Fire and sand

Glass production

"The path to achievement starts on the day you take total responsibility for your actions." (Dante Alighieri)

Everything that we do at Vetropack is based on the principles of sustainability and long-term success: we are circumspect in our business, environmentally aware in our actions and mindful of our social responsibilities. For example, it was in the mid-1970s that we first set about our pioneering work to develop a system for recycling glass. We work constantly on our process engineering because each innovation improves the energy balance of our production. Even though we handle 4.5 billion tonnes of glass a year, every gram counts.

Here is the recipe for top-quality, sustainably-produced glass.

Glass is made from natural elements. The main component is quartz sand. Soda lowers the melting point of the sand. Lime makes the glass hard, shiny and durable. At Vetropack, however, used glass plays a key role. Making glass from used glass uses less energy and fewer natural resources than making it from the primary raw materials of sand, lime and soda. We also use special processes that enable us to make glass lighter while retaining the same quality.

Up to 90% used glass, and
  • sand
  • lime
  • sodium carbonate
  • potash
  • feldspar

Melting

The furnace heats the mixture to 1580° Celsius. The used glass and the primary raw materials melt. The heat that is required is generated by natural gas. 

Shaping

The molten glass is in a constant state of flux. Glowing gobs of glass are cut off, guided into a channel and fed into the parison mould. In the blow mould, compressed air gives the glass container its final shape.

Cooling

In the annealing furnace, the glass jars and bottles, still glowing red-hot, are gradually cooled down to release any tension in the material. The surface is then treated to protect it from scratches.

Testing

At the cold end of production, we test our glass containers for faults visually, mechanically and electronically. Any products that do not meet our high quality standards are melted down again.

Packing

In a fully automated process, the glass containers are lined up on pallets and wrapped in film. Then, packed like this, they go to the finished goods warehouse or directly to outgoing goods.

We take responsibility for the environment: Lightweight glass from Vetropack

A 0.75 litre wine bottle made of lightweight glass weighs only 350 grammes instead of 400. A small beer bottle in lightweight glass comes out at 160 grammes, 30 grammes less than the traditional version. It is not only the end users who appreciate that. The reduction in weight is also good for the environment: fewer raw materials, reduced consumption of energy and materials, lower transport costs, lower CO2 emissions. The bottlers, retailers, consumers and the environment all benefit from this new lightness.

We take responsibility for quality: Knowledge, experience and expertise at Vetropack

New production technologies, friendly customer care, design, development and quality testing are in the hands of our over 3,000 employees. These men and women are masters of their crafts, whether they are glassmakers, glass designers, process engineers, glassmaking machinery technicians, glassmaking supervisors or machine operators. They adjust, control and check the certified (ISO, FSSC) production stages and so ensure consistently high quality in production.

We use tried and tested methods to produce lightweight glass that is just as stable, high-quality and strong as its heavier counterparts. Instead of the traditional blow-and-blow process, we use the narrow neck press and blow process for our lightweight glass: to ensure that the walls of a glass container are both as uniform as possible, and at the same time thinner, a plunger, known as a leveller, is pressed into the liquid glass while it is still in the parison mould. 

Before production comes the design phase which is critical for the high strength of the lightweight glass. The glass designers break down the glass container into smaller units on their computer screens. This allows the structural behaviour to be more easily analysed than for the complete article. Using this finite element method, they calculate the point at which the container is subject to particular stresses and then modify the shapes to reduce the stress.

We take responsibility for our customers: Flexible multi-gob production

Wishes are good because they change the world. Our customers are increasingly expressing a wish for short production times and greater flexibility in the number of items that are made in series production. Thanks to our careful production planning, cross-site collaboration and flexibility, we can meet almost every customer request. At the Vetropack plant in Croatia – and from the start of 2017 also at the Austrian glassworks in Pöchlarn – we offer the option of multi-gob production specifically for small-series production. This means that we can make two, and in some cases even more, glass containers that differ in their shape and weight on one glass-blowing machine. A special sorting machine then automatically forwards the different glass products for product-specific quality testing and packing.