{"id":100181,"date":"2026-02-15T20:25:27","date_gmt":"2026-02-15T20:25:27","guid":{"rendered":"https:\/\/vibromera.eu\/?post_type=calculator&#038;p=100181"},"modified":"2026-02-15T20:25:27","modified_gmt":"2026-02-15T20:25:27","slug":"paper-machine-roll-balance","status":"publish","type":"calculator","link":"https:\/\/vibromera.eu\/pt_br\/calculators\/paper-machine-roll-balance\/","title":{"rendered":"Calculadora de balanceamento de bobinas para m\u00e1quinas de papel | Classifica\u00e7\u00e3o e toler\u00e2ncia"},"content":{"rendered":"\n<script type=\"application\/ld+json\">\n{\"@context\":\"https:\/\/schema.org\",\"@type\":\"WebApplication\",\"name\":\"Paper Machine Roll Balance Calculator\",\"description\":\"Calculate permissible unbalance for paper machine rolls based on ISO 21940, surface speed, and roll dimensions.\",\"url\":\"https:\/\/vibromera.eu\/calculators\/paper-machine-roll-balance\/\",\"applicationCategory\":\"Engineering Calculator\",\"operatingSystem\":\"Any\",\"offers\":{\"@type\":\"Offer\",\"price\":\"0\",\"priceCurrency\":\"EUR\"},\"creator\":{\"@type\":\"Organization\",\"name\":\"Vibromera\",\"url\":\"https:\/\/vibromera.eu\/\"},\"inLanguage\":\"en\",\"isAccessibleForFree\":true}\n<\/script>\n\n<link rel=\"preconnect\" href=\"https:\/\/fonts.googleapis.com\">\n\n<link rel=\"preconnect\" href=\"https:\/\/fonts.gstatic.com\" crossorigin>\n\n<link href=\"https:\/\/fonts.googleapis.com\/css2?family=DM+Sans:ital,opsz,wght@0,9..40,300;0,9..40,400;0,9..40,500;0,9..40,600;0,9..40,700;1,9..40,400&#038;family=JetBrains+Mono:wght@400;500;600&#038;family=Fraunces:opsz,wght@9..144,700;9..144,800&#038;display=swap\" rel=\"stylesheet\">\n\n<link rel=\"stylesheet\" 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tr:nth-child(even){background:var(--vc-surface-alt)}\n.vc-related{display:flex;flex-wrap:wrap;gap:10px;margin-top:16px}\n.vc-related-link{display:inline-block;padding:8px 16px;font-family:var(--vc-font);font-size:13px;font-weight:600;background:var(--vc-surface-alt);color:var(--vc-ink-secondary);border:1px solid var(--vc-border);border-radius:var(--vc-radius);text-decoration:none;transition:all 0.15s}.vc-related-link:hover{border-color:var(--vc-accent);color:var(--vc-accent);background:var(--vc-accent-light)}\n.vc-presets{display:flex;flex-wrap:wrap;gap:8px;margin-top:18px;padding-top:18px;border-top:1px solid var(--vc-border-light)}\n.vc-presets-label{font-family:var(--vc-mono);font-size:11px;font-weight:500;letter-spacing:0.1em;text-transform:uppercase;color:var(--vc-ink-muted);width:100%;margin-bottom:2px}\n.vc-preset-btn{padding:5px 12px;font-family:var(--vc-font);font-size:12px;font-weight:500;border:1px solid var(--vc-border);border-radius:6px;background:var(--vc-surface-alt);color:var(--vc-ink-secondary);cursor:pointer;transition:all 0.15s}.vc-preset-btn:hover{border-color:var(--vc-accent);color:var(--vc-accent);background:var(--vc-accent-light)}\n.vc-promo{margin-top:24px;padding:20px;background:linear-gradient(135deg,var(--vc-accent-light),var(--vc-surface));border:1px solid var(--vc-border);border-radius:var(--vc-radius-lg);display:flex;align-items:center;gap:16px}\n.vc-promo-text{flex:1;font-size:14px;color:var(--vc-ink-secondary)}.vc-promo-text strong{color:var(--vc-ink)}\n.vc-promo-link{padding:8px 20px;font-size:13px;font-weight:700;color:#fff;background:var(--vc-accent);border-radius:var(--vc-radius);text-decoration:none;white-space:nowrap;transition:background 0.15s}.vc-promo-link:hover{background:var(--vc-accent-hover)}\n.vc-footer{text-align:center;padding:32px 