Studies On The Mechanism Of Effect Of PSA Properties On Screenability And Stickies Control In Secondary Fiber Recycling

The relationships between surface chemical properties, adhesion properties, mechanical properties of Press Sensitive Adhesives(PSAs) and shape, size of stickies from PSAs, and the effect of those properties on screenability of PSAs were studied in this dissertation. On the basis of the results, some benign PSAs were developed. The methods of stickies control were also discussed in this paper.The study showed that the PSA with better distortion properties, high tack and peel adhesion could be easily screened in the waste paper recycling process. Distortion properties and tack are the most important factors, and peel adhesion takes second place. When the tensile strength of PSA is low, it has no effect on screenability of PSA. When the tensile strength of PSA is higher than a certain value, 5N/mm2, even though the PSA has worse distortion properties, lower tack and peel adhesion, the PSA will be strong and the screenability of the PSA will be good. Shear strength and surface chemical properties have no effect on the screenability of PSA. The shape of stickies from the PSA with better distortion properties, high tack and peel adhesion strength is ball or stick, and the size of this kind of stickies is larger, so the stickies is easily screened. The shape of stickies from the PSA with worse distortion properties, low tack and peel adhesion is flake and little dot, so this kind of stickies is difficult screened.Tack, peel adhesion and distortion properties could be enhanced by tackifier. Screenability of PSA could be improved by the tackifier which does not dissolve in high alkaline solution. In a certain ranger, the more dosage of tackifier in PSA, the higher screenability of PSA.As to the PSA with worse distortion properties, low loop tack and peel...