Abstract: The present process produces a long fiber suitable for making various paper products. The long fiber is derived from Crotalaria juncea. The processing consists of a particular technique for preparing the fiber for digestion and a particular digestion sequence. In the preparation of the fiber for digestion it is dried to less than about 30 percent moisture, moist depithed, washed and wet depithed. The fiber is then processed at a high caustic concentration using a sequence of digestion-pressure reduction-digestion. Optionally there can be a third stage of digestion with a pressure reduction prior to the digestion. After digestion has been completed the fiber is refined and sent to blowdown. The fiber is then screened, washed and bleached. The resulting long fiber will product a high quality paper or is admixed with short fibers and various paper products can be made.

Abstract: Bamboo can be formed into a suitable pulp if prior to digestion it undergoes a process of shredding, washing and wet depithing. The fibers are then chemically digested preferably by a process which uses rapid pressure drops to open the fibers using the energy contained in the wet superheated fibers.

Abstract: The brightness of a thermomechanical pulp can be improved if a serial multiple blowdown technique is used and a bleachant is present at an effective concentration throughout the thermomechanical pulping process.

Abstract: The fiber depither consists of an upper array of feeder blades and a lower array of fan blades. These blades remove more particulate while resulting in less fiber damage.

Abstract: The debris and pith removal from bagasse fiber is significantly enhanced by the flow of fiber from one depithing zone into a fiber washing zone and then to a second depithing zone without any intermediate settling of piling of the fiber. The fiber is maintained in a separated condition throughout the first depithing zone, the washer and the subsequent depithing zone. The result is a bagasse fiber having a greater quantity of the debris and pith removed with much less fiber damage.

Abstract: The pith removal from bagasse fiber is significantly enhanced by the flow of fiber directly from one depithing zone to a second depithing zone without any intermediate settling or pilings of the fiber. The fiber is maintained in a separated condition during the flow from one depithing zone to another depithing zone. The result is a bagasse fiber having a greater quantity of the pith removed with less fiber damage. It is also advantageous to provide a number of conveyors to transport fibrous material to a dual zone depithers and for the removal of depithed fiber and pitch from these depithers. This reduces fiber handling before, during and after depithing.

Abstract: Method for cleaning fibrous vegetable materials to remove trash components (such as coarse sand, stones, rocks, metallic particles, shives, dirt and the like).