{"id":7090,"date":"2025-07-30T10:28:55","date_gmt":"2025-07-30T02:28:55","guid":{"rendered":"https:\/\/www.packqc.com\/?p=7090"},"modified":"2025-09-12T08:34:04","modified_gmt":"2025-09-12T00:34:04","slug":"bending-stiffness-test","status":"publish","type":"post","link":"https:\/\/www.packqc.com\/nn\/bending-stiffness-test\/","title":{"rendered":"ISO 5628 Guide with Bending Stiffness Testing Machine Insights"},"content":{"rendered":"<div data-elementor-type=\"wp-post\" data-elementor-id=\"7090\" class=\"elementor elementor-7090\" data-elementor-post-type=\"post\">\n\t\t\t\t<div class=\"elementor-element elementor-element-ea52c1c e-flex e-con-boxed e-con e-parent\" data-id=\"ea52c1c\" 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-4b7ffbd elementor-widget elementor-widget-heading\" data-id=\"4b7ffbd\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h1 class=\"elementor-heading-title elementor-size-default\">ISO 5628 Guide with Bending Stiffness Testing Machine Insights<\/h1>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-f374322 e-flex e-con-boxed e-con e-parent\" data-id=\"f374322\" 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-43d0885 elementor-widget__width-initial elementor-widget elementor-widget-text-editor\" data-id=\"43d0885\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"522\" data-end=\"990\">The <strong data-start=\"526\" data-end=\"552\">bending stiffness test<\/strong> is a critical material property evaluation method used across industries including packaging, medical devices, pharmaceuticals, textiles, and paperboard production. This test measures a material\u2019s resistance to bending and provides insights into its rigidity, flexibility, and structural performance. <a href=\"https:\/\/www.iso.org\/standard\/76347.html\" target=\"_blank\" rel=\"noopener nofollow\"><strong data-start=\"854\" data-end=\"871\">ISO 5628:2019<\/strong><\/a> outlines standardized principles for executing such tests using two-point, three-point, or four-point bending methods.<\/p><p data-start=\"992\" data-end=\"1437\">To ensure accurate results, manufacturers and quality control professionals must follow the correct procedures, use compliant equipment, and understand how variables like material thickness, modulus of elasticity, and support conditions affect results. This article guides you through the proper execution of the bending stiffness test while recommending reliable instrumentation such as the <strong data-start=\"1384\" data-end=\"1436\">Cell Instruments WTD-01 Bending Stiffness Tester<\/strong>.<\/p>\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-ced6aee elementor-widget elementor-widget-image\" data-id=\"ced6aee\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/www.packqc.com\/nn\/\">\n\t\t\t\t\t\t\t<img fetchpriority=\"high\" decoding=\"async\" width=\"600\" height=\"600\" src=\"https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/WTD-01-Bending-Stiffness-Tester_\u526f\u672c_\u526f\u672c.webp\" class=\"attachment-large size-large wp-image-7124\" alt=\"\" srcset=\"https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/WTD-01-Bending-Stiffness-Tester_\u526f\u672c_\u526f\u672c.webp 600w, https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/WTD-01-Bending-Stiffness-Tester_\u526f\u672c_\u526f\u672c-300x300.webp 300w, https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/WTD-01-Bending-Stiffness-Tester_\u526f\u672c_\u526f\u672c-100x100.webp 100w, https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/WTD-01-Bending-Stiffness-Tester_\u526f\u672c_\u526f\u672c-150x150.webp 150w, https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/WTD-01-Bending-Stiffness-Tester_\u526f\u672c_\u526f\u672c-12x12.webp 12w\" sizes=\"(max-width: 600px) 100vw, 600px\">\t\t\t\t\t\t\t\t<\/a>\n\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\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-fcea402 e-flex e-con-boxed e-con e-parent\" data-id=\"fcea402\" 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-78240c3 elementor-widget elementor-widget-heading\" data-id=\"78240c3\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Stiffness Test Method Overview Based on ISO 5628<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-acd9c29 e-flex e-con-boxed e-con e-parent\" data-id=\"acd9c29\" 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-6e7200a elementor-widget elementor-widget-text-editor\" data-id=\"6e7200a\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"1497\" data-end=\"1655\">The <strong data-start=\"1501\" data-end=\"1526\">stiffness test method<\/strong> described in ISO 5628 is grounded in beam theory, where the <strong data-start=\"1587\" data-end=\"1613\">bending stiffness (Sb)<\/strong> of a homogeneous sample is determined by:<\/p><p style=\"text-align: center;\" data-start=\"1497\" data-end=\"1655\"><strong style=\"font-size: 