{"id":15849,"date":"2026-02-03T15:08:09","date_gmt":"2026-02-03T14:08:09","guid":{"rendered":"https:\/\/www.ptfe-felis.com\/viscosity\/"},"modified":"2026-08-17T16:02:28","modified_gmt":"2026-08-17T14:02:28","slug":"viscosity","status":"publish","type":"page","link":"https:\/\/www.ptfe-felis.com\/en\/viscosity\/","title":{"rendered":"Viscosity"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-page\" data-elementor-id=\"15849\" class=\"elementor elementor-15849\">\n\t\t\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-ef78989 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"ef78989\" data-element_type=\"section\" data-e-type=\"section\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-50 elementor-top-column elementor-element elementor-element-319c72a\" data-id=\"319c72a\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-3c3d500 elementor-widget elementor-widget-heading\" data-id=\"3c3d500\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h1 class=\"elementor-heading-title elementor-size-default\">Viscosity<\/h1>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-a9bd9ec elementor-widget elementor-widget-text-editor\" data-id=\"a9bd9ec\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p><strong>Last updated:\u00a0<\/strong>02\/2026<strong>\u00a0| Written by:\u00a0<\/strong>Content Team<strong>\u00a0| Reviewed by:<\/strong> <a style=\"font-weight: bold; color: white;\" href=\"https:\/\/www.ptfe-felis.com\/federico-lipparini\/\">Federico Lipparini<\/a><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6589be0 elementor-widget__width-initial elementor-widget-tablet__width-initial elementor-align-left elementor-widget elementor-widget-button\" data-id=\"6589be0\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<div class=\"elementor-button-wrapper\">\n\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm\" href=\"https:\/\/www.ptfe-felis.com\/en\/contatta-ptfe-felis\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\"><b>Contact<\/b><\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t<div class=\"elementor-column elementor-col-50 elementor-top-column elementor-element elementor-element-569156c\" data-id=\"569156c\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-0d40d34 elementor-widget__width-initial elementor-widget elementor-widget-image\" data-id=\"0d40d34\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img fetchpriority=\"high\" decoding=\"async\" width=\"233\" height=\"300\" src=\"https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2026\/02\/viscosity-233x300.png\" class=\"attachment-medium size-medium wp-image-18255\" alt=\"viscosity\" srcset=\"https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2026\/02\/viscosity-233x300.png 233w, https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2026\/02\/viscosity-796x1024.png 796w, https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2026\/02\/viscosity-768x988.png 768w, https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2026\/02\/viscosity-1194x1536.png 1194w, https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2026\/02\/viscosity.png 1555w\" sizes=\"(max-width: 233px) 100vw, 233px\" title=\"\">\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-97522b4 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"97522b4\" data-element_type=\"section\" data-e-type=\"section\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-33 elementor-top-column elementor-element elementor-element-cad5f8c\" data-id=\"cad5f8c\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-7de0f47 elementor-widget elementor-widget-image\" data-id=\"7de0f47\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2025\/09\/ISO-1-300x300.png\" class=\"attachment-medium size-medium wp-image-8727\" alt=\"ISO\" srcset=\"https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2025\/09\/ISO-1-300x300.png 300w, https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2025\/09\/ISO-1-150x150.png 150w, https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2025\/09\/ISO-1.png 500w\" sizes=\"(max-width: 300px) 100vw, 300px\" title=\"\">\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6755929 elementor-widget elementor-widget-heading\" data-id=\"6755929\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\"><b>ISO<\/b><\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-741fa8e elementor-widget