{"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\/lt\/standard\/astm-d2732\/","title":{"rendered":"ASTM D2732"},"content":{"rendered":"<h2 class=\"wp-block-heading\">Kas yra ASTM D2732 ir kod\u0117l jis svarbus<\/h2>\n\n\n\n<p><strong>ASTM D2732<\/strong> apibr\u0117\u017eia standartizuot\u0105 metod\u0105, skirt\u0105 \u012fvertinti <strong>nesuvar\u017eytas linijinis terminis susitraukimas<\/strong> plastikin\u0117s pl\u0117vel\u0117s ir lak\u0161t\u0173 (\u22640,76 mm storio). Prakti\u0161kai \u0161iuo metodu nustatoma, kiek pl\u0117vel\u0117 susitraukia veikiama padidintos temperat\u016bros. <strong>be i\u0161orini\u0173 apribojim\u0173<\/strong>.<\/p>\n\n\n\n<p>Gaminant pl\u0117vel\u0119, pavyzd\u017eiui, ekstruzijos ar orientavimo metu.<strong>med\u017eiagos strukt\u016broje atsiranda vidiniai \u012ftempiai.<\/strong>. Veikiant kar\u0161\u010diui, \u0161ie \u012ftempiai atsipalaiduoja, tod\u0117l atsiranda matmen\u0173 susitraukimas. Suprasti \u0161i\u0105 elgsen\u0105 labai svarbu:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Pakuot\u0117s vientisumas<\/strong> (pvz., susitraukian\u010dios pl\u0117vel\u0117s, etiket\u0117s).<\/li>\n\n\n\n<li><strong>Medicinini\u0173 pakuo\u010di\u0173 sandarumas<\/strong><\/li>\n\n\n\n<li><strong>Pramonini\u0173 pl\u0117veli\u0173 matmen\u0173 stabilumas<\/strong><\/li>\n<\/ul>\n\n\n\n<p><strong>ASTM D2732 pateikia pakartojam\u0105 sistem\u0105<\/strong> matuoti susitraukim\u0105 skirtingose temperat\u016brose, kad in\u017einieriai ir kokyb\u0117s kontrol\u0117s komandos gal\u0117t\u0173 susieti na\u0161um\u0105 su apdorojimo s\u0105lygomis.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u0160iluminio susitraukimo bandymo metodas<\/h2>\n\n\n\n<p>The <strong>terminio susitraukimo bandymo metodas<\/strong> apra\u0161ytas ASTM D2732, daugiausia d\u0117mesio skiriama kontroliuojamam terminiam poveikiui skys\u010dio vonioje.<\/p>\n\n\n\n<p>Pagrindiniai techniniai principai:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Nesuvar\u017eyta b\u016bkl\u0117:<\/strong> Bandinys turi laisvai trauktis be mechanini\u0173 trukd\u017ei\u0173.<\/li>\n\n\n\n<li><strong>\u0160ilumin\u0117 pusiausvyra:<\/strong> Bandinys turi pasiekti stabili\u0105 temperat\u016br\u0105, kad susitraukt\u0173 maksimaliai.<\/li>\n\n\n\n<li><strong>Dvipusis matavimas:<\/strong> Susitraukimas vertinamas tiek <strong>ma\u0161inos kryptis (MD)<\/strong> ir <strong>skersine kryptimi (TD)<\/strong>.<\/li>\n<\/ul>\n\n\n\n<p><strong>Kritin\u0117 \u012f\u017evalga:<\/strong> Susitraukimas n\u0117ra pastovus - jis labai kinta priklausomai nuo temperat\u016bros. Tod\u0117l bandymai keliuose temperat\u016bros ta\u0161kuose suteikia <strong>susitraukimo profilis<\/strong>, o ne tik vien\u0105 reik\u0161m\u0119.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Susitraukimo bandymo proced\u016bra<\/h2>\n\n\n\n<p>Standartizuotas <strong>susitraukimo bandymo proced\u016bra<\/strong> u\u017etikrina tikslum\u0105 ir atkuriamum\u0105:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Bandini\u0173 paruo\u0161imas<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>I\u0161kirpti <strong>100 mm \u00d7 100 mm m\u0117giniai<\/strong><\/li>\n\n\n\n<li>Naudokite bent <strong>du bandiniai vienai bandymo temperat\u016brai<\/strong><\/li>\n\n\n\n<li>Jei reikia, pa\u017eym\u0117kite ma\u0161inos krypt\u012f<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Testo