Screen printing is a technique that allows to control and choose the thickness of the ink to be deposited. The ink lines in the ranges of screen printing products that are used in this application are called screen printing inks. The constant request for high performance in terms of adhesion and fastness prompted Grafco to develop a wide range of inks: solvent based, UV, water based, plastisol and silicone based.
There are other remarkable properties that are quite unique for the industry and that come from the above mentioned screen printing key factors:
Using inks with special, silver-based conductive pigments, it is possible to print on flexible materials, like polyester or polycarbonate, conductive circuits that are used in the production of membrane and capacitive keyboards.
Similarly, by using special high opacity, non-conductive black inks in the production of screen printing inks, it is possible to obtain completely black, backlit appliance panels with touch-sensitive controls (capacitive keyboards).
By using photoluminescent screen printing inks it is possible to obtain prints that once exposed to light and then taken back into dark, emit visible light even for a long period of time. The typical employment is in the print of indicators and equipment markers used in the aeronautical and motorcycle sectors or in the production of safety signs used in the naval sector.
Using screens with high photoemulsion thickness and special UV, high thixotropy screen printing inks, it is possible to produce relief prints (Braille) that can be read by visually impaired people. The UV screen printing inks and varnishes feature a remarkably high drying speed, since they solidify in a split second once they are exposed to UV light. This kind of UV screen printing ink has been long used in sectors that require high production, like industrial packaging, paper-making and the production of fine labels for the wine industry.
Only through screen printing we can nowadays obtain the wide range of special effects with screen printing products that have been specially designed to allow glossy, matt, satin finishings, with relief effects, glitter effects, metallic, iridescent, luminescent, thermochromic, photochromic, retroreflective, soft touch and many more that are used in the industry.
The solvent screen printing inks have as target and intended use, the decoration in industrial applications, where the highest performance is required in terms of fastness and adhesion on various materials with the highest achievable resistance in the outdoor exposure tests. For many years Grafco has been specially optimizing and re-formulating this range of products to meet the requirements of many industrial sectors and the recent demand for the reduction of the environmental impact and utmost respect for users’ health.
The water based screen printing inks for textile printing must ensure excellent opacity, washing fastness, and given their wide use in the clothing industry, meet the requirement for exemption from harmful substances, according to various European regulations like Oekotex or ZDHC.
The plastisol inks for T-shirt have been formulated to combine user friendliness, high opacity and soft hand on fabrics normally used for promotional T-shirts. These features and the fact that the the ink doesn’t dry on the screen during production, lead the screen printers to use the plastisol screen printing inks when high production speed is required with automatic carousel machines like for instance for the promotional apparel.
The silicone based screen printing inks feature a very soft hand, rubbery, braking and extremely soft. This kind of ink is used when it is necessary to have high elasticity and a barrier effect to the migration of the dyes dispersed in the polyester fabrics especially used in the sports industry.
Beside the direct printing (screen printing on T-shirts or other items), the screen printing is also used in the production of screen printing transfers.
In this case the screen printing inks for transfer can be solvent based, water based or silicone based. The transfer print involves production with screen printing machines using these inks for screen printing transfer on specially coated paper or polyester film to ease the transfer during the hot press procedure. These transfer inks, once applied, must be dried and polymerised on these substrates and afterwards, when the market requires it, they are applied through a hot press on the selected material.