{"id":393,"date":"2026-11-06T21:32:00","date_gmt":"2026-11-06T13:32:00","guid":{"rendered":"https:\/\/kerkepm.com\/knowledge\/extruder-maintenance-schedule\/"},"modified":"2026-11-08T20:42:58","modified_gmt":"2026-11-08T12:42:58","slug":"extruder-maintenance-schedule","status":"publish","type":"page","link":"https:\/\/kerkepm.com\/es\/knowledge\/extruder-maintenance-schedule\/","title":{"rendered":"Extruder Maintenance Schedule"},"content":{"rendered":"<div class=\"k3\">\n<div class=\"wrap\"><div class=\"crumbs\"><a href=\"\/\">Home<\/a><span>\/<\/span><a href=\"\/knowledge\/\">Knowledge<\/a><span>\/<\/span>Extruder Maintenance Schedule<\/div><\/div><div class=\"wrap\"><div class=\"hero\">\n<p class=\"kicker\">Service \u00b7 6 min read<\/p>\n<h1>Extruder Maintenance Schedule: 250 \/ 2,500 \/ 5,000 \/ 10,000 Hours<\/h1>\n<p class=\"dek\">What to check at each interval, and the three measurements that tell you a wear part is finished before it fails. A reference extruder maintenance schedule page from Kerke.<\/p>\n<div class=\"byline\"><div><b>Updated<\/b> 6 November 2026<\/div><div><b>Reviewed by<\/b> Kerke process team<\/div>\n<div><b>Basis<\/b> commissioning records, parameter table<\/div><\/div>\n<\/div><\/div>\n<div class=\"wrap\"><div class=\"grid\"><main>\n\n<p class=\"lead\">Maintenance on a compounding line is mostly measurement, not lubrication. The machine tells you it is wearing out through output, torque and pellet quality long before it makes noise.<\/p>\n\n<nav class=\"wp-block-rank-math-toc-block k3-toc\" aria-label=\"On this page\"><b>On this page:<\/b><a href=\"#rm-s1\">The intervals<\/a><a href=\"#rm-s2\">Three measurements that predict failure<\/a><a href=\"#rm-s3\">What to keep on the shelf<\/a><a href=\"#rm-s4\">Abrasive duty<\/a><a href=\"#rm-s5\">FAQ<\/a><\/nav><h2 class=\"sec\" id=\"intervals\" id=\"rm-s1\">The intervals<\/h2>\n<div class=\"tw\"><table>\n<caption><b>Table 1.<\/b> Recommended maintenance intervals. Abrasive filler and glass fibre move everything one step earlier.<\/caption>\n<thead><tr><th scope=\"col\">Interval<\/th><th scope=\"col\">What<\/th><th scope=\"col\">Acceptance<\/th><\/tr><\/thead>\n<tbody>\n<tr><td class=\"num\">250 h<\/td><td>Gearbox oil level and colour; heater bands; thermocouple calibration; screen changer seals; pelletizer blade gap<\/td><td>Oil clear, no milkiness; blade gap 0.05\u20130.1 mm<\/td><\/tr>\n<tr><td class=\"num\">2,500 h<\/td><td>Screw element inspection in the wear zone; liner clearance; vacuum line clean; water circuit filters; torque record review<\/td><td>Flight width loss &lt;1.5 mm; liner clearance &lt;0.3 mm<\/td><\/tr>\n<tr><td class=\"num\">5,000 h<\/td><td>Gearbox oil change and filter; coupling alignment; die plate flatness; heater band replacement as a set<\/td><td>Alignment &lt;0.05 mm; die flatness &lt;0.02 mm<\/td><\/tr>\n<tr><td class=\"num\">10,000 h<\/td><td>Gearbox inspection; shaft spline check; full screw set evaluation; electrical insulation test<\/td><td>Per manufacturer specification<\/td><\/tr>\n<\/tbody><\/table><\/div>\n\n<h2 class=\"sec\" id=\"three\" id=\"rm-s2\">Three measurements that predict failure<\/h2>\n<ol class=\"flow\">\n<li><b>Output at fixed settings<\/b>Weigh a 60-second sample monthly. A 5% drop from commissioning is the first sign of wear \u2014 earlier than any visual inspection.<\/li>\n<li><b>Liner clearance at the wear zone<\/b>Measure with a feeler gauge through the vent or die end. Above 0.3 mm, conveying efficiency falls and melt temperature rises.<\/li>\n<li><b>Torque at fixed output<\/b>Rising torque at constant output means the screw is doing more work to convey the same material: wear, or a changed material.