elementor-widget-text-editor\" data-id=\"741fa8e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Organizzazione Internazionale per la Standardizzazione<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t<div class=\"elementor-column elementor-col-33 elementor-top-column elementor-element elementor-element-eb4001c\" data-id=\"eb4001c\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-afb8304 elementor-widget elementor-widget-image\" data-id=\"afb8304\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2025\/09\/FDA-2-300x300.png\" class=\"attachment-medium size-medium wp-image-8740\" alt=\"FDA\" srcset=\"https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2025\/09\/FDA-2-300x300.png 300w, https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2025\/09\/FDA-2-150x150.png 150w, https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2025\/09\/FDA-2.png 500w\" sizes=\"(max-width: 300px) 100vw, 300px\" title=\"\">\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-f019286 elementor-widget elementor-widget-heading\" data-id=\"f019286\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\"><b>FDA<\/b><\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-016db1b elementor-widget elementor-widget-text-editor\" data-id=\"016db1b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Amministrazione per Alimenti e Farmaci<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t<div class=\"elementor-column elementor-col-33 elementor-top-column elementor-element elementor-element-3fc6dbd\" data-id=\"3fc6dbd\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-2af7892 elementor-widget elementor-widget-image\" data-id=\"2af7892\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2025\/09\/RoHS-1-300x300.png\" class=\"attachment-medium size-medium wp-image-8748\" alt=\"RoHS\" srcset=\"https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2025\/09\/RoHS-1-300x300.png 300w, https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2025\/09\/RoHS-1-150x150.png 150w, https:\/\/www.ptfe-felis.com\/wp-content\/uploads\/2025\/09\/RoHS-1.png 500w\" sizes=\"(max-width: 300px) 100vw, 300px\" title=\"\">\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-5b510e9 elementor-widget elementor-widget-heading\" data-id=\"5b510e9\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\"><b>RoHS<\/b><\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-89c9e23 elementor-widget elementor-widget-text-editor\" data-id=\"89c9e23\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Restrizione delle Sostanze Pericolose<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-1631d82 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"1631d82\" data-element_type=\"section\" data-e-type=\"section\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-8fa2ca1\" data-id=\"8fa2ca1\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-86de49a elementor-widget elementor-widget-hfe-breadcrumbs-widget\" data-id=\"86de49a\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"hfe-breadcrumbs-widget.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<nav aria-label=\"Breadcrumb\"><ul class=\"hfe-breadcrumbs hfe-breadcrumbs-show-home\"><li class=\"hfe-breadcrumbs-item hfe-breadcrumbs-first\"><span class=\"hfe-breadcrumbs-home-icon\"><i aria-hidden=\"true\" class=\"fas fa-home\"><\/i><\/span><a href=\"https:\/\/www.ptfe-felis.com\/en\/\"><span class=\"hfe-breadcrumbs-text\">Pagina Iniziale<\/span><\/a><\/li><\/ul><\/nav>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-7c74e9c elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"7c74e9c\" data-element_type=\"section\" data-e-type=\"section\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-c867b48\" data-id=\"c867b48\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-fa47954 elementor-widget elementor-widget-text-editor\" data-id=\"fa47954\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p><span style=\"font-weight: 400;\">Viscosity is one of the most fundamental properties of fluids, describing their resistance to flow under applied forces. It plays a critical role across a wide range of disciplines, including chemistry, chemical engineering, materials science, mechanical engineering, and industrial processing. The concept of viscosity is not only essential for understanding how liquids and gases move but also crucial for the design of equipment such as pumps, pipelines, mixers, and lubrication systems.