{"id":2903,"date":"2026-08-10T10:35:32","date_gmt":"2026-08-10T02:35:32","guid":{"rendered":"http:\/\/0"},"modified":"2026-08-04T17:53:22","modified_gmt":"2026-08-04T09:53:22","slug":"specs-for-injection-molding-surface-finishing-spi-standards","status":"publish","type":"post","link":"https:\/\/www.jcinjectionmolding.com\/de\/blog\/specs-for-injection-molding-surface-finishing-spi-standards\/","title":{"rendered":"Specs for Injection Molding Surface Finishing: SPI Standards"},"content":{"rendered":"<article style=\"font-family: -apple-system, BlinkMacSystemFont, &#039;Segoe UI&#039;, Roboto, Helvetica, Arial, sans-serif;color: #333333;width: 100%\">\n<section style=\"margin-bottom: 30px\">\n<p style=\"font-size: 18px;line-height: 1.8em;text-align: left;margin-bottom: 24px\">Die Verbesserung von \u00c4sthetik, haptischer Ergonomie und elektromagnetischer Leistung von Kunststoff-Hardware erfordert umfassende Nachbearbeitung und Oberfl\u00e4chenbehandlung der Kavit\u00e4t. Standardm\u00e4\u00dfig roh gespritzte Kunststoffteile weisen h\u00e4ufig Flie\u00dflinien, Trennfugen oder Auswerfermarkierungen auf, die die visuelle Qualit\u00e4t beeintr\u00e4chtigen. Die Anwendung spezieller Formtexturen, Diamantspiegelpolitur, leitf\u00e4higer Beschichtungen oder mehrfarbiger Tamponbedruckung verwandelt rohe Polymerteile in marktreife Einzelhandelskomponenten. Dieser technische Leitfaden behandelt SPI-Polierstandards, VDI-Texturierung, sekund\u00e4re Druckverfahren und EMI-\/RFI-Abschirmtechnologien.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2906\" src=\"https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/inspecting-finished-plastic-parts.webp\" alt=\"inspecting-finished-plastic-parts\" width=\"1376\" height=\"768\" srcset=\"https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/inspecting-finished-plastic-parts.webp 1376w, https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/inspecting-finished-plastic-parts-300x167.webp 300w, https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/inspecting-finished-plastic-parts-1024x572.webp 1024w, https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/inspecting-finished-plastic-parts-768x429.webp 768w\" sizes=\"auto, (max-width: 1376px) 100vw, 1376px\" \/><\/p>\n<\/section>\n<p><!-- Table of Contents --><\/p>\n<section style=\"background-color: #f8f9fa;border-left: 4px solid #0056b3;padding: 24px;border-radius: 6px;margin: 40px 0\">\n<h3 style=\"font-size: 22px;font-weight: bold;line-height: 1.5em;margin-top: 0;margin-bottom: 16px;color: #111111\">Inhaltsverzeichnis<\/h3>\n<ul style=\"list-style-type: none;padding-left: 0;margin: 0\">\n<li style=\"margin-bottom: 12px\"><a style=\"color: #0056b3;text-decoration: none;font-size: 17px;font-weight: 500\" href=\"#spi-vdi-finishes\">1. SPI-Formpolitur (A-1-Spiegelfinish) und VDI-\/Mold-Tech-Texturierung<\/a><\/li>\n<li style=\"margin-bottom: 12px\"><a style=\"color: #0056b3;text-decoration: none;font-size: 17px;font-weight: 500\" href=\"#secondary-operations\">2. Sekund\u00e4re Operationen: Tampondruck, Siebdruck, Lasergravur und Lackierung<\/a><\/li>\n<li style=\"margin-bottom: 0\"><a style=\"color: #0056b3;text-decoration: none;font-size: 17px;font-weight: 500\" href=\"#emi-shielding\">3. Leitf\u00e4hige EMI-\/RFI-Abschirmbeschichtungen f\u00fcr elektronische Geh\u00e4use<\/a><\/li>\n<\/ul>\n<\/section>\n<p><!