16px;\" data-start=\"1659\" data-end=\"1679\">Sb = (E \u00d7 I) \/ b<\/strong><\/p><p data-start=\"1681\" data-end=\"1689\">Where:<\/p><ul><li data-start=\"1692\" data-end=\"1736\"><em data-start=\"1692\" data-end=\"1695\">E<\/em> is the elastic modulus of the material<\/li><li data-start=\"1739\" data-end=\"1776\"><em data-start=\"1739\" data-end=\"1742\">I<\/em> is the second moment of inertia<\/li><li data-start=\"1779\" data-end=\"1813\"><em data-start=\"1779\" data-end=\"1782\">b<\/em> is the width of the specimen<\/li><\/ul><p data-start=\"1815\" data-end=\"1896\">According to ISO 5628:2019, stiffness can be calculated using three approaches:<\/p><ol><li data-start=\"1900\" data-end=\"1991\">Measuring the maximum slope of the <strong data-start=\"1935\" data-end=\"1959\">force vs. deflection<\/strong> or <strong data-start=\"1963\" data-end=\"1982\">force vs. angle<\/strong> curve.<\/li><li data-start=\"1995\" data-end=\"2092\">Applying a fixed deflection\/angle and measuring the corresponding force after a specified time.<\/li><li data-start=\"2096\" data-end=\"2181\">Applying a constant force and recording the deflection or angle after a fixed period.<\/li><\/ol><p data-start=\"2183\" data-end=\"2309\">Each method must be executed under well-defined conditions, with <strong data-start=\"2248\" data-end=\"2264\">testing rate<\/strong> and <strong data-start=\"2269\" data-end=\"2291\">measurement timing<\/strong> reported clearly.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-3a9974f e-flex e-con-boxed e-con e-parent\" data-id=\"3a9974f\" 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-345f0ba elementor-widget elementor-widget-heading\" data-id=\"345f0ba\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Equipment Selection: Use of a Stiffness Testing Machine<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-079a5bd e-flex e-con-boxed e-con e-parent\" data-id=\"079a5bd\" 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-9afc859 elementor-widget elementor-widget-text-editor\" data-id=\"9afc859\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"2376\" data-end=\"2522\">Choosing a suitable <strong data-start=\"2396\" data-end=\"2425\">stiffness testing machine<\/strong> is essential for accurate results and compliance with ISO standards. Key specifications include:<\/p><ul><li data-start=\"2526\" data-end=\"2572\">Adjustable bending length with \u00b11% precision<\/li><li data-start=\"2575\" data-end=\"2661\">Ability to record <strong data-start=\"2593\" data-end=\"2620\">force versus deflection<\/strong> or <strong data-start=\"2624\" data-end=\"2659\">force versus angular deflection<\/strong><\/li><li data-start=\"2664\" data-end=\"2720\">Sensitivity within \u00b12.5% of the full measurement range<\/li><li data-start=\"2723\" data-end=\"2781\">Stable supporting anvils that minimize testing artifacts<\/li><\/ul><p data-start=\"2783\" data-end=\"3100\">The <strong data-start=\"2787\" data-end=\"2839\">Cell Instruments WTD-01 Bending Stiffness Tester<\/strong> fully meets these requirements. It provides automated, precise data collection and curve analysis across all ISO 5628-approved testing configurations. It&#8217;s a robust solution for laboratories aiming to ensure product performance through reliable stiffness data.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-4726e31 e-flex e-con-boxed e-con e-parent\" data-id=\"4726e31\" 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-fe9c91f elementor-widget elementor-widget-heading\" data-id=\"fe9c91f\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Sample Preparation and Testing Conditions<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-f644a76 e-grid e-con-boxed e-con e-parent\" data-id=\"f644a76\" data-element_type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t<div class=\"elementor-element elementor-element-a51a5f4 e-con-full e-flex e-con e-child\" data-id=\"a51a5f4\" data-element_type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-3b1aabd elementor-widget elementor-widget-heading\" data-id=\"3b1aabd\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Sampling  1<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-8a59d5b elementor-widget elementor-widget-text-editor\" data-id=\"8a59d5b\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>For batch analysis, select specimens according to <strong data-start=\"3218\" data-end=\"3229\">ISO 186<\/strong>. Ensure test pieces are representative of the lot to ensure valid conclusions.