Plastics manufacturing expert talks new classifications in materials design

Materials World magazine
5 Jan 2016

Plastics manufacturing expert Igor ˇCati´c argues for a new classification in materials design to take into account the rise of digital processes.

Professor Emeritus Igor  ˇCati´c has been a fellow of IOM3 since 1978. He made his Doctoral thesis at Institute of Plastics Processing in Aachen, Germany. After 10 years working in the field of mould and machine design for plastics, he moved to the University of Zagreb Faculty of Mechanical Engineering, Croatia in 1965. His most important contributions in plastics and rubber are Heat exchange in moulds and Systemic analysis of injection moulding. He is a recipient of the SPE International Education Award (1998). He also publishes original papers in language and philosophy

Historically, the development of materials has been based on transforming an idea into a material by experiment. Meanwhile, rapid development of computers and other technologies has enabled significant changes in the materials world, specifically in methods of production.

One manufacturer of equipment for additive manufacturing stressed to me that they developed a number of ‘digital materials’ and this led to the need to study the contemporary meaning of the word material.

The word material has a very broad meaning covering two main groups. The first, raw materials from which stuff, things, matter is constructed or manufactured. The second pertains to writings, documents, archival materials or conference papers, etc. 

New acronym - CADM

During our synthesiological research, the theory of systems is used. Based on the results, we have developed the idea to classify material according to one of three basic criteria – mass, energy and information on which all of us depend. This is supported by A G Oetinger (1984) who said, ‘Without materials, there is nothing. Without energy, nothing happens. Without information, nothing makes sense.’

So we conclude that the first group of materials can be called physical or analogue. The second group is information materials with two subgroups – analogue information and digital information.

Digital materials only exist in a computer, and this gives us a new idea. During the development of a product, from the idea to the finished part, we have previously used two acronyms – CAD (computer aided design) and CAM (computer aided manufacturing). But there is a missing link between CAD and CAM. We propose CADM (computer aided development of material). By introducing this acronym, a completely new field of research is opened. However, insufficient care is paid to one very important fact. 

Why should there be a distinction between materials and products made of certain materials?

For analysing development and production of materials and products, there are three basic terms for the common names of natural technology and artificial (man’s) technology – substance, material and product. 

The way of transforming the substance into usable products can be twofold. From raw materials, such as natural gas, we can make polyethylene (processing technology). Using methods of primary shaping (manufacturing technology) we could make a polyethylene box from this material. The same is true, in principle, for making metal products. In this case we use the acronym CAM.

Another way is to make the material in the same place (in-situ) – from a compound (such as rubber) comes the required form of a product (primary shaping) with form solidified by a chemical reaction – for example, polymerisation and/or crosslinking such as in a thermosetting product. It is therefore a combination of a manufacturing technology and a processing technology. According to Gunter Ropohl (1979), this product is a result of production (fabrication) technology and the acronym should be CAPR (1989).

What is the specific feature of these two ways of making a product? The conversion of natural gas in the polyethylene produced a visible, formless material which is then converted into a finished product. In the second case, there is no independent material, but a product made from this material. Therefore, it is possible to testify that certain materials do not exist independently (ceramics or rubber materials), and therefore require applications of production on the properties to obtain the finished product.

A new way for developing materials

In developing a new material there are two possibilities. First, the classical composition of required material, which can be very expensive. The recipe was usually stored on paper (analogue information material). Today, computers allow the development of computer-based recipes - the previously mentioned digital material. In both cases, it is the information which serves to determine a variety of ingredients for the necessary product. No matter how the recipe is composed (analogue or digital), it is followed by the creation of physical products.

Education for the CADM era

The proposed CAD-CADM-CAPR, or CAM, chain is a new scientific and engineering field, demanding a strong change in education. Information technology and education in materials are just preconditions. Today products are made at once from different materials or, in the future, a combination of living and non-living. The products from digital material can be manufactured from analog materials (CAM) or mostly produced from a combination of substances (CAPR).