Sunday, August 2, 2009



Challenged to improve the tire production process,Apollo’s engineers took the idea one step further,creating the blueprint for their dream factory of the future:

by P K Mohamed, N Pradeepkumar, Sujith Nair & Raghuraj Ananthoj,research, technology & design team, Apollo Tyres Ltd

(Published Tire Technology international in 2008)

It started one evening when a friend posed the question, “Why does your industry use such expensive equipment and complicated processes to make something as simple as a black and round load of rubber?” Another friend, the owner of a rubber plantation, joined in, saying, “Our rubber is a versatile material with great dynamic properties, but it seems like your manufacturing process is designed to downgrade the properties of the material.” A third friend, who works for an environmental non-governmental organization, joined the chorus with, “You guys need to think through your energy consumption. The amount of fuel you try to save by constantly bringing down the rolling resistance of the tire is clearly offset by the amount of energy used at the manufacturing stage.” These comments got the research, technology and design team at India based Apollo Tyres thinking about how to address these very real issues. It set itself the task of designing an ideal tire factory,one that would go beyond environmental regulations, one that would improve economy, contribute toward social responsibility, and enhance customer satisfaction, while being flexible, modular, and mobile, with efficient processes.

The team felt that, although dreams may sometimes be far-fetched, dreaming big is the only way to make some of it a reality. Tire factories have traditionally been highly labor-intensive, with special and critical manufacturing processes adding complexity, and requiring extensive human intervention. But a complete rethink and integration of various facets of the manufacturing processes and machinery selection could deliver a dream product. The philosophy would be that simpler is better, and the essence would be to do much more with less. The product and the process would be less complex, with an approach of simplifying and combining operations, and eliminating redundancies. The output of such a factory would be a dream product: structurally simple yet enduring, functionally superlative yet economical, and with an ability to exceed customer expectations.

Such a product would retain the virginity of its rawmaterials during processing and would not contain materials that were harmful or added no value. It would be built in a highly automated and precisely controlled assembly line, employing a pull system with no inventory in its entire value chain. From the processing perspective, retention of material properties is critical throughout a tire’s life-cycle, as it undergoes millions of flex cycles. It would be a minor miracle if this dream could be achieved, as no product is free from degradation through aging. However, precise control in molecular weight reduction and optimum homogeneity in compounds could deliver the best possible results. A conventional tire manufacturing process constitutes various stages, such as mixing, dipping, extrusion, calendaring, component preparation, component assembly, building, and curing.

Among these stages, mixing is very labor and energy-intensive, involving heavy equipment with high capital cost. De-linking or part removal of this area from the tire plant, and outsourcing raw material in a ready-to-use form, would reduce costs. For example, custom compounded rubber pellets could transform a plant from the conventional ‘black’ industry to a ‘white’ one, giving improved efficiency, lowest depreciation, and substantially reduced pollution levels. A tire is built as a complex composite with a multitude of components, making tire manufacturing a multistage assembly operation, with extensive human interventions potentially adding non-uniformities at every stage of the process. Reducing this complexity would be the greatest challenge, and a rethinking of tire design is essential for simplifying the structure. The number of compounds and components used in a tire could be reduced through special formulations, so that a single component could function differently in different areas by dynamically varying the stiffness properties, as per the load frequencies. Also, the tire could be made intelligent through the use of embedded chips, which would render it less dependent on tread patterns. Special compounds such as electro-active polymers could dynamically optimize the traction requirement and hence offer optimum rolling resistance and grip on all terrains. Simplifying tread geometry (non-uniformity) would naturally reduce vibrations and noise, as well as simplifying the molding process. Having simplified the product, the layout of the factory could become product-oriented rather than process dependent. This layout would seek extensions into all upstream and downstream operations; a perfect integration across the entire spectrum of the value chain, facilitating business partnerships with suppliers and customers. The factory location would follow a logistics-based topology, with suppliers brought to the input end of the plant, and finished products delivered to the customer’s doorstep.

