JPH0315497B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an electrostatic coating method for resin molded articles.

[Prior Art] Paints for painting resin molded products are more expensive than paints for painting steel plates, and primer paints are especially expensive. Therefore, when painting resin molded products, it is necessary to further improve the coating efficiency.

[Problems to be Solved by the Invention] However, when a resin molded product is electrostatically coated, an improvement in coating efficiency cannot be expected because the object to be coated is a resin.

An object of the present invention is to improve the coating efficiency when electrostatically coating a resin molded product and to reduce the amount of expensive resin coating paint used.

[Means for Solving the Problems] That is, the present invention provides a method for electrostatically coating a thin resin molded product with a primer paint and a top coat, by applying a plate-like material made of a conductive material to the surface opposite to the painted surface. A mounting jig made of An electrostatic coating for a resin molded product characterized by electrostatically coating a conductive plummer paint as a paint, then electrostatically coating a top coat, and using the mounting jig as a tool to prevent thermal deformation during coating baking. Regarding electric coating method.

[Embodiment] Next, the present invention will be explained based on the drawings.

FIG. 1 is a schematic cross-sectional view showing a state in which a resin molded product is attached when the resin molded product is electrostatically coated in an embodiment of the method of the present invention.

Reference numeral 1 indicates a thin resin molded product, such as a bumper cover for an automobile. The bumper cover 1 is attached via an attachment jig 2 to a hanger 3 running on a conveyor. The mounting jig 2 is a plate-like object 4 made of conductive material.
and a connecting member 5. The plate-like object 4 has a shape that almost follows the entire back surface of the bumper cover 1, which has a substantially U-shaped cross section, and is made of aluminum,
It is made from a highly conductive material such as copper. The plate-like material 4 may be a normal plate material, a material with holes punched therein, or a net-like material. The connecting member 5 is not particularly limited as long as it has conductivity and can attach the plate-like object 4 to the hanger 3.

The bumper cover 1 is attached to the hanger 3 via the mounting jig 2, and the plate-like object 4 is set to have a different polarity from the paint gun (not shown) (for example, if the paint gun is used as the negative electrode, the plate-like object 4 is connected to the conveyor). When electrostatically paints in this state (paint particles fly in the direction of the arrow), an electric field is formed between the paint gun and the plate-like object 4 so that the paint particles collide with the painted surface. This improves the coating efficiency.

The method of the present invention is suitably applied to resin molded products having a plate thickness of about 4 to 5 mm, and the coating efficiency can be improved.

In the present invention, the coating efficiency is improved by simply improving the mounting jig for the resin molded product during electrostatic coating.

Further, in the present invention, the mounting jig 2 can be used to prevent thermal deformation of a resin molded product during paint baking. For this purpose, it is desirable to have the plate-like object 4 completely along the back surface of the resin molded product, but this is difficult when the shape is complex like the bumper cover 1. In such a case, the plate-like object 4 should be replaced with the bumper cover 1.
The bumper cover 1 may have a shape that roughly follows the back surface of the bumper cover 1, and a filler 6 may be appropriately interposed in the gap between the plate-like object 4 and the bumper cover 1. The filler 6 may be made of resin or metal such as aluminum. The filler 6 may be fixed to the plate-like material 4 by an appropriate means such as adhesion.

Furthermore, in the present invention, when a resin molded product is electrostatically coated with a primer paint and then electrostatically coated with a top coat, the coating efficiency of the top coat is improved by using a conductive primer paint. This can be further improved.

In other words, when applying electrostatically conductive primer paint, the application efficiency of the primer paint is improved by using the improved mounting jig described above, but when applying electrostatically conductive primer paint, the painting surface Since a conductive primer layer is formed on the base plate, the presence of the conductive primer layer and the use of the improved mounting jig further improve the coating efficiency of the top coat.

As the conductive primer paint, a material obtained by adding metal powder such as aluminum powder to a normal primer paint for resin coating is used.

In the present invention, by using the above-mentioned improved mounting jig, the paint application efficiency can be increased to about 50%, but in addition, since a conductive primer paint is used, it is possible to increase the paint application efficiency by approximately 50%. Efficiency can be increased to around 80%.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a state in which a resin molded product is attached when the resin molded product is electrostatically coated by the method of the present invention. Main symbols in the drawing: 1: resin molded product, 2: mounting jig, 3: hanger, 4: conductive plate-like object.

Claims (1)

[Claims] 1. When electrostatically painting a thin resin molded product with primer paint and top coat, a mounting jig made of a plate of conductive material is placed along almost the entire surface of the surface opposite to the painted surface. However, the mounting jig is used consistently from primer painting to baking the top coat, and the mounting jig is different from the paint gun.
A resin molded product characterized by electrostatically coating a conductive primer paint as a primer paint, then electrostatically painting a top coat, and using the mounting jig as a device to prevent heat deformation during baking of the paint film. Electrostatic painting method.