Scientific moulding: parameters based on data, not on gut feeling

Scientific moulding is a method in which the settings for an injection moulding process are determined through controlled trials and measurement data. Not by estimation, nor by copying from a previous project. Every parameter has a demonstrable effect, and that effect is documented before series production begins.

Why guesswork is too costly

Many injection moulding processes are set up based on experience: choosing a starting point, making incremental adjustments, and seeing what the outcome is. This works when production is stable and raw material batches vary little. But with complex geometries, tight tolerances or high quality requirements, this approach is too costly.

A process based on guesswork is also difficult to transfer. Does the operator change? Does the raw material batch change? Then the adjustment process starts all over again. Scientific moulding eliminates that dependency. The process window is documented, not just in an employee’s head.

Four test sequences, a stable process window

Scientific moulding operates via four standardised tests, always carried out in the same order. Together, they define the process window: the range of settings within which the product meets specification.

• Viscosity study: determines the injection rate at which the material flows without degradation or overpressure.
• Cavity balance study: checks whether all cavities in a multi-cavity mould are filled evenly.
• Hold-pressure curve: sets the optimum hold pressure based on the part’s weight and shrinkage.
• Cooling study: determines the minimum cooling time at which the product can be ejected stably.

The outcome of each study is a documented range, not a single value. That range forms the basis for the production settings and for every subsequent run on that mould.

What repeatability means for your production

The greatest practical benefit is reproducibility. The same quality with a new batch of raw materials. The same quality with a different shift. The same quality after a planned maintenance shutdown.

This is not a given. Without a documented process window, every disruption is a reason to reset the machine. With scientific moulding, every disruption is manageable, because you know the limits within which the process is permitted to operate.

At Didak Injection, we define process windows as part of the technical dossier for every project. Clients who require auditable production processes receive this documentation as a standard part of our collaboration.

Scientific moulding starts with the mould

The method only works effectively if the mould has already been optimised for it. Sprues, cooling channels and venting points directly determine the outcomes of the four studies. A mould that has not been designed for measurable process control will present resistance during every test sequence.

When should you opt for scientific moulding?

The approach pays off for products with functional requirements, for large production runs where process stability has a direct impact on costs, and for customers who require auditable production processes. For simple products with generous tolerances, the investment in the study phase is not always necessary.

The question is simple: what is the cost of scrap or re-set-up time over 100,000 units? For high volumes, the answer is almost always: more than the studies cost.

Find out more about our engineering approach to custom moulding.