ALTERNATIVE METHODS TO ENABLE THE POWDER PRIMING OF SMC

Our previous work has shown that the newly developed SMC systems are powder primer ready in straight through operations. However, after an extended stoppage in the operation such as July shutdown, the success of the powder application depends on the severity of temperature ramp in the oven. To overcome this issue, in this work, an alternative short term preheating is proposed after any long term humidity exposure in the plant. It was observed that using the newly developed experimental low moisture SMC/conductive coating systems, only four minutes of preheating in the oven at 180°C, or three minutes of IR exposure was sufficient to enable powder priming in a plant simulation without popping. The preheating approach also allowed the use of conventional conductive coating on the experimental low moisture SMC without compromising its powder capability. Similarly, using this method, it was possible to powder prime conventional SMC in combination with the experimental conductive coating with no popping. However, the preheating method could not benefit the combination of conventional-SMC/conventional-conductive-coating.