{"id":1261,"date":"2026-05-12T08:14:06","date_gmt":"2026-05-12T08:14:06","guid":{"rendered":"https:\/\/www.packtests.com\/?post_type=standard&#038;p=1261"},"modified":"2026-05-12T09:09:33","modified_gmt":"2026-05-12T09:09:33","slug":"astm-f1921","status":"publish","type":"standard","link":"https:\/\/www.packtests.com\/ja\/standard\/astm-f1921\/","title":{"rendered":"ASTM F1921"},"content":{"rendered":"<div data-elementor-type=\"wp-post\" data-elementor-id=\"1261\" class=\"elementor elementor-1261\" data-elementor-post-type=\"standard\">\n\t\t\t\t<div class=\"elementor-element elementor-element-5ec1237 e-flex e-con-boxed e-con e-parent\" data-id=\"5ec1237\" data-element_type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-b53c995 elementor-widget elementor-widget-text-editor\" data-id=\"b53c995\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<h2>ASTM F1921 and Hot Tack Test Method<\/h2><p>ASTM F1921 defines a <strong>laboratory method for measuring the strength of heat seals immediately after formation<\/strong>, before the material cools to ambient temperature. This property\u2014known as <em>hot tack strength<\/em>\u2014is critical in high-speed packaging environments, especially <strong>form-fill-seal (FFS)<\/strong> processes.<\/p><p>\u306b\u3064\u3044\u3066 <strong>hot tack test method<\/strong> simulates actual sealing conditions by applying controlled heat and pressure to thermoplastic films.<\/p><p>Unlike conventional seal strength tests performed at room temperature, ASTM F1921 and hot tack test method evaluates <strong>real-time seal integrity under thermal stress<\/strong>, making it highly relevant for production stability and packaging reliability.<\/p><h2>Hot Tack Test Process<\/h2><p>ASTM F1921 determines the strength of a heat seal immediately after it is formed. The test cycle includes sealing, opening of jaws, withdrawal, delay\/cooling, and separation of grips to measure the force.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-ef8e840 e-con-full e-flex e-con e-child\" data-id=\"ef8e840\" data-element_type=\"container\">\n\t\t<div class=\"elementor-element elementor-element-8140b4b e-con-full e-flex e-con e-child\" data-id=\"8140b4b\" data-element_type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-e756c01 elementor-widget__width-inherit elementor-position-top elementor-widget elementor-widget-image-box\" data-id=\"e756c01\" data-element_type=\"widget\" data-widget_type=\"image-box.default\">\n\t\t\t\t\t<div class=\"elementor-image-box-wrapper\"><figure class=\"elementor-image-box-img\"><img fetchpriority=\"high\" decoding=\"async\" width=\"300\" height=\"200\" src=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Hot-Tack-Testing-Process-1-Seal.webp\" class=\"attachment-large size-large wp-image-1278\" alt=\"Hot Tack Testing Process 1 Seal\" title=\"\" srcset=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Hot-Tack-Testing-Process-1-Seal.webp 300w, https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Hot-Tack-Testing-Process-1-Seal-18x12.webp 18w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/figure><div class=\"elementor-image-box-content\"><h3 class=\"elementor-image-box-title\">1. Seal<\/h3><p class=\"elementor-image-box-description\">Two strips are sealed under defined temperature, pressure and dwell time.<\/p><\/div><\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-4658d39 elementor-widget__width-initial elementor-view-default elementor-widget elementor-widget-icon\" data-id=\"4658d39\" data-element_type=\"widget\" data-widget_type=\"icon.default\">\n\t\t\t\t\t\t\t<div class=\"elementor-icon-wrapper\">\n\t\t\t<div class=\"elementor-icon\">\n\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-long-arrow-alt-right\" viewbox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M313.941 216H12c-6.627 0-12 5.373-12 12v56c0 6.627 5.373 12 12 12h301.941v46.059c0 21.382 25.851 32.09 