High pressure printing


High pressure printing

Print is growing and has a new lease on life in the production of high-quality packaging. Trelleborg is one of the few suppliers that can meet the industry’s more challenging needs.

The print industry, having weathered the advent of all things digital, is looking at brighter horizons in the field of high-quality packaging. Today, people do not just expect functional packaging. They want something of beauty that incorporates different dimensions, such as embossing, very high definition graphical elements, superb color and metallics that shine out. 

The printing process that has seen the greatest decline is rotogravure, traditionally used for magazines, catalogs and packaging. Involving engraving of the printing image onto a cylinder, it was virtually replaced when the quality of offset printing reached a comparable level. The main reason for this is the lower production cost of sheet-fed plates when printing short-run jobs. Production on offset machines has moved from 60 lines to 80 or even 100 lines per centimeter, and traditional print screens have been changed to stochastic screens. These use frequency modulation to change the density of dots according to the desired gray level, creating incredibly high resolution images. The demands on the surface finish of blankets are therefore much higher. Tolerances are small, so as much ink as possible is transferred. The slightest amount of accumulation of ink causes a loss of dot definition. Now that offset sheet-fed printing machines are producing up to 20,000 printed sheets per hour, the printing blanket is a more critical element than ever in ensuring that the quality of print is as perfect as can be. 

Trelleborg raises the bar all the time, trying to perfectly match its blanket to the surface that is to be printed. For packaging that could mean soft surfaces, a glossy paper, corrugated card that must not be crushed, the flimsiness of film or the hardness of metal. The proper compressible layer in a printing blanket is the key to perfect print. It provides rebound to give the right pressure to transfer ink from the blanket to the print surface. High pressure is required to transfer ink to a metal surface, so usually blankets are used that have no compressible layer. When printing at 100 percent saturation these blankets are adequate. 

Printers and their customers now demand the same quality of print on metal as on paper or cardboard. For the production of images, where screen and dot reproduction need to be extremely sharp and clean, a compressible layer is required to ensure clear and precise images. Trelleborg is the only manufacturer of printing blankets that can offer a blanket with the proper compressible layer for metal decorating.

For more information: www.trelleborg.com/printing