Critical issues in glass chemical strengthening


Part One – Fundamentals of Ion Exchange for glass strengthening : the workshop will be initially addressed to  glass strength  issues and to the strategies to increase glass strength by the introduction of residual stress. Fundamentals of ion exchange from a scientific perspective  will be focused with the purpose to understand how residual stresses are generated and how they can be predicted by mathematical models.  Relaxation effects relevant to glass strengthening by ion exchange will be discussed and introduced.

Part Two – Ion Exchange process conditions and technological issues:  the second part of the workshop  will be more related to process conditions and, initially, it will be discussed the relevance of glass  chemical composition and of  molten salt bath contamination to the glass strengthening final results. Technological aspects related to process and plants implementations and process control will be finally introduced and discussed.

Methodological note – Each topic indicated in the ”Bullet Point summary” and in the “Workshop timetable” will be initially introduced and outlined by the organizer with a presentation, the discussion for each argument will be opened to the workshop participants. Exercises and case studies will be proposed and discussed by the organizer.

Bullet Point Summary

Workshop Timetable

• Basic of glass strength issues

• Strengthening by introduction of residual stresses

• Physics and chemistry of ion exchange

• Residual stress profile resulting from ion exchange

• Relaxation effects

• Relevance of glass chemical composition (Soda Lime, alkali aluminosilicate)

• Relevance of ion source (molten salts) contaminations

• Technological issues (Plants and implementations)

• Process control



09.00 Speaker and participants introduction

09.15 Part one – Glass strength issues and glass strengthening by introduction of residual stresses

10.00 Part 1. Physics and chemistry of ion exchange: residual stress profile build-up by ion exchange

11.00 Part 1. Relaxation effects

12.00 Lunch break

13.00  Part 2. Relevance of glass chemical compositions and ion sources contaminations

14.00 Part 2. Technological issues: plants and implementations

15.00 Part 2. Process control

16.00 Discussion and conclusion

17.00 End of the workshop

Duration: 8 hours


Guglielmo Macrelli

Guglielmo Macrelli, Isoclima SpA

Guglielmo Macrelli is a senior scientist at Isoclima SpA – R&D Department. He has a background in physics and chemistry. He has been active since 1990 in many glass science areas: ion exchange in silicate glasses, thin film optical coatings and glass mechanical properties. He has a long time (more than 25 years) experience in research and development and plant production control for chemical strengthening of silicate glasses by ion exchange. He has an extended experience in laboratory testing and measuring for glass strength and residual stress in glass and he authored a number of scientific papers and conference presentations. He organized workshops on this topic in the past two editions of GPD (2013, 2015). Guglielmo Macrelli participates to standardization drafting groups in both ISO and ASTM and he is member of the American Ceramic Society.

Download PDF Brochure

PDF Brochure GPD Finland 2017 Workshop Glass Chemical Strengthening by Ion Exchange


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