Initial Situation:
Many sectors of industry are now increasingly using products made from liquid silicone rubber (LSR), thanks to its superior material properties compared with thermoplastics. For example, LSR can withstand constant temperatures between -50°C and 230°C and the mechanical properties of the rubber remain virtually unchanged over the entire temperature range. LSR also boasts almost constant electrical properties, outstanding ageing characteristics and weather resistance, as well as ozone and UV stability, plus additional adjustment options, such as oil bleeding (self-lubrication), reduced flammability, increased transparency and increased Shore A hardness. This means that LSR can be used in countless applications.
Goals:
However, when it comes to moulding LSR, these material characteristics still pose a huge challenge. Manufacturing injection moulds currently requires expensive and time-consuming iteration loops, which would not be needed with a design process that allowed new moulds to be designed correctly first time round. In addition to increasing efficiency significantly, this would also improve the use of materials in many other areas and components.
The goal of the project is to find a way to build efficient vacuum-free LSR injection moulds right the first time.
Process:
To achieve this goal, the first step is to develop a design and simulation workflow that makes use of mechanical, thermal, fluid mechanical and reactive simulations especially for LSR processing. The objective is to increase efficiency using an innovative combination of very low thermal inertia and variothermal, conformal fluid temperature control and to use precise integration control to ensure that the LSR can self-seal the mould so that a vacuum is no longer needed. This means that moulds built using the new process will have a much shorter cycle time, consume less energy and boast a much longer service life.
