In series production of plastic components, there is a point after which every correction costs many times more than at the design stage. That point is the machining of the first mould inserts. Moldex3D simulation is our tool for pushing that point as far to the right as possible - so that by the time the mould is mounted in the machine, the vast majority of decisions have already been made and documented.
Below are six areas in which simulation has a real impact on project time and cost. These are not textbook generalities - all of them come from projects we have run over the last twelve months.
01 · Gate location
The customer does not always have freedom in choosing where the gate will be. We routinely rule out the visible side, as well as functional surfaces. Moldex3D lets us iterate through placement scenarios - with a focus on fill balance and fibre orientation in reinforced materials.
In one of our recent projects for the bus industry, moving the gate by 38 mm eliminated a weld line in the screw mounting area - without having to change the ribbing on the technical side.
02 · Shrinkage, distortion and warpage
These are probably the most frequently cited benefits of simulation. In practice, their value lies not in calculating the number itself, but in understanding where a given warpage comes from and which process variable needs to change to minimise it.
For a typical PA6.6 GF50 component, we check at least four scenarios:
- different injection directions (fibre orientation effect)
- four cooling configurations (different channel layouts)
- two holding pressure profiles (time and value)
- two thickness variants at critical nodes
Four scenarios · four decisions. Each one made before the steel is cut.
03 · Air traps and weld lines
Weld lines in cosmetic components are an obvious issue. Less obvious are air traps under ribs in deep pockets - these can force the process engineer to raise holding pressures beyond reason and, as a result, shorten mould life.
“The cheapest vent is the one you don’t have to design, because you know it will never be needed.” - senior process engineer · MS-PROGRESS team
04 · Machine selection and initial settings
Simulation gives us a realistic process window even before the first trial. We know what clamping force is needed, what range the injection speed profile should stay within and how much of the cycle cooling of critical areas will take. This lets us select a machine from our fleet (we have 36 machines from 25 to 650 t) without the risk of having to move the mould to a larger press after trials.
05 · Cooling optimisation
The larger the share of cooling time in the cycle, the more important it is that this time actually does its job. In our practice for defence and automotive components, a review of the cooling channels with an analysis of the temperature gradient in the mould walls is standard - because an eight-second difference in cycle time on a 12 M pcs/month run means real money and real orders this quarter.
06 · Dialogue with the toolroom
This point is not technical - but it is the most important. The Moldex3D report is a common language between our designer and the toolroom (domestic or Asian). Decisions are made on the basis of data, not the intuition of a “mould master”. Time spent discussing tool changes drops by days - sometimes weeks.
What this means in numbers
On average, for projects we run from brief to PPAP, simulation reduces:
- the number of mould iterations by ~30% (typically from 3 to 2 trial inserts)
- the time from “first trial → acceptable trial” by ~25%
- the risk of major tool modification in the post-PPAP phase - drastically
These are figures we are happy to revisit with the customer during the project - and they are the best argument in any discussion about start-up costs.
When it's not worth it
Simulation costs engineering time and licences. For simple injection-moulded components - a single wall, one gate, unreinforced material - you can consciously skip it. But for anything with a thin-walled feature, fibre-reinforced material, cosmetic requirements or critical assembly tolerances, there is only one answer.
