I think the part is too think to allow you to pack out air bubbles but they may be formed due to too little packing pressure/sink bubbles. The only way to know is to heat plastic and if they pop, trapped air. If not the molten resin fills the hole.
To mold this you need a weight blender setup for such particles and a wear hardened screw and barrel. I also think tge compression ratio will need to be lower than a standard IM to protect the wood chips.
BTW what is the resin? The resin may not be properly dried or processed.
Rick