Glass is a wonderful substance. It can be recycled over and over again. The good thing about glass recycling is that the glass retains its quality. Cullet, better known as domestic glass, is the most common glass. Imagine how many bottles of soda, juice and glass jars are used daily. If we were to simply throw them away, the environment would suffer greatly. It is therefore important that the culture of recycling be kept alive.

Cullet is easy to recycle. It has an unlimited life. It can be melted and recycled endlessly to make quality new glass products. The glass manufacturers mix cullet—a granular material made by crushing bottles and jars — with limestone, sand, and other raw materials, melts the glass to manufacture new glass containers.

According to Glass Packing Institute, 10 million metric tons of glass are disposed of every year in the US, and yet only 33% of waste glass gets recycled, which pales when compared with the 90% recycling rate in Switzerland, Germany, and other European countries.

Environmental Impact of Glass Recycling

By simply recycling glass, we can:

  • reduce non-renewable fossil fuel usage
  • reduce the emissions of process CO2 from the carbonate raw materials such as limestone.

Glass recycling

Learn More: All About Glass Recycling Machine

How is glass recycled?

Once the glass is collected, it goes through reprocessing, which includes the following steps:

Step 1: The glass is crushed, and the contaminants are removed. If required, mechanized color sorting is also done at this stage.
Step 2: The crushed glass is then mixed with the raw materials to color and/or enhance properties as necessary.
Step 3: The glass mixture is then melted in a furnace.
Step 4: The melted glass is then molded or blown into new glass bottles or jars.


Glass Recycling Loop

Credit: Glass Container Recycling Loop

Advantages of Glass Recycling

  • Recycling of Glass Saves Energy
    Recycled glass melts at a lower temperature than its raw material components. The amount of energy required to make glass from scratch is 40% more than that needed to recycle it. If recycling is done on a large scale, maximum profit is achieved. Research has shown that recycling of a glass bottle can produce enough energy to light up a normal bulb for 4 hours.
  • Recycling of Glass Reduces Industrial Pollution
    The levels of pollutants that are released daily into the air around the world are very alarming. Recycled glass reduces the emissions of air and water pollution by around 20% and 40% respectfully. Reducing industrial pollution benefits not only the environment but also the entire ecosystem.
  • Glass Recycling Pays
    Some countries have capitalized on the financial gains that can be had from recycling glass. In America for instance, some states have recycling programs that offer cash incentives for most recycled glass products.
  • Recycling of Glass Conserves Natural Resources
    Recycling glass saves on the need to obtain more raw materials to make new glass. Industrialized nations with strong economies are aware that their economies grow more when monies do not have to be earmarked for tree planting or purchasing fossil fuels. By recycling glass, they save the natural resources that they already have.
  • Recycling of Glass Conserves the Landscape
    The aesthetic value of the environment is greatly improved through glass recycling. Many people tend to litter parks and parking lots with glass and another packaging. Due to the inorganic nature of glass, it will never decay. Recycling glass is very simple, and you can start the process by dropping the glass you have into recycling bins.
  • Recycling of Glass Is Good for the Environment
    A glass bottle sent to a landfill can take up to a million years to break down. On the other hand, a glass bottle from your kitchen takes as little as 30 days to leave your recycling bin and appear on a store shelf as a new glass product.
  • Recycling of Glass Is Sustainable
    Since glass containers are 100% recyclable, they can be recycled endlessly with no loss of quality or purity.


Disadvantages of Glass Recycling

  • Not All Glass Can Be Recycled
    Even though glass items can be recycled, there are a few exceptions. For example, glass from light bulbs and window panes cannot be recycled because they contain ceramics and other impurities that would contaminate the entire recycling process.
  • Glass Recycling Creates Unemployment
    It has been argued that glass bottle recycling has a significant impact on employment within the glass manufacturing industry. Millions of individuals who would have otherwise been gainfully employed providing manpower to create new glass items lose out on this opportunity as fewer people are needed to work in glass recycling plants.
  • High Costs Associated With Glass Recycling
    For glass to be properly recycled, it has to be separated by color. This process is quite labor intensive and rather complicated. Recycling in most countries is also done overseas due to a lack of proper facilities locally, making it very costly.
  • Glass Is Becoming the Contaminant 
    Glass is increasingly becoming the contaminant in a single recycling stream. The broken glass can contaminate other recyclables like paper and cardboard, lowering their value.
  • Broken Glass Is Difficult to Sort 
    Broken glass is difficult to sort, and if it’s broken down too finely, it may become too difficult to reprocess. When it is too difficult or expensive to separate out the glass, the recyclers send the entire stream to the landfill. According to Recycle Across America, more than 28 billion glass bottles and jars end up in landfills every year.


Glass Recycling Facts: Key Takeaways

  • Glass is 100% recyclable. This means it can be recycled again and again without losing its purity and quality.
  • Glass is manufactured using readily available domestic materials, such as soda ash, sand, limestone, and cullet (furnace-ready recycled glass).
  • Glass recycling uses sand in greater volumes than cullet. These materials are mixed, heated to a temperature of 2600 to 2800 degrees Fahrenheit and then molded into the desired shape.
  • Recycled glass can be substituted for up to 95% of raw materials.
  • Recycled glass saves energy, decreases the consumption of raw materials, and reduces emissions. It also extends the life of plant equipment, such as furnaces.
  • Glass manufacturers always require high-quality recycled container glass to meet the market demands for new glass containers.
  • The more the use of recycled glass, the lesser will be the energy used in the furnace, making glass recycling a profitable process in the long run. It lowers the manufacturing costs and benefits the environment as well.