Silicone PSA Bayan Tsufa Maɗaukakin Zazzabi: Ƙarfin Kwasfa da Haɗin Kai ta Girma

Lokacin a Ana amfani da tef ɗin PTFE mai zafi mai zafi a cikin yanayi mai zafi - ka ce, 200 ° C na makonni ko watanni - mannen matsi na silicone (PSA) na iya canzawa. Ƙarfin kwasfa na iya tashi, faɗuwa, ko canja wurin ragowar. Haɗin kai na iya ƙaruwa (raƙuwa) ko raguwa ( gazawar haɗin gwiwa).

Ba duk PSA na silicone ba ne ke yin abu ɗaya. Bambance-bambancen sun sauko zuwa abun da ke ciki na polymer (methyl vs. methylphenyl), hanyar haɗin gwiwa (peroxide vs. ƙarin magani), da kuma rabon guduro MQ zuwa roba.

Aokai PTFE yana amfani da maki PSA na silicone da yawa a cikin kaset ɗin mu. Wannan jagorar yana bayanin abin da ke faruwa ga ƙarfin kwasfa da haɗin kai bayan yawan zafin jiki na kowane maki, da yadda za a zaɓi wanda ya dace don aikace-aikacenku.

Abin da ke Faruwa da Silicone PSA Karkashin Zafi - Yanayin Kasawa Biyu

Lokacin da ya tsufa a babban zafin jiki (200-250 ° C), silicone PSAs na iya fuskantar canje-canje biyu masu adawa:

1. Bayan hayewa (yana kaiwa ga karyewa)

Ƙungiyoyin ayyuka marasa amsa suna ci gaba da mayar da martani, suna ƙara yawan haɗin haɗin kai. Ƙarfin kwasfa na farko na iya tashi na ɗan lokaci, sa'an nan kuma ya faɗi da ƙarfi yayin da mannen ya zama mai ƙarfi sosai. Ƙarfin juzu'i yana bayyana yana ƙaruwa, amma riƙe ƙarfi da juriya na tasiri suna lalacewa. Fim ɗin m ya zama mai wuya kuma ya fashe.

2. Lalacewar kashin baya (yana haifar da asarar kwasfa da saura)

Kashin baya na polydimethylsiloxane yana jure hawan keke da sarkar sarkar. Ƙarfin kwasfa yana raguwa ci gaba. Manne zai iya canjawa wuri zuwa wurin (raguwa) ko kasa tare. Wannan ya zama ruwan dare a cikin ƙananan siliki na methyl siliki PSAs.

Maɓalli masu daidaitawa:

• Phenyl abun ciki (mafi girma = mafi kyawun juriya mai zafi)

• Crosslink yawa da nau'in warkewa (ƙarin magani vs. maganin peroxide)

• Ratio na MQ resin zuwa silicone roba

Rarraba Darajoji ta Tsarin Sinadarai

1. Standard polydimethylsiloxane (methyl-type silicone PSA)

• Riƙewar kwasfa bayan tsufa (200-250 ° C): Ƙarfin kwasfa yana ƙaruwa kaɗan da farko, sannan ya ragu. Bayan kwanaki 7 a 250 ° C, riƙewar kwasfa shine kawai 50-70% . Aiki yana faɗuwa da sauri a yanayin zafi mafi girma. Lalacewa ta zo daga cyclization na dimethyl siloxane kashin baya.

• Kwanciyar hankali na haɗin kai: Sifofin da aka warkar da peroxide (misali, KR-101) suna da ragowar masu farawa waɗanda ke haifar da rashin kulawa bayan warkewa - manne taurare da ƙwanƙwasa. Ƙarfin juzu'i na farko yana inganta, amma riƙe ikon ya ragu, kuma rashin daidaituwa yana faruwa a ƙarƙashin zafi. Siffofin da aka warkar da ƙari sun ɗan fi kyau amma har yanzu ana iyakance su ta wurin ƙarancin juriyar zafi na kashin baya na dimethyl.

2. Methylphenyl polysiloxane (maki mai juriya mai zafi)

• Riƙewar kwasfa bayan tsufa: Sarƙoƙin gefe na Phenyl suna ɓatar da tattarawar sassan dimethyl na yau da kullun kuma suna hana lalata hawan keke. Bayan kwanaki 7 a 250°C, ƙarfin kwasfa ya wuce 85% . Babban-phenyl formulations suna kula da kaddarorin kwasfa ko da a 260-288 ° C.

