Metering rods are used to apply precisely controlled amounts of coatings to paper, film, foil and other substrates. One of the challenges for coating technicians is understanding how to monitor and measure rod life. In order to optimize the use of the coating metering rod and replace the coating metering rod at the correct time to avoid quality problems.
Metering rods are usually out of service when:
They can no longer draw down coatings of sufficient thickness;
The scratch-applied coating is no longer smooth and uniform.
How to judge the life of the coating metering rod and whether it needs to be replaced? Some common methods are as follows:
1. Measure the coating weight;
2. Production tracking;
3. Surface brightness;
3. Visual coating quality inspection;
But no matter what method is used, in most cases, the main reasons for the scrapping of coating metering rods are nothing more than the following:
1. Wear and tear
2. Blockage caused by poor cleaning
3. Linearity
Abrasion is a function of the substrate and applied coating pressure and is not discussed much here. In terms of cleaning, if possible, clean the machine as soon as possible when it is not in operation. For water-based paint, immerse the stick in warm water mixed with detergent (liquid dish soap) immediately after use. For paints containing industrial solvents, immediately after use dip the stick into a container of the solvent used in the paint. At the same time, when transporting or installing, especially ensure the straightness of the wire rod to avoid bending.
