1 Rubber raw thlan chhuah
Plate heat exchanger rubber gasket chu a rualin gas lam atanga temperature sang tak, tui lam atanga pressure sang tak chanvo, leh boruak nena inzawmna nei bawk, hnathawh dan tur a harsa zawk. Chuvangin, material chu heat compression resistance tha tak a ni tur a ni a, tui leh a steam medium pawh a tuar thei tur a ni. Chutiang dinhmunah chuan EPDM atanga 40% ~ 50 % propylene mass fraction thlang tur a ni, a chhan chu he EPDM elasticity chi hi a tha ber a ni.
Third monomer mass fraction sang tak nei EPDM hian elasticity tha tak leh compression set hniam tak a nei a; mahse, cross-linking sang tak avang hian break-a tensile strength leh elongation a hniam zawk a, aging resistance pawh a tha lo hle. Tin, ENB hi third monomer atana hman EPDM hian HD hmanga EPDM aiin aging resistance a tha zawk bawk.
2 Curing system a ni
A tlangpuiin EPDM rubber hi vulcanization system chi hnih hmangin vulcanized theih a ni a, chungte chu peroxide leh sulfur yellow vulcanization te an ni. Peroxide vulcanization system-a cross-linking bond structure chu CC bond a ni a, sulfur vulcanization system-a cross-linking bond structure chu CS bond a ni thung. CC bond hi CS bond aiin thermally stable zawk a nih avangin high temperature resistant EPDM rubber chu peroxide hmangin vulcanized a ni. Peroxide hman lar ber chu DCP a ni. DCP dosage a san chuan vulcanized rubber chu a tir lama undersulfurization, chakna hniam leh deformation lian tak aangin chakna tihpun leh deformation tlahniam lamah a inthlak zauh zauh a tichuan vulcanization degree chu a sang lehzual a, a chakna a tlahniam tan a, deformation chu a tlem berah a thleng a; a tawpah chuan vulcanizing agent a tam lutuk hnuah molecular chain thenkhat chuan chain degradation chu a titawp tan a, a chakna chu a tlahniam zel a, deformation chu a pung zauh zauh a ni.
3.Filler a ni
EPDM hi non-crystalline rubber a mi a ni a, raw rubber chakna a sang lo. Mahse reinforcing filler kan dah hnuah chuan a chakna chu nasa takin a pung a ni. Reinforcing filler hian a tlangpuiin heat resistance-ah nghawng a nei tlem hle a, mahse filler tam zawk hian rubber-a heat resistance a tichak tho a, mahse a senso pawh a ti tlem bawk.
Carbon black grade a san chuan compression set a tlahniam a, elasticity a sang a, a chakna a tlahniam bawk. N990 carbon black chakna hi a hniam lutuk a, siamchhuahnaah pawh thunun harsa tak a nih avangin hman a ni lo. N762 carbon black thlan hian compression set value hniam tak a hmu thei a ni. Carbon black dispersion awlsam zawk leh processing performance tha tak neih theih nan plasticizer paraffin oil tlemte thlang la, chu chu ethylene propylene rubber nen a inmil hle.
4. Crosslinking agent a ni
EPDM main chain-ah hian unsaturated bond a awm lo a, peroxide vulcanization hman theih ni mahse vulcanization speed erawh a slow a, crosslinking efficiency a hniam hle. Vulcanization process stabilize leh ti chak tur chuan crosslinking agent hman a ngai a ni. TAC/GR enkawl tawh hi dispersion leh weighing atan a tha zawk.
TAC/GR a pun zel chuan vulcanized rubber tensile strength, elongation at break leh compression permanent deformation te a tlahniam a, constant tensile stress MH value pawh a sang chho bawk. Vulcanized rubber crosslinking density a tha zawk a, mechanical property a tlahniam a, mahse elasticity a lian zawk tih hmuh theih a ni. Chutih rual chuan ML value a tlahniam a, hei hian Mooney viscosity a tlahniam tih a tilang a, rubber fluidity a ti sang a, process pawh a awlsam hle tih a tilang bawk ts1 chu a bul berah chuan a danglam lo va, t 90 value pawh a tawi a, vulcanization speed pawh a tha zawk tih a chiang hle. Aging performance chu TAC/GR 1.5phr-ah a chhe zawk a ni. Hei hi cross-linking aid awm vang a ni thei a, peroxide vulcanization process a tichak a, vulcanization hun a ti tawi a, temperature sang takah rubber molecular chain breakage leh disproportionation awm theihna a tihtlem bawk. A tam lutuk chuan rubber aging cross-linking a tichak a, EPDM heat resistance a ti tlem bawk. Kan khaikhin hnuah compression permanent deformation hi 2phr ah a tha zawk a, heat resistance pawh a sacrificed vak lo a, chuvangin TAC/GR hi 2phr ah hman a ni.
5.Antioxidant a ni
EPDM hi 150 ah hian rei tak hman theih a ni a °C , mahse 150 °C hnuah chuan molecule te chu an upa chho zauh zauh tan a, 180 °C ah chuan rubber molecular chain chu zawi zawiin a chhe vek ang. Temperature sang takah a hnathawh that zawk nan chuan protective additives hman a ngai a ni. Water-vapor media-ah chuan antioxidant RD hi hman theih a ni a, hei hian temperature sang takah a do thei a, mahse vulcanization erawh a nghawng awlsam lo. Tin, 0.5phr antioxidant D hmang hian boruakah oxygen a do theihna a tichak a, flexural fatigue resistance a tichak bawk. RD/anti-butyl ratio chu=1.8/0.5 a ni.
Tawpna
High-temperature water vapor-resistant high elasticity EPDM rubber siam chhuah a ni a, a ngaih pawimawh ber chu aging resistance tihpun leh compression permanent deformation value tihtlem tumna hnuaia mechanical property te zawm a ni.
( 1) EPDM rubber raw chu propylene 40%~50% leh ENB medium mass fraction hmangin monomer pathumna atan thlan a ni.
( 2) Vulcanization system hian DCP/ TAC a hmang a, hei hian crosslinking efficiency, aging resistance leh process performance tihchangtlunna kawngah a pui a ni.
( 3) High elasticity carbon black N762 a theih ang anga hmang la, hei hian media permeability leh aging performance laka invenna a tichak thei a, a man pawh a tihtlem thei bawk.
( 4) Antioxidant RD/antioxidant D venhimna system hmang la, high-temperature antioxidant RD chu a bulpui ber a ni a, flexural fatigue-resistant leh ozone-resistant antioxidant D chu auxiliary atan hman a ni.
( 5) Production process hian vulcanization degree tihsan nan high-temperature secondary vulcanization a hmang a.
(6) Tui lum lutuk leh tui vapor-a EPDM hnathawh dan hi boruak (temperature inang) aiin a tha zawk tih a chiang. Mahse chuti chung pawh chuan hun rei tak chhunga a temperature hman dan chu 150 aia tam a la ni lo °C ; impact temperature 165 °C a ni a, a sang ber chu 180 °C aia tam a ni thei lo.
