Direct relationships exist between the adhesion of water transfer sticker processing and several major factors, such as the base oil of the water sticker, the baking time and temperature after the water sticker is applied, the material of the item being transferred, and the components of the spray or electro-coating on the sprayed parts. Common issues include:

(1) Lack of adhesion, it peels off with a simple scrape, which may be due to the base oil not being compatible with the material of the item being bonded (e.g., PP, PE materials require special base oils), and the incompatibility with the chemical components like spray paint, electroplating, etc., on the item. This incompatibility leads to a lack of adhesion after the two components react.

(2) The adhesion is present but not strong, typically manifested as when scraping with your hand, the material does not come off in one piece but instead, some parts fall off in a powdery form. This situation is mainly due to insufficient baking time or temperature after applying the water paper (e.g., for PP material, after applying, it should be baked at 100-120 degrees Celsius for 30 minutes; if the time or temperature is below this, the adhesion will be insufficient).

During the 100% inspection, the surface varnish may fall off, but the pattern colors remain, appearing dull. This situation is caused by insufficient adhesion between the surface varnish on the watermarked paper and the printed pattern, as well as the sticker not being fully dried.

(4) Insufficient adhesion may also be related to certain operational details, such as the cleanliness of the workpiece surface and the formation of bubbles after the water paper is properly applied.