vykdymas<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u012ed\u0117kite m\u0117gin\u012f \u012f <strong>nemokamas susitraukimo laikiklis<\/strong> i\u0161vengti apribojim\u0173<\/li>\n\n\n\n<li>\u012era\u0161ykite vonios temperat\u016br\u0105 prie\u0161 panardinim\u0105<\/li>\n\n\n\n<li>Panardinkite m\u0117gin\u012f <strong>~10 sekund\u017ei\u0173<\/strong> (arba iki pusiausvyros)<\/li>\n\n\n\n<li>Nedelsiant perkelkite \u012f \u0161aldymo terp\u0119<\/li>\n\n\n\n<li>I\u0161matuokite galutinius matmenis po stabilizavimo<\/li>\n<\/ol>\n\n\n\n<p><strong>Svarbios atsargumo priemon\u0117s:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Prie\u0161 panardinant m\u0117gin\u012f venkite j\u012f i\u0161 anksto pa\u0161ildyti.<\/li>\n\n\n\n<li>U\u017ekirskite keli\u0105 m\u0117ginio i\u0161tempimui j\u012f tvarkant<\/li>\n\n\n\n<li>U\u017etikrinti tolyg\u0173 vonios temperat\u016bros pasiskirstym\u0105<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Susitraukimo apskai\u010diavimas<\/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\">Susitraukimas(\\%) = \\frac{L_0 - L_f}{L_0} \\ kart\u0173 100<\/annotation><\/semantics><\/math>Susitraukimas(%)=L0L0-Lf\u00d7100<\/p>\n\n\n\n<p>Kur:<\/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: Pradinis ilgis (paprastai 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: Galutinis ilgis po susitraukimo<\/li>\n<\/ul>\n\n\n\n<p>Pagal \u0161i\u0105 formul\u0119 <strong>linijinio susitraukimo procentin\u0117 dalis<\/strong>, tai pagrindinis med\u017eiag\u0173 palyginimo ir kokyb\u0117s kontrol\u0117s parametras.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Pl\u0117vel\u0117s be pl\u0117vel\u0117s susitraukimo testeris: Bandym\u0173 tikslumo didinimas<\/h2>\n\n\n\n<p>A <strong><a href=\"https:\/\/www.packqc.com\/lt\/products\/fst-01-film-shrinkage-tester\/\" target=\"_blank\" data-type=\"products\" data-id=\"9536\" rel=\"noreferrer noopener\">pl\u0117vel\u0117s be pl\u0117vel\u0117s susitraukimo testeris<\/a><\/strong> labai svarbu, kad ASTM D2732 standartas b\u016bt\u0173 vykdomas labai tiksliai. Palyginti su rankiniu b\u016bdu atliekamais nustatymais, special\u016bs prietaisai si\u016blo:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Stabilus temperat\u016bros valdymas (\u00b10,3 \u00b0C)<\/strong><\/li>\n\n\n\n<li><strong>Tolygus kaitinimas per skyst\u0105 terp\u0119<\/strong><\/li>\n\n\n\n<li><strong>Kontroliuojamas panardinimo laikas<\/strong><\/li>\n\n\n\n<li><strong>Nuolatin\u0117s nevar\u017eomos s\u0105lygos<\/strong><\/li>\n<\/ul>\n\n\n\n<p>Pavyzd\u017eiui. <strong>L\u0105steli\u0173 instrumentai <a href=\"https:\/\/www.packqc.com\/lt\/products\/fst-01-film-shrinkage-tester\/\" target=\"_blank\" rel=\"noreferrer noopener\">FST-01 Pl\u0117vel\u0117s nesusitraukimo testeris<\/a><\/strong> leid\u017eia laboratorijoms:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Imituokite realaus pasaulio susitraukimo s\u0105lygas<\/li>\n\n\n\n<li>Generuoti pakartojamus susitraukimo duomenis<\/li>\n\n\n\n<li>Suma\u017einti operatoriaus nulemt\u0105 kintamum\u0105<\/li>\n<\/ul>\n\n\n\n<p>Jos <strong>PID valdoma \u0161ildymo sistema ir standartizuoti \u012frenginiai<\/strong> u\u017etikrinti atitikt\u012f ASTM D2732 standartui ir kartu padidinti veiklos efektyvum\u0105.