{"id":4816,"date":"2020-05-09T11:56:17","date_gmt":"2020-05-09T11:56:17","guid":{"rendered":"https:\/\/resin-expert.com\/?p=4816"},"modified":"2024-06-03T17:50:39","modified_gmt":"2024-06-03T17:50:39","slug":"polyurethane-resin","status":"publish","type":"post","link":"https:\/\/resin-expert.com\/en\/guide\/polyurethane-resin","title":{"rendered":"Polyurethane Resin Guide \u2013 Everything you need to Know"},"content":{"rendered":"

If you want to work with resin, you are spoilt for choice. There are several different resins available on the market, and each type has its advantages and disadvantages – including polyurethane casting resin. In our Polyurethane Resin Guide, we give you the most essential polyurethane casting resin properties and tell you what to look out for when buying polyurethane.<\/strong><\/p>\n

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What is Polyurethane Resin?<\/h2>\n

Generally speaking, polyurethanes are synthetic resins or plastics that result from a polyaddition reaction between dialcohols or polyols and polyisocyanates.<\/p>\n

Polyurethane casting resin has a wide range of properties that vary from application to application and cover a wide range of possibilities. Thus, not only thermoplastics but also thermosets and elastomers are produced from it.<\/p>\n

In general, the casting resin consists of a two-component system of resin and hardener, which hardens after mixing through a chemical reaction. PU casting resins can, just like epoxy resin and polyester resin<\/strong><\/a>, be combined with various additives as well as filling materials or colorants. This gives them the desired properties. For example, the user can add an inhibitor to the resin to increase the so-called pot life, i.e., the processing time. As a result, this can be made very variable to suit any application.<\/p>\n

There are also color pigments and fluorescent dyes that can give the polyurethane resin a specific color. This allows you to adapt the resin to your own requirements. Examples of fillers are, among others, cotton flocks, glass fibers, mineral fillers, and lightweight fillers. With these, the user can influence properties such as mechanical strength, stiffness, or surface hardness.<\/p>\n

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Advantages and Disadvantages of Polyurethane Resin<\/h2>\n

Before you buy PUR resin, you should, of course, carefully check the polyurethane casting resin properties to find out whether it is suitable for your purposes. In general, PU cast resin is a very pleasant material with many advantages and only a few disadvantages.<\/p>\n

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Pros<\/strong><\/span><\/p>\n

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  • <\/i> It has excellent flow properties and can, therefore, be easily mixed and processed<\/strong><\/li>\n
  • <\/i> However, its viscosity is not too high, so that it can be optimally cast and shaped<\/strong><\/li>\n
  • <\/i> It hardens quickly and its demolding time is very short<\/strong><\/li>\n
  • <\/i> It has a good filling capacity<\/strong><\/li>\n
  • <\/i> It can also be used to produce very small and thin-walled models, which nevertheless exhibit high stability<\/strong><\/li>\n
  • <\/i> It is suitable as electrical encapsulant<\/strong><\/li>\n
  • <\/i> You can mix in a wide variety of additives such as inhibitors, filling materials, and color pastes<\/strong><\/li>\n
  • <\/i> There is only a small amount of shrinkage during curing<\/strong><\/li>\n
  • <\/i> It has a very high heat resistance after curing<\/strong><\/li>\n
  • <\/i> Depending on the composition, both elastomers and thermosetting plastics are available; the former can be joined together by vulcanization after curing<\/strong><\/li>\n<\/ul>\n<\/div>\n<\/div><\/div>
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    Cons<\/strong><\/span><\/p>\n

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    • <\/i> It has a high sensitivity to moisture, which can cause undesirable reactions such as foaming<\/strong><\/li>\n
    • <\/i> To become insensitive to UV light, certain additives are required<\/strong><\/li>\n
    • <\/i> It is not weldable after curing<\/strong><\/li>\n
    • <\/i> During curing, the styrene causes a strong odor and thus a potential health hazard<\/strong><\/li>\n
    • <\/i> The adhesive property of PU resin is less than that of epoxy resin<\/strong><\/li>\n<\/ul>\n

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      PU resins that have to be processed quickly, but at the same time can also be unmolded quickly, are generally called fast-casting resins. If you want to work with such a resin, you must, therefore, pay attention to the pot life, otherwise the material hardens too quickly, and you have to start again from the beginning. This can be seen as a disadvantage, but also as an advantage, because after all, it also results in it being quick to unmold.<\/p>\n

      If you want to buy polyurethane resin, you should also check the hardness level and whether it is suitable for your project. The degree of hardness is indicated in Shore and should be noted on the respective packaging. After curing, soft materials are indicated in Shore hardness A and harder materials in Shore hardness D. The former have a rubber-like consistency.<\/p>\n

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      Application Areas of PU Resin<\/h2>\n

      The areas of application for PU resin are incredibly diverse. <\/strong>Polyurethane casting resin is a fascinating material for both industry and the do-it-yourselfer.<\/p>\n

      For example, foams can be produced from PU, but also paints, adhesives, and coatings. However, PU also protects electronic assemblies from a wide range of environmental influences such as mechanical stress or moisture. Therefore, these are usually encapsulated.<\/p>\n

      But also for the production of damping and spring elements, casting tires, instrument transformers for medium and high voltage technology, drive elements as well as various wearing parts, the PU resin has become invaluable.<\/p>\n

      In contrast to the production of foam, where a reaction with water and the resulting foam formation is desired, in all other applications, the surfaces with which the liquid PU resin comes into contact should be completely dry. Otherwise, the polyurethane casting resin may lose its favorable properties.<\/p>\n

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      Floor Coatings<\/h3>\n

      Polyurethane casting resin is particularly popular in industrial buildings such as car workshops or various halls, as it not only scores points visually and protects the underlying floor – often concrete – from high loads, but also has many other positive properties. As a floor covering, it is abrasion-resistant and very elastic. It withstands not only high thermal but also mechanical loads and is easy to apply. Furthermore, it is not too cost-intensive.<\/p>\n