Jet printing

The Chromotronic machines, now called the Chromojet M and MS, have been particularly successful for tile printing, and a typical machine can print eight colours from a single traversing print head in which are arranged 512 jets (64 jets per colour). Printing speed depends on the definition (usually 10 or 20 mesh) and the number of colours to be printed (commonly four for most tile designs); a typical machine runs at 2–4 m min–1 with a print width of 2 m – that is, four tiles side by side. The tiles may be placed precisely on the transport belt to keep them in register; alternatively, several tile designs, slightly larger than the finished tile size, may be printed on a larger piece of carpet which is subsequently cut into tiles. This avoids a problem that can occur when individual tiles are printed, namely that the very edge of the tile may remain unprinted owing to the tufts being distorted either prior to, or during, passage under the print head. This defect is particularly noticeable if a white-base carpet material is being used. It is more common, particularly when printing logos, to use a predyed carpet as the base material because tiles can then be laid on the floor with the printed ones alongside plain ones of the identical ground shade.