Glass

Soda-lime glass

The most commonly produced type of glass we encounter mainly in the form of window glass, glass bottles and food jars. The composition of approximately 71-75% sand, 12-16% sodium oxide and 10-15% lime creates a surface that is particularly smooth and pore-free, easy to clean and translucent. The only disadvantage of this type of glass is its temperature behaviour: if hot liquids are poured in too quickly, the glass expands and can burst.

Borosilicate glass

For particularly resilient and durable glass, the proportion of lime and sodium oxide is reduced to a total of 4-8 % and 13 % boron trioxide and 2-7 % aluminium oxide are added instead. The addition of these substances makes the glass particularly resistant to chemical effects and high temperature fluctuations. That is why this glass is often found in industry, laboratories, the pharmaceutical industry or as lamp glass. But everyday objects are also made of this durable material: e.g. baking and casserole dishes, drinking straws for hot drinks or glass cups.

Crystal glass

The name is a little misleading for this type of glass. Because, from a purely physical point of view, crystal glass is not crystalline. It was named after the similarity to crystals such as quartz, which came about through the refractions and colour effects due to the added metal oxides or ions (13 - 15 %). It is mainly used for drinking glasses, vases, bowls or decorative elements.

Why is glass so sustainable?

Glass is so sustainable because most types of glass are recyclable. And not only that: It can go through the recycling cycle any number of times without losing raw mass. Above all, this conserves the resource sand, which is becoming increasingly valuable due to its intensive use in construction. Once produced, glass bottles can be washed out as well as melted down and processed into new glass products. By adding waste glass cullet, the melting point of the raw materials in glass production can also be lowered - this protects the environment thanks to the reduced energy consumption.

How is glass disposed of in an environmentally friendly way?

To support perfect recycling, it is important to separate the different types of glass correctly. However, not every glass can be disposed of in the waste glass container / bottle bank. Borosilicate glass, for example, cannot be recycled due to its high degree of melting, as such high temperatures are not reached when melting waste glass. Borosilicate glass, however, is shatterproof and dishwasher-safe, so that glass drinking straws have a significantly longer lifespan than plastic drinking straws. This means that glass, although not always recyclable, is significantly more sustainable than single-use plastic solutions. Our conclusion: The glass of sustainability is half full and not half empty.