Technology and equipment arrangement of UV roller coating for wooden door
With the development of economy and the improvement of market, people’s consumption concept is changing from material to spiritual level. The design of household products has become the necessary soft power of every enterprise, which is particularly intuitive in the wooden door!
With the ever-changing shape and style of wooden doors, supporting services are provided for different space design. With the change of home style, wooden door design is also developing towards the following trends:
But the design is not only limited to appearance, but also involves many aspects such as function and quality. The market does not just need to be novel and good-looking. Good surface quality is very important. Without this, any of the above trends will be a flowery shelf. That is to say, in order to have a good appearance of wooden doors, the most important thing is to do a good job in surface coating! Among them, UV roller coating is of great concern.
In all the present finishing processes, roller coating plays an important role in the furniture painting. With the improvement of people’s living standard, the requirements for home furnishing and decoration are higher and higher. UV roller coating has an inestimable development prospect in furniture coating, especially in wood door coating, because of its superior performance.
The process and equipment layout of UV roller coating are determined according to the painting requirements and effects. The typical UV roller coating process of wooden door includes “one layer of coloring, two layers of putty, three layers of primer, two layers of finish”, “one layer of coloring, one layer of putty, two layers of primer”, etc. The following is a detailed description of the important process of UV roller coating for wooden doors:
- Plain plate sanding
After the fixed thickness, pressing (veneer) and molding of the door leaf, fine sanding is required before finishing, not only to achieve the surface flatness, but also to achieve the necessary finish. This sanding should ensure that the erected wood fiber is completely removed, and proper fine sanding can ensure satisfactory coloring effect.
- Water based coloring
Equipped with two roller coloring roller coater, the first roller is sponge roller and the second roller is rubber roller. The sponge roller should be pressed about 1mm more than the rubber roller to ensure the color of the chamfered edge. The pressure of the rubber roller is slightly higher than that of the coating roller which is coated with primer, so as to ensure that the spot spots left by the sponge roller can be ground smooth. The coating amount shall be controlled in the range of 10-20g / ㎡, generally determined by the coloring effect and the surface condition of the plate.
- Water based base color drying
After water-based coloring, the panels need to enter the hot air drying tunnel for drying. The drying temperature shall be controlled within a reasonable range. If the temperature is too low, the water in the water-based background color can not be discharged, which will affect the adhesion and clarity. If the temperature is too high, there will be more burrs on the board surface and the board will be deformed. If the water-based UV coating is used, a double lamp UV dryer shall be equipped after the hot air drying tunnel to cure the UV component in the water-based background color.
- Putty curing
A single lamp UV dryer is used for semi curing between the two putties, with a curing energy of 60 ^ 80 MJ / C ㎡. It is better to slightly stick to the hand after cyclization, so as to increase the adhesion of the paint film. After the two putties are filled, they are cured on the surface by double lamp UV dryer, with a curing energy of 100 ^ 120mj / C ㎡, with no stick to the hand and obvious scratches. This is not only convenient for sanding, but also can ensure the adhesion with the next primer Yes.
- Primer coating
The application amount of primer is determined by the overall fullness of the paint film, generally 2-3 layers of primer, each layer is 10-20 g / m2. After the last layer of primer, leveling device can be selected to increase the flatness of the paint surface and reduce the amount of sanding.
- Primer curing
The curing and drying of primer must be well controlled. Over curing will make the coating behind hard to adhere and hard to sand. Generally, single lamp UV dryer is used for curing of primer room, with curing energy of 60 ~ 80mj / C ㎡, and double lamp UV dryer is used after the last primer, with curing energy of 100 ~ 120mj / C ㎡.
- Finish coating
The first finishing coat is used for color modification, with the coating amount of 7-8g / ㎡; the second finishing coat can be applied with laser roller to increase the film fullness. Laser roll coating is generally 18-25 g / m2, after coating, the surface will leave very fine lines, it is these lines that damage the surface tension of the coating film, to ensure that the surface of the substrate is more smooth.
- Drying of finish paint
Generally, UV single lamp dryer is used for semi curing in the finishing coat room, with curing energy of 80-120 MJ / C ㎡; after the last finishing coat, UV three lamp dryer is used for complete curing, with curing energy of 330-400 MJ / C ㎡.
The painting operation of wooden door is the last production process in the manufacturing process of wooden door, and it is also a very important process in the process of wooden door. The painting operation of wooden door is also a very technical operation in the whole manufacturing process of wooden door. The level of painting operation, to a large extent, can reflect the manufacturing level and competitiveness of a wooden door enterprise.