SPE Thermoforming Quarterly®

Second Quarter 2020

The New Face of Plastics

It is not stretch to say that the world has changed since our last issue. Much ink has been spilled about COVID-19 and it will be some time before we can make sense of the short- and long-term disruptions to life and business. For those of us in the plastics industry, at least two comments can be made with certainty: one, plastics are an indispensable part of modern life; two, social and political pressures against certain types of plastics have abated. This commentary will focus on the former, but it would be mistake for the plastics industry to forget about or abandon what led to such an increase in global awareness of the impact of plastic waste on the environment…

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Second Quarter 2020

Improving Thermoformability of IPP Through Multilayer Co-Extrusion

While the flow forces governing primary melt-based polymer processing techniques, such as extrusion and injection molding, have been extensively studied, characterization of forces in secondary processes such as thermoforming is limited. In this work we utilize multilayer coextrusion to create an extruded film with 100s of alternating linear low density polyethylene (LLDPE) and isotactic polypropylene (iPP) layers; and by extension, 100s of interfaces. The combination of LLDPE, iPP, and these interfaces decreases the elastic storage modulus (Eā€™) and broadens the rubbery plateau observed via dynamic mechanical analysis (DMA). The broadening of the rubber plateau is correlated with an observed improvement in LLDPE/iPP multilayer thermoformability compared to the homopolymer LLDPE and iPP films…

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