Guidance required: PMMA injection molding

Hi all,

New member here, looking for some general guidance with regards to PMMA injection molding.

I'm in the final stages of product development for an LED lighting system, and require a PMMA optic. I have modelled this up in CAD (I can send a copy if required), and the overall part dimensions are 220 mm x 180 mm x 6 mm. There is a 2mm wall thickness consistent across the part. All faces have been drafted, and all corners radiused. There are no undercuts, and as far as I can tell (by following design manuals) the part should be producible using a simple two part cavity / core mold. I have sent the cad model to an injection molding company, and have received a tooling quote back for £25,000.

I have no experience in injection molding, however I have been a CNC programmer and draftsman for most of my life, and therefore have some knowledge in manufacturing. I understand that injection molding (and die production) is an extremely complicated process, however I cannot understand how the die could be this expensive.

Given that this forum is full of experts, could any of you please let me know if this sounds like an acceptable price, or offer any tips on how to reduce the mold cost further?

I have uploaded some images of the part as I cannot attach CAD models. Hopefully they can give you an idea of what I am trying to produce.

Thank you in advance for any help that you can provide. It will be greatly appreciated.

Carl

Hello Carl,

Welcome to the forum.

Lighting tools can be expensive since you need mirror finishes and so on (if not your lens will not be clear). Additionally, there are some features not easy to be polished for such a finish. They also may be using a stripper plate instead of ejector pins to prevent any ejector marks (not sure). So tools can get expensive.

I suggest that you get this quoted from at least 3 to 4 mold makers including China. The lighting industry is pretty mature and you will find several people willing to quote. Just be careful and go via references (only).

Suhas

Depends if you are buying the mold frame too.

If you requested a stand alone mold that can run anywhere, it will be more expensive. If the vendor has a MUD (multi unit die) frame standard it will be much cheaper. But then you are kind of stuck using that custom molder that has the frame.

I second China. There are a lot of automotive places that specialize in light housings, light pipes, stuff like that. It's all pretty much in the Shezhen/Dong Guan area. But there are thousands of mold shops there. I have connector contacts but nothing for lenses. But everybody knows everybody so I could ask if you need me to.