In this podcast, Tom Rohlfs from Controlled Fluidics talks about acrylic. An extremely popular material and one of the first plastics commercially available for machining, acrylic offers a host of advantages. Take a look.
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 acrylic plastic manifolds. Welcome, Tom.
Tom Rohlfs: Hello, John. Thanks for having me. Sure.
John: Tom, what is acrylic plastic?
Tom: Yeah, sure. Acrylic plastic is probably one of the first plastics that were commercially available for machining. It’s a very clear window glass type material. It has many, many uses. It’s commonly known as Plexiglass or PMMA. It’s probably one of the most widely known and most popular materials available out there.
John: In order for a plastic to be machined, does it need to be a hard, rigid type of plastic?
Tom: We machine lots of different plastics. They run the gamut from very soft plastics like Teflon, up to harder plastics like acrylic. I was referring to the fact that many, many, the universe of plastics is very broad. Majority of them go into injection molding, but there’s a select group that are extruded or cast as a sheet or rod product to be machined. Acrylic was probably one of the first to be cast as a sheet for general purpose machining and application.
John: Okay. What are some of the characteristics of acrylic plastic that make it really useful for manifolds?
Tom: Yeah, sure. The big claim to fame for acrylic is that it’s very clear, looks very much like a window glass. Any type of imaging application requiring optics or super clear parts, it’s a great fit for. It’s also low, low cost. We’ve talked about other materials like polycarbonate and Ultem. They obviously have higher performance, but for some applications where cost is important, the application is relatively straightforward, i.e. pneumatics. Acrylic is a really nice choice for those types of things.
John: What are some uses of acrylic plastic manifolds at industries or types of uses for it?
Tom: Yeah, sure. Acrylic is interesting in that people see it all the time. It is used in point of purchase displays in like a local department store. It’s used in all sorts of different machine parts. At one point, acrylic found use in car lenses and even eyeglasses. It has a lot of advantages.
On the manifold front, it’s a very easily bondable material. We don’t have any trouble. We use a thermal process, which allows us to put a manifold together with heat, time, and temperature. Other people, it’s easily solvent bonded. You could go to your local hardware store and buy a can of solvent, put it between two pieces of acrylic, and actually get a bond. It’s not the way we produce manifolds, but it certainly is a material that’s easily bonded.
We talked about the lowest… It’s very low cost. It’s got excellent light transmission, up to 92%. It’s continuous service temperature is not as strong as most other plastics. Again, it’s a low cost plastic. It’s great for pneumatics, but in thermal applications where there’s some thermal demand on the system, anything above 150 degrees continuous surface temperatures, it’s, quite frankly, too high for it. What happens is it softens and starts to fail. There’s other plastics in the plastic universe that are a better choice for higher temperature applications.
John: You mentioned pneumatics. Can you explain that a little bit?
Tom: Yeah, so pneumatics… Sorry about that. Yeah. Pneumatics is when you’re trying to control flows of gasses, be it air, oxygen, any gas actually. We’re able to machine the parts so that valves can be mounted onto the manifold and you can control the flow of gas in, out, vacuum, things like that. It’s all about in a processing application, life sciences application, where you’re trying to direct a gas for a certain end goal. Acrylic’s a good choice for that type of manifold application.
John: In terms of advantages and disadvantages of using acrylic for plastic manifolds, and you mentioned that it’s clear, it’s low cost, it’s easily bonded, are there some disadvantages or reasons why you might not want to choose acrylic for your plastic manifold?
Tom: Yeah, absolutely. If you try to do any type of liquid application, generally, we try to steer our customers away from it. It does not have great chemical resistance. Again, low cost plastic, you get some low cost performance. Anything salt water, regular water, anything very mild is generally okay through acrylic manifold. But anything stronger than isopropyl alcohol, over long term, will cause the manifold to fail through stress cracking the chemical attacks, the plastic, in a way that starts to cause cleavages in the structure of the material.
It does not tolerate chemicals very well. Again, that’s why it always sees use and most oftentimes sees use in pneumatic situations where the gasses are not going to be aggressively attacking the material. It is relatively brittle. If you drop it on the floor, it can chip very easily. The upside to that brittleness is it’s very hard. From a handling perspective, it really maintains its clarity. It doesn’t scratch easily and it looks nice over the long haul. Yeah, that would be pretty much it.
John: All right. Well, that’s really great information, Tom. Thanks again for speaking with me today.
Tom: You’re welcome. Take care.
John: For more information, you can visit the website at controlledfluidics.com or call 603-673-4323.