Insait long wok bilong wokim ol samting, ol enjinia we i gat wok long pasim ol samting em ol i save mekim planti wok insait long wanpela projek tim.
Taim masin i wok gut, nogat wanpela man i tingim yu; tasol taim ol ikwipmen i kamapim ol lik (bilong wara, oil, o ges) long sait bilong kastoma, namba wan man i mas kisim asua em i no gat tupela tingting olsem em i 'sealing engineer'.
Pastaim 'structural engineer' i save glasim ol 'trench dimensions', na painimaut olsem ol i bin droim stret bihainim ol 'tolerance specifications'. IQC dipatmen i save sekim ripot bilong faktori, na sekim olsem ol prodak we ol bikpela kampani i save saplaim i inapim olgeta standet we ol i laikim. Long pinis bilong en, wok bilong skelim ol hevi i pundaun stret long han bilong 'sealing engineer'.
Yu rausim O-ring we i no wok gut; pes bilong en i stap gut, i no gat ol liklik bruk o mak bilong kemikel korosen. Wanpela senis tasol em olsem ol i bin flatim na ol i no inap long putim bek long seip bilong en.
Long dispela step, lukluk tasol long strong bilong 'tensile' na 'Shore hardness' we i stap insait long ol 'material specifications' bilong saplaia i no inap long painimaut as tru bilong feil.
Long sait bilong ol 'sealed polymer materials', longpela taim 'sealing' pefomens i no save kamap long strong bilong ol samting o strong bilong en, tasol long wanpela samting we planti taim ol i no tingim tumas: 'compression set' (CS).
Yumi ken lukluk gut long dispela paramita long tripela sait.
0 1
Siling – wanem samting tru ol i wok long silim?
Pastaim long toktok long 'compressive permanent deformation', em i bikpela samting long stretim wanpela tingting kranki bilong ol masin: 'sealing' i no dipen long "blok" tasol long "sapoting."
piksa
Taim yu putim wanpela silikon O-ring insait long ain grov na taitim 'flange', silikon i save pas (planti taim long wanpela 'ratio' bilong 15%-30%).
Silikon em i wanpela samting we i gat strongpela 'elastic'. Taim ol i presim, ol 'molecular chain' bilong en i save paul hariap, na dispela i save kamapim strongpela 'rebound force' (kontek stres) we i laik go bek long as bilong en.
Dispela 'rebound force' i sakim strong 'metal wall'; long tingting, sapos em i winim presa bilong wara insait long en, dispela samting bai no inap lik liklik.
Olsem na, as bilong 'sealing' i stap long wok bilong givim 'elastic force' long ol 'silicone molecular chains' aninit long presa, na dispela i mekim na ol i ken pas strong long ol metal pes.
0 2
Wanem samting i save mekim na sil i no wok gut?
Long wanem, 'sealing' i dipen long 'restoring force', wanem samting bai kamap sapos dispela 'force' i lus?
Wanem em 'compressive permanent deformation'?
Mipela i flatim silikon gel long 25%, kukim long aven long 120 digri inap 70 aua, bihain rausim na larim em i kol na i go bek long as bilong en.
Sapos em inap long stretim gut 'thickness' bilong en, CS=0% (wanpela gutpela 'elastomer' we i no stap tru).
Sapos em i flat olgeta na i no kamap orait gen, CS=100% (i soim olsem em i kamap strongpela plastik).
Bilong wanem ol 'molecular chain' i no inap long "go bek long as bilong en"? Hevi i stap long 'microscopic level':
Level bilong bodi – Stress Rilaksesen na Chain Segmentesen Rioganaisesen
Silikon i kamap taim ol longpela sen bilong ol molekiul i pas wantaim. Taim ol i putim presa longpela taim long bikpela hat,
Em i save daunim hevi insait long bodi bilong em long rot bilong 'sliding' na 'reorganization' isi isi.
Em i olsem yu presim wanpela 'fluffy ball' bilong 'yarn' long as bilong wanpela bokis inap wanpela yia-taim yu rausim, em i lain pinis long 'flatten' seip bilong en na i no inap long kisim bek 'fluffness' bilong en bipo.
Dispela "kompromis" bilong bodi i save mekim na strong bilong 'rebound' i go daun isi isi.
Kemikel level – Brukim na stretim gen ol 'cross-linking bonds'
Dispela em i bikpela samting tru. Elastisiti bilong silikon i dipen long ol kros-linking bon namel long ol molekiul sen (olsem salfa-salfa bon).
Aninit long bikpela hat na longpela taim bilong presim, ol 'cross-linking bond' i save bruk, na dispela i save mekim 'elastic traction force' i lus.
