Impregnation of Paper Sheets in Vinyl Acetate/Vinyl Chloride Copolymer Solution

Abstract

Bleached wood pulp paper sheets were impregnated in a solution of methylene chloride containing different concentrations of vinyl acetate/vinyl chloride copolymer (2-6 gm/100 ml) for different time intervals (5-60 seconds). The effects of polymer concentration and dipping time on the retained polymer on paper sheets were determined. The effects of heating (softening) treated paper sheets at different temperatures [(100, 110, and 12000) for five minutes and at 110°C for different time intervals (3-15 minutes)] on the physical properties of paper sheets were also investigated. The physical properties of the impregnated paper sheets were highly improved. Breaking length increased from 2.2 to 5.4 km, burst factor increased from 12 to 38, tear factor increased from 64 to 105, and water absorbance decreased from 175 to 46. Softening temperature, heating time, and retained polymer play an important role in the improvement of the physical properties of paper sheets.