<\/li>\n<\/ol>\n\n<h2 class=\"sec\" id=\"spares\" id=\"rm-s3\">What to keep on the shelf<\/h2>\n<p>One set of screw elements for the wear zone, one die plate, a full set of heater bands, four thermocouples, screen changer seals, pelletizer blades and a gearbox oil filter set. That list covers about 90% of unplanned stops, and it costs less than two days of downtime.<\/p>\n\n<h2 class=\"sec\" id=\"abrasive\" id=\"rm-s4\">Abrasive duty<\/h2>\n<p>For 85% CaCO<sub>3<\/sub> or 40% carbon black, halve the intervals. For glass fibre, inspect at 3,000 hours rather than 5,000. Bimetallic liners and PM (powder metallurgy) elements do not remove the need for inspection \u2014 they change the interval, not the discipline.<\/p>\n\n<h2 class=\"sec\" id=\"faq\" id=\"rm-s5\">FAQ<\/h2>\n<details open><summary>How often should gearbox oil be changed?<\/summary><p>First change at 500 hours, then every 5,000 hours with an annual oil analysis. Heat and torque excursions show up in the analysis before they show up as noise.<\/p><\/details><details><summary>Can I run without a spare screw set?<\/summary><p>For a single-line plant, no \u2014 a wear-related stop without spares costs weeks. For a plant with two identical lines, one shared set is usually enough.<\/p><\/details><details><summary>What shortens screw life most?<\/summary><p>Abrasive filler above 80%, glass fibre, and running with a worn liner (which increases slip and shear). Poor purge discipline comes fourth.<\/p><\/details>\n<div class=\"method\"><h2 id=\"rm-s6\">Where these numbers come from<\/h2>\n<p>Values are drawn from the Kerke parameter table, commissioning records and service reports from lines in the field. Temperature windows and consumption figures are typical ranges \u2014 confirm on your own material before they become a production setpoint.<\/p><\/div>\n<div class=\"related\"><h2 id=\"rm-s7\">Related reading<\/h2><div class=\"rel-grid\"><a class=\"rel\" href=\"\/knowledge\/twin-screw-extruder-troubleshooting\/\"><span>Knowledge<\/span>Twin Screw Extruder Troubleshooting: Nine Symptoms, Nine Causes<\/a><a class=\"rel\" href=\"\/knowledge\/twin-screw-extruder-startup\/\"><span>Knowledge<\/span>Twin Screw Extruder Startup: The 9-Step Sequence That Protects the Screw<\/a><\/div><\/div>\n<div class=\"cta\"><div><b>Tell us your material \u2014 we will tell you the line<\/b><p>Send 25\u201350 kg and we run it on our lab extruder: pellets, running video and a capacity report back in 3\u20137 days.<\/p><\/div>\n<div class=\"acts\"><a href=\"\/get-a-quote\/\">Get a quote<\/a>\n<a class=\"alt\" href=\"\/get-a-quote\/#trial\">Send material for trial<\/a><\/div><\/div>\n<\/main>\n<aside><h5>On this page<\/h5><ol><li><a href=\"#intervals\">The intervals<\/a><\/li><li><a href=\"#three\">Three measurements that predict failure<\/a><\/li><li><a href=\"#spares\">What to keep on the shelf<\/a><\/li><li><a href=\"#abrasive\">Abrasive duty<\/a><\/li><li><a href=\"#faq\">FAQ<\/a><\/li><\/ol>\n<div class=\"sidecard\"><b>Question not covered?<\/b><p>Send the material, the machine model and the symptom. We answer with a parameter sheet, not a brochure.<\/p>\n<a class=\"btn\" href=\"\/get-a-quote\/\">Ask an engineer<\/a>\n<a class=\"btn ghost\" href=\"\/knowledge\/\">All articles<\/a><\/div><\/aside><\/div><\/div>\n<script type=\"application\/ld+json\">{\"@context\": \"https:\/\/schema.org\", \"@graph\": [{\"@type\": \"TechArticle\", \"headline\": \"Extruder Maintenance Schedule: 250 \/ 2,500 \/ 5,000 \/ 10,000 Hours\", \"description\": \"What to check at each interval, and the three measurements that tell you a wear part is finished before it fails.\", \"datePublished\": \"2026-11-06\", \"dateModified\": \"2026-11-06\", \"inLanguage\": \"en\", \"author\": {\"@type\": \"Organization\", \"name\": \"Kerke Extrusion Equipment\"}, \"mainEntityOfPage\": \"https:\/\/www.kerkepm.com\/knowledge\/extruder-maintenance-schedule\/\"}, {\"@type\": \"FAQPage\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"How often should gearbox oil be changed?