Camelback Comércio de Pneus de Santos Ltda.
Machine and software to control vulcanization process for tires
will make company competitive in the world’s 2nd largest market

Evanildo da Silveira

José Pedro Souza, today a partner of Camelback Comércio de Pneus de Santos (Camelback Commerce of Tires of Santos), never dreamed he’d ever own a business – much less a company specialized in tires – when he retired from the Companhia Siderúrgica Paulista (Cosipa), one of Brazil’s largest steel mills. He had been on leave of absence since 1990 because exposition to benzene at work had caused a reduction of white blood cells. He had plenty of energy though: only 40-years old (the early retirement was due to the unhealthy working conditions), Souza wished to find a company that would use his experience in quality control – at Cosipa, where he started in 1975 as an industrial helper, he had also been a metallurgical controller, head of the area of coal quality control and technician in metallurgy and quality. He was hired by a tire retreading company from Santos, Brazil’s main port, on the State of São Paulo coast. “I started as manager, knowing nothing about tires,” he laughs. “But I was familiar with management and operational processes.”

In the new job Souza put into practice his expertise in the area of quality control and, at the same time, studied tires as much as he could. This self-taught formation turned him into an expert capable of identifying the problems in the retreaded tire market and led him to create Camelback in 2002. Modestly headquartered in Souza’s own residence in neighboring Guarujá, the company still involves only four individuals, but is already a client of the Programa Inovação Tecnológica em Pequenas Empresas (Technological Innovation in Small Businesses Program, PIPE), the program of the State of São Paulo’s Research Foundation (Fundação de Amparo à Pesquisa do Estado de São Paulo, Fapesp) that supports small innovating businesses. With a tire retreading machine and a software in development, Camelback is waiting for the result of an edict Fapesp launched together with the venture capital company Imprimatur. If it is approved, Camelback may have Imprimatur as a partner.

Vulcanization: the most important stage of tire manufacturing

To understand what the innovations in Camelback’s products are it is necessary to know a few things about tire manufacturing. In this industry, the most important process is vulcanization: it is through it that a polymer known as camelback – thus the company’s name – becomes the raw material for tires. Camelback is made up of natural or synthetic rubber, carbon black (a material resulting from the incomplete burning of petroleum by-products, usually used as a pigment and reinforcement in rubber and plastic products), sulfur, waxes, emollient oils and other ingredients.

According to Eduardo Pinheiro, an engineer at Pirelli’s Quality Department and author of the Master’s thesis “Modelos Numéricos Aplicados à Vulcanização de Pneus” (Numerical Models Applied to Tire Vulcanization), presented at the University of São Paulo’s Polytechnical School (Escola Politécnica da Universidade de São Paulo, Poli-USP), the most commonly used vulcanization process today is the thermo-chemical one. He explains that heating the camelback along with the mix of chemical products makes possible cross links among the composite’s molecules. “With that the polymer, which initially had plastic, low hardness behavior, acquires an elastic, high hardness behavior, and becomes adequate for a number of mechanical applications, such as, for instance, in tires,” he explains.

The vulcanization process, however, has good results only when condition such as time, temperature and pressure are determined with precision. In other words, in order to get it right one needs to take into account the camelback’s composition, the dimension of the object that is going to be manufactured, and what it will be used for. That’s the big problem: no technology available today controls with precision all those variables.

According to chemist José Eugênio Ganade, a Camelback researcher with a 52-year experience in the development of rubber technology – among other jobs he was superintendent of Dunlop do Brasil for 16 years and headed Pirelli’s Technology Center for three —, the vulcanization process used today is empirical. For a temperature X is estimated a vulcanization time Y,” he explains. “Usually that time is two and a half hours, with a rising temperature that may reach 160° C [352° F],” he adds. But since there’s no precise control of temperature and pressure, vulcanization may take place before, or even not be completed in the pre-determined time period. “When that happens, the quality of the final product is bad,” Ganade points out. “In the case of a tire, its resistance to wearing is impaired, and therefore its durability is shorter.”

Camelback is born

Camelback’s owner learned of the limitations of the vulcanization process as soon as he started at the Santos’ tire retreading company. The first problem he had to face was that 30 percent of the company’s retreaded tires were defective – an extremely high proportion. “We made a list of possible causes and solved them one by one,” he recalls. “The only problem we were unable to solve was the temperature [of vulcanization].”

After a time at the tire retreading company Souza decided to quit and start his own enterprise at the Incubadora de Empresas de Santos (Santos Business Incubator). First he developed a project for the environmentally correct destination of used tires. “It was a big project and for that reason it was not adequate for the incubator,” he says. “The incubating center’s very directors suggested a project in the area of vulcanization. After thinking for days I had the idea of improving the vulcanization process for the tire retreading industry.” His plan to build a machine capable of retreading up to ten tires simultaneously was approved by the incubator’s board, and Camelback was created.

Looking for PIPE

In order to carry on the project the new company would have to get a loan. Souza turned to PIPE, but realized that Fapesp wouldn’t approve a project just for the machine. “I needed something more scientific, involving research and innovation,” he recalls. “From my experience with retreaded tires I knew there was no way to control the vulcanization except with the time pre-determined by the camelback manufacturer. Since that was no guarantee of quality, I searched in the literature the means to control that mechanism – the so-called vulcanization curve.”

