plastic recommendation

[boldfish]

Does anyone have a recommendation for a type of plastic that can be injection molded, be FDA/NSF compliant and UL94 V-0 classified? Low cost is also preferred.

Part quantities are in the 150,000/year and the part size is roughly Ø100mm x 75mm.

Originally the part was spec'd as ABS/PC blend with fire retardant additives but I think this will not satisfy the FDA requirement.

Thanks in advance.

boldfish

 

[dgowans]

Low cost is also preferred.

No kidding?!?!?!? I'd have thought you wanted to pay an arm and a leg for material......

You could start at the UL website:

http://www.ul.com/iq

This would at least get you started on the V0 requirement - if you have other requirements you can start to filter for those as well.

 

[Demon3]

What requirements do you have? Your previous choice of ABS/PC implies you want very good impact resistance.

In your shoes I would go to

http://www.matweb.com

and enter the data for the ABS/PC you had intended to use then have the site search for a material with similar properties plus the flame retardance and see what comes up. The site is free so there's nothing to lose.

There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[patprimmer]

Brominated type flame retardants are typically used with PC/ABS. I expect that these exclude food contact.

Straight PC is easier to make FR, so I would contact major PC manufacturers.

Other than that, I need to do some research as to whether or not it can be done.

It may require a custom made compound if it is possible.

You only give 2 dimensions. That is exceptionally thin.

Is it a tube or a disc.

Availability of custom made compounds will depend on volume. What is the part weight in existing materials or what is the part volume.

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.

 

[Pud]

You need also to specify at what thickness you need the Vo rating...your thinnest part section.

Why does no-one recognise PVC anymore? Inherently FR, cheap(ish), lots of food (and USP)approved grades, etc...oh well, must be getting old..

If you intend to have a custom colour, then you are going to have to have it compounded by a UL approved source. Not many about - mainly the majors - expect to pay accordingly for the certification (i.e through the nose!)

Cheers


Harry

 

[patprimmer]

Pud

We make compounds with UL certification at Duromer in Sydney Australia, we are hardly a major only having 3 extruders, the best of which maxes out at 1 tonne per hour, but I agree in principle with your comment.

I think this might only be 2 or 3 tonnes per year which will severely limit any interest by anyone in developing a special compound.

I tend to deliberately forget about PVC as a lot of moulders won't touch it. It is problematic unless you are well drilled in moulding it and the necessary precautions when moulding it. It seems you are one of those who is experienced and competent in moulding PVC.

If you saw what UL charge us for qualification and annual fee, you would understand why we charge through the nose for small quantities.

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.

 

[Pud]

Pat,

Wish we had someone like you in UK! It's always a pain getting custom compounding in small lots done to UL. We make some electrical parts from UL approved FRABS, but we colour it so lose complete traceability but hey!, it does the job and the approvals board don't seem to mind (or understand!)

PVC is not that hard to mould - especially with modern stabiliser systems - problem is it is not liked by the "greens" for some reason (even though it's only 50% oil-derived. Oh well...

I have assumed a custom colour - perhaps the op could give some more details as it will be quite important.


Cheers

Harry

 

[boldfish]

I've done quite a bit of searching and inquiring but have had no luck. I would have thought someone would have encountered and requested these two requirements on the same part prior.

The component is used in a countertop water system and the design is such that this component is wetted and borders the electronics enclosure. So much for reducing part count and simplification, huh?

The part itself is fairly simple: roughly Ø100mm diameter and Ø75mm tall - think coffee mug shaped. There are severaly protruding features and surfaces but nothing that would prohibit a very easy injection mold. The thinnest section is about 2mm and the modeled part volume is about 90,000 mm^3.

Color is important but can be dealt with if need be. I had hoped for black but am flexible.

I don't have many other constraints. The assembled location provides a great deal of protection, so impact resistance is not a problem. Ideally, finished part characteristics should be similar to those of ABS or PC; but again the major concerns are with FDA/NSF compliant and UL94 V-0 rated. Compromise is expected.

And low cost is preferred.

 

[Pud]

Boldfish,

Black might be a winner - most UL stuff is available in black as well as natural. The real problem now will be getting FDA approvals.

You will need to look at materials which are inherently FR, as as Pat mentioned, FR systems are based on nasties (halogens such as Bromine) or "not so nice" (such as Antimony). The only problem with PVC is finding someone to mould it and a suitable injection moulding grade.

My immediate choice would be PVC (I think the US calls it vinyl?), with other options then into high performance stuff like PPS. You might also look at mPPO (e.g. Noryl) as there are FDA/NSP grades available. You will have to log on to the GE/Sabic site.

Anyone out there with other naturally FR stuff?

Cheers

Harry