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58 DESIGN007 MAGAZINE I FEBRUARY 2022 well as their ability to offer protection against chemicals and high temperatures. eir use enables components to be protected against dust, moisture, and short circuits, and as stan- dard epoxy resins have better thermal conduc- tivity than air, they provide more efficient dis- sipation of heat from components, prolonging service life. Today there are a wide range of different epoxy-based resin systems available, offering a comprehensive range of different properties. A range of different cure speeds and cured properties can be obtained using different hardeners; amines, amine modified polymers and polyamides are all available. Some reac- tions can be very fast, and also very exothermic, leading to the possibility of a runaway reac- tion, particularly with large potting volumes. is can be mitigated by modifying the hard- ener or by using a filler, which will help absorb the heat of reaction and can oen help achieve flame retardant properties. It is important to note that the temperature at which a resin is cured will affect not only its cure speed, but also the quality of the end result. For example, post curing epoxy resins can oen improve the glass transition temperative, so it is important to carry out some trials before committing to a specific cure profile. One of our newest epoxy resins is a highly thermally conductive resin with low viscosity, ideal for potting cells within electric vehicle batteries. e UL94 V-0 approved epoxy pot- ting compound can withstand long durations at high temperatures and can assist with securing cells in place whilst dissipating the heat away to the surroundings. is particular epoxy resin creates a protective shield around the battery and enables strong adhesion, high tempera- ture resistance, and retention of characteristics throughout the thermal cycling process. is epoxy resin portfolio includes a vari- ety of clear, opaque, one- and two-part prod- ucts with a host of useful properties to meet most requirements from potting and sealing to dipping, including exceptional electri- cal and thermal characteristics, flame retar- dancy, and resistance to chemicals and fuels. Optically clear resins may be desirable for applications such as LED lighting fixtures, as the cured resin will obviously need to retain its clarity for the life of the unit. Colourless resins are also useful for prototyping appli- cations as the encapsulated components are easily viewed during and aer environmental and mechanical testing. On the other hand, coloured/opaque potting and encapsulation resins conceal what lies beneath the encapsu- lant surface, providing an effective foil against counterfeiters or those wishing to copy a cir- cuit layout, helping you to protect your intel- lectual property. Polyurethane Resins While epoxy resins are hard encapsulants when cured, polyurethane resins are typi- cally elastomeric—more rubber-like—in their cured state, which is particularly useful if the circuit to be potted contains delicate compo- nents. Like epoxy resins, polyurethane resins provide chemical, dust, and moisture resis- tance, as well as excellent electrical insulation and good adhesion to most substrates, both metal and plastic. Unlike their epoxy counter- parts, polyurethanes have a lower exotherm during cure, even for fast cure systems. Poly- urethane resins typically have a lower contin- uous operating temperature range and should not be allowed to rise above 130°C for the majority of its lifetime. Today there are a wide range of different epoxy- based resin systems available, offering a comprehensive range of different properties.