16px;font-size:13px;color:var(--vc-ink-muted)}.vc-footer a{color:var(--vc-accent);text-decoration:none}.vc-footer a:hover{text-decoration:underline}.vc-footer-links{margin-top:8px;font-size:12px}.vc-footer-links a{margin:0 8px}\n@media print{.vc-section-body{max-height:none!important}.vc-results{max-height:none!important;padding:24px!important}.vc-copy-btn,.vc-presets,.vc-promo{display:none!important}}\n<\/style>\n\n<div class=\"vc-calculator\" id=\"vc-paper-roll\">\n\n<header class=\"vc-header\">\n    <p class=\"vc-header-eyebrow\">Free Engineering Tool<\/p>\n    <h1 class=\"vc-header-title\">Paper Machine Roll Balance Calculator<\/h1>\n    <p class=\"vc-header-subtitle\">Calculate operating RPM from surface speed, permissible residual unbalance per ISO 21940, centrifugal force from unbalance, and correction mass for paper machine rolls.<\/p>\n    <div class=\"vc-badges\">\n        <span class=\"vc-badge\">ISO 21940<\/span>\n        <span class=\"vc-badge\">G2.5 \u2013 G6.3<\/span>\n        <span class=\"vc-badge\">Paper Rolls<\/span>\n    <\/div>\n<\/header>\n\n<div class=\"vc-card\">\n    <form class=\"vc-form\" id=\"vc-form\" autocomplete=\"off\">\n        <div class=\"vc-form-grid\">\n            <div class=\"vc-field\">\n                <label class=\"vc-label\" for=\"vc-mass\">Roll Mass <span class=\"vc-label-hint\">(kg)<\/span><\/label>\n                <input class=\"vc-input\" type=\"number\" id=\"vc-mass\" inputmode=\"decimal\" step=\"any\" min=\"0\" placeholder=\"e.g. 2500\" value=\"2500\">\n            <\/div>\n            <div class=\"vc-field\">\n                <label class=\"vc-label\" for=\"vc-diam\">Roll Diameter <span class=\"vc-label-hint\">(mm)<\/span><\/label>\n                <input class=\"vc-input\" type=\"number\" id=\"vc-diam\" inputmode=\"decimal\" step=\"any\" min=\"0\" placeholder=\"e.g. 800\" value=\"800\">\n            <\/div>\n            <div class=\"vc-field\">\n                <label class=\"vc-label\" for=\"vc-speed\">Operating Speed <span class=\"vc-label-hint\">(m\/min surface speed)<\/span><\/label>\n                <input class=\"vc-input\" type=\"number\" id=\"vc-speed\" inputmode=\"decimal\" step=\"any\" min=\"0\" placeholder=\"e.g. 1200\" value=\"1200\">\n            <\/div>\n            <div class=\"vc-field\">\n                <label class=\"vc-label\" for=\"vc-width\">Roll Width <span class=\"vc-label-hint\">(mm)<\/span><\/label>\n                <input class=\"vc-input\" type=\"number\" id=\"vc-width\" inputmode=\"decimal\" step=\"any\" min=\"0\" placeholder=\"e.g. 8000\" value=\"8000\">\n            <\/div>\n            <div class=\"vc-field\">\n                <label class=\"vc-label\" for=\"vc-grade\">Balance Grade<\/label>\n                <select class=\"vc-select\" id=\"vc-grade\">\n                    <option value=\"1\">G1.0 \u2014 Precision rolls (calender, coating)<\/option>\n                    <option value=\"2.5\" selected>G2.5 \u2014 Standard paper rolls<\/option>\n                    <option value=\"6.3\">G6.3 \u2014 General rolls, press rolls<\/option>\n                    <option value=\"16\">G16 \u2014 Low-speed felt rolls<\/option>\n                <\/select>\n            <\/div>\n            <div class=\"vc-field\">\n                <label class=\"vc-label\" for=\"vc-planes\">Correction Planes<\/label>\n                <select class=\"vc-select\" id=\"vc-planes\">\n                    <option value=\"2\" selected>2 planes (50\/50 split)<\/option>\n                    <option value=\"1\">1 plane<\/option>\n                <\/select>\n            <\/div>\n        <\/div>\n        <div class=\"vc-presets\">\n            <div class=\"vc-presets-label\">Quick presets<\/div>\n            <button type=\"button\" class=\"vc-preset-btn\" data-m=\"2500\" data-d=\"800\" data-s=\"1200\" data-w=\"8000\" data-g=\"2.5\">Press Roll 2500 kg<\/button>\n            <button type=\"button\" class=\"vc-preset-btn\" data-m=\"1500\" data-d=\"600\" data-s=\"1500\" data-w=\"6000\" data-g=\"2.5\">Dryer Cylinder 1500 kg<\/button>\n            <button type=\"button\" class=\"vc-preset-btn\" data-m=\"800\" data-d=\"400\" data-s=\"800\" data-w=\"5000\" data-g=\"1\">Calender Roll 800 kg<\/button>\n        <\/div>\n    <\/form>\n\n    <div class=\"vc-results vc-visible\" id=\"vc-results\">\n        <div class=\"vc-results-head\">\n            <h2 class=\"vc-results-title\">Results<\/h2>\n            <button type=\"button\" class=\"vc-copy-btn\" id=\"vc-copy-btn\">\n                <svg width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><rect x=\"9\" y=\"9\" width=\"13\" height=\"13\" rx=\"2\"\/><path d=\"M5 15H4a2 2 0 01-2-2V4a2 2 0 012-2h9a2 2 0 012 2v1\"\/><\/svg> Copy\n            <\/button>\n        <\/div>\n        <div class=\"vc-result-grid\">\n            <div class=\"vc-rcard vc-rcard-primary\">\n                <div class=\"vc-rcard-label\">Permissible Residual Unbalance (Total)<\/div>\n                <div class=\"vc-rcard-value\" id=\"vc-r-ubal\">\u2014<\/div>\n            <\/div>\n            <div class=\"vc-rcard\">\n                <div class=\"vc-rcard-label\">Operating RPM<\/div>\n                <div class=\"vc-rcard-value\" id=\"vc-r-rpm\">\u2014<\/div>\n            <\/div>\n            <div class=\"vc-rcard\">\n                <div class=\"vc-rcard-label\">Per-Plane Unbalance<\/div>\n                <div class=\"vc-rcard-value\" id=\"vc-r-plane\">\u2014<\/div>\n            <\/div>\n            <div class=\"vc-rcard\">\n                <div class=\"vc-rcard-label\">Specific Unbalance (eccentricity)<\/div>\n                <div class=\"vc-rcard-value\" id=\"vc-r-ecc\">\u2014<\/div>\n            <\/div>\n            <div class=\"vc-rcard\">\n                <div class=\"vc-rcard-label\">Centrifugal Force at Tolerance Limit<\/div>\n                <div class=\"vc-rcard-value\" id=\"vc-r-force\">\u2014<\/div>\n            <\/div>\n            <div class=\"vc-rcard\">\n                <div class=\"vc-rcard-label\">Correction Mass at Roll OD<\/div>\n                <div class=\"vc-rcard-value\" id=\"vc-r-corrmass\">\u2014<\/div>\n            <\/div>\n        <\/div>\n    <\/div>\n<\/div>\n\n<!-- Theory -->\n<div class=\"vc-section vc-open\" id=\"vc-sec-theory\">\n    <button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"true\">\n        <span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">\ud83d\udcd8<\/span><span class=\"vc-section-title\">Theory &#038; Paper Roll Guidelines<\/span><\/span>\n        <svg class=\"vc-section-chevron\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M6 9l6 6 6-6\"\/><\/svg>\n    <\/button>\n    <div class=\"vc-section-body\">\n        <div class=\"vc-section-inner vc-theory\">\n            <h3>RPM from Surface Speed<\/h3>\n            <div class=\"vc-formula-box\">RPM = (Surface Speed [m\/min]) \/ (\u03c0 \u00d7 D [m])<\/div>\n            <p>Paper machine speeds are specified as web surface speed in m\/min. The roll RPM depends on the roll diameter.