Pendant le processus de construction du revêtement, les opérateurs rencontrent souvent divers défauts de revêtement, ce qui peut affecter la qualité et l’apparence du revêtement, et même affecter la durée de vie du produit. Cet article présentera plusieurs défauts de revêtement courants dans la construction des revêtements., y compris la différence de couleur, dur ou piquant, perte de film, épaisseur de revêtement inégale, etc., et proposer des solutions correspondantes.
1. Différence de couleur
The reason:
La peinture elle-même présente une grande différence de couleur, et la variété de peinture doit être remplacée.
Improper control of film thickness leads to coating color difference, and it is necessary to adjust the film thickness in time.
Improper control of PMT (curing temperature of coatings) leads to coating color difference, and the furnace temperature needs to be adjusted.
Improper control of baking time and air speed in the furnace will also cause coating color difference, and the production process parameters need to be adjusted.
The solution:
Timely change of paint varieties.
Adjust film thickness and furnace temperature to eliminate color difference.
Adjust the control according to the PMT adjustment range provided by the paint manufacturer.
Adjust the production process speed and the balance of air flow in and out of the furnace.
2. Clumps or pitting
The reason:
The substrate is rough or defective, and the substrate needs to be replaced.
Before coating, the coating surface is affected by pollution, and the coating needs to be replaced or filtered in time.
During painting, the air inside the coating machine is dirty and pollutes the coating surface, and the air inside the coating machine needs to be purified.
The acid gas in the furnace is too heavy to cause the paint to harden, so the furnace temperature needs to be adjusted.
The air in the furnace dirty pollution coating surface caused pitting, need to shut down to clean the air in the furnace.
The cooling water is too dirty, contaminating the coating surface during the cooling process, and clean cooling water needs to be replaced.
The solution:
Replace the substrate.
Replace or filter paint in time.
Purify the air inside the coating machine.
Adjust the furnace temperature.
Stop the machine to clean the air in the furnace.
Replace the clean cooling water.
3. Loss of film
The reason:
The improper control of PMT leads to the loss of coating film, and the furnace temperature needs to be adjusted.
Roll speed ratio does not match, need to adjust the roll speed ratio.
The coating roll is defective and needs to be replaced.
Improper viscosity of the coating causes the coating to lose film, and the coating viscosity needs to be adjusted.
The solution:
Adjust the furnace temperature.
Adjust roll speed ratio.
Replace the coating roller in good condition.
Adjust the viscosity of the paint.
4. Uneven coating thickness
The reason:
Roll speed ratio does not match, need to adjust the roll speed ratio.
The coating roll is defective and needs to be replaced.
The solution:
Adjust roll speed ratio.
Replace the coating roller.
5. Horizontal stripes are found on the wet coating surface, C'est, “forehead stripes”.
The reason:
Transverse strip strip of galvanized substrate.
Roll speed ratio does not match, need to adjust the roll speed ratio.
The solution:
Replace the substrate.
Adjust roll speed ratio.
In the coating construction, the operator should always pay attention to the quality of the coating, find and solve various coating defects in time to ensure the quality and stability of the coating, so as to improve the quality of the product and market competitiveness.