Pre-metering technology applies coating to media

Manufacturers apply different techniques to apply coatings to media. These technologies fall into two broad categories: pre-metering techniques and post-metering techniques. The main difference between the two is how to achieve the required coating weight. The pre-metering technique is to apply only a precise amount of paint, similar to squeezing a toothpaste at a controlled rate. After that, the metering technique involves applying a suitable amount of paint on the media. After metering, the excess is removed and the coating is recycled.

Pre-metering techniques include single-layer and multi-layer slot die extrusion coating, curtain coating, and multilayer grading coating. These coating methods are highly homogenous and each method is equipped with a pumping system that ensures that the coating fluid is delivered in one place and does not need to be repeated. Post-metering techniques include gravure, roll and reverse roll coating, these techniques are generally used to coat thinner adhesion-promoting coatings.

Regardless of the method used, accuracy and consistency are key to coating inkjet media. The thickness of the coating is one of many parameters that the manufacturer monitors and follows strict technical standards because the thickness of the coating affects the color, density, and color saturation of the final printed image. Between one roll or each roll, or between one job and the next, the inconsistent thickness of the coating will eventually give the user a different color product. This is why it is so important to carefully control the paint and assess the quality of the paint. It guarantees that the products you buy today will print the same effect as the products you bought last month.

Source: China Washing & Dyeing Industry Information Center