• Kwanciyar haɗin kai: Madalla. Ƙarfin ƙarfi yana canzawa kaɗan; riƙe riƙe da wutar lantarki ya wuce 80%. Layer na mannewa ya kasance mai sassauƙa na dogon lokaci ba tare da ƙullewa ko saura ba. Ƙarin da aka warkar da babban-phenyl maki sune mafi kyawun kwanciyar hankali na silicone PSA.

3. Musamman high-kwasfa da ƙananan kwasfa na al'ada maki

• High-peel maki (misali, Dow 7385, kwasfa na al'ada> 10N / 25mm): Babban MQ resin loading yana ba da kyakkyawan ƙarfin farko da ƙarfin kwasfa, amma a farashin juriya na zafi da kwanciyar hankali. Suna nuna digon kwasfa mafi girma bayan tsufa kuma suna da saurin saura saboda bazuwar zafi na guduro. Yi amfani kawai don aikace-aikacen ƙananan zafin jiki na tsaka-tsaki.

• Low-kwasfa, high-cohesion kariya film maki: High crosslink yawa ba da barga aikin kwasfa da kyakkyawan tsufa kwanciyar hankali, amma low farko taka. Bayan tsufa, sun kasance masu haɗin kai amma suna taurare, suna rage daidaituwa ga saman ƙasa.

Injin Crosslinking – Peroxide vs. Addition Cure (Same Methyl Base)

Ko da tare da polymer methyl iri ɗaya, hanyar warkewa tana canza yanayin tsufa sosai.

1. Peroxide-warke (na al'ada farkon ƙarni)

• Residual peroxide yana haifar da haɗin gwiwar da ba a sarrafa shi ba a lokacin babban zafin tsufa.

• Ƙarfin kwasfa da farko, sannan ya ruguje da ƙarfi.

• Haɗin kai yana tashi na ɗan lokaci, tare da ɓarnawa da rashin ƙarfi.

• Tsarin tsufa-zuwa-tsari ba shi da kyau.

2. Addition-cured (hydrosilylation curing)

• Cure ba ya haifar da samfurori; hanyar sadarwar crosslink ana iya sarrafawa daidai.

• Canje-canjen kadarorin bayan tsufa suna bin yanayin layin da ake iya faɗi.

• Nisa mafi girman kwasfa da kwanciyar hankali idan aka kwatanta da abubuwan da aka tsara na peroxide.

Jagorar Zaɓin Darajoji

Shawarar Aokai PTFE : Ga kowane tef ɗin PTFE wanda zai ga dorewar yanayin zafi sama da 200°C, ƙididdige ƙarin warkewar methylphenyl silicone PSA. Farashin gaba ya fi girma, amma yana hana gazawar filin da ya haifar da ragowar manne ko asarar haɗin gwiwa.

Takaitawa - Daidaita darajar PSA Silicone zuwa Buƙatar zafi

• Nau'in methyl silicone PSA (musamman peroxide-warke) ya dace kawai don amfani na ɗan lokaci ko ƙarancin zafi. Bayan kwanaki 7 a 250 ° C, yi tsammanin asarar kwasfa na 30-50% da yuwuwar ɓarna.

• Methylphenyl (high-phenyl) silicone PSA yana riƙe> 85% ƙarfin kwasfa da haɗin kai bayan tsufa iri ɗaya. Shi ne zaɓi don ci gaba da sabis na 200-250 ° C.

• Hanyar haɗin kai tana da mahimmanci: ƙarin magani (hydrosilylation) ya fi kwanciyar hankali fiye da maganin peroxide.

• Maki mai girma-peel yana musayar kwanciyar hankali ga tsufa don maƙarƙashiyar farko - guje musu a aikace-aikace masu zafi.

Don buƙatar haɗin kai mai zafi, Aokai PTFE yana amfani da ƙarin warkewar methylphenyl silicone PSAs. Za mu iya samar da bayanan riƙewar kwasfa bayan 1000h a 250 ° C akan buƙata.

Abubuwan fasaha da aka bayar ta Jiangsu Aokai New Materials Technology Co., Ltd.

Don cikakkun takaddun bayanan fasaha da mafita na al'ada don yadudduka masu zafin jiki na PTFE, kaset, bel ɗin raga, da ƙari:

• Mr. Guo: +86 18944819998

• Malam Liu: +86 13705266308

Yin biyayya ga ƙwararru da mutunci, muna ba da mafita na musamman na tsayawa ɗaya da sabis na tallace-tallace masu tunani.