{"version":"1.0","provider_name":"Bulldog Castors Blog","provider_url":"https:\/\/www.bulldogcastors.co.uk\/blog","title":"Polyurethane Caster Wheels Material Guide - Bulldog Castors Blog","type":"rich","width":600,"height":338,"html":"<blockquote class=\"wp-embedded-content\" data-secret=\"WMwPCoivvZ\"><a href=\"https:\/\/www.bulldogcastors.co.uk\/blog\/polyurethane-caster-wheels\/\">Polyurethane Caster Wheels Material Guide<\/a><\/blockquote><iframe sandbox=\"allow-scripts\" security=\"restricted\" src=\"https:\/\/www.bulldogcastors.co.uk\/blog\/polyurethane-caster-wheels\/embed\/#?secret=WMwPCoivvZ\" width=\"600\" height=\"338\" title=\"&#8220;Polyurethane Caster Wheels Material Guide&#8221; &#8212; Bulldog Castors Blog\" data-secret=\"WMwPCoivvZ\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" class=\"wp-embedded-content\"><\/iframe><script type=\"text\/javascript\">\n\/*! This file is auto-generated *\/\n!function(d,l){\"use strict\";var e=!1,o=!1;if(l.querySelector)if(d.addEventListener)e=!0;if(d.wp=d.wp||{},!d.wp.receiveEmbedMessage)if(d.wp.receiveEmbedMessage=function(e){var t=e.data;if(t)if(t.secret||t.message||t.value)if(!\/[^a-zA-Z0-9]\/.test(t.secret)){for(var r,a,i,s=l.querySelectorAll('iframe[data-secret=\"'+t.secret+'\"]'),n=l.querySelectorAll('blockquote[data-secret=\"'+t.secret+'\"]'),o=new RegExp(\"^https?:$\",\"i\"),c=0;c<n.length;c++)n[c].style.display=\"none\";for(c=0;c<s.length;c++)if(r=s[c],e.source===r.contentWindow){if(r.removeAttribute(\"style\"),\"height\"===t.message){if(1e3<(i=parseInt(t.value,10)))i=1e3;else if(~~i<200)i=200;r.height=i}if(\"link\"===t.message)if(a=l.createElement(\"a\"),i=l.createElement(\"a\"),a.href=r.getAttribute(\"src\"),i.href=t.value,o.test(i.protocol))if(i.host===a.host)if(l.activeElement===r)d.top.location.href=t.value}}},e)d.addEventListener(\"message\",d.wp.receiveEmbedMessage,!1),l.addEventListener(\"DOMContentLoaded\",t,!1),d.addEventListener(\"load\",t,!1);function t(){if(!o){o=!0;for(var e,t,r,a=-1!==navigator.appVersion.indexOf(\"MSIE 10\"),i=!!navigator.userAgent.match(\/Trident.*rv:11\\.\/),s=l.querySelectorAll(\"iframe.wp-embedded-content\"),n=0;n<s.length;n++){if(!(r=(t=s[n]).getAttribute(\"data-secret\")))r=Math.random().toString(36).substr(2,10),t.src+=\"#?secret=\"+r,t.setAttribute(\"data-secret\",r);if(a||i)(e=t.cloneNode(!0)).removeAttribute(\"security\"),t.parentNode.replaceChild(e,t);t.contentWindow.postMessage({message:\"ready\",secret:r},\"*\")}}}}(window,document);\n<\/script>\n","thumbnail_url":"https:\/\/www.bulldogcastors.co.uk\/blog\/wp-content\/uploads\/EDAPUFTP.jpg","thumbnail_width":413,"thumbnail_height":413,"description":"Polyurethane Caster Wheels &#8211; The Ultimate Material Polyurethane elastomers are a versatile synthetic polymer, invented back in the 1930\u2019s by Dr. Otto Bayer.\u00a0 Today over 12 Million metric tonnes are used worldwide annually and their application is broad, being used in such items as Polyurethane Caster Wheels, Automotive Bushes, Fork Lift Wheels, Foams, Shoe Soles, Coatings and Adhesives. All Polyurethanes are manufactured from the same basic elements.\u00a0 The elements Isocyanate and Polyol (Alcohol) are mixed in a chemical reaction to create the raw polyurethane material.\u00a0 The chemistry behind the manufacture is relatively complex and there are many different grades available. There are two types of Polyol which can be used to manufacture Polyurethane Material for Casters, Polyether Polypol and Polyester Polypol.\u00a0 Polyether Polypol is generally cheaper and has better water resistance. Polyurethane Caster Wheels hardness can be measured using both the \u201cShore A\u201d scale and \u201cShore D\u201d scale.\u00a0 Shore A is generally used for the softer polyurethanes, whilst Shore D is generally used for the harder materials.\u00a0 Generally Polyurethane Casters are manufactured towards the harder end of the scale, and hence the Shore D scale is commonly used. 30-50 Shore D is typical for Polyurethane Casters.\u00a0 To give a comparison, 90sh A is equivalent to 41sh D. From all the many grades of Polyurethane grades available, they all All fall into the following two categories: Thermoplastic Polyurethane (Abbreviated to \u201cTPU\u201d) &#8211;\u00a0 Thermoplastic Polyurethane generally comes in Pellet Form.\u00a0 As the Pellets are heated, they become fluid and can be moulded or formed into the required shape.\u00a0 This process does not change the molecular state of the Polyurethane, and therefore the material will melt if reheated and is therefore suitable for recycling. &nbsp; Thermoset Polyurethane (Abbreviated to \u201cPUR\u201d) \u2013 Thermoset Polyurethane typically comes in liquid form, which does not need to be heated. The Polyurethane Liquid is mixed with a curative and any additives to give required properties (such as hardness or increased abrasion resistant).