Agfa Graphics NV developed the “Makalu” technology, initially, to produce flexographic print masters (plates or sleeves) by means of 3D printing of a curable liquid. The patent portfolio consists of 22 patent families related to three areas:
- Fluids: designed for jetting by means of ink jet heads and which can be UV-cured to form elastomeric layers suitable for flexographic printing.
- Hardware: 3-D printer uses an additive, digital, multilayered materials ink jet based process.
- Software: Printing modes, inkjet head design, jetting sequence specifically designed to obtain 3D images on a rotating drum staring from a 2D-image.
Agfa is seeking licensees in two fields: (1) flexographic printing plates and (2) all other applications, however, they are open to working with a single company with interests in both fields. For the Flexo market, the ideal licensee will have a strong market position and openness to further developing the technology, and bringing disruptive technology to market. For other applications, ideal licensees are companies with existing skills and interests in 3D printing inks and/or 3D printing hardware and software. Those interested in printing on cylinders and/or complex surfaces will be particularly intrigued.
A working prototype has been built and resides in one of Agfa’s R&D centers in Belgium.
Technology Benefit Summary:
Benefits of the patented liquids:
- Unique mechanical properties – After curing, the layers show high elasticity…high elongation at break and high resilience
- Minimal shrinkage – The volume shrinkage due to curing is less than 10%
- Solvent resistance – After curing, the layers show a high resistance to organic solvents and low swelling.
- Reliable jetting – The liquids all have very low viscosities (less than 15mPa.s), showing reliable jetting behavior in ink jet printing heads.
- No extractables – The curable liquids contain an oligomeric/polymeric photoinitiator, reducing the possible migration of the photoinitiator in the cured layer and making the layers suitable as packaging material which are ‘food compliant’. Further, the cited properties are achieved without the use of plasticizers. The presence of plasticizers in a cured layer is a disadvantage because this can ‘sweat out’ during use – printing, processing that involves liquids – leading to a decrease in elasticity.
Benefits of the hardware & software elements of the invention:
- Seamless production of complex 3D structures on cylinders, rollers, and sleeves; potentially for continuous wide web application.
- Fine details – 3D surfaces produced can be used to obtain smooth surfaces and/or surfaces with well-defined microstructures and fine details, such as a column having a diameter of 20µm.
Abstracts from some of the issued patents:
- A curable jettable liquid comprising at least one monofunctional monomer, at least 5 wt% of a polyfunctional monomer or oligomer based on the total weight of the curable jettable liquid, at least one plasticizer and at least one photo-initiator, characterized in that a layer of the curable jettable liquid after curing has an elongation at break of at least 5%, a storage modulus E’ smaller than 200MPa at 30Hz and a volumetric shrinkage smaller than 10%.
- A curable jettable fluid for making a flexographic printing master characterized in that the jettable fluid has a viscosity measured at jetting temperature of less than 15 mPa.s and comprises an initiator and at least 50 wt.% of a mixture of a cyclic monofunctional acrylate monomer, a monofunctional urethane acrylate oligomer and a difunctional (meth)acrylate monomer.
- A curable jettable fluid for making a flexographic printing master comprising a cyclic monofunctional acrylate monomer and a difunctional (meth)acrylate monomer characterized in that the fluid further comprises a copolymerisable plasticizing monomer preferably selected from the group consisting of diallyl phthalate and a low Tg monomer of which the corresponding homopolymer has a glass transition temperature (Tg) below 0°C.
- System and method for digital creation of a print master using a multiple printhead unit. A relief print master is created by means of a printhead that jets droplets of a polymerisable liquid on a cylindrical sleeve. The droplets follow a spiral path on the cylindrical sleeve. In a multiple printhead unit, there are different spiral paths associated with the different constituting printheads The distance between these spiral paths is not even in a prior art system. By rotating the printhead under a specific angle, the distance between these spiral paths becomes even. The invention can also be used for the creation of other types of print plates, such as for example offset print plates.
- A relief print master is created by means of a printhead that moves in a slow scan direction. The nozzles of the printhead jet droplets of a polymerisable liquid on a rotating drum. The different nozzles jet droplets simultaneously on different layers that have different diameters. As a result, the droplets jetted by different nozzles travel over different distances before landing. The effect of this is that the droplets undergo different position lag as they land on the different layers. By rotating the printhead in a plane that comprises the central axis of the rotating drum and a nozzle row this effect can be compensated for.