Printing mechanical

Auhom WJ (2008) Retention agents and stock deaerators in the production of mechanical printing papers. In Chemical additives for the production of pulp paper functionally essential - ecologically beneficial. ZELLCHEMEMG Technical Committee Chemical Additives CHAD, Deutscher Fachverlag, Frankfurt, p. 45-59... 

Letterpress printing is the oldest of the mechanical printing processes and its most notable advance was the casting of movable type by Gutenberg in 1455. It has been developed from a slow reciprocating flatbed process to an extremely fast technique using rotary cylinders. Only thin films of ink can be deposited but they can be printed with great accuracy and evenness of deposit over a very wide area of print. The substrate can be in the form of a sheet, web, or cylinder... 

Condition of Sale All rights reserved. This publication may not be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, printing, photocopying, recording or otherwise, without the prior permission of the publisher. 

In addition to writing devices such as pens, a plethora of mechanical printing devices also deliver inks. Two decades ago, the term mechanical printing would have referred principally to one device the typewriter. Computer technology has changed this situation, and now mechanical (as opposed to handwritten) documents have become much more important in society and consequently much more common as forms of physical evidence. For the forensic chemist however, the common theme remains inks, dyes, and pigments. This section approaches mechanical printing from this perspective. 

MechanicaL Printed circuit boards are rarely subjected to mechanical tests that could cause electrical failures however, adhesion of both Cu and solder mask to the laminate is critical and is often tested. Loss of solder mask adhesion can provide a place for corrodants and moisture to accumulate, which can be the cause of electrical failures when the board is exposed to temperature and humidity. 

The steps during printing include transfer of the ink to the plate, its transfer to the receiving substrate or paper, and print drying. Mechanical printing uses the rotary principle. This means that printing ink is transferred to the paper in a nip between two rotating cylinders (Fig. 7.3.). Ink transfer between flat surfaces or a... 

---