{"id":597,"date":"2013-11-05T10:20:39","date_gmt":"2013-11-05T09:20:39","guid":{"rendered":"http:\/\/blog.chci-pneumatiky.cz\/?p=133"},"modified":"2022-05-30T18:41:59","modified_gmt":"2022-05-30T18:41:59","slug":"starnuti-pneumatik-jak-poznat-nepouzitelnou-pneumatiku","status":"publish","type":"post","link":"https:\/\/pneuteka.cz\/mag\/starnuti-pneumatik-jak-poznat-nepouzitelnou-pneumatiku\/","title":{"rendered":"St\u00e1rnut\u00ed pneumatik &#8211; jak poznat nepou\u017eitelnou pneumatiku?"},"content":{"rendered":"<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-thumbnail wp-image-137\" alt=\"Popraskan\u00fd dez\u00e9n pneumatiky\" src=\"http:\/\/blog.chci-pneumatiky.cz\/wp-content\/uploads\/popraskany-dezen-150x150.jpg\" width=\"150\" height=\"150\" \/>O st\u00e1rnut\u00ed pneumatik se toho napsalo u\u017e mnoho, n\u00e1zory se mnohdy lis\u0161\u00ed. Ned\u00e1vno se z\u00e1stupci pr\u00e9miov\u00fdch zna\u010dek nechali sly\u0161et, \u017ee pneumatiky do 5 let od vyroben\u00ed se pova\u017euj\u00ed za nov\u00e9 a \u017e\u00e1dn\u00e9 vlastnosti neztr\u00e1cej\u00ed. Pan T\u0159etina z Bridgestone dokonce uv\u00e1d\u00ed: &#8220;R\u00e1di bychom ve\u0159ejnost ubezpe\u010dili, \u017ee v\u00fdrobce <strong>garantuje dobr\u00e9 vlastnosti pneumatiky a\u017e do st\u00e1\u0159\u00ed deseti let<\/strong>,&#8221; informuje. Nutno podotknout, \u017ee v\u017edy je to ale s podm\u00ednkou vhodn\u00e9ho skladov\u00e1n\u00ed a ide\u00e1ln\u00edch podm\u00ednek, kter\u00e9 se dop\u0159edu \u0161patn\u011b odhaduj\u00ed. Se\u010dteno a podtr\u017eeno, st\u00e1\u0159\u00ed pneumatik se sice d\u00e1 ur\u010dit podle <a href=\"http:\/\/wiki.chci-pneumatiky.cz\/dot_kod\">DOT k\u00f3du<\/a>, ale o <strong>faktick\u00e9m st\u00e1rnut\u00ed to v\u00edcem\u00e9n\u011b nic nevypov\u00edd\u00e1<\/strong>. Samoz\u0159ejm\u011b, pokud jsou sjet\u00e9 pod z\u00e1konnou mez, tak je t\u0159eba je vym\u011bnit. Ale jak jinak sledovat st\u00e1rnut\u00ed pneumatik?<!--more--><\/p>\n<p style=\"text-align: justify;\">Existuj\u00ed 3 hlavn\u00ed zp\u016fsoby st\u00e1rnut\u00ed pneumatik. Prvn\u00edm je to, \u017ee guma se st\u00e1v\u00e1 k\u0159eh\u010d\u00ed. Na spojov\u00e1n\u00ed molekul gumy b\u011bhem vulkanizace se pou\u017e\u00edv\u00e1 s\u00edra spolu s pou\u017eit\u00edm tepla a tlaku, co\u017e zaji\u0161\u0165uje pneumatice elasticitu a pevnost. Jak pneumatika absorbuje energii ve form\u011b sv\u011btla, tepla nebo pohybu tak pokra\u010duje ve vulkanizaci. St\u00e1le prob\u00edhaj\u00edc\u00ed vulkanizace zp\u016fsobuje \u017ee se guma st\u00e1v\u00e1 tu\u017e\u0161\u00ed a k\u0159eh\u010d\u00ed.<\/p>\n<p style=\"text-align: justify;\">Druh\u00fdm zp\u016fsobem st\u00e1rnut\u00ed pneumatik je oxidace zahrnuj\u00edc\u00ed kysl\u00edk a ozon ze vzduchu, kter\u00fd kompromituje s\u00edlu a pru\u017enost gumy a p\u0159ilnavost gumy k ocelov\u00fdm z\u00e1klad\u016fm pneumatiky. Prakticky teplo a kysl\u00edk zp\u016fsobuje p\u0159\u00ed\u010dnou vazbu mezi polymerov\u00fdmi \u0159et\u011bzci (pneumatika tak tvrdne) a rozd\u011blen\u00ed polymern\u00edch \u0159et\u011bzc\u016f (vedouc\u00ed k sn\u00ed\u017een\u00e9 elasticit\u011b).<\/p>\n<p style=\"text-align: justify;\">T\u0159et\u00edm zp\u016fsobem je rozkl\u00e1d\u00e1n\u00ed pneumatiky zp\u016fsoben\u00e9 vodou prostupuj\u00edc\u00ed pneumatikou a navazuj\u00edc\u00ed se na ocelov\u00e9 p\u00e1sy uvnit\u0159 pneumatiky. To zavin\u00ed, \u017ee vazba gumy na ocelov\u00fd z\u00e1klad pneumatiky se oslab\u00ed a bude m\u00e9n\u011b odolnou proti zah\u0159\u00edv\u00e1n\u00ed. Tento jev m\u016f\u017ee zp\u016fsobit i hu\u0161t\u011bn\u00ed pneumatik vzduchem, kter\u00fd nen\u00ed zcela such\u00fd. I nepou\u017eit\u00e9 pneumatiky budou k\u0159eh\u010d\u00ed, slab\u0161\u00ed a m\u00e9n\u011b elastick\u00e9, pokud jsou vystavov\u00e1ny vod\u011b, vzduchu, teplu a slune\u010dn\u00edmu svitu.