Research On The Process Of Particleboard Powder Coating

Particleboard is a kind of important artificial board,commonly used oil paint and many kinds of veneers for decoration,the painting decoration is of complicated process,low production efficiency,VOC emissions,pollution of the environment.Powder coating is with 100% solid powder,no VOC emissions in the production and use of the process of coating,it is widely used in metal materials.In recent years,low temperature fast curing powder coatings have used on wood,MDF such heat sensitive materials,but the application has not been reported in particleboard.Therefore,we use the low temperature fast curing powder coatings in particleboard surface to improve its surface properties and extend its service life,to achieve the green environmental protection in the production and use of the process,to provide a theoretical basis for the use of shaving board powder coating industry.This paper selects four different manufacturers of different thickness of particleboard,first do the comparison and analysis of basic physical and chemical properties test on particleboard,then screen the board suitable for powder coating finish,study the coordinating role of resistance,the preheating time and moisture content,do the research of process on the substrate to enhance the conductivity and spraying effect,finally select the board suitable for powder spraying and curing,and get the powder coating samples of particleboard,then use infrared spectrum,DSC and optical microscope to analysis the curing process and the quality of coating surface.The results of the study show that:1.The test and analysis of the physical and chemical properties of particleboard.Choosing four different manufacturers of particleboard,do the test on physical and chemical properties according to the national standard GB/T 17657-1999.Considering the profile density,electrical resistance,internal bond strength and thickness swelling and formaldehyde,Bao4 series of particleboard(Fujian Furen Wood Industry Co.Ltd.)has good physical and chemical properties and is suitable for powder coating.2.Study on the effect of moisture content on powder coating.Select the Bao 4-25(25mm in thickness)for the experiment,under normal temperature,when the moisture content is >9% powder is good,but after curing,the coating surface will have a lot of pinhole;when the water content is <9%,the the effect of powder becomes poor,especially on the edge which is very difficult to fly.under the preheating,when the moisture content in 6%-8%,the resistance is 108 ? orders of magnitude,it is suitable for electrostatic powder spraying,the amount of powder is 280g/m2,the appearance quality of the cured film is good,the film thickness of 160 ?m reaches the best range of film thickness,adhesion 1 grade which meets the requirement of the national standard,and the film quality is good.Based on the above analysis,we choose the preheating of spraying experiment.3.Study on preheating of powder coating.After the study of the surface moisture content and resistance under three preheating temperature of 70?,80?and 90?,we choose the preheating temperature of 90 for powder coating test on Bao4?-25 mm.In the preheating temperature of 90?,the moisture content and the resistance have a synergistic relationship which changes with time,when the time reaches 32 min,the moisture content is stable around 7.1%,the resistance to a minimum of 9.6 ×107 ?,then tends to be stable,the most suitable for electrostatic powder spraying,when preheated 3min after,the moisture content is in 6.0-7.3%,the resistance is in the 108 ? magnitude,fit the requirements of electrostatic spraying.4.In the coating experiment,in the preheating temperature of 90?,the preheating time of 5-15 min,while the moisture content reaches 6.0%-7.2%,the resistance of 4.8 ×107~9.2 ×108 ?,the effect of c powder spraying is good,the powder amount is up to 290 g / m2.In the preheating time of 10 min or 15 min,curing 140?/4min or 150?/3min,it reaches the best coating effect,the product grade is 1,surface scratch resistance is ? 1.5N,no the whole circle of continuous surface scratches,wear value is 69 r,the coating corrosion resistance and pollution resistance are good,the resistance to cigarette ignition performance is 4 stage,which meets the requirements of China's veneer particleboard standard.5.Study on the effect of surface treatment on powder coating.In a certain range of moisture content,the powder amount is not the same on board samples under different surface treatment.under the conditions of infrared oven temperature of 150?/3min of drying,the sample film quality is good in coated with conductive paint,adhesion of coating grade is 1,the hardness is 4H,good water resistance,without bubble and pinhole.6.Analysis of the powder coating particleboard with spectrum and microstructure.Analysis of infrared spectroscopy and DSC on the powder and the coating after curing,checking the curing degree of coating formed on the surface of the test board;observe the concave and convex of coating surface with optical microscope.