{"id":12592,"date":"2026-05-09T08:27:51","date_gmt":"2026-05-09T08:27:51","guid":{"rendered":"https:\/\/ideal-pro.com\/?p=12592"},"modified":"2026-05-09T08:54:48","modified_gmt":"2026-05-09T08:54:48","slug":"why-is-my-abs-injection-part-dull-troubleshooting-low-gloss","status":"publish","type":"post","link":"https:\/\/ideal-pro.com\/ja\/why-is-my-abs-injection-part-dull-troubleshooting-low-gloss\/","title":{"rendered":"Why is My ABS Injection Part Dull? Troubleshooting Low Gloss"},"content":{"rendered":"

Why is My ABS Injection Part Dull? Troubleshooting Low Gloss<\/h1>\n

You have spent hours polishing the mold to a mirror finish, yet the final ABS injection molded parts come out dull or hazy. This is a common frustration in the plastics industry.<\/p>\n

If the mold polishing isn't the issue, the problem likely lies in the \u5c04\u51fa\u6210\u5f62\u30d7\u30ed\u30bb\u30b9<\/strong>, \u91d1\u578b\u8a2d\u8a08<\/strong>, \u3042\u308b\u3044\u306f raw material handling<\/strong>.<\/p>\n

Here is a comprehensive guide to troubleshooting low gloss on ABS parts.<\/p>\n

\n

1. Mold Design & Maintenance Factors<\/h2>\n

Even with a polished cavity, specific design flaws or maintenance issues can ruin the surface finish.<\/p>\n

    \n
  • Poor Cavity Machining:<\/strong> If the mold cavity has microscopic pores, scratches, or excessive roughness from machining, these defects will transfer directly to the plastic part.\n
      \n
    • Solution:<\/strong> Ensure high-precision machining. If necessary, re-polish or apply a chrome plating<\/strong> to the cavity surface.<\/li>\n<\/ul><\/li>\n
    • Cavity Surface Contamination:<\/strong> Oil, water stains, or excessive release agent on the cavity surface will cause the part to appear dark or matte.\n
        \n
      • Solution:<\/strong> Clean the mold thoroughly to remove oil and water. Limit the use of mold release agents.<\/li>\n<\/ul><\/li>\n
      • Insufficient Draft Angle:<\/strong> If the draft angle is too small, the part experiences excessive friction during ejection, damaging the surface gloss.\n
          \n
        • Solution:<\/strong> Increase the draft angle to ensure smooth ejection.<\/li>\n<\/ul><\/li>\n
        • Poor Venting:<\/strong> Trapped air or gas inside the mold cavity prevents the melt from contacting the mold wall perfectly, leading to dull spots.\n
            \n
          • Solution:<\/strong> Inspect and modify the mold venting system.<\/li>\n<\/ul><\/li>\n
          • Improper Gate or Runner Design:<\/strong> If the gate or runner cross-section is too small or changes abruptly, the melt flow becomes turbulent due to high shear stress.\n
              \n
            • Solution:<\/strong> Increase the cross-sectional area of the gate and runner to ensure smooth laminar flow.<\/li>\n<\/ul><\/li>\n<\/ul>\n

              \"Injection<\/p>\n

              \n

              2. Injection Molding Process Parameters<\/h2>\n

              For ABS, temperature and pressure control are critical for replicating the mold's surface finish.<\/p>\n

                \n
              • Injection Speed Too Low:<\/strong> A slow injection speed prevents the melt from packing tightly against the mold wall, resulting in a non-dense surface.\n
                  \n
                • Solution:<\/strong> Appropriately increase the injection speed<\/strong>.<\/li>\n<\/ul><\/li>\n
                • Insufficient Cooling:<\/strong> Especially for thick-walled parts, if cooling is uneven or insufficient, the surface can become rough or \"hairy.\"\n
                    \n
                  • Solution:<\/strong> Optimize the cooling system. Using chilled water<\/strong> can sometimes help achieve a higher gloss.<\/li>\n<\/ul><\/li>\n
                  • Improper Holding Pressure:<\/strong> If holding pressure or time is too short, the part density decreases, leading to poor gloss.\n
                      \n
                    • Solution:<\/strong> Increase holding pressure and extend holding time.<\/li>\n<\/ul><\/li>\n
                    • Melt Temperature Too Low:<\/strong> Low temperatures reduce the fluidity of the ABS, making it difficult to fill the cavity smoothly.\n
                        \n
                      • Solution:<\/strong> Appropriately raise the barrel and melt temperature.<\/li>\n<\/ul><\/li>\n
                      • Speed vs. Gate Size Mismatch:<\/strong> If the injection speed is too high for a small gate, the area near the gate may appear dark or dull due to shear heating.\n
                          \n
                        • Solution:<\/strong> Reduce injection speed or enlarge the gate size.<\/li>\n<\/ul><\/li>\n<\/ul>\n