In his research Souza found theoretical studies dealing with the behavior of vulcanization – among them Eduardo Pinheiro’s Master’s thesis. But he argues that the starting point for his comprehension of the process was his work in Cosipa with metallurgical coal, a mineral formed by forests buried millions of years ago. “It’s similar to rubber. It too is comprised of carbon molecules,” he points out.

For that reason the behavior of the rubber’s vulcanization curve is similar to the curve of the process of turning coal into coke – coqueificação in Portuguese— so it can be used in the blast furnaces of steel mills.

In a trade show for the rubber industry Souza met Ganade and told him about his experience at Cosipa. “We began to talk and right there we decided that we’d work together in the project,” remembers Souza. “Later we became partners.” Two other people work at Camelback today: a person with degrees in Management and Foreign Trade who is also a laboratory technician, and a trainee.

In 2003, Souza and Ganade submitted to Fapesp the project for the development of the tire retreading machine and the software to control with precision the rubber’s vulcanization process – equipment that may or may not work together. The project was approved in September of 2004, began in 2005 and is expected to end by November of 2008. Fapesp granted Camelback a total of approximately US$ 230,000. “With that money we built laboratory equipment and material,” says Souza. “It also paid for the development of prototypes of the tire retreading machine and the software.” Like other owners of innovating small businesses that PIPE has benefited, Souza says that the program’s support was essential. “Without PIPE’s money there would be no project.”

The software

The software the company has been developing indicates the moment in which the camelback reaches the so-called curing point – that it, when it is vulcanized. “That’s our project’s big innovation: a product that controls the exact vulcanization point, preventing the material from being removed from the mold too soon or too late,” explains Souza. “Independently of the vulcanization’s formulation and acceleration, the software absorbs all the interferences that occur in the process, such as temperature and pressure variations, for instance.”

To find the curing point, Ganade spent two years observing what took place during the vulcanization process at various temperatures. At last he came up with a formula that involves complex mathematical calculations and determines the exact moment that vulcanization occurs for any composite. Once data about the temperature reach the program through sensors in the mold where the polymer is placed it starts to monitor the speed and the progress of vulcanization. So the software “knows” exactly when the process is completed and turns off the equipment. Another advantage is that it can be applied in the manufacture of any product that uses “vulcanizable” rubber as raw material, such as auto parts, footwear and belts. Its launching will take place at the 8th International Convention of Tires and Equipment, or Recaufair Pneushow 2008, to be held in São Paulo between May 5 and 8, 2008.

The machine

Camelback’s tire retreading machine is a hollow steel box 4.10 meters (13.5 ft) long, 1.80 meters (5.9 ft) wide and 2.33 meters (7.6 ft) high. At the top it has a track with braces to keep side by side the tires that are going to be pressed. It also has a hydraulic set to move the press, inside which vulcanization takes place, and a steam and compressed air feeding system that provides the heat and pressure necessary for the process. “The tires placed side by side form a single pressure chamber with control of the vulcanization curve, stable throughout the process, which ensures the uniformity of the product,” explains Souza. “The machine is automated and requires no adaptations in the facilities that already exist in the companies that work in the tire retreading business. Besides, it uses less space. Currently tires are retreaded individually, placed horizontally side by side.”

The president of the Brazilian Association of the Tire Retreading Industry (Associação Brasileira do Segmento de Reforma de Pneus, ABR), Orfilo Henrique Pena, says he’s never heard of Camelback or its products, but believes that, in principle, they may interest companies in the industry. “Currently the vulcanization system through heat, which uses camelback as raw material, requires one mold for each tire,” he explains. “That’s the same system used in the vulcanization and manufacture of new tires. But there is another method, in which no heat is required, that vulcanizes several tires simultaneously through an autoclave.”

According to Pena, Brazil is the world’s second largest market for retreaded tires, – the largest is the United States –, with yearly revenues of more than US$ 2.2 billion. The country has 1,557 retreaders and 18 raw material suppliers (15 domestic and three multinationals), which generate 205,000 jobs, 45,000 of them direct. Each year they put out 8.5 million retreaded tires for buses and trucks; 8 million tires for automobiles; 1 million tires for motorcycles; and 240,000 tires for off-road and agricultural vehicles. “Tire retreading is a worldwide practice born out of the need to avoid waste,” he argues. “Each retreaded tire uses only 25 percent of the material required to manufacture a new one, and has the same durability.”

Camelback hasn’t set a date to put its machine in the market. The company has produced a prototype, but doesn’t have the capacity to produce it in large scale. For that reason, launching will depend on the negotiations already under way with a company that is interested in manufacturing it.

Future

Souza got his Bachelor’s Degree in Environmental Technology and Stewardship at Santos’ Monte Serrat University (Unimonte) in 2006. His house is the company’s headquarters. The laboratory, where research is conducted, is also there. “In addition, we have a partner company in Santos where we carry out the industrial experiments of the process,” he tells. “We also have a lot in Guarujá where we intend to build a plant.” Despite the difficulties and limitations he is optimistic. “Our plan is to launch the product in shows such as Recaufair and begin sales,” he says, referring to the software. “We expect to expand at least 20 percent a year in the next five years.”