Warpage simulation with an innovative workflow to determine the tool pre-deformings

Simulation tools have been established in product development and tool making for years and reduce costs and development times. The goal of IMPETUS Plastics has therefore been for a long time to push the limits of simulation a little further, to improve the results and to further increase the calculation speed. With our continuous research and development work, we regularly provide innovative impulses for our customers.

RheoSim project launched

We are therefore very pleased to be able, together with our project partners the Institute for Plastics Processing (IKV), Kroma International GmbH and FAF Kunststofftechnik GmbH & Co. KG, we are very pleased to be able to push such an important topic as the optimal application of warpage simulation as an instrument for determining tooling requirements (RheoSim) forward within the framework of a research project.

Component distortion

Injection moulded parts are subject to shrinkage during the manufacturing process, i.e. the dimension of the component changes compared to the specified shape. The basic cause of warpage lies in local differences in the shrinkage of the material during the cooling phase of the component, e.g. caused by wall thickness jumps. Combined with the local stiffnesses in a component, the different shrinkage results not only in dimensional changes but also in changes in the shape of the component.

Tooling pre-deformings lead to high costs and deadline delays

If the moulding distortion cannot be kept within the specifications, consequential costs arise in the form of multiple necessary mould changes, time and travel expenses for coordination appointments between manufacturer and supplier, higher complaint rates up to recall actions or costly warranty services.

We all know from many projects that the time required for corrections to the injection mould to compensate for the moulded part distortion quickly exceeds the production time of the pure injection mould and has a direct influence on the release or final deadline.

A reduction in the necessary correction loops and the lead time required for the customer in the construction of injection moulds with mould reservations therefore directly results in a noticeable reduction in costs and time savings.

Innovative workflow for cost and time reduction

Impetus Plastics has therefore initialised an innovative workflow in the warpage simulation to determine the mould lead time. The solution outlined by the project partners – warpage simulation in combination with tool pre-deformings and with 3D measurements – will be methodically developed together in the research project and will lead to significant improvements in the use of tool pre-deformings.

 The focus of the project is to ensure that suitable measures can be introduced as early as possible – i.e. before the mould is built and before real components are available – to reduce warpage and the risk of components that do not meet the specification. Ideally, the geometry of the injection mould is already designed in the construction so that the components correspond to the desired drawing dimension after complete cooling, so that series production can begin on schedule.

The research project, for which the starting signal has just been given, is being funded by the Federal Ministry of Education and Research (BMBF) for two years. We look forward to working with our project partners and thank the BMBF for the funding.

What are your experiences in the tooling of injection moulded components? We would be very happy to receive suggestions or discuss this topic with you.