{"id":2667,"date":"2026-07-30T14:35:53","date_gmt":"2026-07-30T14:35:53","guid":{"rendered":"https:\/\/www.fhysilicone.com\/?p=2667"},"modified":"2026-07-30T14:36:10","modified_gmt":"2026-07-30T14:36:10","slug":"lsr-paallystys-metallisissa-inserttien-pintakasittelyssa-tarttuvuus-ja-inserttien-rakenne","status":"publish","type":"post","link":"https:\/\/www.fhysilicone.com\/fi\/lsr-overmolding-on-metal-inserts-surface-treatment-bond-strength-and-insert-design\/","title":{"rendered":"LSR-p\u00e4\u00e4llystys metallisilla insertteill\u00e4: pintak\u00e4sittely, tartuntalujuus ja inserttien suunnittelu"},"content":{"rendered":"<p class=\"wp-block-paragraph\">Nestem\u00e4isen silikonikumin p\u00e4\u00e4llystysmenetelm\u00e4ll\u00e4 voidaan yhdist\u00e4\u00e4 j\u00e4ykk\u00e4 metallisis\u00e4osa joustavaan, l\u00e4mm\u00f6nkest\u00e4v\u00e4\u00e4n ja s\u00e4hk\u00f6\u00e4 erist\u00e4v\u00e4\u00e4n silikonikerrokseen yhdeksi valmiiksi komponentiksi. Menetelm\u00e4\u00e4 k\u00e4ytet\u00e4\u00e4n laajalti autoteollisuuden liittimiss\u00e4, l\u00e4\u00e4ketieteellisiss\u00e4 instrumenteissa, elektroniikkakoteloissa, t\u00e4rin\u00e4nvaimennusosissa, venttiileiss\u00e4, kahvoissa ja teollisuuden tiivistyskokoonpanoissa.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Onnistunut LSR:n ja metallin v\u00e4linen p\u00e4\u00e4llystys ei kuitenkaan riipu pelk\u00e4st\u00e4\u00e4n sopivan silikonilaadun valinnasta. Metalliseos, pinnan viimeistely, puhdistusmenetelm\u00e4, pohjamaalin levitys, insertin muoto, muotin suunnittelu ja kovettumisolosuhteet vaikuttavat kaikki lopulliseen tarttuvuuteen.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Komponentti voi vaikuttaa kelvolliselta muovauksen j\u00e4lkeen, mutta ep\u00e4onnistua vetokokeessa, l\u00e4mp\u00f6syklikokeessa, nestealtistuksessa tai toistuvassa k\u00e4yt\u00f6ss\u00e4. T\u00e4st\u00e4 syyst\u00e4 liimausmenetelm\u00e4 ja validointisuunnitelma tulisi laatia ennen tuotantoty\u00f6kalujen lopullista viimeistely\u00e4.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/www.fhysilicone.com\/wp-content\/uploads\/2026\/07\/LSR-Overmolding-on-Metal-Inserts-1024x576.png\" alt=\"\" class=\"wp-image-2668\" srcset=\"https:\/\/www.fhysilicone.com\/wp-content\/uploads\/2026\/07\/LSR-Overmolding-on-Metal-Inserts-1024x576.png 1024w, https:\/\/www.fhysilicone.com\/wp-content\/uploads\/2026\/07\/LSR-Overmolding-on-Metal-Inserts-300x169.png 300w, https:\/\/www.fhysilicone.com\/wp-content\/uploads\/2026\/07\/LSR-Overmolding-on-Metal-Inserts-768x432.png 768w, https:\/\/www.fhysilicone.com\/wp-content\/uploads\/2026\/07\/LSR-Overmolding-on-Metal-Inserts-1536x864.png 1536w, https:\/\/www.fhysilicone.com\/wp-content\/uploads\/2026\/07\/LSR-Overmolding-on-Metal-Inserts-18x10.png 18w, https:\/\/www.fhysilicone.com\/wp-content\/uploads\/2026\/07\/LSR-Overmolding-on-Metal-Inserts-600x338.png 600w, https:\/\/www.fhysilicone.com\/wp-content\/uploads\/2026\/07\/LSR-Overmolding-on-Metal-Inserts.png 1672w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Mit\u00e4 on metallisis\u00e4osien LSR-ylivalu?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">LSR-ylivalu on inserttivalumenetelm\u00e4, jossa valmiiksi valmistettu metallikomponentti asetetaan l\u00e4mmitetyn muotin sis\u00e4\u00e4n. Sen j\u00e4lkeen nestem\u00e4ist\u00e4 silikonikumia ruiskutetaan insertin valittujen alueiden ymp\u00e4rille, ja se kovetetaan muotin ontelossa.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Valmis osa yhdist\u00e4\u00e4 kaksi erilaista materiaalin ominaisuutta:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Metallinen insertti takaa j\u00e4ykkyyden, s\u00e4hk\u00f6njohtavuuden, kierteellisen kiinnityksen, mittavakauden tai rakenteellisen tuen.<\/li>\n\n\n\n<li>LSR-kerros tarjoaa tiivistyst\u00e4, eristyst\u00e4, iskunvaimennusta, joustavuutta, pitoa, t\u00e4rin\u00e4nvaimennusta tai ymp\u00e4rist\u00f6nsuojausta.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Yleisi\u00e4 metallisia ter\u00e4levyj\u00e4 ovat muun muassa:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Ruostumattomasta ter\u00e4ksest\u00e4 valmistetut putket ja kotelot<\/li>\n\n\n\n<li>Alumiinirungot ja kiinnikkeet<\/li>\n\n\n\n<li>Hiiliter\u00e4ksiset tapit ja levyt<\/li>\n\n\n\n<li>Messinkiliittimet<\/li>\n\n\n\n<li>Kuparijohdot<\/li>\n\n\n\n<li>Kierteitetyt holkit<\/li>\n\n\n\n<li>S\u00e4hk\u00f6liittimet<\/li>\n\n\n\n<li>Metalliset leimausosat, jotka on pinnoitettu tai p\u00e4\u00e4llystetty<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Silikoni voidaan kiinnitt\u00e4\u00e4 metalliin kemiallisesti, lukita mekaanisesti insertin ymp\u00e4rille tai kiinnitt\u00e4\u00e4 n\u00e4iden kahden menetelm\u00e4n yhdistelm\u00e4ll\u00e4.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Miksi LSR-muovi valetaan suoraan metallin p\u00e4\u00e4lle?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Suora p\u00e4\u00e4llystysmuovaus voi korvata useita toissijaisia kokoonpanovaiheita. Sen sijaan, ett\u00e4 silikoniosa valettaisiin erikseen ja asennettaisiin sen j\u00e4lkeen liimalla, kiinnikkeill\u00e4 tai kiinnittimill\u00e4, silikonista ja metallista voidaan muodostaa yksi yhten\u00e4inen komponentti.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Mahdollisia etuja ovat muun muassa:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>V\u00e4hemm\u00e4n kokoonpanovaiheita<\/li>\n\n\n\n<li>V\u00e4\u00e4r\u00e4nlaisen tiivisteen asennuksen riski on pienentynyt<\/li>\n\n\n\n<li>Parempi suoja kosteutta ja p\u00f6ly\u00e4 vastaan<\/li>\n\n\n\n<li>Parannettu t\u00e4rin\u00e4nkest\u00e4vyys<\/li>\n\n\n\n<li>Silikonin tasainen sijoittaminen<\/li>\n\n\n\n<li>Pienempi komponenttim\u00e4\u00e4r\u00e4<\/li>\n\n\n\n<li>Selke\u00e4mpi ulkomuoto<\/li>\n\n\n\n<li>Helpompi automatisointi suuremmilla tuotantom\u00e4\u00e4rill\u00e4<\/li>\n\n\n\n<li>Silikonin liukumisen tai py\u00f6rimisen riski on pienentynyt insertiss\u00e4<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Ylivalaminen on erityisen hy\u00f6dyllist\u00e4 silloin, kun silikonin on pysytt\u00e4v\u00e4 pysyv\u00e4sti kiinnittyneen\u00e4 metalliin puristuksen, vet\u00e4misen, v\u00e4\u00e4nt\u00e4misen tai l\u00e4mp\u00f6syklien aikana.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Kolme tapaa kiinnitt\u00e4\u00e4 LSR-pinnoite metalliseen ter\u00e4levyyn<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Pysyvyyden varmistamiseen on kolme p\u00e4\u00e4strategiaa.