40.971 16.971l86.059-86.059c9.373-9.373 9.373-24.569 0-33.941l-86.059-86.059c-15.119-15.119-40.971-4.411-40.971 16.971V216z\"><\/path><\/svg>\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-85446db elementor-widget__width-inherit elementor-position-top elementor-widget elementor-widget-image-box\" data-id=\"85446db\" data-element_type=\"widget\" data-widget_type=\"image-box.default\">\n\t\t\t\t\t<div class=\"elementor-image-box-wrapper\"><figure class=\"elementor-image-box-img\"><img decoding=\"async\" width=\"300\" height=\"200\" src=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Hot-Tack-Testing-Process-2-Open-Jaws.webp\" class=\"attachment-large size-large wp-image-1279\" alt=\"Hot Tack Testing Process 2 Open Jaws\" title=\"\" srcset=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Hot-Tack-Testing-Process-2-Open-Jaws.webp 300w, https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Hot-Tack-Testing-Process-2-Open-Jaws-18x12.webp 18w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/figure><div class=\"elementor-image-box-content\"><h3 class=\"elementor-image-box-title\">2. Open Jaws<\/h3><p class=\"elementor-image-box-description\">The jaws open and the sealed area is released.<\/p><\/div><\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-81869d6 elementor-widget__width-initial elementor-view-default elementor-widget elementor-widget-icon\" data-id=\"81869d6\" data-element_type=\"widget\" data-widget_type=\"icon.default\">\n\t\t\t\t\t\t\t<div class=\"elementor-icon-wrapper\">\n\t\t\t<div class=\"elementor-icon\">\n\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-long-arrow-alt-right\" viewbox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M313.941 216H12c-6.627 0-12 5.373-12 12v56c0 6.627 5.373 12 12 12h301.941v46.059c0 21.382 25.851 32.09 40.971 16.971l86.059-86.059c9.373-9.373 9.373-24.569 0-33.941l-86.059-86.059c-15.119-15.119-40.971-4.411-40.971 16.971V216z\"><\/path><\/svg>\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-82dcd8d elementor-widget__width-inherit elementor-position-top elementor-widget elementor-widget-image-box\" data-id=\"82dcd8d\" data-element_type=\"widget\" data-widget_type=\"image-box.default\">\n\t\t\t\t\t<div class=\"elementor-image-box-wrapper\"><figure class=\"elementor-image-box-img\"><img decoding=\"async\" width=\"300\" height=\"200\" src=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Hot-Tack-Testing-Process-3-Withdraw.webp\" class=\"attachment-large size-large wp-image-1280\" alt=\"Hot Tack Testing Process 3 Withdraw\" title=\"\" srcset=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Hot-Tack-Testing-Process-3-Withdraw.webp 300w, https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Hot-Tack-Testing-Process-3-Withdraw-18x12.webp 18w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/figure><div class=\"elementor-image-box-content\"><h3 class=\"elementor-image-box-title\">3. Withdraw<\/h3><p class=\"elementor-image-box-description\">The specimen is automatically withdrawn from between the jaws.<\/p><\/div><\/div>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-3657b98 e-con-full e-flex e-con e-child\" data-id=\"3657b98\" data-element_type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-e93267b elementor-widget__width-initial elementor-view-default elementor-widget elementor-widget-icon\" data-id=\"e93267b\" data-element_type=\"widget\" data-widget_type=\"icon.default\">\n\t\t\t\t\t\t\t<div class=\"elementor-icon-wrapper\">\n\t\t\t<div class=\"elementor-icon\">\n\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-long-arrow-alt-right\" viewbox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M313.941 216H12c-6.627 0-12 5.373-12 12v56c0 6.627 5.373 12 12 12h301.941v46.059c0 21.382 25.851 32.09 40.971 16.971l86.059-86.059c9.373-9.373 9.373-24.569 0-33.941l-86.059-86.059c-15.119-15.119-40.971-4.411-40.971 