<\/p>\n\n            <h3>Typical Balance Grades for Paper Machine Rolls<\/h3>\n            <table class=\"vc-table\">\n                <thead><tr><th>Roll Type<\/th><th>Recommended Grade<\/th><th>Notes<\/th><\/tr><\/thead>\n                <tbody>\n                    <tr><td>Calender rolls<\/td><td>G1.0 \u2013 G2.5<\/td><td>Highest precision required<\/td><\/tr>\n                    <tr><td>Press rolls (solid\/vented)<\/td><td>G2.5<\/td><td>Standard for most press sections<\/td><\/tr>\n                    <tr><td>Suction rolls<\/td><td>G2.5 \u2013 G6.3<\/td><td>Shell perforations complicate balancing<\/td><\/tr>\n                    <tr><td>Dryer cylinders<\/td><td>G2.5 \u2013 G6.3<\/td><td>Condensate shifting changes balance<\/td><\/tr>\n                    <tr><td>Wire\/fabric guide rolls<\/td><td>G2.5<\/td><td>Small diameter, moderate speed<\/td><\/tr>\n                    <tr><td>Felt rolls<\/td><td>G6.3 \u2013 G16<\/td><td>Low speed, less critical<\/td><\/tr>\n                    <tr><td>Reel spool<\/td><td>G2.5<\/td><td>High speed, affects winding quality<\/td><\/tr>\n                <\/tbody>\n            <\/table>\n\n            <div class=\"vc-info-box\">\n                <p><strong>Paper industry note:<\/strong> Rolls operating above 1000 m\/min benefit from G2.5 or better. Dryer cylinders with condensate management (siphons, turbulence bars) may show apparent unbalance changes during operation due to condensate redistribution.<\/p>\n            <\/div>\n\n            <h3>Centrifugal Force from Unbalance<\/h3>\n            <p>The centrifugal force generated by unbalance at the tolerance limit is:<\/p>\n            <div class=\"vc-formula-box\">F = m \u00d7 e \u00d7 \u03c9\u00b2 = U_per \u00d7 \u03c9\u00b2 \/ 1000 [N]<\/div>\n            <p>Where U_per is in g\u00b7mm and \u03c9 in rad\/s. This force rotates at shaft speed and is transmitted to the bearings and support structure.<\/p>\n\n            <h3>Correction Mass Calculation<\/h3>\n            <p>The correction mass to be added or removed at a given radius:<\/p>\n            <div class=\"vc-formula-box\">m_corr = U_per \/ r [g]<\/div>\n            <p>Where r is the correction radius in mm (typically at the roll OD or at a specific correction plane location).<\/p>\n\n            <h3>Special Considerations for Paper Rolls<\/h3>\n            <ul>\n                <li><strong>Suction rolls:<\/strong> Shell perforations create periodic mass variations. Balance should be checked after re-drilling or shell replacement.<\/li>\n                <li><strong>Covered rolls (rubber\/polyurethane):<\/strong> Cover thickness variations affect balance. Re-balance after re-covering.<\/li>\n                <li><strong>Dryer cylinders:<\/strong> Condensate redistribution during startup causes transient unbalance. Allow stabilization before measuring.<\/li>\n                <li><strong>Variable crown rolls:<\/strong> Hydraulic crown pressure changes can affect balance state.<\/li>\n                <li><strong>Thermal crown:<\/strong> Uneven heating can cause temporary bowing \u2014 check that thermal steady state is reached before balancing.<\/li>\n            <\/ul>\n\n            <h3>Vibration Limits for Paper Machine Rolls<\/h3>\n            <p>Paper machines require very low vibration levels for paper quality. Typical bearing housing velocity limits:<\/p>\n            <ul>\n                <li><strong>Calender rolls:<\/strong> &lt; 1.0 mm\/s RMS (affects paper surface quality)<\/li>\n                <li><strong>Press rolls:<\/strong> &lt; 2.0 mm\/s RMS<\/li>\n                <li><strong>Dryer cylinders:<\/strong> &lt; 2.5 mm\/s RMS<\/li>\n                <li><strong>Wire\/felt guide rolls:<\/strong> &lt; 2.0 mm\/s RMS<\/li>\n                <li><strong>Reel spool:<\/strong> &lt; 1.5 mm\/s RMS (affects winding quality)<\/li>\n            <\/ul>\n        <\/div>\n    <\/div>\n<\/div>\n\n<!