{"id":10305,"date":"2026-04-22T16:23:36","date_gmt":"2026-04-22T08:23:36","guid":{"rendered":"https:\/\/www.packqc.com\/?post_type=standard&#038;p=10305"},"modified":"2026-04-22T16:23:37","modified_gmt":"2026-04-22T08:23:37","slug":"astm-d2732","status":"publish","type":"standard","link":"https:\/\/www.packqc.com\/hr\/standard\/astm-d2732\/","title":{"rendered":"ASTM D2732"},"content":{"rendered":"<h2 class=\"wp-block-heading\">\u0160to je ASTM D2732 i za\u0161to je to va\u017eno<\/h2>\n\n\n\n<p><strong>ASTM D2732<\/strong> Definira standardizirani pristup za procjenu <strong>neograni\u010deno linearno termi\u010dko skupljanje<\/strong> od plasti\u010dne folije i listova (debljine \u2264 0,76 mm). U prakti\u010dnom smislu, ova metoda kvantificira koliko se folija skuplja kada je izlo\u017eena povi\u0161enim temperaturama. <strong>bez vanjskih ograni\u010denja<\/strong>.<\/p>\n\n\n\n<p>Tijekom proizvodnje filma \u2014 kao \u0161to su ekstruzija ili orijentacija \u2014<strong>U materijalnu strukturu uvode se unutarnji naponi.<\/strong>. Kada se primijeni toplina, ovi naponi se opu\u0161taju, \u0161to dovodi do dimenzionalnog skupljanja. Razumijevanje ovog pona\u0161anja je klju\u010dno za:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Cjelovitost pakiranja<\/strong> (npr. termo-skupljaju\u0107e folije, etikete)<\/li>\n\n\n\n<li><strong>Zaptivanje u medicinskom pakiranju<\/strong><\/li>\n\n\n\n<li><strong>Dimenzionalna stabilnost u industrijskim filmovima<\/strong><\/li>\n<\/ul>\n\n\n\n<p><strong>ASTM D2732 pru\u017ea ponovljiv okvir<\/strong> za mjerenje skupljanja pri razli\u010ditim temperaturama, omogu\u0107uju\u0107i in\u017eenjerima i timovima za kontrolu kvalitete da pove\u017eu performanse s uvjetima obrade.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Metoda ispitivanja toplinskog skupljanja<\/h2>\n\n\n\n<p>The <strong>Metoda ispitivanja toplinskog skupljanja<\/strong> Opisana u ASTM D2732 usredoto\u010duje se na kontroliranu toplinsku izlo\u017eenost u okru\u017eenju teku\u0107e kupke.<\/p>\n\n\n\n<p>Klju\u010dni tehni\u010dki principi uklju\u010duju:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Neograni\u010deno stanje:<\/strong> Uzorak se mora slobodno smanjivati bez mehani\u010dkog ometanja.<\/li>\n\n\n\n<li><strong>Termalna ravnote\u017ea:<\/strong> Uzorak mora dosegnuti stabilnu temperaturu kako bi se postiglo maksimalno skupljanje.<\/li>\n\n\n\n<li><strong>Dvosmjerno mjerenje:<\/strong> Skupanje se procjenjuje u oba <strong>smjer stroja (MD)<\/strong> i <strong>popre\u010dni smjer (TD)<\/strong>.<\/li>\n<\/ul>\n\n\n\n<p><strong>Kriti\u010dki uvid:<\/strong> Skupljanje nije konstantno\u2014zna\u010dajno varira s temperaturom. Stoga testiranje na vi\u0161e temperaturnih to\u010daka pru\u017ea <strong>profil skupljanja<\/strong>, a ne samo jedna vrijednost.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Postupak ispitivanja skupljanja<\/h2>\n\n\n\n<p>Standardizirani <strong>postupak ispitivanja skupljanja<\/strong> osigurava to\u010dnost i reproducibilnost:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Priprema uzoraka<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Rezati <strong>Uzorci 100 mm \u00d7 100 mm<\/strong><\/li>\n\n\n\n<li>Koristite barem <strong>dva uzorka po temperaturi ispitivanja<\/strong><\/li>\n\n\n\n<li>Ozna\u010dite smjer rada stroja ako je potrebno<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Izvr\u0161enje testa<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li>Postavite uzorak u <strong>Besplatni dr\u017ea\u010d za sklopive stolice<\/strong> izbje\u0107i ograni\u010denje<\/li>\n\n\n\n<li>Zabilje\u017eite temperaturu kade prije uranjanja<\/li>\n\n\n\n<li>Umo\u010dite uzorak za <strong>~10 sekundi<\/strong> (ili dok se ne postigne ravnote\u017ea)<\/li>\n\n\n\n<li>Odmah prenesite u sredstvo za hla\u0111enje.