In the process of coating operations, we often encounter that the products produced have many pits, which seriously affect the quality of the final product. For this reason, we have conducted in-depth experimental exploration of this phenomenon and obtained the following experience for For your reference. 1 Paint viscosity For paint printing, the viscosity of paint is an important indicator of paint printing. The level of viscosity directly affects the appearance quality of the product. Take Jiachang White Codine 2202-530 as an example (the upper limit of construction viscosity is 180s and the lower limit is 140s). First, put it upside down for 15min, stir for 30min and then apply on the machine. Will the paint be adjusted by adding thinner to adjust the viscosity? First adjust the viscosity to the upper limit specified by the coating, the surface of the printed product will have "pitting", so we will adjust the viscosity of the coating according to the above operating rules Every 5s is adjusted down once, and then adjusted in turn? After repeated experiments, it was found that the "pit" (from high viscosity to low viscosity) on the surface of the printed product coated each time has a tendency to gradually decrease. When the lower limit is reached, "hemp" "Points are gone?" From this we conclude that the "pitting" that occurs due to the viscosity of the paint is caused by the viscosity of the paint being too high. 2 Material of rubber roller The rubber roller is an important part of the coating machine. The material of the rubber roller is an important factor that affects the appearance of the printed surface. Therefore, the rubber roller with lower density was replaced with a polyester roller with higher density, and it was finely ground. After the experiment on the machine, the "pits" due to the material of the rubber roller have completely disappeared. 3 Pressure of bottom roller The pressure of the rubber roller and the bottom roller is a technical indicator that directly affects the coating quality. We adjusted the pressure of the rubber roller and the bottom roller from small to large, and repeatedly experimented and proved that the pressure should be adjusted to 3 (starting from the first contact between the rubber roller and the bottom roller) without causing other problems. At around 8, it was observed that there were no "pits" on the surface of the coated print. 4 Environmental pollution Good products are inseparable from the surrounding production environment. The pollution of the surrounding environment will directly affect the quality of the product. Therefore, in order to eliminate the "pitting" caused by environmental pollution, we have thoroughly cleaned and isolated the host and the surrounding machines that can cause dust, effectively preventing the occurrence of "pitting". 5 Tinplate temperature The temperature of the original tinplate is also one of the important factors to produce "pitting". In the autumn and winter seasons, due to the low temperature of the original tinplate, the surface coating of the printed products that did not enter the drying room has poor fluidity. After entering the drying room for drying, the coating is based on the transfer mode of the transfer roller. When the place is heated too fast, it spreads to thicker places, forming "pits". Therefore, the original tinplate placed in the open air was moved to the forklift lane of the drying room and preheated in advance, so that the coating of the printed matter applied there was no "pit". After experimenting with the above five factors, we realized that during normal operation, we must also consider other factors that cause problems. In the future, we will carry out the construction strictly according to the above experimental data, so as to completely eliminate the "pitting", thereby improving our coating quality and making our printed products more clean and beautiful. Food Roll Stock,Roll Stock,Biscuits Roll Stock,Automatic Roll Stock Guangdong Danqing Printing Co., Ltd. , https://www.spoutpouchfactory.com
Exploration of eliminating coating pits