Kolding, Denmark - At the ICE Europe 2013 stand, the TRESU Group, global supplier of flexo printing technology and printing lines, showed how its ancillary products enable automated control of flexo ink pressure, viscosity and temperature in a diverse range of narrow and mid-web flexo, coating and offset printing situations. Highlights were a new ink supply system and a range of chamber doctor blade systems that eliminate foaming and enable smooth laydowns. 

F10 iCon Ink Supply System

TRESU’s new F10 iCon pump features TRESU’s own patented viscosity and flow control, as well as temperature control over the ink as it circulates from ink bucket to anilox roller.  This keeps the ink at constant viscosity to ensure stable ink density on the printed substrate, and constant pressure and flow to stop air mixing with ink in the anilox chamber, in turn preventing blistering and ink starvation. Its airtight environment allows safe handling and storage of solvent inks in environments where solvent evaporations are likely. 

Other features include automatic cleaning after each production run and touch-screen operated real-time viewing. Cleaning cycles are completed in less than a few minutes. Strokes are counted to determine when fresh ink is pumped into the system, to ensure precise amounts are dispensed to the chamber, leaving minimal residue at the end of the production run. Excess ink can be returned to the bucket for reuse, without wastage. The pump minimizes manual intervention of the ink flow. This is especially beneficial for central impression (CI) presses, where a closed architecture makes ink control and leakage prevention a manually intensive affair during the production run.

The F10 iCon Ink Supply System is 1000mm height x 500mm in both width and depth and has a flow range of 5 to 30 litres / minute.

Henrik Kristensen, sales director of TRESU Ancillary, says: “The move to shorter production runs in flexible packaging markets means a constant focus is needed to reduce setup times and make the process less manually intensive. CI press builders have responded by increasing the colour stations from four to up to ten units, so that operators may prepare redundant stations for the next job during production time. This may save downtime, but results in a more complex configuration that restricts access to tooling.  TRESU’s programme of Chamber Doctor Blade System with pump and washing system improves productivity and ensures full control at the touch of a button.”

Chamber Doctor Blade Systems

TRESU’s chamber doctor blade systems cover all flexo printing and coating requirements. These enable direct transfer of the ink or coating to the cells of the anilox roll. This simple process requires minimal manual intervention because the anilox cell volume determines ink / coating laydown, ensuring consistent results. 

Benefits include increased gloss values for better reflection and more efficient drying because the whole substrate area needs the same energy to dry. Ability to achieve consistent ink laydowns allows improvement of ink yields by up to a fifth compared with double-roller doctor blade alternatives. 

TRESU incorporates a number of unique features into its systems, that enable accurate pressure control, efficient temperature regulation and cleaning, fast blade-changeover and airtight sealing of the chamber in order to accelerate changeover times, reduce maintenance requirements, increase yields and enable precise, consistent and even laydowns, free of microfoam and blisters, at faster speeds. 

A proprietary, patented rubber Seal System forms a perfect, airtight closure, eliminating leakage at top speeds. Another advantage of the airtight environment made possible by the seals is that leftover ink can be stored for long periods, without evaporation or perishing.

Pressure of the ink or coating is maintained at a constant rate. The operator raises the pressure of the ink or coating inside the chamber and against the anilox roll, creating a wall of liquid at the point where the rotating cells meet the blade.   This prevents air-bubbles, which can cause ‘microfoaming’, from entering.

The company’s fast ‘E-Line’ doctor blade-changing system enables blades to be slotted into position and released safely, within one minute, by a clamp. 

The FlexiPrint IMW E-Line Chamber Doctor Blade System is designed for smooth, defect-free, splash-free laydowns of solvent-, water- or UV-inks on virtually all paper, folding carton and film substrates. The unit has an ink volume of between 1.35l/m and 2.2l/m depending on chamber size, and is suitable for anilox diameters between 64mm and 250mm, web-widths up to 1800mm and printing speeds up to 500m/min.

TRESU’s narrow-web chamber doctor blade system, the FlexiPrint Reservoir Chamber Doctor Blade system, has a ‘closed cassette’ design. For UV and water-based inks and has no moving parts and works without a pump. With minimum volume requirements only 0.2 litres, FlexiPrint Combi is built for anilox lengths up to 800mm and anilox diameters ranging from 64mm to 150mm.

For sheet- and web-offset printing applications, TRESU has launched its Offset Coating Concept. This comprises the TRESU UniPrint Combi chamber doctor blade E-line and TRESU Coating Circulator and a TRESU Coating Conditioner. This system enables sheet-fed and web offset printers to coat printed products at faster speeds, without the risk of micro-foaming. It is suitable for all possible anilox roll up to 1200mm wide and between 80mm and 250mm in diameter, and at print speeds of up to 300m/min or 18,000 sheets per hour. The circulator automatically adjusts to the coating supply and initiates either a 6-minute or intensive 12-minute cleaning program, enabling fast job changes.

“The proliferation of and increased demand for speciality inks and coatings has made the uniform, smooth lay-down of flexographic inks and coatings a more challenging affair.  TRESU chamber doctor blade technology offers a universal solution that gives assurance of smooth results at high print speeds, safety and minimum make-ready time,” says Henrik Kristensen.