Back to the future: Exploring extrusion at SPE’s ANTEC

At Walt Disney World in Orlando, you can go on a trip inside Spaceship Earth, the huge geosphere with mouse ears in the logo. You travel upward in an open train of little cars and see the history of communication unfold from cave drawings to computer.

Then you go backwards—the cars still facing the same direction—as you look up at the stars in the sky. That’s necessary for the ride down—if we faced forward, we’d fall out of our seats—but it has a symbolic meaning, as well.

I want to face the future with eyes, ears and mind wide open, and that’s one reason I went to the Society of Plastics Engineers’ Annual Technical Conference (SPE’s ANTEC) in Anaheim, CA, last week.

It’s over now but you still can “attend” by accessing the listing of 124 extrusion-related papers given at this conference, with primary authors, affiliations and descriptive titles, in last month’s column.

Tiny. Very tiny nano-materials have been around for a long time now, and can be too easily pushed aside by processors as too expensive and exotic, suitable only for special uses. It ain’t necessarily so. The huge surface area they offer can mean big changes in gas and moisture barriers to many substances, in electrical and chemical properties and, in coextruded layers, surface properties, as well. A nanometer, by the way, is one billionth of a meter. Very tiny.

Bioplastics. The buzz about bioactive polymers is still around but fading, as we learn that the environmental  benefits they appear to offer (their greenness, if you will) are wanted mainly by big retail brands to appeal to their consumer base, as long as they don’t cost too much or degrade product performance. This drags in some biobased polymers, too, which may or may not be bioactive. What I’m still looking for (but don’t expect to find at a public conference like this) is a fully biobased PET at no added cost compared with a petroleum-based material.

Lab equipment.  As the SPE is heavily academized, the exhibition area had a lot of lab equipment, including a tiny twin-screw compounder making a testable filament from a few grams of polymer. My favorite lab tool was shown, too: A torque rheometer, which can show thermal stability as well as melting behavior and dynamic viscosity.

Screw design and materials. Several papers dealt with this topic, including what causes screws to break in service. This is most important to buyers of new and rebuilt equipment, who should discuss design, dimensions and materials of construction in advance, if possible.

They also should consider specific resin properties (not just resin families like PE or PVC) and extruder operating conditions, and apply computer simulations where resin viscosities and machine size make it worthwhile. For the rest of us who use existing equipment, it is still good to measure what we have and to know what it can do, with and without add ons like static mixers and gear.

pumps. As readers of this column may know by now, to resolve a problem I’ll work with conditions first and modify materials, if necessary, before suggesting changes in existing equipment.

India. SPE has been quite active in India, and its population of 1.3 billion people (surprised me, too) represents a huge market for plastics.

There is now a Plastindia University under construction in the chemical city of Vapi, about 100 miles north of Mumbai, in cooperation with the plastics department at the University of Massachusetts Lowell, which was announced at a well-attended networking lunch on May 9. It’s far away and they can’t afford all the products we can here, but 1.3 billion is a lot of people and many of them can speak and work in English.

Personal note: I gave two talks at this year’s ANTEC: “Reading a material data sheet” (know and understand the numbers) and “The ten (11) key principles of extrusion,” which I’ve given as a webinar five times already but still commanded a good audience of newbies and re-newbies. You can contact me for copies of the slides for either or both presentations.

Books. You can take it with you, as so much technology is available in book form, and many of the authors are still around for further discussion and consultation. Here is a list of extrusion-related books that were on display at Hanser’s booth at ANTEC that have been published in the last three years (all of which are in English):

Diagnostics of Extrusion Processes , Rao, 2014

Die Design for Tubes and Pipes , Kainth, 2017

Extrusion Dies for Plastics & Rubber , Hopmann & Michaeli, 4th Ed., 2016

Plastics Handbook , Osswald, et al., 2017

Plastics Packaging , Selke & Culter, 3rd Ed., 2016

Polymer Engineering Data for Resins and Machines, Rao, 2017

Polymer Extrusion , Rauwendaal, 5th Ed., 2014

Polymer Processing , Agassant et al., 2nd Ed., 2017

PVC Additives , Schiller, 2014

Understanding Plastic Recycling , Rudolph et al., 2017

Understanding Polymer Processing , Osswald 2nd Ed., 2017.

Allan Griff is a veteran extrusion engineer, starting out in tech service for a major resin supplier, and working on his own now for many years, as a consultant, expert witness in law cases, and especially as an educator via webinars and seminars, both public and in-house. He wrote the first practical extrusion book back in the 1960s as well as the Plastics Extrusion Operating Manual , updated almost every year, and available in Spanish and French as well as English.


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