-- Section 1 --><\/p>\n<section id=\"spi-vdi-finishes\" style=\"margin-bottom: 50px\">\n<h2 style=\"font-size: 28px;line-height: 1.5em;font-weight: bold;margin-top: 40px;margin-bottom: 24px;color: #111111;border-bottom: 1px solid #eaeaea;padding-bottom: 8px\">SPI-Formpolitur (A-1-Spiegelfinish) und VDI-\/Mold-Tech-Texturierung<\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2904\" src=\"https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/vdi-mold-cavity-texturing.webp\" alt=\"vdi-mold-cavity-texturing\" width=\"1376\" height=\"768\" srcset=\"https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/vdi-mold-cavity-texturing.webp 1376w, https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/vdi-mold-cavity-texturing-300x167.webp 300w, https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/vdi-mold-cavity-texturing-1024x572.webp 1024w, https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/vdi-mold-cavity-texturing-768x429.webp 768w\" sizes=\"auto, (max-width: 1376px) 100vw, 1376px\" \/><\/p>\n<p style=\"font-size: 18px;line-height: 1.8em;text-align: left;margin-bottom: 24px\">Spezifikation professioneller <a href=\"https:\/\/www.jcinjectionmolding.com\/de\/service\/surface-finishes\/\"><strong>Oberfl\u00e4chenveredelung beim Spritzgie\u00dfen<\/strong><\/a> beginnt bei der Werkzeugherstellung der Formkavit\u00e4t. Die Vorbereitung der Kavit\u00e4tsoberfl\u00e4che folgt den internationalen Polierstandards der Society of the Plastics Industry (SPI). Das Erreichen eines <strong>SPI-A-1-Spiegelfinishs<\/strong> erfordert progressives Handpolieren mit Diamantpasten auf geh\u00e4rtetem <strong>S136-Edelstahl<\/strong>, eliminiert Mikrokratzer f\u00fcr optische Linsen und hochgl\u00e4nzende <strong>Polycarbonat (PC)<\/strong> Abdeckungen. Die Anwendung von <strong>VDI-3400-Texturierung<\/strong> oder <strong>Mold-Tech-Chemisch\u00e4tzen<\/strong> verleiht kontrollierte matte, Leder- oder geometrische Texturen direkt auf den Kavit\u00e4tsfl\u00e4chen der Form. Chemische Texturierung maskiert Flie\u00dflinien und Einfallstellen-Schatten und verbessert gleichzeitig den taktilen Griff bei Geh\u00e4usen der Unterhaltungselektronik.<\/p>\n<p><!-- Numbered List --><\/p>\n<p style=\"font-size: 18px;line-height: 1.8em;text-align: left;margin-bottom: 16px\">Standards f\u00fcr die Oberfl\u00e4chenbearbeitung von Formkavit\u00e4ten umfassen:<\/p>\n<ol style=\"font-size: 18px;line-height: 1.8em;margin-bottom: 24px;padding-left: 24px;list-style-type: decimal\">\n<li style=\"margin-bottom: 12px;text-align: left\"><strong>SPI A-1 Diamantpolitur<\/strong>\u2014Das L\u00e4ppen von geh\u00e4rtetem Stahl mit 3-Mikron-Diamantpaste erzeugt eine hochgl\u00e4nzende optische Spiegelfl\u00e4che.<\/li>\n<li style=\"margin-bottom: 12px;text-align: left\"><strong>VDI-3400-Funkenerosions-Texturierung<\/strong>\u2014Die elektrische Entladungsbearbeitung erzeugt kontrollierte matte Mikrostrukturen von VDI 12 bis VDI 36.<\/li>\n<li style=\"margin-bottom: 12px;text-align: left\"><strong>Mold-Tech-Chemisch\u00e4tzen<\/strong>\u2014S\u00e4ure\u00e4tzen erzeugt komplexe Leder-, Holzmaserungs- oder geometrische Muster direkt auf dem Kavit\u00e4tsstahl.<\/li>\n<li style=\"margin-bottom: 12px;text-align: left\"><strong>Entformungsschr\u00e4gen-Kompensation<\/strong>\u2014Increasing vertical draft by 1\u00b0 for every 0.025 mm of texture depth ensures clean part ejection without scuffing.<\/li>\n<\/ol>\n<\/section>\n<p><!