<\/span><\/p><p><span style=\"font-weight: 400;\">In practical terms, viscosity tells us how \u201cthick\u201d or \u201cthin\u201d a fluid is. For instance, honey flows slowly because it has high viscosity, whereas water flows easily due to its low viscosity. In industrial and laboratory applications, controlling viscosity ensures the proper mixing, coating, and transport of fluids, ranging from oils and polymers to food products and pharmaceuticals.<\/span><\/p><div style=\"margin: 40px 0; padding: 30px; background: #2c2cf6; border-radius: 8px; text-align: center;\"><h3 style=\"margin: 0 0 10px 0; font-size: 22px; color: #ffffff;\"><strong>Request Your PTFE Quote<\/strong><\/h3><p style=\"margin: 0 0 20px 0; font-size: 16px; color: #ffffff;\"><strong>Worldwide delivery and certified PTFE products.<\/strong><\/p><p><a style=\"display: inline-block; padding: 14px 28px; background: white; color: #000000; text-decoration: none; font-size: 16px; font-weight: 600; border-radius: 6px;\" href=\"https:\/\/www.ptfe-felis.com\/en\/contact-ptfe-felis\/\" target=\"_blank\" rel=\"follow noopener\">Get a Free Quote<br \/><\/a><\/p><\/div><h2><b>1. Definition of Viscosity<\/b><\/h2><p><span style=\"font-weight: 400;\">Viscosity is formally defined as the <\/span><b>internal friction of a fluid<\/b><span style=\"font-weight: 400;\"> that resists motion when a force is applied. It arises due to molecular interactions within the fluid: molecules closer to a moving surface drag against the fluid above them, creating resistance.<\/span><\/p><h3><b>Key Points:<\/b><\/h3><ul><li style=\"font-weight: 400;\" aria-level=\"1\"><b>SI Unit:<\/b><span style=\"font-weight: 400;\"> Pascal-second (Pa\u00b7s)<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Common Unit:<\/b><span style=\"font-weight: 400;\"> Centipoise (cP), where 1 cP = 0.001 Pa\u00b7s<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Reference:<\/b><span style=\"font-weight: 400;\"> Water at 20\u00b0C has a viscosity of approximately 1 cP, while honey can exceed 10,000 cP.<\/span><\/li><\/ul><p><span style=\"font-weight: 400;\">For Newtonian fluids fluids whose viscosity remains constant regardless of applied stress the relationship between shear stress (\u03c4) and shear rate (\u03b3\u0307) is given by:<\/span><\/p><p><span style=\"font-weight: 400;\">\u03b7=\u03c4\u03b3\u02d9\\eta = \\frac{\\tau}{\\dot{\\gamma}}\u03b7=\u03b3\u02d9\u200b\u03c4\u200b<\/span><\/p><p><span style=\"font-weight: 400;\">Where:<\/span><\/p><ul><li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">\u03b7 = dynamic viscosity<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">\u03c4 = shear stress applied to the fluid<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">\u03b3\u0307 = shear rate (rate of deformation)<\/span><\/li><\/ul><p><span style=\"font-weight: 400;\">This formula highlights that viscosity is essentially the ratio of the force needed to move a fluid layer to the rate at which it moves.<\/span><\/p><h2><b>2. Types of Viscosity<\/b><\/h2><p><span style=\"font-weight: 400;\">Viscosity can be categorized into several types based on measurement and behavior.<\/span><\/p><h3><b>2.1 Dynamic (Absolute) Viscosity<\/b><\/h3><p><span style=\"font-weight: 400;\">Dynamic viscosity measures a fluid\u2019s resistance to shear under an applied force. It describes how \u201csticky\u201d the fluid is and is measured in Pa\u00b7s or cP. Dynamic viscosity is particularly relevant for applications involving <a href=\"https:\/\/www.ptfe-felis.com\/en\/lubricant\/\">lubricants<\/a>, oils, and polymer melts.<\/span><\/p><h3><b>2.2 Kinematic Viscosity<\/b><\/h3><p><span style=\"font-weight: 400;\">Kinematic viscosity is the ratio of dynamic viscosity to fluid density:<\/span><\/p><p><span style=\"font-weight: 400;\">\u03bd=\u03b7\u03c1\\nu = \\frac{\\eta}{\\rho}\u03bd=\u03c1\u03b7\u200b<\/span><\/p><p><span style=\"font-weight: 400;\">Where \u03bd = kinematic viscosity, \u03b7 = dynamic viscosity, and \u03c1 = density. It is measured in m\u00b2\/s or centistokes (cSt) and is widely used in fluid dynamics and lubrication calculations because it accounts for fluid weight in motion.