{"id":1289,"date":"2023-11-29T02:56:52","date_gmt":"2023-11-28T17:56:52","guid":{"rendered":"https:\/\/www.durastream.com\/en\/ja\/?page_id=1289"},"modified":"2025-12-11T16:45:50","modified_gmt":"2025-12-11T07:45:50","slug":"cpvc-vs-pvc-processing","status":"publish","type":"page","link":"https:\/\/www.durastream.com\/en\/support\/cpvc-vs-pvc-processing\/","title":{"rendered":"CPVC molding processes"},"content":{"rendered":"<div  class=\"frame pt-0 pb-0\">\r\n\t\t<div class=\"hero-flame-single\" style=\"background-image:url(https:\/\/www.durastream.com\/en\/wp-content\/uploads\/sites\/5\/2023\/12\/general-hero1.jpg);\">\r\n\t\t\t<div class=\"hero-flame-single-filter\">\r\n\t\t\t\t<div class=\"hero-title container\">\r\n\t\t\t\t\t\tCPVC molding processes &#8211; Differences from PVC\t\t\t\t<\/div>\r\n\t\t\t<\/div>\r\n\t\t<\/div>\r\n<\/div>\n\n<div  class=\"frame pt-3 pb-0\">\r\n\t<div class=\"container\">\r\n    \t<\/div>\r\n<\/div>\n\n<div  class=\" spacer spacer-m\"><\/div>\r\n\n\n<div class=\"container\">\r\n\t\n\n<p>While comparing it to the PVC molding process, we will introduce the points to note when molding CPVC (extrusion molding, injection molding, profile extrusion molding) and the recommended settings for the molding machine.<\/p>\n\n\n<h2  class=\"title-l2\"><span>Can PVC molding machines be used for CPVC molding?<\/span><\/h2>\r\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-28f84493 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:66.66%\">\n<p>The molding processes for CPVC and PVC are very similar.<\/p>\n\n\n\n<p>CPVC molding processes such as extrusion and injection molding can generally use equipment and tools for PVC molding.<\/p>\n\n\n\n<p>However, it is necessary to set the molding machine appropriately, such as by setting the temperature and screw to match the material characteristics.<\/p>\n\n\n\n<p>The Sekisui Chemical Group is itself a molding manufacturer and has high technological capabilities in the field of molding, including extrusion and injection molding.<br>In addition to selling CPVC compounds, we can also offer process proposals based on our knowledge as a molding manufacturer.<\/p>\n\n\n\n<p>\u3000\u3000<a href=\"https:\/\/www.durastream.com\/en\/products\/technology\/\">For related pages on SEKISUI\u2019s Technology, click here<\/a><\/p>\n\n\n<div  class=\" spacer spacer-s\"><\/div>\r\n\n\n\n<iframe loading=\"lazy\" width=\"560\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/Fxug2JmwvTw?loop=1&amp;playlist=Fxug2JmwvTw\" title=\"SEKISUI Chemical has Decades of Experience in Extruder Diagnosis\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen=\"\"><\/iframe>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:33.33%\">\n<p class=\"has-text-align-center\">CPVC Compound (powder, pellet)<\/p>\n\n\n\r\n<div  class=\"image-block justify-content-center\">\r\n\t<figure>\r\n\t\t<img decoding=\"async\" src=\"https:\/\/www.durastream.com\/en\/wp-content\/uploads\/sites\/5\/2024\/06\/\u2605\u30b3\u30f3\u30d1\u30a6\u30f3\u30c94\u7a2e\u753b\u50cf.png\" alt=\"\">\r\n\t\t\t<\/figure>\r\n<\/div>\n\n\r\n<div  class=\"image-block justify-content-center\">\r\n\t<figure>\r\n\t\t<img decoding=\"async\" src=\"https:\/\/www.durastream.com\/en\/wp-content\/uploads\/sites\/5\/2024\/06\/\u77e2\u5370\u753b\u50cf-e1719447757846.png\" alt=\"\">\r\n\t\t\t<\/figure>\r\n<\/div>\n\n\n<p class=\"has-text-align-center\">Molding (Photo: Extrusion molding)<\/p>\n\n\n\r\n<div  class=\"image-block justify-content-center\">\r\n\t<figure>\r\n\t\t<img decoding=\"async\" src=\"https:\/\/www.durastream.com\/en\/wp-content\/uploads\/sites\/5\/2024\/06\/\u30d1\u30a4\u30d7\u6210\u5f62\u5199\u771f-\u8abf\u6574-1-e1719447996126.png\" alt=\"\">\r\n\t\t\t<\/figure>\r\n<\/div>\n\n\r\n<div  class=\"image-block justify-content-center\">\r\n\t<figure>\r\n\t\t<img decoding=\"async\" src=\"https:\/\/www.durastream.com\/en\/wp-content\/uploads\/sites\/5\/2024\/06\/\u77e2\u5370\u753b\u50cf-e1719447757846.png\" alt=\"\">\r\n\t\t\t<\/figure>\r\n<\/div>\n\n\n<p class=\"has-text-align-center\">Molded product (pipes, etc.)