Five major defects that most hinder paint decorati

Five defects hindering paint decoration

five defects hindering paint decoration

September 18, 2014

[China paint information] now with the development and changes of paint varieties and coating methods, there are many coating defects in China, and it is difficult to find the causes. So far, there are still many defects caused by unknown reasons. What is more subtle is that although some defects will occur, they will disappear automatically after a period of time

now, with the development and changes of 21187-t4 coating varieties and coating methods in China, there are many coating defects and it is difficult to find out the causes. So far, there are still many defects caused by unknown reasons. What is more subtle is that although some defects will occur, they will automatically disappear after a period of time. The following expenses may lead to the influencing factors of coating defects, but the defects are often caused by the interaction of many factors

(1) factors of the coating itself

as mentioned above, the coating is composed of film-forming substances, solvents, additives, coloring materials and other components and a variety of raw materials, and its performance is composed of various components to complement each other. Generally, the prepared coating is in a quasi stable state, so it is prone to defects caused by various external conditions, such as e.30 ± 3mm/min or 25 soil 2.5mm/min due to improper storage environment and long storage time; The degree of rise or curing is the inevitable result of the tendency of the coating from quasi stable state to unstable state. Another example is the unreasonable design of coating formula, improper selection of raw materials, problems in manufacturing process, inspection, shipment, packaging, transportation, etc. In particular, the coating is carried out according to the process specified in the product specification of the coating manufacturer, and defects still occur. At this time, we can find out the reasons from the coating aspect

(2) influence of substrate properties

as mentioned above, wood and wood materials are unique coating substrates at the end of 2015, with water content (water is easy to move), porosity, uneven material and material properties, and more factors forming defects. The unrepaired solid wood substrate itself has many defects (wormholes, cracks, roughness, grease, oil, etc.), which will directly cause coating defects. The high moisture content of wood and the continuous movement of moisture in and out not only cause various defects before and after painting, but also are the main reasons for the cracking and damage of the paint film of wood products after use. Therefore, wood coating must first fully understand wood, and then do a good job in the quality management of wood coating, so as to reduce the possibility of many defects. Therefore, when coating defects occur, the factor of substrate cannot be ignored

(3) coating process factors

when the factors of coating and substrate can be controlled and eliminated, defects are mostly caused by unreasonable coating process design and lax implementation. The coating process here includes the specific coating process, the methods and tools used in each process. 4. Whether the procedures of repeated loading and unloading equipment of hardness tester, especially the procedures of repeated processes such as drying and grinding, are reasonable, and whether the process conditions and process parameters of various processes are normal and accurate. For example, the selection of coloring and hole filling materials, whether the primer and finish paint are matched, the proportion of paint mixing, whether the variety and dilution rate of diluent are appropriate, whether the tools and equipment are equal, whether the spray gun nozzle and air pressure, and whether the function of oil-water separator are normal, especially the coating curing conditions (temperature, humidity, ventilation, dust removal, drying time and stage, etc.)

(4) painting environmental factors

wood painting, especially the painting of high-grade wood products, is a fine process, which requires a good environment. If the workshop lighting is insufficient, it will inevitably affect the accuracy of the line of sight. It may change color inaccurately, and the spraying thickness is uneven. The defects (such as color difference, sagging, and uneven thickness) that can be found visually and avoided in time could not be found in time. The temperature and humidity sprayed on the dry site are not controlled, the workshop ventilation is insufficient, or the wind speed is not appropriate, and it is difficult to volatilize the solvent, evaporate the solvent, and discharge the paint mist. In particular, the sanitary conditions of the spraying and drying sites are poor, the air dust removal and purification are not enough, and there is still dust in the ceiling, walls, floors and clothing. It also includes sawdust from wood machining, abrasive debris from substrate grinding, pollution sources not caused by itself around the environment of the coating workshop, especially the air pollution containing high lipids, which falls on the top of the coating through air transmission

(5) coating technical factors

the coating engineering is implemented by the operator, and the coating process is designed and managed by technicians. The quality of engineering and technical personnel is poor, and there is no relevant coating It is difficult to control the normal progress of painting project and avoid defects without certain practical experience or serious and responsible work. The above-mentioned influencing factors can be solved by human factors, so coating technology is also a key influencing factor