<\/span><\/p><h3><b>2.3 Apparent Viscosity<\/b><\/h3><p><span style=\"font-weight: 400;\">Apparent viscosity applies to <\/span><b>non-Newtonian fluids<\/b><span style=\"font-weight: 400;\">, whose viscosity changes with shear rate. These fluids do not obey Newton\u2019s law of viscosity. Examples include:<\/span><\/p><ul><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Shear-thinning fluids:<\/b><span style=\"font-weight: 400;\"> Ketchup, paints viscosity decreases under agitation or stress.<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Shear-thickening fluids:<\/b><span style=\"font-weight: 400;\"> Cornstarch in water viscosity increases when stressed.<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Bingham plastics:<\/b><span style=\"font-weight: 400;\"> Toothpaste requires a threshold stress to begin flowing.<\/span><\/li><\/ul><h2><b>3. Factors Affecting Viscosity<\/b><\/h2><p><span style=\"font-weight: 400;\">Viscosity is influenced by multiple physical and chemical factors:<\/span><\/p><table><tbody><tr><td><b>Factor<\/b><\/td><td><b>Effect<\/b><\/td><\/tr><tr><td><span style=\"font-weight: 400;\">Temperature<\/span><\/td><td><span style=\"font-weight: 400;\">Increasing temperature decreases viscosity for liquids; increases for gases<\/span><\/td><\/tr><tr><td><span style=\"font-weight: 400;\">Pressure<\/span><\/td><td><span style=\"font-weight: 400;\">High pressure slightly increases viscosity in liquids<\/span><\/td><\/tr><tr><td><span style=\"font-weight: 400;\">Composition<\/span><\/td><td><span style=\"font-weight: 400;\"><a href=\"https:\/\/www.ptfe-felis.com\/en\/solvents\/\">Solvents<\/a>, additives, and polymer concentration modify viscosity<\/span><\/td><\/tr><tr><td><span style=\"font-weight: 400;\">Shear rate<\/span><\/td><td><span style=\"font-weight: 400;\">Non-Newtonian fluids show shear-thinning or shear-thickening behavior<\/span><\/td><\/tr><\/tbody><\/table><h3><b>Temperature<\/b><\/h3><p><span style=\"font-weight: 400;\">In liquids, higher temperatures reduce intermolecular attractions, making the fluid flow more easily. For gases, higher temperatures increase molecular collisions, raising viscosity.<\/span><\/p><h3><b>Pressure<\/b><\/h3><p><span style=\"font-weight: 400;\">While pressure has a minimal effect on most liquids at moderate conditions, extreme pressures such as those in hydraulic systems can slightly increase viscosity.<\/span><\/p><h3><b>Composition<\/b><\/h3><p><span style=\"font-weight: 400;\">The presence of dissolved solids, <a href=\"https:\/\/www.ptfe-felis.com\/en\/polymers\/\">polymers<\/a>, or additives can either increase or decrease viscosity. For example, polymer solutions like polyvinyl alcohol become more viscous as concentration increases.<\/span><\/p><h2><b>4. Viscosity in Different Fluids<\/b><\/h2><h3><b>4.1 Liquids<\/b><\/h3><p><span style=\"font-weight: 400;\">Viscosity varies widely among liquids:<\/span><\/p><ul><li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Honey &gt; Glycerol &gt; Water &gt; Ethanol<\/span><\/li><\/ul><p><span style=\"font-weight: 400;\">Generally, liquids become <\/span><b>less viscous with increasing temperature<\/b><span style=\"font-weight: 400;\">, which is crucial in processes like hot lubrication or syrup production.<\/span><\/p><h3><b>4.2 Gases<\/b><\/h3><p><span style=\"font-weight: 400;\">Gas viscosity behaves differently:<\/span><\/p><ul><li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Air &lt; Oxygen &lt; Carbon Dioxide<\/span><\/li><\/ul><p><span style=\"font-weight: 400;\">Here, viscosity <\/span><b>increases with temperature<\/b><span style=\"font-weight: 400;\"> because faster-moving molecules collide more frequently, resisting flow.<\/span><\/p><h3><b>4.3 Non-Newtonian Fluids<\/b><\/h3><p><span style=\"font-weight: 400;\">Many industrial fluids are non-Newtonian:<\/span><\/p><ul><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Shear-thinning:<\/b><span style=\"font-weight: 400;\"> Paints, ketchup, latex viscosity decreases under agitation.<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Shear-thickening:<\/b><span style=\"font-weight: 400;\"> Cornstarch suspensions viscosity increases under stress.<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Bingham plastics:<\/b><span style=\"font-weight: 400;\"> Toothpaste, cosmetic gels do not flow until a critical stress is applied.Understanding non-Newtonian behavior is essential in food processing, pharmaceuticals, and coatings industries.<\/span><\/li><\/ul><h2><b>5. Industrial Applications of Viscosity<\/b><\/h2><p><span style=\"font-weight: 400;\">Viscosity impacts efficiency, safety, and product quality in many industries.