{"id":14106,"date":"2022-11-24T17:23:17","date_gmt":"2022-11-24T09:23:17","guid":{"rendered":"https:\/\/zetarmold.com\/?p=14106"},"modified":"2026-05-02T01:46:21","modified_gmt":"2026-05-01T17:46:21","slug":"eva-enjeksi%cc%87yon-kaliplama","status":"publish","type":"post","link":"https:\/\/zetarmold.com\/tr\/eva-enjeksi%cc%87yon-kaliplama\/","title":{"rendered":"Shore Sertli\u011fi"},"content":{"rendered":"<p>ZetarMold\u2019\u0131n m\u00fchendislik ekibinden malzeme tavsiyeleri, DFM geri bildirimleri ve \u00fcretim fiyatlar\u0131 al\u0131n \u2014 90T\u2019den 1850T\u2019ye kadar 45 makineyle tamamen i\u00e7 imalat kal\u0131p \u00fcretimi yap\u0131yoruz.<a href=\"https:\/\/en.wikipedia.org\/wiki\/Ethylene-vinyl_acetate\">ethylene-vinyl acetate<\/a><sup id=\"fnref1:1\"><a href=\"#fn:1\" class=\"footnote-ref\">1<\/a><\/sup>) injection molding has a narrower processing window than most thermoplastics, and the foam expansion behavior catches a lot of people off guard. This article walks you through what actually matters: temperatures, shrinkage, mold design gotchas, and how to avoid the three defects that kill EVA parts most often.<\/p>\n<div class=\"callout-key\" style=\"background:#f0f7ff; border-left:4px solid #2563eb; padding:1em 1.2em; border-radius:6px; margin:1.5em 0;\">\n<strong>\u00d6nemli \u00c7\u0131kar\u0131mlar<\/strong><\/p>\n<ul>\n<li>EVA processes at 160\u2013220 \u00b0C; exceeding 250 \u00b0C causes decomposition<\/li>\n<li>Shrinkage runs 1.0\u20132.0% \u2014 double that of PP or PE<\/li>\n<li>Wall thickness should stay between 1.5 mm and 4.0 mm<\/li>\n<li>Mold temperature 20\u201340 \u00b0C; cold runners preferred<\/li>\n<li>VA content (8\u201328%) determines flexibility and foam density<\/li>\n<\/ul>\n<\/div>\n<h2>What Is EVA Injection Molding and When Should You Use It?<\/h2>\n<p>Eva injection molding and when should you use it is defined by the function, constraints, and tradeoffs explained in this section. EVA injection molding is the process of shaping ethylene-vinyl acetate copolymer \u2014 a foamable thermoplastic \u2014 using conventional <a href=\"https:\/\/zetarmold.com\/tr\/injection-molding-complete-guide\/\">enjeksiyon kal\u0131plama<\/a> equipment. The VA (vinyl acetate) content typically ranges from 8% to 28%, and that percentage is the single most important variable: low VA (8\u201314%) gives you a stiff, PE-like material; high VA (18\u201328%) gives you a soft, rubbery foam.<\/p>\n<p>In practice, EVA is the go-to material when you need lightweight cushioning with good impact absorption. Think shoe midsoles, sports padding, helmet liners, yoga mats, and protective packaging. It\u2019s not the right choice if you need structural rigidity, chemical resistance, or tight dimensional tolerances \u2014 for those, look at <a href=\"https:\/\/zetarmold.com\/tr\/injection-mold-complete-guide\/\">enjeksiyon kal\u0131b\u0131<\/a> applications using PC, PA, or POM.<\/p>\n<p>The key difference between EVA and standard thermoplastics: EVA expands during cooling. That foam expansion is what gives you the cushioning and low density (0.15\u20130.40 g\/cm\u00b3 for foam grades), but it also means shrinkage is less predictable and part dimensions shift more than you\u2019d expect from a standard polymer.<\/p>\n<div class=\"claim claim-true\" style=\"background-color: #eff7ef; border-color: #eff7ef; color: #5a8a5a;\">\n<p><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"20\" height=\"20\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"#16a34a\" stroke-width=\"2\"><path d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><b>\u201cStandard injection molding machines can process EVA without modification.\u201d<\/b><span class=\"claim-true-or-false\">Do\u011fru<\/span><\/p>\n<p class=\"claim-explanation\">True. A general-purpose screw (20:1 L\/D ratio) and standard barrel work fine. The only recommended addition is a closed-loop nozzle to prevent drool, since EVA\u2019s low melt viscosity causes material to leak from open nozzles during hold and cooling phases.<\/p>\n<\/div>\n<div class=\"claim claim-false\" style=\"background-color: #f7e8e8; border-color: #f7e8e8; color: #8a4a4a;\">\n<p><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"20\" height=\"20\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"#dc2626\" stroke-width=\"2\"><line x1=\"18\" y1=\"6\" x2=\"6\" y2=\"18\"\/><line x1=\"6\" y1=\"6\" x2=\"18\" y2=\"18\"\/><\/svg><b>\u201cEVA is just a type of polyethylene and processes exactly like PE.\u201d<\/b><span class=\"claim-true-or-false\">Yanl\u0131\u015f<\/span><\/p>\n<p class=\"claim-explanation\">False. While EVA is a copolymer of ethylene and vinyl acetate, the VA content fundamentally changes its behavior. EVA foam expands during cooling, has 2\u20134\u00d7 higher shrinkage than PE, and decomposes at a lower temperature (250 \u00b0C vs. 300+ \u00b0C for PE). Running EVA on PE settings will give you flash, burn marks, and dimensional rejects.