-- FAQ -->\n<div class=\"vc-section\" id=\"vc-sec-faq\">\n    <button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"false\">\n        <span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">\u2753<\/span><span class=\"vc-section-title\">Frequently Asked Questions<\/span><\/span>\n        <svg class=\"vc-section-chevron\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M6 9l6 6 6-6\"\/><\/svg>\n    <\/button>\n    <div class=\"vc-section-body\">\n        <div class=\"vc-section-inner\">\n            <div class=\"vc-faq-list\" id=\"vc-faq-list\"><\/div>\n        <\/div>\n    <\/div>\n<\/div>\n\n<!-- Related -->\n<div class=\"vc-section\" id=\"vc-sec-related\">\n    <button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"false\">\n        <span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">\ud83d\udd17<\/span><span class=\"vc-section-title\">Related Calculators<\/span><\/span>\n        <svg class=\"vc-section-chevron\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M6 9l6 6 6-6\"\/><\/svg>\n    <\/button>\n    <div class=\"vc-section-body\">\n        <div class=\"vc-section-inner\">\n            <div class=\"vc-related\">\n                <a class=\"vc-related-link\" href=\"\/calculators\/residual-unbalance-iso1940\/\">General Residual Unbalance<\/a>\n                <a class=\"vc-related-link\" href=\"\/calculators\/crusher-rotor-balance\/\">Crusher Rotor Balance<\/a>\n                <a class=\"vc-related-link\" href=\"\/calculators\/cooling-tower-fan-vibration\/\">Cooling Tower Fan<\/a>\n            <\/div>\n        <\/div>\n    <\/div>\n<\/div>\n\n<div class=\"vc-promo\">\n    <div class=\"vc-promo-text\"><strong>Vibromera \u2014 Portable Balancing &#038; Vibration Analysis<\/strong><br>Professional field balancing instruments and software. Used in 50+ countries.<\/div>\n    <a class=\"vc-promo-link\" href=\"https:\/\/vibromera.eu\/\" target=\"_blank\" rel=\"noopener\">Learn More<\/a>\n<\/div>\n<footer class=\"vc-footer\"><p>\u00a9 2024\u20132025 <a href=\"https:\/\/vibromera.eu\/\">Vibromera<\/a> \u2014 Engineering Calculators<\/p><p style=\"font-size:12px;margin-top:4px;\">Based on ISO 21940-11. Last updated: February 2025<\/p><div class=\"vc-footer-links\"><a href=\"\/calculators\/engineering-calculators\/\">All Calculators<\/a><a href=\"https:\/\/vibromera.eu\/contacts\/\">Contact<\/a><\/div><\/footer>\n\n<\/div>\n\n<script>\n(function() {\n    'use strict';\n    function $(id){return document.getElementById(id)}\n    function fmt(n,d){if(isNaN(n)||!isFinite(n))return'\u2014';var f=n.toFixed(d===undefined?2:d);return f.replace(\/(\\.\\d*?)0+$\/,'$1').replace(\/\\.$\/,'')}\n\n    function calculate(){\n        var mass=parseFloat($('vc-mass').value);\n        var diam=parseFloat($('vc-diam').value);\n        var speed=parseFloat($('vc-speed').value);\n        var width=parseFloat($('vc-width').value);\n        var grade=parseFloat($('vc-grade').value);\n        var planes=parseInt($('vc-planes').value);\n\n        if(!mass||mass<=0||!diam||diam<=0||!speed||speed<=0){$('vc-r-ubal').innerHTML='\u2014';return}\n\n        var diamM=diam\/1000;\n        var rpm=speed\/(Math.PI*diamM);\n        var omega=2*Math.PI*rpm\/60;\n        var eper=grade*1000\/omega;\n        var uper=eper*mass;\n        var uperPlane=uper\/planes;\n        var force=mass*(eper\/1e6)*omega*omega;\n        var