In-vacuum selective metallisation made possible with SelectMet from BOBST

The new and revolutionary BOBST SelectMet system incorporates BOBST F&K heritage flexo printing technology into a BOBST vacuum metalliser and is a simpler and more cost-effective alternative to the traditional de-metallisation process without the complexity of special lacquers and chemical baths. The innovative BOBST SelectMet process runs at speeds of up to 400m/min on the BOBST K4000 platform. This provides greater flexibility as one machine can be used for two processes, both standard aluminium metallisation and selective metallisation without compromise. SelectMet is only available in the most commonly used metalliser widths in the converting industry: 1,250 mm and 1,650 mm.

Flexo printing unit inside vacuum chamber

The flexo printing unit is located inside of the vacuum chamber and the print head position can be moved accordingly depending on which process is to be run; for selective metallisation the print head moves towards the coating drum and then retracts back to a home position (away from the film web path) for standard metallisation.

Minimum oil consumption

This inline vacuum metallising process consists of a special printing oil which is applied at room temperature to the web in a very thin layer to produce the desired pattern. The low volume Anilox Cells ensure minimum oil consumption (down to less than 0.5 g/ sq m). The polished Anilox roller combined with a high precision Doctor blade made out of carbon fibre allows a more efficient and accurate oil metering.

Unlike the traditional and rather messy oil boilers, in the unique BOBST SelectMet system, the oil is loaded at room temperature through an external oil bath. This results in a much cleaner selective metallisation process. The location of the oil bath outside the vacuum chamber means that additional oil can be added during production to save time and to enable longer runs.

Quick and easy sleeve change

Another key feature of the new BOBST SelectMet is the quick and easy change of the printing sleeve. The printing unit retracts and aligns itself with the viewing port located on the side of the machine which gives easy access to the printing roller though the porthole window. The printing sleeve itself is a one piece cylindrical polymer sleeve which can be easily loaded with the aid of an air flotation bed. The quick release bearing house allows sleeve changeover in less than ten minutes. BOBST SelectMet incorporates an interchangeable bridge adaptor which allows the use of different diameter printing sleeves.

Faster, more accurate printing for a variety of applications BOBST SelectMet provides faster, more accurate printing with metal onto film substrates and allows for the production of creative, high resolution patterns and greyscale images. A flexible and versatile oil printing process system; BOBST SelectMet provides a wide range of addedvalue applications for specialist converters such as:

• Innovative decorative packaging filmsproduction of cutting-edge decorative films which can be used for eye-catching packaging to attract consumers’ attention.
• Stripe metallisation– leaves a window of un-metallised film that allows product visibility and evokes desire towards impulse purchases.
• In-register selective metallisation onto preprinted webs– pre-printed film is used as a base resulting in complex patterns incorporating both coloured and metallised areas.
• Anti-counterfeiting applications– production of high resolution selective metallisation used in security threads and holographic foils that offer protection against counterfeiting in banknotes and other security applications.

Also available is an optional ZnS source for production of decorative holographic films with enhanced brightness to reduce imitation and provide high brand recognition for security and protection applications.