Glass is made of silica sand, sodium carbonate, calcium carbonate, and other minerals. These materials are first mixed together in a rotary tumbler with water. After this tumbling, the glass mixture is poured into a furnace and heated to 1400 degrees Celcius, although the temperature will eventually rise to 1540 degrees Celsius. This process takes around four hours.
Next, a forehearth removes the glass from the furnace, blowing hot and cool air to reduce the temperature of the glass. Then the glass enters a forming machine, which molds it. After molding, the glass cools more is then sent through a kiln, which reheats the glass to 600 degrees Celsius and then slowly cools it to strengthen the glass.
What Happens Next?
After the bottles are shipped, they are sold in stores and restaurants. Most bottles are used only once before they are thrown away or recycled. Recycling glass is generally easier and more effective than recycling plastic or paper because glass is 100% recyclable, meaning that the entire bottle can be reused. When glass is recycled, it must first be picked up and shipped to recycling centers. Then, the glass is cleaned and sorted at the recycling center. The recycling center will then go through the process of forming bottles after breaking down the glass. By 2013, glass manufacturers plan to use 50% recycled material in the production of new glass bottles. This should save enough energy to power 45,000 homes for a year, as well as save 181,500 tons of waste from being dumped into landfills.
If the glass does end up in a landfill, it can last for several hundreds of thousands of years. Its lifespan is essentially infinite. Therefore, it is important to continue to recycle glass bottles and use reusable bottles when possible.
Above: A glass recycling center in the UK shows a vast amount of waste.