Manufacturing industry-ah chuan sealing lama mawhphurtu engineer-te hi project team-a member mamawh ber an ni tlangpui.
Machine chu a hnathawh dan pangngaia a thawh lai chuan tumahin an ngaihtuah ngai lo che; mahse, hmanrua chuan customer awmna hmunah leak (tui, oil, gas) a siam hnu chuan, thubuai siamsak hmasak ber chu sealing engineer a ni tih rinhlelh rual a ni lo.
Structural engineer chuan trench dimension te chu a enfiah hmasa a, tolerance specification angin dik taka ziah a nih thu a nemnghet a ni. Chumi hnuah IQC department chuan factory report chu a finfiah a, thil siamtu lian ber berte supply-te chuan standard mamawh zawng zawng a tlin leh tlin loh a finfiah a ni. A tawpah chuan failure analysis mawhphurhna chu sealing engineer chungah a tla vek a ni.
O-ring chhia chu i paih chhuak a; a chunglam chu a la awm reng a, a chhe lai emaw, chemical corrosion chhinchhiahna emaw a awm lo. A tihdanglamna awm chhun chu a flattened tawh avangin a pianphung hmasa angin a awm leh thei tawh lo.
Hetiang dinhmunah hian supplier-in material specification-a a tarlan tensile strength leh Shore hardness value chauh ngaihtuah hian a chhiat chhan tak tak chu a hriat theih loh phah thei a ni.
Sealed polymer materials khawvelah chuan hun rei tak-sealing performance hi material hardness emaw tensile strength emaw atanga teh ni lovin, parameter ngaihthah fo thin: compression set (CS) atanga teh a ni fo thin.
He parameter hi thlirna pathum atang hian thuk takin han chhui ila.
0 1
Sealing – eng chiah nge seal a nih?
Compressive permanent deformation chungchang kan sawi hmain mechanical misconception tlanglawn tak pakhat siamthat a pawimawh hle: sealing hi "blocking" ah ni lovin "supporting" ah a innghat zawk a ni.
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Metal groove-a silicone O-ring i dah a, flange i khauh chuan silicone chu a compress (a tlangpuiin 15%–30% ratio-ah) a ni.
Silicone hi thil elastic tak a ni. Compress a nih chuan a molecular chain te chu tharum hmanga tihdanglam a ni a, chu chuan rebound force (contact stress) chak tak a siam a, chu chuan a dinhmun hmasa lama kir leh a tum a ni.
He rebound force hian metal wall chu nghet takin a dodal a; theoretically chuan internal fluid pressure a pelh chhung chuan medium chu a leak lovang.
Chuvangin, sealing thupui ber chu compression hnuaia silicone molecular chain-te’n elastic force an pek chhunzawm zelnaah a awm a, chu chuan metal surface-ah nghet takin a innghat thei a ni.
0 2
Eng thilin nge seal a chhiat chhan?
Sealing hi restoring force-ah a innghat a nih avangin he force hi a bo chuan eng nge thleng ang?
Compressive permanent deformation chu eng nge ni?
Silicone gel chu 25% in kan flatten a, oven-ah 120 degree-ah darkar 70 chhung kan bake a, chutah chuan kan la chhuak a, a lum a, a pianphung pangngaiah kan dah leh ta a ni.
A thickness hmasa ber chu a rawn siam let leh thei a nih chuan CS=0% (a tak takah chuan awm lo elastomer famkim) a ni.
A flatten vek a, a lo harh chhuak lo tak tak a nih chuan CS=100% (rigid plastic a lo ni tawh tih a tilang).
Engvangin nge molecular chain te hi "a bul tanna hmunah an kir leh" theih loh? Thubuai chu microscopic level-ah a awm a ni:
Taksa Level – Stress Relaxation leh Chain Segmentation Reorganization
Silicone hi molecular chain sei tak tak inzawmkhawm atanga siam a ni. Temperature sang takah rei tak compression an neih chuan, .
Zawi zawiin a sliding leh reorganization hmangin a chhungril lama harsatna a tihziaawm thin.
Box hnuai lama yarn ball fluffy tak chu kum khat chhung press ang mai a ni-i chhuah meuh chuan a flattened shape-ah a insiamrem tawh a, a original fluffiness chu a la let leh thei tawh lo.
He taksa "compromise" hian rebound force a tlahniam zauh zauh a ni.
Chemical level – Cross-linking bonds tihchhiat leh insiam thar lehna
Hei hi a pawimawh ber a ni. Silicone elasticity hi molecular chain (sulphur-sulphur bonds ang chi) inkara cross-linking bonds-ah a innghat a ni.
Temperature sang leh compression rei tak hnuaiah chuan original cross-linking bonds te chu a chhe a, chu chuan elastic traction force a hloh phah a ni.