Moa bikpela samting, ol fri radikal we i kamap long bruk bai kamapim gen ol nupela 'cross-linked bon aninit long ol 'compressed conditions' bilong samting -na bai pasim ol 'molecular chains' long wanpela "flet stet." Maski ol i rausim strong bilong ausait, ol dispela nupela kemikel bon i pasim ol samting long go bek long ples bilong en.
Slip bilong bodi + kemikel rekombinesen=kompresen permanen difomesen.
Sapos CS veliu i go antap dispela i save mekim silikon gel i kamap flat na kontek stres i no strong tumas. Bihain, taim strong bilong 'rebound' i no inap long presa bilong wara, 'leakage' i save kamap.
0 3
Olsem wanem dispela i mas kamap long sait bilong enjiniaring?
Nau yumi kliagut long ol samting i save kamap, olsem wanem yumi ken abrusim dispela hevi taim yumi wokim ol 'seal' na makim ol samting bilong wokim?
1. Taim yu tanim CS data, oltaim kliarim ol tes kondisen.
Tebol bilong ol samting bilong bodi we saplaia i givim i save tok olsem "permanent deformation aninit long kompresen: 25%."Tasol, long wanem kain tempereja, aninit long wanem kain 'compression ratio', na hamas taim ol i bin mekim ol dispela skelim?
Sapos ol i skelim CS veliu long 25% long 100 digri, em i ken go antap long 50% aninit long ol wok kondisen bilong 150 digri bikos long hariap bilong 'thermal' na 'oxidative aging'.
Bikpela samting ol i mas mekim em olsem taim ol i skelim CS veliu, tes tempereja i no ken i stap daunbilo long mak bilong prodak, na taim bilong tes i mas stap inap 70 aua o 168 aua. Ol dispela kain data tasol inap long stap olsem gutpela refrens bilong makim.
2. Lukluk long kros-linking sistem na noken skruim hat bilong en
Sapos CS veliu i no inapim ol samting yu laikim, noken traim long kompensetim long rot bilong skruim strong bilong silikon gel-strong i no inap senisim 'permanent deformation'. Nogat, ol i mas mekim wok long 'chemical cross-linking system' bilong dispela samting.
Kisim NBR o EPDM olsem eksampel: ol tradisenel salfa vulkenaisesen sistem i save kamapim ol salfa-salfa bon wantaim liklik bon eneji, we i save bruk na senis long bikpela tempereja, na dispela i save kamapim ol CS veliu we i no gutpela.
Long rot bilong adoptim wanpela 'peroxide vulcanization' sistem, ol i save kamapim ol 'carbon-carbon singel bon, we i save soim bikpela 'bond energy' na i no inap long bruk na bungim gen aninit long bikpela -temperature kompresen, na dispela i save daunim tru 'permanent compression deformation'.
Trade-off em i go daun long 'tear resistance' bilong ol 'peroxide-vulcanized materials. Dispela i makim wanpela gutpela balens namel long winim "non-tearability" na holim "rebound properties".
3. Kompensesen bilong 'material CS atenuation' long rot bilong 'structural design'
Sapos CS veliu bilong dispela samting i bin kamap gutpela long mak bilong en (olsem, 30%), hau bai yumi ken mekim gutpela wok bilong pasim samting longpela taim?
Long wanem mipela i save olsem em bai lusim sampela strong bilong en, mipela i mas putim dispela lus insait long 'compression allowance' taim mipela i wokim ol 'groove dimensions'.
Tasol, ol i no inap long skruim 'compression ratio' oltaim oltaim. Taim 'compression rate' i antap tumas (winim 40%), 'internal stress' insait long 'polymer' i go antap tru, na dispela i save mekim ol 'molecular chains' i bruk hariap na dispela i save mekim CS i bagarap hariap.
Gutpela rot tru em long ol 'structural engineers' na ol 'materials engineers' i mas wok bung wantaim long kamapim wanpela 'groove tolerance' we i kamap long 'stress relaxation curve-wanpela we i no inap bagarapim 'silicone integrity' o i no inap long holim inap 'sealing pressure ratio' bihain long 10-pela yia.
Wokim wanpela sil i min olsem yu mas kamap pren na birua bilong taim.
Wanpela trupela 'sealing engineer' i no save lukluk tasol long mekim 'sealing' i no inap long go insait long en taim ol i pinisim wok bilong bungim ol samting.
Wari bilong ol i stap long sapos, bihain long tripela, faivpela, o tenpela yia-aninit long ol i stap planti taim long bikpela hat na bikpela presa-molekiul sen bai stap strong yet long metal pes.
Sapos yu gat wanpela sil we i save lik planti taim tasol yu no inap long painimaut as bilong en, o yu painim ol tebol bilong ol samting bilong saplaia i paul-yu ken toktok wantaim 'sale engineer' bilong mipela wantaim ol droing na ol feil sempel bilong yu.