Discussion on the problem of orange peel in powder electrostatic spraying

orange peel is a common and difficult to overcome in the coating process of the leveling problem, many factors, greatly affect the flatness of the coating filmThe orange-skinned surface can be said to have a greater impact on the appearance and decoration of the productThe use of orange peel for powder coating manufacturers is an urgent problem to be solvedThe production of orange peel in powder coating is closely related to the characteristics of powder coating itself, namely, the effect of leveling and the influence of equipment in coating production and the control of process parameters in the coating process1 The cause steamand and solution of the problem of orange peel
1.1 powder coating's own characteristics on the cause of the orange peel problem
1.1.1 powder coating in the use of resin molecular weight
powder coating when the composition of the molecular weight of the resin is more importantAlthough the high molecular weight resin has better weather resistance, but because of the powder in the flow peacetime, in the melting state of the powder viscosity is larger, leveling is more difficult, resulting in the appearance of orange peel phenomenonFrom the point of view of viscosity, the choice of low molecular weight resin is conducive to improving the leveling performance of powder coatings, but the weather resistance of low molecular weight resins is poor, which requires powder coating manufacturers to consider the selection of synthetic raw materials1.1.2 effect of powder particle size distribution
Generally speaking, when the particle size is greater than 75 m of powder proportion is too much, will cause the film's leveling performance is poor, easy to produce orange peel phenomenonAt the same time reduce the spray area of powder units, and in the construction process, the electrostatic effect of powder coatings becomes poor, easy to cause de-powderingWhen the particle size of less than 10 m of powder proportion, due to the powder coating dry powder flow is slightly poor, will cause the spray can not be sprayed powder, stick gun head and other spray construction problems1.1.3 the effect of tiling agent
is an important additive in the production of powder coatings, manufacturers in the production of powder coatings, are added to the leveling agent in order to improve the leveling performance of powder coatings and average coating performance, improve film flatness, reduce the phenomenon of orange peel1.1.4 The effect of powder stability powder coating steaming the stability of powder coatings shows that the cross-linking reaction of molecules under storage conditions, the more intense the cross-linking reaction of the powder, the greater the molecular weight of the powder, reflecting the increased viscosity of the powder at the curing temperature, the uneven flattening characteristics, and the susceptibility to orange peel