Engtikah nge a PTFE high-temperature adhesive tape hi boruak lum takah hman a ni a – sawi ta ila, 200°C-ah kar emaw thla tam emaw chhung – silicone pressure-sensitive adhesive (PSA) hi a danglam thei a ni. Peel chakna chu a sang thei a, a tlahniam thei a, residue a transfer thei bawk. Cohesion hi a pung (brittleness) emaw a tlahniam (cohesive failure) emaw a ni thei.
Silicone PSA zawng zawng hi an awm dan a inang vek lo. A danglamna chu polymer composition (methyl vs. methylphenyl), crosslinking mechanism (peroxide vs. addition cure), leh MQ resin leh rubber ratio-ah a tla thla a ni.
Aokai PTFE hian kan tape-ah hian silicone PSA grade hrang hrang a hmang a. He guide hian grade tin tan high-temperature aging hnua peel strength leh cohesion a awm dan te, i application atana a dik tak thlan dan tur a sawifiah bawk.
Temperature sang (200-250°C)-a kum upa a nih chuan silicone PSA-te hian inthlak danglamna pahnih an nei thei a:
1. Post-crosslinking (brittleness a thlen) .
Unreacted functional groups te chuan an react chhunzawm zel a, crosslink density a tisang a ni. Initial peel strength chu rei lo te chhung atan a sang thei a, chutah chuan adhesive a rigid lutuk avangin nasa takin a tla thei bawk. Static shear strength a sang chho niin a lang a, mahse holding power leh impact resistance a tlahniam thung. Adhesive film chu a khauh a, a chhe bawk.
2. Backbone degradation (peel hloh leh residue a thlen) .
Polydimethylsiloxane backbone hi cyclization leh chain scission hmanga tih a ni. Peel chakna a tlahniam zel. Adhesive chu substrate (residue) ah a transfer thei a, a inzawm khawm thei bawk. Hei hi low-grade methyl silicone PSA-ah chuan a awm fo thin.
Modulating parameter pawimawh tak takte chu:
Phenyl awm zat (a tam zawk = lumna do theihna tha zawk) .
Crosslink density leh curing chi hrang hrang (addition cure vs. peroxide cure) a ni.
MQ resin leh silicone rubber inkar ratio
Chemical Structure hrang hranga Grade thliar hrang hrang
1. Standard polydimethylsiloxane (methyl chi hrang hrang silicone PSA) hmanga siam a ni.
Kum upa lam hnua peel retention (200-250°C): Peel chakna hi a tir lamah a sang deuh a, chutah chuan a tlahniam leh thin. 250°C-a ni 7 hnuah chuan peel retention chu 50-70% chauh a ni . Temperature sang zawkah chuan performance a tlahniam rang zawk. Degradation hi dimethyl siloxane backbone cyclization atanga lo chhuak a ni.
Cohesion stability: Peroxide-cured version (eg, KR-101) te hian residual initiators an nei a, chu chuan post-curing control loh a thlen thin – adhesive hardens leh embrittles. Initial shear strength a tha a, mahse holding power a tlahniam a, heat hnuaiah cohesive failure a awm bawk. Addition-cured version te hi tlem a tha zawk mahse dimethyl backbone inherent heat resistance tha lo vangin a la limited tho.
2. Methylphenyl polysiloxane (a lumna sang takah a do thei grade) .
Kum upa lam hnua peel retention: Phenyl side chain hian dimethyl segments regular packing a tibuai a, cyclization degradation a titawp bawk. 250°C-a ni 7 hnuah chuan peel strength retention chu 85% aia tam a ni . High-phenyl formulations hian 260-288°C-ah pawh peel property nghet tak a vawng reng a ni.
Cohesion stability: A tha hle. Shear chakna hi a danglam tlem hle a; holding power retention chu 80% aia tam a ni. Adhesive layer hi hun rei tak chhung chu a flexible reng a, embrittlement emaw residue emaw awm lovin. Addition-cured high-phenyl grades te hi premium thermally stable silicone PSA a ni.
3. High-peel leh low-peel custom grade bik
High-peel grades (eg, Dow 7385, typical peel >10N/25mm): MQ sang resin loading hian initial tack leh peel strength tha tak a pe a, mahse heat resistance leh cohesion stability man a to thung. Kum upa lam hnuah peel drop lian zawk an lantir a, resin thermal decomposition vangin residue an nei duh hle. Temperature hniam lama hmanna hun remchang atan chauh hman tur.
Low-peel, high-cohesion protective film grades: Crosslink density sang tak hian peel performance nghet tak leh aging stability tha tak a pe a, mahse initial tack hniam tak a pe thung. Kum upa lam hnuah pawh an inzawm tlat a, mahse an khauh ta a, chu chuan rough surface-a conformability a tihtlem phah a ni.
Crosslinking Mechanism – Peroxide leh Addition Cure (Methyl Base inang) te hi a inang lo hle.
Methyl polymer ang chiah hmang pawh hian curing method hian tar chakna chu nasa takin a tidanglam thin.
1. Peroxide hmanga tihdam (conventional early generation) .
Residual peroxide hian high-temperature aging laiin control loh post-crosslinking a tichhuak thin.
Peel strength chu a tir lamah a spike a, chutah chuan a collapse nasa hle.
Cohesion hi rei lo te chhungin a sang chho a, chu chu embrittlement leh holding power failure a awm leh thin.
>85% peel retention, embrittlement awm lo, >80% holding power retention a awm bawk
Hun rei lote chhunga lumna sang tak, a man a to
Standard methyl-type, addition-cured, post-bake-a tihdam (eg, 7657) tih a ni.
Acceptable mahse peel degradation engemaw zat leh cycle rei tak chhunga embrittlement awm thei beisei ang che
Initial peel sang tak a ngai a, temperature hniam tak chauh a ni
A peel sang tak methyl grade a ni
Khua lum chhunzawm zel tur atan ni lovin; tar hnuah residu beisei
Protective film, cohesion sang, tack hniam
Crosslink sang tak nei low-peel grade a ni
Aging stability tha tak mahse hardened leh conformable lo zawk
Aokai PTFE rawtna : PTFE tape eng pawh 200°C aia sang sustained temperature hmu tur tan chuan addition-cured methylphenyl silicone PSA tarlan tur a ni. Upfront cost a sang zawk a, mahse adhesive residue emaw bond loss emaw avanga field failure a veng thei.
Methyl-type silicone PSA (a bik takin peroxide-cured) hi a hun lai emaw, temperature hniam emawa hman atan chauh a tha. 250°C-a ni 7 awm hnuah 30-50% peel loss leh embrittlement awm thei beisei ang che.
Methylphenyl (high-phenyl) silicone PSA hian kum upa lam ang chiah hnuah >85% peel strength leh flexible cohesion a vawng reng a ni. 200-250°C service chhunzawm zel tur chuan duhthlan tur a ni.
Crosslinking mechanism hi a pawimawh hle: addition cure (hydrosilylation) hi peroxide cure aiin a stable zawk daih.
High-peel grades hian aging stability chu initial tack atan an trade off a – hot application-ah chuan pumpelh rawh.
High-temperature bonding mamawhna atan Aokai PTFE hian addition-cured methylphenyl silicone PSAs a hmang a. Dilna angin 250°C ah 1000h hnuah peel retention data kan pe thei bawk.
