Cost Comparison Of Radiation Vs. Thermal Curing For Particle Board Coatings, Offset Printing Inks And Special Paper Coatings

Introduction

Ultraviolet (UV) and electron beam (EB) curable coatings and printing inks are based on solventless, 100% polymerizable formulations. The emission of volatile organic compounds (VOC's) is avoided or reduced to auxilary processes as e.g. washing. Thus, printing and coating technologies using radiation curing meet the requirements of current VOC emission regulations. ,An other important feature which favors radiation curing over thermal drying is the high energy density generated by UV and EB sources accompanied by a controlled energy absorption within the layer to be cured. As a result of these characteristics specific energy consumption and floor space requirements are reduced if radiation curing is applied and high product speeds can be obtained.

Due to the broad range of current radiation curing applications, it is very difficult to derive reliable, general conclusions about the economical benefits of radiation curing. Thermal drying
followed by solvent recovery or incineration or the use of waterbased coating systems are typical techniques applied to reduce VOC emissions. These advanced techniques should be taken into account if one, wishes to compare radiation curing and conventional thermal drying. Our institute is operating different pilot scale units for EB- and UV- curing of coatings and printing inks. The pilot scale units have been build to demonstrate the technology of radiation curing under (nearly) industrial conditions, to bridge the gap between laboratory work and industrial application and to gain data on the process productivity, economy and ecology. Here we report on three examples of the application of radiation curing. Cost comparisons with thermal drying were based on data obtained or extrapolated from pilot operations.