Linetec's Paint Process
Linetec utilizes advanced equipment and techniques in all of our facilities: paint, powder coating and anodize. This overview describes the finishing lines available to meet your quality and service requirements. Our facilities have a thorough tracking system that allows us to monitor the progress of your individual order through every step of order entry, receiving, processing and packaging, assuring that every order receives high visibility and individualized attention.Your products are racked horizontally on a 960-foot long overhead conveyor that travels up to 24 feet per minute. Material falling within the on-line parameters can be finished on-line. Material falling within the off-line parameters is considered Oversize and can be finished off-line. If your material exceeds these limitations, please contact Linetec for a review of your requirements.
Pretreatment - Liquid Paint & Powder CoatingPaint systems are designed to be applied over clean metal that has been properly pretreated. At Linetec you can be assured of the quality of the pretreatment system which, in summary, consists of:
|Stage 1||High temperature acid clean, etch and de-smut|
|Stage 2||Ambient rinse|
|Stage 3||Amorphous chromium phosphate conversion coat|
|Stage 4||Ambient rinse|
|Stage 5||Final rinse with R.O. water|
|Dry Off||Gas Convection Oven|
Unlike batch pretreatment systems that group your products together and immerse them into a static dip tank, Linetec utilizes a dynamic power spray pretreatment system. Your products are racked individually in the staging area and continue through the five stage 130-foot long power washer that cleans and treats them in accordance with AAMA & ASTM specifications.
Stage one of the pretreatment systems incorporates 140 high-pressure nozzles positioned to reach recessed areas on lineal or fabricated parts. Stage one nozzles circulate 550 gallons per minute of high temperature (140-160 degrees Fahrenheit) acidic solution, which cleans, etches and de-smuts the aluminum.
Stage two incorporates a high power clean water rinse.
In the third stage the aluminum surface is converted to an adherent, amorphous, iridescent surface through a chromium phosphate coating which increases the corrosion-resistance, adherence and durability of any applied paint film. This conversion coating is recommended for use under severe conditions of service and for all architectural aluminum finishes.
The fourth and fifth stages of the pretreatment system are neutralizing clean water rinses containing 24 high-pressure clear water rinse nozzles in two columns. R.O. water is used in stage five to remove any hard mineral staining.
The high volume re-circulating system used in the pretreatment chamber provides a high velocity spray on your product creating a scrubbing/flushing action. Solutions are recycled after passing through pretreatment baffles and filtering systems so the pretreatment used on your product is always fresh. The pretreatment tanks are checked and maintained regularly by dedicated chemical technicians to assure that the solutions and temperatures are operating at optimum conditions.
After pretreatment, your horizontally racked product continues around our continuous loop system into a dry off area. Air knives blow the clean water off the aluminum parts, racks, and overhead conveyor chain. From that point, your product moves directly into a dry-off oven where any remaining moisture is evaporated.
Application - Liquid PaintLinetec has five pairs of booths stationed on line. Booths are placed in opposing pairs so that both sides of your product can be painted without physically touching your product. The application equipment in the first booth applies the coating to one side of your product and the application equipment in the second booth applies the finish to the other side.
Our rotary atomization bells (automatic spray equipment) serve as our primary paint application as they provide the best flexibility, efficiency, and consistent quality possible.
The coating is fed to the center of a bell-shaped atomizer that rotates at 10,000 to 60,000 RPM under full coating load. Centrifugal force spreads the coating to the edge of the bell and spins it off in finely atomized electrostatically charged particles. Air jets surrounding the atomizer shape the spray pattern and help direct the charged particles toward the grounded part being coated.
Booths 1 & 2 are used to apply the primer coat, we use the electrostatic rotary atomizing bells. The rotary bells apply a high voltage charge to the coating materials at the point of atomization. This electrostatic charge allows a more efficient, uniform application of coating materials to the front edges, sides and back of your product.
Booths 3 & 4 are used to apply approximately 70% of our total coating. We have three automatic rotary atomization bells in each booth for a total of six bells. Our state-of-the-art systems use horizontal and vertical electric eyes to control each bell’s proximity to your product. This, coupled with the automatic color changes and versa view control panels that control all of the bell operations, provide Linetec the capability to apply the best finish in the industry.
Booths 5 & 6 are manual electrostatic hand spray booths. The location of these booths behind our primary bell booths allow us to paint those areas the automatic equipment cannot reach. Our topcoat painters are skilled craftsmen who, through classroom training and many years of experience, apply a superior finish.
Booth 7 & 8 are electrostatic bell booths configured the same as Booths 3 and 4 to give us the flexibility to paint many different types of profiles and meet the diverse requirements of our customers. Both booths 7 and 8 also have the ability to be used as reinforcing booths for difficult material or hard to cover paints prior to clear coating.
Booths 9 & 10 are manual electrostatic and non-electrostatic hand spray booths. These booths give our applicators the ability to reinforce or “target shoot” those areas that are more difficult to paint because of recesses or areas affected by Faraday Cage (the attraction of charged paint particles to the nearest surface). These booths also are used to apply “clear coat”. Clear coat is used as another protective layer to enhance the endurance and weather resistance of our paints, especially metallic’s and other exotic colors.
Curing - Liquid PaintAfter emerging from the paint coating booths, your product is conveyed through a flash-off area and into our 200-foot long, four-stage gas powered convection oven. For proper cure of 70% fluoropolymer (Kynar 500 or Hylar 5000) finishes the aluminum must reach a peak metal temperature (PMT) of 450 degrees Fahrenheit for at least five minutes. Our oversize oven allows us to run at cooler temperatures and still reach specified metal temperatures and bake times because of the increased “dwell time.”
Heavy tubes and thick walled products must be baked at higher temperatures than thinner material to bring the metal to required temperatures in the allotted time. Oven temperature is monitored with temperature gauges, and heat tapes are placed on your product to assure that PMT was reached. Line speed is also regulated to make sure the necessary amount of dwell time is achieved.
After the paint has cured, material is inspected by our quality assurance team for color, gloss, mil thickness, appearance and multiple other performance specifications.