1.How to treat the surface of color coated coil after processing?
Some products require surface coating (such as PE protective film) to prevent the coating from being scratched during transportation or processing; or embossing or printing (such as wood grain or stone grain) to enhance decorativeness.
2.How to detect the surface quality of color-coated galvanized coils?
Online testing: Coating uniformity and performance standards are ensured using equipment such as a coating thickness gauge (to measure dry film thickness), a gloss meter (to measure gloss), and a colorimeter (to measure color deviation).
Offline sampling: Samples are collected for adhesion testing (cross-cut method), impact resistance testing, and salt spray resistance testing to verify product quality.
3.How to coil and pack color coated coils?
Qualified color-coated coils are reeled onto a winder and slit into specified lengths (such as flat sheets) based on customer needs, or kept in rolls.
Finally, they are packaged (wrapped with waterproof film and covered with anti-rust paper), labeled with specifications, material, color, and other information, and then stored for shipment.
4.What are the core process points of color coated coils?
Coating uniformity: This relies on precise control of roller pressure, coating viscosity, and substrate speed to avoid defects such as coating skips, streaks, and pinholes.
Curing temperature profile: This must strictly adhere to the coating manufacturer's specifications. Excessively high temperatures may cause coating degradation and discoloration; insufficient temperatures may result in incomplete curing, affecting weather resistance.
Environmental requirements: The use of chromium-free passivation and low-VOC (volatile organic compound) coatings is an industry trend to reduce environmental pollution.
5.How to perform high temperature curing on color coated coils?
Entering the curing oven, the temperature and curing time are controlled according to the coating type:
PE, SMP: Curing temperature 180-220°C, curing time 30-60 seconds.
HDP, PVDF: Curing temperature 220-250°C, curing time 60-90 seconds (high temperature ensures full cross-linking of the fluorocarbon resin, improving weather resistance).
During the curing process, the solvent in the coating evaporates, and the resin undergoes a chemical cross-linking reaction, forming a hard, continuous coating.