Dried singulated crosslinked cellulose pulp fibers

#The present invention relates to a dried singulated crosslinked cellulose pulp fiber product made using a jet drier to dry the pulp.

#Dried singulated cellulose pulp fibers are desirable for many products from absorbent personal articles to a reinforcer in concrete. Currently, in the most common process of making singulated fibers, a roll of conventional pulp fibers is hammermilled into singulated fibers. This process is energy and time intensive, requiring many steps and pieces of processing equipment. Each piece of processing equipment requires a significant capital expenditure and occupies valuable factory floor space. Further, the current hammermilling process often produces fibers with undesirable physical properties, such as low kink, curl, and twist.

#This dry singulated pulp will also contain knots of fiber, sometimes referred to as nits or nodules. Knots are fiber clumps that remain strongly adhered to one another as can be seen by placing a small portion of pulp into a clear beaker of water and stirring the water to mix the fibers. Most of the fiber will mix into the water as singular fibers, however there will be fiber clumps that are readily visible. The fiber clumps or knots are undesirable by-products of the hammermilling process. The amount of knots in a pulp that has been hammermilled can be quantified by using a screening system with acoustical energy used as the means to classify the fiber into amounts of knots, accepts and fines. It is desirable to have low knots and fines and high accepts where the accepts are the singulated fibers.

#The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

#FIG. 1 is a schematic diagram of a drying system constructed in accordance with the present invention suitable for carrying out the process in the present invention;

#FIG. 2 is a schematic view of the drying system of the present invention with a cross section view of a jet drier and a fiber separation station;

#The present invention provides for processes and apparatus for the drying, treatment, and singulation of pulp into individual fibers with low interlocked fibers, knots or nodules. As used herein the term “dried” in regards to fibers, is a term of art generally indicating a weight percentage of water between 2% and 10%, but may fall above or below this range. As used herein the term “air” is not limited to pure air but may include any gas consistent with the present invention. As used herein the term “consistency” means the percentage of solids content of a liquid and solid mixture. The specific examples set forth below are directed to the drying, treatment, and singulation of cellulose pulp fibers. However, it should be understood that the present invention is also suitable for use in processing other types of natural fibers and/or synthetic fibers.

#The present invention comprises a drying system having a jet drier designed to dry wet pulp directly from a pulp mill to a singulated fiber product. Referring to FIG. 1, a drying system 10 constructed in accordance with the present invention includes a jet drier 20, a pulp supply station 40, an air supply station 90, a fiber separation station 100, and a fiber collection station 160.

#The pulp supply station 40 is coupled in flow communication with the jet drier 20. The pulp supply station 40 receives supply pulp from a pulp supply source 42 and provides a feed pulp to the jet drier 20 via a pulp feed conduit 44. The air supply station 90 is coupled in flow communication with the jet drier 20. The air supply station 90 receives supply air from an air supply source 92 and provides feed air via an air feed conduit 94 to the jet drier 20. The jet drier 20 is coupled in flow communication with the fiber separation station 100 via outlet flow conduit 30. The jet drier 20 exhausts outlet air, substantially dried and singulated fibers, and fines to the fiber separation station 100 via outlet flow conduit 30. The fiber separation station 100 is coupled in flow communication with the fiber collection station 160. The fiber separation station 100 separates the outlet air from the fibers, and may also separate a portion of the fines from the fibers. The fibers from the fiber separation station 100 are delivered to the fiber collection station 160.