<\/p>\n<\/div>\n<h2>Enjeksiyon Kal\u0131plama Ad\u0131mlar\u0131nda EVA'y\u0131 Kontrol Eden \u0130\u015fleme Parametreleri Nedir?<\/h2>\n<p>Bu b\u00f6l\u00fcm, enjeksiyon kal\u0131plama ad\u0131mlar\u0131nda eva'n\u0131n i\u015fleme parametrelerinin kontrol\u00fc ve bunun maliyet, kalite, zamanlama veya kaynak riski \u00fczerindeki etkisi hakk\u0131nda. EVA i\u015flemesi ayn\u0131 <a href=\"https:\/\/zetarmold.com\/tr\/enjeksiyon-kaliplama-adimlari\/\">enjeksiyon kal\u0131plama ad\u0131mlar\u0131<\/a> di\u011fer termoplastiklerde oldu\u011fu gibi, ancak \u0131s\u0131 ve kalma zaman\u0131 kontrol edilmezse EVA k\u00f6p\u00fcklenebilir, s\u0131zabilir veya bozunabilir, bu nedenle s\u0131cakl\u0131k penceresi dar. Namlu s\u0131cakl\u0131\u011f\u0131, kal\u0131p s\u0131cakl\u0131\u011f\u0131, enjeksiyon h\u0131z\u0131, tutma bas\u0131nc\u0131 ve so\u011fuma zaman\u0131yla ba\u015flay\u0131n, ard\u0131ndan deneme s\u0131ras\u0131nda bir de\u011fi\u015fkeni ad\u0131m ad\u0131m ayarlay\u0131n.<\/p>\n<table style=\"width:100%;border-collapse:collapse;margin:1.5em 0;\">\n<caption style=\"font-weight:bold;margin-bottom:0.5em;\">EVA injection molding processing parameters<\/caption>\n<thead>\n<tr>\n<th style=\"border:1px solid #ddd;padding:8px;background:#f5f5f5;\">Parametre<\/th>\n<th style=\"border:1px solid #ddd;padding:8px;background:#f5f5f5;\">Range<\/th>\n<th style=\"border:1px solid #ddd;padding:8px;background:#f5f5f5;\">Notlar<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border:1px solid #ddd;padding:8px;\">Erime s\u0131cakl\u0131\u011f\u0131<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">160\u2013220 \u00b0C<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Above 250 \u00b0C = decomposition (acetic acid odor)<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #ddd;padding:8px;\">Kal\u0131p s\u0131cakl\u0131\u011f\u0131<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">20\u201340 \u00b0C<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Cool water circuits; higher temps worsen shrinkage<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #ddd;padding:8px;\">Enjeksiyon bas\u0131nc\u0131<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">40\u201380 MPa<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Lower than rigid plastics; too much pressure compresses foam<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #ddd;padding:8px;\">Enjeksiyon h\u0131z\u0131<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Medium to slow<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Fast fills trap air and cause burn marks<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #ddd;padding:8px;\">Tutma bas\u0131nc\u0131<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">20\u201340 MPa<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Short hold time (2\u20135 s); foam expansion does the rest<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #ddd;padding:8px;\">Drying temperature<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">60\u201370 \u00b0C<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">2\u20134 hours; EVA absorbs less moisture than nylon but still needs drying<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #ddd;padding:8px;\">K\u00fc\u00e7\u00fclme<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">1.0\u20132.0%<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Higher VA content = higher shrinkage<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>The biggest mistake we see: running EVA at the same temperatures you\u2019d use for PE or PP. EVA\u2019s thermal window is tighter. If you smell vinegar (acetic acid) during molding, you\u2019ve already crossed into decomposition territory \u2014 drop the barrel temperature 15\u201320 \u00b0C and purge the barrel.<\/p>\n<p>Another common oversight is holding pressure and time. EVA foam parts need very short hold times \u2014 2 to 5 seconds at most. The foam expansion packs the cavity from the inside. If you hold pressure too long, you compress the foam structure and end up with dense, heavy spots that should be soft and lightweight.<\/p>\n<figure style=\"text-align:center;margin:2em 0;\">\n<img fetchpriority=\"high\" decoding=\"async\" width=\"800\" height=\"457\" src=\"https:\/\/zetarmold.com\/wp-content\/uploads\/2026\/03\/im-vs-cnc-tolerance.webp\" alt=\"Injection Molding Product vs CNC machining tolerance\" class=\"wp-image-52399 size-full\" style=\"max-width:100%;height:auto;\" srcset=\"https:\/\/zetarmold.com\/wp-content\/uploads\/2026\/03\/im-vs-cnc-tolerance.webp 800w, https:\/\/zetarmold.com\/wp-content\/uploads\/2026\/03\/im-vs-cnc-tolerance-300x171.webp 300w, https:\/\/zetarmold.com\/wp-content\/uploads\/2026\/03\/im-vs-cnc-tolerance-768x439.webp 768w, https:\/\/zetarmold.com\/wp-content\/uploads\/2026\/03\/im-vs-cnc-tolerance-18x10.webp 18w, https:\/\/zetarmold.com\/wp-content\/uploads\/2026\/03\/im-vs-cnc-tolerance-600x343.webp 600w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><figcaption style=\"font-size:0.78em; color:#888; font-style:italic; margin-top:4px; text-align:center;\">Tolerance comparison: injection molding vs CNC<\/figcaption><\/figure>\n<h2>How Does VA Content Affect EVA Material Properties?