{"id":699,"date":"2017-09-23T23:16:37","date_gmt":"2017-09-23T23:16:37","guid":{"rendered":"http:\/\/80.85.86.254\/sjor\/?p=699"},"modified":"2024-10-15T15:55:20","modified_gmt":"2024-10-15T15:55:20","slug":"4-2-plastframleidsla","status":"publish","type":"post","link":"https:\/\/himinnoghaf.is\/mengunsjavar\/index.php\/2017\/09\/23\/4-2-plastframleidsla\/","title":{"rendered":"4.2 Plastframlei\u00f0sla"},"content":{"rendered":"

Upp \u00far 1950 var fari\u00f0 a\u00f0 framlei\u00f0a plast \u00ed miklu magni og nota \u00fea\u00f0 \u00ed alls kyns umb\u00fa\u00f0ir og a\u00f0rar v\u00f6rur. Fr\u00e1 \u00feessum t\u00edma hefur framlei\u00f0sla plasts aukist \u00e1r fr\u00e1 \u00e1ri (sj\u00e1 mynd 4.3).<\/p>\n

<\/div>\n

Plast er t.d. nota\u00f0 \u00ed einnota og fj\u00f6lnota bor\u00f0b\u00fana\u00f0, umb\u00fa\u00f0ir, bur\u00f0arpoka, leikf\u00f6ng, fatna\u00f0, b\u00fas\u00e1h\u00f6ld, vei\u00f0arf\u00e6ri, h\u00fasg\u00f6gn, l\u00e6kningav\u00f6rur og \u00fear fram eftir g\u00f6tunum. Plast er til margra hluta nytsamlegt og \u00fe\u00e6gilegt \u00ed notkun. V\u00f6rur \u00far plasti eru yfirleitt endingarg\u00f3\u00f0ar og oft frekar \u00f3d\u00fdrar. Tilkoma plastsins var \u00fev\u00ed til mikilla \u00fe\u00e6ginda fyrir margt f\u00f3lk.<\/p>\n

\"\"<\/a>

Mynd 4.4. Gamlar augl\u00fdsingar fyrir plast. Einnota plast au\u00f0veldar heimilisst\u00f6rfin og var jafnvel s\u00e9rstaklega reynt a\u00f0 h\u00f6f\u00f0a til h\u00fasm\u00e6\u00f0ra me\u00f0 \u00fev\u00ed a\u00f0 hafa sm\u00e1b\u00f6rn \u00e1 myndunum.<\/p><\/div>\n

Plast er framleitt \u00far ol\u00edu og eru um 5-10% af unninni ol\u00edu \u00ed heiminum notu\u00f0 til a\u00f0 framlei\u00f0a plastefni. \u00cd ol\u00eduhreinsist\u00f6\u00f0<\/a> eru mismunandi afur\u00f0ir unnar \u00far hr\u00e1ol\u00edu. Ein af \u00feessum afur\u00f0um er nafta, sem er mikilv\u00e6gasta hr\u00e1efni\u00f0 \u00ed plastframlei\u00f0slu. \u00cd ol\u00eduefnaverksmi\u00f0ju eru fyrst b\u00fanar til \u00far nafta svonefndar einli\u00f0ur (e. monomer) og svo \u00far \u00feeim svo fj\u00f6lli\u00f0ur (e. polymer). Einli\u00f0ur eru frekar litlar sameindir sem geta bundist \u00f6\u00f0rum sams konar sameindum og mynda\u00f0 mj\u00f6g langar ke\u00f0jur sem nefnast \u00fe\u00e1 fj\u00f6lli\u00f0ur. \u00c1 mynd 4.6 s\u00e9st hvernig p\u00f3l\u00fdst\u00fdren, sem oft er nota\u00f0 \u00ed umb\u00fa\u00f0ir utan um matv\u00e6li (\u00fe.\u00e1 m. frau\u00f0plast), er mynda\u00f0 \u00far m\u00f6rgum st\u00fdren-sameindum. A\u00f0rar algengar plastfj\u00f6lli\u00f0ur eru t.d. p\u00f3l\u00fdet\u00fdlen (PE-plast), p\u00f3l\u00fdpr\u00f3l\u00fdlen (PP-plast) og p\u00f3l\u00fdv\u00edn\u00fdlk\u00f3r\u00ed\u00f0 (PVC-plast), sem ger\u00f0ar \u00far et\u00fdlen-sameindum, pr\u00f3p\u00fdlen-sameindum og v\u00edn\u00fdlkl\u00f3r\u00ed\u00f0-sameindum. Forskeyti\u00f0 \u201ep\u00f3l\u00fd-\u201c \u00fe\u00fd\u00f0ir \u201efj\u00f6l-\u201c og v\u00edsar til \u00feess a\u00f0 hver ke\u00f0ja er samsett \u00far m\u00f6rgum sameindum. Hver fj\u00f6lli\u00f0a hefur s\u00edna eiginleika, byggingu og st\u00e6r\u00f0 eftir \u00fev\u00ed \u00far hva\u00f0a einli\u00f0um h\u00fan er samsett. Fj\u00f6lli\u00f0urnar koma oftast \u00fat \u00far framlei\u00f0sluferlinu sem litlar perlur (sj\u00e1 mynd 4.6) en stundum l\u00edka sem duft, deig e\u00f0a v\u00f6kvi.<\/p>\n

\"\"<\/a>

Mynd 4.5. Plastframlei\u00f0sla. Plast er framleitt \u00far ol\u00eduv\u00f6rum.<\/p><\/div>\n