16.971V216z\"><\/path><\/svg>\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-17acaff elementor-widget__width-inherit elementor-position-top elementor-widget elementor-widget-image-box\" data-id=\"17acaff\" data-element_type=\"widget\" data-widget_type=\"image-box.default\">\n\t\t\t\t\t<div class=\"elementor-image-box-wrapper\"><figure class=\"elementor-image-box-img\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"200\" src=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Hot-Tack-Testing-Process-4-Delay-Cooling.webp\" class=\"attachment-large size-large wp-image-1281\" alt=\"Hot Tack Testing Process 4 Delay Cooling\" title=\"\" srcset=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Hot-Tack-Testing-Process-4-Delay-Cooling.webp 300w, https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Hot-Tack-Testing-Process-4-Delay-Cooling-18x12.webp 18w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/figure><div class=\"elementor-image-box-content\"><h3 class=\"elementor-image-box-title\">4. Delay \/ Cooling<\/h3><p class=\"elementor-image-box-description\">A preset delay (cooling time) begins after jaw opening.<\/p><\/div><\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-e6530af elementor-widget__width-initial elementor-view-default elementor-widget elementor-widget-icon\" data-id=\"e6530af\" data-element_type=\"widget\" data-widget_type=\"icon.default\">\n\t\t\t\t\t\t\t<div class=\"elementor-icon-wrapper\">\n\t\t\t<div class=\"elementor-icon\">\n\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-fas-long-arrow-alt-right\" viewbox=\"0 0 448 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M313.941 216H12c-6.627 0-12 5.373-12 12v56c0 6.627 5.373 12 12 12h301.941v46.059c0 21.382 25.851 32.09 40.971 16.971l86.059-86.059c9.373-9.373 9.373-24.569 0-33.941l-86.059-86.059c-15.119-15.119-40.971-4.411-40.971 16.971V216z\"><\/path><\/svg>\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-f33db0e elementor-widget__width-inherit elementor-position-top elementor-widget elementor-widget-image-box\" data-id=\"f33db0e\" data-element_type=\"widget\" data-widget_type=\"image-box.default\">\n\t\t\t\t\t<div class=\"elementor-image-box-wrapper\"><figure class=\"elementor-image-box-img\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"200\" src=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Hot-Tack-Testing-Process-5-Separate-Measure.webp\" class=\"attachment-large size-large wp-image-1282\" alt=\"Hot Tack Testing Process 5 Separate &amp; Measure\" title=\"\" srcset=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Hot-Tack-Testing-Process-5-Separate-Measure.webp 300w, https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Hot-Tack-Testing-Process-5-Separate-Measure-18x12.webp 18w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/figure><div class=\"elementor-image-box-content\"><h3 class=\"elementor-image-box-title\">5. Separate &amp; Measure<\/h3><p class=\"elementor-image-box-description\">Grips separate at a constant speed and the force required to open the seal is measured until failure.<\/p><\/div><\/div>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c1d4788 elementor-widget elementor-widget-text-editor\" data-id=\"c1d4788\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<h2>Key Variables in ASTM F1921 Testing<\/h2><ul><li><strong>Sealing temperature:<\/strong> Typically varied to generate a hot tack curve<\/li><li><strong>Dwell time:<\/strong><ul><li>\u226425 \u00b5m films: ~0.5 s<\/li><li>25\u201364 \u00b5m films: ~1.0 s<\/li><li>64 \u00b5m films: ~2.5 s<\/li><\/ul><\/li><li><strong>Sealing pressure:<\/strong> 15\u201330 N\/cm\u00b2<\/li><li><strong>Cooling time \/ delay time:<\/strong> Defines measurement timing<\/li><li><strong>Separation speed:<\/strong> Typically 200 mm\/min (Method A)<\/li><\/ul><p>These parameters directly influence the resulting <strong>hot seal strength of flexible packaging<\/strong> materials.