We a PTFE ay-tεmprachכ adhesive tep dεn de yuz am na hot envayroment – se, 200°C fכ wik כ mכnt – di silikon prεshכn-sεnsitiv adhesive (PSA) kin chenj. Pil trɛnk kin go ɔp, fɔdɔm, ɔ transfa rɛsɛdyu. di kכhεshכn kin inkrεs (brittleness) כ dכn (cohesive failure).
Nɔto ɔl di silikon PSA dɛn de biev di sem. di difrεns dεm de kam dכn to polimכr kכmכshכn (mεtil vs. mεtilfεnyl), kכroslink mεkanism (pεrכksayd vs. adishכn kכryu), εn di rεshכn fכ MQ rεsin to rכba.
Aokai PTFE de yuz bɔku silikon PSA gred dɛn na wi tep dɛn. Dis gayd de ɛksplen wetin kin apin to trɛnk ɛn kɔhyeshɔn afta di ay-tɛmpracha dɔn ol fɔ ɛni gred, ɛn aw fɔ pik di rayt wan fɔ yu aplikeshɔn.
Wetin De Apin to Silikɔn PSA Ɔnda Ɔt – Tu Fɛil Mɔd
we dεn ol na ay tεmprachכ (200-250°C), silikon PSA dεm kin gεt tu chenj dεm we de agens:
1. Pɔst-krɔs-link (de mek i brit) .
di fכnshכnal grup dεm we nכ riak de kכntinyu fכ riak, we de inkrεs di kכroslink dεnsiti. di trεnk we di fכs we yu kin pul kin go כp fכ sכm tεm, dεn kin fכl shap shap as di adhesive de kam tu rigid. I tan lɛk se statik shia trɛnk de go ɔp, bɔt di pawa we yu de ol ɛn di impak rɛsistɛns de pwɛl. Di adhesive film kin at ɛn krak.
2. di bakbon dεgradashכn (i de mek di peel lכs εn rεsidεnt) .
di polydimethylsiloxane bakbon de go tru sayklayzeshn εn chen scission. Pil trɛnk de drɔp ɔltɛm. di adhesive kin transfכm to di sabstεrayt (rεsidyu) כ fεil kכhεsiv wan. dis na kכmכn insay lכw grεd mεtil silikon PSA dεm.
Ki modulating paramita dɛn:
Fɛnil kɔntinyu (high = bɛtɛ ɔt rɛsistɛns) .
Krɔslink density ɛn di kayn we aw i de mɛn (adishɔn kɔrej vs. pɔroksayd mɛn) .
Ratio di MQ resin to silikon rɔba
Gret Klasifikeshɔn dɛn bay Kwɛmyuɛl Strukchɔ
1. Standart polidimetilsilɔksan (mɛtil-tayp silikon PSA) .
di rεtεnshכn fכ di pil afta i dɔn ol (200-250°C): di trεnk we di pil de go כp sכmtεm fכs, dεn de dכn. afta 7 dez na 250°C, di peel ritεnshכn na כnli 50-70% . Pɔfɔmɛnshɔn kin drɔp fast fast na ay tɛmpracha. digradashכn de kכmכt frכm sayklayshכn fכ di dimethyl siloxane bakbon.
kכhεshכn stεbiliti: di vεshכn dεm we dεn kכl pεrכksayd (εgz., KR-101) gεt rεsidyual initiator dεm we de mek dεn nכ kכntrol di post-kכryushכn – adhesive de harden εn embrittles. di fכs shia strכng de impruv, bכt di pawa we yu ol de dכp, εn di kכhεsiv fεil de apin כnda hεt. di vεshכn dεm we dεn kכl adishכn bεtε sכm bכt stil limited bay di pwεl inhεrent hεt rεsistεns fכ di dimεtil bakbכn.
2. Methylphenyl polysiloxane (grɛd we nɔ de ambɔg di ay tɛmpracha) .
di ritεnshכn fכ di pכl afta i dɔn ol: di fεnyl sayd chen dεm de disrupt di rεgulεr pak fכ di dimεtil sεgmεnt dεm εn de sכpres sayklayzeshכn dεgradashכn. afta 7 dez na 250°C, di peel strכng rεtεnshכn pas 85% . di hכy-fεnyl fכmyuleshכn dεm de mεnten stebul pil prכpati dεm ivin na 260-288°C.
Cohesion stebiliti: I fayn. Shia strכng de chenj sכmtεm; di holdin pawa ritεnshכn pas 80%. di adhesive layεr de stil fleksibul lכng tεm witout embrittlement כ rεsidεnt. Adishɔn-kyur ay-fɛnil gred dɛn na di prɛmiɔm tɛmli stebul silikon PSA.
3. Speshal ay-pil ɛn lɔw-pil kɔstɔm gred dɛn
High-peel gred (eg, Dow 7385, tipik peel >10N/25mm): High MQ resin loading de gi fayn fayn initial tak ɛn peel trɛnk, bɔt na di kɔst fɔ ɔt rɛsistɛns ɛn kɔhyeshɔn stebiliti. dεn de sho big peel dכp afta dεn ol εn dεn kin prona fכ rεsidεnt bikoz fכ rεsin tεmכl dεkכmכshכn. Yuz ɔl fɔ aplikeshɔn dɛn we nɔ gɛt bɛtɛ tɛmpracha we kin apin wan wan tɛm.
Low-peel, high-cohesion protective film gred: Ay kroslink density de gi stebul peel pefomans ɛn fayn fayn ej stebiliti, bɔt low initial tak. Afta dɛn dɔn ol, dɛn kin kɔntinyu fɔ gɛt wanwɔd bɔt dɛn kin at, we kin ridyus di kɔnfɔmabiliti to rɔf say dɛn.
Nɔto fɔ kɔntinyu fɔ gɛt ay ɔt; ɛkspɛkt rɛsɛdyu afta dɛn dɔn ol
Protektiv film, ay koheshon, low tak
High-kroslink lɔw-pil gred
Eksɛlɛnt ol stebiliti bɔt hardened ɛn less conformable
Aokai PTFE rεkomεndεshכn : Fכ eni PTFE tep we go si sustained tεmprachכ pas 200°C, spεsifa wan adishכn-kכry mεtilfεnyl silikon PSA. Di apfrɔnt kɔst bɛtɛ, bɔt i de mek fil nɔ pwɛl bikɔs ɔf di adhesive rɛsɛdyu ɔ di bond lɔs.
Sɔmari – Match Silikɔn PSA Gred to Tɛmral Dimand
Methyl-type silicone PSA (especially peroxide-cured) fayn fɔ yuz am wan wan tɛm ɔ we nɔ gɛt bɛtɛ tɛmpracha. afta 7 dez na 250°C, epk 30-50% peel lכs εn posεbul embrittlement.
methylphenyl (high-phenyl) silicone PSA de kip >85% peel strכng εn fleksibul kכhεshכn afta di sem ol. Na di choice fɔ kɔntinyu 200-250°C savis.
di kכroslink mεkanism impɔtant bכku: adishכn kכryu (haydrosilylation) de fa mכr stebul pas pεrכksayd kכryu.
High-peel gred dεm de tred כf aging stebiliti fכ initial tak – avכyd dεm in hot aplikεshכn.
Fכ dimand ay-tεmprachכ bכnd, Aokai PTFE de yuz adishכn-kכyr mεtilfεnyl silikon PSA dεm. Wi kin gi di peel ritɛnshɔn data afta 1000h na 250°C we yu aks fɔ am.