<\/li>\n\n\n\n<li>Izmjerite kona\u010dne dimenzije nakon stabilizacije.<\/li>\n<\/ol>\n\n\n\n<p><strong>Va\u017ene mjere opreza:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Izbjegavajte prethodno zagrijavanje uzorka prije uranjanja.<\/li>\n\n\n\n<li>Sprije\u010dite istezanje uzorka tijekom rukovanja<\/li>\n\n\n\n<li>Osigurajte ravnomjernu raspodjelu temperature u kadi.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Prora\u010dun skupljanja<\/h3>\n\n\n\n<p><math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><semantics><mrow><mi>S<\/mi><mi>h<\/mi><mi>r<\/mi><mi>i<\/mi><mi>n<\/mi><mi>k<\/mi><mi>a<\/mi><mi>g<\/mi><mi>e<\/mi><mo stretchy=\"false\">(<\/mo><mi mathvariant=\"normal\">%<\/mi><mo stretchy=\"false\">)<\/mo><mo>=<\/mo><mfrac><mrow><msub><mi>L<\/mi><mn>0<\/mn><\/msub><mo>\u2212<\/mo><msub><mi>L<\/mi><mi>f<\/mi><\/msub><\/mrow><msub><mi>L<\/mi><mn>0<\/mn><\/msub><\/mfrac><mo>\u00d7<\/mo><mn>100<\/mn><\/mrow><annotation encoding=\"application\/x-tex\">Skr\u010denje(\\%) = \\frac{L_0 \u2013 L_f}{L_0} \\times 100<\/annotation><\/semantics><\/math>Skupanje(%)=L0\u200bL0\u200b\u2212Lf\u200b\u200b\u00d7100<\/p>\n\n\n\n<p>Gdje:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><semantics><mrow><msub><mi>L<\/mi><mn>0<\/mn><\/msub><\/mrow><annotation encoding=\"application\/x-tex\">L_0<\/annotation><\/semantics><\/math>L0: Po\u010detna duljina (obi\u010dno 100 mm)<\/li>\n\n\n\n<li><math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><semantics><mrow><msub><mi>L<\/mi><mi>f<\/mi><\/msub><\/mrow><annotation encoding=\"application\/x-tex\">L_f<\/annotation><\/semantics><\/math>Lf: Kona\u010dna duljina nakon skupljanja<\/li>\n<\/ul>\n\n\n\n<p>Ova formula pru\u017ea <strong>postotak linearnog skupljanja<\/strong>, klju\u010dni parametar za usporedbu materijala i kontrolu kvalitete.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Film Free Shrink Tester: Pobolj\u0161anje to\u010dnosti ispitivanja<\/h2>\n\n\n\n<p>A <strong><a href=\"https:\/\/www.packqc.com\/hr\/products\/fst-01-film-shrinkage-tester\/\" target=\"_blank\" data-type=\"products\" data-id=\"9536\" rel=\"noreferrer noopener\">film free shrink tester<\/a><\/strong> je klju\u010dno za izvo\u0111enje ASTM D2732 s visokom precizno\u0161\u0107u. U usporedbi s ru\u010dnim postavkama, namjenski instrumenti nude:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Stabilna kontrola temperature (\u00b10,3 \u00b0C)<\/strong><\/li>\n\n\n\n<li><strong>Jednoliko grijanje teku\u0107im medijem<\/strong><\/li>\n\n\n\n<li><strong>Kontrolirano vrijeme uranjanja<\/strong><\/li>\n\n\n\n<li><strong>Dosljedni neograni\u010deni uvjeti<\/strong><\/li>\n<\/ul>\n\n\n\n<p>Na primjer, <strong>Stani\u010dni instrumenti <a href=\"https:\/\/www.packqc.com\/hr\/products\/fst-01-film-shrinkage-tester\/\" target=\"_blank\" rel=\"noreferrer noopener\">FST-01 tester za skupljanje bez filmskog sloja<\/a><\/strong> omogu\u0107uje laboratorijima da:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Simulirajte uvjete skupljanja u stvarnom svijetu<\/li>\n\n\n\n<li>Generirajte ponovljive podatke o skupljanju<\/li>\n\n\n\n<li>Smanjite varijabilnost uzrokovanu operaterom<\/li>\n<\/ul>\n\n\n\n<p>Njegov <strong>Sustav grijanja s PID-regulacijom i standardizirane armature<\/strong> osigurati uskla\u0111enost s normom ASTM D2732 uz pobolj\u0161anje operativne u\u010dinkovitosti.