The coil coating process is similar to the giant presses that print every evening. The entire process is non-stop, always running at a fixed speed, and the coil metal is continuously joined so that the length of the coil is virtually infinite. However, unlike printed newspapers, metal coils need to be cleaned, treated, painted and dried to complete the entire process.
All coil coating lines, from the oldest to the newest, have some fixed processes. For example, unwinding, cleaning, processing, painting, curing, and rewinding of packages for transport to the following web, shearing, and assembly processes. In addition to the obvious advantages of high efficiency, environmental protection, and energy conservation, the coil material itself is more durable than a part of the processed product. The basic principle of processing is that the coil material must pass through various processes at a steady speed, and cannot stop or change the speed. Therefore, this material has particularly stable characteristics.
1. Cleaning and pretreatment process
2. Primer coating
3. Topcoat coating
4. Lamination, ginning
5. Roll up again, packaging and transportation
A. Raw material unwinding
B. Coil bonding
C. Stacking feed
D. Metal degreasing, cleaning, rinsing, chemical treatment
E. Drying oven
F. Primer, single or double sided
G. Curing oven
H. Coating unit - topcoat, single or double sided
I. Curing oven
J. Single or double-sided adhesive lamination, embossing
K. Stacking receipts
L. Finished product winding
To achieve the basic principles of coil coating, it is necessary to add a buffer stack at the feed and discharge ports. The stack feeder allows the operator time to stop feeding and join the two coils while the processed coil continues to run on the production line, independent of the processing steps at the feed. Point C in the figure above shows a typical vertical stacker. When the feed end is stopped, the stack feeder continues to feed the coating line and the buffers at the upper and lower ends are gradually brought closer together. However, after the combination process is completed at point B, the feed end is restarted, the stack feeder is gradually separated, and the entire production line is restored to a normal stable state again. This ability to continuously engage the web without stopping the machine causes the length of the web to actually become infinitely long. This process continues until the last roll of material has been processed.
The stacking and discharging machine at the outlet is opposite to the stacked feeder of the inlet. When the feed port stops feeding, the stack feeder feeds the production line. Similarly, the stack discharge machine can absorb the coil of the production line, so that the discharge port can be temporarily stopped without affecting the entire production line. At this point, the upper and lower buffers are gradually removed to buffer more material until the operator at the discharge port removes the finished coil and is ready to wind another bundle at the discharge opening.
The stack feeder can be vertical or horizontal. It can be driven by long hydraulic cylinders or mechanical winches. Some feed mechanisms can hold 650 feet of material, and other typical stacked feeders can typically hold 100 feet. The length is primarily determined by the speed of the coil line, as well as the time the operator feeds and joins the web.
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