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1. Pohjamaalipohjainen kemiallinen kiinnitys<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Metallipinnalle levitet\u00e4\u00e4n sopiva pohjamaali ennen muovausta. LSR-muovin kovettumisen aikana pohjamaali parantaa silikonin ja metallipinnan v\u00e4list\u00e4 tarttuvuutta.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Pohjamaalij\u00e4rjestelm\u00e4t voivat tarjota vahvan tarttuvuuden moniin metalleihin, mutta prosessiin liittyy lis\u00e4vaatimuksia valvonnan suhteen:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Pintojen puhdistus<\/li>\n\n\n\n<li>Alustan valmistelu<\/li>\n\n\n\n<li>Pinnoitteen paksuus<\/li>\n\n\n\n<li>Kuivaus- tai paistoaika<\/li>\n\n\n\n<li>S\u00e4ilytysaika pohjamaalauksen j\u00e4lkeen<\/li>\n\n\n\n<li>Saastumisen ehk\u00e4isy<\/li>\n\n\n\n<li>K\u00e4ytt\u00f6- ja ymp\u00e4rist\u00f6asetukset<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Esimerkiksi Dow tarjoaa pohjamaaleja, jotka on erityisesti tarkoitettu LSR:n kiinnitt\u00e4miseen alumiini-, ruostumattomasta ter\u00e4ksest\u00e4 ja raudasta valmistettuihin alustoihin. Pohjamaalin valinta on aina sovitettava k\u00e4ytett\u00e4v\u00e4n silikonilaadun, metalliseoksen ja pintak\u00e4sittelyn mukaan. <a href=\"https:\/\/www.dow.com\/en-us\/pdp.silastic-dy-39-067-primer.02363704z.html\" rel=\"nofollow noopener\" target=\"_blank\">Dow SILASTIC DY 39-067 -pohjamaali<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">2. Itseliimautuva tai pohjamaaliton LSR<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Itsekiinnittyv\u00e4ss\u00e4 LSR-muovissa on tarttuvuutta edist\u00e4v\u00e4 kemiallinen koostumus, joka on suunniteltu kiinnittym\u00e4\u00e4n tiettyihin metalleihin tai teknisiin muoveihin muovausprosessin aikana.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">T\u00e4m\u00e4 menetelm\u00e4 mahdollistaa erillisen pohjamaalausvaiheen poistamisen sek\u00e4 ty\u00f6voiman, liuottimien k\u00e4yt\u00f6n ja pinnoituksen vaihteluiden v\u00e4hent\u00e4misen. \u201cPohjamaaliton\u201d ei kuitenkaan tarkoita, ett\u00e4 pinnan kunto ei olisi t\u00e4rke\u00e4\u00e4.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Tuotantolis\u00e4osan on edelleen oltava:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Puhdista<\/li>\n\n\n\n<li>Kuiva<\/li>\n\n\n\n<li>Ei sis\u00e4ll\u00e4 leikkuu\u00f6ljy\u00e4<\/li>\n\n\n\n<li>Ei sis\u00e4ll\u00e4 korroosionestoainetta<\/li>\n\n\n\n<li>Ei j\u00e4\u00e4 sormenj\u00e4lki\u00e4<\/li>\n\n\n\n<li>Yhteensopiva LSR-kovetusmenetelm\u00e4n kanssa<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Momentive kuvailee itsest\u00e4\u00e4n tarttuvia LSR-laatuja, jotka muodostavat pohjamaalittoman tartunnan metalleihin ja teknisiin muoveihin. Yhti\u00f6n teknisiss\u00e4 julkaisuissa todetaan my\u00f6s, ett\u00e4 t\u00e4ysi tartuntalujuus voi saavuttaa vasta j\u00e4lkikovettumisen tai varastoinnin j\u00e4lkeen, riippuen kyseisest\u00e4 laadusta. <a href=\"https:\/\/www.momentive.com\/content\/dam\/momentive\/en-us\/products\/tds\/silopren\/silopren-lsr-2750.pdf\" rel=\"nofollow noopener\" target=\"_blank\">Momentive Silopren LSR 2750<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">3. Mekaaninen lukitus<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Mekaanisessa lukituksessa kovettunutta silikonia pidet\u00e4\u00e4n paikallaan metallisen insertin muodon avulla.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Tyypillisi\u00e4 piirteit\u00e4 ovat:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>L\u00e4pivientirei\u00e4t<\/li>\n\n\n\n<li>Kolikkopelit<\/li>\n\n\n\n<li>Kiert\u00e4v\u00e4t urat<\/li>\n\n\n\n<li>Alaleikkaukset<\/li>\n\n\n\n<li>Ristirei\u00e4t<\/li>\n\n\n\n<li>Rei'itykset<\/li>\n\n\n\n<li>Uurretut alueet<\/li>\n\n\n\n<li>Olkap\u00e4\u00e4t<\/li>\n\n\n\n<li>Laipat<\/li>\n\n\n\n<li>Aukot, joiden l\u00e4pi silikoni voi virrata<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Mekaaninen lukitus on hy\u00f6dyllist\u00e4, kun kemiallisen tarttuvuuden luotettavuus on ep\u00e4varmaa tai kun sovelluksessa tarvitaan lis\u00e4kest\u00e4vyytt\u00e4 irtoamista, v\u00e4\u00e4ntymist\u00e4 tai kuoriutumista vastaan.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Kriittisten komponenttien osalta kemiallisen tarttuvuuden ja mekaanisen lukituksen yhdist\u00e4v\u00e4 hybridirakenne tarjoaa yleens\u00e4 kaikkein kest\u00e4vimm\u00e4n ratkaisun.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Alustapohjainen, alustaton vai mekaaninen kiinnitys?<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><th>Liimausmenetelm\u00e4<\/th><th>T\u00e4rkeimm\u00e4t edut<\/th><th>T\u00e4rkeimm\u00e4t rajoitukset<\/th><th>Soveltuvat k\u00e4ytt\u00f6kohteet<\/th><\/tr><tr><td>Alustapohjainen liimaus<\/td><td>Laaja alustojen yhteensopivuus ja potentiaalisesti vahva kemiallinen tarttuvuus<\/td><td>Lis\u00e4pinnoitus-, kuivaus- ja k\u00e4sittelytoimenpiteet<\/td><td>Teollisuustiivisteet, metallikotelot, rullat ja liittimet<\/td><\/tr><tr><td>Itseliimautuva LSR<\/td><td>V\u00e4hemm\u00e4n k\u00e4sittelyvaiheita ja helpompi automatisointi<\/td><td>Tarkka metallin, pinnoitteen ja LSR:n yhdistelm\u00e4 on vahvistettava<\/td><td>Suurivolyymiset inserttivaletut komponentit<\/td><\/tr><tr><td>Mekaaninen lukitus<\/td><td>Pintakemian vaikutuksesta riippuvaisempi<\/td><td>Vaatii riitt\u00e4v\u00e4sti tilaa ja sopivan insertin geometrian<\/td><td>Kahvat, l\u00e4pivientirenkaat, vahvistetut tiivisteet ja vetolujuudet osat<\/td><\/tr><tr><td>Hybridipid\u00e4tys<\/td><td>Yhdist\u00e4\u00e4 kemiallisen ja fysikaalisen pid\u00e4tt\u00e4misen<\/td><td>Monimutkaisempi inserttien ja ty\u00f6kalujen suunnittelu<\/td><td>Turvallisuuden kannalta kriittiset tai suurille kuormituksille altistuvat kokoonpanot<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Paras menetelm\u00e4 riippuu tuotteen k\u00e4ytt\u00f6ymp\u00e4rist\u00f6st\u00e4, vaaditusta kiinnityslujuudesta, tuotantom\u00e4\u00e4r\u00e4st\u00e4 ja k\u00e4ytett\u00e4viss\u00e4 olevasta kiinnikkeen geometriasta.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Metallin valinta ja pinnan kunto<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Sama LSR-laatu voi tarttua eri tavalla kahteen ulkon\u00e4\u00f6lt\u00e4\u00e4n identtiseen inserttiin. Pienet erot metalliseoksen koostumuksessa, pinnoituksessa, oksidikerroksen tilassa, ty\u00f6st\u00f6voiteluaineessa tai pintak\u00e4sittelyss\u00e4 voivat vaikuttaa tarttuvuuteen merkitt\u00e4v\u00e4sti.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Alumiini<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Alumiini on kevyt ja helppo ty\u00f6st\u00e4\u00e4, mutta sen luonnollinen oksidikerros ja pintak\u00e4sittelyt voivat vaihdella.