Prevention and control of common defects in summer paint construction

China Paint Network
News: excellent coating appearance needs stable process technical support, process parameters changes will directly affect the quality of the body, the summer high temperature production of body quality problems are a major problem that plagues many manufacturers at present, how to produce good products in the transition phase of process parameters changes, the need for the summer high temperature season appeared in advance of various quality problems prevention and control, the following is the summer prone to quality problems in all aspects of insight and control methods.
1.Summer
Paint
Construction Common Defect Prevention and Control
1.1 Orange Peel
definition: the surface of the coating film presents more than 1mm orange-like ripples called orange peel.
causes:
1) the viscosity of
coating
is high, the leveling agent or solvent used in the coating film is improperPoor paint atomization caused by small amount of spitting or low spray pressure,
4) body spray room temperature is higher in spraying, paint leveling agent is not according to the change of spray room temperature increase slow drying agent, resulting in the paint solvent volatile faster,
5) paint drying time is shorter.
Precautions:
1) in the summer high temperature spraying process, according to the temperature changes in the spray room to appropriately reduce the paint viscosity or increase the paint in the high boiling point solvent;
2) adjust the spray gun distance, generally requires the spray gun and the coating distance of 20 to 30 cm, and appropriately increase the thickness of the paint coating film.
3) Paint pressure is controlled between 0.4 and 0.6MPa, and the automatic spray parameters and manual spray gun are adjusted to optimal condition;
4) the general drying time is controlled at 5 to 10min;
5) substrate polishing leveling.
Remedy:
1) after spraying timely check the body coating film condition, found that the coating film appears orange peel, the site using temporary artificial paint, and reported to the process personnel to adjust the process parameters
;
1.2 pinhole
definition: paint body spray paint film in the drying process, the paint film surface has been dried into shape, but the film interior due to solvent continues to volatilization, through the initial dry paint film surface formed by the pinhole or like a leather pore-like small hole called a pinhole.
causes:
1) spray room temperature is higher, sprayed coating surface drying fasterThe leveling agent and solvent selected in the coating are improper


Precautions:
1) observe the dry and wet condition of the coating film after spraying, appropriately increase the leveling agent,
2) adjust the drying temperature according to the process requirements, require the drying oven heating curve to rise steadily,
3) select a suitable leveling agent or Solvents;
4) body substrate according to the requirements for polishing, spray paint and then spray paint,
5) strengthen the paint purchase inspection, paint deployment, recycling, use of the process of attention to paint can not contain moisture.
remedy: the use of wet or dry round grinding method to eliminate the primer surface pinholes and then re-sprayed in the paint, dry paint body can be polished polishing.
1.3 flow hanging, sinking, flowing
definition: the coating surface there is too much coating in the vertical surface and edge of the coating cured and firmly attached to the phenomenon called "flow hanging", coating finished to dry during the coating local drooping, uneven thickness of the semi-circular, ripples and other phenomena called "sinking", the coating surface coating large area of the phenomenon known as "flow".
Causes:
1) spray gun and coating distance is too close, spray gun movement speed is too slow, one-time spray too thickPoint solvent content is many, paint sticky through the low,
4) spray room wind speed is not within the scope of the process, ambient temperature is too low,
5) wet wet spray drying time is short,
6) spray uneven, coating thick at the table dry slow, such as its lower thin easily form a flow hanging.
Precautions:
1) in strict accordance with the process requirements for spraying, for the higher requirements of the coating film can be divided into multiple sprays, each spray needs to be dried and then the next spray
ing
Check that the viscosity and spray pressure of the coating are within the normal process range,
4) increase the temperature of the paint room within the required range, measure the wind speed to ensure that the wind speed meets the requirements,
5) select the correct thinner,
6) ensure that the surface is clean when spraying.
Remedy: After drying the coating film, wet sanding and polishing the conve current hanging with fine sandpaper, scraping with a scraper at a larger area of the conve current hanging, then polishing the conve current hanging place to no flow marks and re-spraying drying.
1.4 chroma
definition: the body after spraying or after measurement with a chroma meter, there is a difference between the phase, brightness, purity and standard schrome.
causes:
1) there are differences between the batch of paint,
2) spray gun cleaning is not clean to appear mixed or cross-color,
3) primer and finish improper matching, drying has been baking phenomenon.
Precautions:
1) strengthen the paint into the factory inspection, paint chroma test strictly in accordance with the company's standards,
2) the implementation of process inspection, strictly in accordance with the operating instructions to operate,
3) according to the requirements to optimize the paint colors and the matching relationship between the medium coating, color difference after no problem curing.
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