Since the vector forces applied to the center plate are normal to the surface, is there a lateral/shear force when sliding the center plate in and out?

I have tried to do this. I have no access to plates thick enough with rounded edges to prevent corona discharge nor a holder to get the plates close enough without the sheets being pulled into contact. If there is some lateral force then there would be an equation and no discussion or equation has been found so I am hoping someone here would know and be kind enough to share this information.

Thanks!