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">T\u00e4rkeit\u00e4 muuttujia ovat muun muassa:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Seos ja karkaisu<\/li>\n\n\n\n<li>Koneistettu, valettu tai leimattu kunto<\/li>\n\n\n\n<li>Luonnollinen, anodisoitu tai konversiopinnoitettu pinta<\/li>\n\n\n\n<li>Leikkausnesteen j\u00e4\u00e4m\u00e4t<\/li>\n\n\n\n<li>Oksidikerroksen paksuus<\/li>\n\n\n\n<li>Pinnan karheus<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Anodisointi voi parantaa kest\u00e4vyytt\u00e4, mutta tarttuvuus on varmistettava ottaen huomioon tarkka anodisointityyppi, v\u00e4ri, tiivistysolosuhteet ja valmistaja.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Ruostumaton ter\u00e4s<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Ruostumatonta ter\u00e4st\u00e4 k\u00e4ytet\u00e4\u00e4n yleisesti l\u00e4\u00e4ketieteen, elintarviketeollisuuden ja teollisuuden komponenteissa. Sen passiivinen pinta takaa korroosionkest\u00e4vyyden, mutta voi my\u00f6s vaikuttaa tarttuvuuteen riippuen k\u00e4ytetyist\u00e4 puhdistus- ja aktivointimenetelmist\u00e4.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Erittelyss\u00e4 tulisi m\u00e4\u00e4ritell\u00e4 seuraavat seikat:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Ruostumattoman ter\u00e4ksen laatu<\/li>\n\n\n\n<li>Pinnan viimeistely<\/li>\n\n\n\n<li>Passivointiprosessi<\/li>\n\n\n\n<li>Kiillotustila<\/li>\n\n\n\n<li>Puhdistusmenetelm\u00e4<\/li>\n\n\n\n<li>Kaikki leimaamisen tai koneistuksen yhteydess\u00e4 k\u00e4ytetyt voiteluaineet<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Hiiliter\u00e4s<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Hiiliter\u00e4s tarjoaa vahvat mekaaniset ominaisuudet edullisemmin, mutta ruosteenesto\u00f6ljyn k\u00e4ytt\u00f6\u00e4 ja korroosiota on hallittava.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Maali, pinnoitus tai konversiopinnoitteet voivat suojata insertti\u00e4, mutta LSR tarttuu pinnoitteeseen \u2013 ei suoraan pohjater\u00e4kseen. Pinnoitteen tarttuvuus on siten osa koko kiinnitysj\u00e4rjestelm\u00e4\u00e4.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Messinki ja kupari<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Messinki- ja kuparisis\u00e4osia k\u00e4ytet\u00e4\u00e4n usein s\u00e4hk\u00f6komponenteissa. Niiden pinnan hapettumista, pinnoitusta, puristuksen voiteluaineita ja varastointiolosuhteita on valvottava huolellisesti.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Yhteensopivuustestaus on t\u00e4rke\u00e4\u00e4, koska itse insertti voi sis\u00e4lt\u00e4\u00e4 nikkeli\u00e4, tinaa, hopeaa tai muuta pinnoitetta.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Metalliset pinnoitetut insertit<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Kun insertti\u00e4 levitet\u00e4\u00e4n, on vastattava seuraaviin kysymyksiin:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Mist\u00e4 materiaalista pinnoite on tehty?<\/li>\n\n\n\n<li>Mik\u00e4 on m\u00e4\u00e4ritelty pinnoitteen paksuus?<\/li>\n\n\n\n<li>Onko ylimuovattu alue kokonaan pinnoitettu?<\/li>\n\n\n\n<li>K\u00e4ytet\u00e4\u00e4nk\u00f6 pinnoituksen j\u00e4lkeist\u00e4 voiteluainetta?<\/li>\n\n\n\n<li>Voiko pinnoituspalvelun toimittaja vaihtua ilman hyv\u00e4ksynt\u00e4\u00e4?<\/li>\n\n\n\n<li>Pysyyk\u00f6 pinnoite vakaana LSR-muovausl\u00e4mp\u00f6tiloissa?<\/li>\n\n\n\n<li>Tarttuuko pinnoite riitt\u00e4v\u00e4n lujasti perusmetalliin?<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Vahva LSR:n ja pinnoitteen v\u00e4linen sidos ei voi korvata pinnoitteen ja alla olevan metallin v\u00e4list\u00e4 heikkoa tarttuvuutta.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Pintak\u00e4sittelyn ty\u00f6nkulku luotettavaa liimauslujuutta varten<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Pinnan esik\u00e4sittely on yksi LSR-muovin ja metallin v\u00e4lisen p\u00e4\u00e4llystysmuovauksen t\u00e4rkeimmist\u00e4 vaiheista.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Vaihe 1: M\u00e4\u00e4rit\u00e4 tuotantopinta<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Prototyyppien testauksessa tulisi k\u00e4ytt\u00e4\u00e4 osia, jotka vastaavat lopullisen tuotannon metalliseosta, pintak\u00e4sittely\u00e4, pinnoitusta ja puhdistusprosessia.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">K\u00e4sin kiillotetun laboratorion\u00e4ytteen testaaminen ei riit\u00e4, jos tuotantokappaleet aiotaan puristaa, passivoida, anodisoida tai pinnoittaa toisen toimittajan toimesta.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Vaihe 2: \u00d6ljyn ja ep\u00e4puhtauksien poistaminen<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Metallipinnoilla ei saa olla:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Koneistus\u00f6ljy<\/li>\n\n\n\n<li>Leimausvoiteluaine<\/li>\n\n\n\n<li>Ruosteenesto\u00f6ljy<\/li>\n\n\n\n<li>Kiillotusaine<\/li>\n\n\n\n<li>P\u00f6ly<\/li>\n\n\n\n<li>Silikonisaasteet<\/li>\n\n\n\n<li>Sormenj\u00e4ljet<\/li>\n\n\n\n<li>Liimaj\u00e4\u00e4m\u00e4t<\/li>\n\n\n\n<li>Pakkausj\u00e4tteet<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Puhdistusprosessin on oltava yhteensopiva metallin, pinnoitteen, pohjamaalin ja lopputuotteen viranomaisvaatimusten kanssa.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Vaihe 3: Lis\u00e4\u00e4 pinta-alaa tarvittaessa<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Eritt\u00e4in sileille metallipinnoille voi olla hy\u00f6ty\u00e4 hallitusta karhennuksesta.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Mahdollisia prosesseja ovat muun muassa:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Hiekkapuhallus<\/li>\n\n\n\n<li>Lasikuulapuhallus<\/li>\n\n\n\n<li>Hienomekaaninen hionta<\/li>\n\n\n\n<li>Laserteksturointi<\/li>\n\n\n\n<li>Kemiallinen sy\u00f6vytys<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Pinnan karhentaminen voi lis\u00e4t\u00e4 pinta-alaa ja edist\u00e4\u00e4 mekaanista kiinnittymist\u00e4, mutta liiallinen karheus voi ker\u00e4t\u00e4 ep\u00e4puhtauksia, vahingoittaa pinnoitetta tai aiheuttaa ilmataskuja.