Vulcanisation moulds: translating measurements into automated CAD geometry
I developed a calculation model for dimensional changes in elastomer seals and implemented it in a parametric Inventor/iLogic system. Seal dimensions and process factors provide the basis for adapting the mould geometry.
Project status: Calculation model and parametric CAD automation used in the design work at the time.
Schematic representation of the method
Initial challenge
An elastomer seal changes dimensions between vulcanisation, assembly onto a metal ring and press-fitting into its housing. The vulcanisation mould geometry therefore cannot simply match the desired final dimensions of the installed seal.
My contribution
I investigated these dimensional changes through measurements at different process stages and developed a theoretically grounded calculation model with empirical correction factors. I then transferred the model to a parametric Autodesk Inventor/iLogic system for adapting the mould geometry.
From measurements to a process model
The investigation covered dimensional changes caused by vulcanisation and subsequent cooling, expansion onto the metal ring and press-fitting. The resulting factors were linked to the seal dimensions, allowing the mould geometry required for the desired final dimensions to be calculated.
From the process model to a CAD rule
After the seal dimensions and process factors are entered, the iLogic system adapts the vulcanisation mould geometry. The engineering work therefore includes both developing the calculation relationship and transferring it to a reusable CAD model.
Benefits in design work
The approach reduced recurring modelling and drawing effort and reduced design rework on the moulds. Accounting for process stages when defining the geometry supported dimensional accuracy and reduced the need for further manufacturing and trial cycles.
Outcome and assessment
The calculation model, correction factors and parametric geometry formed an integrated tool for mould development at the time. The project demonstrates how findings on material and process behaviour can be translated into reusable design knowledge and an automated CAD application.