Unit_6_-_Paper_and_Paperboard (2)

Unit_6_-_Paper_and_Paperboard (2) - The major types of...

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6.5.2.3.1 Semi-chemical Pulping Semi-chemical pulp is produced by a combination of mechanical and chemical processes. The wood chips are soaked in caustic soda or sodium sulfite to soften the lignin and other materials that bind the fibers together and then the pulp is ground mechanically. This 6.5.2.3 Combination Processes There are also processes that combine chemical and mechanical treatment, generally producing products that are intermediate, just as the processes themselves are intermediate.
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Unformatted text preview: The major types of intermediate processes are semi-chemical (also known as chemi-The sulfite process is an acid reaction, unlike the other processes which are alkaline based. The sulfite process is used on both hard and soft woods. This process has limited application and is only used for about 1% of all pulp. Paper made by the sulfite process has strength about midway between paper made by the soda process and the sulfate process. http://www.quindeconsulting.ca/...
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This note was uploaded on 03/04/2012 for the course PKG 101 taught by Professor Haroldhughes during the Spring '08 term at Michigan State University.

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