<\/p><h2>Hot Tack Tester: Essential Equipment for ASTM F1921<\/h2><p>A <strong>hot tack tester<\/strong> is specifically designed to replicate the sealing and immediate peel process defined in ASTM F1921. Advanced systems\u2014such as those developed by Cell Instruments Co., Ltd.\u2014offer:<\/p><ul><li><strong>PLC-based control systems<\/strong> for repeatability<\/li><li><strong>PID temperature regulation (\u00b10.2\u00b0C accuracy)<\/strong><\/li><li><strong>Automated test cycles<\/strong> eliminating operator influence<\/li><li><strong>Adjustable test speeds and pressures<\/strong><\/li><li><strong>High-resolution force measurement<\/strong><\/li><\/ul>\t\t\t\t\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-696a839 e-con-full e-flex e-con e-child\" data-id=\"696a839\" data-element_type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-a44a8e6 elementor-widget elementor-widget-text-editor\" data-id=\"a44a8e6\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<h3>Recommended Solution<\/h3><p>The Cell Instruments HTT series supports:<\/p><ul><li><strong>Method A (Fixed Delay)<\/strong> \u305d\u3057\u3066 <strong>Method B (Variable Delay)<\/strong><\/li><li>Multiple test modes: hot tack, peel, tensile, heat seal<\/li><li>High-speed testing up to <strong>12000 mm\/min<\/strong> (HTT-02)<\/li><\/ul><p>This flexibility enables precise characterization of different materials and sealing behaviors.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1d56d80 elementor-widget elementor-widget-image\" data-id=\"1d56d80\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"400\" height=\"638\" src=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/ASTM-F1921-Hot-Tack-Tester.webp\" class=\"attachment-large size-large wp-image-1283\" alt=\"ASTM F1921 Hot Tack Tester\" srcset=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/ASTM-F1921-Hot-Tack-Tester.webp 400w, https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/ASTM-F1921-Hot-Tack-Tester-188x300.webp 188w, https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/ASTM-F1921-Hot-Tack-Tester-8x12.webp 8w\" sizes=\"(max-width: 400px) 100vw, 400px\" title=\"\">\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c31033e elementor-widget elementor-widget-text-editor\" data-id=\"c31033e\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<h2><strong>Hot Seal Strength of Flexible Packaging<\/strong><\/h2><p>\u306b\u3064\u3044\u3066 <strong>hot seal strength of flexible packaging<\/strong> determines whether a package can withstand stress immediately after sealing. Weak hot tack can lead to:<\/p><ul><li>Seal opening during filling<\/li><li>Product contamination or leakage<\/li><li>Reduced packaging efficiency<\/li><li>Increased waste and downtime<\/li><\/ul><p>ASTM F1921 helps manufacturers:<\/p><ul><li><strong>Rank material performance<\/strong><\/li><li><strong>Optimize sealing parameters<\/strong><\/li><li><strong>Ensure process robustness in FFS operations<\/strong><\/li><\/ul><h2>ASTM F1921 Test Methods<br \/>&#8212;Method A vs Method B<\/h2><p>ASTM F1921 specifies two distinct approaches:<\/p><h3>Method A \u2013 Fixed Delay<\/h3><ul><li>Measures seal strength at <strong>specific cooling times<\/strong><\/li><li>Produces a <strong>hot tack strength vs time curve<\/strong><\/li><li>Suitable for detailed cooling behavior analysis<\/li><\/ul><h3>Method B \u2013 Variable Delay<\/h3><ul><li>Measures <strong>maximum force after a selected delay<\/strong><\/li><li>Faster and simpler for routine QC testing<\/li><li>Ideal for <strong>production environments<\/strong><\/li><\/ul><h2>Failure Modes in Hot Tack Testing<\/h2><p>To correctly interpret ASTM F1921 results, understanding seal separation modes is essential. Different failure behaviors indicate different material or process issues.