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Pagrindiniai veiksniai, turintys \u012ftakos ASTM D2732 rezultatams<\/h2>\n\n\n\n<p>Nor\u0117dami teisingai interpretuoti rezultatus, atsi\u017evelkite \u012f \u0161iuos kintamuosius:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">1. Med\u017eiagos sud\u0117tis<\/h3>\n\n\n\n<p>Skirtingi polimerai (PET, PVC, PE) pasi\u017eymi skirtingomis susitraukimo savyb\u0117mis, kurias lemia molekulin\u0117 orientacija ir kristalingumas.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">2. Apdorojimo istorija<\/h3>\n\n\n\n<p>Pl\u0117vel\u0117s i\u0161tempimo santykis, au\u0161inimo greitis ir atkaitinimas turi tiesiogin\u0117s \u012ftakos <strong>liekamojo \u012ftempio lygiai<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">3. \u0924\u093e\u092a Temperat\u016bros parinkimas<\/h3>\n\n\n\n<p>Atlikus bandymus \u012fvairiose temperat\u016brose nustatyta:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Susitraukimo prad\u017eia<\/li>\n\n\n\n<li>Did\u017eiausias susitraukimo ta\u0161kas<\/li>\n\n\n\n<li>\u0160iluminio per\u0117jimo elgsena<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">4. Storis ir strukt\u016bra<\/h3>\n\n\n\n<p>Storesn\u0117ms arba daugiasluoksn\u0117ms pl\u0117vel\u0117ms gali prireikti ilgesnio panardinimo laiko, kad b\u016bt\u0173 pasiekta pusiausvyra.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">DUK<\/h2>\n\n\n\n<p>1. Kokios med\u017eiagos tinka ASTM D2732 bandymams?<br>Plastikin\u0117s pl\u0117vel\u0117s ir lak\u0161tai, kuri\u0173 storis \u22640,76 mm, \u012fskaitant PET, PE, PVC ir daugiasluoksnius laminatus.<\/p>\n\n\n\n<p>2. Kod\u0117l svarbus nesuvar\u017eytas susitraukimas?<br>Jis atspindi vidin\u012f med\u017eiagos elges\u012f be i\u0161orini\u0173 j\u0117g\u0173, tod\u0117l <strong>tikrosios susitraukimo charakteristikos<\/strong>.<\/p>\n\n\n\n<p>3. Kiek laiko bandiniai tur\u0117t\u0173 b\u016bti panardinti?<br>Paprastai 10 sekund\u017ei\u0173, ta\u010diau storesn\u0117ms ar naujoms med\u017eiagoms gali prireikti patvirtinimo, kad b\u016bt\u0173 u\u017etikrintas visi\u0161kas susitraukimas.<\/p>\n\n\n\n<p>4. Kuo skiriasi MD ir TD susitraukimas?<br>MD (ma\u0161inos kryptis) sutampa su pl\u0117vel\u0117s gamybos kryptimi, o TD yra statmena - abi \u0161ios kryptys turi skirting\u0105 poveik\u012f na\u0161umui.<\/p>\n\n\n\n<p>5. Gali <a href=\"https:\/\/store.astm.org\/d2732-14r25.html\" target=\"_blank\" rel=\"noreferrer noopener nofollow\">ASTM D2732<\/a> galima naudoti tirpikli\u0173 pagrindu pagamintam susitraukimui?<br>Ne, jis neatsi\u017evelgia \u012f susitraukim\u0105 d\u0117l tirpiklio praradimo.<\/p>\n\n\n\n<p><\/p>","protected":false},"excerpt":{"rendered":"<p>Pagal ASTM D2732 vertinamas plastikini\u0173 pl\u0117veli\u0173 nesuvar\u017eytas linijinis terminis susitraukimas, matuojant matmen\u0173 poky\u010dius po kontroliuojamo kaitinimo.<\/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\/lt\/wp-json\/wp\/v2\/standard\/10305","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.packqc.com\/lt\/wp-json\/wp\/v2\/standard"}],"about":[{"href":"https:\/\/www.packqc.com\/lt\/wp-json\/wp\/v2\/types\/standard"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.packqc.com\/lt\/wp-json\/wp\/v2\/media\/10306"}],"wp:attachment":[{"href":"https:\/\/www.packqc.com\/lt\/wp-json\/wp\/v2\/media?parent=10305"}],"wp:term":[{"taxonomy":"standard-category","embeddable":true,"href":"https:\/\/www.packqc.com\/lt\/wp-json\/wp\/v2\/standard-category?post=10305"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}