Designers / Molders questions and issues

The upcoming Structural Plastics conference will feature a panel discussion including a number of designers and plastic molders. The panel’s working title is “Molders are from Mars, Designers are from Venus.” The idea is that molders / manufacturers and designers need to work together, but often have a hard time doing so.
I’m soliciting input for possible discussion topics for this panel. What are the issues that designers face when working with a plastics fabricator? How can the two sides better work together?

The real issue is that manufacturers and fabricators who cannot offer additional services beyond the factory (including design) are already seeing their business flee to less expensive overseas operations. Are designers currently working with manufacturers as peers to expand the offerings on each side?

Are there other ways that designers find it hard to work with molders and fabricators? Please post suggested discussion items here. You can also email with your replies.

Actually, I work as an industrial designer for a mass-market plastic, consumer product manufacturer. Whew, long description. Basically, we make inexpensive products to be sold at Wally World, Target and other discount stores. Upon realizing that design is actually important (go figure), they hired in a full-time designer (me.)
Since the position is new, some people have a difficult time of understanding how little or much I know about certain aspects of design, especially when it comes to injection molding.
When I started here, I did not know about these things:

  1. Sinks caused by a large mass of material
  2. Complex parting lines, undercuts, intentional undercuts, etc.
  3. Cooling time
  4. Ejector pins
  5. Gates
  6. Coring of material
  7. Gas assist

Lots of other stuff, but once a designer has a grasp on how these things really play out on the production floor, then they can design well thought-out products.