{"id":5109,"date":"2026-08-28T03:19:15","date_gmt":"2026-08-28T03:19:15","guid":{"rendered":"https:\/\/www.topchinapack.com\/?p=5109"},"modified":"2026-08-28T03:19:20","modified_gmt":"2026-08-28T03:19:20","slug":"frozen-food-packaging-material-science","status":"publish","type":"post","link":"https:\/\/www.topchinapack.com\/ja\/frozen-food-packaging-material-science\/","title":{"rendered":"Why Doesn\u2019t Frozen Food Packaging Crack at -18\u00b0C? The Material Science Behind Frozen Pizza Packaging"},"content":{"rendered":"<p class=\"wp-block-paragraph\">Walk into the frozen food section of a supermarket and pick up a bag of frozen French fries or a frozen pizza. Few people stop to think about one question: <strong>Why can this thin plastic packaging remain in a -18\u00b0C cold storage environment for a year without becoming brittle, cracking, or leaking?<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The answer lies in material science and precision manufacturing. What looks like an ordinary flexible packaging film is actually the result of multiple materials working together.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For frozen food brands, choosing the right <strong><a href=\"https:\/\/www.topchinapack.com\/ja\/?page_id=10\" target=\"_blank\" data-type=\"page\" data-id=\"22\" rel=\"noreferrer noopener\">\u30d5\u30ec\u30ad\u30b7\u30d6\u30eb\u98df\u54c1\u5305\u88c5\u30e1\u30fc\u30ab\u30fc<\/a><\/strong> is therefore important because packaging must maintain its mechanical strength, sealing performance, and flexibility under low-temperature conditions.<\/p>\n\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_75 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">\u76ee\u6b21<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"\u30c8\u30b0\u30eb\u76ee\u6b21\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">\u30c8\u30b0\u30eb<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewbox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewbox=\"0 0 24 24\" version=\"1.2\" baseprofile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.topchinapack.com\/ja\/frozen-food-packaging-material-science\/#Plastic_Can_Also_%E2%80%9CFreeze%E2%80%9D\" >Plastic Can Also \u201cFreeze\u201d<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.topchinapack.com\/ja\/frozen-food-packaging-material-science\/#Three_Layers_Working_Together\" >Three Layers Working Together<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.topchinapack.com\/ja\/frozen-food-packaging-material-science\/#Printing_Is_More_Than_Just_Adding_a_Pattern\" >Printing Is More Than Just Adding a Pattern<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.topchinapack.com\/ja\/frozen-food-packaging-material-science\/#Lamination_Bonding_Different_Materials_Together\" >Lamination: Bonding Different Materials Together<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.topchinapack.com\/ja\/frozen-food-packaging-material-science\/#Sealing_The_Final_Line_of_Defense\" >Sealing: The Final Line of Defense<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.topchinapack.com\/ja\/frozen-food-packaging-material-science\/#The_Invisible_Safety_Requirements\" >The Invisible Safety Requirements<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.topchinapack.com\/ja\/frozen-food-packaging-material-science\/#Conclusion\" >\u7d50\u8ad6<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Plastic_Can_Also_%E2%80%9CFreeze%E2%80%9D\"><\/span>Plastic Can Also \u201cFreeze\u201d<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Ordinary plastic bags can become brittle after prolonged exposure to low temperatures. This happens because low temperatures reduce the flexibility of polymer molecular chains, changing the material from something like a rubber band into something closer to a glass rod.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Frozen food packaging cannot behave this way. It needs to withstand handling, stacking, and dropping at <strong>-18\u00b0C or even -35\u00b0C<\/strong>, while keeping the package properly sealed.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This requires a key property: <strong>low-temperature toughness<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\uff5e\u306b\u3064\u3044\u3066\u306f <strong>frozen food packaging manufacturer<\/strong>, material selection must therefore consider not only normal-temperature performance but also how the film behaves throughout the frozen storage and transportation process.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Three_Layers_Working_Together\"><\/span>Three Layers Working Together<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Frozen food packaging rarely relies on a single layer of plastic. Instead, it commonly uses a <strong>multilayer laminated structure<\/strong>, such as <strong>PET\/NY\/PE<\/strong>.