What is Preservation Line?
Preservation line is the processing technology that blasting steel plate or beam surface treatment and painting protection antirust paint before processing. After preservation can improve the corrosion resistance of mechanical products and metal components, improve fatigue resistance, extending its life; It also can optimize the production process state of steel surface, in favor of CNC cutting machine to cutting and precision blanking. Furthermore, since the workpiece before processing is regular shape, it is conducive to mechanical descaling and automated spray paint, so using preservation can reduce labor intensity and greatly improve the efficiency of clean-up operations, reducing pollution of the environment. Sheet widths of up to 5000mm can be processed, with passage speeds varying from 1.0m/min to 8.0m/min.
Preservation lines consist of pre-heating, shot blasting, painting and drying functions in one complete production line, can coat the work-pieces with a temporary painting which can last several weeks to protect the surface before final coating.
Main parts of Preservation Line
Part Name
1.Inlet roller conveyor
2.Shot blasting machine
3. Dust collector
4. Paint spray chamber
5. Paint mist process system
6. Drying chamber
7. Outlet roller conveyor
Optional
- Cross transfer conveyor (loading system)
- Pre-heater
- Cross transfer conveyor (unloading system)
Working Principle
The steel enters the shot blasting chamber from the roller conveyor system, and the abrasive (steel shot or cut wire shot) is accelerated and projected to the surface of the steel by the blast turbines, and the surface of the steel is impacted and scraped to remove rust and dirt on the surface of the steel; then blow away the abrasive and floating dust on the surface of the steel with a brush, a screw conveyor and a high-pressure fan; the steel after derusting enters the painting booth, and sprays the maintenance primer on the steel surface through the spray gun installed on the upper and lower painting cars , unload the workpiece from the output roller conveyor. So that the steel can achieve the purpose of rust removal and rust prevention.
The whole process achieves the purpose of rust removal, rust prevention and surface strengthening.
Working Video of Preservation Line
Key Features of Preservation Line
Roller conveyor system
QGMA offers various kinds of transport options for customers from different industries, roller conveyor system including rollers, chain, reducer, sprocket cover, and roller support.
A roller is first welding and then processing, to ensure the concentricity of the roller, running speed range 0-6 m/min with speed converter, material of roller is 45# carbon steel.
Load capacity from 1t/ M-5T /m.
Cross conveyor for load and unload to higher efficiency, slat conveyor with spot contact instead of face contact for wet work-pieces after painting process.
Shot blasting system
QGMA has designed high performance shot blasting machines which can be integrated into preservation lines for any industry.
High performance blast wheel adopts an abrasive dynamic design, which allows all abrasive leave the turbine when they reach the highest speed with the least internal bounce and self-wear. Also use high resistance liners made from high chrome cast steel, the abrasive hot zone has a maximum thickness up to 70 mm.
Blast chamber used ZGMn13 steel guard, which is hard enough to deal with the shot blasting from 35HRC to more than 55HRC.
Mature abrasive circulation system can ensure the normal operation of the whole machine. The dust collector system is indispensable to ensure that the whole machine meets the local environmental requirements.
Abrasive cleaning up system can clear the abrasive on the surface of the workpiece to meet the painting standard.
Painting System
- Automatic spray room is composed of frequency converter, motor, drive chain, traction chain, paint car, chamber, towline and high-pressure airless spraying machine etc. The traction mode is driven by motor directly, and the painting car continuously make reciprocating movement no matter the painting car spray painting or not.
- Painting chamber is the most important parts of this line, it achieve automatic paint for steel plate. The painting chamber has two models: automatic and manual.
- As there is often a lengthy manufacturing or storage time between blasting and final coating, the workpieces are painted with a quick-drying, temporary anti-corrosion coating in the spray chamber in an airless spraying process (coating thickness approx. 15 – 25μm).
- Airless painting, automatic direction switching unit instead of changing running direction of motor, linear track with low resistance, painting nozzle & gun separately layout to prevent painting gun pollution, exhaust air 3-level treatment (cotton filter, activated carbon and UV).
Drying chamber
- The drying room adopts the principle of hot air circulation drying. After the steel is dried in the drying room, the surface paint film can reach the finger dry state. We can control the number of power module groups to save energy.
- The chamber body is made of double-layer sheet box structure, lined with thermal insulation material, which is conducive to the full utilization of heat. The side wall adopts the open-door structure to facilitate the maintenance of the plate chain system.
- The conveying system in the drying room adopts slat-conveyor. The slat- conveyor adopts a unique four-line support structure to effectively solve the problem of deviation during the operation.
- Slat-conveyor adopts long pitch roller chain, so that the load of the steel plate is evenly distributed on the conveyor, which is different from the old driving method in the past, and completely rid of the problem of bearing damage.
Auto Loading and Unloading system
- Automatic loading and unloading is also called hydraulic cross transfer system. Through the loading system, the workpiece can be transferred to the inlet roller conveyor. Through the loading system, the workpiece can be unloaded from the outlet roller conveyor.
- Loading and unloading system are respectively composed of lifting trolley, heavy support, traction mechanism and hydraulic system, and workpiece carrying is completed by lifting trolley. The lifting of the trolley is realized by the hydraulic cylinder, and the cross transfer movement is realized by the chain transmission mechanism.
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