The sole function of the anilox is to ensure that a consistent amount of ink is delivered onto the printing plate, time after time. If the anilox are not clean or kept in perfect condition, this will reduce the quantity of ink transferred, potentially causing one of the common flexo printing defects we see today – e.g. Low print density, Pinholing, mottled print etc. Also if you don’t monitor anilox rolls, it is sometimes easy to lose track of anilox specifications, perhaps selecting an anilox roll or sleeve which is not best suited to your printing requirements. Hence for flexo printers who want to optimise print quality, anilox selection and regular care & maintenance are essential to ensure your anilox are delivering consistent print performance using your unique graphics, inks and substrates. As a leader in flexo consultancy, Pamarco recommend three steps which should be adhered by all printers who seek to maximise print performance.
Pamarco prides itself in helping to reduce downtime, improve efficiency and save money for global converters, and encourages all printers to follow these guidelines as they seek to enhance their own printing capabilities.
Step 1 – Measure (Analysis of anilox roll/sleeve specification & condition)
The first step in the process is to establish exactly the current condition of your anilox. As all flexo printers know, even with careful handling and use, Anilox cells can be prone to damage, wear and ink plugging, (a build-up of dry ink within the cells), and all of these have an negative effect on achieving consistent print performance. Low print density is often an indication of low anilox cell volume, indicating that anilox could be dirty and subject to plugging, therefore it is essential that regular inspection and measurement of anilox is initiated. So what are the most effective techniques available?
Pamarco offer several low cost methods to measure anilox cell specification and condition, these being:
a) Direct measurement with microscope,
b) Direct cell volume measurement with anilox test strips
c) Pamarco’s microfax and remote laboratory analysis.
Using a low cost x200 magnification Microscope, and a simple inspection guide from Pamarco, printers cannot only identify most of the critical selection parameters of the anilox such as screen count and cell angle, but can also highlight if the anilox cells looks worn or have signs of ink plugging. Secondly, by the use of anilox cell volume test strips, and Pamarco’s Screen:Cell Volume selector, printers can also obtain an immediate indication of the current anilox cell volume. Although it can be argued that both of these techniques have some limitations of accuracy, both of these simple techniques can be carried out on press or in the press room and they provide the busy printer with low cost, instant information. This can often be essential so the printer can make instant informed decisions about whether the anilox is suitable for use in the press or if it needs cleaning or rectification work.
For a more accurate and considered approach to anilox measurement, Pamarco can provide an anilox audit service using Microfax™ and remote laboratory analysis. This market leading anilox audit programme involves taking a direct microfax impression on the anilox surface. This step can be carried out by a Pamarco technician or by one of your own operators following simple microfax audit training. The microfax takes a perfect impression of the anilox roll surface, which can then be analysed in Pamarco’s specialist laboratory. In a few days, you will receive a full inspection report of the anilox condition, together with recommendations on any next steps for repair or maintenance of the anilox to suit your individual needs.
Step 2 – Clean (Deep cleaning of anilox rolls/sleeves)
At some stage in the lifetime of the anilox, it will be essential to carry out periodic deep cleaning. This intensive cleaning, routine ensures all ink debris is removed from the cells and your anilox remains in excellent condition, performing at maximum potential for the longest period of time. Pamarco recommend that deep cleaning is implemented as part of regular maintenance schedule and is carried out on a weekly, monthly or quarterly basis, to suit your individual printing requirements.
Deep cleaning can be carried out using a variety of cleaning methods including;
- Ultrasonic cleaning; an off press cleaning technique which uses a combination of ultrasound and cleaning solutions to deep clean single multiple rolls and sleeves;
- Chemical rinse & high pressure spray: Also an off press method generally cleaning single rolls using a combination of chemical rinse, to break down dried ink, followed by high pressure rising using water
- Sani-Blast media systems; A versatile and environmentally safe system which can be carried out either in press or off-press using high pressure bicarbonate soda;
- Lasering, a non-abrasive technique (on or off press system) using a defocussed laser beam to vaporise dried ink from the cells
- Manual cleaning with concentrated solutions, again can be carried out on-press or off press.
Pamarco and our industry partners, offer a full range of deep cleaning solutions, one of which will be perfect for your needs.
Step 3 – Maintain (Daily cleaning/regular maintenance of anilox rolls)
So once you know exactly the condition & specification of your anilox rolls, and you have at your disposal, a good, cost effective deep cleaning regime, the important step is to keep the anilox in good condition on a daily basis. This regular cleaning ensures not only the best day to day and job to job print consistency, but also extends the period between deep cleaning cycles. Pamarco highly recommend setting up and documenting daily cleaning routines using the press inking wash-up systems. These regimes can be carried out at colour or job changes or at the start or end of production shift periods and Pamarco can provide a wide range of cleaning solutions, suitable for use with water, solvent based or UV inks.
So if you are a flexo printer looking to optimise your print performance, save money on press downtime and replacement of anilox rolls, Pamarco highly recommend that you take note of these 3 key steps to improve print consistency and overall quality.
Measure, Clean, Maintain – it’s that simple.
For more information about our cleaning solutions range please contact our Solutions Customer Service Manager, Sandra Rathbone via email at Sandra.email@example.com
Graham Racey – Distribution Sales Manager, Pamarco EMEA
Audits are critical for the proper care and maintenance of Anilox rolls. In this video, one of our experts provides some information on the basics of how an audit is taken and what you can expect after the audit. He also takes a look at why they are so important.