<\/h2>\n<p>The VA percentage is the dial that controls everything \u2014 hardness, flexibility, transparency, foam density, and chemical resistance. Here\u2019s how it breaks down in real applications:<\/p>\n<table style=\"width:100%;border-collapse:collapse;margin:1.5em 0;\">\n<caption style=\"font-weight:bold;margin-bottom:0.5em;\">EVA properties by VA content percentage<\/caption>\n<thead>\n<tr>\n<th style=\"border:1px solid #ddd;padding:8px;background:#f5f5f5;\">VA Content<\/th>\n<th style=\"border:1px solid #ddd;padding:8px;background:#f5f5f5;\">Shore Hardness<\/th>\n<th style=\"border:1px solid #ddd;padding:8px;background:#f5f5f5;\">\u00d6zellikler<\/th>\n<th style=\"border:1px solid #ddd;padding:8px;background:#f5f5f5;\">Tipik Uygulamalar<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border:1px solid #ddd;padding:8px;\">30\u201360 saniye (daha uzun, k\u00f6p\u00fck so\u011futma)<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Shore D 40\u201355<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Stiff, PE-like, good clarity<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Rigid packaging, tubing, automotive interior trim<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #ddd;padding:8px;\">15\u201318%<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Shore A 80\u201395<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Flexible but resilient<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Wire jacketing, squeeze toys, grips<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #ddd;padding:8px;\">19\u201328%<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Shore A 30\u201370<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Soft, rubbery, excellent foamability<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Shoe midsoles, sports padding, yoga mats, helmet liners<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>For injection-molded foam parts (which is what most people mean by \u201cEVA molding\u201d), you\u2019re almost always in the 18\u201328% VA range. The material is compounded with a chemical blowing agent (typically <a href=\"https:\/\/en.wikipedia.org\/wiki\/Azodicarbonamide\">azodicarbonamide<\/a><sup id=\"fnref1:2\"><a href=\"#fn:2\" class=\"footnote-ref\">2<\/a><\/sup> or sodium bicarbonate) that activates at a specific temperature, releasing gas and expanding the part as it cools.<\/p>\n<p>Practical tip: if you\u2019re getting inconsistent part weights, the blowing agent distribution is your first suspect. Ask your material supplier for a masterbatch with pre-dispersed blowing agent rather than trying to mix it on the machine. The consistency improvement is worth the 10\u201315% material cost premium.<\/p>\n<div class=\"claim claim-true\" style=\"background-color: #eff7ef; border-color: #eff7ef; color: #5a8a5a;\">\n<p><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"20\" height=\"20\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"#16a34a\" stroke-width=\"2\"><path d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><b>\u201cHigher VA content in EVA results in softer, more flexible material with better foamability.\u201d<\/b><span class=\"claim-true-or-false\">Do\u011fru<\/span><\/p>\n<p class=\"claim-explanation\">True. As VA content increases from 8% to 28%, the material transitions from stiff and PE-like to soft and rubbery. The higher VA content also means more foam expansion is possible, producing lower-density parts with better cushioning properties.<\/p>\n<\/div>\n<div class=\"claim claim-false\" style=\"background-color: #f7e8e8; border-color: #f7e8e8; color: #8a4a4a;\">\n<p><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"20\" height=\"20\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"#dc2626\" stroke-width=\"2\"><line x1=\"18\" y1=\"6\" x2=\"6\" y2=\"18\"\/><line x1=\"6\" y1=\"6\" x2=\"18\" y2=\"18\"\/><\/svg><b>\u201cYou can simply add more blowing agent to any EVA grade to get better foam.\u201d<\/b><span class=\"claim-true-or-false\">Yanl\u0131\u015f<\/span><\/p>\n<p class=\"claim-explanation\">False. Blowing agent dosage must be matched to the VA content and the target foam density. Too much blowing agent causes large, irregular cells that weaken the part structure and can cause surface blistering. The agent also has a shelf life (6\u201312 months) \u2014 expired material won\u2019t activate properly regardless of quantity.