Mahesh Gupta, president and CTO of Plastic Flow, has taught students, written software programs, solved differential equations and started a company.

But a conversation with him wouldn’t be complete without mention of one of his biggest achievements — conquering fear. As a little boy, he almost drowned, and as an adult, he forced himself back into the water, where halting, anxious movements away from the pool wall eventually became confident strokes, day by day, mile after mile.

Gupta talked about that evolution — as well as the one underway to simulate plastic flow in extrusion — during an interview with Karen Hanna, former senior staff writer for Plastics Machinery & Manufacturing.

What led you into the plastics industry?

Gupta: I did my bachelor’s and master’s in mechanical engineering, and I came to the United States [from India] to do my Ph.D. at Rutgers University in mechanical engineering. ... I wanted to work in Finite Element Method (FEM). I did not really know much about plastic. ... I selected a professor, [the] late Professor Tai Hun Kwon. He was my Ph.D. adviser at Rutgers. The reason I selected Professor Kwon, his research was an application of Finite Element Method for injection molding flow simulation. He used FEM for manufacturing, in particular injection [molding]. ... He was a good person. ... I developed the software for full three-dimensional simulation of polymeric flows using Finite Element Method, but I did not apply it to injection modeling, I applied [it to] polymer extrusion die design. ... For my post-doctorate research, I worked at [the] Cornell Injection Molding Program. I worked in injection molding, not in extrusion, and in particular, I developed software for prediction of fiber orientation in injection molded parts, and that software is still being marketed as part of Moldflow software.

What is FEM? Why is it important for plastics processing?

Gupta: Finite Element Method is a method for solving differential equations. When you have a differential equation, you can solve it for simple domains like rectangles or circular channels, but as a domain becomes more complex, like molding for injection molding or dies for [an] extrusion die, it becomes difficult to solve differential equations. What Finite Element Method does, it breaks the complex flow domain into smaller triangular or tetrahedral or rectangle or small elements, and it solves the differential equation on the small elements, and then combines everything into one whole. So, irrespective of how complex the geometry is, you can solve the differential equation very accurately. It’s a very powerful method, and that's what I was interested in for my research for Ph.D., and that's how it slowly got introduced into plastics.

Once you started at Rutgers, was it your plan to stay in the United States?

Gupta: When I came, I was quite sure I'm going to go back and teach at my school where I got my bachelor’s, Indian Institute of Technology [IIT] Kanpur.I told everybody, “I'm going to go back,” and many students [would say], “I don't want to go back.” Then, eventually, slowly, I decided the quality of research going on in the United States was much better than for my master's in India. So, the opportunities were much different; the quality of work was very different.

Once you graduated from Rutgers, what did you want to do?

Gupta: I wanted to be a professor. I enjoy independent research, I enjoy teaching. Right after my Ph.D., I couldn't get a faculty position, so I joined the Cornell Injection Molding Program for postdoctoral research. I worked with Professor K.K. Wang. He was a director of the Cornell Injection Molding Program, or CIMP — that's what we called it. I worked with him for that software for injection molding and also for simulation of viscoelastic flows. ... Professor Wang started Advanced CAE Technology to commercialize his injection molding finite element software — C-Mold. ... Advanced CAE Technology (C-Mold) was bought by Moldflow in 2000. Moldflow was bought by AutoDesk in 2008. I decided to follow Professor Wang's steps and started Plastic Flow to commercialize my polymer extrusion die design software — polyXtrue.

I decided I didn't want to compete with Dr. Wang, so I decided I would go back to my doctorate research and develop the equivalent of Moldflow, but for extrusion. When I got a faculty position at Michigan [Technological University] in 1994, I continued to work in injection molding for about five years till I got tenure. Then, I developed [the] equivalent of Moldflow.

What reaction did you receive from Dr. Wang regarding your decision to start Plastic Flow?

Gupta: He was very happy. He helped me quite a bit.

Do you think enough tooling makers are taking advantage of these kinds of tools?

