More than 12 million tons of glass are produced annually in the United States, but only 25% of glass is recycled and non-soda lime silicate glass compositions used in smartphones and other electronic devices cannot be recycled at all. Penn State recently received funding for the project, “Enabling Improved Glass Recycling Technology and Modeling Tools,” to help promote higher recycling rates in Pennsylvania.
On April 8, Gov. Tom Wolf announced a $2.3 million investment in 36 student research projects aimed at advancing innovation in several sectors of manufacturing. The 36 projects are part of Manufacturing PA Initiative’s fellowship program. The program embeds the commonwealth’s best and brightest graduate and undergraduate students with local manufacturers. Once paired, the students embark on research projects to develop new technologies and advance innovation statewide.
John Mauro, professor of materials science and engineering at Penn State, will serve as the project’s principal investigator. Penn State will partner with Remark Glass, a woman-owned startup company focused on innovative and creative glass recycling, to address several technical challenges facing glass recycling.
“I am excited to partner with Remark Glass to help find solutions to expand glass recycling opportunities and reduce the amount of glass waste going into landfills,” said Mauro. “This funding will also provide a unique opportunity for one of our graduate students.”
Based in south Philadelphia, Remark Glass was established in 2016 and is Philadelphia’s first zero-waste certified company.
“As Philadelphia’s first zero-waste certified business, we have earned gold status by diverting at least 90% of the material from our business from becoming landfill waste by creating recycled glass products through various glass making techniques,” said Rebecca Davies, co-founder of Remark Glass. “We are looking forward to partnering with Penn State to enhance possibilities for glass recycling.”
Glass is, in principle, an infinitely recyclable material and lends itself to a variety of recycling processes. Post-consumer waste glass is typically recycled as cullet — glass that has been crushed or imploded and ready to be remelted. For traditional glass manufacturing, the cullet must be sorted by color, since mixed-color glass cullet cannot be easily manufactured into new products with the desired optical properties. Another challenge is to establish recycling streams for specialty, non-soda lime silicate, glasses such as Pyrex or Gorilla Glass. To avoid sending these specialty glasses to the landfill, novel recycling techniques must be implemented, often in non-traditional applications.
This project will fund one graduate student to work closely with Mauro and Remark Glass to thoroughly characterize different colors and compositions of glass cullet and develop predictive models to allow for mixing of cullet and use of alternative compositions. Characterization will include viscosity curves for press molding, optical color coordinates to predict and fine-tune glass color, thermal expansion coefficient for thermal shock resistance, and liquidus temperature for quality control. Predictive models will be developed and delivered to Remark Glass to enable the used of mixed-color and mixed-composition cullet and tailor-design glass products and processes for use with recycled glass.
The deliverables from this project will include the first-ever modeling tools specifically to aid in glass recycling, according to Mauro. This will help establish Pennsylvania as a leader in glass recycling technology.