<\/p>\n<\/div>\n<h2>What Are the Common Defects in EVA Injection Molding?<\/h2>\n<p>EVA has three recurring defects that account for probably 80% of quality issues we\u2019ve seen on the shop floor:<\/p>\n<p>1. Sink marks and surface depressions. Because EVA foam expands during cooling, thick sections continue pushing material outward while thinner adjacent sections have already solidified. The result is visible depressions on the show surface. Fix: keep wall thickness as uniform as possible, aim for a 2:1 ratio (maximum) between thickest and thinnest sections.<\/p>\n<p>2. Incomplete fills (short shots) with foam parts. The foam expansion helps pack the mold, but if melt temperature is too low or injection speed too slow, the material skin-freezes before the cavity fills. Fix: increase melt temp by 5\u201310 \u00b0C, increase injection speed one notch, and verify your blowing agent hasn\u2019t expired (yes, blowing agents have shelf lives \u2014 typically 6\u201312 months).<\/p>\n<p>3. Burn marks and discoloration. This is thermal decomposition \u2014 the vinegar smell is the giveaway. EVA starts breaking down above 250 \u00b0C, and decomposed material produces dark streaks or brown burn marks. Fix: lower barrel temperature, slow down screw speed (reduces shear heating), and check that your nozzle isn\u2019t running hotter than the barrel zones.<\/p>\n<p>One more thing: EVA\u2019s low viscosity at processing temperature means flash is a real risk, especially on parting lines. If your mold has worn inserts or marginal shut-off surfaces, you\u2019ll see flash at pressures that would be fine for PP or ABS. Budget for tighter mold tolerances if you\u2019re tooling up for EVA.<\/p>\n<h2>How Should You Design Molds for EVA Parts?<\/h2>\n<p>Bu b\u00f6l\u00fcm, EVA par\u00e7alar i\u00e7in kal\u0131p tasar\u0131m\u0131 ve bunun maliyet, kalite, zamanlama veya kaynak riskine etkisiyle ilgilidir. EVA i\u00e7in kal\u0131p tasar\u0131m\u0131 sert termoplastikler i\u00e7in tasar\u0131m ile ayn\u0131 de\u011fildir. K\u00f6p\u00fck geni\u015flemesi kurallar\u0131 \u00fc\u00e7 ana alanda de\u011fi\u015ftirir:<\/p>\n<p>Gate design: Use larger gates than you would for equivalent-sized rigid parts. Tab gates or fan gates with 1.5\u20133.0 mm thickness work well. Avoid pinpoint gates \u2014 the material\u2019s low viscosity and foam expansion will jet through a small gate and create swirl marks on the visible surface.<\/p>\n<p>Wall thickness: Target 1.5\u20134.0 mm. Below 1.5 mm, foam expansion can\u2019t develop properly and you get dense, stiff sections. Above 4.0 mm, shrinkage and sink marks become difficult to control. If your part has functional thick sections (like a shoe sole heel area), coring out the back reduces the effective thickness without losing the external profile.<\/p>\n<p>Draft and ejection: EVA\u2019s flexibility actually helps here \u2014 the part compresses during ejection and rebounds. But foam parts tend to stick in deep ribs. Minimum 1.5\u00b0 draft per side (2\u00b0 is better), and use generous ejector pin diameters. Small pins on a soft foam part just punch holes instead of pushing the part out.<\/p>\n<figure style=\"text-align:center;margin:2em 0;\">\n<img decoding=\"async\" width=\"800\" height=\"457\" src=\"https:\/\/zetarmold.com\/wp-content\/uploads\/2025\/12\/injection-mold-lifter-diagram.webp\" alt=\"Injection mold lifter and ejector stroke diagram\" class=\"wp-image-51673 size-full\" style=\"max-width:100%;height:auto;\" srcset=\"https:\/\/zetarmold.com\/wp-content\/uploads\/2025\/12\/injection-mold-lifter-diagram.webp 800w, https:\/\/zetarmold.com\/wp-content\/uploads\/2025\/12\/injection-mold-lifter-diagram-300x171.webp 300w, https:\/\/zetarmold.com\/wp-content\/uploads\/2025\/12\/injection-mold-lifter-diagram-768x439.webp 768w, https:\/\/zetarmold.com\/wp-content\/uploads\/2025\/12\/injection-mold-lifter-diagram-18x10.webp 18w, https:\/\/zetarmold.com\/wp-content\/uploads\/2025\/12\/injection-mold-lifter-diagram-600x343.webp 600w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><figcaption style=\"font-size:0.78em; color:#888; font-style:italic; margin-top:4px; text-align:center;\">Ejector system design \u2014 larger pin<\/figcaption><\/figure>\n<p>Cooling: EVA parts demold hot \u2014 the foam continues expanding for several seconds after the mold opens. Design cooling circuits for rapid surface chill, and expect cycle times of 30\u201360 seconds depending on wall thickness. Water at 15\u201325 \u00b0C works well; heated molds offer no benefit for EVA.