Mold Injection , What Kind of Shapes are possible

Hi Guys / Gals

I was wondering if anyone could give me some advice on what is possible with Mold Injection. I have read quite alot about Mold injection in the last few days to try and answer my own question but I figured there was substitute for the years of experience offered by a forum such as this so I thought I may as well ask you guys! I have a lot of experience building models from sprues of mold injected plastic , and I have some understanding of the various plastic material properties. I have a working knowledge of engineering and such things as sheer strength - but that's about it.

In short , Iam looking to create a Helix shape from plastic - for people who are wondering exactly what a helix looks like the easiest way to describe it is a coil spring. The kind of spring inside a ballpoint pen , or the kind of spring that goes over a damper rod in the front of an automobile. Another example is a spiral staircase.

My initial guess would be that this is very difficult. That said , I only require my helix to travel through 1 rotation of 360 degrees - so I think it could technically fit into a 2 part mold and be theoretically ejected as it doesn't double back on itself at all. I would ideally be looking to make the helix about 34 centimetres tall and 20 centimetres wide. I anticipate the thickness of the helix could be anything between 2 centimetres and 5 centimetres. I would be happy if the thickness of the helix would be a box section to create rigidity in the structure , Iam unsure if this would need to be hollow or solid. Iam guessing if its too heavy parts of the structure may end up sheering off.

The purpose of this plastic molding is entirely ornamental / decorative so as long its able to support its own weight - that is functional enough.

If the piece cant be made in a single 2 part molding , I was thinking I might be able to break the helix into 90 degree segments and assemble it - I think this is entirely possible as I have seen similar things done before. However I really want to explore the possibility of having the shape made as a single piece before going down that route.

I would really appreciate it if some one could spare the time to help me with this!

Thanks in Advance!

I apologise my first post is begging for help!

Michael Withers