Inorganic binders

In addition to clay minerals, which have been used for decades as a binder for the compaction moulding process (with bentonite moulding materials), there are also inorganic chemically curing binder systems od long-standing tradition in the foundry. Since the forties of the last century cement has has been used for mould and core production. The core production was then revolutionized in the fifties by the water glass CO2 process. Since the Fifties, theclassical inorganic systems have superseded the organic binder systems, with notable increase around the 1970s and 80s. Due to a constantly increasing environmental awareness in the foundry industry, which has been increasingly underpinned by government calls for an improvement in casting production, the almost forgotten inorganic binder systems had a renaissance at the turn of the century. There is some misleading and even conflicting information surrounding the current state of the application, as well as its achievable property level. Therefore, this book should be attempted as complete as possible. It is aiming to provide answers to the question of what can afford inorganic binder systems at the present. On the other hand this book should open questions or problems to be solved for a further increasing of proportions in mould and core production in the coming years.

Auteur

Dr. Eng. habil. Hartmut Polzin is working on the Foundry Institute of TU Bergakademie Freiberg. His research focuses among others on the area of inorganic binder systems. After studying foundryment in Freiberg he received his doctorate in 1999 with a dissertation on microwave hardening of water-glass bonded foundry moulding materials to Dr. Eng.
After several years working in a foundry, he returned to the Foundry Institute and is responsible for teaching and research in the field of moulding materials and moulding processes since 2008.

Contenu

Foreword
1 The Beginnings of the Application of Inorganic Binder Systems
2 The Development and State of the Application up to the Year 2000
3 Overview of Currently Available Inorganic Binder Systems
3.1 Alkali silicate binder (water glass binder)
3.2 Silica Sol for Investment Casting
3.3 Cement as a Binder System
3.4 Geopolymer Binder
3.5 Salt Binder Systems
3.6 Gypsum as Binder
4 Classification of Moulding Processes with Inorganic Binder Systems
4.1 Hardening by gasification process
4.1.1 Water glass CO2 process
4.1.2 Water glass warm-air process
4.1.3 Warm air drying in water glass powder systems
4.2 Cold self-curing processes
4.2.1 Cement moulding process
4.2.2 Water glass ester process
4.2.3 Geopolymer process
4.3 Warm or hot curing processes
4.3.2 Microwave drying method
4.3.3 Processes with salt binder systems
4.3.4 Investment casting with silica sol binders
5 The Use of Alternative Moulding Materials
The use of alternative forms of moulding material with inorganic binders
Water glass CO2 process
Water glass ester process
Water glass hot box process
Hot distortion (hot formability)
Summary
6 Reclamation of Used Sands
Basics of reclamation
Mechanical or pneumatic reclamation
Thermal reclamation
Wet reclamation
Reclamation of inorganically bonded moulding materials
Summary of reclamation process
7 The Influence of Inorganic Binder on Clay Bonded Circulation Moulding
Materials
Imprint