inglés al español Técnico/Ingeniería TI (Tecnología de la información) Remanufacture of ink cartridges

In the context of ink cartridges remanufacture. Anyone knows what a "screen" is inside a cartridge? The term appears all over the place, here are some paragraphs:

This is especially problematic when this (ink) thickening occurs in the area between the **internal screen** and the print head.

A film of sludge may slowly slide onto the **screen** at the bottom of the barrel, making ink starvation likely during printing by clogging the screen

Lying on its side causes whichever side of the barrel was lowest to be coated, while standing upright may create a tubular plug with the **screen** at its base, etc.

I have been told it functions as a block or barrier...

Thanks a lot

Noelia