{"id":453,"date":"2025-11-14T12:51:10","date_gmt":"2025-11-14T03:51:10","guid":{"rendered":"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/?p=453"},"modified":"2025-11-14T16:52:10","modified_gmt":"2025-11-14T07:52:10","slug":"feedneck","status":"publish","type":"post","link":"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/en\/knowledge\/feedneck.html","title":{"rendered":"Feed bottlenecks occurring with low bulk density raw materials"},"content":{"rendered":"<p>\n      When processing raw materials with low bulk density in an extruder<span class=\"marker\">Feedneck challenges, problems with conventional extruders, and extruders that solve them.<\/span>This section describes the following\n    <\/p>\n<\/header>\n<p>  <main><\/p>\n<div id=\"intro\">\n<h2>What you will find on this page<\/h2>\n<ul>\n<li>Feed bottleneck issues that occur with low bulk density raw materials<\/li>\n<li>Challenges of conventional extruders<\/li>\n<li>Extruder that solves feed neck problems<\/li>\n<\/ul>\n<p>\n        One of the most troublesome phenomena when processing low bulk density materials in an extruder is \"feed necking. This is<span class=\"marker\">The air held in the material is not discharged sufficiently in the extruder, resulting in poor material penetration and clogging of the material in the extruder's material hopper.<\/span>refers to\n      <\/p>\n<p>\n        When feed bottlenecks occur, not only does the supply of raw materials become unstable, but it can also lead to serious problems such as lower throughput and variations in product quality. Solving this problem has become an unavoidable priority for manufacturing sites, especially as the demand for environmentally friendly and recycled materials increases.\n      <\/p>\n<\/p><\/div>\n<div id=\"materials\">\n<h2>Examples of materials with low bulk density<\/h2>\n<h3>Recycled raw materials<\/h3>\n<figure>\n      <img decoding=\"async\" src=\"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/wp\/wp-content\/uploads\/film.png\" alt=\"Imaged figure of PET film\" \/><figcaption>PET film<\/figcaption><\/figure>\n<ul>\n<li>Various resin fiber crushed products<\/li>\n<li>Crushed PET films and sheets, etc.<\/li>\n<\/ul>\n<h3>Inorganic filler<\/h3>\n<div class=\"image-wrap\">\n<figure>\n      <img decoding=\"async\" src=\"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/wp\/wp-content\/uploads\/calcium-carbonate.png\" alt=\"Imaged figure of calcium carbonate\" \/><figcaption>calcium carbonate (CaCO3) powder<\/figcaption><\/figure>\n<figure>\n      <img decoding=\"async\" src=\"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/wp\/wp-content\/uploads\/mica.jpg\" alt=\"Image of mica\" \/><figcaption>mica<\/figcaption><\/figure>\n<\/div>\n<ul>\n<li>fine talcum powder<\/li>\n<li>calcium carbonate (CaCO3) powder<\/li>\n<li>Mica, etc.<\/li>\n<\/ul>\n<h3>Organic filler<\/h3>\n<div class=\"image-wrap\">\n<figure>\n      <img decoding=\"async\" src=\"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/wp\/wp-content\/uploads\/wood-flour.png\" alt=\"Image of wood flour\" \/><figcaption>wood flour<\/figcaption><\/figure>\n<figure>\n      <img decoding=\"async\" src=\"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/wp\/wp-content\/uploads\/cellulose-nanofiber.png\" alt=\"Image of cellulose nanofiber\" \/><figcaption>cellulose nanofiber<\/figcaption><\/figure>\n<\/div>\n<ul>\n<li>wood flour<\/li>\n<li>cellulose fiber<\/li>\n<li>Carbon fiber, etc.<\/li>\n<\/ul><\/div>\n<div id=\"legacy-extruder\">\n<h2>Limitations of conventional twin-screw extruders<\/h2>\n<p>\n        Conventional twin-screw extruders of the meshing and co-directional rotation type have a structural limitation: the two screws rotate in the same direction while meshing,<span class=\"marker\">Fatal drawback of almost no clearance between screws, blocking gas escape path<\/span>We are having a\n      <\/p>\n<p>\n        Furthermore, kneading discs used for kneading generate a large amount of heat because they continuously apply a strong shear force under high speed rotation and high compression conditions.\n      <\/p>\n<p>\n        Since raw materials with lower bulk density contain more air, the kneading disc in such a structure blocks gas and air, causing them to flow back at the material supply section. As a result, stable continuous operation becomes difficult, resulting in a significant decrease in production efficiency.\n      <\/p>\n<div class=\"low-center-img\">\n        <img decoding=\"async\"  src=\"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/wp\/wp-content\/uploads\/intermeshing_en.png\" alt=\"Twin-screw extruder in the same direction\">\n      <\/div>\n<\/p><\/div>\n<div id=\"htm-intro\">\n<h2>Introducing an extruder with excellent degassing properties<\/h2>\n<h3>C.T.E.'s HTM twin-screw extruder<\/h3>\n<div class=\"onb-center-img\">\n        <img decoding=\"async\" src=\"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/wp\/wp-content\/themes\/sd-1\/img\/product_htm.jpg\" alt=\"HTM Twin-Screw Kneading Extruder\"><\/p>\n<div class=\"caption\">*Image taken from: CTE's official website (<a href=\"https:\/\/cte-japan.com\/en\/product\/htm-twin-screw-extruder\/\" target=\"_blank\">https:\/\/cte-japan.com\/en\/product\/htm-twin-screw-extruder\/<\/a>)<\/div>\n<\/p><\/div>\n<p>\n        An innovative solution to these challenges is CTE's HTM twin-screw extruder. This equipment is<span class=\"marker\">Unique structure of \"interdirectional rotation and non-intermeshing type<\/span>The company has adopted the following\n      <\/p>\n<p>\n        The most distinctive feature of the HTM is that the two screws do not engage each other but rotate in opposite directions. Since an adequate space is secured between the screws, gas can escape smoothly, resulting in excellent degassing performance.