MDF Project Questions

I have yet another project where I need to glue together many sheets (4'x8') of 3/4" MDF for a mold that I am making. My question is there a better, quicker, more efficient way to glue the MDF boards and get a good bond other than using a paint roller and wood glue?

I should note that because of the size, weight and number of pieces i am unable to clamp them traditionally so i am screwing the boards together to hold them until the glue dries, then i remove the screws and add the next layer. I have to do this with about 4 sheets of MDF each and once finished there will be about 15 of these that will be assembled into the full stacked mold.