The factory would follow a ‘satellite’ network, consisting of a central star unit, strategically located for easy access to supplies. This unit would be connected with various satellite units, which would carry out the process of tire production. The central unit would control the formulary and intellectual property-related information, and would respond to the satellite units based on a needs-based formula. The satellite units would be mobile, enabling them to reach customer locations quickly, whereas the unit would be set up for on-site production in the shortest possible time. Satellite production units would be built on the innovative 2F manufacturing system, an integrated modular manufacturing system combining the consolidation (forming) and the vulcanization (firming) processes. These are the true value processes in tire manufacturing. This system envisages ‘making the tire as it is’, with minimum deviation from forming to firming, so that tires would be perfectly uniform for performance requirements. The mobile satellite units would carry integrated modular stations for forming and firming, and a module for branding. The unit comprises essentially a multiplex feeder for compound feeding, and a special robotic arm to wrap the carcass material onto a toroidal drum.

Mold covers would be part of this module, which would firmly envelope the toroidal drum after the carcass wrapping. The compound would then be injected into the cavity to fill and insulate the carcass wrap. The mold clamping would be such that the required pressure would be developed within the structure for consolidation during injection molding.

The movable forming unit would then proceed to the firming modulefor vulcanization, using a microwave or electrical-heating method. The tire would then be transferred in the quickest time possible to the branding module, where quick laser engraving or stickers would be fused to the sidewall at ambient temperatures.

Once created, a robotic fuzzy logic arm would pick up the finished tirefor upstream delivery. With the entire process of manufacturing simplified, the chances of non-uniformities would be drastically reduced, if not eliminated. The range of quality monitoring systems, such as uniformity, balancing, and final inspection, could even be eliminated, as could the processing aids required in the compound, as there wouldn’t be any issues pertaining to tackiness or blooming, rendering the conventional recipe obsolete.

The entire manufacturing process would be environmentally friendly, based on minimal use of fossil fuels and the use of natural materials. For example, greater usage of epoxidized natural rubber and vegetable oils would replace carcinogenic petroleum-based aromatic oils. The utility of silica has already been proved, and it has exceptional advantages over carbon black in meeting the magic triangle. The green system calls for processing that is free of volatile organic compounds, and that eliminates carcinogenic materials such as nitrosamines, polycyclic aromatic hydrocarbons (PAH), and naphtha based cements and solvents. All these measures would ensure a low carbon manufacturing process, in turn reducing the cost of the product. A product-oriented layout has tremendous potential to reduce waste. In a process-oriented approach, operators focus on individual production efficiency, which could act against the overall efficiency of the plant.
In this dream factory, wastes such as overproduction, inventory, transportation, processing, movement, or defects would be eliminated in the value-engineered production line, as well as wastes caused by losses of energy, time, and effort.

The factory would practice just-in-time production, whereby each processor machine would operate based on demand from the immediate customerin a pull system, reducing inventory and overproduction.

This factory is designed with foolproof systems in every operation, leaving no room for mistakes. The operation and process flow would be made foolproof to make a process or safety violation impossible. Quality would be a way of life rather than a separate entity to be practiced, and policing of it would be a thing of the past in the entire value chain, from supply to delivery. Suppliers would be empowered to self-certificate, and could participate in decision-making in relevant areas. Joint research and empowerment with customers and suppliers could be practiced for better understanding of each other’s requirements. Breaking free of orthodoxy with flexible and flatter structures, the organization could continuouslymobilize minds for innovations.

Management structures would be designed to ensure executives have freedom in implementing and testing innovations. The need to changeconstantly, in tune with market dynamics, would be a key driver.The factory envisages information technology as the greatest enabler ofefficient operations. Every operation in the factory, including utility services, machine operation, conveyors, and transportation and servicing, would be controlled by a central intelligent unit integrated with the ERP system. Extensive use of simulation would be employed in product and process design, eliminating process trials. The customer logging in for his requirement would work as the trigger for all upstream processes, extending up to suppliers.

Intelligent sensors would be used in controlling the cooling, heating, and lighting facilities, which would work only when human presence is detected or the machines need it, resulting in energy savings. Information technology would make the factory a transparent entity by enabling real-time communication. Communication channels could be individual computers, mobile phones, or electronic display boards placed in prominent places, flashing information as and when required. An operator at any station could log in his feedback to receive a reply from management in real time, decreasing the need for physical meetings, and reducing interaction costs.

The primary goal that a dream tire factory must meet is to produce acustomized product for every single customer, as and when required. Sucha factory is based on the three pillars of economy, ecology and society. It needs to function as a facility which at no point should be in conflict with anything else in its immediate community. This is a dream, but work has begun to see how much of this can be achieved, and how soon.

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