<\/span><\/p><h3><b>5.1 Lubricants<\/b><\/h3><ul><li style=\"font-weight: 400;\" aria-level=\"1\"><b>High-viscosity oils<\/b><span style=\"font-weight: 400;\"> form a protective film, reducing wear in high-pressure bearings.<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Low-viscosity oils<\/b><span style=\"font-weight: 400;\"> are preferred in cold conditions to ensure fluidity and quick start-up.<\/span><\/li><\/ul><h3><b>5.2 Polymer Processing<\/b><\/h3><ul><li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Viscosity determines flow behavior in extrusion, injection molding, and coating operations.<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\"><a href=\"https:\/\/www.ptfe-felis.com\/en\/what-is-ptfe\/\">PTFE<\/a>, for instance, has extremely high melt viscosity, preventing conventional injection molding.<\/span><\/li><\/ul><h3><b>5.3 Chemical Processing<\/b><\/h3><ul><li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Viscosity affects <\/span><b>pumping efficiency, mixing, and heat transfer<\/b><span style=\"font-weight: 400;\">. Accurate viscosity data ensures proper equipment design and energy efficiency.<\/span><\/li><\/ul><h3><b>5.4 Food Industry<\/b><\/h3><ul><li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Sauce, syrup, and beverage consistency depend on controlled viscosity. Shear-thinning behavior is exploited in ketchup or chocolate manufacturing to improve pourability.<\/span><\/li><\/ul><h3><b>5.5 Pharmaceutical Industry<\/b><\/h3><ul><li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Syrups, gels, creams, and ointments require precise viscosity for stability, controlled release, and ease of administration.<\/span><\/li><\/ul><h2><b>6. Measurement of Viscosity<\/b><\/h2><p><span style=\"font-weight: 400;\">Several methods exist to measure viscosity depending on the fluid type:<\/span><\/p><ul><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Capillary Viscometer (Ostwald Viscometer):<\/b><span style=\"font-weight: 400;\"> Measures flow time of a fluid through a narrow tube; suitable for Newtonian liquids.<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Rotational Viscometer:<\/b><span style=\"font-weight: 400;\"> Measures torque required to rotate a spindle in the fluid; suitable for low and high viscosity fluids.<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Falling Sphere Viscometer:<\/b><span style=\"font-weight: 400;\"> Viscosity is inferred from the time taken for a sphere to fall through the fluid.<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><b>Rheometer:<\/b><span style=\"font-weight: 400;\"> Measures viscosity across a range of shear rates; essential for non-Newtonian fluids.<\/span><\/li><\/ul><p><span style=\"font-weight: 400;\">Accurate measurement is critical in research, quality control, and industrial operations.<\/span><\/p><h2><b>7. Importance of Viscosity<\/b><\/h2><p><span style=\"font-weight: 400;\">Viscosity is not merely an abstract property; it directly influences the behavior and performance of fluids:<\/span><\/p><ul><li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Determines <\/span><b>flow behavior<\/b><span style=\"font-weight: 400;\"> under mechanical stress.<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Affects <\/span><b>energy consumption<\/b><span style=\"font-weight: 400;\"> in pumping and mixing systems.<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Influences <\/span><b>coating thickness, heat transfer, and lubrication efficiency<\/b><span style=\"font-weight: 400;\">.<\/span><\/li><li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Guides the <\/span><b>design of industrial processes<\/b><span style=\"font-weight: 400;\">, from chemical reactors to food processing lines.<\/span><\/li><\/ul><p><span style=\"font-weight: 400;\">Understanding viscosity allows engineers to select materials, optimize processes, and predict fluid performance under different operating conditions.<\/span><\/p><h2><b>Conclusion<\/b><\/h2><p><span style=\"font-weight: 400;\">Viscosity is a fundamental fluid property governing flow, processing, and performance in a wide range of applications. From lubricants and polymers to food and pharmaceuticals, knowing how viscosity behaves under various conditions is essential for engineers, scientists, and industrial designers. By controlling viscosity, one can enhance product consistency, reduce energy consumption, and optimize equipment efficiency. Whether dealing with Newtonian or non-Newtonian fluids, accurate measurement and careful analysis of viscosity are critical for safe, efficient, and high-quality industrial processes.