Gupta: Well, the answer is, of course, no. Only a small fraction of die designers are actually using software. Most dies are still designed by trial and error. If you look back at the history of it, back in the 1980s, there was no good software available for extrusion dies, not even for injection molding. There was no choice but to design dies using the experience of the die designer, by trial and error, by fine-tuning ... till [the die is] good. ... Extrusion-die design software did not become as quickly adopted in industry as injection modeling software. But, at this point, the computing power is so much better. We are not [doing] two-dimensional simulation; we are into artificial intelligence (AI). The software is much faster, the computer much, much, much faster. It's very easy to do a full three-dimensional simulation.

You can simulate a full two-dimensional accurate simulation in about 10-15 minutes on a laptop. You don't need a supercomputer, which we used to do for my Ph.D. The full simulation not only predicts velocity and ratio in the die, but accurately predicts much, much more than that: What is the temperature distribution? What is the stress of the co-extrusion multilayer die? How will the layer structure develop? If you have metal cores going through the die, you can easily simulate that, and software not only predicts what's going to happen inside the die, but what's going to happen outside the die. ...

At this point, if you are not using Finite Element simulations to design or fine-tune the die, you're wasting your money. ... We guarantee to our customers the number of fine-tuning iterations they require for experiments will be reduced at least by 50 percent. ... When we make this claim to a new company, “It's a big claim, how can you do that?” The reason is because most of our customers tell us the reduction in fine-tuning iteration is not 50 percent; it's more like 70 to 80 percent. So, if your die design is costing you $20,000, we guarantee that if you do simulation ... it will not cost you $10,000. ... If you're not using the latest technology for virtual fine-tuning, optimizing, you are wasting money, a lot of time will be wasted, a lot of resources are being wasted.

What other new tools are gaining traction?

Gupta: With 3D printing, you can make a lot more complex flow channels, you can get more uniform cooling, which is not feasible if you use traditional machining. ... When you're doing 3D printing, you can manufacture any complex shape; it is layer by layer. You can make more complex dies, you can get a lot more uniform cooling, but the thing about 3D printing is that it's difficult to fine-tune a die. Once you make it, you can't add material. ... It's even more critical to make sure you fine-tune the die virtually or optimize the die using software.

How are you using AI?

Gupta: It's starting to come into manufacturing. AI has the power to write code very quickly; a lot of software developers are using software because of that. ... Some of the things which [would have been] impossible to develop ... I think that's possible with AI. ... It can write software 10 times faster than a software developer. ... That has power to revolutionize software development.

Can you tell me about your outlook for Plastic Flow?

Gupta: We have grown quite a bit. We have customers all around the world, in Europe, in North America; majority are in North America. We have customers in New Zealand, Australia, all across India. It's being used widely.

And you’re still balancing that with teaching?

Gupta: Actually, I've been teaching now for 32 years. I started teaching in 1994, and I decided to retire from teaching Aug. 1 this year. ... I'll be working full time for Plastic Flow.

I taught at Michigan Tech for 22 years, but for the last 10 years, I've been teaching in Atlanta. I moved from Michigan Tech 10 years back as a department chair for mechanical engineering at Kennesaw State University.

... The company is still Michigan, but I am in Atlanta now. I don't like that cold weather.

What did you enjoy about teaching?

Gupta: The good thing about being a professor is independence, academic freedom to work on anything you want, any kind of lesson. You decide what you want to work on. ... Second thing was always being among young people; no matter how old you are, you're always among 18- and 20-year-olds, so that makes you feel young. ... I enjoy giving lectures and communicating knowledge to students. I [could] have taught [a lesson] 50 times, but students are seeing it for the first time, and to be able to communicate the knowledge to them, I enjoy that.

What would you say to potential employers about the next generation of plastics professionals whom you've been training?

Gupta: I feel plastic is quite mature at this point, not what it used to be 30 years back. Not too many professors are working in plastics at this point, because professors work via funding. Where the money is, from the National Science Foundation, from other funding sources, it's slowly dried up. We have to find things which can be funded, so plastic research at this point is more into 3D printing. ...