<\/p>\n<h2 style=\"text-align: justify;\">Varovn\u00e9 znaky<\/h2>\n<p style=\"text-align: justify;\">Bez ohledu na v\u011bk pneumatik je nutn\u00e9 je vym\u011bnit, pokud vykazuj\u00ed znaky st\u00e1rnut\u00ed. <strong>Takov\u00fdmi znaky jsou praskliny ve vzorku pneumatik nebo na bo\u010dnici nebo tak\u00e9 vypukliny, op\u011bt na vzorku nebo na bo\u010dnici<\/strong> &#8211; oboj\u00ed naleznete na obr\u00e1zc\u00edch. Ka\u017ed\u00e1 pneumatika by m\u011bla b\u00fdt pravideln\u011b kontrolov\u00e1na a v p\u0159\u00edpad\u011b pot\u0159eby vym\u011bn\u011bna, i v\u010detn\u011b rezervy.<\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/blog.chci-pneumatiky.cz\/wp-content\/uploads\/popraskana-bocnice.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-136\" alt=\"Popraskan\u00e1 bo\u010dnice pneumatiky\" src=\"http:\/\/blog.chci-pneumatiky.cz\/wp-content\/uploads\/popraskana-bocnice.jpg\" width=\"562\" height=\"383\" \/><\/a> <a href=\"http:\/\/blog.chci-pneumatiky.cz\/wp-content\/uploads\/popraskany-dezen.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-137\" alt=\"Popraskan\u00fd dez\u00e9n pneumatiky\" src=\"http:\/\/blog.chci-pneumatiky.cz\/wp-content\/uploads\/popraskany-dezen.jpg\" width=\"545\" height=\"369\" \/><\/a><\/p>\n<p style=\"text-align: justify;\">\n","protected":false},"excerpt":{"rendered":"<p>O st\u00e1rnut\u00ed pneumatik se toho napsalo u\u017e mnoho, n\u00e1zory se mnohdy lis\u0161\u00ed. Ned\u00e1vno se z\u00e1stupci pr\u00e9miov\u00fdch zna\u010dek nechali sly\u0161et, \u017ee pneumatiky do 5 let od vyroben\u00ed se pova\u017euj\u00ed za nov\u00e9 a \u017e\u00e1dn\u00e9 vlastnosti neztr\u00e1cej\u00ed. Pan T\u0159etina z Bridgestone dokonce uv\u00e1d\u00ed: &#8220;R\u00e1di bychom ve\u0159ejnost ubezpe\u010dili, \u017ee v\u00fdrobce garantuje dobr\u00e9 vlastnosti pneumatiky a\u017e do st\u00e1\u0159\u00ed deseti let,&#8221; [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":137,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[32],"tags":[],"class_list":["post-597","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-pneucyklopedie"],"acf":[],"_links":{"self":[{"href":"https:\/\/pneuteka.cz\/mag\/wp-json\/wp\/v2\/posts\/597","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pneuteka.cz\/mag\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pneuteka.cz\/mag\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pneuteka.cz\/mag\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/pneuteka.cz\/mag\/wp-json\/wp\/v2\/comments?post=597"}],"version-history":[{"count":1,"href":"https:\/\/pneuteka.cz\/mag\/wp-json\/wp\/v2\/posts\/597\/revisions"}],"predecessor-version":[{"id":802,"href":"https:\/\/pneuteka.cz\/mag\/wp-json\/wp\/v2\/posts\/597\/revisions\/802"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pneuteka.cz\/mag\/wp-json\/wp\/v2\/posts\/137"}],"wp:attachment":[{"href":"https:\/\/pneuteka.cz\/mag\/wp-json\/wp\/v2\/media?parent=597"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pneuteka.cz\/mag\/wp-json\/wp\/v2\/categories?post=597"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pneuteka.cz\/mag\/wp-json\/wp\/v2\/tags?post=597"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}