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-63ec2a0 e-con-full e-flex e-con e-child\" data-id=\"63ec2a0\" data-element_type=\"container\">\n\t\t<div class=\"elementor-element elementor-element-b7ab802 e-con-full e-grid e-con e-child\" data-id=\"b7ab802\" data-element_type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-34fc5c5 elementor-widget__width-inherit elementor-position-top elementor-widget elementor-widget-image-box\" data-id=\"34fc5c5\" data-element_type=\"widget\" data-widget_type=\"image-box.default\">\n\t\t\t\t\t<div class=\"elementor-image-box-wrapper\"><figure class=\"elementor-image-box-img\"><img loading=\"lazy\" decoding=\"async\" width=\"162\" height=\"122\" src=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-1.webp\" class=\"attachment-large size-large wp-image-1284\" alt=\"Failure Modes in Hot Tack Testing 1\" title=\"\" srcset=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-1.webp 162w, https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-1-16x12.webp 16w\" sizes=\"(max-width: 162px) 100vw, 162px\" \/><\/figure><div class=\"elementor-image-box-content\"><h3 class=\"elementor-image-box-title\">Adhesive Peel<\/h3><p class=\"elementor-image-box-description\"><p style=\"text-align: left\">Separation occurs at the interface between the two surfaces.<br><b>Indicates: <\/b>Poor interfacial bonding or insufficient heat\/pressure.<\/p><\/p><\/div><\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-9691fc8 elementor-widget__width-inherit elementor-position-top elementor-widget elementor-widget-image-box\" data-id=\"9691fc8\" data-element_type=\"widget\" data-widget_type=\"image-box.default\">\n\t\t\t\t\t<div class=\"elementor-image-box-wrapper\"><figure class=\"elementor-image-box-img\"><img loading=\"lazy\" decoding=\"async\" width=\"162\" height=\"122\" src=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-2.webp\" class=\"attachment-large size-large wp-image-1285\" alt=\"Failure Modes in Hot Tack Testing 2\" title=\"\" srcset=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-2.webp 162w, https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-2-16x12.webp 16w\" sizes=\"(max-width: 162px) 100vw, 162px\" \/><\/figure><div class=\"elementor-image-box-content\"><h3 class=\"elementor-image-box-title\">Cohesive Peel<\/h3><p class=\"elementor-image-box-description\"><p style=\"text-align: left\">Failure occurs within one of the polymer layers.<br><b>Indicates:<\/b> Strong interfacial bonding; material itself fails.<\/p><\/p><\/div><\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-b8ab6b4 elementor-widget__width-inherit elementor-position-top elementor-widget elementor-widget-image-box\" data-id=\"b8ab6b4\" data-element_type=\"widget\" data-widget_type=\"image-box.default\">\n\t\t\t\t\t<div class=\"elementor-image-box-wrapper\"><figure class=\"elementor-image-box-img\"><img loading=\"lazy\" decoding=\"async\" width=\"162\" height=\"122\" src=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-3.webp\" class=\"attachment-large size-large wp-image-1286\" alt=\"Failure Modes in Hot Tack Testing 3\" title=\"\" srcset=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-3.webp 162w, https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-3-16x12.webp 16w\" sizes=\"(max-width: 162px) 100vw, 162px\" \/><\/figure><div class=\"elementor-image-box-content\"><h3 class=\"elementor-image-box-title\">Delamination<\/h3><p class=\"elementor-image-box-description\"><p style=\"text-align: left\">Separation between layers of a multi-layer structure. <br><b>Indicates:<\/b> Weak bonding between layers in laminated materials.