Polyurethane casting resins - individual casting compounds

Polyurethanes (also shortened to PUR or PU) are plastics or synthetic resins. Polyurethanes are usually used as 2-component materials consisting of resin and hardener. They can be formulated and used both as compact materials (open-cell or closed-cell) and in the form of foams.

Compact materials are primarily used to protect components in the electronics industry.

We are your experts for customized casting resin systems and can produce compounds with product properties ranging from hard to soft, from tough to brittle, from low viscosity to high viscosity/ sagg resistant, from very fast to slow curing, from hydrophilic to hydrophobic. It is also possible to incorporate special properties such as flame retardancy, thermal conduction or thermal insulation, compressibility and many more.

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Different applications with polyurethane

Chemical formula: Structure of a non-crosslinked polyurethane

Fig. 1 Structure of a non-crosslinked polyurethane

We all use products containing polyurethane on daily basis. A large number of chemical raw materials, additives, fillers and other aggregates make it possible to realize a wide range of application profiles. PU cast resins can be found in the furniture industry in the form of mattresses or upholstery, as well as in vehicle interiors. They are also indispensable in the shoe industry, especially in shoe soles. In the building materials sector, polyethane casting resins can be found in a wide variety of applications, either in floor coatings or in insulation and assembly foams. In all industries the use of polyurethane protective coatings represents a very broad and elementary field of application.

Chemically, polyurethanes are made up of polyols and isocyanates (Fig. 1), whereby polymers with varying degrees of cross-linking are generally sought. In contrast to hotmelt adhesives, these are not thermoplastic. A large number of industrial polyols (polyether, polyester, polybutadiene, etc.) and isocyanates are available for the production of polyurethanes, allowing a wide variety of products and properties to be customized, so to speak.

Another important chemical reaction of the isocyanate group is its reaction with water, which releases carbon dioxide and an amine. For this reason, when casting polyurethanes, especially for solid components, care must be taken to work under moisture free conditions as far as possible in order to achieve an optimum, bubble-free result. The addition of water-adsorbing fillers, so-called zeolites, can absorb residual moisture from the raw materials used, which makes application easier.

CO2 formation is used specifically in the formation of foams (insulation foams, mattresses, shoe soles) and pre-existing bubbles reinforce this effect further.

Through the formation of amines, NCO-terminated prepolymers can also cure with atmospheric moisture, making 1-component systems for sealants and adhesives possible.

Chemical formula of water - isocyanate reaction

Fig. 2: Water - isocyanate reaction

Polyurethane casting resins - individual casting compounds

Polyurethane casting resins - properties & product selection

Can't find a suitable product?

Different applications with polyurethane