CONTAINER PAINTING OPERATION ESSENTIALS

First, spraying distance

The spraying distance refers to the distance between the front end of the spray gun and the surface of the box, which is generally 30~40cm. The constant spraying distance is an important factor to ensure the uniform and consistent thickness of the coating film -+-,<- gas spraying distance affects the thickness of the coating film and the coating effect. Under the same conditions, "distance close to the thickness of the coating film is high painting efficiency. But the spraying distance is too close in the unit time to form the coating film is too thick, easy to produce "flow hanging", "wrinkle" and other coating diseases. On the contrary, the spraying distance is far and the film thin efficiency is low. If the spraying distance is too far, the coating will fly away and the coating efficiency will be poor. In addition, because the paint fog particles in the atmosphere for a long time, thinner volatilization, resulting in rough paint, even loss of light.

The spray gun must be perpendicular to the surface to be painted. When the spray gun is running around, it should be kept parallel to make the spraying distance constant. If the gun is running in an arc shape, the spray distance is constantly changing, so that there is a significant difference between the middle and the ends of the film.

In addition, the spraying distance is also closely related to the width of the fog. If the running speed of the gun and the paint spray is the most constant, the spraying distance gradually increases from near to far, the result will be that the spraying distance is close to the spray amplitude is small, the film is thick; Spraying distance to large, spray width will be selected as uneven film, even "bare bottom fly

Two, the overlap of spray fog amplitude

Because the spray pattern is thicker in the middle, the edge is thinner. When spraying, the front and rear fog must be bonded to each other in order to make the film uniform. That is, after spraying the first row of fog, the second row of fog should overlap with the first row of fog by 30% ~ 50%. To maintain the box film thickness uniformity. Figure 5-2 shows the overlap of the spray amplitude.

Three, the movement speed of the spray gun

In container spraying process, each coating must reach its specified film thickness; The nozzle selected according to the specified film thickness has its fixed flow and spray amplitude, so the moving speed of the spray gun is the main factor to control the film thickness. The proper running speed should be determined in accordance with the requirements of the film thickness, and kept constant, in order to obtain uniform film thickness. According to the long-term production practice of container technology, the flat operator can master the reasonable movement of spray gun. According to the author's observation, it takes 5~6 minutes to complete each side plate (6m long}, that is to say, the speed of the spray gun moving is I. 0 to 1.2m/min.

Four, the correct arrangement of spray painting sequence

For example, when spraying paint on the outside of refrigerated containers, the time of manual spraying on the front and back cabinets and automatic spraying on the top plate must be arranged at the same time to avoid the production of paint mist particles due to the time difference between the two. Also like the day of hot spray paint, in order to avoid the left and right side of the inner surface rough, the correct procedure is: top plate ~ front plate - left and right side plate. Also, in order to avoid the door frame color confusion, after spraying the inside and outside paint, close the door, and finally spray the outside paint on the door frame.

The outside of the container is the key part of the whole painting operation, but also the owner of the box to check the thickness of the film. In order to avoid leakage or film thickness is not enough than the general spray in the left and right side plate or front plate, first in the upper and lower strip, especially the opposite side of the strip, transverse spray a gun, and then longitudinal spray.