By Ebele Orakpo

USE what you have to get what you want, is a popular phrase among women of easy virtue but in recent times, the phrase has been given a positive connotation in Nigeria. At the Nnamdi Azikiwe University, Awka, a lecturer in the Mechanical Engineering Department, Dr Ugochukwu Okonkwo, led his students to build various car body components from agricultural wastes as part of their course requirements. They used raw materials such as cashew nut shell liquid, resin reinforced with palm fruit bunch refuse fibres etc. In this chat with Vanguard Learning, Okonkwo who is also the Deputy Chairman, University/Industry Research Committee, speaks on the project.

Excerpts:

The problem:

Okonkwo

The car industry uses materials such as iron, aluminium, copper, steel, plastic steel, glass, rubber, petroleum products etc., to build cars. Most of the weight of vehicles comes from steel. According to a report in Financial Week, ‘in 2007, the average car contained about 1,090kg of steel, and the average pickup truck or SUV used nearly 1,360kg of steel. Most cars now weigh around 1,360kg, and most SUVs weigh around 1,810kg.

Apart from the cost, weight of vehicles and the problems associated with it, the fact is that Nigeria is still struggling with its steel manufacturing plant and is not yet producing iron and aluminium in large quantities, hence, the need for viable alternatives.

Today, most door beams, exhausts, roofs and body panels are made of steel. Also, a report by the American Chemistry Council says that plastics make up about 50 per cent of the construction of new cars today because “plastics are durable, cheap and can be turned into just about anything. Dashboards, gauges, dials, switches, air conditioner vents, door handles, floor mats, seat belts, airbags, etc., are all made from different types of plastics.

Because of their lightweight, plastics are being increasingly used in body structures and in engines.” If Nigeria cannot manufacture the whole vehicle, it can at least produce some parts using its abundant natural resources.

Solution:

According to Engr. Okonkwo, “the need to reduce the weight of vehicles because of the problems and costs associated with it, led us to find alternative, more sustainable materials. This will also reduce the cost of fuelling. “We utilised available resources like palm bunch fibre, coconut fibre, cashew nut shell liquid and some other fibres to produce car body parts.”

Products:

“We are not only considering the design of the aesthetics, we are also involved in designing the aerodynamics of the vehicle in question. We have produced bonnet/hood, front and rear bumpers, fenders/side panels and car doors. We are also making it really scientific, optimising the production processes using well advanced scientific methods in optimising the variables because when you talk of fibre orientation, you talk of fibre size, length and some other variables that may need to be tinkered around to get the optimum that will give the best result.

“We are using response surface methodology, we used Taguchi methodology in our designing processes and we have gotten some good results after carrying out mechanical tests like flexural, tensile, energy absorption tests and so on, and we are getting good results that are comparable to what we have now in the market and having the advantage of sourcing it locally is a plus.”

Raw materials/ method:

Palm fruit bunch refuse fibres were used as reinforcement in some of the parts while woven raven glass fibres were used in others. Cashew nut shell liquid was used as resin in some while in others, polyester was used.

The preparation of the fibre/reinforcement and the resin which includes extraction, processing, treatment, characterization, design, fabrication etc., were carried out. Static mechanical properties of the composites such as tensile, flexural, electrical and heat conductivity and water absorption tests were carried out.

The work exploits the potentials of the abundant resources from plant wastes for use as fibres in reinforced composites. It also identified various independent variables like fibre content, fibre size, fibre orientation; fibre treatment that can impact on the desired dependent variables.

“Hence, optimization of targeted properties can easily be carried out using well designed experiments like response surface methodology or Taguchi method,” he said, adding that they hope the study will “open the way for future investigations in the use of various fibres that we have in abundance and the potential application widened.”