IS THERE AN ELECTRICALLY CONDUCTIVE SYSTEM THAT CAN BE SPRAY COATED FOR SUPERIOR EMI/RFI SHIELDING?


Customer’s Application

The customer that manufactures radio devices for military applications is looking for a sprayable coating to protect the device from electromagnetic interference. It is also important for the coating to provide an effective barrier against moisture.

Application Discussion

In order to recommend the right solution, our technical expert needs to find out answers to certain questions pertaining to the customer’s application:
1. What level of shielding effectiveness is required in your application?
2. Will you be performing any humidity testing? At what temperature, moisture level and for how long does the coating need to withstand the testing?
3. What are the minimum and maximum temperatures that the coating will be exposed to?
4. What viscosity are you looking for?

Product Recommendation

Based on answers to the above questions, Kohesi Bond’s technical expert recommended our product KB-SS-SIL. KB-SS-SIL is a one component, room temperature curing sodium silicate based system. It offers superior electrical conductivity (volume resistivity < 0.001 ohm-cm). Shielding effectiveness is measured by attenuation, which refers to the difference in an electromagnetic signal’s intensity before and after shielding. Achieving shielding at higher frequencies is extremely challenging. However, as seen in the table below, KB-SS-SIL offers phenomenal shielding against electromagnetic and radio frequency interference, even at higher frequencies. Additionally, it has proven to be an excellent moisture barrier that can withstand extremely high temperatures, up to 370°C. It offers a flowable paste like viscosity, which makes it easy to spray on any substrate using an appropriate equipment. It is a water based system, making it relatively non-toxic. Our customer successfully tested KB-SS-SIL in their application and got excellent results.

FREQUENCY

SHIELDING EFFECTIVENESS

1 – 2 GHZ

95 – 105 dBs

2 – 15 GHz

95 – 78 dBs

18 GHz

60 dBs