<\/p>\n<div class=\"factory-insight\" data-fact-ids=\"location.shanghai_factory,equipment.injection_machines_47,equipment.tonnage_90_1850,team.production_120_plus,company.experience_20_years\" style=\"background:#f0f7ff;border-left:4px solid #0066cc;padding:12px 16px;margin:1.5em 0;\"><strong>\ud83c\udfed ZetarMold Factory Insight<\/strong><br \/>Shanghai fabrikam\u0131zda, ekibimiz 90T ila 1850T aras\u0131nda 47 enjeksiyon kal\u0131plama makinesi \u00e7al\u0131\u015ft\u0131r\u0131r. EVA par\u00e7alar i\u00e7in, m\u00fchendislerimiz kal\u0131plama \u00f6ncesinde d\u00fc\u015f\u00fck viskozite eriyik davran\u0131\u015f\u0131, hava kanallar\u0131, \u00e7\u0131karma alan\u0131 ve b\u00fcz\u00fclme riskini kontrol eder, 20+ y\u0131l kal\u0131plama deneyimi ve 120+ personel \u00fcretim ekibiyle hacim \u00fcretimi \u00f6ncesinde deneme sorunlar\u0131n\u0131 g\u00f6r\u00fcn\u00fcr tutar.<\/div>\n<div class=\"claim claim-true\" style=\"background-color: #eff7ef; border-color: #eff7ef; color: #5a8a5a;\">\n<p><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"20\" height=\"20\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"#16a34a\" stroke-width=\"2\"><path d=\"M9 16.17L4.83 12l-1.42 1.41L9 19 21 7l-1.41-1.41z\"\/><\/svg><b>\u201cEVA foam parts continue to expand for several seconds after the mold opens.\u201d<\/b><span class=\"claim-true-or-false\">Do\u011fru<\/span><\/p>\n<p class=\"claim-explanation\">True. Unlike rigid thermoplastics that shrink on demolding, EVA foam parts continue expanding as residual blowing agent completes its reaction and trapped gas cells equilibrate. This means cooling fixtures are often needed to maintain dimensional accuracy during the first 2\u20135 minutes after ejection.<\/p>\n<\/div>\n<div class=\"claim claim-false\" style=\"background-color: #f7e8e8; border-color: #f7e8e8; color: #8a4a4a;\">\n<p><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"20\" height=\"20\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"#dc2626\" stroke-width=\"2\"><line x1=\"18\" y1=\"6\" x2=\"6\" y2=\"18\"\/><line x1=\"6\" y1=\"6\" x2=\"18\" y2=\"18\"\/><\/svg><b>\u201cAluminum molds are never suitable for EVA injection molding production.\u201d<\/b><span class=\"claim-true-or-false\">Yanl\u0131\u015f<\/span><\/p>\n<p class=\"claim-explanation\">False. Aluminum molds work for prototyping and low-to-medium volume EVA production (under 100,000 shots). EVA is non-abrasive and processes at relatively low temperatures, so aluminum tool life can reach 50,000\u2013100,000 shots. For high-volume production, P20 steel is the standard choice.<\/p>\n<\/div>\n<h2>What Industries Use EVA Injection Molding the Most?<\/h2>\n<p>Bu b\u00f6l\u00fcm, en \u00e7ok EVA enjeksiyon kal\u0131plama kullan\u0131lan sekt\u00f6rler ve bunun maliyet, kalite, zamanlama veya kaynak riskine etkisiyle ilgilidir. EVA'n\u0131n hafiflik, yast\u0131klama ve nem direnci kombinasyonu, onu d\u00f6rt sekt\u00f6rde bask\u0131n hale getirir:<\/p>\n<p>Footwear (largest volume). Shoe midsoles, insoles, outsoles \u2014 EVA foam is the default material for athletic and casual footwear worldwide. The material can be color-matched, textured, and dual-density molded in a single shot. If you\u2019re <a href=\"https:\/\/zetarmold.com\/tr\/injection-molding-supplier-sourcing-guide\/\">sourcing<\/a> shoe molds, EVA compression molding (<a href=\"https:\/\/en.wikipedia.org\/wiki\/Ethylene-vinyl_acetate\">CMEVA<\/a><sup id=\"fnref1:3\"><a href=\"#fn:3\" class=\"footnote-ref\">3<\/a><\/sup>) is actually more common than injection for midsoles \u2014 but injection dominates for outsoles and smaller components.<\/p>\n<p>Sports and protective equipment. Helmet liners, shin guards, knee pads, mouth guards. EVA absorbs impact energy without bottoming out, and it retains its properties across a wide temperature range (-40 \u00b0C to +80 \u00b0C for most grades).<\/p>\n<p>Packaging. Protective inserts for electronics, medical devices, and fragile goods. EVA foam inserts can be molded to exact product shapes, providing better protection than cut PE foam at comparable cost for medium volumes (5,000\u2013100,000 units).<\/p>\n<p>Toys and consumer goods. Bath toys, pool floats, squeeze toys, grips, and handles. EVA\u2019s non-toxic nature (food-contact grades are available) and soft feel make it suitable for children\u2019s products, though you need to verify specific regulatory compliance (ASTM F963, EN 71) for your target market.<\/p>\n<h2>How Do EVA Processing Costs Compare to Other Materials?<\/h2>\n<p>EVA maliyeti sadece re\u00e7ine fiyat\u0131 de\u011fildir; toplam <a href=\"https:\/\/zetarmold.com\/tr\/enjeksiyon-kaliplama-uretim-suresi\/\">enjeksiyon kal\u0131plama \u00fcretim s\u00fcresi<\/a>, at\u0131k y\u00fczdesi, kal\u0131ptan \u00e7\u0131karma kararl\u0131l\u0131\u011f\u0131 ve kal\u0131p sonras\u0131 so\u011fuma alan\u0131. K\u00f6p\u00fck yo\u011funlu\u011fu de\u011fi\u015firse, par\u00e7alar uzun d\u00fcz so\u011fuma gerektirirse veya operat\u00f6rler \u00e7\u0131karma sonras\u0131 deforme olan yumu\u015fak par\u00e7alar\u0131 ay\u0131rmak i\u00e7in zaman harcarsa, ucuz bir malzeme hala pahal\u0131 olabilir.