{"id":2912,"date":"2025-04-04T14:41:00","date_gmt":"2025-04-04T14:41:00","guid":{"rendered":"http:\/\/tetravision.be\/case\/3-componenten-plastic-schaar\/"},"modified":"2026-02-13T13:15:29","modified_gmt":"2026-02-13T13:15:29","slug":"3-component-plastic-scissors","status":"publish","type":"case","link":"https:\/\/tetravision.be\/en\/case\/3-component-plastic-scissors\/","title":{"rendered":"3-Component Plastic Scissors"},"content":{"rendered":"\n<p>Going through some old plastic samples which I collected in the past, I bumped into an interesting product: a&nbsp;<strong>3-component plastic scissors<\/strong>. Where the 3 different materials are&nbsp;<strong>co-injected at the same time<\/strong>, with the hinge installed by&nbsp;<strong>in-mold-assembly techniques<\/strong>. (At least that\u2019s what the packaging tells me.)<\/p>\n\n\n\n<p>This triggered me enough to put the model into our CT-scanner and examine it in a bit more detail. Below you can see some results of the scan.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/In-mold-assembly.avif\"><img fetchpriority=\"high\" decoding=\"async\" width=\"1024\" height=\"812\" src=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/In-mold-assembly-1024x812.avif\" alt=\"\" class=\"wp-image-1893\" srcset=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/In-mold-assembly-1024x812.avif 1024w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/In-mold-assembly-300x238.avif 300w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/In-mold-assembly-768x609.avif 768w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/In-mold-assembly-650x516.avif 650w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/In-mold-assembly.avif 1123w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">What is in-mold assembly?<\/h3>\n\n\n\n<p>Als known as&nbsp;<strong>integrated injection molding<\/strong>, it is a manufacturing process where&nbsp;<strong>pre-fabricated parts<\/strong>&nbsp;are&nbsp;<strong>inserted<\/strong>&nbsp;into a mold cavity&nbsp;<strong>and<\/strong>&nbsp;then&nbsp;<strong>overmolded or encapsulated<\/strong>&nbsp;during the molding process.<\/p>\n\n\n\n<p>This&nbsp;<strong>eliminates post-molding assembly<\/strong>&nbsp;and&nbsp;<strong>reduces part count<\/strong>, leading to&nbsp;<strong>improved product quality and efficiency.<\/strong><\/p>\n\n\n\n<p><strong>Principle:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Tooling acts as an assembly fixture<\/strong>, holding previously molded parts during subsequent molding stages.<\/li>\n\n\n\n<li>Special technology for in-mold assembly (IMA) is found in the tooling, rather then in the molding press.<\/li>\n\n\n\n<li>In some cases\u00a0<strong>rotating or sliding plates<\/strong>\u00a0are used to change cavity configurations between shots.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Benefits<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Reduced part count:<\/strong>\u00a0In-mold assembly eliminates the need for separate assembly operations and reduces the numbers of parts required, leading to a more streamlined and cost-effective process.<\/li>\n<\/ul>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Improved product quality:<\/strong>\u00a0The assembly is performed within the mold, resulting in a more consistent and robust component.<\/li>\n<\/ul>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Increased productivity:<\/strong>\u00a0Eliminating assembly operations and reducing the need for separate presses and molds leads to higher productivity and reduced labor and floor space requirements.<\/li>\n<\/ul>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Faster production:<\/strong>\u00a0In-mold assembly reduces the total time to produce and assemble.<\/li>\n<\/ul>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Enhanced functionality:<\/strong>\u00a0This approach allows for the creation of parts with features that would be difficult or impossible to produce through conventional assembly processes.<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/IMG_3224-rotated-1.avif\"><img decoding=\"async\" width=\"480\" height=\"640\" src=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/IMG_3224-rotated-1.avif\" alt=\"\" class=\"wp-image-1901\" srcset=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/IMG_3224-rotated-1.avif 480w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/IMG_3224-rotated-1-225x300.avif 225w\" sizes=\"(max-width: 480px) 100vw, 480px\" \/><\/a><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Examples<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Articulated joints:<\/strong>\u00a0In-mold assembly can be used to create plastic products with articulated joints by first molding the hole and then molding the pin inside the hole.