Thanks to the growing popularity of eco-friendly sheetfed presses and the performance of UV inks and coatings on non-absorptive substrates like plastic, offset printers can participate more fully and profitably in markets previously hampered by the inability of offset inks to penetrate the plastic substrate, e.g., POP and display; credit, membership and gift cards; packaging graphics and labels; security and brand protection; etc. On the digital side, UV-curable wide-format ink-jet technologies are exploding in popularity, while digital roll-to-roll, digital cut-sheet and digital offset presses offered by KBA, Kodak, Presstek, Ryobi and Screen, among others, now feature UV options.
According to independent UV print consultant and former plastic printer Kurt Kroening, “Companies considering getting into the business of plastic printing would be well-advised to master the nuances of UV technology first, rather than risk expensive misfires.” A short list of the technical challenges associated with UV printing on plastic includes the need to adjust for a narrower window when setting the ink/water balance; the need to adapt printing profiles to compensate for the higher dot gain; and the need to control ink film thickness to promote curing.
Chemically or naturally biodegradable or compostable plastics made mostly or entirely from renewable resources represent one focus of an emerging industry intent on making products that enable users to control when and how the substrate degrades, while ensuring that the product remains viable and functional while still in use.
Technically, all bio- and petroleum-based plastics are biodegradable, meaning they can be broken down or degraded by microbes under suitable conditions; however, for all practical purposes, many degrade so slowly as to be considered non-biodegradable. What makes a given plastic “green,” therefore, is one or more of the following characteristics: (1) It is made from renewable ingredients; (2) it can be returned safely to the environment after use; and (3) it is manufactured in an environmentally friendly manner. One of the most familiar bioplastics is cellophane, a sheet material derived from cellulose plant fiber.