                          \"Effect<\/p>\n

                          \n

                          3. Raw Material Issues<\/h2>\n

                          The quality of the ABS resin itself plays a massive role in the final appearance.<\/p>\n

                            \n
                          • Inconsistent Granule Size:<\/strong> Large variations in particle size make it difficult to plasticize the material uniformly.\n
                              \n
                            • Solution:<\/strong> Sieve the raw material to ensure consistent granule size.<\/li>\n<\/ul><\/li>\n
                            • Excessive Recycled Material:<\/strong> Adding too much regrind or sprue material affects the homogeneity of the melt.\n
                                \n
                              • Solution:<\/strong> Reduce the percentage of recycled material used.<\/li>\n<\/ul><\/li>\n
                              • Poor Thermal Stability:<\/strong> Some lower-quality materials degrade or discolor when heated, reducing gloss.\n
                                  \n
                                • Solution:<\/strong> Select ABS grades with better thermal stability.<\/li>\n<\/ul><\/li>\n
                                • High Volatile Content:<\/strong> Excessive moisture or volatiles in the raw material will turn into gas during heating, causing condensation marks or dullness.\n
                                    \n
                                  • Solution:<\/strong> Pre-dry the raw material<\/strong> strictly according to specifications.<\/li>\n<\/ul><\/li>\n
                                  • Poor Additive Dispersion:<\/strong> If colorants or additives do not disperse well, the surface will look uneven.\n
                                      \n
                                    • Solution:<\/strong> Switch to additives with better flow and dispersion properties.<\/li>\n<\/ul><\/li>\n
                                    • Contamination:<\/strong> Foreign materials or incompatible plastics mixed in will not melt uniformly.\n
                                        \n
                                      • Solution:<\/strong> Strictly inspect and clean raw materials before use.<\/li>\n<\/ul><\/li>\n
                                      • Insufficient Lubricant:<\/strong> Low lubricant levels reduce melt flow, preventing the surface from becoming dense.\n
                                          \n
                                        • Solution:<\/strong> Appropriately increase the lubricant dosage.<\/li>\n<\/ul><\/li>\n<\/ul>\n

                                          \"Quality<\/p>\n

                                          \n

                                          Summary<\/h2>\n

                                          If your mold polishing is up to standard, troubleshooting low gloss on ABS parts requires a systematic approach.<\/p>\n

                                            \n
                                          1. Check the Mold:<\/strong> Ensure it is clean, vented, and has a sufficient draft angle.<\/li>\n
                                          2. Adjust Process:<\/strong> Try higher mold temperatures<\/strong>, higher injection speeds<\/strong>, \u305d\u3057\u3066 higher pressure<\/strong>.<\/li>\n
                                          3. Verify Material:<\/strong> Ensure the ABS is dry, clean, and of high quality.<\/li>\n<\/ol>\n

                                            \"Why<\/p>\n

                                            By adjusting these variables, you can achieve the high-gloss finish your project requires.<\/p>","protected":false},"excerpt":{"rendered":"

                                            Why is My ABS Injection Part Dull? Troubleshooting Low Gloss You have spent hours polishing the mold to a mirror […]<\/p>\n","protected":false},"author":2,"featured_media":12596,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_seopress_robots_primary_cat":"","_seopress_titles_title":"","_seopress_titles_desc":"Mold polishing is perfect, but your ABS parts are still dull? Discover the hidden causes of low gloss in injection molding, covering mold design, processing parameters, and raw materials.","_seopress_robots_index":"","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":"","ast-disable-related-posts":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"default","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-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-opacity":"","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-opacity":"","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-opacity":"","overlay-gradient":""}},"ast-content-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-opacity":"","overlay-gradient":""},"tablet":{"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-opacity":"","overlay-gradient":""},"mobile":{"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-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[21],"tags":[217,154,218],"class_list":["post-12592","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","tag-abs-injection-molding-gloss","tag-injection-molding-defects","tag-low-gloss-troubleshooting"],"acf":[],"_links":{"self":[{"href":"https:\/\/ideal-pro.com\/ja\/wp-json\/wp\/v2\/posts\/12592","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ideal-pro.com\/ja\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ideal-pro.com\/ja\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ideal-pro.com\/ja\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/ideal-pro.com\/ja\/wp-json\/wp\/v2\/comments?post=12592"}],"version-history":[{"count":3,"href":"https:\/\/ideal-pro.com\/ja\/wp-json\/wp\/v2\/posts\/12592\/revisions"}],"predecessor-version":[{"id":12599,"href":"https:\/\/ideal-pro.com\/ja\/wp-json\/wp\/v2\/posts\/12592\/revisions\/12599"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ideal-pro.com\/ja\/wp-json\/wp\/v2\/media\/12596"}],"wp:attachment":[{"href":"https:\/\/ideal-pro.com\/ja\/wp-json\/wp\/v2\/media?parent=12592"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ideal-pro.com\/ja\/wp-json\/wp\/v2\/categories?post=12592"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ideal-pro.com\/ja\/wp-json\/wp\/v2\/tags?post=12592"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}