| Flexography also known as Flexo or roll-to-roll or roll | | | | |
| label printing. | | | | The Flexo press can have another attachment; that is |
| This method prints labels from a roll of stock to a | | | | known as a turn bar. A turn bar is an apparatus that |
| finished roll of completed labels. Material is loaded onto | | | | turns the stock over so you can print on the liner |
| one end of the Flexo press and the material is | | | | without removing the print job from the press. The |
| threaded through the press and each print station. | | | | other styles of printing do not offer this feature, if a |
| Laminating and cutting stations are set up at the end | | | | print job calls for a coupon on the liner on a letter, or |
| of the press so completed labels are produced in one | | | | offset press the press operator would remove the |
| pass on the Flexo press. The printing head of a Flexo | | | | stock then reload the stock to print the liner. |
| press is on a cylinder and prints directly, on to the | | | | |
| substrate. This differs from letterpress that uses a flat | | | | |
| bed, or offset presses that uses a cylinder but offsets | | | | The Flexo press also has an in-line cutting station. The |
| the printed image to a blanket. | | | | labels can be left on the roll or can be individually cut |
| | | | | into single units. In the other styles of printing, cutting of |
| The letterpress uses set type in a block, the offset | | | | the label is accomplished off-line. |
| press uses a plate, but transfers the image to be | | | | |
| printed onto a blanket, and the blanket transfers the | | | | The advantage of the Flexo printing is once the |
| image to the substrate. The Flexo press uses plates | | | | machine is set up to print, the press operator would |
| that are made from a flexible type of rubber, much the | | | | not have to touch the stock again until the completed |
| same as a rubber stamp, which comes in direct | | | | labels are taken off the press. The other advantage of |
| contact with the substrate. | | | | this method of printing is it is very fast. Fast enough |
| | | | | that to see what is being printed a low-tech strobe light |
| Printing plates for the Flexo printing heads can be | | | | is used. The strobe light is blinking at the same speed |
| made in several different ways. One method uses a | | | | of the printed labels thereby freezing a printed label. |
| light-sensitive polymer. A film negative is placed on top | | | | This was necessary so the press operator could |
| of the light-sensitive polymer plate, which is then | | | | make sure the label is being printing correctly. The |
| exposed to a ultra-violet light source. Where the light | | | | ultimate advantage of this type of printing is the low |
| passes through the film negative it hardens the | | | | cost of the labels. |
| polymer. Conversely, the areas that block the light | | | | |
| from illuminating the polymer the polymer material will | | | | |
| stay soft. The soft areas of the plate are washed | | | | Flexography printing is designed for large quantities; |
| away in a tank of water or solvent facilitated by a | | | | because set-ups and make-readies are expensive, |
| scrub brush. | | | | thus roll label printing is not a good solution for 500 |
| | | | | labels. The normal minimums for this type of printing |
| Another way to make Flexo printing plates is a | | | | would be 1,000 labels. Large quantities for this method |
| computer-guided laser to etch the image on to the | | | | of printing would be 100,000-millions. |
| printing plate. Such a direct laser engraving process is | | | | |
| called digital plate making. | | | | |
| | | | | The disadvantage of roll label is not a good solution for |
| Another process to make the printing plates is through | | | | small quantities. In addition, the inks used by most roll |
| a molding process using a zinc plate to mold the | | | | label manufactures are water based and will fade in |
| rubber printing plate from. The molding process of | | | | direct sun light. |
| make Flexo plates is hardly utilized today, since light | | | | |
| sensitive and laser digital is more cost effective, and | | | | Flexography printing can print on paper and plastic |
| quicker. | | | | substrates, and is a great solution for inside |
| | | | | applications. This type of printing is used to brand |
| | | | | consumer products from salsa to televisions, and |
| The Flexo presses have different printing stations for | | | | warning labels for inside factory machines. |
| each color. Some machines have three colors stations, | | | | |
| some have six color stations. The cost of a | | | | I must note here that there are exceptions to these |
| Flexography print machine is a function of the number | | | | facts, so contact a company that manufactures roll |
| of color stations and the web width; a 3-color press | | | | labels to see if a roll label is an appropriate solution for |
| narrow web would cost much less than that of a six | | | | your application. |
| or eight color wide web Flexo press. | | | | |