\u00a0 Thermoset Polyurethane is commonly known as a \u201ctwo part\u201d material, where the two separate liquids are mixed together, which then set (cure).\u00a0 The curing process causes a chemical reaction where the molecular structure changes to a permanent state.\u00a0 The Product will cure at room temperature.\u00a0 Once formed, Thermoset Polyurethane will not melt if heated and cannot be reformed or recycled. &nbsp; Polyurethane Products, Such as Polyurethane Caster Wheels can be manufactured using a range of different techniques, including Open Moulding &#8211;\u00a0 This is where the two part polyurethane is mixed to give a uniform mixture.\u00a0 The mixture is then de-gassed (either by using heat or vacuum) and then poured into an open mould.\u00a0 The mixture sets relatively quickly, and it is therefore important that the process is conducted as quickly as possible and that the material is mixed in small batches to avoid wastage. Machine Casting \u2013 This is almost identical to the Open Moulding technique, however the whole process is conducting in a Casting Machine, saving time and providing a more consistent final product. Spraying &amp; Coating &#8211;\u00a0 This is a simple process where the polyurethane is sprayed onto a component to provide a coating of Polyurethane Injection Moulding \u2013 Generally only used for Thermoplastic materials, the Polyurethane Pellets are fed into a reciprocating injection moulding machine.\u00a0 The reciprocating screw is heated which in turn melts the Polyurethane, whilst at the same time feeding the liquid material through the machine and injected into a mould tool.\u00a0 The material is then left to cool and then removed from the mould. Machining &#8211;\u00a0 Most Polyurethane Grades can be machined using conventional methods, such as Milling, Turning, Drilling and Grinding, however special techniques are required for softer materials, typically below 50 Shore D.\u00a0 One Technique for softer materials is to freeze the material before machining to increase its hardness.\u00a0 It is possible to machine to relatively high tolerances when using hard polyurethane, in the region of +\/-0.1mm, which can be further improved by using a grinding process. &nbsp; Polyurethane Caster Wheels \u00a0 \u00a0 \u00a0\u00a0 Polyurethane is one of the most commonly used materials within the Caster Wheel Industry.\u00a0 It provides many of the characteristics of flexible rubber castors, such as Resilience, High Grip, Shock and Vibration Absorption, whilst also having many of the characteristics of hard Plastic or Nylon Castors such as Extreme Wear Resistance, High Load Capacity and Resistance to many Oils, Solvents and Cleaning Fluids. Polyurethane Casters can be manufactured from both Thermoplastic and Thermoset Polyurethanes, however most commonly the Thermoset materials are used due to their increased properties.\u00a0 The molecular changes during curing provide increased strength, wear resistance and material stability under heat. Polyurethane can be chemically or mechanical bonded to many materials such as Nylon, Polypropylene, Steel and Aluminium.\u00a0 This allows for a Polyurethane tread to be applied to a vast range of materials.\u00a0 The thickness of the tread will alter the wheels properties.\u00a0 A Think 5mm Coating will offer an extremely high load capacity, whereas a 20mm thickness tread will provide a high shock and impact absorption. Properties of Polyurethane Caster Wheels can include: Non-Marking Wheel protects Floors from Marking &amp; Scratches Resilient Wheel Tread provides Shock, Impact and Shock Absorption Resistant to many Oils, Solvents, Greases and Cleaning Fluids Resistant to Water upto 50 deg C Wear Resistance similar to Nylon and Steel Excellent Electrical Resistivity Low Noise Operation \u2013 Excellent for noise sensitive environments such as Offices, Schools and Hospitals High Load Capacity Available in a range of hardness\u2019 \u2013 allowing increased load capacity or higher grip and traction Available in almost an Colour providing pleasing aesthetic appearance (Red, Yellow and Orange are most common). Immune to Ozone and Oxygen, meaning the wheels will not crack or degrade if near sources of Ozone, such as near electrical equipment. Some Grades are Mould, Mildew and Fungus resistant, making ideal Caster Wheels for Food and Hospital environments. Weather Resistant, ideal for permanent outdoor use. &nbsp; Bulldog Castors Ltd Here at Bulldog Castors\u2122 we provide ourselves on providing first class engineering support and..."}