<\/p>\n<table style=\"width:100%;border-collapse:collapse;margin:1.5em 0;\">\n<caption style=\"font-weight:bold;margin-bottom:0.5em;\">EVA cost comparison with other common molding materials<\/caption>\n<thead>\n<tr>\n<th style=\"border:1px solid #ddd;padding:8px;background:#f5f5f5;\">Cost Factor<\/th>\n<th style=\"border:1px solid #ddd;padding:8px;background:#f5f5f5;\">EVA vs PP\/PE<\/th>\n<th style=\"border:1px solid #ddd;padding:8px;background:#f5f5f5;\">EVA vs TPU<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border:1px solid #ddd;padding:8px;\">Hammadde<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">+30\u201370%<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">-20\u201340%<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #ddd;padding:8px;\">\u00c7evrim s\u00fcresi<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">30\u201360s (longer, foam cooling)<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">EVA Enjeksiyon Kal\u0131plama: S\u00fcre\u00e7, Parametreler ve Tasar\u0131m \u0130pu\u00e7lar\u0131<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #ddd;padding:8px;\">Mold cost<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">+10\u201320% (tighter tolerances)<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">EVA Enjeksiyon Kal\u0131plama: S\u00fcre\u00e7, Parametreler ve Tasar\u0131m \u0130pu\u00e7lar\u0131<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #ddd;padding:8px;\">Scrap rate<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">5\u20138% (higher than rigid plastics)<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">EVA Enjeksiyon Kal\u0131plama: S\u00fcre\u00e7, Parametreler ve Tasar\u0131m \u0130pu\u00e7lar\u0131<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #ddd;padding:8px;\">Post-processing<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Often needs trimming\/deflashing<\/td>\n<td style=\"border:1px solid #ddd;padding:8px;\">Less<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>The bottom line: EVA is cost-effective when you need the specific combination of lightweight cushioning + moldability + color options. If you could achieve your requirements with PP or PE, those are cheaper. If you need the flexibility but also chemical resistance, TPU is the upgrade path.<\/p>\n<figure style=\"text-align:center;margin:2em 0;\">\n<img decoding=\"async\" width=\"800\" height=\"457\" src=\"https:\/\/zetarmold.com\/wp-content\/uploads\/2026\/04\/Factory-800x457-1.jpg\" alt=\"ZetarMold Injection Molding Factory\" class=\"wp-image-53339 size-full\" style=\"max-width:100%;height:auto;\" srcset=\"https:\/\/zetarmold.com\/wp-content\/uploads\/2026\/04\/Factory-800x457-1.jpg 800w, https:\/\/zetarmold.com\/wp-content\/uploads\/2026\/04\/Factory-800x457-1-300x171.jpg 300w, https:\/\/zetarmold.com\/wp-content\/uploads\/2026\/04\/Factory-800x457-1-768x439.jpg 768w, https:\/\/zetarmold.com\/wp-content\/uploads\/2026\/04\/Factory-800x457-1-18x10.jpg 18w, https:\/\/zetarmold.com\/wp-content\/uploads\/2026\/04\/Factory-800x457-1-600x343.jpg 600w\" sizes=\"(max-width: 800px) 100vw, 800px\" \/><figcaption style=\"font-size:0.78em; color:#888; font-style:italic; margin-top:4px; text-align:center;\">ZetarMold enjeksiyon kal\u0131plama fabrikas\u0131<\/figcaption><\/figure>\n<h2>What Are the Best Practices for EVA Injection Molding Production?<\/h2>\n<p>The best practices for eva injection molding production are the main categories or options explained in this section. After running EVA parts across hundreds of production orders, here\u2019s what actually makes a difference on the shop floor:<\/p>\n<p>Material handling: Dry EVA at 60\u201370 \u00b0C for 2\u20134 hours before molding. It doesn\u2019t absorb moisture like nylon, but surface moisture causes splay marks and inconsistent foam expansion. Store sealed \u2014 blowing agents degrade when exposed to humidity.<\/p>\n<p>Purge thoroughly between materials. EVA degrades quickly if it sits at barrel temperature without movement. If you\u2019re switching from EVA to another material (or vice versa), run 3\u20135 shots of purging compound. We\u2019ve seen cross-contamination ruin entire production runs \u2014 the acetic acid from decomposed EVA will corrode your barrel and screw over time.<\/p>\n<p>Monitor part weight, not just dimensions. For foam parts, weight is your best process indicator. Set up a weight control chart (X-bar R) and sample every 50\u2013100 shots. A \u00b13% weight drift tells you something has changed \u2014 usually barrel temperature or blowing agent activity \u2014 before you see dimensional issues.<\/p>\n<p>Design for demolding. EVA foam parts are warm and soft when they come out of the mold. They\u2019ll deform if you stack them immediately. Plan for 2\u20135 minutes of air cooling on a flat surface, or use cooling fixtures for parts with critical dimensions.