My message to the professors and professionals in industry is even though the industry is quite mature compared to what it was 30 years ago, there are a lot of unresolved issues in plastics; there's still a lot of opportunity to make contributions, so continue to explore those unresolved issues. You can still make a contribution.

What are the biggest issues you see?

Gupta: The biggest challenge is recycling. More and more aggressive legislation is coming in many, many different countries, making it more and more difficult, particularly for single-use plastics, and for good reason, for environmental reasons. The big challenge [is] developing bioplastics, biodegradable plastics, and making them more affordable because they're very expensive.

From what I work on, co-extrusion is a good way of recycling plastics. Many of our customers use co-extrusion to recycle plastics. What they do, the majority of the profile is being made by recycled plastic, but there's a thin layer of virgin PVC, so it may be like 85-90 percent recycled plastic. ... A lot of our customers are designing dies like that, 85-95 percent of polymer being used is recycled PVC or other polymer, and just 5-10, 20 percent virgin PVC.

Do you think that we're going to see significant progress in sustainability?

Gupta: I hope so. That's important for the future of plastic, and it's also important from an environmental point of view. It is a challenge, of course. That research has been going for a long time, as long as I've been in the field of plastics. I know for 30 years people have been trying it. ... I hope that becomes feasible in my lifetime.

What do you like to do outside work?

Gupta: I enjoy exercise, swimming, yoga, hiking. I hope to travel more. [My wife and I] haven't traveled much. We plan to travel more in the next few years around the world. I also enjoy singing Indian/Hindi songs. About one and a half years back, I started taking formal training. Maybe I’ll take some lessons for classical singing. I have given performances the last couple years. It's like a meditation to me.

Tell me about swimming.

Gupta: The reason I love swimming was because I almost died drowning, when I was 5 years old. ...

When you make houses in India ... they dig a small tank for water storage, so they can have water needed for building a house. This was a neighboring house, and the house was built, but the pond was still there. Our neighbor invited us for the house-opening ceremony, and all the kids were playing around the pool. It was about 5 feet, 4 feet, too deep for me [as] a 5-year-old [with] only kids around. ...

Luckily, my sister and other people ran and pulled me out and revived me. After that drowning accident, I was so scared of water. If there was a small pool of water on the road because of rain, I would go to the other side. So, when I went to college, IIT Kanpur had a very good swimming pool. In the heat of Kanpur, that was heaven. I made sure I would get rid of my phobia for water. I decided, “If I don't do it now, I will always be scared.” So, in the first semester, I went to swim. It was so scary just to enter the pool. I was so scared, so much big water. Somehow, I took the stairs and went down and held the wall and stood there. That's all I could do, but I went every day. I stood there, and I would ask people to teach me. There was no professional swimming teacher. I would ask other students to teach me, and they [would] say, “OK, bend and take a push.” I refused to leave the wall. I held the wall and started paddling, and one day I let go. I didn't sink. After that, I enjoyed swimming so much. I quickly learned. I became one of the best swimmers in college. I used to swim one kilometer every day.

What places are on your travel to-do list?

Gupta: I heard the lands in New Zealand are amazing. Australia, some other places. We were in Europe last year, we have [been to] Switzerland and Austria. I visited Colombia a couple of years back. Machu Picchu. ... South America, Iceland. We don't like to go too many big cities; we like wilderness, natural beauty.

When you look back on your career, what do you think your biggest accomplishment was? What’s your legacy?

Gupta: My biggest accomplishment was, of course, my students. When I look back, the highest satisfaction is that my research will be used every day helping industry, helping somebody every day and making somebody's life better. About five or six years back, one of the companies who has been using our software sent me an email: “We have been having this problem for the last 11 years. Your software solved it for us.” I actually got a lot of satisfaction [from] things like those and, of course, my graduate students are helping industry every day, using what they learned. That's very rewarding. That's my biggest rewards: my research, my students able to help people in the plastic industry today.