Pulp and Paper 3097 



Milk carton and food service paperboard (bleached) includes solid 

 bleached paperboard for conversion into milk cartons, heavyweight cups, and 

 round nested food containers, plates, dishes, and trays; also used for packaging 

 moist, liquid, or oily foods. 



Other paperboard (bleached) is solid paperboard for conversion into pack- 

 aging of blister packs, tubes, and other products not classified above. Also used 

 for industrial products not classified under bleached bristols. 



Semichemical paperboard contains not less than 75 percent virgin wood 

 pulp, the predominant portion of which is produced by a semichemical process. 



Recycled paperboard is manufactured from a predominance of recycled 

 fibers from various grades of paper stock, and sometimes including a very minor 

 portion of virgin fibers. 



Gypsum wallboard facing is recycled paperboard manufactured for use as 

 liner or facing on gypsum board and plasterboard; the paperboard may be white, 

 cream, gray, blue, or other color. 



Other paperboard (recycled) is recycled paperboard with the same charac- 

 teristics as paperboard for bending or non-bending packaging but for non- 

 packaging uses; also includes recycled paperboard for end uses not otherwise 

 classified, such as tags, file folders, tubes, cans, drums, match stems, tablet 

 backs, and toys. 



These brief definitions are presented as useful in visualizing the scope of the 

 industry and in interpreting industry statistics; they do not fully describe the 

 products. Readers interested in more complete descriptions are referred to The 

 Dictionary of Paper published by the American Paper Institute ( 1 980) , and to the 

 38th Annual Paper Yearbook, 1980, published by Harcourt and Brace, New 

 York. 



25-3 OVERVIEW OF HARDWOOD PULPING 

 AND SHEET FORMING AND DRYING 



Conversion of hardwoods into paper or paperboard involves freeing individ- 

 ual fibers by pulping and bleaching processes that remove much of the binding 

 materials present in solid wood, beating these fibers to promote flexibility and 

 bonding, and formation and drying of prepared fibers into sheets. 