<\/li>\n<\/ul>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Multi-shot molding:<\/strong>\u00a0In-mold assembly is often used in multi-shot molding where multiple layers of material are applied during the molding process.<\/li>\n<\/ul>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Electronics encapsulation:<\/strong>\u00a0In-mold assembly can be used to encapsulate electronic components within a plastic housing.<\/li>\n<\/ul>\n\n\n\n<p>In-mold assembly is distinct from general multi-shot molding or hard\/soft overmolding, as the<strong>\u00a0core concept is assembling separate components inside the mold<\/strong>\u00a0that would otherwise be assembled outside the mold through methods like snap-fits, welding or adhesive bounding.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"1024\" height=\"683\" src=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/ChatGPT-Image-Apr-16-2025-03_12_18-PM-1024x683.avif\" alt=\"\" class=\"wp-image-1902\" srcset=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/ChatGPT-Image-Apr-16-2025-03_12_18-PM-1024x683.avif 1024w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/ChatGPT-Image-Apr-16-2025-03_12_18-PM-300x200.avif 300w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/ChatGPT-Image-Apr-16-2025-03_12_18-PM-768x512.avif 768w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/ChatGPT-Image-Apr-16-2025-03_12_18-PM-650x433.avif 650w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/ChatGPT-Image-Apr-16-2025-03_12_18-PM.avif 1536w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Benefits of CT-scanning<\/h3>\n\n\n\n<p><strong>Interal assembly verification<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Correct placement\/alignment<\/strong>\u00a0of subcomponents that are assembled within the mold.<\/li>\n\n\n\n<li>Ensures\u00a0<strong>mechanical interlocks or snapt-fits<\/strong>\u00a0formed during molding are engaged properly.<\/li>\n\n\n\n<li>Identifies\u00a0<strong>shifting or rotation<\/strong>\u00a0of parts during overmolding.<\/li>\n<\/ul>\n\n\n\n<p><strong>Bonding and weld quality<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Checks the\u00a0<strong>interfaces<\/strong>\u00a0between the different material layers.<\/li>\n\n\n\n<li>Can reveal\u00a0<strong>lack of adhesion, cold weld or voids<\/strong>\u00a0between overmolded sections.<\/li>\n\n\n\n<li>useful for\u00a0<strong>TPE-over-hard plastic<\/strong>\u00a0combinations where adhesion quality is critical.<\/li>\n<\/ul>\n\n\n\n<p><strong>Void detection<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Internal\u00a0<strong>air pockets<\/strong>\u00a0<strong>or bubble<\/strong>s trapped during molding.<\/li>\n\n\n\n<li>Especially relevant in\u00a0<strong>high-stress zones<\/strong>\u00a0or tight tolerances areas.<\/li>\n\n\n\n<li>Can also identify voids at the<strong>\u00a0interface between molded parts and inserts.<\/strong><\/li>\n<\/ul>\n\n\n\n<p><strong>Cracks and microstructural defects<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Detect\u00a0<strong>micro-cracks, delamination\u00a0<\/strong>or<strong>\u00a0resin-rich\/resin-starved areas.<\/strong><\/li>\n\n\n\n<li>Useful for brittle materials or parts with\u00a0<strong>glass\/mineral fillers.<\/strong><\/li>\n<\/ul>\n\n\n\n<p><strong>Material flow analysis<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Reveals\u00a0<strong>flow lines<\/strong>, knit lines and swirl patterns that may indicate\u00a0<strong>improper gating, poor temperature control<\/strong>\u00a0or\u00a0<strong>material incompatibility.<\/strong><\/li>\n<\/ul>\n\n\n\n<p><strong>Insert placement analysis<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Verifies position and orientation of embedded\u00a0<strong>metal or plastic inserts.<\/strong><\/li>\n\n\n\n<li>Ensures\u00a0<strong>no shift<\/strong>\u00a0<strong>due to injection pressure<\/strong>\u00a0during subsequent molding stages.<\/li>\n<\/ul>\n\n\n\n<p><strong>Wall thickness &amp; dimensional consistency<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Precise measurement of\u00a0<strong>internal and external wall thickness.<\/strong><\/li>\n\n\n\n<li>Cross-sectional analysis to check for\u00a0<strong>warping, sink marks<\/strong>\u00a0or\u00a0<strong>overpacking<\/strong>.<\/li>\n<\/ul>\n\n\n\n<p><strong>Contamination or foreign materials<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Identifies\u00a0<strong>unwanted particles<\/strong>, trapped fibers or\u00a0<strong>non-melted pellets.