Tool making plays a crucial role due to the imaging nature of this process. Every micro-defect, every shape deviation is reflected on the surface of the glass. There are therefore the strictest of requirements on the quality of shape and surface. Molding tools must also be capable of withstanding high loads at varying temperatures of up to 800 °C. Only high-performance materials can meet these requirements.

Today, Aixtooling is focusing on the use of very fine-grained hard metals characterized by a very small proportion of binder. This allows their reactivity with the hot glass to be minimized on the one hand, and on the other these material properties improve workability to optical quality. The tool components in periodic contact with the glass must be highly heat-resistant, capable of withstanding changes in temperature, corrosion-resistant, and ideally good heat conductors. An extremely high density, that is, absence of pores, as well as a high degree of hardness or wear resistance is also useful. Only a few materials can meet all these requirements. Besides the hard metals already mentioned, selected high-performance ceramics can also be used.

Aixtooling has extensive experience with the precision and ultra-precision machining of these materials. Due to these brittle-rigid properties, only milling technologies with geometrically undefined blades can be used. Mastery of this technique and its adaptation to the particularities of a given processing task is a core competence of Aixtooling GmbH.

Coatings refine tool surfaces and lengthen lifetimes

Since even the materials described above tend to undergo reactions with the hot glass in the vicinity of the press, certain coating systems must be applied for most applications. Since the coating is at the end of the process chain, but directly in the active zone of the active molding, it is extremely important.

Together with different partners ? including Fraunhofer IPT, the Institut für Oberflächentechnik IOT, and the Würselen company Cemecon GmbH ? it has been possible to qualify a coating system that can meet most of the requirements of isothermal molding in optical glass. Aixtooling thus has the capability of decoupling an important component of the fabrication chain from the Asian supplier market.

Our customers benefit from shorter supply times and high quality reliability in the application of coatings.