In this podcast, Tom Rohlfs talks about the advantages of ultem. He talks about its thermal strength and resistance as well as its chemical resistance. Then, he outlines some popular applications.
John Maher: Hi, I'm John Maher. I'm here today with Tom Rohlfs, President and Principal Engineer at Controlled Fluidics, a plastics machining company specializing in precision manifolds. Our topic today is Ultem plastic manifolds.
Tom Rohlfs: Hello, John. Thanks for having me.
What Is Ultem Plastic?
John: Sure. Tom, what is Ultem plastic?
Tom: Sure. So Ultem was developed by GE, I believe, possibly the '50s or '60s, as an insulator material that went into their transformers. So it's claim to fame is historically, it's great resistivity, it's great insulating capabilities for electrical requirements.
What's interesting about Ultem is that it's also shown up in life sciences plastics because of its unique characteristics. It kind of stands alone in the amorphous plastics as having advantages over others.
Why Is Ultem Good for Plastic Manifolds?
John: So what are some of the characteristics of Ultem plastic that make it particularly good for manifolds?
Tom: Right. So we see Ultem showing up almost primarily in liquid applications where you're flowing reagents, some sort of processing liquid through the manifold. It doesn't show up in pneumatics because it's, quite frankly, just too costly. It's quite a bit more expensive than acrylic. So that type of performance isn't really seen or necessary on the pneumatic side.
But on the liquid side, chemical resistance is critical. It has very good tensile strength. It's one of the highest tensile strengths, more so than polycarbonate acrylic, so it can tolerate a little bit more loading without any detrimental effects.
It is an amber color. The thicker it becomes the darker that amber is. So if you can imagine something that's about half inch thick, it's got quite a yellowish, sort of tannish look to it. It's clear, it is a clear plastic, again in the amorphous family, but it isn't necessarily that window grained clarity like a piece of acrylic might have.
It's very good on flammability. It's V-0 class material. So if there's any flammability concerns, sometimes this occurs in the devices they're looking for V-0 class flammability rating, Ultem meets that.
So the big things here is a great chemical resistance, great tensile strength, good flammability, and also good thermal resistance. Again, feeding back to that insulating capability, it's got quite a bit higher continuous surface temperature than acrylic would be, to 330 degrees. Acrylic would be only 150 degrees. So for applications that need stronger thermal resistance on a continuous basis, Ultem's a good fit.
The big downside to Ultem is, one, the lack of clarity, meaning it has a color, amber, it's clear, but it does have quite a bit of tint. And two, the cost is quite expensive. It's certainly for applications that need it, generally speaking, the application can afford it, but it doesn't produce a low cost result.
Uses of Ultem Manifolds
John: Okay. What are some uses of Ultem plastic manifolds that you've seen?
Tom: There's probably two locations. We've seen it used quite considerably in the aerospace applications. It has great properties. Those applications oftentimes require temperature extremes, that the manifold tolerate large temperature extremes below zero Fahrenheit, say to above 150 degrees Fahrenheit, continuously back and forth on a cycling basis without any failure. Ultem really meets that well. So the aerospace industry tends to like that.
Secondly, gene sequencing, a big application there. Many of the fluids in gene sequencing are quite aggressive and Ultem meets their chemical resistance requirements. So those are probably the two big uses. But again, anybody really looking for better thermal strength, thermal resistance, and chemical resistance, Ultem is a good choice.
John: Okay. You mentioned that the sort of the cons, if you will, of using Ultem for plastic manifolds would be the lack of clarity and the cost being a little bit more expensive. So with that lack of clarity that you wouldn't be able to... You said it is somewhat clear, but you wouldn't be able to sort of shine a light through it in the way that you can with acrylic plastics and be able to really get a good look at what the material is that's inside it, that's right, right?
Tom: You can definitely see through them, they are quite clear, but because of the heavier tint, we don't see many imaging applications. The tint distorts the picture of whatever material or whatever they're investigating inside. So that certainly, I mean, you can see fluid movement, you can see bubbles, you can see things like that, but because of the tint, there's some distortion there of what they're trying to image. So yeah, you have the clarity, but you don't really have good sort of bio detection applications. That's just not a fit for Ultem, generally.
Advantages of Ultem Plastic
John: And in terms of the pros for Ultem plastic, you said that it has good electrical resistance, good chemical resistance, good thermal resistance, and low flammability. Is there anything else with Ultem plastic that you'd want to mention?
Tom: That would probably be the bulk of it. It is relatively easy to machine, similar to acrylic polycarbonate. It also readily bonds. So those are benefits to it. It's not a material that's particularly difficult to work with. Again, we use a thermal process to bond the material together, and it's quite stable and quite straightforward approach for us on the bonding side. So there's no concern with that.
Contact Controlled Fluidics
John: All right. Well, that's really great information. Thanks again for speaking with me today, Tom.
Tom: You're welcome. Take care.
John: And for more information, you can visit the website at controlledfluidics.com or call (603) 673-4323.