Medical Grade Resins - Worth the Money? 2

[bpcash]

My company manufactures surgical instruments for use in a broad array of specialties. We have some plastic disposable components, and recently one of the quality/regulatory guys decided we should be switching to medical-grade on all our resins (right now, mostly PC, Ultem 2100, and Vectra A130). I spoke to some of our molders and a Ticona engineer, and basically got the impression that these grades are not worth the extra money, especially since we still have to do cytotoxicity testing on a (semi) finished product. Also, I'm aware of at least one large medical device manufacturer that completely eschews the Vectra MT1310 in favor of the A130.

Does anyone have experience with using (or deciding not to use) these grades?

 

[MacGyverS2000]

If what you're using stands up to the autoclave, I see no reason not to use it (assuming there's no deleterious effects on the person it's being used on).

Dan - Owner

http://www.Hi-TecDesigns.com

 

[Demon3]

Medical grade resins are often the exact same resins but with certain guarantees added. For instance, the manufacturer promises not to change anything at all in the formulation and if they ever discontinue the material, they promise to stock e.g. 3 years supply to help you transition to something new.

Basically, unless your material has to be medical grade, you are throwing away huge amounts of money for nothing by switching. You could easily pay double for the exact same material you were already buying but labeled as medical grade.

Chris DeArmitt PhD FRSC CChem

http://www.phantomplastics.com

Consultant to the plastics industry

 

[loughnane]

An anecdote...

I worked with a guy who was doing medical device development for a big medical OEM and had designed with Cycoloy C6600 (pretty generic grade of PC/ABS). Everything was fine and then all of a sudden they started to see a spike in failures in the form of cracking during usage.

They did all sorts of testing, starting at the beginning: FEA of the CAD, quality of raw materials, injection molding process, etc., and what they eventually determined was that the only thing that had any correlation to the failures was at the usage end of the spectrum: the hospital had changed cleaning procedures to include a new brand of cleaner that contained quatenary ammonium compounds.

The chemists at the OEM worked with the material supplier to get around this, and out pops a new grade of PC/ABS" Cycoloy 2244ME which, and i quote, "demonstrates improved chemical resistance to general hospital cleaners which can be considered for healthcare enclosure applications."

They shot new parts in the 2244 ME and the problem went away. So in that case there was a legitimate improvement to be made by using a medical grade resin (although the cost can be 2-3x)

The other thing that you might want to consider is sustainability. Big names like Kaiser Permanente (who just came out with a sustainability scorecard... google it.) is pushing RoHS resins, recyled contents, and keeping DEHP + PVC out of products. Pushing it so hard in fact, that if price + performance are about the same they say they will go with the "greener version".

Chris Loughnane - Product Design

http://www.pdnotebook.com

http://www.twitter.com/DesignNotebook