Plastic Parts Mature Technology
Plastic parts water-based Paint Construction equipment demand
2.1 Spraying Construction method
The solvent-type paint automatic spraying machine adopts the internal power-adding method. And the water-based paint in the beginning of use all for the external power-adding way. The external power-adding method has the advantages of simple transformation, Plastic Parts fast speed and low cost for the conversion equipment with mature technology and solvent paint to water-based paint. However, due to external electric finger causes, but also caused some shortcomings: fingers easy to accumulate paint, cleaning frequency increased. Plastic Parts The finger is sensitive to the moving speed and ambient humidity of the machine, which will result in the decrease of the efficiency of the paint construction and affect the appearance quality of the film. With the development of technology, now the internal power of water-based paint has been applied in the plastic parts coating line. Plastic Parts There are two main ways to add electricity: one is to spray the water-based paint on the robot's arm before each spraying, finish the spraying after spraying, and then return to the original in situ for painting. Another way is to use two sets of paint cans, can be placed outside the spray room, a set in the spraying, another set of cleaning, can achieve continuous production. At present, Plastic Parts the provision of water-based paint internal electric power spraying equipment manufacturers are mainly D U RR Company and Fanuc Company.
2.2 Flash Drying
It is well known that the wet-touch process of paints and varnishes requires that the solvent or water content on the surface of the paint should be volatile to a certain degree before the varnish is carried out to ensure quality and appearance. In general, the time between the La 5min of the lacquer and the varnish is measured. Solvent-based paints rely on their own flash-dry to achieve this requirement. Plastic Parts Water-based paints need to be heated to bake to meet the requirements of dehydration rate. And in the color paint after spraying into the heating flash dry, heating flash channel design is usually recommended for octagonal, because this design can maximize the use of thermal efficiency, to ensure that hot air spray perpendicular to the body surface, so that can be properly reduced to meet the dehydration rate under the premise of the process time, reduce process length.
In order to meet the requirements of heating and dewatering of water-based paints, the heating and flashing zone must be designed to adjust temperature and humidity. Plastic Parts The most common way to adjust the humidity is to add fresh air to the recycled air. The replacement ratio of fresh air depends on local environmental conditions. In dry winters, only a small amount of fresh air (5%) can be replaced, while in the humid season (> 27 Shan and 80% relative humidity), very large amounts of fresh air may be needed.
2.3 Transmission and adjustment paint system
Many aspects need to be considered at design time. Solvent-type paint system piping materials are more casual, stainless steel and carbon steel systems are available, Plastic Parts and water-based paint pipeline must choose stainless Steel plus passivation treatment design. Back pressure design must use a low shear force of the back pressure valve. water-based paint on the level of the liquid level control system also has a higher demand, because the water-soluble liquid in the container after the drop in the liquid level, attached to the container wall paint. Because the evaporation of water easily produces powder spalling, and can not be eliminated because of the addition of new paint, thus affecting the quality of spraying. The solvent-type paint because of the new paint when the solvent itself can flush the inner wall of the container, then no such situation occurs. In many foreign design, Plastic Parts paint in the supplier plant has been fully adjusted, so use a storage tank to store paint, and the incoming packaging directly on the high shelf on the shelves by gravity to keep the liquid level of the paint tank. In the domestic, Plastic Parts basically still uses the barrel packing, therefore needs in the incoming barrel, the paint storage cylinder and the transport paint cylinder maintains the liquid level stability in the cylinder.
3. Plastic parts water-based Paint Construction Technology
Water-based paints have some special requirements for storage and handling. Because of the nature of water, water-based paint is very sensitive to temperature, if water-based paint stored in the environment below 0 degrees, the solubility of the paint will change, resulting in some of the important components of the paint precipitate. In this case, the water-based paint will become uneven and may precipitate grain. Plastic Parts Even if the water-based paint is heated again, it will not be able to return to a homogeneous state, the characteristics of the paint would be completely destroyed. On the other hand, because the paint contains water, water will corrode the traditional storage of paint containers, while the paint itself is susceptible to the effect of bivalent iron ions to change its rheological properties. This requires that all containers for water-based paints be made of stainless steel or plastic.
The temperature condition is 5 to 30, in the transportation process needs to be according to the ambient temperature heating or the cooling, carries on the transportation vehicle must be able to carry on the control temperature, the water-based paint storage area and the adjustment paint must have the temperature control function.
In general, water-based paint can be stored stably for 3 months, and over this time it will be necessary to re-evaluate the paint, otherwise the quality of spraying will not be guaranteed. The specific retention time may vary slightly depending on the paint supplier.