4. Silicones in the Pulp and Paper Industry

Organosiloxane materials can be found throughout the processing of pulp and paper, from the digestion of wood chips to the finishing and recycling of papers. Some examples are: • As digester additives, silicones improve the impregnation of active alkali in the wood chips and improve the cooking • As antifoams, silicones help de-airing or drainage in the pulp washing and papermaking processes • As additives, silicones contribute in the finishing process of paper and tissues • In the recycling of papers, silicones act as de-inking aids Some specific examples are developed here to demonstrate how the properties of silicones can bring benefits as antifoams in the paper pulp-washing process and as softening agents in the treatment of tissue fibers. Antifoam in the Pulp-Washing Process or Brownstock Washing Kraft or sulfate pulping remains the most common chemical process used to produce bleached and unbleached pulp of high quality [1]. The wood chips are impregnated with an alkaline liquor containing NaOH and Na2S and digested at high temperatures. During thi