<\/p>\n<div class=\"factory-insight\" data-fact-ids=\"materials.material_range_400_plus,certification.iso_9001_13485_14001_45001\" style=\"background:#f0f7ff;border-left:4px solid #0066cc;padding:12px 16px;margin:1.5em 0;\"><strong>\ud83c\udfed ZetarMold Factory Insight<\/strong><br \/>Ekibimiz 400+ plastik malzeme deneyimi sahibidir, yast\u0131klama, paketleme, t\u00fcketici \u00fcr\u00fcnleri ve medikal yak\u0131n uygulamalar i\u00e7in kullan\u0131lan \u00e7oklu EVA dereceleri dahil. ZetarMold ISO 9001, ISO 13485, ISO 14001 ve ISO 45001 sistemleri alt\u0131nda \u00e7al\u0131\u015f\u0131r, bu nedenle EVA malzeme se\u00e7imi, ilk par\u00e7a kontrol\u00fc, paketleme kontrolleri ve \u00e7\u0131k\u0131\u015f kontrol\u00fc hacim \u00fcretimi ba\u015flamadan \u00f6nce kaydedilebilir.<\/div>\n<h2>EVA Enjeksiyon Kal\u0131plama Hakk\u0131nda Sat\u0131n Al\u0131c\u0131lar Ne Sorular Sorar?<\/h2>\n<h2>S\u0131k\u00e7a Sorulan Sorular<\/h2>\n<h3>What temperature is used for EVA injection molding?<\/h3>\n<p>EVA genellikle 160 ila 220 C namlu s\u0131cakl\u0131\u011f\u0131nda ve 20 ila 40 C civar\u0131nda kal\u0131p s\u0131cakl\u0131\u011f\u0131nda i\u015flenir. Kesin ayarlar VA i\u00e7eri\u011fi, k\u00f6p\u00fck yo\u011funlu\u011fu, par\u00e7a kal\u0131nl\u0131\u011f\u0131 ve kimyasal k\u00f6p\u00fck olu\u015fturucu kullan\u0131m\u0131na ba\u011fl\u0131d\u0131r. Kritik kural, fazla \u0131s\u0131nmaktan ka\u00e7\u0131nmakt\u0131r. Yakla\u015f\u0131k 250 C \u00fczerinde, EVA bozunabilir ve koku, kahverengi lekeler ve ekipman korozyonu yaratabilen asidik yan \u00fcr\u00fcnler salabilir. D\u00fc\u015f\u00fck ba\u015flay\u0131n, ak\u0131\u015f kararl\u0131l\u0131\u011f\u0131n\u0131 kontrol edin, ard\u0131ndan deneme s\u0131ras\u0131nda s\u0131cakl\u0131\u011f\u0131 k\u00fc\u00e7\u00fck ad\u0131mlarla ayarlay\u0131n ve her de\u011fi\u015fimi kaydedin.<\/p>\n<h3>Can EVA be injection molded on standard machines?<\/h3>\n<p>Evet, EVA standart enjeksiyon kal\u0131plama makinelerinde \u00e7al\u0131\u015fabilir, ancak kurulum dikkat gerektirir, \u00e7\u00fcnk\u00fc eriyik yumu\u015fak ve d\u00fc\u015f\u00fck viskozitedir. Kapal\u0131 u\u00e7lu nozul s\u0131zmay\u0131 \u00f6nlemeye yard\u0131mc\u0131 olur ve genel ama\u00e7l\u0131 bir vida normal dereceler i\u00e7in genellikle yeterlidir. Kal\u0131p geni\u015f hava kanallar\u0131, d\u00fczg\u00fcn ak\u0131\u015f yollar\u0131 ve yeterli \u00e7\u0131karma alan\u0131na sahip olmal\u0131d\u0131r, \u00e7\u00fcnk\u00fc EVA k\u00f6p\u00fck geni\u015fleme sonras\u0131 bo\u015flu\u011fu tutabilir. \u00dcretim i\u00e7in, daha b\u00fcy\u00fck zorluk makine uyumlulu\u011fu de\u011fil; her parti i\u00e7in b\u00fcz\u00fclme, yo\u011funluk ve boyutsal tekrarlanabilirlik kontrol\u00fcd\u00fcr.<\/p>\n<h3>What is the shrinkage rate of EVA injection molded parts?<\/h3>\n<p>EVA b\u00fcz\u00fclmesi genellikle 1.0% ila 2.0% aras\u0131nda olur, ancak k\u00f6p\u00fck yo\u011funlu\u011fu, VA i\u00e7eri\u011fi, duvar kal\u0131nl\u0131\u011f\u0131 veya kal\u0131p s\u0131cakl\u0131\u011f\u0131 de\u011fi\u015fti\u011finde bu aral\u0131\u011f\u0131n d\u0131\u015f\u0131na \u00e7\u0131kabilir. Y\u00fcksek VA i\u00e7eri\u011fi ve g\u00fc\u00e7l\u00fc k\u00f6p\u00fcklenme genellikle b\u00fcz\u00fclmeyi art\u0131r\u0131r. Bu nedenle EVA kal\u0131plar\u0131 sadece nominal CAD boyutlar\u0131ndan kesilmemelidir. Beklenen b\u00fcz\u00fclme kal\u0131p tasar\u0131m\u0131nda dahil edilmelidir, ard\u0131ndan ilk par\u00e7a numunelerle kontrol edilmelidir. Kritik uyumlar i\u00e7in tam so\u011fuma sonras\u0131 par\u00e7alar \u00f6l\u00e7\u00fclmelidir, \u00e7\u00fcnk\u00fc EVA \u00e7\u0131karma ve depolama sonras\u0131 gev\u015femeye devam edebilir.<\/p>\n<h3>Is EVA injection molded foam recyclable?<\/h3>\n<p>EVA bir termoplastik oldu\u011fundan, teknik olarak at\u0131k yeniden \u00f6\u011f\u00fct\u00fclebilir ve yeniden i\u015flenebilir. S\u0131n\u0131rlama, k\u00f6p\u00fcklenmi\u015f EVA'n\u0131n ilk kal\u0131plama d\u00f6ng\u00fcs\u00fcnden sonra ayn\u0131 yap\u0131ya geri d\u00f6nmemesidir, \u00e7\u00fcnk\u00fc k\u00f6p\u00fck olu\u015fturucu reaksiyonu ger\u00e7ekle\u015fmi\u015ftir. Yeniden \u00f6\u011f\u00fctme genellikle yo\u011fun, daha az homojen par\u00e7alar \u00fcretir, bu nedenle kozmetik olmayan veya k\u00f6p\u00fcklenmemi\u015f uygulamalar i\u00e7in daha iyidir. Geri d\u00f6n\u00fc\u015ft\u00fcr\u00fclm\u00fc\u015f i\u00e7erik gerekiyorsa, \u00fcretim \u00f6ncesinde kesin yeniden \u00f6\u011f\u00fctme y\u00fczdesini test edin ve yo\u011funluk, y\u00fczey kalitesi, koku, b\u00fcz\u00fclme ve geri tepme de\u011fi\u015fimlerini validasyon denemelerinde izleyin.<\/p>\n<h3>What is the difference between EVA injection molding and compression molding?