Diad industriya na panaggawa na produkto, saray inhenyero ya responsable ed panag-seal et kaslakan ya sanka-demand ya membro na sakey a project team.
No say makina et normal ya mankikimey, anggapoy mannononot ed sika; balet no say kagawaan et nawalaan na saray leak (na danum, langis, odino gas) diad pasen na kustomer, say unonan toon manresponsabli et andi-duaruwan say sealing engineer.
Say structural engineer et unaan ton usisaen so sukat na kanal, tan kumpirmaan ton susto so inkadrowing da unong ed saray detalye na tolerance. Say departamento na IQC et man-verify ed report na pabrika, ya man-verify no saray produkto ya isusuplay na saray manunan manggagawa et makakasumpal ed amin ya estandarte. Diad kaunoran, say responsabilidad ed panagsukimat ed inkagba et walad mismon inhenyero na panagselyo.
Inekal mo so depektibon O-ring; say tapew to et ag-aderal, anggapoy bitak odino tanda na kemikal ya inkabulok. Say anguman labat et say inkapatat to tan ag la napawil ed datin itsura to.
Diad sayan yugtan, say pangiteen labat na imano ed tensile strength tan Shore hardness values ya akalista ed saray detalye na materyales na supplier et nayarin agmakaamta ed aktual ya sengegan na inkagba.
Diad lawak na saray sealed polymer materials, say long-term sealing performance et mabetbet ya nadetermina aliwan diad inka-malet na materyal odino say tensile strength to, noagta diad sakey a parameter ya mabetbet ya ag-ipapasen: say compression set (CS).
Aralen tayo iyan parametro ed taloran panmoria.
0 1
Panseal – antoy eksakton seal?
Antis ya pantongtongan so compressive permanent deformation, kaukolan ya ipetek so kaslakan ya lingon pakatalos ed mekanikal: say panag-seal et ag-akadepende ed "panangibara" noagta diad "pansuporta."
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No isuksok moy silicone O-ring ed metal ya kanal tan i-tight mo so flange, say silicone et na-compress (kaslakan et diad ratio ya 15%-30%).
Say silicone et sakey a materyal ya nababanat a maong. No na-compress, saray molecular chain to et mapilit ya na-distort, ya mamawala na mabiskeg ya rebound force (contact stress) ya labay ton ompawil ed orihinal ya kipapasen to.
Sayan rebound force et malet ya onsusumpa ed metal ya padir; diad teorya, basta onlampas ed presyon na pluido ed loob, ag lan balot onleak so medium.
Kanian, say kabaliksan na panag-seal et walad tuloytuloy ya pangiter na elastic force na saray silicone molecular chains ya walad silong na compression, ya mamasarag ed sikara ya malet ya onpeket ed saray metal ya tapew.
0 2
Antoy sengegan na pakaandi na selyo?
Lapud say panag-seal et mandedependi ed puersa ya mangipawil, antoy nagawa no naandi iyan puersa?
Anto so compressive permanent deformation?
Pinapatag mi so silicone gel na 25%, inluto mi ed oven ya 120℃ed loob na 70 oras, insan mi inekal tan inabuloyan min onlemew tan ompawil ed orihinal ya kurti to.
No sarag ton ipawil so orihinal ya kapal to, CS=0% (sakey a perpekton elastomer ya anggapo ed tua).
No sigpot ya onpatatdang tan ag la onabig, CS=100% (ya mangipapanengneng ya nagmaliw lan malet ya plastik).
Akin et ag makapawil ed orihinal ya kipapasen da iray kadena na molekula? Say isyu et walad mikroskopikon lebel:
Pisikal ya Lebel – Panrelaks ed Stress tan Panangipawil na Chain Segmentation
Say silicone et naporma lapud pankakasakey na andukey iran kadena na molekula. No ipaarap ed andukey a panag-compress ed atagey a temperatura,
Nababawasan toy internal stress to diad panamegley na kalkalnan panag-slide tan panag-organisa lamet.
Singa itan pangipeket ed sakey a malambot a bola na sinulid leksab na kahon ed loob na sakey taon-diad panaon ya ekalen mo itan, akaadapta la itan ed apatatdang a kurti to tan ngalngali la makapawil ed datin inkamalambok to.
Sayan pisikal ya "kompromiso" et manresulta ed kalkalnan ibabawas na puersa na rebound.
Chemical level – Pankabuyak tan pan-reorganisa na saray cross-linking bonds
Saya so sankaimportantian ya aspekto. Say inka-elastiko na silicone et mandedependi ed saray cross-linking bonds ed baetan na saray molecular chain (singa say sulfur-sulfur bonds).
Diad silong na atagey a temperatura tan andukey a panag-ipit, say orihinal a cross-linking bonds et nabuyak, kanian naandi so elastic traction force.
