Precious metal preparations for lead crystal

1. Precious metal preparations for lead crystal • Precious metal preparations for lead crystal • XIV Technical Exchange Conference Waterford, Ireland • October 12 th – 14 th 2002 • Annette Lukas/ Ceramic Colour Division Heraeus Germany

2. Precious metal preparations for lead crystal • Organization of the precious metal preparations • Technical information

3. Organization of the precious metal preparations • 1.1 Organization of the precious metal preparations due to their type of decoration • In general, there are three main types of gold decorations and the luester decoration: • bright gold • silk-matt gold • burnish gold • luester

4. Organization of the precious metal preparations • 1.2 Types of application • by brush • by screen printing • neoprene wheel machines • pad printing • other well-known application techniques

5. 2. Technical information • 2.1 Composition of precious metal preparations • 2.2 Layer strength • 2.3Firing • 2.4 Oxidation reaction • 2.5 Dishwasher durability 2. Technical information

6. 2. Technical information • 2. 1Composition of precious metal preparations

7. 2. Technical information • 2. 2layer strength • According to the thickness of the layer the following points are important for • mechanical resistance of the precious metal decoration • dishwasher durability • tendency of oxidation reaction of the fired layer • fire stability • (sometimes the reverse side view)

8. 2. Technical information • 2. 3Firing • During the firing process the following points are influenced • mechanical resistance of the precious metal decoration • dishwasher durability • tendency for oxidation reaction of the fired layer • n the reverse side view of the precious metal decoration

9. 2. Technical information • 2. 4oxidation reaction • If there is a lot of silver in the precious metal film, the chance of getting this problem increases. • The silver is responsible for the yellow colour shade • As a result of different effects there is a tarnishing of the decoration

10. 2. Technical information • 2. 5 dishwasher durability • 2. 5 .1 What does dishwasher durability mean and which test procedures exist? 2. 5 .2 How can the dishwasher resistance be improved using materials of modified chemical composition?

11. 2. Technical information • 2.5.1 What does dishwasher durability mean and which test procedures exist? • 4 Dishwasher durability is a function of : • Chemical durability (attack of alkali and complexing agents + attack of acids) • Mechanical durability (rubbing and scrubbing of parts caused by vibration and water pressure)

12. 2. Technical information • 2.5.1 What does dishwasher durability mean and which test procedures exist? • n There are no reliable standards existing for dishwasher durability • n Many (company specific) • standards are used but • they are not comparable • to each other

13. Defined Parameters: type of dishwasher machine cleaning- temperature cleaning-time chemistry of detergent type of decoration Undefined Parameters: inhomogeneous firing- temperature in decorating kilns inhomogenities in glass surface position of glass in dishwasher machine 2.5.1 What does dishwasher durability mean and which test procedures exist?

14. 2. Technical information • 2.5.2 How can the dishwasher resistance be improved using materials of modified chemical composition? • It´s a coordination between the glass and the complete precious metal preparation. That means: • The organic and inorganic components of the precious metal preparation plays an important role in combination with the composition of the glass and firing.