Following a fire, a virtually New Production line was installed at Reynolds Aluminum in Harderwijk, the Netherlands, for the surface treatment of aluminum sections. Unique in Europe, it was the result of perfect co-operation between Reynolds, the Torsit engineering bureau, Omron, and others.
According to Ron Marree, the Reynolds project engineer, everything went smoothly right from the word go. Vertical processing line controlled with Omron FV regulators After silicon (sand), the reserves of bauxite - the ore from which aluminum is extracted - are the second largest resource in the world. The production of aluminum requires a great deal of energy, but aluminum can be recycled without any loss of quality, using only 5% of the original energy. At the moment, 90% of aluminum building materials are recycled with a comparable amount being recovered from domestic waste. In this respect, this metal is distinguished by its extremely environmentally friendly character. Moreover, it is light, strong and hardwearing. In short, it is an ideal construction material.

Specialist skates

Reynolds Metal Company is one of the world's largest aluminum producers, and has more than a hundred subsidiaries in 22 countries. Reynolds Aluminum Holland is active in two key fields: extrusion and surface treatment. For extrusion, aluminum ingots are passed through a mould under very high pressure (up to 80 kilos per square millimeter), rather like a potato through a chip cutter. The shape of the mould determines the shape of the section; in Harderwijk the client has a choice of about 20,000 different shapes and sizes. Everyone is familiar with the sections for window frames and door frames, but Reynolds Holland also produces runners for skates, and is an important supplier to the car industry. For example, the company in Harderwijk makes bumpers and sections for sunroofs for Audi, Saab, Mercedes and Volkswagen. Ford America was so satisfied with the co-operation with Reynolds Holland that it awarded it a Q1 certificate, the highest quality award in the car industry.

Shorter processing time

A few years ago, it was decided to replace the horizontally-oriented production process by a method in which the sections pass vertically through the various chemical baths. Vertically transported sections dry faster and better, so that fewer chemicals need to be used, and the rinsing water is less polluted. Furthermore, it means that only one suspension point is required, which speeds up the processing time and results in less scrap. However, a vertical installation requires different transport technology and a significantly higher space. In order to treat the more than 7 metre tall sections vertically, it proved necessary to build a hall 26 metres high. This represented an investment of scores of millions, though it led to significant opportunities from the point of view of quality and competition.

Precise control

Vertical transport for anodising and colouring is still fairly unusual. Dick Speek, the team leader in the Reynolds measurement and regulation department said: We opted for the technology of an Italian firm, which was to deliver the system here turnkey. However, the installation did not operate satisfactorily. We developed our own-patented process for colouring sections here. For this purpose, the sections are submerged in a tin bath for a short time. The immersion times are critical: a few seconds shorter or longer leads to differences in quality. Furthermore, the baths are narrow, so the sections may not swing about. In other words, precise control of all the movements - raising, lowering, accelerating and slowing down - is crucial, particularly for longer sections. This control was not as good as it should be in the Italian solution.

Starting at zero

At the beginning of September 1996, fire broke out at Reynolds and the virtually new processing hall was so badly damaged by soot and heat that it had to be rebuilt. It was a total disaster, but also an opportunity to deal with some of the teething problems. However, this was no easy matter. Speek relates: We had hardly any documentation from the old plant. The Italians had delivered everything turnkey, and hardly put anything on paper, so we had to start at the beginning. Reynolds instructed the Torsit firm, specialists in lifting and hoisting technology, to calculate the specifications for the new plant and produce a design. Kees van der Wal, a project leader at Torsit, explains: For the lifting manoeuvre, we opted for one motor instead of two. We replaced the chains with cables, and designed a new hoist. Everything was easier to operate and maintain. In addition, we wanted to be able control the operating speed of the various cranes better. They had to start and stop more smoothly. The sliding armatures from the old plant were replaced with standard short-circuited armature motors. All in all, this meant that we had designed a completely new plant.

Best price/quality

New motors also meant new operation. It was not possible to achieve the required technology with the products of most of Torsit's suppliers, but Omron was able to come up with a solution. By chance, Reynolds had already been introduced to Omron. Ron Marree, who was the project co-ordinator for the new building for Reynolds at the time, states: We found that Omron was one of the suppliers who were able to come up with a solution for us. It offered the best price/quality ratio, and they were also prepared to think about our problems in detail. In the end, Omron supplied 18 flux vector frequency regulators as well as 18 smaller regulators for the shoe adjustment of the nine large cranes.

Eight months

The flux vector regulators were new for Torsit, but this was not a problem in practice. Kees van der Wal explains: Omron provided support for the adjustments, but the regulators have an auto-tuning function, so they are actually self-adjusting. Together with OMRON and Reynolds, we came up with a software solution for lifting equipment safely. In fact, Omron now also delivers this software as a package. According to Ron Marree, the co-operation between the various parties was excellent. After the fire, we built up everything in eight months on the basis of a completely new design. Only the feet of the cranes were not replaced. Nevertheless, everything went perfectly from the very start, which is a compliment to all the parties concerned. At the time, we placed a heavy responsibility on Torsit, but they proved themselves more than equal to the task. We now have the most advanced vertical plant in Europe.