<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Layer<\/th><th>\u7d20\u6750<\/th><th>\u6a5f\u80fd<\/th><\/tr><\/thead><tbody><tr><td>Outer layer<\/td><td>PET (Polyester)<\/td><td>Provides stiffness and printability, acting like the structural \u201cskeleton\u201d of the package<\/td><\/tr><tr><td>Middle layer<\/td><td>NY (Nylon)<\/td><td>Provides puncture resistance and low-temperature performance, helping prevent ice, bones, or sharp food ingredients from damaging the package<\/td><\/tr><tr><td>Inner layer<\/td><td>PE\uff08\u30dd\u30ea\u30a8\u30c1\u30ec\u30f3\uff09<\/td><td>Serves as the heat-sealing layer<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">In this structure, the PE layer can use special <strong>metallocene PE (mPE)<\/strong>, which can remain flexible even at temperatures down to around <strong>-40\u00b0C<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ordinary PE can become brittle at low temperatures, while <strong>mPE<\/strong> has a more controlled molecular structure that helps maintain flexibility under frozen conditions.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Printing_Is_More_Than_Just_Adding_a_Pattern\"><\/span>Printing Is More Than Just Adding a Pattern<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The attractive graphics on frozen food packaging can be printed using <strong>two-component polyurethane cold-resistant inks<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Ordinary inks may become brittle or peel at low temperatures and can also create concerns regarding unwanted substance migration.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Another important factor is <strong>solvent residue control<\/strong>. Solvents such as ethyl acetate and isopropyl alcohol are used during printing. If excessive residue remains, it can create odor or contamination concerns.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The original production requirement specifies total residual solvents of <strong>\u22645 mg\/m\u00b2<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">After printing, the flexible packaging film needs to remain in a temperature- and humidity-controlled curing room for approximately <strong>48\u201372 hours<\/strong>, allowing solvents to evaporate sufficiently and the adhesive to fully cross-link.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\uff5e\u306b\u3064\u3044\u3066\u306f <strong><a href=\"https:\/\/www.topchinapack.com\/ja\/custom-solution\/\" target=\"_blank\" data-type=\"page\" data-id=\"358\" rel=\"noreferrer noopener\">custom frozen food packaging<\/a><\/strong> project, these printing and curing processes need to be considered together with the final packaging application.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Lamination_Bonding_Different_Materials_Together\"><\/span>Lamination: Bonding Different Materials Together<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Different film materials cannot simply be placed together. They need to be bonded through <strong>dry lamination<\/strong> using <strong>freezer-resistant polyurethane adhesive<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">One important detail is that the curing temperature should not be excessively high. Temperatures above 60\u00b0C may negatively affect the flexibility of the adhesive layer at low temperatures.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The recommended curing temperature is approximately <strong>45\u201350\u00b0C<\/strong>, with curing taking more than two days.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">If the curing process is rushed, the adhesive layer may later experience delamination during long-term frozen storage.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\uff5e\u306b\u3064\u3044\u3066\u306f <strong><a href=\"https:\/\/www.topchinapack.com\/ja\/?page_id=10\" target=\"_blank\" data-type=\"page\" data-id=\"22\" rel=\"noreferrer noopener\">flexible packaging manufacture<\/a>r<\/strong>, controlling the lamination and curing process is therefore essential for maintaining package integrity in frozen applications.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Sealing_The_Final_Line_of_Defense\"><\/span>Sealing: The Final Line of Defense<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Even strong packaging materials cannot compensate for poor sealing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Frozen food packaging machines may seal approximately <strong>80\u2013120 bags per minute<\/strong>, so the heat-sealing layer needs to maintain stable sealing performance across a relatively broad temperature range of <strong>120\u2013160\u00b0C<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Before shipment, each production batch can undergo several quality checks:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Heat-seal strength test:<\/strong> The seal should withstand a tensile force of <strong>\u226540 N<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Negative-pressure sealing test:<\/strong> The package is vacuum-tested to <strong>-0.08 MPa for 30 seconds<\/strong> without leakage.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Frozen drop test:<\/strong> A package filled with water is frozen solid and dropped freely from a height of <strong>1.2 meters<\/strong> without breaking.