<\/h3>\n<p>Enjeksiyon kal\u0131plama, eriyik EVA'y\u0131 kapal\u0131 kal\u0131p bo\u015flu\u011funa zorlar, bu da karma\u015f\u0131k geometriler, \u00e7oklu bo\u015fluklu kal\u0131plar ve y\u00fcksek hacimli \u00fcretim serileri i\u00e7in daha iyi olmas\u0131n\u0131 sa\u011flar. Kompresyon kal\u0131plama (CMEVA), \u00f6nceden tart\u0131lm\u0131\u015f bir EVA bile\u015fimini a\u00e7\u0131k kal\u0131ba yerle\u015ftirir ve \u0131s\u0131 ve bas\u0131n\u00e7 alt\u0131nda kapat\u0131r \u2014 kompresyon t\u00fcm par\u00e7ada daha homojen k\u00f6p\u00fck yo\u011funlu\u011fu sa\u011flad\u0131\u011f\u0131 i\u00e7in d\u00fcz ayakkab\u0131 tabanlar\u0131 i\u00e7in standart i\u015flemdir. Enjeksiyon her d\u00f6ng\u00fc i\u00e7in daha h\u0131zl\u0131d\u0131r (30\u201360 saniye vs. kompresyon i\u00e7in 4\u20138 dakika) ancak karma\u015f\u0131k kal\u0131p gerektirir. \u00c7o\u011fu ayakkab\u0131 bile\u015feni i\u00e7in, par\u00e7a geometrisi ve \u00fcretim hacim gereksinimlerine ba\u011fl\u0131 olarak her iki metot beraber bulunur.<\/p>\n<h3>What wall thickness is recommended for EVA molded parts?<\/h3>\n<p>EVA enjeksiyon kal\u0131plama k\u00f6p\u00fc\u011f\u00fc i\u00e7in pratik bir duvar kal\u0131nl\u0131\u011f\u0131 aral\u0131\u011f\u0131 yakla\u015f\u0131k 1.5 ila 4.0 mm'dir. 1.5 mm alt\u0131ndaki ince kesitler stabil k\u00f6p\u00fck geni\u015flemesine izin vermeyebilirken, 4.0 mm \u00fczerindeki kal\u0131n kesitler \u00e7\u00f6kme izleri, dengesiz yo\u011funluk ve uzun so\u011fuma zaman\u0131 g\u00f6sterir. Duvar kal\u0131nl\u0131\u011f\u0131n\u0131 m\u00fcmk\u00fcn oldu\u011funca uniform tutun ve ani ge\u00e7i\u015flerden ka\u00e7\u0131n\u0131n. Kal\u0131n tampon gerekiyorsa, tek bir solid blok yapmak yerine nerv\u00fcrler, bo\u015fluk \u00f6zellikleri veya kontroll\u00fc k\u00f6p\u00fck yo\u011funlu\u011fu kullan\u0131n. \u0130lk-shot numuneler hem boyutlar\u0131 hem rebound hissiyi do\u011frulamal\u0131.<\/p>\n<hr style=\"margin:2em 0;border:none;border-top:1px solid #e0e0e0;\" \/>\n<ol class=\"footnotes\">\n<li id=\"fn:1\">\n<p><strong>ethylene-vinyl acetate:<\/strong> Ethylene-vinyl acetate is a copolymer of ethylene and vinyl acetate, where the VA percentage determines flexibility, foam density, and impact resistance. <a href=\"#fnref1:1\" class=\"footnote-backref\">\u21a9<\/a><\/p>\n<\/li>\n<li id=\"fn:2\">\n<p><strong>azodicarbonamide:<\/strong> Azodicarbonamide is a chemical blowing agent that decomposes at 200\u2013220 \u00b0C, releasing nitrogen gas to create foam structure in EVA and other polymers. <a href=\"#fnref1:2\" class=\"footnote-backref\">\u21a9<\/a><\/p>\n<\/li>\n<li id=\"fn:3\">\n<p><strong>CMEVA:<\/strong> Compression molded EVA (CMEVA) is a manufacturing process where pre-weighed EVA compound is placed in a heated mold and compressed, commonly used for shoe midsoles. <a href=\"#fnref1:3\" class=\"footnote-backref\">\u21a9<\/a><\/p>\n<\/li>\n<\/ol>","protected":false},"excerpt":{"rendered":"<p>EVA k\u00f6p\u00fck ayakkab\u0131 tabanlar\u0131 i\u00e7in bir teklif ald\u0131n\u0131z \u2014 50.000 \u00e7ift, alt\u0131 hafta i\u00e7inde teslim. Kal\u0131plar makul g\u00f6r\u00fcn\u00fcyor, ancak enjeksiyon at\u00f6lyeniz i\u015fi \"EVA zor bir malzeme\" diyerek reddetmeye devam ediyor. Haks\u0131z da de\u011filler. EVA (etilen-vinil asetat1) enjeksiyon kal\u0131plama, \u00e7o\u011fu termoplasti\u011fe g\u00f6re daha dar bir i\u015fleme penceresine sahiptir ve k\u00f6p\u00fck genle\u015fme davran\u0131\u015f\u0131 [\u2026]<\/p>","protected":false},"author":1,"featured_media":14183,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"none","_seopress_titles_title":"EVA Injection Molding: Process, Parameters & Design Tips","_seopress_titles_desc":"Practical guide to EVA injection molding \u2014 processing temperatures, shrinkage, mold design tips, and common defects. Based on 20+ years of shop-floor experience.","_seopress_robots_index":"","_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[42],"tags":[507,506,505],"meta_box":{"post-to-quiz_to":[]},"_links":{"self":[{"href":"https:\/\/zetarmold.com\/tr\/wp-json\/wp\/v2\/posts\/14106"}],"collection":[{"href":"https:\/\/zetarmold.com\/tr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zetarmold.com\/tr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/zetarmold.com\/tr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/zetarmold.com\/tr\/wp-json\/wp\/v2\/comments?post=14106"}],"version-history":[{"count":0,"href":"https:\/\/zetarmold.com\/tr\/wp-json\/wp\/v2\/posts\/14106\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/zetarmold.com\/tr\/wp-json\/wp\/v2\/media\/14183"}],"wp:attachment":[{"href":"https:\/\/zetarmold.com\/tr\/wp-json\/wp\/v2\/media?parent=14106"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zetarmold.com\/tr\/wp-json\/wp\/v2\/categories?post=14106"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zetarmold.com\/tr\/wp-json\/wp\/v2\/tags?post=14106"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}