Glass production

Glass production

Production process

More goes into the production of container glass than simple manufacturing. In line with our corporate philosophy, our business dealings are characterised by occupational safety and environmental concerns.

Our primary aim however is to ensure our products remain top quality - for extremely satisfied customers every time.

Raw material feed

The raw materials, incl. the used glass, are weighed and mixed to the right proportions and transported by conveyor belt to the furnace. 

Precise adjustments and corrections to the mix are necessary owing to the ratio of used glass with its ever-fluctuating composition. 

Batch preparation

Forming glass

Glass container manufacture is a high-temperature process - raw materials are melted into glass at 1590°C which flows via a series of channels to the glass forming machine.

The glass forming machine portions off single drops from the constant flow of glass. These are then fed into the various processing stations.

Melting and forming

Quality assurance & packaging

Every single one of the 10 million glass containers produced daily is tested for compliance with our prescribed quality characteristics by a series of linked devices.

 

Graphic quality control

 

Circles

Cycles

Manufacturing with a minimum of emissions is the most effective guarantee of environmental protection.

Closed production cycles bring environmental relief in a variety of ways:

  • by saving and recovering energy
  • by reducing emissions
  • by reducing water consumption
  • by recycling all materials that can be reused.

Water

Water circuit

All the water needed for processing is held in a closed cycle, only a minimal amount – 1.7% - drawn off as waste water or lost through evaporation needs to be replenished by fresh water.

Saint-Gobain Oberland AG enjoys role model status thanks to its reductions in furnace emissions, heat recovery from exhaust gases, and the introduction of closed water cycles.

Energy

Energy circuit

Seventy four percent of the total energy required for glass manufacture is needed for the furnace. Of this 74 % about half is bound within the glass, some is recovered from the exhaust gases and used for electricity production, while the rest is lost.

The high proportion of energy that is bound up in the glass explains the considerable energy saving that occurs when recycled glass is melted down.

Heat recovery

Waste heat recycling

Taking advantage of all the energy-saving options and regenerative chamber energy recovery produces an optimum energy yield with the lowest possible emissions. High-temperature process exhaust gases, as produced by the furnace (1590 °C ), provide a perfect opportunity for the efficient use of waste heat.

At the Bad Wurzach plant owned by Saint-Gobain Oberland AG, heat recovery - following an exhaust gas temperature reduction to 400 °C (via a heat exchanger with downstream steam engine and generator) - provides for continuous in-house process water heating and electricity generation.

Exhaust gas purification

Waste gas abatement

Flue gas cleaning using electrostatic filters has led to a reduction in emission values previously unattainable in container glass production. These days values are frequently well below the prescribed limits for emissions. Dust which is filtered out is fed back into the cycle and added to the glass melt.

Multi-use industrial packaging

Ecological cycle

And it’s not just our glass packaging that’s returnable and recyclable, the packaging used during transport and storage en route to the bottling plant is too. These days all our packaging consists of just 3 separate elements:

  • a transport pallet and
  • Öko-Pack Plus tray, supplied from a pool,
  • and clear polyethylene film wrap which is subsequently separated and forwarded to a recycling 
  • company.