Methods and precautions of metal powder coating

Metal powder coating refers to all kinds of powder coating containing metal pigments (such as copper gold powder, silver aluminum powder, etc.) Because metal powder coating can show a bright and luxurious decorative effect, it is very suitable for spraying indoor and outdoor objects such as furniture, ornaments and automobiles At present, dry blending method is mainly used in the domestic market, and binding method is also used in the international market I coating method of metal powder coating: friction spray gun is generally not suitable for spraying of metal powder coating In most cases, it is recommended to use electrostatic spray gun for coating and half loading Due to the metal pigment contained in this type of product, good grounding of the system shall be ensured when using electrostatic gun for construction, and low electrostatic voltage and powder output shall be set to prevent ignition during spraying The effect of forming coating film has a great relationship with the setting, quality or brand of spray gun There may be a large amount of metal powder accumulated at the discharge needle of the spray gun after long-term spraying, which needs to be cleaned regularly by the constructor II Luster of metal powder coating In most cases, due to the large error, we do not recommend to use the luster meter to measure the luster of the metal appearance coating, but only use the visual comparison method to judge whether it is consistent with the standard template III recyclability of metal powder coating: for powder manufactured by dry mixing method, there will be separation phenomenon in the process of spraying and recycling, so there will be certain difference between recycled powder and new powder in the content of metal pigment, which may lead to different appearance of coating film and phenomenon of color deviation This is due to the difference in properties between metallic pigments and powder particles Experts from China epoxy Industry Association suggest that the ratio of recycled powder to new powder should be at least 1:4 If the powder coating made by the adhesive fixation method is used, the recycled powder can be reused completely because the ratio between the metal pigment and the powder particle is relatively fixed 4 The coating layer of metal powder coating: the coating layer is sprayed on the metal powder coating with the following advantages: enhancing the stone resistance of the metal powder coating; increasing the aesthetic effect of the metal powder coating; thoroughly solving the abradability of the metal pigment; improving the weather resistance of the metal powder coating film In order to ensure the appearance effect of the coating, it is required that the workpiece sprayed for the first time shall not be polluted Therefore, it is generally necessary to have a fully automatic spray line and two sets of independent spray rooms for separate coating It is recommended not to spray the glossy coating in general It can only be used when the requirements are very high, such as: high-end home appliances, car wheels and outdoor use (to ensure weather resistance), etc 5 The erasability of metal pigment, whether it is powder made by dry mixing method or by bonding fixation method, can not completely solve the problem of erasability of metal pigment The only way to solve the problem is to spray a transparent coating on the metal powder coating Vi methods to keep the appearance of metal powder coating consistent 1 For the same product, try to use the same batch of metal powder coating to avoid the problem of the difference between batches of powder coating Try to keep the spraying conditions stable Use the same spraying equipment, use the same voltage, air pressure and other parameters; try to keep the distance between the spray gun and the workpiece unchanged, try to keep the stability of the film thickness; ensure that the powder coating has been fully fluidized before spraying; when using the recycled powder, ensure that the ratio of the recycled powder and the new powder is at least 1:4; try to avoid using the workers with complex spraying shape or deep depression of the metal powder coating Pieces; we suggest that multiple pieces for assembly should be painted at the same time.