<\/p>\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-b9bf964 elementor-widget elementor-widget-image\" data-id=\"b9bf964\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/www.packqc.com\/nn\/\">\n\t\t\t\t\t\t\t<img decoding=\"async\" width=\"1024\" height=\"768\" src=\"https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/DJI_20230420_161326_147_\u526f\u672c_\u526f\u672c-1024x768.webp\" class=\"attachment-large size-large wp-image-7129\" alt=\"\" srcset=\"https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/DJI_20230420_161326_147_\u526f\u672c_\u526f\u672c-1024x768.webp 1024w, https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/DJI_20230420_161326_147_\u526f\u672c_\u526f\u672c-scaled-600x450.webp 600w, https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/DJI_20230420_161326_147_\u526f\u672c_\u526f\u672c-300x225.webp 300w, https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/DJI_20230420_161326_147_\u526f\u672c_\u526f\u672c-768x576.webp 768w, https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/DJI_20230420_161326_147_\u526f\u672c_\u526f\u672c-1536x1152.webp 1536w, https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/DJI_20230420_161326_147_\u526f\u672c_\u526f\u672c-2048x1536.webp 2048w, https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/DJI_20230420_161326_147_\u526f\u672c_\u526f\u672c-16x12.webp 16w\" sizes=\"(max-width: 1024px) 100vw, 1024px\">\t\t\t\t\t\t\t\t<\/a>\n\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>\n\t\t<div class=\"elementor-element elementor-element-6140a88 e-con-full e-flex e-con e-child\" data-id=\"6140a88\" data-element_type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-b0daa4a elementor-widget elementor-widget-heading\" data-id=\"b0daa4a\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Conditioning  2<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c96ff83 elementor-widget elementor-widget-text-editor\" data-id=\"c96ff83\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Condition specimens as per <strong data-start=\"3356\" data-end=\"3367\">ISO 187<\/strong> at standard temperature and humidity. Retain specimens in this environment during the entire testing process.<\/p>\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-a65eaa1 elementor-widget elementor-widget-image\" data-id=\"a65eaa1\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<a href=\"https:\/\/www.packqc.com\/nn\/\">\n\t\t\t\t\t\t\t<img decoding=\"async\" width=\"1024\" height=\"768\" src=\"https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/DJI_20230420_161423_151_\u526f\u672c_\u526f\u672c-1024x768.webp\" class=\"attachment-large size-large wp-image-7130\" alt=\"Bending stiffness test method\" srcset=\"https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/DJI_20230420_161423_151_\u526f\u672c_\u526f\u672c-1024x768.webp 1024w, https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/DJI_20230420_161423_151_\u526f\u672c_\u526f\u672c-scaled-600x450.webp 600w, https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/DJI_20230420_161423_151_\u526f\u672c_\u526f\u672c-300x225.webp 300w, https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/DJI_20230420_161423_151_\u526f\u672c_\u526f\u672c-768x576.webp 768w, https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/DJI_20230420_161423_151_\u526f\u672c_\u526f\u672c-1536x1152.webp 1536w, https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/DJI_20230420_161423_151_\u526f\u672c_\u526f\u672c-2048x1536.webp 2048w, https:\/\/www.packqc.com\/wp-content\/uploads\/2025\/07\/DJI_20230420_161423_151_\u526f\u672c_\u526f\u672c-16x12.webp 16w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/>\t\t\t\t\t\t\t\t<\/a>\n\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>\n\t\t<div class=\"elementor-element elementor-element-0689448 e-con-full e-flex e-con e-child\" data-id=\"0689448\" data-element_type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-01f90f1 elementor-widget elementor-widget-heading\" data-id=\"01f90f1\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Test Piece Preparation  3<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-b615f36 elementor-widget elementor-widget-text-editor\" data-id=\"b615f36\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<ul><li data-start=\"3510\" data-end=\"3549\">Cut test pieces from undamaged sheets<\/li><li data-start=\"3552\" data-end=\"3590\">Avoid watermarks, wrinkles, or folds<\/li><li data-start=\"3593\" data-end=\"3636\">Ensure long edges are parallel within \u00b11%<\/li><li data-start=\"3639\" data-end=\"3731\">Prepare a minimum of 10 specimens for each direction (machine direction and cross direction)<\/li><\/ul><p data-start=\"3733\" data-end=\"3925\">The definition of the <strong data-start=\"3755\" data-end=\"3771\">&#8220;upper side&#8221;<\/strong> of the test piece is critical, as bending must be performed in both directions (upwards and downwards), and results averaged to eliminate curvature bias.