<\/strong><\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-gallery has-nested-images columns-default is-cropped wp-block-gallery-1 is-layout-flex wp-block-gallery-is-layout-flex\">\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities3.avif\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"498\" data-id=\"1903\" src=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities3-1024x498.avif\" alt=\"\" class=\"wp-image-1903\" srcset=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities3-1024x498.avif 1024w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities3-300x146.avif 300w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities3-768x374.avif 768w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities3-1536x748.avif 1536w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities3-650x316.avif 650w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities3.avif 1808w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities.avif\"><img loading=\"lazy\" decoding=\"async\" width=\"898\" height=\"407\" data-id=\"1904\" src=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities.avif\" alt=\"\" class=\"wp-image-1904\" srcset=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities.avif 898w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities-300x136.avif 300w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities-768x348.avif 768w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities-650x295.avif 650w\" sizes=\"(max-width: 898px) 100vw, 898px\" \/><\/a><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities2.avif\"><img loading=\"lazy\" decoding=\"async\" width=\"875\" height=\"392\" data-id=\"1905\" src=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities2.avif\" alt=\"\" class=\"wp-image-1905\" srcset=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities2.avif 875w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities2-300x134.avif 300w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities2-768x344.avif 768w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/internal-cavities2-650x291.avif 650w\" sizes=\"(max-width: 875px) 100vw, 875px\" \/><\/a><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/section-4.avif\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"434\" data-id=\"1906\" src=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/section-4-1024x434.avif\" alt=\"\" class=\"wp-image-1906\" srcset=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/section-4-1024x434.avif 1024w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/section-4-300x127.avif 300w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/section-4-768x326.avif 768w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/section-4-1536x651.avif 1536w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/section-4-650x276.avif 650w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/section-4.avif 1573w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/touching-blades.avif\"><img loading=\"lazy\" decoding=\"async\" width=\"882\" height=\"512\" data-id=\"1907\" src=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/touching-blades.avif\" alt=\"\" class=\"wp-image-1907\" srcset=\"https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/touching-blades.avif 882w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/touching-blades-300x174.avif 300w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/touching-blades-768x446.avif 768w, https:\/\/tetravision.be\/wp-content\/uploads\/2025\/04\/touching-blades-650x377.avif 650w\" sizes=\"(max-width: 882px) 100vw, 882px\" \/><\/a><\/figure>\n<\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Going through some old plastic samples which I collected in the past, I bumped into an interesting product: a&nbsp;3-component plastic scissors. Where the 3 different materials are&nbsp;co-injected at the same time, with the hinge installed by&nbsp;in-mold-assembly techniques. (At least that\u2019s what the packaging tells me.) This triggered me enough to put the model into our [&hellip;]<\/p>\n","protected":false},"featured_media":2913,"template":"","meta":{"_acf_changed":false},"case-categorie":[20],"class_list":["post-2912","case","type-case","status-publish","has-post-thumbnail","hentry","case-categorie-xray-ct-scanning-en"],"acf":[],"_links":{"self":[{"href":"https:\/\/tetravision.be\/en\/wp-json\/wp\/v2\/case\/2912","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tetravision.be\/en\/wp-json\/wp\/v2\/case"}],"about":[{"href":"https:\/\/tetravision.be\/en\/wp-json\/wp\/v2\/types\/case"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/tetravision.be\/en\/wp-json\/wp\/v2\/media\/2913"}],"wp:attachment":[{"href":"https:\/\/tetravision.be\/en\/wp-json\/wp\/v2\/media?parent=2912"}],"wp:term":[{"taxonomy":"case-categorie","embeddable":true,"href":"https:\/\/tetravision.be\/en\/wp-json\/wp\/v2\/case-categorie?post=2912"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}