<\/p>\n\n\n\r\n<div  class=\"image-block justify-content-center\">\r\n\t<figure>\r\n\t\t<img decoding=\"async\" src=\"https:\/\/www.durastream.com\/en\/wp-content\/uploads\/sites\/5\/2023\/12\/History-of-CPVC-Business-at-SEKISUI12.jpeg\" alt=\"CPVC pipes\">\r\n\t\t\t<\/figure>\r\n<\/div><\/div>\n<\/div>\n\n\n<div  class=\" spacer spacer-m\"><\/div>\r\n\n\n<h2  class=\"title-l2\"><span>What Is the Main Difference Between CPVC and PVC Processing?<\/span><\/h2>\r\n\n\n\n<p>The main differences between PVC and CPVC are thermal stability and viscosity.<\/p>\n\n\n<div  class=\" spacer spacer-s\"><\/div>\r\n\n\n<h3  class=\"text-left title-l3 \">Thermal stability<\/h3>\n\n<div  class=\"col2-wrapper  customcol-items-start\">\r\n\t\t\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-28f84493 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p>CPVC will not melt without the application of moderate heat and will not exhibit excellent physical properties.<br>On the other hand, it will decompose if exposed to excessively high temperatures. <\/p>\n\n\n\n<p>The diagram on the right is a reference material that shows the crystallization melting points of PVC and CPVC.<\/p>\n\n\n<div  class=\" spacer spacer-\"><\/div>\r\n\n\n<h4  class=\"text-left title-l4 \"><span>Key Points<\/span><\/h4>\n\n\n<p>PVC and CPVC materials have different thermal stabilities:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The residence time of CPVC in the molding machine must be as short as possible.<\/li>\n\n\n\n<li>Temperature setting is important to ensure melting and gelling of the material.<\/li>\n<\/ul>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\r\n<div  class=\"image-block justify-content-center\">\r\n\t<figure>\r\n\t\t<img decoding=\"async\" src=\"https:\/\/www.durastream.com\/en\/wp-content\/uploads\/sites\/5\/2023\/12\/CPVC-vs-PVC-Processing-Differences1.jpeg\" alt=\"CPVC-vs-PVC-Processing-Differences1\">\r\n\t\t\t\t<figcaption class=\"text-center\">This is a reference document and does not guarantee the content.<\/figcaption>\r\n\t\t\t<\/figure>\r\n<\/div><\/div>\n<\/div>\n\n<\/div>\r\n\n\n<div  class=\" spacer spacer-s\"><\/div>\r\n\n\n<h3  class=\"text-left title-l3 \">Viscosity (Fluidity)<\/h3>\n\n\n<p>In general, the viscosity of CPVC is higher than that of PVC. In the case of PVC, the viscosity (=K-value) is set simply by the degree of polymerisation. In the case of CPVC, on the other hand, the viscosity (=K-value) is set by a combination of degree of polymerisation and chlorination.<\/p>\n\n\n<h4  class=\"text-left title-l4 \"><span>Key Points<\/span><\/h4>\n\n\n<ul class=\"wp-block-list\">\n<li>Loads on motors, back pressure.<\/li>\n<\/ul>\n\n\n\n<p>PVC and CPVC materials have different thermal stabilities:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Screw \/ Mold shape<\/li>\n<\/ul>\n\n\n\n<p>The structure of the screw and mould tools is an important factor. Molding equipment must be suitable for CPVC molding.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Attention to shear heating<\/li>\n<\/ul>\n\n\n\n<p>The screw undergoes shear heating. Temperature control is therefore required to keep the material at the correct temperature.<\/p>\n\n\n<div  class=\" spacer spacer-m\"><\/div>\r\n\n\n<h2  class=\"title-l2\"><span>Differences in molding processes (CPVC vs. PVC)<\/span><\/h2>\r\n\n\n<div  class=\" spacer spacer-m\"><\/div>\r\n\n\n<h3  class=\"text-center title-l3 \">Extrusion molding<\/h3>\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><\/td><td>PVC<\/td><td>CPVC<\/td><\/tr><tr><td>Twin-screw extruder<\/td><td>Screw motor\uff1aHigh torque<br>Screw\uff1aParallel\u3000\u03c660-170<br>\u3000\u3000\u3000 Conical\u3000\u03c650-85<\/td><td>Screw mortar\uff1aHigh torque<br>Screw\uff1aParallel\u3000\u03c660-135<br>\u3000\u3000\u3000 Conical\u3000\u03c650-70<\/td><\/tr><tr><td>Screw rotation<\/td><td>\u30fc<\/td><td>Lower than PVC<\/td><\/tr><tr><td>Condition (Barrel Temp.)