To develop a good CAIMDS, an analysis of ‘what they have’ and ‘what they want’ needs to be performed。

What they have:

– The customer’s requirements for the product。 This includes the detailed geometry and dimension requirements of the product。

– An existing mould design library。 This library covers the standard or previously designed components and assemblies of the mould design, for example, the mould base (the fixed half and the moving half) and the pocket (the fixed half and the moving half)。

– An expert knowledge in injection mould design。 Expert knowledge of both initial and detailed designs for the injection mould is obtained mainly from experienced mould designers。 Such knowledge includes material selection, shrinkage suggestion, cavity layout suggestion and others。 

What they want:

– An intelligent and interactive mould design environment。 

Mould design is often composed of a series of design procedures。 These procedures usually require certain mould parts to be created and existing mould

parts to be assembled。 Such a mould design environment need not be fully automatic, especially for complicated products with many undercuts。 An intelligent and interactive environment will be a good choice to integrate some useful automation algorithms, heuristic knowledge and on-line interaction by the experienced mould designer。

– Standard/previous designed components/assemblies (product-independent parts) management。 Apart from the core and cavity, an injection mould has many other parts that are similar in structure and geometrical shape that can be used in other injection mould designs。 These parts are independent of the plastic mould products。 They are mostly standard components that can be reused in different mould designs and mould sets。

– Useful tools (including solid design and analysis calculation) in the core and the cavity (productdependent parts) design。 Geometrical shapes and the sizes of the core and cavity system are determined directly by the mould product。 All components in such a system are product dependent。 Also, these parts are the critical components in the mould design。 Their geometrical requirements may be complicated。

Thus, some tools developed to design the core and the cavity based on partial automation and partial interaction can be quite useful。

– Design for assembly。 In conventional CAD/CAM systems, moulds are represented and stored as a complete geometric and topological solid model。 This model is composed of faces, edges and vertices in a three dimensional (3D) Euclidean space。 Such a representation is suitable for visual display and performing geometrically computation-intensive tasks such as engineering analysis and simulation。 However,

this form is not appropriate for tasks that require decision-making based on high-level information about product geometric entities and their relationships。 Mould designers prefer a design for assembly environment instead of a simple solid model environment。 This idea is also presented in Ye et al。’s work [24]。

– A design for manufacture。 A complete injection mould design development cycle can be composed of the mould design and mould manufacturing process。 To integrate CAD/CAM into the mould design, the  manufacturing features on the mould should be abstracted and analysed for the specific NC machine。 Both the process plan and the NC code should be automatically generated to enable the final designed mould to be manufactured。

– A design for engineering drawings。 For many companies, the injection mould design has to be represented in the form of engineering drawings with detailed dimensions。 CAD/CAM tools that are able to automatically generate these engineering drawings from the final injection mould design will be useful。 Based on the above analysis, our research focus is to develop techniques to represent ‘what they have’ and ‘what they want’。 Representing ‘what they want’ is actually the representation of the knowledge and injection mould object。 Developing ‘what they want’ means to integrate the representation with intelligent and interactive tools for the injection mould design into a completed design environment。 Therefore, an IKB-MOULD is proposed for mould designers to realise the above two requirements。