<\/p><\/p><\/div><\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-90ba3b6 elementor-widget__width-inherit elementor-position-top elementor-widget elementor-widget-image-box\" data-id=\"90ba3b6\" data-element_type=\"widget\" data-widget_type=\"image-box.default\">\n\t\t\t\t\t<div class=\"elementor-image-box-wrapper\"><figure class=\"elementor-image-box-img\"><img loading=\"lazy\" decoding=\"async\" width=\"162\" height=\"122\" src=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-4.webp\" class=\"attachment-large size-large wp-image-1287\" alt=\"Failure Modes in Hot Tack Testing 4\" title=\"\" srcset=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-4.webp 162w, https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-4-16x12.webp 16w\" sizes=\"(max-width: 162px) 100vw, 162px\" \/><\/figure><div class=\"elementor-image-box-content\"><h3 class=\"elementor-image-box-title\">Material Break<\/h3><p class=\"elementor-image-box-description\"><p style=\"text-align: left\">Film breaks away from the seal area<br><b>Indicates:<\/b> Seal is stronger than the substrate.<\/p><\/p><\/div><\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-f67fd38 elementor-widget__width-inherit elementor-position-top elementor-widget elementor-widget-image-box\" data-id=\"f67fd38\" data-element_type=\"widget\" data-widget_type=\"image-box.default\">\n\t\t\t\t\t<div class=\"elementor-image-box-wrapper\"><figure class=\"elementor-image-box-img\"><img loading=\"lazy\" decoding=\"async\" width=\"162\" height=\"122\" src=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-5.webp\" class=\"attachment-large size-large wp-image-1288\" alt=\"Failure Modes in Hot Tack Testing 5\" title=\"\" srcset=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-5.webp 162w, https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-5-16x12.webp 16w\" sizes=\"(max-width: 162px) 100vw, 162px\" \/><\/figure><div class=\"elementor-image-box-content\"><h3 class=\"elementor-image-box-title\">Remote Break<\/h3><p class=\"elementor-image-box-description\"><p style=\"text-align: left\">Break occurs at a location remote from the seal.<br><b>Indicates:<\/b> Seal is much stronger than the material.<\/p><\/p><\/div><\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-b467121 elementor-widget__width-inherit elementor-position-top elementor-widget elementor-widget-image-box\" data-id=\"b467121\" data-element_type=\"widget\" data-widget_type=\"image-box.default\">\n\t\t\t\t\t<div class=\"elementor-image-box-wrapper\"><figure class=\"elementor-image-box-img\"><img loading=\"lazy\" decoding=\"async\" width=\"162\" height=\"122\" src=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-6.webp\" class=\"attachment-large size-large wp-image-1289\" alt=\"Failure Modes in Hot Tack Testing 6\" title=\"\" srcset=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-6.webp 162w, https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-6-16x12.webp 16w\" sizes=\"(max-width: 162px) 100vw, 162px\" \/><\/figure><div class=\"elementor-image-box-content\"><h3 class=\"elementor-image-box-title\">Material Elongation<\/h3><p class=\"elementor-image-box-description\"><p style=\"text-align: left\">Unsealed material stretches significantly before breaking.<br><b>Indicates:<\/b> High ductility and flexibility of film.<\/p><\/p><\/div><\/div>\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-17b150b elementor-widget__width-inherit elementor-position-top elementor-widget elementor-widget-image-box\" data-id=\"17b150b\" data-element_type=\"widget\" data-widget_type=\"image-box.default\">\n\t\t\t\t\t<div class=\"elementor-image-box-wrapper\"><figure class=\"elementor-image-box-img\"><img loading=\"lazy\" decoding=\"async\" width=\"162\" height=\"122\" src=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-7.webp\" class=\"attachment-large size-large wp-image-1290\" alt=\"Failure Modes in Hot Tack Testing 7\" title=\"\" srcset=\"https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-7.webp 162w, https:\/\/www.packtests.com\/wp-content\/uploads\/2026\/05\/Failure-Modes-in-Hot-Tack-Testing-7-16x12.webp 16w\" sizes=\"(max-width: 162px) 100vw, 162px\" \/><\/figure><div class=\"elementor-image-box-content\"><h3 class=\"elementor-image-box-title\">Peel with Elongation<\/h3><p class=\"elementor-image-box-description\"><p style=\"text-align: left\">Peeling accompanied by significant elongation of the unsealed material.