Master redox and fining, the key to consistent quality and performance in glass production.

Redox is a critical factor throughout glass production, affecting melting, fining, foaming, seed development, and color. This course will equip you with the skills to quickly identify and resolve redox-related issues, ensuring consistent glass quality, clarity, and color. Learn to monitor and control the redox state at every stage, from batch to finished product.


You should attend if you are interested in:

  • Defining and understanding redox:
  • Batch redox number
  • Relations with oxygen partial pressure and temperature
  • Optical measurements on the glass
  • Glass color: amber chromophore, reduced green, decoloration
  • Radiative heat transfer
  • Sulfur solubility in the melt
  • Fining principle and mechanisms
  • Mechanisms and root causes of foaming
  • Cullet and redox control
  • Identifying the origin of seeds and bubbles


What you take away:

  • Know how to optimize your batch recipe and monitor your raw materials to obtain a satisfactory redox
  • Know the available technology to track the redox state of the melt in the furnace
  • Identify the ideal fining conditions for the manufacture of glass
  • Quickly troubleshoot process or quality concerns (e.g., foaming, energy consumption, color, seeds, bubbles) and detect redox issues

Your trainers

Sjoerd Stelwagen

Sjoerd Stelwagen studied Chemical Engineering at Eindhoven University of Technology. Directly after his study he started as a Technical Specialist at the Furnace department of Ardagh Glass in Dongen, The Netherlands, where he later became Batch and Furnace Manager. He then evolved as EHS manager for the Benelux plants. With more than 16 years of practical glass making experience, he joined CelSian in 2021 to work as a project manager and trainer.

Cristian Hernández

Cristian Hernández graduated as a Materials Engineer from the University of Antioquia, Colombia. Then he obtained a Master’s degree in Metallurgical and Materials Science at the University of Sao Paulo, Brazil. He worked for 8 years as a Glass Science engineer at OI for different plants in South America, supporting them in color changes, glass quality issues, furnace and batch house ramp-ups, raw materials standardization and implementation of new ones. He joined CelSian as a Project leader acting as a supporter and technical advisor.


Training costs € 1800- per participant

Price excludes tax and duties.