Nkawom 
Nsɔano adwumayɛ ne ɔsom asetra a ɛwɔ . O-rings . Ɛgyina dimensional accuracy ne compound quality so, hwehwɛ compounds a ɛwɔ mfiri ahoɔden pa, nusu a ɛko tia, ɔhyew ne ngo a ɛko tia, ne compression set a ɛba fam. Nneɛma a wɔtaa de di dwuma ne nitrile rɔba (NBR), a ɛfata ma nneɛma a wɔde di dwuma wɔ ɔkwan a ɛkɔ so wɔ ngo so nyinaa; acrylic rɔba (ACM), a ɛyɛ hyew a etumi gyina ano kosi 150–190°C; fluorocarbon rɔba . (FKM) ne silicone rɔba (VMQ) ma mmeae a ɛhɔ yɛ hyew kɛse.
Wɔ adwumayɛ nhyɛso a ɛkɔ soro mu no, wobetumi de carbon black aka ho na ama ayɛ den, nanso dodow a ɛboro so no betumi ama ɔhaw ahorow a ɛfa nneɛma a wɔyɛ ho ne adwumayɛ a wɔsɛe no aba. Sɛnea ɛbɛyɛ a ɔhyew ne ngo a wɔko tia no bɛyɛ kɛse bere a ɛtew nhyɛso a ɛwɔ so no so no, wobetumi de peroxide curing (sɛ nhwɛso no, DCP) anaasɛ sulfur nhyehyɛe a etu mpɔn (a ɛba fam sulfur, accelerator a ɛkorɔn) adi dwuma de ayɛ carbon-carbon nkitahodi a ɛyɛ den ne disulfide crosslink nhyehyɛe ahorow.
Ɛsɛ sɛ nhyehyɛe ahorow a ɛhyɛ den di dwuma de coarse-patwerɛ, low-activity fillers te sɛ thermal cracking carbon black anaasɛ carbon black a wɔde petepete so di dwuma de hwɛ hu sɛ ɛyɛ den kɛse, ɔhyew a ɛba fam, ne nhyɛso a ɛba fam koraa, bere a wɔma kwan ma wɔde adesoa kɛse ba ma ɛka a wɔbɔ no so tew. Dynamic sealing wes betumi de carbon black bi a ɛko tia abrasion a ɛkorɔn aka ho. Fluorocarbon rɔba da nneɛma a ɛma ɛyɛ den sɛ ɛbɛhyɛ ne ho so adi, na ɛhwehwɛ sɛ ɛyɛ mmerɛw kakraa bi pɛ . Carbon tuntum . ; ; Nneɛma dodow a ɛboro so no sɛe mfiridwuma mu nneɛma.
Nsɔano adwumayɛ ne ɔsom asetra a ɛwɔ . O-rings . Ɛgyina dimensional accuracy ne compound quality so, hwehwɛ compounds a ɛwɔ mfiri ahoɔden pa, nusu a ɛko tia, ɔhyew ne ngo a ɛko tia, ne compression set a ɛba fam.