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Klju\u010dni \u010dimbenici koji utje\u010du na rezultate ispitivanja ASTM D2732<\/h2>\n\n\n\n<p>Da biste ispravno protuma\u010dili rezultate, uzmite u obzir sljede\u0107e varijable:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1. Sastav materijala<\/h3>\n\n\n\n<p>Razli\u010diti polimeri (PET, PVC, PE) pokazuju razli\u010dito pona\u0161anje pri skupljanju zbog molekularne orijentacije i kristalnosti.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">2. Povijest obrade<\/h3>\n\n\n\n<p>Omjeri rastezanja filma, brzine hla\u0111enja i odmaranje izravno utje\u010du <strong>razine preostalog naprezanja<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">3. Odabir temperature<\/h3>\n\n\n\n<p>Testiranje pri vi\u0161e temperatura otkriva:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Po\u010detak skupljanja<\/li>\n\n\n\n<li>Maksimalna to\u010dka skupljanja<\/li>\n\n\n\n<li>Pona\u0161anje pri toplinskoj tranziciji<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">4. Debljina i struktura<\/h3>\n\n\n\n<p>Deblji ili vi\u0161eslojni filmovi mogu zahtijevati du\u017ee vrijeme uranjanja da bi se postigla ravnote\u017ea.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">FAQ<\/h2>\n\n\n\n<p>1. Koji su materijali prikladni za ispitivanje prema normi ASTM D2732?<br>Plasti\u010dne folije i listovi debljine \u22640,76 mm, uklju\u010duju\u0107i PET, PE, PVC i vi\u0161eslojne laminate.<\/p>\n\n\n\n<p>2. Za\u0161to je nekontrolirano smanjenje va\u017eno?<br>Odra\u017eava unutarnje materijalno pona\u0161anje bez vanjskih sila, pru\u017eaju\u0107i <strong>istinske karakteristike skupljanja<\/strong>.<\/p>\n\n\n\n<p>3. Koliko dugo treba uroniti uzorke?<br>Obi\u010dno 10 sekundi, ali deblji ili novi materijali mogu zahtijevati provjeru kako bi se osiguralo potpuno skupljanje.<\/p>\n\n\n\n<p>4. Koja je razlika izme\u0111u MD i TD smanjenja?<br>MD (smjer stroja) se podudara sa smjerom proizvodnje filma, dok je TD okomit\u2014oboje utje\u010du na performanse na razli\u010dite na\u010dine.<\/p>\n\n\n\n<p>5. Mo\u017ee <a href=\"https:\/\/store.astm.org\/d2732-14r25.html\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">ASTM D2732<\/a> mo\u017ee li se koristiti za skupljanje na bazi otapala?<br>Ne, to ne uzima u obzir skupljanje uzrokovano gubitkom otapala.<\/p>\n\n\n\n<p><\/p>","protected":false},"excerpt":{"rendered":"<p>ASTM D2732 procjenjuje slobodno linearno toplinsko skupljanje plasti\u010dnih folija mjerenjem promjena dimenzija nakon kontroliranog zagrijavanja.<\/p>","protected":false},"featured_media":10306,"parent":0,"template":"","meta":{"_acf_changed":true,"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":"disabled","footer-sml-layout":"","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":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","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-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-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-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-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-gradient":""}}},"standard-category":[],"class_list":["post-10305","standard","type-standard","status-publish","has-post-thumbnail","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.packqc.com\/hr\/wp-json\/wp\/v2\/standard\/10305","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.packqc.com\/hr\/wp-json\/wp\/v2\/standard"}],"about":[{"href":"https:\/\/www.packqc.com\/hr\/wp-json\/wp\/v2\/types\/standard"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.packqc.com\/hr\/wp-json\/wp\/v2\/media\/10306"}],"wp:attachment":[{"href":"https:\/\/www.packqc.com\/hr\/wp-json\/wp\/v2\/media?parent=10305"}],"wp:term":[{"taxonomy":"standard-category","embeddable":true,"href":"https:\/\/www.packqc.com\/hr\/wp-json\/wp\/v2\/standard-category?post=10305"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}