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-670b26d e-flex e-con-boxed e-con e-parent\" data-id=\"670b26d\" 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-5bfcca0 elementor-widget elementor-widget-heading\" data-id=\"5bfcca0\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Testing Procedure<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-f5559f9 e-flex e-con-boxed e-con e-parent\" data-id=\"f5559f9\" 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-d879eda elementor-widget__width-initial elementor-widget elementor-widget-video\" data-id=\"d879eda\" data-element_type=\"widget\" data-settings=\"{&quot;youtube_url&quot;:&quot;https:\\\/\\\/youtu.be\\\/yuaDfFkcMtA?si=LEu3ImiQ_PhYgt6C&quot;,&quot;autoplay&quot;:&quot;yes&quot;,&quot;play_on_mobile&quot;:&quot;yes&quot;,&quot;mute&quot;:&quot;yes&quot;,&quot;loop&quot;:&quot;yes&quot;,&quot;video_type&quot;:&quot;youtube&quot;,&quot;controls&quot;:&quot;yes&quot;}\" data-widget_type=\"video.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-wrapper elementor-open-inline\">\n\t\t\t<div class=\"elementor-video\"><\/div>\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2cb4a1c elementor-widget elementor-widget-text-editor\" data-id=\"2cb4a1c\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"3954\" data-end=\"4205\">Before conducting the <strong data-start=\"3976\" data-end=\"4002\">bending stiffness test<\/strong>, determine thickness using <strong data-start=\"4030\" data-end=\"4041\">ISO 534<\/strong> (for paper and board) or <strong data-start=\"4067\" data-end=\"4079\">ISO 3034<\/strong> (for corrugated board). Note that bulk thickness and sheet thickness yield different results and must be handled accordingly.<\/p><ul><li data-start=\"4209\" data-end=\"4251\">Place the sample on the stiffness tester<\/li><li data-start=\"4254\" data-end=\"4337\">Conduct five tests bending towards the upper side and five towards the lower side<\/li><li data-start=\"4340\" data-end=\"4386\">Plot force vs. deflection or force vs. angle<\/li><li data-start=\"4389\" data-end=\"4451\">Use the linear portion of the curve for stiffness evaluation<\/li><li data-start=\"4454\" data-end=\"4525\">Average all test results and report using <strong data-start=\"4496\" data-end=\"4525\">three significant figures<\/strong><\/li><\/ul><p data-start=\"4527\" data-end=\"4626\">Important: Ensure that each specimen is as <strong data-start=\"4570\" data-end=\"4590\">flat as possible<\/strong> to avoid errors from pre-curvature.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-1f8f3e3 e-flex e-con-boxed e-con e-parent\" data-id=\"1f8f3e3\" 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-aa9bcee elementor-widget elementor-widget-heading\" data-id=\"aa9bcee\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Evaluation and Calculation<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-6f10460 e-flex e-con-boxed e-con e-parent\" data-id=\"6f10460\" 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-eee373f elementor-widget elementor-widget-text-editor\" data-id=\"eee373f\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"4664\" data-end=\"4702\">Results can be calculated by either:<\/p><ul><li data-start=\"4705\" data-end=\"4770\">Using the <strong data-start=\"4715\" data-end=\"4732\">linear region<\/strong> of the force-deflection\/angle curve<\/li><li data-start=\"4773\" data-end=\"4847\">Applying the <strong data-start=\"4786\" data-end=\"4821\">recommended deflection or angle<\/strong> and measuring the force<\/li><li data-start=\"4850\" data-end=\"4916\">Recording the <strong data-start=\"4864\" data-end=\"4881\">maximum force<\/strong> and the corresponding deflection<\/li><\/ul><p data-start=\"4918\" data-end=\"5082\">Choose the evaluation method based on your test configuration (two-point, three-point, or four-point) and ensure that data is averaged across all valid test pieces.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-b2d1a28 e-flex e-con-boxed e-con e-parent\" data-id=\"b2d1a28\" 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-55d8922 elementor-widget elementor-widget-heading\" data-id=\"55d8922\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Why Choose Cell Instruments Bending Stiffness Testing<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-2f8cfb1 e-flex e-con-boxed e-con e-parent\" data-id=\"2f8cfb1\" 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-4de75da elementor-widget elementor-widget-text-editor\" data-id=\"4de75da\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"5158\" data-end=\"5291\">For manufacturers and QC labs seeking efficiency and ISO compliance, the <strong data-start=\"5231\" data-end=\"5283\"><a href=\"https:\/\/www.packqc.com\/nn\/\">Cell Instruments<\/a> WTD-01 Bending Stiffness Tester<\/strong> offers:<\/p><ul><li data-start=\"5295\" data-end=\"5345\">Full compatibility with ISO 5628 test procedures<\/li><li data-start=\"5348\" data-end=\"5392\">High precision and consistent data outputs<\/li><li data-start=\"5395\" data-end=\"5427\">Multi-point testing capability<\/li><li data-start=\"5430\" data-end=\"5480\">User-friendly interface for simplified operation<\/li><li data-start=\"5483\" data-end=\"5585\">Suitable for a wide range of materials including paperboard, flexible packaging, and medical laminates<\/li><\/ul><p data-start=\"5587\" data-end=\"5778\">This instrument is ideal for packaging manufacturers, medical device developers, and material testing labs who need <strong data-start=\"5703\" data-end=\"5738\">reliable bending stiffness test<\/strong> results under ISO-regulated conditions.