Decision Support System for Designing with Polymer Materials – Current Challenges and Future Expectations - Efficient Decision Support Systems: Practice and Challenges from Current to Future - page 495

demands like application mode, and additional factors like supplier recommendation. The
designer has to envisage the production process, semi-product or product assembly, parts'
maintenance and evaluating the level of environmental influence, which is becoming
increasingly important due to global pollution. Thus, Design for X (DfX) methodology,
where X resembles the appropriateness for manufacturing, maintenance, service, etc.
(Huang, 1996), has to be considered. The field of plastic products' design is of special
interest regarding DfX, as the final product could be optimized for one or more domains of
its life-cycle (Kuo et al., 2001). Using DfX, the engineer is able to concentrate on the most
important domain within the life-cycle in order to provide an adequate product design
solution.
Usage of DfX is rational and rationale as it represents one or the first step in the process of
attaining optimal product design. Nevertheless, the designer still cannot expect any
adequate support from available computer tools in the form of recommendation or
guidelines when a material or technological procedure has to be selected. In order to
overcome this bottleneck, Knowledge Base Engineering (KBE) techniques have to be taken
into consideration, when developing an intelligent decision support system for polymer
products' design. The intelligent system model for polymer products' design represents a
new approach in design processing. The preliminary condition for knowledge-based
support to polymer products' design process is an adequate knowledge base containing
related, well organized DfX domain knowledge and relations.
3. Polymer materials
Conventional materials like metals and ceramics can be often substituted by others, more
suitable for certain types of product. Thus, polymers are reasonable alternative as they could
offer better characteristics for noticeable lower costs. Some of the advantages such as less
weight, lower material costs, cheaper mass production, recyclability, specific electrical,
isolative or, corrosive, etc. features, easier part joining (Kim, 2004), higher aesthetic values
(e.g. no dyeing is needed) or, easier production of precision products, are of major
importance in product development process.
For every scientific discussion it is important to clarify the terminology. Polymer literally
means many units so polymers are materials where units consist of chain like
macromolecules and are joined together through chemical binding. Furthermore, plastics
are materials usually composed of polymers refined with various additives like fillers, glass
fibres, and pigments which aggrandize polymers properties (Askeland & Fulay, 2009).
Despite of described distinction between polymers and plastics authors usually use both
terms interchangeably thus we adopted this idea in this chapter. Common classification of
polymers is in three major groups:
 Thermoplastics including commodity and engineering polymers
 Thermosets materials
 Elastomers divided on natural and synthetic
General structure of thermoplastics is flexible linear chains, which could be straight or
branched and direct the thermoplastics ductile behaviour. Characteristically for
thermoplastics is their ability to melt at heating therefore they are processed in final form
by heating at certain temperatures. Consequentially, they could be easily reformed and
recycled with the same operation. Thermoplastics are generally distributed into