Tempered vs. Partially Tempered
July 2022
Do you know how your glassware is made?
Not knowing could cost you big: downtime for your kitchen, costly cleanup, even liability issues, all stemming from dangerous breakage.
That’s why, as you’re outfitting your bar or restaurant, understanding glassmaking processes can help you assess your options and make a confident choice. Libbey glassware is manufactured for not only beauty and clarity, but with performance, safety and your bottom line in mind.
The majority of Libbey glassware is annealed, a process that slowly cools the glass after it is formed, removing all tension and easing the stress that was added to the glass during its formation. When annealed glass breaks, it comes apart in a few large pieces instead of shattering violently, making cleanup easier and significantly reducing downtime and liability.
Learn more about the annealing process by watching the video on our Instagram!
By contrast, tempered glass – a popular option used by some Libbey competitors – is heated up beyond the strain point and cooled down rapidly, effectively increasing the impact strength of the glass by 2 to 4 times. But because the process adds a significant amount of tension to the glass, when it does break, it does so violently – throwing tiny shards across your floor, into ice bins, and even into guests’ hands.
One alternative that combines the safety of annealed glass with the strength of fully tempered is rim tempering, which isolates the strength of the glass to the rim and helps prevent any large failures when the glass does ultimately chip. Because the rim is the part of the glass most susceptible to damage, rim tempering – also known as partial tempering – helps the glass last longer.
DuraTuff, a special thermal after-process for pressed tumblers and stemware, increases a glass’ resistance to mechanical shock. Heat Treated blown tumblers and stemware go through a special heating and rapid cooling process to reduce mechanical shock; this process is recommended for fast service cycle operations.
These two processes are just a few of the performance-enhancing details that set Libbey glassware apart and have kept us a favorite of foodservice professionals for over 200 years. Our legacy of glassmaking expertise and innovation means that Libbey is always developing new ways to support your creative vision.
Connect with your Libbey sales representative to learn more and explore our full collection.
