该小孔由基板于膜层表面,形成腐蚀通道。 彩涂板涂层表面周化后出现类似用针刺成的细孔,或像皮革毛孔那样,较大的称为麻点,是由于彩涂板涂层中能人T空气海和产生的其但气渔股裂,且在涂圆化前不能通过施平去推
产生原因:
(2)确保辊涂室的相对湿度不大于85%,确保钢带表面干净无油、水和被污染;(3)按工艺要求控制好辊涂速度,一次涂层不能太厚,湿膜厚度最好不超过 40pm;(4)固化炉的温度应从人口至出口方向由低温至高温设置,让溶剂能充分挥发。
The hole is formed by the substrate on the surface of the film to form a corrosion channel. The appearance of pinprick like pores on the surface of the coating, or larger pores like leather pores, is called pockmarks. It is due to the air and sea in the
hu'ao coating, but the air and fish cracks, and can not be pushed by leveling before rounding
The causes are as follows
(1) The humidity of the construction environment is too high, and there are water, oil or other impure substances
left on the surface of the steel strip, which are not cleaned up. (2) the viscosity of the coating is too high, and the tightness and covering power of the coating itself are poor( 3) When the coating is produced, it carries air and moisture, or the
storage temperature is too low;
(4) The coating is stirred intensely for a long time, and air is mixed into the coating to generate numerous bubbles;
(5) The coating speed of roller coating machine is too fast, the coating is too thick,
and the solvent is wrapped in the coating and difficult to volatilize;
(6) The curing temperature of the coating at the initial stage of solvent volatilization is too high. Because the solvent volatilizes too fast, the film itself has no time to make up for the holes, forming a series of small holes, namely pinholes.
Exclusion method:
(1) the paint should be stored at suitable temperature after entering the warehouse, so as to prevent the occurrence of defects such as precipitation, crusts and gels caused by low temperature.
(2) The viscosity should be adjusted properly, and the mixing time should be avoided too long;
(2) Ensure that the relative humidity of the roller coating chamber is not more than 85%, and ensure that the surface of the steel strip is clean and free from oil, water and contamination( 3) The roller coating speed should be controlled according
to the process requirements, the first coating should not be too thick, and the wet film thickness should not exceed 40 pm( 4) The temperature of curing furnace should be set from low temperature to high temperature in the direction of population
to outlet, so that the solvent can be fully volatilized.