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-12ec6bd e-flex e-con-boxed e-con e-parent\" data-id=\"12ec6bd\" 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-ca831cb elementor-widget elementor-widget-heading\" data-id=\"ca831cb\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Conclusion<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-eeae7d4 e-flex e-con-boxed e-con e-parent\" data-id=\"eeae7d4\" 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-15ae6ce elementor-widget elementor-widget-text-editor\" data-id=\"15ae6ce\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p data-start=\"5800\" data-end=\"6176\">Executing a <strong data-start=\"5812\" data-end=\"5838\">bending stiffness test<\/strong> in compliance with <strong data-start=\"5858\" data-end=\"5875\">ISO 5628:2019<\/strong> requires more than just measuring force and deflection\u2014it demands thoughtful sample preparation, accurate instrumentation, and careful calculation. Selecting a capable <strong data-start=\"6044\" data-end=\"6073\">stiffness testing machine<\/strong>, like the <strong data-start=\"6084\" data-end=\"6111\">Cell Instruments WTD-01<\/strong>, ensures reliable results and supports rigorous quality control.<\/p><p data-start=\"6178\" data-end=\"6381\">By adhering to the methods and principles outlined here, professionals in packaging, medical, pharmaceutical, and related sectors can confidently assess material performance and uphold product standards.<\/p>\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-24c320b elementor-align-center elementor-widget elementor-widget-button\" data-id=\"24c320b\" data-element_type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<div class=\"elementor-button-wrapper\">\n\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm\" href=\"mailto:packqc@celtec.cn\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t<span class=\"elementor-button-icon\">\n\t\t\t\t<svg aria-hidden=\"true\" class=\"e-font-icon-svg e-far-check-circle\" viewbox=\"0 0 512 512\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\"><path d=\"M256 8C119.033 8 8 119.033 8 256s111.033 248 248 248 248-111.033 248-248S392.967 8 256 8zm0 48c110.532 0 200 89.451 200 200 0 110.532-89.451 200-200 200-110.532 0-200-89.451-200-200 0-110.532 89.451-200 200-200m140.204 130.267l-22.536-22.718c-4.667-4.705-12.265-4.736-16.97-.068L215.346 303.697l-59.792-60.277c-4.667-4.705-12.265-4.736-16.97-.069l-22.719 22.536c-4.705 4.667-4.736 12.265-.068 16.971l90.781 91.516c4.667 4.705 12.265 4.736 16.97.068l172.589-171.204c4.704-4.668 4.734-12.266.067-16.971z\"><\/path><\/svg>\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Contact Us<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\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>ISO 5628 Guide with Bending Stiffness Testing Machine Insights The bending stiffness test is a critical material property evaluation method used across industries including packaging, medical devices, pharmaceuticals, textiles, and paperboard production. This test measures a material\u2019s resistance to bending and provides insights into its rigidity, flexibility, and structural performance. ISO 5628:2019 outlines standardized principles [&hellip;]<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"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":"","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":""}},"footnotes":""},"categories":[1],"tags":[],"class_list":["post-7090","post","type-post","status-publish","format-standard","hentry","category-blog"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.packqc.com\/nn\/wp-json\/wp\/v2\/posts\/7090","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.packqc.com\/nn\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.packqc.com\/nn\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.packqc.com\/nn\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.packqc.com\/nn\/wp-json\/wp\/v2\/comments?post=7090"}],"version-history":[{"count":0,"href":"https:\/\/www.packqc.com\/nn\/wp-json\/wp\/v2\/posts\/7090\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.packqc.com\/nn\/wp-json\/wp\/v2\/media?parent=7090"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.packqc.com\/nn\/wp-json\/wp\/v2\/categories?post=7090"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.packqc.com\/nn\/wp-json\/wp\/v2\/tags?post=7090"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}