A CAREER IN PLASTICS TECHNOLOGY
A plastics technologist works with the manufacturing of raw materials, the conversion to and quality control of final plastic products.
NATURE OF THE WORK
The plastics industry is very closely linked to the chemical industry, as its raw materials are chemicals mainly derived from oil, coal or natural gas.
A plastics technologist can be employed in different areas of the plastics industry and the nature of the work will differ considerably. The common areas are:
Plastic raw materials industry
The production of raw materials is the starting point of the whole manufacturing process. A technologist is involved in the supply, production, research and development of raw materials.
The finished product is made by a wide variety of processes from the raw material supplied.
The main conversion processes are:
Injection moulding: This method is probably the most frequently used method of moulding plastics. Raw material is fed into a heated barrel, pushed forward by a rotating screw, softened by heat and injected into a mould. The part cools in the shape of the mould, is ejected and the cycle repeated. Products are consumer items such as containers, pens, bottle caps as well as hubcaps, bumpers and swimming pool cleaners.
Blow moulding: This process is used for the manufacture of hollow articles such as bottles and containers. A tube is extruded vertically downwards and, while it is still hot and pliable, a two-part mould closes around it, closing off the bottom end of the tube. The plastic tube is inflated with air till full contact with the cold mould is established.
Film blowing: A molten plastic tube is extruded through a circular gap. The thin molten plastic tube is formed to size and thickness by a big air bubble that is maintained inside the tube. The thin film can be made into plastic bags.
Extrusion: The plastic raw material is fed into a heated barrel and pushed through different dies by a helical screw to form long continuous products such as pipes, gutters, hoses, sheets, monofilaments and window frame profiles. The hot products are cooled by air or water and coiled or cut into lengths that can be transported.
There are many more conversion processes such as reaction-injection moulding, casting, calendering, foam casting, rotational moulding, filament winding, etc.
Important facets of the manufacturing process are process development, quality control and production management. The work can also include design of new articles, design of the moulds and the machinery to make the products.
This is where a plastics technologist plays an important role. This job entails the evaluation of polymeric compounds and products, the compilation of specifications and liaison between the raw materials manufacturer, the converter and the end user.
A plastics technologist may also be involved in market research, product development, technical supervision, production, sales, administration and advertising, as in any other industry.
A technologist can work either in the laboratory or on the shop floor, and qualifications together with suitable experience can lead to promotion, to higher levels of responsibility and to management.
A plastics technologist must have an interest in and an aptitude for technical and scientific work. He/she must have an attentive, inquisitive and patient nature, as some experiments have to be repeated numerous times. Management skills are important for promotion purposes.
A Matric Certificate with mathematics is the minimum entry requirement for the diploma course. Matric exemption with mathematics and science is required for a BSc degree.
The University of Stellenbosch offers a BSc (Hons) degree in Polymer Science. The student must have either a BSc or a BEng (Chem.) degree with chemistry, physics and mathematics to be admitted for this postgraduate course. The duration is one year full-time or two to four years part-time.
The National Diploma in Plastics Technology is a three-year sandwich course, or three semesters full time together with three semesters on-the-job training. The Cape and Port Elizabeth Technikons offer this course. Subjects include physics, organic chemistry, plastics technology and statistics. The Pretoria Technikon offers a Higher National Diploma as well.
Plastics|SA offers training on raw materials, the various plastics processes, etc. For more information on their training courses, contact Fhatu at (011) 314 4021.
The plastics industry is a fast-developing and dynamic industry. There are approximately 35 000 employees working in about 1 700 companies in South Africa. New applications for plastics are continuously being found. This requires the developing of processes and materials and provides an ongoing challenge to a plastics technologist.
Enquiries can be addressed to:
• Institute of Polymer Technology
Pretoria Technikon, Private Bag X680, Pretoria, 0001
Tel (012) 841 4972, Fax (012) 841 4924
• Institute of Polymer Science
University of Stellenbosch, 7600,
Tel (021) 808 3172, Fax (012) 808 4967
Private Bag X68, Halfway House, 1685
Tel (011) 314 4021 Fax (011) 314 3764