-- Section 2 --><\/p>\n<section id=\"secondary-operations\" style=\"margin-bottom: 50px\">\n<h2 style=\"font-size: 28px;line-height: 1.5em;font-weight: bold;margin-top: 40px;margin-bottom: 24px;color: #111111;border-bottom: 1px solid #eaeaea;padding-bottom: 8px\">Secondary Ops: Pad Printing, Silk Screening, Laser Engraving &amp; Painting<\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2908\" src=\"https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/pad-printing-plastic-housing.webp\" alt=\"pad-printing-plastic-housing\" width=\"1376\" height=\"768\" srcset=\"https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/pad-printing-plastic-housing.webp 1376w, https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/pad-printing-plastic-housing-300x167.webp 300w, https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/pad-printing-plastic-housing-1024x572.webp 1024w, https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/pad-printing-plastic-housing-768x429.webp 768w\" sizes=\"auto, (max-width: 1376px) 100vw, 1376px\" \/><\/p>\n<p style=\"font-size: 18px;line-height: 1.8em;text-align: left;margin-bottom: 24px\">Secondary post-molding operations add functional symbols, branding logos, and protective coatings to molded <strong>ABS<\/strong> oder <a href=\"https:\/\/www.jcinjectionmolding.com\/de\/materials\/abs\/\"><strong>PC\/ABS<\/strong><\/a> parts. Utilizing multi-color <strong>pad printing<\/strong> transfers silicone pad ink onto complex three-dimensional curves and textured surfaces seamlessly. Laser engraving burns away superficial paint coats on backlit buttons, creating precise, light-transmitting symbols. Automated liquid spray painting and UV hard-coat applications improve scratch resistance and chemical immunity on automotive interior trims.<\/p>\n<\/section>\n<p><!-- Section 3 --><\/p>\n<section id=\"emi-shielding\" style=\"margin-bottom: 50px\">\n<h2 style=\"font-size: 28px;line-height: 1.5em;font-weight: bold;margin-top: 40px;margin-bottom: 24px;color: #111111;border-bottom: 1px solid #eaeaea;padding-bottom: 8px\">Conductive EMI\/RFI Shielding Coatings for Electronic Enclosures<\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2905\" src=\"https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/conductive-emi-shielding-coating.webp\" alt=\"conductive-emi-shielding-coating\" width=\"1376\" height=\"768\" srcset=\"https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/conductive-emi-shielding-coating.webp 1376w, https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/conductive-emi-shielding-coating-300x167.webp 300w, https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/conductive-emi-shielding-coating-1024x572.webp 1024w, https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/conductive-emi-shielding-coating-768x429.webp 768w\" sizes=\"auto, (max-width: 1376px) 100vw, 1376px\" \/><\/p>\n<p style=\"font-size: 18px;line-height: 1.8em;text-align: left;margin-bottom: 24px\">Electronic enclosures housing sensitive circuit boards require protection against electromagnetic interference. Applying conductive <strong>EMI\/RFI shielding coatings<\/strong> inside plastic housings prevents stray radio frequency signals from disrupting internal electronics. Specialized spray painting utilizes nickel, copper, or silver conductive paint formulations to form a continuous grounding barrier. Achieving low surface resistance below 0.1 \u03a9\/sq meets global FCC and CE electromagnetic compatibility regulations for medical and aerospace devices.<\/p>\n<p><!