8 hrs.

4 @ stabilisation of curing. Post-cure increases the heat stability of the RUBBER because during the post-curing cycle, heat-stable aromatic cross-links are formed and it will give good compression set resistance. Generally post curing is done at the temperatures of , 232 and 250 It is better to keep the products in the post curing cycle, by starting the oven temperature either from room temperature or from around 90 in a step of 20 25 , till the desired post curing temperature is reached, to achieve better properties in the FKM of FKM:In the high-temperature resistance and corrosive chemicals and hot-oil resistance requirements, also as a binder for powdered rocket fuels, insulators in the low-voltage & frequency applications, in Automotive, Aerospace, Chemical & Processing, Oil field/Mining, Semicon is sufficient & for other types of curing a minimum of 15/16 hr.

5 24 hr. curing cycle is essential for the PRODUCT DEVELOPMENT INFORMATION5 of 7 VOLUME 2 ISSUE 11 MARCh 2013 The Heat resistance of the FKM RUBBER is about 200 for continuous service, However, with increasing temperature the service life gets shortens approximately as follows:TEMPERATURESERVICE LIFE230 oC3000 GRADES OF TECNOFLON are as follows:Tecnoflon Bisphenol CurableTecnoflon Bisphenol CurablePRODUCT DEVELOPMENT INFORMATION6 of 7 VOLUME 2 ISSUE 11 MARCh 2013 TECNOFLON FKM & FFKM PRODUCT SELECTION GUIDE:PRODUCT DEVELOPMENT INFORMATION7 of 7 Ram Charan Company | Samson Tower, 403, L Pantheon Road, 6th Floor, Egmore, Chennai 600 008. Tamil Nadu, : +91 44 4353 9040 Fax : +91 44 4330 7050 Email : Website : | 098212 DelhiPuneBelgaumCoimbatoreVOLUME 2 ISSUE 11 MaRCH 2013 KINDLY NOTE: TECNOFLON IS MANUFACTURED BY M/S.

6 SOLVAY SOLEXIS.