2013 Lightweighting Special : TAFE makes light of heavy metal

2013 Lightweighting Special : TAFE makes light of heavy metal Tractor major’s engineering plastics division makes headway in replacing aluminium and metal parts with high-performance plastics. Karthik H reports.

The Engineering Plastics & tool Division (EPD) of the Chennai-based Tractors and Farm Equipment limited (TAFE) has been making Charles Darwin proud for the last few years. The division has come to accept that certain technological advancements in the field of engineering plastics and composites – due to various factors ranging from cost to lack of suitable R&D to the notable hesitation from OEMs to take the dive into composites – will not be easily accepted in the Indian automobile market and has learned to adapt. With fuel economy playing a massive role in the end-buyer’s decision, OEMs have treaded this line very carefully. Hence, instead of developing injection moulding techniques of thermo plastics, TAFE’s EPD has channelled its resources into developing lighter materials for internal components, with much success. The division has won several TPM excellence awards for its injection moulded bumpers like cowl grille and front grille. The division’s work extends beyond bumpers to collaborating with customers on plastic product design and metal replacement. Through their design and manufacturing capabilities, TAFE’s EPD has products with variable wall thickness that can lead to around 20 percent reduction in weight. Future products lie in replacing aluminium and steel with plastic for thick-walled parts like grab handles and pillion handles. The EPD’s clientele includes Indian affiliates of multinational companies such as Mitsubishi, Ford, Renault-Nissan, Lear, Toyota, Behr, Toyo, Johnson Electric, Visteon, Kyoto, GE, Johnson Controls, Bosch, Hanil, Modine Thermal Systems, apart from a number of Indian companies like TVS Motor Co and Subros and in various sectors. However, the strength of this division lies close to TAFE’s interests. The division has been successful in replacing crucial tractor parts like fuel tanks, bonnet mesh, fender extension, toolbox, instrument surround bits for a hefty weight reduction of around 60 percent. The effect of replacing a metal fuel tank with engineering plastics goes beyond mere weight reduction to affecting the design language. Where previously the portion containing the metal fuel tank was designed keeping the tank as a constant, thanks to the flexibility of engineering plastics, fuel tanks are being moulded to fit the odd gaps in a tractor’s design, giving immense freedom to the designers.

Art to part

The EPD’s unique manufacturing language, called 'Art to Part', deals with taking the initial product from the 3D modelling phase till the end in the least expensive path. With networked CNC machines, automated shop floors and mold presses, the Art to Part venture has helped the division maintain both quality and cost competitiveness. Established in 1987, the division has catered to various sectors including IT hardware industry from its two facilities, one each in Chennai and Bangalore, with expertise in injection moulded thermoplastics, plastic injection moulds, jigs and special fixtures. A wide range of engineering plastics in various filled and heat resistant grades are processed in state-of- the-art microprocessor controlled injection moulding machines, with clamp capacities ranging from 40 tonnes to 4,000 tonnes. The machines are fitted with centralised material feeding systems and product take out devices. The EPD’s tool room is equipped with CNC vertical milling machines and CNC electrical discharge machines which can manufacture moulds suitable for clamp capacities up to 4000tonnes. Weight reduction, like in the real world, doesn’t come cheap. While engineering plastics and aluminium form the not-so-expensive option, carbon fibre and titanium occupy the other end of the spectrum. Each material has its own pros and cons. For instance, Ferrari has been adamant in not adapting carbon fibre for its road cars and swears by aluminium, stating that it results in better mechanical adaptability to the manufacturer’s designs. Other manufacturers, like Lamborghini and McLaren swear by carbon fibre. So it’s clear as day then, that the future lies solely on the economics of an OEM as there are multiple options available to gain that crucial advantage in weight.