\n      <\/p>\n<p>\n        In addition, since kneading is performed in the rotor element, instantaneous high shear is achieved, but shear and compression are immediately released, thus minimizing heat generation.\n      <\/p>\n<p>\n        Furthermore, the rear vent system in the material feed section fundamentally prevents feed necks even with low bulk density materials. This structure improves the feed neck and enables a higher discharge rate compared to conventional extruders.\n      <\/p>\n<\/p><\/div>\n<div id=\"htm-solutions\">\n<h2>Extruder problems solved by the HTM twin-screw extruder<\/h2>\n<p>\n        It is not only the feed-neck phenomenon that HTM solves.<span class=\"marker\">The following problems are likely to occur in the extrusion process<\/span>The system can also be used for\n      <\/p>\n<article id=\"resin-degradation\">\n<h3>Resin degradation<\/h3>\n<p>\n          HTM tandem extruders are<span class=\"marker\">Structure that effectively suppresses shear heating in the kneading section and enables independent temperature control in the subsequent single-axis extrusion section<\/span>The temperature of the machine is set at a low level. This feature allows for both excellent dispersion and high output while maintaining a low actual operating temperature.\n        <\/p>\n<p>\n          The tandem configuration also allows independent control of the speed of the single-shaft section, enabling extrusion at lower temperatures and lower shear, making it ideal for processing heat-sensitive biomass resins and biodegradable resins.\n        <\/p>\n<h4>Key Points to Control Resin Deterioration<\/h4>\n<ol>\n<li>\n            <strong>Kneading by Rotor<\/strong><br \/>\n            Kneading with a rotor causes instantaneous compression and shear, followed by release and repetition of the process, resulting in low heat generation.\n          <\/li>\n<li>\n            <strong>tandem-type<\/strong><br \/>\n            Since the single-shaft section is independent, the temperature and screw speed can be lowered, thereby reducing shear heating in the extrusion section.\n          <\/li>\n<\/ol>\n<\/article>\n<article id=\"dispersion\">\n<h3>dispersion failure<\/h3>\n<p>\n          <span class=\"marker\">Unique kneading mechanism created by non-intermeshing structure<\/span>is also powerful for uniform dispersion of filler. Instantaneous high shear by the rotor element and repetitive compression and release result in high shear force but low heat generation.\n        <\/p>\n<p>\n          Even fine filler powder that tends to agglomerate can be dispersed efficiently. This makes it possible to produce compounds with excellent physical properties even with highly concentrated filler blends.\n        <\/p>\n<\/article><\/div>\n<div id=\"summary\">\n<h2>summary<\/h2>\n<p>\n        The feed-neck phenomenon is a major issue for raw materials with small bulk density. This problem is not just a feeding trouble, but an important issue that directly affects productivity and quality.\n      <\/p>\n<p>\n        C-TE's HTM twin-screw extruder provides a solution to this challenge through its innovative design of interdirectional rotation and non-intermeshing structure.<span class=\"marker\">Superior degassing performance prevents feed necks, while at the same time inhibiting resin degradation and improving dispersion.<\/span>.\n      <\/p>\n<p>\n        If you feel the limitations of conventional machines, why not consider introducing HTM? We also accept free introduction tests, so please feel free to consult us using the form below.\n      <\/p>\n<p class=\"btn-web\">\n        <a href=\"https:\/\/cte-japan.com\/en\/contact\/\" target=\"_blank\" rel=\"noopener noreferrer\"><br \/>\n          Click here for introduction test and consultation form<br \/>\n        <\/a>\n      <\/p>\n<\/p><\/div>","protected":false},"excerpt":{"rendered":"<p>This page explains the challenges of feed necks when processing low bulk density raw materials with an extruder, the problems with conventional extruders, and the extruders that solve these problems. What You Will Find on This Page Feed Neck Issues Occurring with Low Bulk Density Raw Materials Conventional Extruders [...].<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[7],"tags":[],"class_list":["post-453","post","type-post","status-publish","format-standard","hentry","category-knowledge"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/en\/wp-json\/wp\/v2\/posts\/453","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/en\/wp-json\/wp\/v2\/comments?post=453"}],"version-history":[{"count":4,"href":"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/en\/wp-json\/wp\/v2\/posts\/453\/revisions"}],"predecessor-version":[{"id":464,"href":"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/en\/wp-json\/wp\/v2\/posts\/453\/revisions\/464"}],"wp:attachment":[{"href":"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/en\/wp-json\/wp\/v2\/media?parent=453"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/en\/wp-json\/wp\/v2\/categories?post=453"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.pla-mirai.net\/twinscrew-extruder\/en\/wp-json\/wp\/v2\/tags?post=453"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}