-- Table 1: Finishing Comparison Table --><\/p>\n<div style=\"margin: 32px 0\">\n<table style=\"width: 100%;border-collapse: collapse;font-size: 16px;text-align: left;min-width: 600px\">\n<thead>\n<tr style=\"background-color: #f8f9fa;border-bottom: 2px solid #dee2e6\">\n<th style=\"padding: 16px;border: 1px solid #dee2e6;font-weight: 600;color: #111111\">Surface Finishing Method<\/th>\n<th style=\"padding: 16px;border: 1px solid #dee2e6;font-weight: 600;color: #111111\">Roughness \/ Thickness<\/th>\n<th style=\"padding: 16px;border: 1px solid #dee2e6;font-weight: 600;color: #111111\">Compatible Substrate<\/th>\n<th style=\"padding: 16px;border: 1px solid #dee2e6;font-weight: 600;color: #111111\">Primary Aesthetic \/ Functional Benefit<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr style=\"border-bottom: 1px solid #dee2e6\">\n<td style=\"padding: 16px;border: 1px solid #dee2e6;color: #333333\">SPI A-1 Diamond Polish<\/td>\n<td style=\"padding: 16px;border: 1px solid #dee2e6;color: #333333\">Ra &lt; 0.012 \u03bcm<\/td>\n<td style=\"padding: 16px;border: 1px solid #dee2e6;color: #333333\">PC, PMMA, Optical Resins<\/td>\n<td style=\"padding: 16px;border: 1px solid #dee2e6;color: #333333\">High-gloss transparency for optical lenses &amp; light guides<\/td>\n<\/tr>\n<tr style=\"border-bottom: 1px solid #dee2e6\">\n<td style=\"padding: 16px;border: 1px solid #dee2e6;color: #333333\">VDI 24 Spark Texture<\/td>\n<td style=\"padding: 16px;border: 1px solid #dee2e6;color: #333333\">Ra = 1.6 \u03bcm<\/td>\n<td style=\"padding: 16px;border: 1px solid #dee2e6;color: #333333\">ABS, PC\/ABS, PP, PA66<\/td>\n<td style=\"padding: 16px;border: 1px solid #dee2e6;color: #333333\">Matte tactile finish masking sink marks &amp; scratches<\/td>\n<\/tr>\n<tr style=\"border-bottom: 1px solid #dee2e6\">\n<td style=\"padding: 16px;border: 1px solid #dee2e6;color: #333333\">Conductive Nickel Coating<\/td>\n<td style=\"padding: 16px;border: 1px solid #dee2e6;color: #333333\">25 &#8211; 50 \u03bcm dry film<\/td>\n<td style=\"padding: 16px;border: 1px solid #dee2e6;color: #333333\">ABS, PC\/ABS, PBT<\/td>\n<td style=\"padding: 16px;border: 1px solid #dee2e6;color: #333333\">EMI\/RFI shielding (&lt; 0.1 \u03a9\/sq) for electronic housings<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/section>\n<p><!-- FAQ Section --><\/p>\n<section id=\"faq\" style=\"margin-bottom: 40px\">\n<h2 style=\"font-size: 28px;line-height: 1.5em;font-weight: bold;margin-top: 40px;margin-bottom: 24px;color: #111111;border-bottom: 1px solid #eaeaea;padding-bottom: 8px\">Frequently Asked Questions (FAQs)<\/h2>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2907\" src=\"https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/measuring-surface-roughness-ra.webp\" alt=\"measuring-surface-roughness-ra\" width=\"1376\" height=\"768\" srcset=\"https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/measuring-surface-roughness-ra.webp 1376w, https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/measuring-surface-roughness-ra-300x167.webp 300w, https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/measuring-surface-roughness-ra-1024x572.webp 1024w, https:\/\/www.jcinjectionmolding.com\/wp-content\/uploads\/2026\/08\/measuring-surface-roughness-ra-768x429.webp 768w\" sizes=\"auto, (max-width: 1376px) 100vw, 1376px\" \/><\/p>\n<div style=\"margin-bottom: 30px\">\n<h3 style=\"font-size: 22px;line-height: 1.5em;font-weight: bold;margin-top: 24px;margin-bottom: 12px;color: #111111\">What is the difference between SPI A-1 and VDI 24 surface finishes?