|
Kiwo - Cleaning Stencils used for Screenprinting Glass |
|
|
Printing glass and ceramic demands the highest requirements of the printing process. In this respect, next to high workflow standardisation, stencil cleaning is an important focal point. For only with consistently high stencil quality can the required quality levels be achieved. For printing glass for architectural use, mirrors, Ceran®hobs, windscreens, rear and side windows of cars, the screenprinting process is the current state of the art.
Printing pastes, whether they are solvent-based, can be thinned with water, UV and IR curing as well as innovations of ink manufacturers, constantly present the screenprinter with new challenges in the field of screen cleaning. Usually ink is simply cleaned off the screen (manual cleaning or running it through an automatic screen washing unit), which is stored after it has been dried. Apart from being able to clean combination ink systems (water and solvent-based) well, suitable screen cleaners should also fulfil the following requirements:
● Manual screen cleaning on press / screen opener: flashpoint >40°C to EN1010 / BGI 801
● Screen cleaners for automatic screen cleaning units: flashpoint >55°C to EN1010 / BGI 801
● Good ink cleaning results for combined ink systems especially for automatic screen cleaning units (one cleaner for all printing media)
● Good drying properties of the cleaned screen: Screen cleaners with a flashpoint >40°C: <10 mins drying time Screen cleaners with a flashpoint >55°C: <20 mins drying time
● Free from non-drying components (e.g. emulsifiers, VOCs)
● Mild odour
● Regenerating the used screen cleaners through distillation (preferably vacuum distillation).
KIWO CLEANLINE® solvent cleaners, e.g. KIWOCLEAN LM 657, which are used in screen washing units, are manufactured with high conductibility (>1µS/m according to BGR132), to reduce the danger of electrostatic charging. In order to restore conductibility after distillation, KIWOMIX LA 35 (a conductibility additive) has to be added. KIWOMIX LA 35 cannot be distilled. The use of a screen cleaner, which is ideally suitable for printing media used in glass printing, ensures consistently high stencil quality and a standardised workflow in the area of screen cleaning. This will considerably reduce so-called ghost images or print blemishes caused by residual dried-in printing paste on the screen mesh.
www.kiwo.de
|
winners booklet