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1-1-1 CHEMICAL TREATMENT
Profiles RHF is a company proud of its environmental awareness.
At profiles RHF we have take great care to ensure that the processes in use in our operations are environmentally friendly.
In line with our philosophy to protect the environment, we have chosen to use the most technologically advanced paint system available on the market today, coil coating.
The results produced by using coil coating are second to none. It has excellent adhesive qualities, is highly resistant to corrosion and produces an outstanding finish.
1-1-2 THE TWO COAT SYSTEM
Firstly, a coat of primer, with a thickness in excess of five microns is applied to a strip of rolled aluminium. This coat may be epoxy or acrylic paint, or polyester based resin.
Secondly, a coat of paint, either a pvf2 or polyester based resin, with a thickness in excess of twenty microns is applied.
During the application of the second coat, a chemical reaction takes place in the curing cycle. These reaction bonds the two coats of paint together, and are what provides the excellent anti-corrosion and adhesive properties.
The two-coat system gives the finished product a superb finish and extended life span. The paint finish is durable and provides a high resistance to attack from chemicals.
1-1-3 THE SINGLE COAT SYSTEM
The single coat system does not use a primer.
A single coat of paint, either pvf2 or polyester based resin, with a thickness in excess of twenty microns is applied to the strip of aluminium but with an exception of a slight reduction in life span.
1-1-4 BACK COAT
Back coating is used to give a decorative finish to the reverse side of a strip of aluminium, and to improve the anti-corrosion properties of the standard mill finish. This is usually applied with a thickness in the range of eight to ten microns.
1-1-5 STRIPPABLE FILM
A removable film can be supplied to protect the decorative side of the finished aluminium strip following painting. This film comes in different colors, thickness and grades.
This protective film helps to retain the finish of the aluminium strip if it is to be subjected to rough handling, or roll forming.
Customers should specify the end use of the article to enable the factory to select the most suitable grade of film.
An insight into the continuous coil coating process
The continuous coil coating process begins with the receipt of an aluminium strip in coil form. This coil passes through the continuous coil coating process, to emerge at the end once again as a coil of aluminium strip.
The first stage of the process is for the aluminium coil to be placed on the de-coiler to be unwound. It then passes through a series of rollers called the entry accumulator.
The entry accumulator has a facility, which permits two separate coils of aluminium to be joined together. This can be carried out without stopping the operation of the line, hence the continuous process.
After passing through the accumulator, the strip of aluminium is tensioned to ensure that it maintains the correct level throughout the process. There is a tension level for each grade, thickness and size of aluminium strip. The aluminium strip is then subjected to four separate
Pre-treatment stages.
The first of these stages is degreasing
During degreasing, the aluminium strip is thoroughly blasted on all sides, through a series of precisely located nozzles, by an alkaline solution which is heated to 70§c. This removes any dirt or oil and the aluminium strip emerges free of any contaminants. Rubber rollers are used to squeeze off any excess solution, which is drained back into the degreaser reservoir.
The next stage is to rinse the strip in fresh hot water at a temperate of 60§c. Once again a system of precisely located nozzles blast the strip with the hot water.
The third stage of pre-treatment involves blasting the strip with a mild solution of acid to neutralize any carry over of water. This stage also produces a slight etching effect on the aluminium, which enhances adhesion in the next stage.
In the final pretreatment stage, the aluminium strip is coated with a solution of ambient chrome, which is no minute, that it can only be substantiated with a spectrometer.
Now the aluminium strip has been cleaned and is ready for painting, it enters the paint application unit.
The aluminium strip passes through a series of different stainless steel and rubber rollers which apply paint to it in predetermined colors and thickness.' paint can be applied to part or all of the aluminium strip, the top side, the edges and the reverse side.
The accuracy of the paint application process is such that paint film accuracy of +/- 1 micron can be achieved.
The painted aluminium strip now enters the curing oven. It is important that the paint is cured slowly, and so the temperature zones through which the aluminium strip passes, are raised slowly. The final stage of the curing process will see the aluminium strip heated to a temperature of 241§c. Throughout the process, the temperature is continuously monitored by infra red sensors, and is inter-connected to the main drive system. This ensures that the aluminium strip is heated to the correct temperature, and that this temperature is maintained throughout the duration of the aluminium strip's curing period.
Following the curing process, the aluminium strip has to be cooled. This is carried out in two stages. In the first stage, it is blasted with cool air, and in the second it is sprayed with cold water to complete the cooling process.
The main line drive unit for the whole process will have been set to operate at a pre-determined speed depending upon the width of the strip, its gauge and the particular paint system being used on that aluminium strip.
The aluminium strip now enters its final stage, which is the exit accumulator. Here the aluminium strip is rewound into a coil at a precise and constant tension for dispatch to the customer.
1-1-6 SIXTEEN GOOD REASONS TO USE COIL COATING
Or
SIXTEEN WAYS IN WHICH COIL COATING
IS SUPERIOR TO OTHER PAINT ALLICATION METHODS
FOR APPLYING PAINT TO COILED ALUMINIUM STRIPS
1 coil coating is environmentally friendly.
2 coil coating is cost effective.
3 coil coating gives a uniformity of paint thickness.
4 coil coating gives a superb automotive type finish.
5 coil coating offers outstanding adhesion properties.
6 coil coating is durable and long lasting.
7 coil coating is easy to use for forming and fabricating
8 coil coating can be carried out in a wide range of colors
9 coil coating uses numerous different paint systems
10 coil coating ensures the proper coating of edges
11 coil coating provides superior resistance to corrosion
12 coil coating is an efficient process with no wastage
13 coil coating consumes less energy than conventional processes
14 coil coating offers easy recycling of process materials.
15 coil coating gives a continuity of colour.
16 coil coating is a practical and efficient system.
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