Say mas kritikal, saray free radicals ya nanlapud fracture et manporma lamet na balon cross-linked bonds diad silong na compressed conditions na materyal- ya epektibon mangi-lock ed saray molecular chains ed "flat state." Anggano naekal lay puersa ed paway, sarayan balon kemikal ya bedber et mangaamper ed materyal ya ompawil ed orihinal ya itsura to.
Physical slip + chemical recombination=compressive permanent deformation.
Say mas atagey ya CS value et manresulta ed mas patatdang ya silicone gel tan mas makapuy ya contact stress. Diad kaunoran, no say rebound force et magmaliw ya kulang no ikompara ed fluid pressure, onlelesa.
0 3
Panon yan nepeg ya asikasoen manlapud punto de bista na inhinyero?
Natan ta atalosan tayo la ray manunan mekanismo, panon tayon napaliisan iyan peligro no mandedesinyo tayo na saray seal tan manpipili na materyales?
1. No mangipapatalos na CS data, lanang ya ipalinew iray kondisyon na testing.
Say physical property table ya inter na supplier et mabetbet ya mangibabagan "permanent deformation under compression: 25%."Balet, diad anton temperatura, diad anton compression ratio, tan panon kabayag ya ginawa irayan sukat?
No say CS value et nasukat ed 25% ed 100 degree, nayarin ontagey itan ed masulok ya 50% diad aktual ya kondisyon na operasyon ya 150℃lapud maples ya thermal tan oxidative aging.
Say manunan kakaukolanen et no uusaren so balor na CS, say temperatura na test et nepeg ya ag-onkulang ed sankatageyan ya temperatura na produkto, tan say karukey na test et nepeg ya ag-onkulang ed 70 oras odino 168 oras. Saraman labat ya datos so nayarin manserbin balidon reperensya parad panagpili.
2. Manpokus ed cross-linking system imbes ya bulag ya pabalegen so hardness
No say CS value et ag makaabot ed saray kakaukolanen, agmo salien ya bawien so inka-malet na silicone gel-say inka-malet et ag makabawi ed permanentin deformation. Imbes, say interbensyon et nepeg ya ipaarap ed chemical cross-linking system na materyal.
No alaen so NBR o EPDM bilang alimbawa: saray tradisyonal a sistema na sulfur vulcanization et manporma na sulfur-sulfur bonds ya abeba so bond energy to, ya mainomay ya nabuyak tan nareforma ed atagey ya temperatura, kanian makapuy so CS values.
Diad pangagamil na sistema na peroxide vulcanization, naporma so carbon-carbon single bonds, ya walaan na atagey ya enerhiya na bond tan ag-ira nabuyak tan narekombinasyon ed atagey a temperatura na compression, kanian nabawasan so permanentin compression deformation.
Say trade-off et say ibawas na tear resistance na peroxide-vulcanized materials. Saya so mangirerepresenta na kaslakan a balanse ed baetan na pakagamor na "non-tearability" tan pamasiansia ed "rebound properties".
3. Panbayar ed materyal ya CS attenuation panamegley na structural design
No say CS value na materyal et na-optimize ed pisikal ya limitasyon to (alimbawa, 30%), panon tayon naseguro so tuloytuloy ya performance na sealing ed andukey a panaon ya pangusar?
Lapud amta tayon naandi so inkapekder to, nepeg tayon ilaktip iyan pakaandi ed compression allowance no mandedesinyo na sukat na groove.
Balet, say compression ratio et agnayarin pabalegen ya andi-anggaan. No say compression rate et alablabas ya atagey (onlampas ed 40%), say internal stress ed loob na polymer et ondarakel a maong, ya pansengegan na masakbay a pakabuyak na saray kadena na molekula tan lapud satan et mamapeles so pakaderal na CS.
Say sankaepektiboan ya paraan et parad saray structural engineer tan materials engineers ya mankakasakey ya makagawa na groove tolerance base ed stress relaxation curve-ya ag makaderal ed integridad na silicone odino ag makapansiansia na magenap ya sealing pressure ratio kayari na samploran taon.
Say panggawa na seal et mankabaliksan na pagmaliw ya kaaro tan kalaban na panaon.
Say tuan sealing engineer et aglabat manpopokus ed pangiseguro na watertight seal legan ya nasumpal so panag-assemble.
Say kapagaan da et no kasin, kayari na talora, lima, odino anggan samploran taon-diad silong na paulit-ulit ya pakawalaan na atagey a temperatura tan mabiskeg a presyon-say molecular chain et mansiansian malet ya akapeket ed tapew na metal.
No walay seal yo ya paulit-ulit ya onlelereg balet agyo nabidbir so sengegan, odino nalilingo so property tables na supplier-agkayo mapaga ya mitongtong ed sale engineer mi nipaakar ed saray drowing tan ag-asumpal ya sample.