Large part mfg problem

[gallen29]

Hi All !
I have a part that I am looking to produce a few thousand of. Sounds simple enough right ? Well, the part is almost 41 inches in diameter and has a volume of 465 cu in (almost 20 lbs). The has a little complexity and is a straight pull. I tried getting injection mold quotes, but was turned down everywhere I went (part is too heavy).
Any suggestions for maufacturing?

Thanks

 

[plastx]

Have you considered thermoforming? The part thickness may be an issue but that depends on the material you have selected.

Mike

 

[patprimmer]

Rotational moulding might also work.

I do know a moulder who could injection mould it, but tooling costs would be enormous.

Any moulder who does automotive bumpers should have the capacity if not the will to do the project.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[gallen29]

Thanks for the replies (and fast too). Thermo forming and/or Rotomolding will not work. The geometry does not lend itself to these process's. I have tried a couple of automotive suppliers that would be capable, unfortunetly, they have all been unwilling to help. I may need upwards of 10k parts in the first year. Automotive OEM's will not sign up for these quantities as it would 'interfear' with the automotive parts schedules. I thought of RIM molding, but could only find one supplier (and they said no as well). As you can see, I have been working at this for a while, its starting to get frustrating !

 

[patprimmer]

There is a company called Reln near Sydney Australia.

http://www.reln.com.au

They specialise in very large mouldings.

Australians are used to small runs, in fact we might be considered the worlds small run specialist nation with a high degree of physical seperation from other markets and a home market of 20,000,000 people.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[dgowans]

I used to work for a company that is now a part of Clarion Technologies (

http://www.clariontechnologies.com)

which had a 1500 ton injection molding machine. At the time the machine was molding fan shrouds for the military Hummers. I don't recall what the shot capacity of this machine is, but you could check them out if the location is acceptable.

 

[ehw]

for injection molding - try to contact somebody how ist making injection molding of garden chairs, tables - they are normaly interested in other projects

 

[deper]

Would Fiberglass work?

 

[PlasticsProcessor]

Its tough to say without see a drawing of CAD model of the part. Many times with parts of that size and annual volume, thermoforming is possible, with the right tooling. Breakaway molds can be used which allow for areas that might cause problems to breakaway from the mold after forming. Injection Molding, especially for a part that size can get to be quite pricey for the tooling. Try

http://www.arrowheadinc.com

, they are a plastic and fiberglass processor in Indiana.

 

[injectionmolder]

Pre production plastics in Corona CA (no affiliation to this place)
They have presses with up to 25 pound shot, structural foam, gas assist, and injection molding, just what you might need for that size of part.

Regards

 

[hoodman]

Bemis Mfg in Sheboygan WI could help. They have the largest co-injection press in the world. I currently have a part being made their that is 9 feet long, 3 feet wide and 2 feet deep. Weight is around 60lbs. However this is thin walled, 4.5mm.

http://www.bemismfg.com/

Don't let the tolet set thing get you.

Regards

 

[ozchevy]

You say geometry is a problem for Rotomoulding,
It may not be, the company I work for, mould parts that are in two or three sections, each part moulded individually and assembled inside each other then moulded over again, a typical example of this is our revolutionary made Hospital Vacuum Pump, which we designed and export worldwide.

Saying that though, you may be right - I'm sure you have researched all avenues, but as a previous poster has suggested (differcult to say without a drawing)