Linetec's Powder Coat 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 phospate 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 200-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 - Powder CoatIn the electrostatic powder spray system operation, powder is siphoned, or pumped, from a feeder unit through a powder feed hose to the spray guns(s). Linetec has two automated powder coat spray booths positioned in lie for quick color change and special applications. Our rotary guns serve as our primary paint applicators as they allow us to provide the best flexibility, efficiency, and quality possible.
The electrostatic powder spray guns direct the flow of powder; control the pattern size, shape and density of the spray as it's released from the gun; charge the powder being sprayed and control the deposition rate and location of powder on the part. Spray guns can be either manual or automatic.
This electrostatic process encourages the powder to wrap around the part or deposit on the surfaces of the part that are not directly in the path of the gun.
Located after our primary guns, are manual hand spray guns. This 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 charges paint particles to the nearest surface). This gives our customer the best quality possible.
Linetec can provide you with powder coating finishes from almost any supplier, including: PPG Duranar, TCI Powder Coating, Sherwin Williams, Spraylat, Rohm & Hass, Akzo-Nobel Interpon, and Tiger Drylac.
Curing - Liquid PaintAfter emerging from the powder 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 allow 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.