Essential Reading for New Enamel Manufacturers: Practical Tips for Hand Spraying Enamel on Cast Iron Color Pots

In the production process of enamel cast iron color pots, the method of "two coatings and two firings" is quite common, which means that 2 to 3 spraying operations are required throughout the process. This is especially true for products with complex shapes and rich details, where hand spraying shows its irreplaceable advantages. However, the quality of the finished product from hand spraying largely depends on the skill level of the operators. Therefore, for manufacturers new to the enamel production field, it is crucial to ensure that workers master efficient hand spraying techniques. Below, we will delve into practical tips for hand spraying enamel on cast iron color pots.

In wet spraying operations, the nozzle diameter adjustment should be set according to the specific type of enamel product and the properties of the glaze slurry. The supply method for the glaze slurry is flexible and can be achieved through the built-in glaze cup of the spray gun or an external pressure tank. When spraying enamel cast iron pots, the following points should be particularly noted:

1.Air Pressure Adjustment: When spraying the pot handle, appropriately lower the air pressure of the spray gun to ensure a fine and even coating; for the pot body, increase the air pressure to achieve higher spraying efficiency.

2.Ground Coat Thickness: The ground coat should be sprayed thinly to avoid difficulties in subsequent processing due to excessive thickness.

3.Coating Uniformity: The thickness of the sprayed enamel should remain uniform and moderate. The recommended dry grinding thickness after drying should be controlled between 160 and 200 microns to ensure the final quality of the product.

4.Stable Air Pressure: Maintain the spraying pressure around 0.4 MPa, ensuring stability. Additionally, the compressed air must undergo strict filtration to ensure it is free of water and oil, preventing any adverse effects on the coating.

5.Nozzle Distance: The distance between the nozzle and the workpiece should be maintained at around 30 centimeters. If too close, it can lead to an orange peel effect, while being too far may result in a grainy coating.

6.Color Management: When spraying different colors of glaze on the inside and outside of cookware, matching lids should be used to properly cover areas and prevent cross-contamination of glaze powders.

Additionally, the glaze used in manual spraying has requirements for fineness and density. To achieve better atomization, the glaze for wet spraying should be finer compared to immersion glazing. However, care must be taken regarding the quality after drying and firing; overly fine glaze can lead to defects like cracking and shrinkage. At the same time, slightly increasing the density of the glaze can be beneficial, as high-density glazes reduce spraying time and improve production efficiency. For instance, in single-surface spraying operations, the nozzle only needs to pass over the surface a few times to achieve the desired thickness.

In summary, mastering these key techniques in manual spraying is crucial for enhancing the product quality of enameled cast iron cookware. Newcomer enamel manufacturers should pay close attention and provide thorough training for workers to ensure they can flexibly apply these techniques in practice, thereby producing high-quality, high-value-added enamel products.