<\/span><\/p><h2><b>Frequently Asked Questions (FAQs)<\/b><\/h2><p><b>Q1: What is the difference between dynamic and kinematic viscosity?<\/b><b><br \/><\/b> <b>A:<\/b><span style=\"font-weight: 400;\"> Dynamic viscosity measures resistance to flow under applied force, while kinematic viscosity accounts for fluid density (\u03bd = \u03b7\/\u03c1).<\/span><\/p><p><b>Q2: Why does temperature affect viscosity?<\/b><b><br \/><\/b> <b>A:<\/b><span style=\"font-weight: 400;\"> Higher temperatures weaken intermolecular forces in liquids, lowering viscosity. In gases, higher temperatures increase molecular collisions, raising viscosity.<\/span><\/p><p><b>Q3: What is a non-Newtonian fluid?<\/b><b><br \/><\/b> <b>A:<\/b><span style=\"font-weight: 400;\"> A fluid whose viscosity changes with shear rate, such as ketchup, toothpaste, or certain polymer solutions.<\/span><\/p><p><b>Q4: How is viscosity measured?<\/b><b><br \/><\/b> <b>A:<\/b><span style=\"font-weight: 400;\"> Using capillary viscometers, rotational viscometers, falling sphere viscometers, or rheometers.<\/span><\/p><p><b>Q5: Why is viscosity important in industrial applications?<\/b><b><br \/><\/b> <b>A:<\/b><span style=\"font-weight: 400;\"> It affects flow, heat transfer, pumping efficiency, lubrication, coating uniformity, and product stability.<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-92a813b elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"92a813b\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-1a4da82\" data-id=\"1a4da82\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-af8fbdd elementor-widget elementor-widget-heading\" data-id=\"af8fbdd\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Related Post<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c0bce62 elementor-widget elementor-widget-text-editor\" data-id=\"c0bce62\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<ol><li><a href=\"https:\/\/www.ptfe-felis.com\/en\/electrical-insulation\/\">What is <span data-sheets-root=\"1\">electrical insulation?<\/span><\/a><\/li><li><a href=\"https:\/\/www.ptfe-felis.com\/en\/why-ptfe-is-chemically-inert-at-molecular-level\/\"><span data-sheets-root=\"1\">Why PTFE is chemically inert at molecular level<\/span><\/a><\/li><li><a href=\"https:\/\/www.ptfe-felis.com\/en\/ptfe-molecular-structure-and-carbon-fluorine-bond\/\"><span data-sheets-root=\"1\">What is PTFE molecular structure and carbon\u2013fluorine bond?<\/span><\/a><\/li><li><a href=\"https:\/\/www.ptfe-felis.com\/en\/top-chemical-hose-manufacturers-in-india\/\"><span data-sheets-root=\"1\">Top Chemical Hose Manufacturers in India<\/span><\/a><\/li><\/ol>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Viscosity Last updated:\u00a002\/2026\u00a0| Written by:\u00a0Content Team\u00a0| Reviewed by: Federico Lipparini Contact ISO Organizzazione Internazionale per la Standardizzazione FDA Amministrazione per Alimenti e Farmaci RoHS Restrizione delle Sostanze Pericolose Pagina Iniziale Viscosity is one of the most fundamental properties of fluids, describing their resistance to flow under applied forces. It plays a critical role across a [&hellip;]<\/p>\n","protected":false},"author":8,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-15849","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.ptfe-felis.com\/en\/wp-json\/wp\/v2\/pages\/15849","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ptfe-felis.com\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.ptfe-felis.com\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.ptfe-felis.com\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ptfe-felis.com\/en\/wp-json\/wp\/v2\/comments?post=15849"}],"version-history":[{"count":30,"href":"https:\/\/www.ptfe-felis.com\/en\/wp-json\/wp\/v2\/pages\/15849\/revisions"}],"predecessor-version":[{"id":45648,"href":"https:\/\/www.ptfe-felis.com\/en\/wp-json\/wp\/v2\/pages\/15849\/revisions\/45648"}],"wp:attachment":[{"href":"https:\/\/www.ptfe-felis.com\/en\/wp-json\/wp\/v2\/media?parent=15849"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}