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Wackerin k\u00e4sittelyohjeiden mukaan pohjustettavien pintojen tulee olla kuivia ja \u00f6ljy- ja rasvattomia, ja eritt\u00e4in sile\u00e4t pinnat saatetaan joutua karhentamaan ennen pohjamaalin levitt\u00e4mist\u00e4. <a href=\"https:\/\/www.wacker.com\/h\/en-bg\/medias\/6709-EN.pdf\" rel=\"nofollow noopener\" target=\"_blank\">Wackerin kiinte\u00e4n ja nestem\u00e4isen silikonikumin k\u00e4sittelyopas<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Vaihe 4: Pinnan aktivointi- tai muuntok\u00e4sittely<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Metallista ja k\u00e4ytt\u00f6tarkoituksesta riippuen k\u00e4sittelyyn voi kuulua:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Plasman aktivointi<\/li>\n\n\n\n<li>Koronaviruksen hoito<\/li>\n\n\n\n<li>Kemiallinen konversiopinnoite<\/li>\n\n\n\n<li>Anodisointi<\/li>\n\n\n\n<li>Passivointi<\/li>\n\n\n\n<li>Laserpuhdistus<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">N\u00e4m\u00e4 k\u00e4sittelyt on validoitava valitun LSR- ja alukej\u00e4rjestelm\u00e4n kanssa. K\u00e4sittely, joka parantaa korroosionkest\u00e4vyytt\u00e4, ei automaattisesti paranna silikonin tarttuvuutta.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Vaihe 5: Levit\u00e4 pohjamaalia oikein<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Kun pohjamaalia tarvitaan, se tulisi yleens\u00e4 levitt\u00e4\u00e4 ohuena, tasaisena kerroksena k\u00e4ytt\u00e4en asianmukaista menetelm\u00e4\u00e4, kuten:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Ruiskutus<\/li>\n\n\n\n<li>Kastelu<\/li>\n\n\n\n<li>Harjaus<\/li>\n\n\n\n<li>Automaattinen annostelu<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Liian pieni m\u00e4\u00e4r\u00e4 pohjamaalia voi johtaa ep\u00e4t\u00e4ydelliseen peittoon. Liian suuri m\u00e4\u00e4r\u00e4 pohjamaalia voi aiheuttaa kertymi\u00e4, ep\u00e4tasaista kovettumista tai heikkoja pohjamaalin sis\u00e4kerroksia.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Alustetta ei saa s\u00e4ilytt\u00e4\u00e4 seuraavien aineiden l\u00e4heisyydess\u00e4:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>S\u00e4hk\u00f6liittimet<\/li>\n\n\n\n<li>Langat, joiden on pysytt\u00e4v\u00e4 puhtaina<\/li>\n\n\n\n<li>Hitsausalueet<\/li>\n\n\n\n<li>Kosmeettiset metallipinnat<\/li>\n\n\n\n<li>Muotin sulkeutumispinnat<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Vaihe 6: Kuivaa tai paista pohjamaali<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Kuivumisaika, l\u00e4mp\u00f6tila ja enimm\u00e4iss\u00e4ilytysaika on m\u00e4\u00e4ritett\u00e4v\u00e4 pohjamaalin valmistajan teknisten tietojen mukaisesti.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Jotkut pohjamaalit kuivuvat ilmakuivauksella, kun taas toiset saattavat vaatia l\u00e4mp\u00f6aktivointia tai uunikuivausta. Suuret ylimuovausalueet saattavat my\u00f6s vaatia lis\u00e4valmistelua, jotta silikonin virtaus ruiskutuksen aikana ei vahingoita pohjamaalikalvoa.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Vaihe 7: Suojaa k\u00e4sitellyt insertit<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">K\u00e4sittelyn j\u00e4lkeen inserttej\u00e4 tulee k\u00e4sitell\u00e4 puhtailla k\u00e4sineill\u00e4 ja s\u00e4ilytt\u00e4\u00e4 valvotuissa olosuhteissa.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">T\u00e4rkeimpi\u00e4 valvontatoimenpiteit\u00e4 ovat:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Hoidon ja muovauksen v\u00e4linen enimm\u00e4isaika<\/li>\n\n\n\n<li>L\u00e4mp\u00f6tila ja kosteus<\/li>\n\n\n\n<li>P\u00f6lysuojaus<\/li>\n\n\n\n<li>Pakkausmateriaali<\/li>\n\n\n\n<li>Tarjottimen puhtaus<\/li>\n\n\n\n<li>Er\u00e4n tunniste<\/li>\n\n\n\n<li>\u201dEnsimm\u00e4iseksi sis\u00e4\u00e4n, ensimm\u00e4iseksi ulos\u201d -periaate<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">LSR:n kovettumisen est\u00e4misen ehk\u00e4iseminen<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Useimmissa teknisiss\u00e4 LSR-materiaaleissa k\u00e4ytet\u00e4\u00e4n platinakatalysoitua additiovakautusta. Tietyt aineet voivat h\u00e4irit\u00e4 kovettumisreaktiota metallin ja silikonin rajapinnalla.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Parantumisen est\u00e4misen mahdollisia syit\u00e4 ovat muun muassa:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Rikki\u00e4 sis\u00e4lt\u00e4v\u00e4t materiaalit<\/li>\n\n\n\n<li>Aamiinit<\/li>\n\n\n\n<li>Joitakin liimoja<\/li>\n\n\n\n<li>Tietyt kumiseokset<\/li>\n\n\n\n<li>Organotina-kovetetut materiaalit<\/li>\n\n\n\n<li>Contaminated release agents<\/li>\n\n\n\n<li>Processing oils<\/li>\n\n\n\n<li>Some paints and coatings<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The result may be soft, sticky or uncured silicone at the interface even when the rest of the molded component appears fully cured.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Momentive recommends compatibility testing for all materials that contact self-bonding LSR, including painted surfaces, and specifically identifies several chemical families that may cause cure inhibition. <a href=\"https:\/\/www.momentive.com\/content\/dam\/momentive\/ko-kr\/products\/tds\/silopren-lim9071et.pdf\" rel=\"nofollow noopener\" target=\"_blank\">Momentive Silopren LIM 9071 ET Technical Data<\/a><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Metal Insert Design Rules<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Good insert geometry can improve adhesion, molding stability and long-term reliability.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Add Mechanical Retention Features<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Whenever space allows, include features through which the silicone can flow and cure.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Esimerkkej\u00e4 ovat:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Holes through a metal flange<\/li>\n\n\n\n<li>Slots along the bonding area<\/li>\n\n\n\n<li>A circumferential groove around a pin<\/li>\n\n\n\n<li>A shoulder behind the silicone layer<\/li>\n\n\n\n<li>Knurled or textured retention zones<\/li>\n\n\n\n<li>Opposing undercuts<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Mechanical retention is especially useful when the assembly will experience peeling, twisting or repeated vibration.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Avoid Sharp Metal Edges<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Sharp edges can cut the silicone during demolding, assembly or use. They also concentrate stress at the edge of the bond.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Use suitable radii or chamfers where the silicone transitions from the metal surface.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Control Silicone Wall Thickness<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Extremely thin silicone may tear, fail to fill or provide insufficient sealing movement. Excessively thick silicone may increase cure time, material cost and dimensional variation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The wall thickness should be based on:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Vaadittu joustavuus<\/li>\n\n\n\n<li>Compression<\/li>\n\n\n\n<li>Tear risk<\/li>\n\n\n\n<li>Flow length<\/li>\n\n\n\n<li>Muotinpoistomenetelm\u00e4<\/li>\n\n\n\n<li>Bonding area<\/li>\n\n\n\n<li>Product tolerance<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Gradual thickness transitions are generally more reliable than sudden changes.