A pawimawh zawk chu, fracture atanga free radicals lo chhuak te hian material compressed condition hnuaiah cross-linked bonds thar a siam leh ang-molecular chain te chu "flat state" ah effective takin a lock ang. Pawn lam chakna chu lak chhuah a nih hnuah pawh heng chemical bonds tharte hian thil chu a awm dan pangngaiah a kir leh thei lo.
Taksa slip + chemical recombination=hmanga compressive permanent deformation a ni.
CS value sang zawk chuan silicone gel a flatter a, contact stress a chak lo zawk bawk. A tawpah chuan fluid pressure nena khaikhin chuan rebound force a tling tawk lo a nih chuan leakage a awm thin.
0 3
Engineering lam atanga engtin nge hei hi hmachhawn tur?
Tunah chuan a hnuaia mechanism kan hriatthiam tawh avangin engtin nge seal design leh material thlan hunah he risk hi kan pumpelh theih ang?
1. CS data hrilhfiah dawnin testing condition te chu chiang takin sawi thin ang che.
Supplier-in physical property table a pekah chuan "compression hnuaia permanent deformation: 25%" tih a awm fo.Mahse, eng temperature-ah nge, eng compression ratio hnuaiah nge, eng chen nge heng tehnate hi an lak?
CS value hi 100 degree-a 25%-a teh a nih chuan, accelerated thermal leh oxidative aging vangin actual operating conditions 150 degree-ah 50% aia sangah a surge thei a ni.
Thil tul ber chu CS value endik hunah test temperature chu product hnathawhna temperature sang ber aia hniam lo tur a ni a, test hun chhung chu darkar 70 emaw darkar 168 emaw tal a ni tur a ni. Chutiang data chauh chu thlan chhuahna atana reference dik tak a ni thei.
2. Mitdel anga hardness tihpun ai chuan cross-linking system lam ngaihtuah zawk rawh
CS value hian a mamawh a tlin loh chuan silicone gel hardness tihpun hmangin compensate tum suh-hardness hian permanent deformation a tidanglam thei lo. Chu ai chuan intervention chu material-a chemical cross-linking system lam hawi tur a ni.
NBR emaw EPDM emaw entirnan la ila: traditional sulfur vulcanization system te hian bond energy hniam tak nei sulfur-sulphur bonds an siam a, chu chu temperature sang takah chuan a chhe thei a, a siam tha leh thei a, chu chuan CS value a tichhe thei a ni.
Peroxide vulcanization system hman a nih chuan carbon-carbon single bonds siam a ni a, chu chuan bond energy sang tak a lantir a, high-temperature compression hnuaiah cleavage leh recombination a do thei a, chu chuan permanent compression deformation nasa takin a tihtlem phah a ni.
Trade-off chu peroxide-vulcanized materials tear resistance tlahniam a ni. Hei hian "non-tearability" neih leh "rebound properties" vawn reng inkara balance tlangpui a entir a ni.
3. Structural design hmanga material CS attenuation pek chhuah
Material CS value chu a physical limit (eg, 30%) thlenga optimized a nih chuan, engtin nge hun rei tak- hman chhunga sealing performance chhunzawm zel kan tih theih ang?
Resilience engemaw zat a hloh dawn tih kan hriat avangin groove dimension design-naah he hloh hi compression allowance-ah kan dah tel tur a ni.
Mahse, compression ratio hi hun tiam nei lovin tihpun theih a ni lo. Compression rate a san lutuk (40% aia tam) a nih chuan polymer chhunga internal stress chu exponential-in a pung a, chu chuan molecular chain-te mechanical fracture a thlen hma a, chu chuan CS a tichhe chak zawk a ni.
A tha ber chu structural engineer leh materials engineer te tan chuan stress relaxation curve-a innghat groove tolerance chu kum sawm hnuah silicone integrity tichhe lo emaw, sealing pressure ratio tling tak vawng reng thei lo emaw hmanga groove tolerance siam chhuah hi a ni.
Seal siam tih awmzia chu a bul berah chuan hun ṭhian leh hmêlma nihna a ni.
Sealing engineer dik tak chuan assembly zawh hunah tui tlak lohna seal neih theihna tur chauh a ngaihtuah lo.
An ngaihtuahna chu kum thum, kum nga, kum sawm pawh ni se-te chu temperature sang leh pressure nasa tak hnuaia an inhriat nawn leh hnuah-molecular chain chu metal surface-ah nghet takin a la inzawm reng dawn em tih hi a ni.
Seal i neih chuan a leak nawn fo thin a, mahse a chhan i hre thei lo a nih chuan, emaw, supplier-te property table-te chu a buaithlak i tih chuan-i drawing leh sample failed te nen kan sale engineer hnenah zalen takin biak theih a ni.