Original scientific paper
Measurement of thermo-elastic behavior of some paper substrates and thermal behavior of blanket to analyze Offset Printing system
Shilpi Naskar
; 1Department of Printing Engineering, Jadavpur University, Salt Lake Campus, Kolkata-700 106, India
*
Kanai Chandra Paul
; 1Department of Printing Engineering, Jadavpur University, Salt Lake Campus, Kolkata-700 106, India
* Corresponding author.
Abstract
applications. The primary function is to differentiate between image area and non-image. One of the secondary functions is to cool down the adjacent cylinder surfaces which in case of waterless offset are provided by water cooling jacket. When the water is transferred from blanket to the paper surface, due to moisture absorption the paper increases in size in micron level. This may create registration problem. There are already few mechanisms are present to overcome this problem. To calculate the actual expansion of paper due to moisture change and thermal differences in paper as well as expansion of the blanket due to the temperature differences because of high speed of offset machine and friction between cylinders, the different thermal properties of the paper and blanket such as coefficient of linear expansion, thermal conductivity, specific heat and elastic properties such as poisson’s ratio, modulus of elasticity, etc. need to be measured. The present investigations have been confined to the effect of heat on the paper as well as blanket surface which can affect the print quality. The measurement of some of the thermal and elastic properties of the two different types of paper and thermal properties of blanket has been measured. It has been found that thermal conductivity and specific heat of the paper usually have decreasing tendency with increasing temperature. The thermal conductivity and specific heat of the blanket also have a decreasing tendency with increasing temperature. The co-efficient of thermal expansion of the paper samples increases rapidly with increase in temperature in the sub-zero temperature range followed by it remains either constant or decreases slowly depending on the type of paper.
Keywords
Hrčak ID:
324936
URI
Publication date:
23.12.2024.
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