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Design for Balanced Flow<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Gate position should allow the LSR to fill around the insert without trapping air or moving the insert.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Poor flow design can cause:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Weld lines<\/li>\n\n\n\n<li>Air pockets<\/li>\n\n\n\n<li>Incomplete coverage<\/li>\n\n\n\n<li>Exposed metal<\/li>\n\n\n\n<li>Primer damage<\/li>\n\n\n\n<li>Insert movement<\/li>\n\n\n\n<li>Uneven bond strength<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Vents should be placed near the final filling areas. Because LSR has very low viscosity, vent dimensions and shut-offs must be carefully controlled to prevent excessive flash.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Support the Insert in the Mold<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The insert must remain stable during mold closing and injection.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Locating features may include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Pins<\/li>\n\n\n\n<li>Nests<\/li>\n\n\n\n<li>Magnetic loading fixtures<\/li>\n\n\n\n<li>Spring-loaded supports<\/li>\n\n\n\n<li>Vacuum-assisted holding<\/li>\n\n\n\n<li>Robotic loading fixtures<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The insert should not rock, bend or float under injection pressure.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Protect Functional Metal Areas<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Threads, electrical contacts, sealing faces and welding zones may need to remain free from silicone and primer.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">These areas can be protected by:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Precision mold shut-offs<\/li>\n\n\n\n<li>Removable masking<\/li>\n\n\n\n<li>Insert caps<\/li>\n\n\n\n<li>Dedicated locating surfaces<\/li>\n\n\n\n<li>Secondary cleaning, if permitted<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Masking should not introduce contamination or leave residue on the bonding area.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Consider Thermal Expansion<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Metal and silicone respond differently to temperature changes. Repeated heating and cooling can generate stress at the interface.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Long, continuous bond lines may benefit from:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Flexible silicone transition zones<\/li>\n\n\n\n<li>Rounded bond edges<\/li>\n\n\n\n<li>Mechanical locking features<\/li>\n\n\n\n<li>Reduced peel loading<\/li>\n\n\n\n<li>Adequate silicone thickness<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Tooling Considerations<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Metal-insert overmolding requires more tooling controls than molding a silicone-only part.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Important tooling features include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Accurate insert location<\/li>\n\n\n\n<li>Repeatable shut-off pressure<\/li>\n\n\n\n<li>Flash control around the insert<\/li>\n\n\n\n<li>Venting at flow ends<\/li>\n\n\n\n<li>Easy insert loading<\/li>\n\n\n\n<li>Safe removal of the finished part<\/li>\n\n\n\n<li>Protection against insert scratching<\/li>\n\n\n\n<li>Sensor confirmation for automated loading<\/li>\n\n\n\n<li>Prevention of incorrect insert orientation<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">If the insert has dimensional variation, the tooling must accommodate the expected tolerance without losing shut-off control.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A small variation in insert thickness can create:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Silicone flash<\/li>\n\n\n\n<li>Metal deformation<\/li>\n\n\n\n<li>Mold damage<\/li>\n\n\n\n<li>Incomplete closure<\/li>\n\n\n\n<li>Unstable silicone coverage<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">For this reason, insert tolerances should be reviewed together with mold tolerances during DFM.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">LSR Processing Variables That Affect Adhesion<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Even with the correct surface treatment and insert design, molding conditions can influence bond strength.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Mold Temperature<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The insert and mold must reach a temperature that supports LSR curing and adhesion development. A cold or excessively massive insert may slow curing at the interface.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Cure Time<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Insufficient cure time may produce acceptable-looking parts with weak or incomplete interfacial bonding.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Injection Speed and Pressure<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">High flow forces can move the insert, trap air or damage a primer layer. Very low speed may produce premature curing or incomplete filling.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Insert Preheating<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Preheating may improve temperature uniformity and reduce cure variation, but the required temperature must be established through trials.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Post-Curing<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Some LSR grades develop additional bond strength after thermal post-curing or room-temperature storage. Post-curing may also be required for selected regulatory or performance requirements.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The post-curing decision should be based on:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Material supplier recommendations<\/li>\n\n\n\n<li>Required bond strength<\/li>\n\n\n\n<li>Volatile limits<\/li>\n\n\n\n<li>Regulatory requirements<\/li>\n\n\n\n<li>Final application temperature<\/li>\n\n\n\n<li>Tuotantokustannukset<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">How Is LSR-to-Metal Bond Strength Tested?