Although the currently used electrostatic powder spraying equipment has many advantages such as safety and environmental protection, beautiful coating, excellent characteristics and better coating quality, it still has the following problems to be solved:
(l) Selection of powder properties If the electrostatic powder currently used produces high-quality coatings, it depends on whether the powder has a positive or negative electrostatic charge. Generally speaking, a positively charged powder can produce a smoother coating. Coatings, while negative charges are less effective, and different properties of the powder will determine whether it can be positively or negatively charged. This aspect is still where manufacturers need to improve, hoping to break the limitation of powder selection as soon as possible.
(2) The color modulation of powders Because powders are always different from solvent-based pigments, the changes in color modulation are limited, especially it is difficult to make special colors such as gold and silver. Some paint manufacturers have problems in controlling color stability, often unable to maintain the same color for each batch of paint, resulting in color differences in the coating of customers' products. In fact, the quality of powders made in Europe is stable and has reached international standards, and most of the powders do not contain toxic metal components, and this aspect of technology is lacking in domestic manufacturers, because if there is no good formula, it does not contain heavy metal components. The powder is difficult to have a bright effect.
(3) The explosion hazard of powder and the toxicity of lead-containing mixtures. Powders are generally flammable and explosive and, within certain defined density limits of the powder and air mixture, form a potentially explosive mixture. In addition, although most powder coatings are non-toxic, some powder coatings contain lead mixtures, which will pose a certain threat to human health and safety, because the powder coatings contain toxic elements and lead in the dry film. The components of the mixture will migrate out in contact with human skin. If the lead content of the lead mixture in the powder coating exceeds 5% of the weight of the mixture, the powder coating cannot be used for food containers and children chewing or sucking. These are the issues that manufacturers must pay attention to when selecting or changing powders.
(4) Life of powder coating The current powder coating can only last for 10 years. With the increasing market demand, the pace of research on how to extend the life of powder coating needs to be accelerated.