Fj\u00f6lli\u00f0urnar \u00far ol\u00eduefnaverksmi\u00f0junum, hvort sem \u00fe\u00e6r l\u00edta \u00fat eins og perlur e\u00f0a eitthva\u00f0 anna\u00f0, eru \u00feessu n\u00e6st fluttar \u00ed verksmi\u00f0jur \u00fear sem \u00fe\u00e6r eru br\u00e6ddar, \u00edbl\u00f6ndunarefnum b\u00e6tt vi\u00f0 og plasti\u00f0 m\u00f3ta\u00f0 \u00ed vi\u00f0eigandi form. Til \u00feess a\u00f0 n\u00e1 fram \u00feeim eiginleikum sem s\u00f3st er eftir hverju sinni er \u00fdmsum efnum blanda\u00f0 \u00ed plasti\u00f0, s.s. m\u00fdkingarefnum, hersluefnum<\/span>, litarefnum og andoxunarefnum<\/span>. Sum \u00feessara efna eru h\u00e6ttuleg heilsu okkar. \u00deetta eru t.d. efni \u00e1 bor\u00f0 vi\u00f0 \u00feal\u00f6t og BPA<\/span>, sem sett er \u00ed \u00fdmsar plastv\u00f6rur til a\u00f0 gera plasti\u00f0 m\u00fdkra og m\u00f3tanlegra.<\/p>\n

\"\"<\/a>

Mynd 4.6. V\u00f6r\u00f0ur \u00ed framlei\u00f0sluferli plasts: (Til vinstri) P\u00f3l\u00fdst\u00fdren er b\u00fai\u00f0 til me\u00f0 fj\u00f6lli\u00f0un \u00e1 einli\u00f0unni st\u00fdren. (Til h\u00e6gri) Plastperlur tilb\u00fanar til frekari m\u00f3tunar \u00ed vi\u00f0eigandi form.<\/p><\/div>\n

Sumar plastv\u00f6rur, svo sem plastpokar og einnota plastbor\u00f0b\u00fana\u00f0ur, eru bara nota\u00f0ar \u00ed nokkrar m\u00edn\u00fatur \u00e1\u00f0ur en \u00feeim er hent \u00ed rusli\u00f0. A\u00f0rar v\u00f6rur eru \u00fe\u00f3 ger\u00f0ar til notkunar \u00ed lengri t\u00edma (t.d. h\u00fasg\u00f6gn, fatna\u00f0ur og margnota plastbor\u00f0b\u00fana\u00f0ur).<\/p>\n

Plasti\u00f0 sem vi\u00f0 sj\u00e1um mest af \u00ed daglegu l\u00edfi er au\u00f0kennt me\u00f0 n\u00famerum, sem er m.a. \u00e6tla\u00f0 a\u00f0 au\u00f0velda endurvinnslu, \u00fev\u00ed a\u00f0 mismunandi ger\u00f0ir af plasti \u00feurfa mismunandi me\u00f0h\u00f6ndlun. N\u00famerin eru t\u00f6lur fr\u00e1 einum upp \u00ed sj\u00f6 innan \u00ed \u00fear til ger\u00f0um \u00fer\u00edhyrningum sem prenta\u00f0ir eru \u00e1 plasti\u00f0 \u2013 og eru miss\u00fdnilegir eftir \u00fev\u00ed hversu g\u00f3\u00f0 sj\u00f3nin er. \"\"<\/p>\n","protected":false},"excerpt":{"rendered":"

Upp \u00far 1950 var fari\u00f0 a\u00f0 framlei\u00f0a plast \u00ed miklu magni og nota \u00fea\u00f0 \u00ed alls kyns umb\u00fa\u00f0ir og a\u00f0rar v\u00f6rur. Fr\u00e1 \u00feessum t\u00edma hefur framlei\u00f0sla plasts aukist \u00e1r fr\u00e1 \u00e1ri (sj\u00e1 mynd 4.3). Plast er t.d. nota\u00f0 \u00ed einnota Lesa meira…<\/a><\/p>\n","protected":false},"author":2,"featured_media":1008,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[],"class_list":["post-699","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-4-urgangur-plast"],"_links":{"self":[{"href":"https:\/\/himinnoghaf.is\/mengunsjavar\/index.php\/wp-json\/wp\/v2\/posts\/699","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/himinnoghaf.is\/mengunsjavar\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/himinnoghaf.is\/mengunsjavar\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/himinnoghaf.is\/mengunsjavar\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/himinnoghaf.is\/mengunsjavar\/index.php\/wp-json\/wp\/v2\/comments?post=699"}],"version-history":[{"count":40,"href":"https:\/\/himinnoghaf.is\/mengunsjavar\/index.php\/wp-json\/wp\/v2\/posts\/699\/revisions"}],"predecessor-version":[{"id":3959,"href":"https:\/\/himinnoghaf.is\/mengunsjavar\/index.php\/wp-json\/wp\/v2\/posts\/699\/revisions\/3959"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/himinnoghaf.is\/mengunsjavar\/index.php\/wp-json\/wp\/v2\/media\/1008"}],"wp:attachment":[{"href":"https:\/\/himinnoghaf.is\/mengunsjavar\/index.php\/wp-json\/wp\/v2\/media?parent=699"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/himinnoghaf.is\/mengunsjavar\/index.php\/wp-json\/wp\/v2\/categories?post=699"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/himinnoghaf.is\/mengunsjavar\/index.php\/wp-json\/wp\/v2\/tags?post=699"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}