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">These tests help verify whether the frozen food packaging film can maintain its performance during storage and transportation.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"The_Invisible_Safety_Requirements\"><\/span>The Invisible Safety Requirements<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Frozen food packaging is a type of <strong>food-contact packaging<\/strong>, so products exported to different markets need to comply with the corresponding food-contact regulations.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f8b\u3048\u3070\u3001\u3053\u3046\u3060\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>United States:<\/strong> FDA 21 CFR requirements<\/li>\n\n\n\n<li><strong>European Union:<\/strong> EU 10\/2011 requirements<\/li>\n\n\n\n<li><strong>Other markets:<\/strong> Applicable local food-contact material and migration testing requirements<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">This means that factors ranging from heavy metals in printing pigments to potential migration from adhesives into food products need to be evaluated.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Total migration and other relevant testing indicators may also need to be verified through laboratory testing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For international buyers, confirming applicable food-contact requirements with the packaging supplier before production can help reduce compliance risks later in the project.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Conclusion\"><\/span>\u7d50\u8ad6<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The next time you take a perfectly intact bag of frozen French fries or a frozen pizza out of the freezer, take another look at the thin layer of packaging around it.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Behind that packaging are carefully selected material structures, controlled printing and solvent residues, controlled lamination and curing processes, and strict sealing and quality testing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A frozen pizza may have a shelf life of <strong>12 months<\/strong>, but its packaging needs to withstand low temperatures and transportation conditions throughout that entire period without losing its protective function.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is the invisible strength of modern flexible food packaging manufacturing.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For brands sourcing frozen food packaging, working with an experienced <strong><a href=\"https:\/\/www.topchinapack.com\/ja\/?page_id=10\" target=\"_blank\" data-type=\"page\" data-id=\"22\" rel=\"noreferrer noopener\">\u30d5\u30ec\u30ad\u30b7\u30d6\u30eb\u98df\u54c1\u5305\u88c5\u30e1\u30fc\u30ab\u30fc<\/a><\/strong> can help connect material selection, printing, lamination, sealing, and quality control into one production process.<\/p>","protected":false},"excerpt":{"rendered":"<p>Walk into the frozen food section of a supermarket and pick up a bag of frozen French fries or a frozen pizza. Few people stop to think about one question: Why can this thin plastic packaging remain in a -18\u00b0C cold storage environment for a year without becoming brittle, cracking, or leaking? The answer lies in material science and precision manufacturing. What looks like an ordinary flexible packaging film is actually the result of multiple materials working together. For frozen food brands, choosing the right flexible food packaging manufacturer is therefore important because packaging must maintain its mechanical strength, sealing performance, and flexibility under low-temperature conditions. Plastic Can Also \u201cFreeze\u201d [&hellip;]<\/p>","protected":false},"author":1,"featured_media":5114,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[17],"tags":[],"class_list":["post-5109","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blogs-news"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.topchinapack.com\/ja\/wp-json\/wp\/v2\/posts\/5109","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.topchinapack.com\/ja\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.topchinapack.com\/ja\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.topchinapack.com\/ja\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.topchinapack.com\/ja\/wp-json\/wp\/v2\/comments?post=5109"}],"version-history":[{"count":0,"href":"https:\/\/www.topchinapack.com\/ja\/wp-json\/wp\/v2\/posts\/5109\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.topchinapack.com\/ja\/wp-json\/wp\/v2\/media\/5114"}],"wp:attachment":[{"href":"https:\/\/www.topchinapack.com\/ja\/wp-json\/wp\/v2\/media?parent=5109"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.topchinapack.com\/ja\/wp-json\/wp\/v2\/categories?post=5109"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.topchinapack.com\/ja\/wp-json\/wp\/v2\/tags?post=5109"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}