<\/h3>\n<p style=\"font-size: 18px;line-height: 1.8em;text-align: left;margin-bottom: 24px\">SPI A-1 represents an optical diamond mirror finish polished to a smooth surface roughness Ra under 0.012 microns, ideal for transparent lenses. VDI 24 is a matte spark-erosion texture produced by electrical discharge machining, offering a medium tactile grip that masks cosmetic sink marks and scratch defects on opaque enclosures.<\/p>\n<\/div>\n<div style=\"margin-bottom: 30px\">\n<h3 style=\"font-size: 22px;line-height: 1.5em;font-weight: bold;margin-top: 24px;margin-bottom: 12px;color: #111111\">Why do textured mold cavities require larger draft angles than polished cavities?<\/h3>\n<p style=\"font-size: 18px;line-height: 1.8em;text-align: left;margin-bottom: 24px\">Textured cavity walls feature microscopic peaks and valleys that mechanically grip the shrinking plastic during cooling. Insufficient draft angles cause the plastic skin to drag against the textured steel during ejection, creating unsightly scuff marks. Adding 1\u00b0 of draft for every 0.025 mm of texture depth ensures smooth release without damaging the pattern.<\/p>\n<\/div>\n<div style=\"margin-bottom: 0\">\n<h3 style=\"font-size: 22px;line-height: 1.5em;font-weight: bold;margin-top: 24px;margin-bottom: 12px;color: #111111\">How do conductive spray coatings provide EMI shielding in plastic housings?<\/h3>\n<p style=\"font-size: 18px;line-height: 1.8em;text-align: left;margin-bottom: 24px\">Conductive spray coatings contain microscopic nickel, copper, or silver flakes suspended in a liquid binder. When sprayed onto the internal surfaces of a plastic enclosure, the metal particles form a continuous conductive grid. This metallic layer reflects and absorbs electromagnetic radiation, preventing high-frequency noise from interfering with delicate electronic components.<\/p>\n<\/div>\n<\/section>\n<\/article>","protected":false},"excerpt":{"rendered":"<p>Elevating plastic hardware aesthetics, tactile ergonomics, and electromagnetic performance requires comprehensive post-molding decoration and cavity surface conditioning. Standard raw molded plastic parts frequently display flow lines, parting line seams, or ejection pin marks that compromise visual quality. Applying specialized mold textures, diamond mirror polishes, conductive coatings, or multi-color pad printing transforms bare polymer parts into [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":2909,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-2903","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"_links":{"self":[{"href":"https:\/\/www.jcinjectionmolding.com\/de\/wp-json\/wp\/v2\/posts\/2903","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.jcinjectionmolding.com\/de\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.jcinjectionmolding.com\/de\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.jcinjectionmolding.com\/de\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.jcinjectionmolding.com\/de\/wp-json\/wp\/v2\/comments?post=2903"}],"version-history":[{"count":0,"href":"https:\/\/www.jcinjectionmolding.com\/de\/wp-json\/wp\/v2\/posts\/2903\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.jcinjectionmolding.com\/de\/wp-json\/wp\/v2\/media\/2909"}],"wp:attachment":[{"href":"https:\/\/www.jcinjectionmolding.com\/de\/wp-json\/wp\/v2\/media?parent=2903"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.jcinjectionmolding.com\/de\/wp-json\/wp\/v2\/categories?post=2903"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.jcinjectionmolding.com\/de\/wp-json\/wp\/v2\/tags?post=2903"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}