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Visual inspection alone cannot confirm bond reliability.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">90-Degree Peel Testing<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A flexible silicone strip is peeled from a rigid substrate at a controlled angle and speed. The force is normally reported relative to the width of the bonded strip.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">ISO 813:2019 specifies a 90-degree peel method for evaluating rubber bonded to a rigid substrate. <a href=\"https:\/\/www.iso.org\/standard\/77421.html\" rel=\"nofollow noopener\" target=\"_blank\">ISO 813:2019<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Comparative Peel Testing<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">ASTM D903 provides a method for comparing peel or stripping strength under defined specimen preparation and testing conditions. <a href=\"https:\/\/store.astm.org\/d0903-98r17.html\" rel=\"nofollow noopener\" target=\"_blank\">ASTM D903<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Pull-Off or Tensile Testing<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The silicone is pulled away from the insert perpendicular to the bonding surface. This can be useful for buttons, plugs, studs and circular inserts.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Pull-Out Testing<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The metal insert is pulled from the molded silicone body. This method evaluates the combined effect of chemical adhesion and mechanical locking.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Torque Testing<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The metal insert is rotated relative to the silicone. This is useful for knobs, shafts, handles and threaded components.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Functional Part Testing<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A custom fixture applies the load expected in the final product, such as:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Repeated bending<\/li>\n\n\n\n<li>Tiivisteen puristus<\/li>\n\n\n\n<li>Cable pulling<\/li>\n\n\n\n<li>Connector insertion<\/li>\n\n\n\n<li>Valve cycling<\/li>\n\n\n\n<li>T\u00e4rin\u00e4<\/li>\n\n\n\n<li>Painekoe<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Whenever possible, standard test plaques should be supplemented with tests on the actual molded component.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Bond Failure Modes<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Bond strength values should be evaluated together with the observed failure mode.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Adhesive Failure<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The silicone separates cleanly from the metal surface.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Possible causes include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Surface contamination<\/li>\n\n\n\n<li>Incorrect primer<\/li>\n\n\n\n<li>Insufficient primer coverage<\/li>\n\n\n\n<li>Incompatible metal coating<\/li>\n\n\n\n<li>Poor cure at the interface<\/li>\n\n\n\n<li>Insufficient surface activation<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Cohesive Failure<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The silicone tears while a layer remains bonded to the metal.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Cohesive failure usually indicates that the interface is stronger than the silicone material in the tested area.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Mixed Failure<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Part of the silicone tears, while another portion separates from the metal.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Mixed failure may indicate inconsistent surface treatment, uneven primer coverage or variable molding conditions.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Environmental Validation<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Initial bond strength is only one part of qualification. The assembly should also be tested after exposure to its expected operating environment.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Possible validation conditions include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>High-temperature aging<\/li>\n\n\n\n<li>Low-temperature exposure<\/li>\n\n\n\n<li>L\u00e4mp\u00f6syklit<\/li>\n\n\n\n<li>Temperature and humidity aging<\/li>\n\n\n\n<li>Water immersion<\/li>\n\n\n\n<li>Oil or fuel exposure<\/li>\n\n\n\n<li>Cleaning chemicals<\/li>\n\n\n\n<li>Salt spray<\/li>\n\n\n\n<li>UV exposure<\/li>\n\n\n\n<li>Steam sterilization<\/li>\n\n\n\n<li>Gamma sterilization<\/li>\n\n\n\n<li>Ethylene oxide sterilization<\/li>\n\n\n\n<li>Repeated mechanical cycling<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The correct tests depend on the application. Automotive, medical, food-contact and electronic products may require different material grades and qualification protocols.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Common Problems and Corrective Actions<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td>Problem<\/td><td>Possible cause<\/td><td>Corrective action<\/td><\/tr><tr><td>Silicone peels cleanly from metal<\/td><td>Oil, fingerprints, incorrect primer or incompatible finish<\/td><td>Improve cleaning and validate the complete material system<\/td><\/tr><tr><td>Silicone remains sticky near the insert<\/td><td>Cure inhibition from coating, lubricant or contamination<\/td><td>Conduct compatibility testing and remove the contamination source<\/td><\/tr><tr><td>Bond strength varies between lots<\/td><td>Metal finish or primer process variation<\/td><td>Lock the insert specification and improve traceability<\/td><\/tr><tr><td>Strong initial bond but weak after aging<\/td><td>Corrosion, fluid penetration or thermal stress<\/td><td>Review surface protection, bond edge and environmental resistance<\/td><\/tr><tr><td>Silicone tears at the metal edge<\/td><td>Sharp edge or high peel stress<\/td><td>Add radii and reduce stress concentration<\/td><\/tr><tr><td>Insert moves during molding<\/td><td>Inadequate fixture support<\/td><td>Improve mold location and insert retention<\/td><\/tr><tr><td>Flash forms around the insert<\/td><td>Insert tolerance or shut-off variation<\/td><td>Tighten insert tolerances and redesign the shut-off<\/td><\/tr><tr><td>Silicone sticks to unwanted mold