Flexographic printing presses use printing plates to apply ink to the substrates, such as a paper or cardboard. The plates are made from several materials, including rubber, plastic and photopolymers. Flexographic printing plates employ the relief approach in which the image is a raised surface. Only the raised portion of the plate comes in contact with the ink before the plate is applied to the substrate.
The diverse flexographic printing press designs make flexographic printing one of the most versatile approaches to printing. Most newspapers, for example, are printed on massive flexographic printing presses. Other common applications of flexographic printing include printing on boxes, labels, envelopes and bags.
Using a digital plate on a flexographic printing press is slightly different than using conventional plates. Digital plates offer less relief thickness than plates made through more conventional processes. The impression depth set on the flexographic printing press must account for this depth variance. To get sufficient ink coverage on the plate, the anilox impression on digital plates works best with a just over “kiss” depth.
Central impression printing is a specific type of flexographic printing. The presses use one large impression cylinder to move the paper. As the impression cylinder moves, the paper passes through a series of smaller print cylinders. A printing plate is attached to each print cylinder and applies different colors of ink and different images to the paper.
Businesses can use central impression printing for a wide range of needs. CI presses can print onto several substrates, such as aluminum packaging, paper bags and shrink sleeves. This makes central impression printing particularly useful for manufacturers that want to keep the entire packaging process internal rather than outsourcing package printing.
New printing presses can prove prohibitively expensive as the prices range from the thousands to tens of thousands of dollars. Used printing presses offer a more economical alternative for entrepreneurs, startup companies and cost-conscious businesses with heavy printing needs. As with any purchase of used equipment, used printing presses should be purchased from businesses that offer guarantees that the machine is in working order or a specialist should examine the machine prior to purchase.
Many businesses choose to outsource their printing needs in the beginning out of convenience or to control startup costs. An in-house printing press and the facility to house it represent significant infrastructure costs. When businesses reach a certain threshold of profitability and decide to bring printing in-house, many opt to purchase a used commercial printing press. A used commercial printing press offers the same essential functions as a new one, but typically saves thousands of dollars in purchase costs.
Buying a used printing press, though cheaper than a new press, requires some due diligence. If possible, speak with the previous owner about the reasons for selling the press. Ask whether the used printing press comes with the original documentation, such as manuals. Ask to see the printer work in person or, if respective locations make that impractical, via a live video feed. Examine the quality of the finished product to make sure the machine isn’t suffering from an expensive internal malfunction or requires an immediate replacement of rollers.