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"First change at 500 hours, then every 5,000 hours with an annual oil analysis. Heat and torque excursions show up in the analysis before they show up as noise.\"}}, {\"@type\": \"Question\", \"name\": \"Can I run without a spare screw set?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"For a single-line plant, no \u2014 a wear-related stop without spares costs weeks. For a plant with two identical lines, one shared set is usually enough.\"}}, {\"@type\": \"Question\", \"name\": \"What shortens screw life most?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Abrasive filler above 80%, glass fibre, and running with a worn liner (which increases slip and shear). Poor purge discipline comes fourth.\"}}]}]}<\/script>\n<div class=\"wrap\"><section class=\"k3-more\" id=\"rm-more\"><h2>Extruder maintenance schedule \u2014 the short version<\/h2><figure class=\"k3-fig\"><img decoding=\"async\" src=\"\/wp-content\/uploads\/2026\/11\/kte-65b-co-rotating-twin-screw-extruder-01-1200.webp\" alt=\"extruder maintenance schedule\" loading=\"lazy\" width=\"1200\" height=\"675\"><figcaption>Kerke test line, Nanjing \u2014 where the figures on this page were measured<\/figcaption><\/figure><p>Note on Extruder maintenance schedule: every figure on this page is a reference range measured on Kerke's own test line in Nanjing, not a catalogue maximum. If your material differs from the one in the table, send 25\u201350 kg and we will replace the range with a measured number.<\/p><p class=\"k3-rel\"><b>Related on this site:<\/b> <a href=\"\/machines\/co-rotating-twin-screw-extruder\/\">Twin screw extruder range<\/a> \u00b7 <a href=\"\/applications\/\">Extrusion lines by application<\/a> \u00b7 <a href=\"\/get-a-quote\/\">free extrusion line quotation<\/a> \u00b7 <a href=\"https:\/\/en.wikipedia.org\/wiki\/Pelletizing\" target=\"_blank\" rel=\"noopener\">Wikipedia: Pelletizing<\/a><\/p><\/section><\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Home\/Knowledge\/Extruder Maintenance Schedule Service \u00b7 6 min read Extruder Maintenance Schedule: 250 \/ 2,500 \/ 5,000 \/ 10,000 Hours What to check at each interval, and the three measurements that tell you a wear part is finished before it fails. A reference extruder maintenance schedule page from Kerke. Updated 6 November 2026Reviewed by Kerke process [&#8230;]\n","protected":false},"author":1,"featured_media":0,"parent":63,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"page-blank.php","meta":{"footnotes":""},"application":[],"app_group":[],"class_list":["post-393","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/kerkepm.com\/es\/wp-json\/wp\/v2\/pages\/393","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kerkepm.com\/es\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/kerkepm.com\/es\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/kerkepm.com\/es\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kerkepm.com\/es\/wp-json\/wp\/v2\/comments?post=393"}],"version-history":[{"count":0,"href":"https:\/\/kerkepm.com\/es\/wp-json\/wp\/v2\/pages\/393\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/kerkepm.com\/es\/wp-json\/wp\/v2\/pages\/63"}],"wp:attachment":[{"href":"https:\/\/kerkepm.com\/es\/wp-json\/wp\/v2\/media?parent=393"}],"wp:term":[{"taxonomy":"application","embeddable":true,"href":"https:\/\/kerkepm.com\/es\/wp-json\/wp\/v2\/application?post=393"},{"taxonomy":"app_group","embeddable":true,"href":"https:\/\/kerkepm.com\/es\/wp-json\/wp\/v2\/app_group?post=393"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}