areas<\/td><td>Self-bonding material or release-control problem<\/td><td>Review mold coating and release strategy<\/td><\/tr><tr><td>Primer contaminates electrical contacts<\/td><td>Poor masking or uncontrolled spraying<\/td><td>Add targeted coating and protected handling fixtures<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">Quality Control for Production<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A stable production process should control both the incoming metal inserts and the overmolding operation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Suositeltavia hallintatoimenpiteit\u00e4 ovat muun muassa:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Approved metal alloy and supplier<\/li>\n\n\n\n<li>Surface-finish specification<\/li>\n\n\n\n<li>Plating or treatment certificate<\/li>\n\n\n\n<li>Incoming visual inspection<\/li>\n\n\n\n<li>Cleanliness verification<\/li>\n\n\n\n<li>Primer lot and expiration tracking<\/li>\n\n\n\n<li>Primer mixing and application records<\/li>\n\n\n\n<li>Kuivaus- tai paistoaika<\/li>\n\n\n\n<li>Maximum treated-insert storage time<\/li>\n\n\n\n<li>LSR batch traceability<\/li>\n\n\n\n<li>Mold temperature monitoring<\/li>\n\n\n\n<li>Cure-time records<\/li>\n\n\n\n<li>Insert-presence detection<\/li>\n\n\n\n<li>Mitatarkastus<\/li>\n\n\n\n<li>Periodic bond-strength testing<\/li>\n\n\n\n<li>Failure-mode recording<\/li>\n\n\n\n<li>Environmental validation by production lot when required<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A water-break test, surface-energy check or visual primer inspection may help monitor the process, but these methods should not replace actual bond testing.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Prototype and Pilot Production Plan<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A practical development program normally includes four stages.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Stage 1: Material Screening<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Test combinations of:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Metal alloys<\/li>\n\n\n\n<li>Surface finishes<\/li>\n\n\n\n<li>Puhdistusmenetelm\u00e4t<\/li>\n\n\n\n<li>Primer systems<\/li>\n\n\n\n<li>Self-bonding LSR grades<\/li>\n\n\n\n<li>Mechanical retention designs<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Stage 2: Prototype Insert Molding<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Produce representative parts using production-intent inserts and evaluate:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Filling<\/li>\n\n\n\n<li>Insert movement<\/li>\n\n\n\n<li>Flash<\/li>\n\n\n\n<li>Silicone coverage<\/li>\n\n\n\n<li>Demolding<\/li>\n\n\n\n<li>Initial adhesion<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Stage 3: Bond and Environmental Testing<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Measure bond strength before and after relevant aging conditions. Record both force and failure mode.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Stage 4: Pilot Production<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Run a controlled pilot batch to confirm:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Insert-loading repeatability<\/li>\n\n\n\n<li>Syklin kesto<\/li>\n\n\n\n<li>Primer-process capability<\/li>\n\n\n\n<li>Dimensional stability<\/li>\n\n\n\n<li>Bond consistency<\/li>\n\n\n\n<li>Inspection method<\/li>\n\n\n\n<li>Packaging and storage<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Pilot production is particularly important when inserts are supplied by an external metal stamping, machining, anodizing or plating company.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Cost Drivers<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The cost of an LSR-overmolded metal component depends on more than silicone weight.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Major cost factors include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Insert material and machining<\/li>\n\n\n\n<li>Plating or surface treatment<\/li>\n\n\n\n<li>Cleaning requirements<\/li>\n\n\n\n<li>Pohjamaalin levitys<\/li>\n\n\n\n<li>Insert-loading method<\/li>\n\n\n\n<li>Cavity quantity<\/li>\n\n\n\n<li>Mold shut-off complexity<\/li>\n\n\n\n<li>Silicone grade<\/li>\n\n\n\n<li>Syklin kesto<\/li>\n\n\n\n<li>J\u00e4lkikovetus<\/li>\n\n\n\n<li>Bond testing<\/li>\n\n\n\n<li>Environmental validation<\/li>\n\n\n\n<li>Tuotantom\u00e4\u00e4r\u00e4<\/li>\n\n\n\n<li>J\u00e4ljitett\u00e4vyysvaatimukset<\/li>\n\n\n\n<li>Packaging and contamination control<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Self-bonding LSR may reduce primer-related labor, but the material cost and qualification requirements should be compared with the complete production process\u2014not evaluated in isolation.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">RFQ Checklist for LSR Overmolding on Metal<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">To receive an accurate quotation, provide:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>3D-CAD-tiedosto<\/li>\n\n\n\n<li>2D-piirros<\/li>\n\n\n\n<li>Metal alloy and temper<\/li>\n\n\n\n<li>Insert manufacturing process<\/li>\n\n\n\n<li>Pinnan karheus<\/li>\n\n\n\n<li>Plating, anodizing or passivation details<\/li>\n\n\n\n<li>Areas that require silicone bonding<\/li>\n\n\n\n<li>Areas that must remain free of silicone<\/li>\n\n\n\n<li>Required silicone hardness<\/li>\n\n\n\n<li>Silikoniv\u00e4ri<\/li>\n\n\n\n<li>Regulatory requirements<\/li>\n\n\n\n<li>K\u00e4ytt\u00f6l\u00e4mp\u00f6tila<\/li>\n\n\n\n<li>Chemical and fluid exposure<\/li>\n\n\n\n<li>Required bond-strength method<\/li>\n\n\n\n<li>Minimum pull, peel or torque requirement<\/li>\n\n\n\n<li>Preferred failure mode<\/li>\n\n\n\n<li>Mitatoleranssit<\/li>\n\n\n\n<li>Cosmetic requirements<\/li>\n\n\n\n<li>Expected annual volume<\/li>\n\n\n\n<li>Pilot-order quantity<\/li>\n\n\n\n<li>Required inspection report<\/li>\n\n\n\n<li>Packaging and cleanliness requirements<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">If the metal supplier or surface-treatment process may change, this should be discussed before validation. A supplier change can alter adhesion even when the drawing dimensions remain unchanged.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Usein kysyttyj\u00e4 kysymyksi\u00e4<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Does LSR always require primer to bond to metal?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">No. Some self-bonding LSR grades can bond directly to compatible metals. However, the exact metal alloy, surface finish, coating and molding conditions must be validated.