corrMass=uper\/(diam\/2);\n\n        $('vc-r-rpm').innerHTML=fmt(rpm,1)+' <span class=\"vc-rcard-unit\">RPM<\/span>';\n        $('vc-r-ubal').innerHTML=(uper>=1000?fmt(uper,0):fmt(uper,1))+' <span class=\"vc-rcard-unit\">g\u00b7mm<\/span>';\n        $('vc-r-plane').innerHTML=(uperPlane>=1000?fmt(uperPlane,0):fmt(uperPlane,1))+' <span class=\"vc-rcard-unit\">g\u00b7mm per plane<\/span>';\n        $('vc-r-ecc').innerHTML=fmt(eper,2)+' <span class=\"vc-rcard-unit\">\u03bcm<\/span>';\n        $('vc-r-force').innerHTML=fmt(force,1)+' <span class=\"vc-rcard-unit\">N<\/span>';\n        $('vc-r-corrmass').innerHTML=fmt(corrMass,2)+' <span class=\"vc-rcard-unit\">g at r=' + fmt(diam\/2,0) + ' mm<\/span>';\n        $('vc-results').classList.add('vc-visible');\n    }\n\n    document.querySelectorAll('.vc-preset-btn').forEach(function(btn){\n        btn.addEventListener('click',function(e){\n            e.preventDefault();\n            $('vc-mass').value=this.getAttribute('data-m');\n            $('vc-diam').value=this.getAttribute('data-d');\n            $('vc-speed').value=this.getAttribute('data-s');\n            $('vc-width').value=this.getAttribute('data-w');\n            $('vc-grade').value=this.getAttribute('data-g');\n            calculate();\n        });\n    });\n\n    $('vc-form').addEventListener('input',calculate);\n    $('vc-form').addEventListener('change',calculate);\n\n    $('vc-copy-btn').addEventListener('click',function(){\n        var t='Paper Roll Balance\\n\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\\nMass: '+$('vc-mass').value+' kg\\nDiameter: '+$('vc-diam').value+' mm\\nSpeed: '+$('vc-speed').value+' m\/min\\nRPM: '+$('vc-r-rpm').textContent+'\\nTotal Unbalance: '+$('vc-r-ubal').textContent+'\\nPer-Plane: '+$('vc-r-plane').textContent+'\\n\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\u2501\\nvibromera.eu';\n        if(navigator.clipboard){navigator.clipboard.writeText(t).then(function(){var b=$('vc-copy-btn');b.classList.add('vc-copied');b.innerHTML='<svg width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><polyline points=\"20 6 9 17 4 12\"\/><\/svg> Copied!';setTimeout(function(){b.classList.remove('vc-copied');b.innerHTML='<svg width=\"14\" height=\"14\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><rect x=\"9\" y=\"9\" width=\"13\" height=\"13\" rx=\"2\"\/><path d=\"M5 15H4a2 2 0 01-2-2V4a2 2 0 012-2h9a2 2 0 012 2v1\"\/><\/svg> Copy'},2000)})}\n    });\n\n    document.querySelectorAll('.vc-section-toggle').forEach(function(btn){btn.addEventListener('click',function(){var s=this.closest('.vc-section');s.classList.toggle('vc-open');this.setAttribute('aria-expanded',s.classList.contains('vc-open'))})});\n\n    \/\/ FAQ\n    var faqData=[\n        {q:'What balance grade should I use for paper machine rolls?',a:'<p>It depends on the roll position. Calender and press rolls in high-speed machines (&gt;1000 m\/min) benefit from G2.5. Dryer cylinders typically use G6.3. Guide and felt rolls use G6.3. The general rule: the closer the roll is to the paper web forming and finishing, the tighter the balance requirement.<\/p>'},\n        {q:'Why is RPM calculated from surface speed and not directly entered?',a:'<p>Paper machine speeds are universally specified as surface (line) speed in m\/min, not as RPM. Different diameter rolls all run at the same surface speed (the machine speed), but at different RPMs. This calculator converts for you.