<br><b>Indicates:<\/b> Combination of adhesive failure and material ductility.<\/p><\/p><\/div><\/div>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-544c157 elementor-widget elementor-widget-text-editor\" data-id=\"544c157\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t\t\t\t\t\t<h2>Building a Hot Tack Curve for Process Optimization<\/h2><p>A <strong>hot tack curve<\/strong> plots seal strength versus temperature. It helps identify:<\/p><ul><li>Seal initiation temperature (SIT)<\/li><li>Optimal sealing window<\/li><li>Maximum hot tack strength<\/li><\/ul><p>This data enables engineers to <strong>fine-tune sealing parameters for consistent packaging performance<\/strong>.<\/p><h2>FAQs about ASTM F1921<\/h2><ol><li><strong> What is the main purpose of ASTM F1921?<\/strong><br \/>It evaluates the <strong>hot tack strength of thermoplastic seals immediately after sealing<\/strong>, ensuring packaging reliability during production.<\/li><li><strong> How is ASTM F1921 different from ASTM F88?<\/strong><br \/><a href=\"https:\/\/store.astm.org\/f1921_f1921m-12r23.html\" target=\"_blank\" rel=\"noopener nofollow\">ASTM F1921<\/a> measures <strong>hot seal strength<\/strong>, while ASTM F88 measures <strong>cold seal strength<\/strong> after cooling.<\/li><li><strong> Which industries rely on hot tack testing?<\/strong><br \/>Food, pharmaceutical, medical device, and flexible packaging industries rely heavily on this test.<\/li><li><strong> What is the difference between Method A and Method B?<\/strong><br \/>Method A measures strength over time; Method B records the maximum force after a delay.<\/li><li><strong> Why is hot tack important in FFS processes?<\/strong><br \/>Because seals experience stress before cooling, insufficient hot tack can cause <strong>seal failure during packaging<\/strong>.<\/li><\/ol>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>","protected":false},"excerpt":{"rendered":"<p>ASTM F1921 and Hot Tack Test Method ASTM F1921 defines a laboratory method for measuring the strength of heat seals immediately after formation, before the material cools to ambient temperature. This property\u2014known as hot tack strength\u2014is critical in high-speed packaging environments, especially form-fill-seal (FFS) processes. The hot tack test method simulates actual sealing conditions by applying controlled heat and pressure to thermoplastic films. Unlike conventional seal strength tests performed at room temperature, ASTM F1921 and hot tack test method evaluates real-time seal integrity under thermal stress, making it highly relevant for production stability and packaging reliability. Hot Tack Test Process ASTM F1921 determines the strength of a heat seal immediately [&hellip;]<\/p>","protected":false},"featured_media":0,"parent":0,"template":"","meta":{"_acf_changed":false},"standard-category":[64],"class_list":["post-1261","standard","type-standard","status-publish","hentry","standard-category-astm"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.packtests.com\/ja\/wp-json\/wp\/v2\/standard\/1261","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.packtests.com\/ja\/wp-json\/wp\/v2\/standard"}],"about":[{"href":"https:\/\/www.packtests.com\/ja\/wp-json\/wp\/v2\/types\/standard"}],"version-history":[{"count":5,"href":"https:\/\/www.packtests.com\/ja\/wp-json\/wp\/v2\/standard\/1261\/revisions"}],"predecessor-version":[{"id":1297,"href":"https:\/\/www.packtests.com\/ja\/wp-json\/wp\/v2\/standard\/1261\/revisions\/1297"}],"wp:attachment":[{"href":"https:\/\/www.packtests.com\/ja\/wp-json\/wp\/v2\/media?parent=1261"}],"wp:term":[{"taxonomy":"standard-category","embeddable":true,"href":"https:\/\/www.packtests.com\/ja\/wp-json\/wp\/v2\/standard-category?post=1261"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}