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Can LSR bond to stainless steel?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Yes. LSR can be bonded to stainless steel using a compatible primer or a qualified self-bonding material. Cleaning, passivation and surface finish can influence the result.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Can LSR bond to anodized aluminum?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">It may bond successfully, but the anodizing type, color, sealing process and surface condition must be tested. Different anodizing suppliers can produce different adhesion results.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Is sandblasting enough to create a reliable bond?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Not necessarily. Sandblasting increases roughness but does not remove every contaminant or provide chemical adhesion. Cleaning, primer selection and process validation may still be required.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">What is considered good bond strength?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">There is no universal value. The required force depends on the bonding area, silicone hardness, loading direction, product geometry and service environment. The customer should define a functional requirement and test method.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Is cohesive failure better than adhesive failure?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Cohesive failure generally indicates that the metal-to-silicone interface is stronger than the silicone in the tested region. However, the total measured force must still meet the application requirement.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Should mechanical locking be used if chemical bonding is available?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Mechanical locking is recommended when the geometry permits, especially for parts exposed to pulling, twisting, vibration or safety-critical loads. It provides additional protection against surface-process variation.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Can plated inserts be overmolded?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Yes, but the complete system must be tested. The LSR bonds to the plating surface, so plating adhesion, thickness, porosity and post-plating contamination must be controlled.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Does bond strength increase after molding?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Some self-bonding LSR grades continue building adhesion during room-temperature storage or thermal post-curing. Testing time should therefore be defined in the inspection standard.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">How can silicone be kept away from threads or electrical contacts?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Precision mold shut-offs, masking fixtures, protective caps and controlled primer application can be used. These features should be considered during insert and mold design.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Johtop\u00e4\u00e4t\u00f6s<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Reliable LSR overmolding on metal inserts requires coordinated control of material chemistry, metal preparation, insert geometry, tooling and process conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The strongest design does not rely on only one factor. A robust component normally combines:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>A controlled metal surface<\/li>\n\n\n\n<li>A compatible primer or self-bonding LSR<\/li>\n\n\n\n<li>Mechanical retention where possible<\/li>\n\n\n\n<li>Rounded, low-stress bond edges<\/li>\n\n\n\n<li>Stable insert location<\/li>\n\n\n\n<li>Defined molding conditions<\/li>\n\n\n\n<li>Bond-strength and environmental testing<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Early DFM and material testing can prevent weak adhesion, cure inhibition, flash, insert movement and expensive tooling modifications.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For a custom LSR-overmolded metal component, provide the insert drawing, metal specification, operating environment and required bond test. These details allow the manufacturer to recommend a suitable LSR grade, surface-treatment method, insert design and validation plan.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>","protected":false},"excerpt":{"rendered":"<p>Liquid silicone rubber overmolding can combine a rigid metal insert with a flexible, heat-resistant and electrically insulating silicone layer in one finished component. The process is widely used for automotive connectors, medical instruments, electronic housings, vibration-damping parts, valves, handles and industrial sealing assemblies. However, successful LSR-to-metal overmolding depends on more than choosing a suitable silicone [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[1],"tags":[1427,2384,1857,2388,2386,2387,2382,2383,67,2385,2367],"class_list":["post-2667","post","type-post","status-publish","format-standard","hentry","category-industry-news","tag-custom-silicone-parts","tag-insert-design","tag-liquid-silicone-rubber-molding","tag-lsr-overmolding-on-metal-inserts","tag-lsr-primer","tag-metal-insert-molding","tag-self-bonding-lsr-2","tag-silicone-bond-strength","tag-silicone-overmolding","tag-silicone-surface-treatment","tag-silicone-to-metal-bonding"],"_links":{"self":[{"href":"https:\/\/www.fhysilicone.com\/fi\/wp-json\/wp\/v2\/posts\/2667","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.fhysilicone.com\/fi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.fhysilicone.com\/fi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.fhysilicone.com\/fi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fhysilicone.com\/fi\/wp-json\/wp\/v2\/comments?post=2667"}],"version-history":[{"count":1,"href":"https:\/\/www.fhysilicone.com\/fi\/wp-json\/wp\/v2\/posts\/2667\/revisions"}],"predecessor-version":[{"id":2669,"href":"https:\/\/www.fhysilicone.com\/fi\/wp-json\/wp\/v2\/posts\/2667\/revisions\/2669"}],"wp:attachment":[{"href":"https:\/\/www.fhysilicone.com\/fi\/wp-json\/wp\/v2\/media?parent=2667"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fhysilicone.com\/fi\/wp-json\/wp\/v2\/categories?post=2667"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fhysilicone.com\/fi\/wp-json\/wp\/v2\/tags?post=2667"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}