<\/p>'},\n        {q:'How does condensate affect dryer cylinder balance?',a:'<p>Steam-heated dryer cylinders contain condensate that redistributes based on speed and siphon operation. At low speeds, condensate pools at the bottom (cascading regime) causing vibration. At higher speeds, it forms a uniform ring (rimming regime). Transition between regimes during ramp-up can cause temporary high vibration. Allow the machine to reach steady state before drawing balance conclusions.<\/p>'},\n        {q:'Can paper machine rolls be field-balanced?',a:'<p>Yes, in-situ (field) balancing is common for paper machine rolls, especially for dryer cylinders that are difficult to remove. Use vibration sensors on the bearing housings and a keyphasor on the shaft. Two-plane balancing is typically needed for long rolls (L\/D &gt; 0.5). Correction masses are added at dedicated balance weight locations on the roll heads.<\/p>'},\n        {q:'What causes a balanced roll to go out of balance?',a:'<p>Common causes include: cover wear or damage (rubber\/polyurethane), corrosion pitting on the shell, condensate system issues in dryer cylinders, thermal distortion, buildup of paper fiber or coating material, and cracking of the shell or heads. Regular vibration monitoring catches these issues early.<\/p>'},\n        {q:'How critical is balance for paper quality?',a:'<p>Very critical. Unbalance-induced vibration causes barring (regularly spaced marks) on calender and press rolls, uneven moisture profiles in press and dryer sections, and reel defects (corrugation, starring). Balance quality directly impacts paper surface quality and printability.<\/p>'}\n    ];\n    var faqList=$('vc-faq-list');\n    faqData.forEach(function(faq){faqList.innerHTML+='<div class=\"vc-faq-item\"><button type=\"button\" class=\"vc-faq-q\"><span>'+faq.q+'<\/span><svg class=\"vc-faq-chevron\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M6 9l6 6 6-6\"\/><\/svg><\/button><div class=\"vc-faq-a\"><div class=\"vc-faq-a-inner\">'+faq.a+'<\/div><\/div><\/div>'});\n    faqList.addEventListener('click',function(e){var btn=e.target.closest('.vc-faq-q');if(!btn)return;btn.closest('.vc-faq-item').classList.toggle('vc-open')});\n\n    calculate();\n})();\n<\/script>\n","protected":false},"excerpt":{"rendered":"<p>Calculadora online gratuita de balanceamento de bobinas de m\u00e1quinas de papel. Calcule a rota\u00e7\u00e3o operacional a partir da velocidade superficial, do desbalanceamento permitido pela norma ISO 21940, da for\u00e7a centr\u00edfuga e da massa de corre\u00e7\u00e3o para bobinas de papel.<\/p>","protected":false},"featured_media":0,"template":"","meta":{"ai_generated_summary":"","footnotes":""},"categories":[],"tags":[],"class_list":["post-100181","calculator","type-calculator","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/vibromera.eu\/pt_br\/wp-json\/wp\/v2\/calculator\/100181","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vibromera.eu\/pt_br\/wp-json\/wp\/v2\/calculator"}],"about":[{"href":"https:\/\/vibromera.eu\/pt_br\/wp-json\/wp\/v2\/types\/calculator"}],"version-history":[{"count":1,"href":"https:\/\/vibromera.eu\/pt_br\/wp-json\/wp\/v2\/calculator\/100181\/revisions"}],"predecessor-version":[{"id":100496,"href":"https:\/\/vibromera.eu\/pt_br\/wp-json\/wp\/v2\/calculator\/100181\/revisions\/100496"}],"wp:attachment":[{"href":"https:\/\/vibromera.eu\/pt_br\/wp-json\/wp\/v2\/media?parent=100181"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vibromera.eu\/pt_br\/wp-json\/wp\/v2\/categories?post=100181"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vibromera.eu\/pt_br\/wp-json\/wp\/v2\/tags?post=100181"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}