Pressure transfer inks

The term non-impact applies to those processes which do not rely on pressure to transfer ink from the plate to substrate. Of these, ink-jet is a truly non-contact form of non-impact printing. 

Because of the mechanical limit set by the enormous pressure involved in transferring ink to paper, the platen technique can print only areas up to 510 by 380 mm. However, rotary machines with rollers 2 m long, diameters capable of printing four pages of newsprint per revolution, and running at 40000 rph are producing some of today s newspapers. 

Coolant for transformers and capacitors Dedusting agents, adhesives, pesticide extenders Hydraulic fluids, heat transfer fluids, high-pressure lubricants Ink and dye carriers... 

Alois Senefelder to reproduce literature. The principle applied to early lithography dealt with hydrophobic and hydrophilic surfaces on a smooth lithographic limestone to transfer ink to paper by applying pressure. 

Stamp-Pad Inks. These inks are impregnated into a cloth or foam mbber pad and transferred by pressure to mbber type which is then stamped or impressed against the substrate. The inks must be completely nondrying in the pad and yet dry by rapid penetration into the paper. Since it is desirable that the total ink soak into the stock, dyes are used rather than pigments. The vehicles used are usually glycols. 

Ma.ke-Rea.dy, Because pressure is needed for ink wetting and transfer and because the image elements in letterpress vary in size, the same amount of printing pressure or squeeze exerts more pressure on highlight dots than on shadow dots. This necessitates considerable make-ready to even the impression so that the highlights print correctly and do not puncture the paper. Precision plates and premake-ready systems have helped reduce make-ready time, but it is still appreciable for quaUty printing and is a reason letterpress has been largely replaced by other processes. 

Density and Ink Film Thickness. Because ink film thickness directly impacts color, it is important to control film thickness on press. The amount of ink transferred to paper, along with a related factor, dot gain, which refers to how the halftone dots spread under the pressure of the printing process, is the tool by which a press operator monitors color on press. 

The enthalpy of transfer (aH cj0) ) of the solute between phases can be determined from experiment by a Van t Hoff plot of Ink versus 1/T at constant density.(19) Therefore, the RHS of eq. 22 can be evaluated for a particular fluid mobile phase-solute combination and the slope of Ink at constant pressure as temperature is varied can be predicted. 

MEMS (microelectromechanical systems) are systems with small device sizes of 1-100 pm. They are typically driven by electrical signals. To fabricate such systems materials like semiconductors, metals, and polymers are commonly used. MEMS technology fabrication is very cost-efficient. The structures are transferred by processes, which are applied to many systems on one substrate or even many of them simultaneously. The most important fabrication processes are physical vapor deposition (PVD), chemical vapor deposition (CVD), lithography, wet chemical etching, and dry etching. Typical examples for MEMS are pressure, acceleration, and gyro sensors [28,29], DLPs [30], ink jets [31], compasses [32], and also (bio)medical devices. 

The term "electrostatic technique" tends to be usually associated in many minds with Leyden jars, high voltages and corona wires. There were indeed attempts in the late 1930 s and 1940 s to transfer paste type inks — mainly letterpress -across a gap by means of high voltages, air ionization and ion bombardment. The objective was to eliminate pressure and to permit the use of light weight presses. None of these schemes have found commercial applications. 

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