<\/td><td>300 \u2013 340\u2109<\/td><td>340 \u2013 410\u2109<\/td><\/tr><tr><td>Mold type<\/td><td>Stainless steel<\/td><td>Stainless steel<br>Small quantity (flow channel section)<br>Mold angle: acute angle<\/td><\/tr><\/tbody><\/table><figcaption class=\"wp-element-caption\">*We cannot guarantee these reference values.<\/figcaption><\/figure>\n\n\n<div  class=\" spacer spacer-m\"><\/div>\r\n\n\n<h3  class=\"text-center title-l3 \">Injection molding<\/h3>\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><\/td><td>PVC<\/td><td>CPVC<\/td><\/tr><tr><td>Injection machine<\/td><td>Screw mortar: High torque<br>Barrel cooling: Blower<\/td><td>Screw mortar: High torque<br>Barrel cooling: Blower<br>Barrel zone: 4-5 zone<br>Nozzle: Short nozzle\u3001\u03c6\uff1aLarger than PVC<\/td><\/tr><tr><td>Screw rotation<\/td><td>9-14 m\/sec<\/td><td>8-13 m\/sec<br>(lower than PVC)<\/td><\/tr><tr><td>Condition (Barrel Temp.)<\/td><td>320 \u2013 365\u2109<\/td><td>320 \u2013 392\u2109<\/td><\/tr><tr><td>Condition (holding pressure)<\/td><td>100 \u2013 170 MPa<\/td><td>100 \u2013 170 MPa<\/td><\/tr><tr><td>Mold type<\/td><td>Stainless steel<br>Gate: Direct gate<\/td><td>Stainless steel<br>Gate: Direct gate<\/td><\/tr><\/tbody><\/table><figcaption class=\"wp-element-caption\">*We cannot guarantee these reference values.<\/figcaption><\/figure>\n\n\n<div  class=\" spacer spacer-m\"><\/div>\r\n\n\n<h3  class=\"text-center title-l3 \">Deformed extrusion molding<\/h3>\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><tbody><tr><td><\/td><td>PVC<\/td><td>CPVC<\/td><\/tr><tr><td>Single screw extruder<\/td><td>Single screw machine<br>Screw: Dulmage, Fullfight<\/td><td>Single screw machine<br>Screw: Fullfight recommended (Dulmage)<br>L\/D = 22 \u2013 25<br>Compression ratio: 2.5 \u2013 3.2<\/td><\/tr><tr><td>Screw rotation<\/td><td>15~ rpm (65 mm single)<\/td><td>15\u201325 rpm (65 mm single)<\/td><\/tr><tr><td>Condition (Barrel Temp.)<\/td><td>284 \u2013 338\u2109<\/td><td>300 \u2013 370\u2109<\/td><\/tr><tr><td>Mold type<\/td><td>Stainless steel<\/td><td>Stainless steel<\/td><\/tr><\/tbody><\/table><figcaption class=\"wp-element-caption\">*We cannot guarantee these reference values.<\/figcaption><\/figure>\n\n\n<div  class=\" spacer spacer-m\"><\/div>\r\n\n\n<div  class=\"quote-box\">\r\n\t<h3 class=\"quote-box-title\">Contact<\/h3>\r\n\t<p class=\"quote-box-text text-center\">Click here for product inquiries and sample requests.<\/p>\r\n\t<div class=\"text-center\"><a href=\"\/en\/contact\/\"><button class=\"btn btn-arrow-right hovergradient freetext size-m\"><span>Contact<\/span><\/button><\/a><\/div>\r\n<\/div>\n\n<div  class=\" spacer spacer-m\"><\/div>\r\n\n<\/div>\r\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":2,"featured_media":0,"parent":254,"menu_order":37,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-1289","page","type-page","status-publish","hentry"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.durastream.com\/en\/wp-json\/wp\/v2\/pages\/1289","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.durastream.com\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.durastream.com\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.durastream.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.durastream.com\/en\/wp-json\/wp\/v2\/comments?post=1289"}],"version-history":[{"count":42,"href":"https:\/\/www.durastream.com\/en\/wp-json\/wp\/v2\/pages\/1289\/revisions"}],"predecessor-version":[{"id":3402,"href":"https:\/\/www.durastream.com\/en\/wp-json\/wp\/v2\/pages\/1289\/revisions\/3402"}],"up":[{"embeddable":true,"href":"https:\/\/www.durastream.com\/en\/wp-json\/wp\/v2\/pages\/254"}],"wp:attachment":[{"href":"https:\/\/www.durastream.com\/en\/wp-json\/wp\/v2\/media?parent=1289"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}