A water-based system for ceramic injection moulding

Water-based binders for injection moulding of ceramics use low moulding temperatures allowing moulding and die temperatures to be similar. Most of the binder system can be driven off as water vapour, cutting process time, reducing burn-out problems and causing less environmental pollution. The difficulties with removing moulded articles from the die must be over come. To address this problem, gel strength was measured on solutions up to 8 wt% of ten commercially available cellulose derivatives at four temperatures between the gel temperature and the boiling point of water. A paste with rheology that permits mould filling was made from the binder that showed highest gel strength. This was used in moulding trials. A similar formulation based on a low-strength binder was also studied for comparison. The paste bused on the highest gel strength binder showed significantly less. deformation on release from the die, allowing the processing advantages of the system to be realised. (C) 1996 Elsevier Science Limited.